X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/813fb2f63a553c957e917ede5f119b021d6ce391..refs/heads/master:/osfmk/kern/zalloc.c diff --git a/osfmk/kern/zalloc.c b/osfmk/kern/zalloc.c index f9649749f..9d3349911 100644 --- a/osfmk/kern/zalloc.c +++ b/osfmk/kern/zalloc.c @@ -1,8 +1,8 @@ /* - * Copyright (c) 2000-2016 Apple Inc. All rights reserved. + * Copyright (c) 2000-2020 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ - * + * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in @@ -11,10 +11,10 @@ * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. - * + * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. - * + * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, @@ -22,34 +22,34 @@ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. - * + * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * @OSF_COPYRIGHT@ */ -/* +/* * Mach Operating System * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University * All Rights Reserved. - * + * * Permission to use, copy, modify and distribute this software and its * documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. - * + * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. - * + * * Carnegie Mellon requests users of this software to return to - * + * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 - * + * * any improvements or extensions that they make and grant Carnegie Mellon * the rights to redistribute these changes. */ @@ -62,17 +62,20 @@ * Zone-based memory allocator. A zone is a collection of fixed size * data blocks for which quick allocation/deallocation is possible. */ -#include +#define ZALLOC_ALLOW_DEPRECATED 1 +#if !ZALLOC_TEST #include #include #include #include #include #include -#include #include +#include +#include +#include #include #include #include @@ -83,3335 +86,8888 @@ #include #include #include -#include +#include #include +#include + #include #include #include #include +#include +#include /* C_SLOT_PACKED_PTR* */ #include #include #include /* ml_cpu_get_info */ +#include + #include #include +#include #include -/* - * ZONE_ALIAS_ADDR (deprecated) - */ - -#define from_zone_map(addr, size) \ - ((vm_offset_t)(addr) >= zone_map_min_address && \ - ((vm_offset_t)(addr) + size - 1) < zone_map_max_address ) +#include +#if KASAN_ZALLOC /* - * Zone Corruption Debugging - * - * We use three techniques to detect modification of a zone element - * after it's been freed. - * - * (1) Check the freelist next pointer for sanity. - * (2) Store a backup of the next pointer at the end of the element, - * and compare it to the primary next pointer when the element is allocated - * to detect corruption of the freelist due to use-after-free bugs. - * The backup pointer is also XORed with a per-boot random cookie. - * (3) Poison the freed element by overwriting it with 0xdeadbeef, - * and check for that value when the element is being reused to make sure - * no part of the element has been modified while it was on the freelist. - * This will also help catch read-after-frees, as code will now dereference - * 0xdeadbeef instead of a valid but freed pointer. - * - * (1) and (2) occur for every allocation and free to a zone. - * This is done to make it slightly more difficult for an attacker to - * manipulate the freelist to behave in a specific way. - * - * Poisoning (3) occurs periodically for every N frees (counted per-zone) - * and on every free for zones smaller than a cacheline. If -zp - * is passed as a boot arg, poisoning occurs for every free. - * - * Performance slowdown is inversely proportional to the frequency of poisoning, - * with a 4-5% hit around N=1, down to ~0.3% at N=16 and just "noise" at N=32 - * and higher. You can expect to find a 100% reproducible bug in an average of - * N tries, with a standard deviation of about N, but you will want to set - * "-zp" to always poison every free if you are attempting to reproduce - * a known bug. - * - * For a more heavyweight, but finer-grained method of detecting misuse - * of zone memory, look up the "Guard mode" zone allocator in gzalloc.c. - * - * Zone Corruption Logging - * - * You can also track where corruptions come from by using the boot-arguments - * "zlog= -zc". Search for "Zone corruption logging" later - * in this document for more implementation and usage information. - * - * Zone Leak Detection - * - * To debug leaks of zone memory, use the zone leak detection tool 'zleaks' - * found later in this file via the showtopztrace and showz* macros in kgmacros, - * or use zlog without the -zc argument. - * + * Set to 0 to debug poisoning and ZC_ZFREE_CLEARMEM validation under kasan. + * Otherwise they are double-duty with what kasan already does. */ - -/* Returns TRUE if we rolled over the counter at factor */ -static inline boolean_t -sample_counter(volatile uint32_t * count_p, uint32_t factor) -{ - uint32_t old_count, new_count; - boolean_t rolled_over; - - do { - new_count = old_count = *count_p; - - if (++new_count >= factor) { - rolled_over = TRUE; - new_count = 0; - } else { - rolled_over = FALSE; - } - - } while (!OSCompareAndSwap(old_count, new_count, count_p)); - - return rolled_over; -} - -#if defined(__LP64__) -#define ZP_POISON 0xdeadbeefdeadbeef +#define ZALLOC_ENABLE_POISONING 0 +#define ZONE_ENABLE_LOGGING 0 +#elif DEBUG || DEVELOPMENT +#define ZALLOC_ENABLE_POISONING 1 +#define ZONE_ENABLE_LOGGING 1 #else -#define ZP_POISON 0xdeadbeef +#define ZALLOC_ENABLE_POISONING 1 +#define ZONE_ENABLE_LOGGING 0 #endif -#define ZP_DEFAULT_SAMPLING_FACTOR 16 -#define ZP_DEFAULT_SCALE_FACTOR 4 - -/* - * A zp_factor of 0 indicates zone poisoning is disabled, - * however, we still poison zones smaller than zp_tiny_zone_limit (a cacheline). - * Passing the -no-zp boot-arg disables even this behavior. - * In all cases, we record and check the integrity of a backup pointer. - */ - -/* set by zp-factor=N boot arg, zero indicates non-tiny poisoning disabled */ -uint32_t zp_factor = 0; - -/* set by zp-scale=N boot arg, scales zp_factor by zone size */ -uint32_t zp_scale = 0; +#if __LP64__ +#define ZALLOC_EARLY_GAPS 1 +#else +#define ZALLOC_EARLY_GAPS 0 +#endif -/* set in zp_init, zero indicates -no-zp boot-arg */ -vm_size_t zp_tiny_zone_limit = 0; +#if DEBUG +#define z_debug_assert(expr) assert(expr) +#else +#define z_debug_assert(expr) (void)(expr) +#endif -/* initialized to a per-boot random value in zp_init */ -uintptr_t zp_poisoned_cookie = 0; -uintptr_t zp_nopoison_cookie = 0; +extern void vm_pageout_garbage_collect(int collect); +/* Returns pid of the task with the largest number of VM map entries. */ +extern pid_t find_largest_process_vm_map_entries(void); /* - * initialize zone poisoning - * called from zone_bootstrap before any allocations are made from zalloc + * Callout to jetsam. If pid is -1, we wake up the memorystatus thread to do asynchronous kills. + * For any other pid we try to kill that process synchronously. */ -static inline void -zp_init(void) -{ - char temp_buf[16]; +extern boolean_t memorystatus_kill_on_zone_map_exhaustion(pid_t pid); - /* - * Initialize backup pointer random cookie for poisoned elements - * Try not to call early_random() back to back, it may return - * the same value if mach_absolute_time doesn't have sufficient time - * to tick over between calls. - * (This is only a problem on embedded devices) - */ - zp_poisoned_cookie = (uintptr_t) early_random(); +extern zone_t vm_map_entry_zone; +extern zone_t vm_object_zone; - /* - * Always poison zones smaller than a cacheline, - * because it's pretty close to free - */ - ml_cpu_info_t cpu_info; - ml_cpu_get_info(&cpu_info); - zp_tiny_zone_limit = (vm_size_t) cpu_info.cache_line_size; +#define ZONE_MIN_ELEM_SIZE sizeof(uint64_t) +#define ZONE_MAX_ALLOC_SIZE (32 * 1024) - zp_factor = ZP_DEFAULT_SAMPLING_FACTOR; - zp_scale = ZP_DEFAULT_SCALE_FACTOR; +struct zone_page_metadata { + /* The index of the zone this metadata page belongs to */ + zone_id_t zm_index : 11; + + /* Whether `zm_bitmap` is an inline bitmap or a packed bitmap reference */ + uint16_t zm_inline_bitmap : 1; - //TODO: Bigger permutation? /* - * Permute the default factor +/- 1 to make it less predictable - * This adds or subtracts ~4 poisoned objects per 1000 frees. + * Zones allocate in "chunks" of zone_t::z_chunk_pages consecutive + * pages, or zpercpu_count() pages if the zone is percpu. + * + * The first page of it has its metadata set with: + * - 0 if none of the pages are currently wired + * - the number of wired pages in the chunk (not scaled for percpu). + * + * Other pages in the chunk have their zm_chunk_len set to + * ZM_SECONDARY_PAGE or ZM_SECONDARY_PCPU_PAGE depending on whether + * the zone is percpu or not. For those, zm_page_index holds the + * index of that page in the run. */ - if (zp_factor != 0) { - uint32_t rand_bits = early_random() & 0x3; - - if (rand_bits == 0x1) - zp_factor += 1; - else if (rand_bits == 0x2) - zp_factor -= 1; - /* if 0x0 or 0x3, leave it alone */ - } - - /* -zp: enable poisoning for every alloc and free */ - if (PE_parse_boot_argn("-zp", temp_buf, sizeof(temp_buf))) { - zp_factor = 1; - } - - /* -no-zp: disable poisoning completely even for tiny zones */ - if (PE_parse_boot_argn("-no-zp", temp_buf, sizeof(temp_buf))) { - zp_factor = 0; - zp_tiny_zone_limit = 0; - printf("Zone poisoning disabled\n"); - } + uint16_t zm_chunk_len : 4; +#define ZM_CHUNK_LEN_MAX 0x8 +#define ZM_SECONDARY_PAGE 0xe +#define ZM_SECONDARY_PCPU_PAGE 0xf - /* zp-factor=XXXX: override how often to poison freed zone elements */ - if (PE_parse_boot_argn("zp-factor", &zp_factor, sizeof(zp_factor))) { - printf("Zone poisoning factor override: %u\n", zp_factor); - } + union { +#define ZM_ALLOC_SIZE_LOCK 1u + uint16_t zm_alloc_size; /* first page only */ + uint16_t zm_page_index; /* secondary pages only */ + }; + union { + uint32_t zm_bitmap; /* most zones */ + uint32_t zm_bump; /* permanent zones */ + }; - /* zp-scale=XXXX: override how much zone size scales zp-factor by */ - if (PE_parse_boot_argn("zp-scale", &zp_scale, sizeof(zp_scale))) { - printf("Zone poisoning scale factor override: %u\n", zp_scale); - } + zone_pva_t zm_page_next; + zone_pva_t zm_page_prev; +}; +static_assert(sizeof(struct zone_page_metadata) == 16, "validate packing"); - /* Initialize backup pointer random cookie for unpoisoned elements */ - zp_nopoison_cookie = (uintptr_t) early_random(); +__enum_closed_decl(zone_addr_kind_t, bool, { + ZONE_ADDR_FOREIGN, + ZONE_ADDR_NATIVE, +}); +#define ZONE_ADDR_KIND_COUNT 2 -#if MACH_ASSERT - if (zp_poisoned_cookie == zp_nopoison_cookie) - panic("early_random() is broken: %p and %p are not random\n", - (void *) zp_poisoned_cookie, (void *) zp_nopoison_cookie); -#endif +/*! + * @typedef zone_element_t + * + * @brief + * Type that represents a "resolved" zone element. + * + * @description + * This type encodes an element pointer as a tuple of: + * { chunk base, element index, element protection }. + * + * The chunk base is extracted with @c trunc_page() + * as it is always page aligned, and occupies the bits above @c PAGE_SHIFT. + * + * The low two bits encode the protection mode (see @c zprot_mode_t). + * + * The other bits encode the element index in the chunk rather than its address. + */ +typedef struct zone_element { + vm_offset_t ze_value; +} zone_element_t; - /* - * Use the last bit in the backup pointer to hint poisoning state - * to backup_ptr_mismatch_panic. Valid zone pointers are aligned, so - * the low bits are zero. - */ - zp_poisoned_cookie |= (uintptr_t)0x1ULL; - zp_nopoison_cookie &= ~((uintptr_t)0x1ULL); +/*! + * @typedef zone_magazine_t + * + * @brief + * Magazine of cached allocations. + * + * @field zm_cur how many elements this magazine holds (unused while loaded). + * @field zm_link linkage used by magazine depots. + * @field zm_elems an array of @c zc_mag_size() elements. + */ +typedef struct zone_magazine { + uint16_t zm_cur; + STAILQ_ENTRY(zone_magazine) zm_link; + zone_element_t zm_elems[0]; +} *zone_magazine_t; + +/*! + * @typedef zone_cache_t + * + * @brief + * Magazine of cached allocations. + * + * @discussion + * Below is a diagram of the caching system. This design is inspired by the + * paper "Magazines and Vmem: Extending the Slab Allocator to Many CPUs and + * Arbitrary Resources" by Jeff Bonwick and Jonathan Adams and the FreeBSD UMA + * zone allocator (itself derived from this seminal work). + * + * It is divided into 3 layers: + * - the per-cpu layer, + * - the recirculation depot layer, + * - the Zone Allocator. + * + * The per-cpu and recirculation depot layer use magazines (@c zone_magazine_t), + * which are stacks of up to @c zc_mag_size() elements. + * + *

CPU layer

+ * + * The CPU layer (@c zone_cache_t) looks like this: + * + * ╭─ a ─ f ─┬───────── zm_depot ──────────╮ + * │ ╭─╮ ╭─╮ │ ╭─╮ ╭─╮ ╭─╮ ╭─╮ ╭─╮ │ + * │ │#│ │#│ │ │#│ │#│ │#│ │#│ │#│ │ + * │ │#│ │ │ │ │#│ │#│ │#│ │#│ │#│ │ + * │ │ │ │ │ │ │#│ │#│ │#│ │#│ │#│ │ + * │ ╰─╯ ╰─╯ │ ╰─╯ ╰─╯ ╰─╯ ╰─╯ ╰─╯ │ + * ╰─────────┴─────────────────────────────╯ + * + * It has two pre-loaded magazines (a)lloc and (f)ree which we allocate from, + * or free to. Serialization is achieved through disabling preemption, and only + * the current CPU can acces those allocations. This is represented on the left + * hand side of the diagram above. + * + * The right hand side is the per-cpu depot. It consists of @c zm_depot_count + * full magazines, and is protected by the @c zm_depot_lock for access. + * The lock is expected to absolutely never be contended, as only the local CPU + * tends to access the local per-cpu depot in regular operation mode. + * + * However unlike UMA, our implementation allows for the zone GC to reclaim + * per-CPU magazines aggresively, which is serialized with the @c zm_depot_lock. + * + * + *

Recirculation Depot

+ * + * The recirculation depot layer is a list similar to the per-cpu depot, + * however it is different in two fundamental ways: + * + * - it is protected by the regular zone lock, + * - elements referenced by the magazines in that layer appear free + * to the zone layer. + * + * + *

Magazine circulation and sizing

+ * + * The caching system sizes itself dynamically. Operations that allocate/free + * a single element call @c zone_lock_nopreempt_check_contention() which records + * contention on the lock by doing a trylock and recording its success. + * + * This information is stored in the @c z_contention_cur field of the zone, + * and a windoed moving average is maintained in @c z_contention_wma. + * Each time a CPU registers any contention, it will also allow its own per-cpu + * cache to grow, incrementing @c zc_depot_max, which is how the per-cpu layer + * might grow into using its local depot. + * + * Note that @c zc_depot_max assume that the (a) and (f) pre-loaded magazines + * on average contain @c zc_mag_size() elements. + * + * When a per-cpu layer cannot hold more full magazines in its depot, + * then it will overflow about 1/3 of its depot into the recirculation depot + * (see @c zfree_cached_slow(). Conversely, when a depot is empty, then it will + * refill its per-cpu depot to about 1/3 of its size from the recirculation + * depot (see @c zalloc_cached_slow()). + * + * Lastly, the zone layer keeps track of the high and low watermark of how many + * elements have been free per period of time (including being part of the + * recirculation depot) in the @c z_elems_free_min and @c z_elems_free_max + * fields. A weighted moving average of the amplitude of this is maintained in + * the @c z_elems_free_wss which informs the zone GC on how to gently trim + * zones without hurting performance. + * + * + *

Security considerations

+ * + * The zone caching layer has been designed to avoid returning elements in + * a strict LIFO behavior: @c zalloc() will allocate from the (a) magazine, + * and @c zfree() free to the (f) magazine, and only swap them when the + * requested operation cannot be fulfilled. + * + * The per-cpu overflow depot or the recirculation depots are similarly used + * in FIFO order. + * + * More importantly, when magazines flow through the recirculation depot, + * the elements they contain are marked as "free" in the zone layer bitmaps. + * Because allocations out of per-cpu caches verify the bitmaps at allocation + * time, this acts as a poor man's double-free quarantine. The magazines + * allow to avoid the cost of the bit-scanning involved in the zone-level + * @c zalloc_item() codepath. + * + * + * @field zc_alloc_cur denormalized number of elements in the (a) magazine + * @field zc_free_cur denormalized number of elements in the (f) magazine + * @field zc_alloc_elems a pointer to the array of elements in (a) + * @field zc_free_elems a pointer to the array of elements in (f) + * + * @field zc_depot_lock a lock to access @c zc_depot, @c zc_depot_cur. + * @field zc_depot a list of @c zc_depot_cur full magazines + * @field zc_depot_cur number of magazines in @c zc_depot + * @field zc_depot_max the maximum number of elements in @c zc_depot, + * protected by the zone lock. + */ +typedef struct zone_cache { + uint16_t zc_alloc_cur; + uint16_t zc_free_cur; + uint16_t zc_depot_cur; + uint16_t __zc_padding; + zone_element_t *zc_alloc_elems; + zone_element_t *zc_free_elems; + hw_lock_bit_t zc_depot_lock; + uint32_t zc_depot_max; + struct zone_depot zc_depot; +} *zone_cache_t; + +static __security_const_late struct { + struct zone_map_range zi_map_range[ZONE_ADDR_KIND_COUNT]; + struct zone_map_range zi_meta_range; /* debugging only */ + struct zone_map_range zi_bits_range; /* bits buddy allocator */ -#if defined(__LP64__) /* - * Make backup pointers more obvious in GDB for 64 bit - * by making OxFFFFFF... ^ cookie = 0xFACADE... - * (0xFACADE = 0xFFFFFF ^ 0x053521) - * (0xC0FFEE = 0xFFFFFF ^ 0x3f0011) - * The high 3 bytes of a zone pointer are always 0xFFFFFF, and are checked - * by the sanity check, so it's OK for that part of the cookie to be predictable. + * The metadata lives within the zi_meta_range address range. + * + * The correct formula to find a metadata index is: + * absolute_page_index - page_index(MIN(zi_map_range[*].min_address)) + * + * And then this index is used to dereference zi_meta_range.min_address + * as a `struct zone_page_metadata` array. + * + * To avoid doing that substraction all the time in the various fast-paths, + * zi_meta_base are pre-offset with that minimum page index to avoid redoing + * that math all the time. * - * TODO: Use #defines, xors, and shifts + * Do note that the array might have a hole punched in the middle, + * see zone_metadata_init(). */ + struct zone_page_metadata *zi_meta_base; +} zone_info; - zp_poisoned_cookie &= 0x000000FFFFFFFFFF; - zp_poisoned_cookie |= 0x0535210000000000; /* 0xFACADE */ - - zp_nopoison_cookie &= 0x000000FFFFFFFFFF; - zp_nopoison_cookie |= 0x3f00110000000000; /* 0xC0FFEE */ +/* + * Initial array of metadata for stolen memory. + * + * The numbers here have to be kept in sync with vm_map_steal_memory() + * so that we have reserved enough metadata. + * + * After zone_init() has run (which happens while the kernel is still single + * threaded), the metadata is moved to its final dynamic location, and + * this array is unmapped with the rest of __startup_data at lockdown. + */ +#if CONFIG_GZALLOC +#define ZONE_FOREIGN_META_INLINE_COUNT 20032 +#else +#define ZONE_FOREIGN_META_INLINE_COUNT 64 #endif -} +__startup_data +static struct zone_page_metadata + zone_foreign_meta_array_startup[ZONE_FOREIGN_META_INLINE_COUNT]; /* - * These macros are used to keep track of the number - * of pages being used by the zone currently. The - * z->page_count is protected by the zone lock. + * The zone_locks_grp allows for collecting lock statistics. + * All locks are associated to this group in zinit. + * Look at tools/lockstat for debugging lock contention. */ -#define ZONE_PAGE_COUNT_INCR(z, count) \ -{ \ - OSAddAtomic64(count, &(z->page_count)); \ -} +static LCK_GRP_DECLARE(zone_locks_grp, "zone_locks"); +static LCK_MTX_EARLY_DECLARE(zone_metadata_region_lck, &zone_locks_grp); -#define ZONE_PAGE_COUNT_DECR(z, count) \ -{ \ - OSAddAtomic64(-count, &(z->page_count)); \ -} - -vm_map_t zone_map = VM_MAP_NULL; - -/* for is_sane_zone_element and garbage collection */ +/* + * Exclude more than one concurrent garbage collection + */ +static LCK_GRP_DECLARE(zone_gc_lck_grp, "zone_gc"); +static LCK_MTX_EARLY_DECLARE(zone_gc_lock, &zone_gc_lck_grp); -vm_offset_t zone_map_min_address = 0; /* initialized in zone_init */ -vm_offset_t zone_map_max_address = 0; +bool panic_include_zprint = FALSE; +mach_memory_info_t *panic_kext_memory_info = NULL; +vm_size_t panic_kext_memory_size = 0; -/* Globals for random boolean generator for elements in free list */ -#define MAX_ENTROPY_PER_ZCRAM 4 -#define RANDOM_BOOL_GEN_SEED_COUNT 4 -static unsigned int bool_gen_seed[RANDOM_BOOL_GEN_SEED_COUNT]; -static unsigned int bool_gen_global = 0; -decl_simple_lock_data(, bool_gen_lock) +/* + * Protects zone_array, num_zones, num_zones_in_use, and + * zone_destroyed_bitmap + */ +static SIMPLE_LOCK_DECLARE(all_zones_lock, 0); +static zone_id_t num_zones_in_use; +zone_id_t _Atomic num_zones; +SECURITY_READ_ONLY_LATE(unsigned int) zone_view_count; -/* VM region for all metadata structures */ -vm_offset_t zone_metadata_region_min = 0; -vm_offset_t zone_metadata_region_max = 0; -decl_lck_mtx_data(static ,zone_metadata_region_lck) -lck_attr_t zone_metadata_lock_attr; -lck_mtx_ext_t zone_metadata_region_lck_ext; +#if KASAN_ZALLOC +#define MAX_ZONES 566 +#else /* !KASAN_ZALLOC */ +#define MAX_ZONES 402 +#endif/* !KASAN_ZALLOC */ -/* Helpful for walking through a zone's free element list. */ -struct zone_free_element { - struct zone_free_element *next; - /* ... */ - /* void *backup_ptr; */ -}; +/* + * Initial globals for zone stats until we can allocate the real ones. + * Those get migrated inside the per-CPU ones during zone_init() and + * this array is unmapped with the rest of __startup_data at lockdown. + */ +/* zone to allocate zone_magazine structs from */ +static SECURITY_READ_ONLY_LATE(zone_t) zc_magazine_zone; /* - * Protects num_zones, zone_array and zone_array_index + * Until pid1 is made, zone caching is off, + * until compute_zone_working_set_size() runs for the firt time. + * + * -1 represents the "never enabled yet" value. */ -decl_simple_lock_data(, all_zones_lock) -unsigned int num_zones; +static int8_t zone_caching_disabled = -1; + +__startup_data +static struct zone_cache zone_cache_startup[MAX_ZONES]; +__startup_data +static struct zone_stats zone_stats_startup[MAX_ZONES]; +struct zone zone_array[MAX_ZONES]; -#define MAX_ZONES 256 -struct zone zone_array[MAX_ZONES]; -static int zone_array_index = 0; +/* Initialized in zone_bootstrap(), how many "copies" the per-cpu system does */ +static SECURITY_READ_ONLY_LATE(unsigned) zpercpu_early_count; -#define MULTIPAGE_METADATA_MAGIC (0xff) +/* Used to keep track of destroyed slots in the zone_array */ +static bitmap_t zone_destroyed_bitmap[BITMAP_LEN(MAX_ZONES)]; -#define PAGE_METADATA_GET_ZINDEX(page_meta) \ - (page_meta->zindex) +/* number of zone mapped pages used by all zones */ +static long _Atomic zones_phys_page_mapped_count; -#define PAGE_METADATA_GET_ZONE(page_meta) \ - (&(zone_array[page_meta->zindex])) +/* + * Turn ZSECURITY_OPTIONS_STRICT_IOKIT_FREE off on x86 so as not + * not break third party kexts that haven't yet been recompiled + * to use the new iokit macros. + */ +#if XNU_TARGET_OS_OSX && __x86_64__ +#define ZSECURITY_OPTIONS_STRICT_IOKIT_FREE_DEFAULT 0 +#else +#define ZSECURITY_OPTIONS_STRICT_IOKIT_FREE_DEFAULT \ + ZSECURITY_OPTIONS_STRICT_IOKIT_FREE +#endif -#define PAGE_METADATA_SET_ZINDEX(page_meta, index) \ - page_meta->zindex = (index); +#define ZSECURITY_DEFAULT ( \ + ZSECURITY_OPTIONS_SEQUESTER | \ + ZSECURITY_OPTIONS_SUBMAP_USER_DATA | \ + ZSECURITY_OPTIONS_SEQUESTER_KEXT_KALLOC | \ + ZSECURITY_OPTIONS_STRICT_IOKIT_FREE_DEFAULT | \ + 0) +TUNABLE(zone_security_options_t, zsecurity_options, "zs", ZSECURITY_DEFAULT); -struct zone_page_metadata { - queue_chain_t pages; /* linkage pointer for metadata lists */ +#if VM_MAX_TAG_ZONES +/* enable tags for zones that ask for it */ +static TUNABLE(bool, zone_tagging_on, "-zt", false); +#endif /* VM_MAX_TAG_ZONES */ - /* Union for maintaining start of element free list and real metadata (for multipage allocations) */ - union { - /* - * The start of the freelist can be maintained as a 32-bit offset instead of a pointer because - * the free elements would be at max ZONE_MAX_ALLOC_SIZE bytes away from the metadata. Offset - * from start of the allocation chunk to free element list head. - */ - uint32_t freelist_offset; - /* - * This field is used to lookup the real metadata for multipage allocations, where we mark the - * metadata for all pages except the first as "fake" metadata using MULTIPAGE_METADATA_MAGIC. - * Offset from this fake metadata to real metadata of allocation chunk (-ve offset). - */ - uint32_t real_metadata_offset; - }; +#if DEBUG || DEVELOPMENT +TUNABLE(bool, zalloc_disable_copyio_check, "-no-copyio-zalloc-check", false); +#endif /* DEBUG || DEVELOPMENT */ +#if CONFIG_ZLEAKS +/* Making pointer scanning leaks detection possible for all zones */ +static TUNABLE(bool, zone_leaks_scan_enable, "-zl", false); +#else +#define zone_leaks_scan_enable false +#endif - /* - * For the first page in the allocation chunk, this represents the total number of free elements in - * the chunk. - * For all other pages, it represents the number of free elements on that page (used - * for garbage collection of zones with large multipage allocation size) - */ - uint16_t free_count; - uint8_t zindex; /* Zone index within the zone_array */ - uint8_t page_count; /* Count of pages within the allocation chunk */ -}; +/*! @enum zprot_mode_t + * + * @brief + * Zone element corruption detection mode. + * + * @discussion + * We use four techniques to detect modification of a zone element + * after it's been freed. + * + * Elements that are in zones can be in 3 possible states: + * - zeroed out (@c ZPM_ZERO) + * - poisoned (@c ZPM_POISON) with the @c ZONE_POISON pattern + * - with a left and right canary (@c ZPM_CANARY). + * + * @c ZPM_AUTO is used when the actual protection for the element is unknown, + * and will be detected looking at the last word of the allocation at validation + * time. + * + * The mode of an element in zones is discovered by looking at its last + * pointer-sized value: + * - 0 means that it is zeroed out + * - @c ZONE_POISON means it is poisoned + * - any other value means it is using canaries. + * + * Elements are zeroed if: + * - the element size is smaller than @c zp_min_size, + * - the owning zone has the @c z_free_zeroes flag set, + * - the chunk backing store is fresh (and was just allocated). + * + * Elements are poisoned periodically for every N frees (counted per-zone), + * if the elements aren't otherwise zeroed out. + * If -zp is passed as a boot arg, poisoning occurs for every free. + * + * Else elements use canaries. When canaries are used, the first and last + * pointer sized values in the allocation are set to values derived from the + * element address and the @c zp_canary nonce. The first @c zp_min_size + * bytes of the elment are also cleared. + * + * Performance slowdown is inversely proportional to the frequency of poisoning, + * with a 4-5% hit around N=1, down to ~0.3% at N=16 and just "noise" at N=32 + * and higher. You can expect to find a 100% reproducible bug in an average of + * N tries, with a standard deviation of about N, but you will want to set + * "-zp" to always poison every free if you are attempting to reproduce + * a known bug. + * + * For a more heavyweight, but finer-grained method of detecting misuse + * of zone memory, look up the "Guard mode" zone allocator in gzalloc.c. + */ +__enum_closed_decl(zprot_mode_t, vm_offset_t, { + ZPM_AUTO, /* element is indeterminate */ + ZPM_ZERO, /* element is zeroed */ + ZPM_POISON, /* element is poisoned */ + ZPM_CANARY, /* element extremities have a canary */ +}); +#define ZPM_MASK ((zprot_mode_t)0x3) -/* Macro to get page index (within zone_map) of page containing element */ -#define PAGE_INDEX_FOR_ELEMENT(element) \ - (((vm_offset_t)trunc_page(element) - zone_map_min_address) / PAGE_SIZE) -/* Macro to get metadata structure given a page index in zone_map */ -#define PAGE_METADATA_FOR_PAGE_INDEX(index) \ - (zone_metadata_region_min + ((index) * sizeof(struct zone_page_metadata))) +/* + * set by zp-factor=N boot arg + * + * A zp_factor of 0 indicates zone poisoning is disabled and can also be set by + * passing the -no-zp boot-arg. + * + * A zp_factor of 1 indicates zone poisoning is on for all elements and can be + * set by passing the -zp boot-arg. + */ +static TUNABLE(uint32_t, zp_factor, "zp-factor", 16); -/* Macro to get index (within zone_map) for given metadata */ -#define PAGE_INDEX_FOR_METADATA(page_meta) \ - (((vm_offset_t)page_meta - zone_metadata_region_min) / sizeof(struct zone_page_metadata)) +/* set by zp-scale=N boot arg, scales zp_factor by zone size */ +static TUNABLE(uint32_t, zp_scale, "zp-scale", 4); -/* Macro to get page for given page index in zone_map */ -#define PAGE_FOR_PAGE_INDEX(index) \ - (zone_map_min_address + (PAGE_SIZE * (index))) +/* + * Zone caching tunables + * + * zc_mag_size(): + * size of magazines, larger to reduce contention at the expense of memory + * + * zc_auto_enable_threshold + * number of contentions per second after which zone caching engages + * automatically. + * + * 0 to disable. + * + * zc_grow_threshold + * numer of contentions per second after which the per-cpu depot layer + * grows at each newly observed contention without restriction. + * + * 0 to disable. + * + * zc_recirc_denom + * denominator of the fraction of per-cpu depot to migrate to/from + * the recirculation depot layer at a time. Default 3 (1/3). + * + * zc_defrag_ratio + * percentage of the working set to recirc size below which + * the zone is defragmented. Default is 50%. + * + * zc_free_batch_size + * The size of batches of frees/reclaim that can be done keeping + * the zone lock held (and preemption disabled). + */ +static TUNABLE(uint16_t, zc_magazine_size, "zc_mag_size()", 8); +static TUNABLE(uint32_t, zc_auto_threshold, "zc_auto_enable_threshold", 20); +static TUNABLE(uint32_t, zc_grow_threshold, "zc_grow_threshold", 8); +static TUNABLE(uint32_t, zc_recirc_denom, "zc_recirc_denom", 3); +static TUNABLE(uint32_t, zc_defrag_ratio, "zc_defrag_ratio", 50); +static TUNABLE(uint32_t, zc_free_batch_size, "zc_free_batch_size", 1024); + +static SECURITY_READ_ONLY_LATE(uintptr_t) zp_canary; +/* + * Perf results for zeroing all non data zones and 2K of data zones + * showed little regression, therefore setting zp_min_size to 2048 + */ +static TUNABLE(uint32_t, zp_min_size, "zclear_size", 2048); +static SECURITY_READ_ONLY_LATE(uint32_t) zone_phys_mapped_max_pages; +static SECURITY_READ_ONLY_LATE(vm_map_t) zone_submaps[Z_SUBMAP_IDX_COUNT]; +static SECURITY_READ_ONLY_LATE(uint32_t) zone_last_submap_idx; -/* Macro to get the actual metadata for a given address */ -#define PAGE_METADATA_FOR_ELEMENT(element) \ - (struct zone_page_metadata *)(PAGE_METADATA_FOR_PAGE_INDEX(PAGE_INDEX_FOR_ELEMENT(element))) +static zone_t zone_find_largest(void); -/* Magic value to indicate empty element free list */ -#define PAGE_METADATA_EMPTY_FREELIST ((uint32_t)(~0)) +#endif /* !ZALLOC_TEST */ +#pragma mark Zone metadata +#if !ZALLOC_TEST -static inline void * -page_metadata_get_freelist(struct zone_page_metadata *page_meta) +static inline zone_id_t +zone_index(zone_t z) { - assert(PAGE_METADATA_GET_ZINDEX(page_meta) != MULTIPAGE_METADATA_MAGIC); - if (page_meta->freelist_offset == PAGE_METADATA_EMPTY_FREELIST) - return NULL; - else { - if (from_zone_map(page_meta, sizeof(struct zone_page_metadata))) - return (void *)(PAGE_FOR_PAGE_INDEX(PAGE_INDEX_FOR_METADATA(page_meta)) + page_meta->freelist_offset); - else - return (void *)((vm_offset_t)page_meta + page_meta->freelist_offset); - } + return (zone_id_t)(z - zone_array); } -static inline void -page_metadata_set_freelist(struct zone_page_metadata *page_meta, void *addr) +static inline bool +zone_has_index(zone_t z, zone_id_t zid) { - assert(PAGE_METADATA_GET_ZINDEX(page_meta) != MULTIPAGE_METADATA_MAGIC); - if (addr == NULL) - page_meta->freelist_offset = PAGE_METADATA_EMPTY_FREELIST; - else { - if (from_zone_map(page_meta, sizeof(struct zone_page_metadata))) - page_meta->freelist_offset = (uint32_t)((vm_offset_t)(addr) - PAGE_FOR_PAGE_INDEX(PAGE_INDEX_FOR_METADATA(page_meta))); - else - page_meta->freelist_offset = (uint32_t)((vm_offset_t)(addr) - (vm_offset_t)page_meta); - } + return zone_array + zid == z; } -static inline struct zone_page_metadata * -page_metadata_get_realmeta(struct zone_page_metadata *page_meta) +static zone_element_t +zone_element_encode(vm_offset_t base, vm_offset_t eidx, zprot_mode_t zpm) { - assert(PAGE_METADATA_GET_ZINDEX(page_meta) == MULTIPAGE_METADATA_MAGIC); - return (struct zone_page_metadata *)((vm_offset_t)page_meta - page_meta->real_metadata_offset); + return (zone_element_t){ .ze_value = base | (eidx << 2) | zpm }; } -static inline void -page_metadata_set_realmeta(struct zone_page_metadata *page_meta, struct zone_page_metadata *real_meta) +static vm_offset_t +zone_element_base(zone_element_t ze) { - assert(PAGE_METADATA_GET_ZINDEX(page_meta) == MULTIPAGE_METADATA_MAGIC); - assert(PAGE_METADATA_GET_ZINDEX(real_meta) != MULTIPAGE_METADATA_MAGIC); - assert((vm_offset_t)page_meta > (vm_offset_t)real_meta); - vm_offset_t offset = (vm_offset_t)page_meta - (vm_offset_t)real_meta; - assert(offset <= UINT32_MAX); - page_meta->real_metadata_offset = (uint32_t)offset; + return trunc_page(ze.ze_value); } -/* The backup pointer is stored in the last pointer-sized location in an element. */ -static inline vm_offset_t * -get_backup_ptr(vm_size_t elem_size, - vm_offset_t *element) +static vm_offset_t +zone_element_idx(zone_element_t ze) { - return (vm_offset_t *) ((vm_offset_t)element + elem_size - sizeof(vm_offset_t)); + return (ze.ze_value & PAGE_MASK) >> 2; } -/* - * Routine to populate a page backing metadata in the zone_metadata_region. - * Must be called without the zone lock held as it might potentially block. - */ -static inline void -zone_populate_metadata_page(struct zone_page_metadata *page_meta) +#if ZALLOC_ENABLE_POISONING +static zprot_mode_t +zone_element_prot(zone_element_t ze) { - vm_offset_t page_metadata_begin = trunc_page(page_meta); - vm_offset_t page_metadata_end = trunc_page((vm_offset_t)page_meta + sizeof(struct zone_page_metadata)); - - for(;page_metadata_begin <= page_metadata_end; page_metadata_begin += PAGE_SIZE) { - if (pmap_find_phys(kernel_pmap, (vm_map_address_t)page_metadata_begin)) - continue; - /* All updates to the zone_metadata_region are done under the zone_metadata_region_lck */ - lck_mtx_lock(&zone_metadata_region_lck); - if (0 == pmap_find_phys(kernel_pmap, (vm_map_address_t)page_metadata_begin)) { - kernel_memory_populate(zone_map, - page_metadata_begin, - PAGE_SIZE, - KMA_KOBJECT, - VM_KERN_MEMORY_OSFMK); - } - lck_mtx_unlock(&zone_metadata_region_lck); - } - return; + return (zprot_mode_t)(ze.ze_value & ZPM_MASK); } +#endif -static inline uint16_t -get_metadata_alloc_count(struct zone_page_metadata *page_meta) +static vm_offset_t +zone_element_addr(zone_element_t ze, vm_offset_t esize) { - assert(PAGE_METADATA_GET_ZINDEX(page_meta) != MULTIPAGE_METADATA_MAGIC); - struct zone *z = PAGE_METADATA_GET_ZONE(page_meta); - return ((page_meta->page_count * PAGE_SIZE) / z->elem_size); + return zone_element_base(ze) + esize * zone_element_idx(ze); } -/* - * Routine to lookup metadata for any given address. - * If init is marked as TRUE, this should be called without holding the zone lock - * since the initialization might block. - */ -static inline struct zone_page_metadata * -get_zone_page_metadata(struct zone_free_element *element, boolean_t init) +__abortlike +static void +zone_metadata_corruption(zone_t zone, struct zone_page_metadata *meta, + const char *kind) { - struct zone_page_metadata *page_meta = 0; - - if (from_zone_map(element, sizeof(struct zone_free_element))) { - page_meta = (struct zone_page_metadata *)(PAGE_METADATA_FOR_ELEMENT(element)); - if (init) - zone_populate_metadata_page(page_meta); - } else { - page_meta = (struct zone_page_metadata *)(trunc_page((vm_offset_t)element)); - } - if (init) - bzero((char *)page_meta, sizeof(struct zone_page_metadata)); - return ((PAGE_METADATA_GET_ZINDEX(page_meta) != MULTIPAGE_METADATA_MAGIC) ? page_meta : page_metadata_get_realmeta(page_meta)); + panic("zone metadata corruption: %s (meta %p, zone %s%s)", + kind, meta, zone_heap_name(zone), zone->z_name); } -/* Routine to get the page for a given metadata */ -static inline vm_offset_t -get_zone_page(struct zone_page_metadata *page_meta) +__abortlike +static void +zone_invalid_element_addr_panic(zone_t zone, vm_offset_t addr) { - if (from_zone_map(page_meta, sizeof(struct zone_page_metadata))) - return (vm_offset_t)(PAGE_FOR_PAGE_INDEX(PAGE_INDEX_FOR_METADATA(page_meta))); - else - return (vm_offset_t)(trunc_page(page_meta)); + panic("zone element pointer validation failed (addr: %p, zone %s%s)", + (void *)addr, zone_heap_name(zone), zone->z_name); } -/* Routine to get the size of a zone allocated address. If the address doesnt belong to the - * zone_map, returns 0. - */ -vm_size_t -zone_element_size(void *addr, zone_t *z) +__abortlike +static void +zone_invalid_element_panic(zone_t zone, zone_element_t ze) { - struct zone *src_zone; - if (from_zone_map(addr, sizeof(void *))) { - struct zone_page_metadata *page_meta = get_zone_page_metadata((struct zone_free_element *)addr, FALSE); - src_zone = PAGE_METADATA_GET_ZONE(page_meta); - if (z) { - *z = src_zone; - } - return (src_zone->elem_size); - } else { -#if CONFIG_GZALLOC - vm_size_t gzsize; - if (gzalloc_element_size(addr, z, &gzsize)) { - return gzsize; - } -#endif /* CONFIG_GZALLOC */ - - return 0; - } + panic("zone element pointer validation failed (elem: %p,%d, zone %s%s)", + (void *)zone_element_base(ze), (int)zone_element_idx(ze), + zone_heap_name(zone), zone->z_name); } -/* - * Zone checking helper function. - * A pointer that satisfies these conditions is OK to be a freelist next pointer - * A pointer that doesn't satisfy these conditions indicates corruption - */ -static inline boolean_t -is_sane_zone_ptr(zone_t zone, - vm_offset_t addr, - size_t obj_size) +__abortlike +static void +zone_page_metadata_index_confusion_panic(zone_t zone, vm_offset_t addr, + struct zone_page_metadata *meta) { - /* Must be aligned to pointer boundary */ - if (__improbable((addr & (sizeof(vm_offset_t) - 1)) != 0)) - return FALSE; + panic("%p not in the expected zone %s%s (%d != %d)", + (void *)addr, zone_heap_name(zone), zone->z_name, + meta->zm_index, zone_index(zone)); +} - /* Must be a kernel address */ - if (__improbable(!pmap_kernel_va(addr))) - return FALSE; +__abortlike +static void +zone_page_metadata_native_queue_corruption(zone_t zone, zone_pva_t *queue) +{ + panic("foreign metadata index %d enqueued in native head %p from zone %s%s", + queue->packed_address, queue, zone_heap_name(zone), + zone->z_name); +} - /* Must be from zone map if the zone only uses memory from the zone_map */ - /* - * TODO: Remove the zone->collectable check when every - * zone using foreign memory is properly tagged with allows_foreign - */ - if (zone->collectable && !zone->allows_foreign) { - /* check if addr is from zone map */ - if (addr >= zone_map_min_address && - (addr + obj_size - 1) < zone_map_max_address ) - return TRUE; +__abortlike +static void +zone_page_metadata_list_corruption(zone_t zone, struct zone_page_metadata *meta) +{ + panic("metadata list corruption through element %p detected in zone %s%s", + meta, zone_heap_name(zone), zone->z_name); +} - return FALSE; - } +__abortlike __unused +static void +zone_invalid_foreign_addr_panic(zone_t zone, vm_offset_t addr) +{ + panic("addr %p being freed to foreign zone %s%s not from foreign range", + (void *)addr, zone_heap_name(zone), zone->z_name); +} - return TRUE; +__abortlike +static void +zone_page_meta_accounting_panic(zone_t zone, struct zone_page_metadata *meta, + const char *kind) +{ + panic("accounting mismatch (%s) for zone %s%s, meta %p", kind, + zone_heap_name(zone), zone->z_name, meta); } -static inline boolean_t -is_sane_zone_page_metadata(zone_t zone, - vm_offset_t page_meta) +__abortlike +static void +zone_meta_double_free_panic(zone_t zone, zone_element_t ze, const char *caller) { - /* NULL page metadata structures are invalid */ - if (page_meta == 0) - return FALSE; - return is_sane_zone_ptr(zone, page_meta, sizeof(struct zone_page_metadata)); + panic("%s: double free of %p to zone %s%s", caller, + (void *)zone_element_addr(ze, zone_elem_size(zone)), + zone_heap_name(zone), zone->z_name); } -static inline boolean_t -is_sane_zone_element(zone_t zone, - vm_offset_t addr) +__abortlike +static void +zone_accounting_panic(zone_t zone, const char *kind) { - /* NULL is OK because it indicates the tail of the list */ - if (addr == 0) - return TRUE; - return is_sane_zone_ptr(zone, addr, zone->elem_size); -} - -/* Someone wrote to freed memory. */ -static inline void /* noreturn */ -zone_element_was_modified_panic(zone_t zone, - vm_offset_t element, - vm_offset_t found, - vm_offset_t expected, - vm_offset_t offset) -{ - panic("a freed zone element has been modified in zone %s: expected %p but found %p, bits changed %p, at offset %d of %d in element %p, cookies %p %p", - zone->zone_name, - (void *) expected, - (void *) found, - (void *) (expected ^ found), - (uint32_t) offset, - (uint32_t) zone->elem_size, - (void *) element, - (void *) zp_nopoison_cookie, - (void *) zp_poisoned_cookie); + panic("accounting mismatch (%s) for zone %s%s", kind, + zone_heap_name(zone), zone->z_name); } -/* - * The primary and backup pointers don't match. - * Determine which one was likely the corrupted pointer, find out what it - * probably should have been, and panic. - * I would like to mark this as noreturn, but panic() isn't marked noreturn. - */ -static void /* noreturn */ -backup_ptr_mismatch_panic(zone_t zone, - vm_offset_t element, - vm_offset_t primary, - vm_offset_t backup) +#define zone_counter_sub(z, stat, value) ({ \ + if (os_sub_overflow((z)->stat, value, &(z)->stat)) { \ + zone_accounting_panic(z, #stat " wrap-around"); \ + } \ + (z)->stat; \ +}) + +static inline void +zone_elems_free_add(zone_t z, uint32_t count) { - vm_offset_t likely_backup; - vm_offset_t likely_primary; + uint32_t n = (z->z_elems_free += count); + if (z->z_elems_free_max < n) { + z->z_elems_free_max = n; + } +} - likely_primary = primary ^ zp_nopoison_cookie; - boolean_t sane_backup; - boolean_t sane_primary = is_sane_zone_element(zone, likely_primary); - boolean_t element_was_poisoned = (backup & 0x1) ? TRUE : FALSE; +static inline void +zone_elems_free_sub(zone_t z, uint32_t count) +{ + uint32_t n = zone_counter_sub(z, z_elems_free, count); -#if defined(__LP64__) - /* We can inspect the tag in the upper bits for additional confirmation */ - if ((backup & 0xFFFFFF0000000000) == 0xFACADE0000000000) - element_was_poisoned = TRUE; - else if ((backup & 0xFFFFFF0000000000) == 0xC0FFEE0000000000) - element_was_poisoned = FALSE; -#endif + if (z->z_elems_free_min > n) { + z->z_elems_free_min = n; + } +} - if (element_was_poisoned) { - likely_backup = backup ^ zp_poisoned_cookie; - sane_backup = is_sane_zone_element(zone, likely_backup); - } else { - likely_backup = backup ^ zp_nopoison_cookie; - sane_backup = is_sane_zone_element(zone, likely_backup); +static inline uint16_t +zone_meta_alloc_size_add(zone_t z, struct zone_page_metadata *m, + vm_offset_t esize) +{ + if (os_add_overflow(m->zm_alloc_size, (uint16_t)esize, &m->zm_alloc_size)) { + zone_page_meta_accounting_panic(z, m, "alloc_size wrap-around"); + } + return m->zm_alloc_size; +} + +static inline uint16_t +zone_meta_alloc_size_sub(zone_t z, struct zone_page_metadata *m, + vm_offset_t esize) +{ + if (os_sub_overflow(m->zm_alloc_size, esize, &m->zm_alloc_size)) { + zone_page_meta_accounting_panic(z, m, "alloc_size wrap-around"); } + return m->zm_alloc_size; +} + +__abortlike +static void +zone_nofail_panic(zone_t zone) +{ + panic("zalloc(Z_NOFAIL) can't be satisfied for zone %s%s (potential leak)", + zone_heap_name(zone), zone->z_name); +} - /* The primary is definitely the corrupted one */ - if (!sane_primary && sane_backup) - zone_element_was_modified_panic(zone, element, primary, (likely_backup ^ zp_nopoison_cookie), 0); +#if __arm64__ +// arm64 doesn't use ldp when I'd expect it to +#define zone_range_load(r, rmin, rmax) \ + asm("ldp %[rmin], %[rmax], [%[range]]" \ + : [rmin] "=r"(rmin), [rmax] "=r"(rmax) \ + : [range] "r"(r)) +#else +#define zone_range_load(r, rmin, rmax) \ + ({ rmin = (r)->min_address; rmax = (r)->max_address; }) +#endif - /* The backup is definitely the corrupted one */ - if (sane_primary && !sane_backup) - zone_element_was_modified_panic(zone, element, backup, - (primary ^ (element_was_poisoned ? zp_poisoned_cookie : zp_nopoison_cookie)), - zone->elem_size - sizeof(vm_offset_t)); +__header_always_inline bool +zone_range_contains(const struct zone_map_range *r, vm_offset_t addr, vm_offset_t size) +{ + vm_offset_t rmin, rmax; /* - * Not sure which is the corrupted one. - * It's less likely that the backup pointer was overwritten with - * ( (sane address) ^ (valid cookie) ), so we'll guess that the - * primary pointer has been overwritten with a sane but incorrect address. + * The `&` is not a typo: we really expect the check to pass, + * so encourage the compiler to eagerly load and test without branches */ - if (sane_primary && sane_backup) - zone_element_was_modified_panic(zone, element, primary, likely_backup, 0); - - /* Neither are sane, so just guess. */ - zone_element_was_modified_panic(zone, element, primary, likely_backup, 0); + zone_range_load(r, rmin, rmax); + return (addr >= rmin) & (addr + size >= rmin) & (addr + size <= rmax); } -/* - * Adds the element to the head of the zone's free list - * Keeps a backup next-pointer at the end of the element - */ -static inline void -free_to_zone(zone_t zone, - vm_offset_t element, - boolean_t poison) +__header_always_inline vm_size_t +zone_range_size(const struct zone_map_range *r) { - vm_offset_t old_head; - struct zone_page_metadata *page_meta; + vm_offset_t rmin, rmax; - vm_offset_t *primary = (vm_offset_t *) element; - vm_offset_t *backup = get_backup_ptr(zone->elem_size, primary); + zone_range_load(r, rmin, rmax); + return rmax - rmin; +} - page_meta = get_zone_page_metadata((struct zone_free_element *)element, FALSE); - assert(PAGE_METADATA_GET_ZONE(page_meta) == zone); - old_head = (vm_offset_t)page_metadata_get_freelist(page_meta); +#define from_zone_map(addr, size, kind) \ + zone_range_contains(&zone_info.zi_map_range[kind], \ + (vm_offset_t)(addr), size) -#if MACH_ASSERT - if (__improbable(!is_sane_zone_element(zone, old_head))) - panic("zfree: invalid head pointer %p for freelist of zone %s\n", - (void *) old_head, zone->zone_name); -#endif +#define zone_native_size() \ + zone_range_size(&zone_info.zi_map_range[ZONE_ADDR_NATIVE]) - if (__improbable(!is_sane_zone_element(zone, element))) - panic("zfree: freeing invalid pointer %p to zone %s\n", - (void *) element, zone->zone_name); +#define zone_foreign_size() \ + zone_range_size(&zone_info.zi_map_range[ZONE_ADDR_FOREIGN]) - /* - * Always write a redundant next pointer - * So that it is more difficult to forge, xor it with a random cookie - * A poisoned element is indicated by using zp_poisoned_cookie - * instead of zp_nopoison_cookie - */ +__header_always_inline bool +zone_pva_is_null(zone_pva_t page) +{ + return page.packed_address == 0; +} - *backup = old_head ^ (poison ? zp_poisoned_cookie : zp_nopoison_cookie); +__header_always_inline bool +zone_pva_is_queue(zone_pva_t page) +{ + // actual kernel pages have the top bit set + return (int32_t)page.packed_address > 0; +} - /* - * Insert this element at the head of the free list. We also xor the - * primary pointer with the zp_nopoison_cookie to make sure a free - * element does not provide the location of the next free element directly. - */ - *primary = old_head ^ zp_nopoison_cookie; - page_metadata_set_freelist(page_meta, (struct zone_free_element *)element); - page_meta->free_count++; - if (zone->allows_foreign && !from_zone_map(element, zone->elem_size)) { - if (page_meta->free_count == 1) { - /* first foreign element freed on page, move from all_used */ - re_queue_tail(&zone->pages.any_free_foreign, &(page_meta->pages)); - } else { - /* no other list transitions */ - } - } else if (page_meta->free_count == get_metadata_alloc_count(page_meta)) { - /* whether the page was on the intermediate or all_used, queue, move it to free */ - re_queue_tail(&zone->pages.all_free, &(page_meta->pages)); - zone->count_all_free_pages += page_meta->page_count; - } else if (page_meta->free_count == 1) { - /* first free element on page, move from all_used */ - re_queue_tail(&zone->pages.intermediate, &(page_meta->pages)); +__header_always_inline bool +zone_pva_is_equal(zone_pva_t pva1, zone_pva_t pva2) +{ + return pva1.packed_address == pva2.packed_address; +} + +__header_always_inline void +zone_queue_set_head(zone_t z, zone_pva_t queue, zone_pva_t oldv, + struct zone_page_metadata *meta) +{ + zone_pva_t *queue_head = &((zone_pva_t *)zone_array)[queue.packed_address]; + + if (!zone_pva_is_equal(*queue_head, oldv)) { + zone_page_metadata_list_corruption(z, meta); } - zone->count--; - zone->countfree++; + *queue_head = meta->zm_page_next; } +__header_always_inline zone_pva_t +zone_queue_encode(zone_pva_t *headp) +{ + return (zone_pva_t){ (uint32_t)(headp - (zone_pva_t *)zone_array) }; +} -/* - * Removes an element from the zone's free list, returning 0 if the free list is empty. - * Verifies that the next-pointer and backup next-pointer are intact, - * and verifies that a poisoned element hasn't been modified. - */ -static inline vm_offset_t -try_alloc_from_zone(zone_t zone, - boolean_t* check_poison) +__header_always_inline zone_pva_t +zone_pva_from_addr(vm_address_t addr) { - vm_offset_t element; - struct zone_page_metadata *page_meta; + // cannot use atop() because we want to maintain the sign bit + return (zone_pva_t){ (uint32_t)((intptr_t)addr >> PAGE_SHIFT) }; +} - *check_poison = FALSE; - - /* if zone is empty, bail */ - if (zone->allows_foreign && !queue_empty(&zone->pages.any_free_foreign)) - page_meta = (struct zone_page_metadata *)queue_first(&zone->pages.any_free_foreign); - else if (!queue_empty(&zone->pages.intermediate)) - page_meta = (struct zone_page_metadata *)queue_first(&zone->pages.intermediate); - else if (!queue_empty(&zone->pages.all_free)) { - page_meta = (struct zone_page_metadata *)queue_first(&zone->pages.all_free); - assert(zone->count_all_free_pages >= page_meta->page_count); - zone->count_all_free_pages -= page_meta->page_count; - } else { - return 0; - } - /* Check if page_meta passes is_sane_zone_element */ - if (__improbable(!is_sane_zone_page_metadata(zone, (vm_offset_t)page_meta))) - panic("zalloc: invalid metadata structure %p for freelist of zone %s\n", - (void *) page_meta, zone->zone_name); - assert(PAGE_METADATA_GET_ZONE(page_meta) == zone); - element = (vm_offset_t)page_metadata_get_freelist(page_meta); +__header_always_inline zone_pva_t +zone_pva_from_element(zone_element_t ze) +{ + return zone_pva_from_addr(ze.ze_value); +} - if (__improbable(!is_sane_zone_ptr(zone, element, zone->elem_size))) - panic("zfree: invalid head pointer %p for freelist of zone %s\n", - (void *) element, zone->zone_name); +__header_always_inline vm_address_t +zone_pva_to_addr(zone_pva_t page) +{ + // cause sign extension so that we end up with the right address + return (vm_offset_t)(int32_t)page.packed_address << PAGE_SHIFT; +} - vm_offset_t *primary = (vm_offset_t *) element; - vm_offset_t *backup = get_backup_ptr(zone->elem_size, primary); +__header_always_inline struct zone_page_metadata * +zone_pva_to_meta(zone_pva_t page) +{ + return &zone_info.zi_meta_base[page.packed_address]; +} - /* - * Since the primary next pointer is xor'ed with zp_nopoison_cookie - * for obfuscation, retrieve the original value back - */ - vm_offset_t next_element = *primary ^ zp_nopoison_cookie; - vm_offset_t next_element_primary = *primary; - vm_offset_t next_element_backup = *backup; +__header_always_inline zone_pva_t +zone_pva_from_meta(struct zone_page_metadata *meta) +{ + return (zone_pva_t){ (uint32_t)(meta - zone_info.zi_meta_base) }; +} - /* - * backup_ptr_mismatch_panic will determine what next_element - * should have been, and print it appropriately - */ - if (__improbable(!is_sane_zone_element(zone, next_element))) - backup_ptr_mismatch_panic(zone, element, next_element_primary, next_element_backup); +__header_always_inline struct zone_page_metadata * +zone_meta_from_addr(vm_offset_t addr) +{ + return zone_pva_to_meta(zone_pva_from_addr(addr)); +} - /* Check the backup pointer for the regular cookie */ - if (__improbable(next_element != (next_element_backup ^ zp_nopoison_cookie))) { +__header_always_inline struct zone_page_metadata * +zone_meta_from_element(zone_element_t ze) +{ + return zone_pva_to_meta(zone_pva_from_element(ze)); +} - /* Check for the poisoned cookie instead */ - if (__improbable(next_element != (next_element_backup ^ zp_poisoned_cookie))) - /* Neither cookie is valid, corruption has occurred */ - backup_ptr_mismatch_panic(zone, element, next_element_primary, next_element_backup); +__header_always_inline zone_id_t +zone_index_from_ptr(const void *ptr) +{ + return zone_pva_to_meta(zone_pva_from_addr((vm_offset_t)ptr))->zm_index; +} - /* - * Element was marked as poisoned, so check its integrity before using it. - */ - *check_poison = TRUE; +__header_always_inline vm_offset_t +zone_meta_to_addr(struct zone_page_metadata *meta) +{ + return ptoa((int32_t)(meta - zone_info.zi_meta_base)); +} + +__header_always_inline void +zone_meta_queue_push(zone_t z, zone_pva_t *headp, + struct zone_page_metadata *meta) +{ + zone_pva_t head = *headp; + zone_pva_t queue_pva = zone_queue_encode(headp); + struct zone_page_metadata *tmp; + + meta->zm_page_next = head; + if (!zone_pva_is_null(head)) { + tmp = zone_pva_to_meta(head); + if (!zone_pva_is_equal(tmp->zm_page_prev, queue_pva)) { + zone_page_metadata_list_corruption(z, meta); + } + tmp->zm_page_prev = zone_pva_from_meta(meta); } + meta->zm_page_prev = queue_pva; + *headp = zone_pva_from_meta(meta); +} - /* Make sure the page_meta is at the correct offset from the start of page */ - if (__improbable(page_meta != get_zone_page_metadata((struct zone_free_element *)element, FALSE))) - panic("zalloc: Incorrect metadata %p found in zone %s page queue. Expected metadata: %p\n", - page_meta, zone->zone_name, get_zone_page_metadata((struct zone_free_element *)element, FALSE)); +__header_always_inline struct zone_page_metadata * +zone_meta_queue_pop_native(zone_t z, zone_pva_t *headp, vm_offset_t *page_addrp) +{ + zone_pva_t head = *headp; + struct zone_page_metadata *meta = zone_pva_to_meta(head); + vm_offset_t page_addr = zone_pva_to_addr(head); + struct zone_page_metadata *tmp; - /* Make sure next_element belongs to the same page as page_meta */ - if (next_element) { - if (__improbable(page_meta != get_zone_page_metadata((struct zone_free_element *)next_element, FALSE))) - panic("zalloc: next element pointer %p for element %p points to invalid element for zone %s\n", - (void *)next_element, (void *)element, zone->zone_name); + if (!from_zone_map(page_addr, 1, ZONE_ADDR_NATIVE)) { + zone_page_metadata_native_queue_corruption(z, headp); } - /* Remove this element from the free list */ - page_metadata_set_freelist(page_meta, (struct zone_free_element *)next_element); - page_meta->free_count--; - - if (page_meta->free_count == 0) { - /* move to all used */ - re_queue_tail(&zone->pages.all_used, &(page_meta->pages)); - } else { - if (!zone->allows_foreign || from_zone_map(element, zone->elem_size)) { - if (get_metadata_alloc_count(page_meta) == page_meta->free_count + 1) { - /* remove from free, move to intermediate */ - re_queue_tail(&zone->pages.intermediate, &(page_meta->pages)); - } + if (!zone_pva_is_null(meta->zm_page_next)) { + tmp = zone_pva_to_meta(meta->zm_page_next); + if (!zone_pva_is_equal(tmp->zm_page_prev, head)) { + zone_page_metadata_list_corruption(z, meta); } + tmp->zm_page_prev = meta->zm_page_prev; } - zone->countfree--; - zone->count++; - zone->sum_count++; + *headp = meta->zm_page_next; - return element; + meta->zm_page_next = meta->zm_page_prev = (zone_pva_t){ 0 }; + *page_addrp = page_addr; + + if (!zone_has_index(z, meta->zm_index)) { + zone_page_metadata_index_confusion_panic(z, + zone_meta_to_addr(meta), meta); + } + return meta; } -/* - * End of zone poisoning - */ +__header_always_inline void +zone_meta_remqueue(zone_t z, struct zone_page_metadata *meta) +{ + zone_pva_t meta_pva = zone_pva_from_meta(meta); + struct zone_page_metadata *tmp; -/* - * Zone info options - */ -#define ZINFO_SLOTS MAX_ZONES /* for now */ + if (!zone_pva_is_null(meta->zm_page_next)) { + tmp = zone_pva_to_meta(meta->zm_page_next); + if (!zone_pva_is_equal(tmp->zm_page_prev, meta_pva)) { + zone_page_metadata_list_corruption(z, meta); + } + tmp->zm_page_prev = meta->zm_page_prev; + } + if (zone_pva_is_queue(meta->zm_page_prev)) { + zone_queue_set_head(z, meta->zm_page_prev, meta_pva, meta); + } else { + tmp = zone_pva_to_meta(meta->zm_page_prev); + if (!zone_pva_is_equal(tmp->zm_page_next, meta_pva)) { + zone_page_metadata_list_corruption(z, meta); + } + tmp->zm_page_next = meta->zm_page_next; + } -void zone_display_zprint(void); + meta->zm_page_next = meta->zm_page_prev = (zone_pva_t){ 0 }; +} -zone_t zone_find_largest(void); +__header_always_inline void +zone_meta_requeue(zone_t z, zone_pva_t *headp, + struct zone_page_metadata *meta) +{ + zone_meta_remqueue(z, meta); + zone_meta_queue_push(z, headp, meta); +} -/* - * Async allocation of zones - * This mechanism allows for bootstrapping an empty zone which is setup with - * non-blocking flags. The first call to zalloc_noblock() will kick off a thread_call - * to zalloc_async. We perform a zalloc() (which may block) and then an immediate free. - * This will prime the zone for the next use. - * - * Currently the thread_callout function (zalloc_async) will loop through all zones - * looking for any zone with async_pending set and do the work for it. - * - * NOTE: If the calling thread for zalloc_noblock is lower priority than thread_call, - * then zalloc_noblock to an empty zone may succeed. - */ -void zalloc_async( - thread_call_param_t p0, - thread_call_param_t p1); +/* prevents a given metadata from ever reaching the z_pageq_empty queue */ +static inline void +zone_meta_lock_in_partial(zone_t z, struct zone_page_metadata *m, uint32_t len) +{ + uint16_t new_size = zone_meta_alloc_size_add(z, m, ZM_ALLOC_SIZE_LOCK); -static thread_call_data_t call_async_alloc; + assert(new_size % sizeof(vm_offset_t) == ZM_ALLOC_SIZE_LOCK); + if (new_size == ZM_ALLOC_SIZE_LOCK) { + zone_meta_requeue(z, &z->z_pageq_partial, m); + zone_counter_sub(z, z_wired_empty, len); + } +} -/* - * Align elements that use the zone page list to 32 byte boundaries. - */ -#define ZONE_ELEMENT_ALIGNMENT 32 +/* allows a given metadata to reach the z_pageq_empty queue again */ +static inline void +zone_meta_unlock_from_partial(zone_t z, struct zone_page_metadata *m, uint32_t len) +{ + uint16_t new_size = zone_meta_alloc_size_sub(z, m, ZM_ALLOC_SIZE_LOCK); -#define zone_wakeup(zone) thread_wakeup((event_t)(zone)) -#define zone_sleep(zone) \ - (void) lck_mtx_sleep(&(zone)->lock, LCK_SLEEP_SPIN, (event_t)(zone), THREAD_UNINT); + assert(new_size % sizeof(vm_offset_t) == 0); + if (new_size == 0) { + zone_meta_requeue(z, &z->z_pageq_empty, m); + z->z_wired_empty += len; + } +} /* - * The zone_locks_grp allows for collecting lock statistics. - * All locks are associated to this group in zinit. - * Look at tools/lockstat for debugging lock contention. + * Routine to populate a page backing metadata in the zone_metadata_region. + * Must be called without the zone lock held as it might potentially block. */ +static void +zone_meta_populate(vm_offset_t base, vm_size_t size) +{ + struct zone_page_metadata *from = zone_meta_from_addr(base); + struct zone_page_metadata *to = from + atop(size); + vm_offset_t page_addr = trunc_page(from); -lck_grp_t zone_locks_grp; -lck_grp_attr_t zone_locks_grp_attr; - -#define lock_zone_init(zone) \ -MACRO_BEGIN \ - lck_attr_setdefault(&(zone)->lock_attr); \ - lck_mtx_init_ext(&(zone)->lock, &(zone)->lock_ext, \ - &zone_locks_grp, &(zone)->lock_attr); \ -MACRO_END + for (; page_addr < (vm_offset_t)to; page_addr += PAGE_SIZE) { +#if !KASAN_ZALLOC + /* + * This can race with another thread doing a populate on the same metadata + * page, where we see an updated pmap but unmapped KASan shadow, causing a + * fault in the shadow when we first access the metadata page. Avoid this + * by always synchronizing on the zone_metadata_region lock with KASan. + */ + if (pmap_find_phys(kernel_pmap, page_addr)) { + continue; + } +#endif -#define lock_try_zone(zone) lck_mtx_try_lock_spin(&zone->lock) + for (;;) { + kern_return_t ret = KERN_SUCCESS; -/* - * Exclude more than one concurrent garbage collection - */ -decl_lck_mtx_data(, zone_gc_lock) + /* All updates to the zone_metadata_region are done under the zone_metadata_region_lck */ + lck_mtx_lock(&zone_metadata_region_lck); + if (0 == pmap_find_phys(kernel_pmap, page_addr)) { + ret = kernel_memory_populate(kernel_map, page_addr, + PAGE_SIZE, KMA_NOPAGEWAIT | KMA_KOBJECT | KMA_ZERO, + VM_KERN_MEMORY_OSFMK); + } + lck_mtx_unlock(&zone_metadata_region_lck); -lck_attr_t zone_gc_lck_attr; -lck_grp_t zone_gc_lck_grp; -lck_grp_attr_t zone_gc_lck_grp_attr; -lck_mtx_ext_t zone_gc_lck_ext; + if (ret == KERN_SUCCESS) { + break; + } -boolean_t zone_gc_allowed = TRUE; -boolean_t panic_include_zprint = FALSE; + /* + * We can't pass KMA_NOPAGEWAIT under a global lock as it leads + * to bad system deadlocks, so if the allocation failed, + * we need to do the VM_PAGE_WAIT() outside of the lock. + */ + VM_PAGE_WAIT(); + } + } +} -vm_offset_t panic_kext_memory_info = 0; -vm_size_t panic_kext_memory_size = 0; +__header_always_inline +struct zone_page_metadata * +zone_element_validate(zone_t zone, zone_element_t ze) +{ + struct zone_page_metadata *meta; + vm_offset_t page = zone_element_base(ze); -#define ZALLOC_DEBUG_ZONEGC 0x00000001 -#define ZALLOC_DEBUG_ZCRAM 0x00000002 -uint32_t zalloc_debug = 0; + if (!from_zone_map(page, 1, ZONE_ADDR_NATIVE) && + !from_zone_map(page, 1, ZONE_ADDR_FOREIGN)) { + zone_invalid_element_panic(zone, ze); + } + meta = zone_meta_from_addr(page); -/* - * Zone leak debugging code - * - * When enabled, this code keeps a log to track allocations to a particular zone that have not - * yet been freed. Examining this log will reveal the source of a zone leak. The log is allocated - * only when logging is enabled, so there is no effect on the system when it's turned off. Logging is - * off by default. - * - * Enable the logging via the boot-args. Add the parameter "zlog=" to boot-args where - * is the name of the zone you wish to log. - * - * This code only tracks one zone, so you need to identify which one is leaking first. - * Generally, you'll know you have a leak when you get a "zalloc retry failed 3" panic from the zone - * garbage collector. Note that the zone name printed in the panic message is not necessarily the one - * containing the leak. So do a zprint from gdb and locate the zone with the bloated size. This - * is most likely the problem zone, so set zlog in boot-args to this zone name, reboot and re-run the test. The - * next time it panics with this message, examine the log using the kgmacros zstack, findoldest and countpcs. - * See the help in the kgmacros for usage info. - * - * - * Zone corruption logging - * - * Logging can also be used to help identify the source of a zone corruption. First, identify the zone - * that is being corrupted, then add "-zc zlog=" to the boot-args. When -zc is used in conjunction - * with zlog, it changes the logging style to track both allocations and frees to the zone. So when the - * corruption is detected, examining the log will show you the stack traces of the callers who last allocated - * and freed any particular element in the zone. Use the findelem kgmacro with the address of the element that's been - * corrupted to examine its history. This should lead to the source of the corruption. - */ + if (meta->zm_chunk_len > ZM_CHUNK_LEN_MAX) { + zone_invalid_element_panic(zone, ze); + } + if (zone_element_idx(ze) >= zone->z_chunk_elems) { + zone_invalid_element_panic(zone, ze); + } -static boolean_t log_records_init = FALSE; -static int log_records; /* size of the log, expressed in number of records */ + if (!zone_has_index(zone, meta->zm_index)) { + vm_offset_t addr = zone_element_addr(ze, zone_elem_size(zone)); + zone_page_metadata_index_confusion_panic(zone, addr, meta); + } -#define MAX_NUM_ZONES_ALLOWED_LOGGING 5 /* Maximum 5 zones can be logged at once */ + return meta; +} -static int max_num_zones_to_log = MAX_NUM_ZONES_ALLOWED_LOGGING; -static int num_zones_logged = 0; +__attribute__((always_inline)) +static struct zone_page_metadata * +zone_element_resolve(zone_t zone, vm_offset_t addr, vm_offset_t esize, + zone_element_t *ze) +{ + struct zone_page_metadata *meta; + vm_offset_t page, eidx; -#define MAX_ZONE_NAME 32 /* max length of a zone name we can take from the boot-args */ + if (!from_zone_map(addr, esize, ZONE_ADDR_NATIVE) && + !from_zone_map(addr, esize, ZONE_ADDR_FOREIGN)) { + zone_invalid_element_addr_panic(zone, addr); + } + page = trunc_page(addr); + meta = zone_meta_from_addr(addr); -static char zone_name_to_log[MAX_ZONE_NAME] = ""; /* the zone name we're logging, if any */ + if (meta->zm_chunk_len == ZM_SECONDARY_PCPU_PAGE) { + zone_invalid_element_addr_panic(zone, addr); + } + if (meta->zm_chunk_len == ZM_SECONDARY_PAGE) { + page -= ptoa(meta->zm_page_index); + meta -= meta->zm_page_index; + } -/* Log allocations and frees to help debug a zone element corruption */ -boolean_t corruption_debug_flag = FALSE; /* enabled by "-zc" boot-arg */ -/* Making pointer scanning leaks detection possible for all zones */ + eidx = (addr - page) / esize; + if ((addr - page) % esize) { + zone_invalid_element_addr_panic(zone, addr); + } -#if DEBUG || DEVELOPMENT -boolean_t leak_scan_debug_flag = FALSE; /* enabled by "-zl" boot-arg */ -#endif /* DEBUG || DEVELOPMENT */ + if (!zone_has_index(zone, meta->zm_index)) { + zone_page_metadata_index_confusion_panic(zone, addr, meta); + } + *ze = zone_element_encode(page, eidx, ZPM_AUTO); + return meta; +} -/* - * The number of records in the log is configurable via the zrecs parameter in boot-args. Set this to - * the number of records you want in the log. For example, "zrecs=10" sets it to 10 records. Since this - * is the number of stacks suspected of leaking, we don't need many records. +/* Routine to get the size of a zone allocated address. + * If the address doesnt belong to the zone maps, returns 0. */ +vm_size_t +zone_element_size(void *addr, zone_t *z) +{ + struct zone *src_zone; -#if defined(__LP64__) -#define ZRECORDS_MAX 2560 /* Max records allowed in the log */ -#else -#define ZRECORDS_MAX 1536 /* Max records allowed in the log */ -#endif -#define ZRECORDS_DEFAULT 1024 /* default records in log if zrecs is not specificed in boot-args */ + if (from_zone_map(addr, sizeof(void *), ZONE_ADDR_NATIVE) || + from_zone_map(addr, sizeof(void *), ZONE_ADDR_FOREIGN)) { + src_zone = &zone_array[zone_index_from_ptr(addr)]; + if (z) { + *z = src_zone; + } + return zone_elem_size(src_zone); + } -/* - * Each record in the log contains a pointer to the zone element it refers to, - * and a small array to hold the pc's from the stack trace. A - * record is added to the log each time a zalloc() is done in the zone_of_interest. For leak debugging, - * the record is cleared when a zfree() is done. For corruption debugging, the log tracks both allocs and frees. - * If the log fills, old records are replaced as if it were a circular buffer. - */ +#if CONFIG_GZALLOC + if (__improbable(gzalloc_enabled())) { + vm_size_t gzsize; + if (gzalloc_element_size(addr, z, &gzsize)) { + return gzsize; + } + } +#endif /* CONFIG_GZALLOC */ + return 0; +} -/* - * Opcodes for the btlog operation field: - */ +/* This function just formats the reason for the panics by redoing the checks */ +__abortlike +static void +zone_require_panic(zone_t zone, void *addr) +{ + uint32_t zindex; + zone_t other; -#define ZOP_ALLOC 1 -#define ZOP_FREE 0 + if (!from_zone_map(addr, zone_elem_size(zone), ZONE_ADDR_NATIVE)) { + panic("zone_require failed: address not in a zone (addr: %p)", addr); + } -/* - * Decide if we want to log this zone by doing a string compare between a zone name and the name - * of the zone to log. Return true if the strings are equal, false otherwise. Because it's not - * possible to include spaces in strings passed in via the boot-args, a period in the logname will - * match a space in the zone name. - */ + zindex = zone_index_from_ptr(addr); + other = &zone_array[zindex]; + if (zindex >= os_atomic_load(&num_zones, relaxed) || !other->z_self) { + panic("zone_require failed: invalid zone index %d " + "(addr: %p, expected: %s%s)", zindex, + addr, zone_heap_name(zone), zone->z_name); + } else { + panic("zone_require failed: address in unexpected zone id %d (%s%s) " + "(addr: %p, expected: %s%s)", + zindex, zone_heap_name(other), other->z_name, + addr, zone_heap_name(zone), zone->z_name); + } +} -static int -log_this_zone(const char *zonename, const char *logname) +__abortlike +static void +zone_id_require_panic(zone_id_t zid, void *addr) { - int len; - const char *zc = zonename; - const char *lc = logname; + zone_require_panic(&zone_array[zid], addr); +} - /* - * Compare the strings. We bound the compare by MAX_ZONE_NAME. - */ +/* + * Routines to panic if a pointer is not mapped to an expected zone. + * This can be used as a means of pinning an object to the zone it is expected + * to be a part of. Causes a panic if the address does not belong to any + * specified zone, does not belong to any zone, has been freed and therefore + * unmapped from the zone, or the pointer contains an uninitialized value that + * does not belong to any zone. + * + * Note that this can only work with collectable zones without foreign pages. + */ +void +zone_require(zone_t zone, void *addr) +{ + vm_size_t esize = zone_elem_size(zone); - for (len = 1; len <= MAX_ZONE_NAME; zc++, lc++, len++) { + if (__probable(from_zone_map(addr, esize, ZONE_ADDR_NATIVE))) { + if (zone_has_index(zone, zone_index_from_ptr(addr))) { + return; + } +#if CONFIG_GZALLOC + } else if (__probable(zone->gzalloc_tracked)) { + return; +#endif + } + zone_require_panic(zone, addr); +} - /* - * If the current characters don't match, check for a space in - * in the zone name and a corresponding period in the log name. - * If that's not there, then the strings don't match. - */ +void +zone_id_require(zone_id_t zid, vm_size_t esize, void *addr) +{ + if (__probable(from_zone_map(addr, esize, ZONE_ADDR_NATIVE))) { + if (zid == zone_index_from_ptr(addr)) { + return; + } +#if CONFIG_GZALLOC + } else if (__probable(zone_array[zid].gzalloc_tracked)) { + return; +#endif + } + zone_id_require_panic(zid, addr); +} - if (*zc != *lc && !(*zc == ' ' && *lc == '.')) - break; +void +zone_id_require_allow_foreign(zone_id_t zid, vm_size_t esize, void *addr) +{ + if (__probable(from_zone_map(addr, esize, ZONE_ADDR_NATIVE) || + from_zone_map(addr, esize, ZONE_ADDR_FOREIGN))) { + if (zid == zone_index_from_ptr(addr)) { + return; + } +#if CONFIG_GZALLOC + } else if (__probable(zone_array[zid].gzalloc_tracked)) { + return; +#endif + } + zone_id_require_panic(zid, addr); +} - /* - * The strings are equal so far. If we're at the end, then it's a match. - */ +bool +zone_owns(zone_t zone, void *addr) +{ + vm_size_t esize = zone_elem_size(zone); - if (*zc == '\0') - return TRUE; + if (__probable(from_zone_map(addr, esize, ZONE_ADDR_NATIVE))) { + return zone_has_index(zone, zone_index_from_ptr(addr)); +#if CONFIG_GZALLOC + } else if (__probable(zone->gzalloc_tracked)) { + return true; +#endif } - - return FALSE; + return false; } +#endif /* !ZALLOC_TEST */ +#pragma mark Zone bits allocator -/* - * Test if we want to log this zalloc/zfree event. We log if this is the zone we're interested in and - * the buffer for the records has been allocated. +/*! + * @defgroup Zone Bitmap allocator + * @{ + * + * @brief + * Functions implementing the zone bitmap allocator + * + * @discussion + * The zone allocator maintains which elements are allocated or free in bitmaps. + * + * When the number of elements per page is smaller than 32, it is stored inline + * on the @c zone_page_metadata structure (@c zm_inline_bitmap is set, + * and @c zm_bitmap used for storage). + * + * When the number of elements is larger, then a bitmap is allocated from + * a buddy allocator (impelemented under the @c zba_* namespace). Pointers + * to bitmaps are implemented as a packed 32 bit bitmap reference, stored in + * @c zm_bitmap. The low 3 bits encode the scale (order) of the allocation in + * @c ZBA_GRANULE units, and hence actual allocations encoded with that scheme + * cannot be larger than 1024 bytes (8192 bits). + * + * This buddy allocator can actually accomodate allocations as large + * as 8k on 16k systems and 2k on 4k systems. + * + * Note: @c zba_* functions are implementation details not meant to be used + * outside of the allocation of the allocator itself. Interfaces to the rest of + * the zone allocator are documented and not @c zba_* prefixed. */ -#define DO_LOGGING(z) (z->zone_logging == TRUE && z->zlog_btlog) +#define ZBA_CHUNK_SIZE PAGE_MAX_SIZE +#define ZBA_GRANULE sizeof(uint64_t) +#define ZBA_GRANULE_BITS (8 * sizeof(uint64_t)) +#define ZBA_MAX_ORDER (PAGE_MAX_SHIFT - 4) +#define ZBA_MAX_ALLOC_ORDER 7 +#define ZBA_SLOTS (ZBA_CHUNK_SIZE / ZBA_GRANULE) +static_assert(2ul * ZBA_GRANULE << ZBA_MAX_ORDER == ZBA_CHUNK_SIZE, "chunk sizes"); +static_assert(ZBA_MAX_ALLOC_ORDER <= ZBA_MAX_ORDER, "ZBA_MAX_ORDER is enough"); + +struct zone_bits_chain { + uint32_t zbc_next; + uint32_t zbc_prev; +} __attribute__((aligned(ZBA_GRANULE))); + +struct zone_bits_head { + uint32_t zbh_next; + uint32_t zbh_unused; +} __attribute__((aligned(ZBA_GRANULE))); + +static_assert(sizeof(struct zone_bits_chain) == ZBA_GRANULE, "zbc size"); +static_assert(sizeof(struct zone_bits_head) == ZBA_GRANULE, "zbh size"); + +struct zone_bits_allocator_meta { + uint32_t zbam_chunks; + uint32_t __zbam_padding; + struct zone_bits_head zbam_lists[ZBA_MAX_ORDER + 1]; +}; -extern boolean_t kmem_alloc_ready; +struct zone_bits_allocator_header { + uint64_t zbah_bits[ZBA_SLOTS / (8 * sizeof(uint64_t))]; +}; -#if CONFIG_ZLEAKS -#pragma mark - -#pragma mark Zone Leak Detection +#if ZALLOC_TEST +static struct zalloc_bits_allocator_test_setup { + vm_offset_t zbats_base; + void (*zbats_populate)(vm_address_t addr, vm_size_t size); +} zba_test_info; -/* - * The zone leak detector, abbreviated 'zleak', keeps track of a subset of the currently outstanding - * allocations made by the zone allocator. Every zleak_sample_factor allocations in each zone, we capture a - * backtrace. Every free, we examine the table and determine if the allocation was being tracked, - * and stop tracking it if it was being tracked. - * - * We track the allocations in the zallocations hash table, which stores the address that was returned from - * the zone allocator. Each stored entry in the zallocations table points to an entry in the ztraces table, which - * stores the backtrace associated with that allocation. This provides uniquing for the relatively large - * backtraces - we don't store them more than once. - * - * Data collection begins when the zone map is 50% full, and only occurs for zones that are taking up - * a large amount of virtual space. - */ -#define ZLEAK_STATE_ENABLED 0x01 /* Zone leak monitoring should be turned on if zone_map fills up. */ -#define ZLEAK_STATE_ACTIVE 0x02 /* We are actively collecting traces. */ -#define ZLEAK_STATE_ACTIVATING 0x04 /* Some thread is doing setup; others should move along. */ -#define ZLEAK_STATE_FAILED 0x08 /* Attempt to allocate tables failed. We will not try again. */ -uint32_t zleak_state = 0; /* State of collection, as above */ +static struct zone_bits_allocator_header * +zba_base_header(void) +{ + return (struct zone_bits_allocator_header *)zba_test_info.zbats_base; +} -boolean_t panic_include_ztrace = FALSE; /* Enable zleak logging on panic */ -vm_size_t zleak_global_tracking_threshold; /* Size of zone map at which to start collecting data */ -vm_size_t zleak_per_zone_tracking_threshold; /* Size a zone will have before we will collect data on it */ -unsigned int zleak_sample_factor = 1000; /* Allocations per sample attempt */ +static void +zba_populate(uint32_t n) +{ + vm_address_t base = zba_test_info.zbats_base; + zba_test_info.zbats_populate(base + n * ZBA_CHUNK_SIZE, ZBA_CHUNK_SIZE); +} +#else +__startup_data +static uint8_t zba_chunk_startup[ZBA_CHUNK_SIZE] +__attribute__((aligned(ZBA_CHUNK_SIZE))); +static LCK_MTX_EARLY_DECLARE(zba_mtx, &zone_locks_grp); -/* - * Counters for allocation statistics. - */ +static struct zone_bits_allocator_header * +zba_base_header(void) +{ + return (struct zone_bits_allocator_header *)zone_info.zi_bits_range.min_address; +} -/* Times two active records want to occupy the same spot */ -unsigned int z_alloc_collisions = 0; -unsigned int z_trace_collisions = 0; +static void +zba_lock(void) +{ + lck_mtx_lock(&zba_mtx); +} -/* Times a new record lands on a spot previously occupied by a freed allocation */ -unsigned int z_alloc_overwrites = 0; -unsigned int z_trace_overwrites = 0; +static void +zba_unlock(void) +{ + lck_mtx_unlock(&zba_mtx); +} -/* Times a new alloc or trace is put into the hash table */ -unsigned int z_alloc_recorded = 0; -unsigned int z_trace_recorded = 0; +static void +zba_populate(uint32_t n) +{ + vm_size_t size = ZBA_CHUNK_SIZE; + vm_address_t addr; + + addr = zone_info.zi_bits_range.min_address + n * size; + if (addr >= zone_info.zi_bits_range.max_address) { + zone_t z = zone_find_largest(); + panic("zba_populate: out of bitmap space, " + "likely due to memory leak in zone [%s%s] " + "(%luM, %d elements allocated)", + zone_heap_name(z), zone_name(z), + (unsigned long)zone_size_wired(z) >> 20, + zone_count_allocated(z)); + } -/* Times zleak_log returned false due to not being able to acquire the lock */ -unsigned int z_total_conflicts = 0; + for (;;) { + kern_return_t kr = KERN_SUCCESS; + if (0 == pmap_find_phys(kernel_pmap, addr)) { + kr = kernel_memory_populate(kernel_map, addr, size, + KMA_NOPAGEWAIT | KMA_KOBJECT | KMA_ZERO, + VM_KERN_MEMORY_OSFMK); + } -#pragma mark struct zallocation -/* - * Structure for keeping track of an allocation - * An allocation bucket is in use if its element is not NULL - */ -struct zallocation { - uintptr_t za_element; /* the element that was zalloc'ed or zfree'ed, NULL if bucket unused */ - vm_size_t za_size; /* how much memory did this allocation take up? */ - uint32_t za_trace_index; /* index into ztraces for backtrace associated with allocation */ - /* TODO: #if this out */ - uint32_t za_hit_count; /* for determining effectiveness of hash function */ -}; + if (kr == KERN_SUCCESS) { + return; + } -/* Size must be a power of two for the zhash to be able to just mask off bits instead of mod */ -uint32_t zleak_alloc_buckets = CONFIG_ZLEAK_ALLOCATION_MAP_NUM; -uint32_t zleak_trace_buckets = CONFIG_ZLEAK_TRACE_MAP_NUM; + zba_unlock(); + VM_PAGE_WAIT(); + zba_lock(); + } +} +#endif -vm_size_t zleak_max_zonemap_size; +__pure2 +static struct zone_bits_allocator_meta * +zba_meta(void) +{ + return (struct zone_bits_allocator_meta *)&zba_base_header()[1]; +} -/* Hashmaps of allocations and their corresponding traces */ -static struct zallocation* zallocations; -static struct ztrace* ztraces; +__pure2 +static uint64_t * +zba_slot_base(void) +{ + return (uint64_t *)zba_base_header(); +} -/* not static so that panic can see this, see kern/debug.c */ -struct ztrace* top_ztrace; +__pure2 +static vm_address_t +zba_page_addr(uint32_t n) +{ + return (vm_address_t)zba_base_header() + n * ZBA_CHUNK_SIZE; +} -/* Lock to protect zallocations, ztraces, and top_ztrace from concurrent modification. */ -static lck_spin_t zleak_lock; -static lck_attr_t zleak_lock_attr; -static lck_grp_t zleak_lock_grp; -static lck_grp_attr_t zleak_lock_grp_attr; +__pure2 +static struct zone_bits_head * +zba_head(uint32_t order) +{ + return &zba_meta()->zbam_lists[order]; +} -/* - * Initializes the zone leak monitor. Called from zone_init() - */ -static void -zleak_init(vm_size_t max_zonemap_size) +__pure2 +static uint32_t +zba_head_index(uint32_t order) { - char scratch_buf[16]; - boolean_t zleak_enable_flag = FALSE; + uint32_t hdr_size = sizeof(struct zone_bits_allocator_header) + + offsetof(struct zone_bits_allocator_meta, zbam_lists); + return (hdr_size / ZBA_GRANULE) + order; +} - zleak_max_zonemap_size = max_zonemap_size; - zleak_global_tracking_threshold = max_zonemap_size / 2; - zleak_per_zone_tracking_threshold = zleak_global_tracking_threshold / 8; +__pure2 +static struct zone_bits_chain * +zba_chain_for_index(uint32_t index) +{ + return (struct zone_bits_chain *)(zba_slot_base() + index); +} - /* -zleakoff (flag to disable zone leak monitor) */ - if (PE_parse_boot_argn("-zleakoff", scratch_buf, sizeof(scratch_buf))) { - zleak_enable_flag = FALSE; - printf("zone leak detection disabled\n"); - } else { - zleak_enable_flag = TRUE; - printf("zone leak detection enabled\n"); - } - - /* zfactor=XXXX (override how often to sample the zone allocator) */ - if (PE_parse_boot_argn("zfactor", &zleak_sample_factor, sizeof(zleak_sample_factor))) { - printf("Zone leak factor override: %u\n", zleak_sample_factor); - } +__pure2 +static uint32_t +zba_chain_to_index(const struct zone_bits_chain *zbc) +{ + return (uint32_t)((const uint64_t *)zbc - zba_slot_base()); +} - /* zleak-allocs=XXXX (override number of buckets in zallocations) */ - if (PE_parse_boot_argn("zleak-allocs", &zleak_alloc_buckets, sizeof(zleak_alloc_buckets))) { - printf("Zone leak alloc buckets override: %u\n", zleak_alloc_buckets); - /* uses 'is power of 2' trick: (0x01000 & 0x00FFF == 0) */ - if (zleak_alloc_buckets == 0 || (zleak_alloc_buckets & (zleak_alloc_buckets-1))) { - printf("Override isn't a power of two, bad things might happen!\n"); +__abortlike +static void +zba_head_corruption_panic(uint32_t order) +{ + panic("zone bits allocator head[%d:%p] is corrupt", order, + zba_head(order)); +} + +__abortlike +static void +zba_chain_corruption_panic(struct zone_bits_chain *a, struct zone_bits_chain *b) +{ + panic("zone bits allocator freelist is corrupt (%p <-> %p)", a, b); +} + +static void +zba_push_block(struct zone_bits_chain *zbc, uint32_t order) +{ + struct zone_bits_head *hd = zba_head(order); + uint32_t hd_index = zba_head_index(order); + uint32_t index = zba_chain_to_index(zbc); + struct zone_bits_chain *next; + + if (hd->zbh_next) { + next = zba_chain_for_index(hd->zbh_next); + if (next->zbc_prev != hd_index) { + zba_head_corruption_panic(order); } + next->zbc_prev = index; } - - /* zleak-traces=XXXX (override number of buckets in ztraces) */ - if (PE_parse_boot_argn("zleak-traces", &zleak_trace_buckets, sizeof(zleak_trace_buckets))) { - printf("Zone leak trace buckets override: %u\n", zleak_trace_buckets); - /* uses 'is power of 2' trick: (0x01000 & 0x00FFF == 0) */ - if (zleak_trace_buckets == 0 || (zleak_trace_buckets & (zleak_trace_buckets-1))) { - printf("Override isn't a power of two, bad things might happen!\n"); + zbc->zbc_next = hd->zbh_next; + zbc->zbc_prev = hd_index; + hd->zbh_next = index; +} + +static void +zba_remove_block(struct zone_bits_chain *zbc) +{ + struct zone_bits_chain *prev = zba_chain_for_index(zbc->zbc_prev); + uint32_t index = zba_chain_to_index(zbc); + + if (prev->zbc_next != index) { + zba_chain_corruption_panic(prev, zbc); + } + if ((prev->zbc_next = zbc->zbc_next)) { + struct zone_bits_chain *next = zba_chain_for_index(zbc->zbc_next); + if (next->zbc_prev != index) { + zba_chain_corruption_panic(zbc, next); } + next->zbc_prev = zbc->zbc_prev; } - - /* allocate the zleak_lock */ - lck_grp_attr_setdefault(&zleak_lock_grp_attr); - lck_grp_init(&zleak_lock_grp, "zleak_lock", &zleak_lock_grp_attr); - lck_attr_setdefault(&zleak_lock_attr); - lck_spin_init(&zleak_lock, &zleak_lock_grp, &zleak_lock_attr); - - if (zleak_enable_flag) { - zleak_state = ZLEAK_STATE_ENABLED; +} + +static vm_address_t +zba_try_pop_block(uint32_t order) +{ + struct zone_bits_head *hd = zba_head(order); + struct zone_bits_chain *zbc; + + if (hd->zbh_next == 0) { + return 0; } + + zbc = zba_chain_for_index(hd->zbh_next); + zba_remove_block(zbc); + return (vm_address_t)zbc; } -#if CONFIG_ZLEAKS +static struct zone_bits_allocator_header * +zba_header(vm_offset_t addr) +{ + addr &= -(vm_offset_t)ZBA_CHUNK_SIZE; + return (struct zone_bits_allocator_header *)addr; +} -/* - * Support for kern.zleak.active sysctl - a simplified - * version of the zleak_state variable. - */ -int -get_zleak_state(void) +static size_t +zba_node_parent(size_t node) { - if (zleak_state & ZLEAK_STATE_FAILED) - return (-1); - if (zleak_state & ZLEAK_STATE_ACTIVE) - return (1); - return (0); + return (node - 1) / 2; } -#endif +static size_t +zba_node_left_child(size_t node) +{ + return node * 2 + 1; +} +static size_t +zba_node_buddy(size_t node) +{ + return ((node - 1) ^ 1) + 1; +} -kern_return_t -zleak_activate(void) +static size_t +zba_node(vm_offset_t addr, uint32_t order) { - kern_return_t retval; - vm_size_t z_alloc_size = zleak_alloc_buckets * sizeof(struct zallocation); - vm_size_t z_trace_size = zleak_trace_buckets * sizeof(struct ztrace); - void *allocations_ptr = NULL; - void *traces_ptr = NULL; + vm_offset_t offs = (addr % ZBA_CHUNK_SIZE) / ZBA_GRANULE; + return (offs >> order) + (1 << (ZBA_MAX_ORDER - order + 1)) - 1; +} - /* Only one thread attempts to activate at a time */ - if (zleak_state & (ZLEAK_STATE_ACTIVE | ZLEAK_STATE_ACTIVATING | ZLEAK_STATE_FAILED)) { - return KERN_SUCCESS; - } +static struct zone_bits_chain * +zba_chain_for_node(struct zone_bits_allocator_header *zbah, size_t node, uint32_t order) +{ + vm_offset_t offs = (node - (1 << (ZBA_MAX_ORDER - order + 1)) + 1) << order; + return (struct zone_bits_chain *)((vm_offset_t)zbah + offs * ZBA_GRANULE); +} - /* Indicate that we're doing the setup */ - lck_spin_lock(&zleak_lock); - if (zleak_state & (ZLEAK_STATE_ACTIVE | ZLEAK_STATE_ACTIVATING | ZLEAK_STATE_FAILED)) { - lck_spin_unlock(&zleak_lock); - return KERN_SUCCESS; +static void +zba_node_flip_split(struct zone_bits_allocator_header *zbah, size_t node) +{ + zbah->zbah_bits[node / 64] ^= 1ull << (node % 64); +} + +static bool +zba_node_is_split(struct zone_bits_allocator_header *zbah, size_t node) +{ + return zbah->zbah_bits[node / 64] & (1ull << (node % 64)); +} + +static void +zba_free(vm_offset_t addr, uint32_t order) +{ + struct zone_bits_allocator_header *zbah = zba_header(addr); + struct zone_bits_chain *zbc; + size_t node = zba_node(addr, order); + + while (node) { + size_t parent = zba_node_parent(node); + + zba_node_flip_split(zbah, parent); + if (zba_node_is_split(zbah, parent)) { + break; + } + + zbc = zba_chain_for_node(zbah, zba_node_buddy(node), order); + zba_remove_block(zbc); + order++; + node = parent; } - zleak_state |= ZLEAK_STATE_ACTIVATING; - lck_spin_unlock(&zleak_lock); + zba_push_block(zba_chain_for_node(zbah, node, order), order); +} - /* Allocate and zero tables */ - retval = kmem_alloc_kobject(kernel_map, (vm_offset_t*)&allocations_ptr, z_alloc_size, VM_KERN_MEMORY_OSFMK); - if (retval != KERN_SUCCESS) { - goto fail; +static vm_size_t +zba_chunk_header_size(uint32_t n) +{ + vm_size_t hdr_size = sizeof(struct zone_bits_allocator_header); + if (n == 0) { + hdr_size += sizeof(struct zone_bits_allocator_meta); } + return hdr_size; +} - retval = kmem_alloc_kobject(kernel_map, (vm_offset_t*)&traces_ptr, z_trace_size, VM_KERN_MEMORY_OSFMK); - if (retval != KERN_SUCCESS) { - goto fail; +static void +zba_init_chunk(uint32_t n) +{ + vm_size_t hdr_size = zba_chunk_header_size(n); + vm_offset_t page = zba_page_addr(n); + struct zone_bits_allocator_header *zbah = zba_header(page); + vm_size_t size = ZBA_CHUNK_SIZE; + size_t node; + + for (uint32_t o = ZBA_MAX_ORDER + 1; o-- > 0;) { + if (size < hdr_size + (ZBA_GRANULE << o)) { + continue; + } + size -= ZBA_GRANULE << o; + node = zba_node(page + size, o); + zba_node_flip_split(zbah, zba_node_parent(node)); + zba_push_block(zba_chain_for_node(zbah, node, o), o); } - bzero(allocations_ptr, z_alloc_size); - bzero(traces_ptr, z_trace_size); + zba_meta()->zbam_chunks = n + 1; +} - /* Everything's set. Install tables, mark active. */ - zallocations = allocations_ptr; - ztraces = traces_ptr; +__attribute__((noinline)) +static void +zba_grow(void) +{ + uint32_t chunk = zba_meta()->zbam_chunks; - /* - * Initialize the top_ztrace to the first entry in ztraces, - * so we don't have to check for null in zleak_log - */ - top_ztrace = &ztraces[0]; + zba_populate(chunk); + if (zba_meta()->zbam_chunks == chunk) { + zba_init_chunk(chunk); + } +} - /* - * Note that we do need a barrier between installing - * the tables and setting the active flag, because the zfree() - * path accesses the table without a lock if we're active. - */ - lck_spin_lock(&zleak_lock); - zleak_state |= ZLEAK_STATE_ACTIVE; - zleak_state &= ~ZLEAK_STATE_ACTIVATING; - lck_spin_unlock(&zleak_lock); - - return 0; +static vm_offset_t +zba_alloc(uint32_t order) +{ + struct zone_bits_allocator_header *zbah; + uint32_t cur = order; + vm_address_t addr; + size_t node; + + while ((addr = zba_try_pop_block(cur)) == 0) { + if (cur++ >= ZBA_MAX_ORDER) { + zba_grow(); + cur = order; + } + } -fail: - /* - * If we fail to allocate memory, don't further tax - * the system by trying again. - */ - lck_spin_lock(&zleak_lock); - zleak_state |= ZLEAK_STATE_FAILED; - zleak_state &= ~ZLEAK_STATE_ACTIVATING; - lck_spin_unlock(&zleak_lock); + zbah = zba_header(addr); + node = zba_node(addr, cur); + zba_node_flip_split(zbah, zba_node_parent(node)); + while (cur > order) { + cur--; + zba_node_flip_split(zbah, node); + node = zba_node_left_child(node); + zba_push_block(zba_chain_for_node(zbah, node + 1, cur), cur); + } - if (allocations_ptr != NULL) { - kmem_free(kernel_map, (vm_offset_t)allocations_ptr, z_alloc_size); + return addr; +} + +#define zba_map_index(type, n) (n / (8 * sizeof(type))) +#define zba_map_bit(type, n) ((type)1 << (n % (8 * sizeof(type)))) +#define zba_map_mask_lt(type, n) (zba_map_bit(type, n) - 1) +#define zba_map_mask_ge(type, n) ((type)-zba_map_bit(type, n)) + +#if !ZALLOC_TEST +static uint32_t +zba_bits_ref_order(uint32_t bref) +{ + return bref & 0x7; +} + +static bitmap_t * +zba_bits_ref_ptr(uint32_t bref) +{ + return zba_slot_base() + (bref >> 3); +} + +static vm_offset_t +zba_scan_bitmap_inline(zone_t zone, struct zone_page_metadata *meta, + vm_offset_t eidx) +{ + size_t i = eidx / 32; + uint32_t map; + + if (eidx % 32) { + map = meta[i].zm_bitmap & zba_map_mask_ge(uint32_t, eidx); + if (map) { + eidx = __builtin_ctz(map); + meta[i].zm_bitmap ^= 1u << eidx; + return i * 32 + eidx; + } + i++; } - if (traces_ptr != NULL) { - kmem_free(kernel_map, (vm_offset_t)traces_ptr, z_trace_size); + uint32_t chunk_len = meta->zm_chunk_len; + if (chunk_len == 1 && zone->z_percpu) { + chunk_len = zpercpu_count(); + } + for (int j = 0; j < chunk_len; j++, i++) { + if (i >= chunk_len) { + i = 0; + } + if (__probable(map = meta[i].zm_bitmap)) { + meta[i].zm_bitmap &= map - 1; + return i * 32 + __builtin_ctz(map); + } } - return retval; + zone_page_meta_accounting_panic(zone, meta, "zm_bitmap"); } -/* - * TODO: What about allocations that never get deallocated, - * especially ones with unique backtraces? Should we wait to record - * until after boot has completed? - * (How many persistent zallocs are there?) +static vm_offset_t +zba_scan_bitmap_ref(zone_t zone, struct zone_page_metadata *meta, + vm_offset_t eidx) +{ + uint32_t bits_size = 1 << zba_bits_ref_order(meta->zm_bitmap); + bitmap_t *bits = zba_bits_ref_ptr(meta->zm_bitmap); + size_t i = eidx / 64; + uint64_t map; + + if (eidx % 64) { + map = bits[i] & zba_map_mask_ge(uint64_t, eidx); + if (map) { + eidx = __builtin_ctzll(map); + bits[i] ^= 1ull << eidx; + return i * 64 + eidx; + } + i++; + } + + for (int j = 0; j < bits_size; i++, j++) { + if (i >= bits_size) { + i = 0; + } + if (__probable(map = bits[i])) { + bits[i] &= map - 1; + return i * 64 + __builtin_ctzll(map); + } + } + + zone_page_meta_accounting_panic(zone, meta, "zm_bitmap"); +} + +/*! + * @function zone_meta_find_and_clear_bit + * + * @brief + * The core of the bitmap allocator: find a bit set in the bitmaps. + * + * @discussion + * This method will round robin through available allocations, + * with a per-core memory of the last allocated element index allocated. + * + * This is done in order to avoid a fully LIFO behavior which makes exploiting + * double-free bugs way too practical. + * + * @param zone The zone we're allocating from. + * @param meta The main metadata for the chunk being allocated from. */ +static vm_offset_t +zone_meta_find_and_clear_bit(zone_t zone, struct zone_page_metadata *meta) +{ + zone_stats_t zs = zpercpu_get(zone->z_stats); + vm_offset_t eidx = zs->zs_alloc_rr + 1; -/* - * This function records the allocation in the allocations table, - * and stores the associated backtrace in the traces table - * (or just increments the refcount if the trace is already recorded) - * If the allocation slot is in use, the old allocation is replaced with the new allocation, and - * the associated trace's refcount is decremented. - * If the trace slot is in use, it returns. - * The refcount is incremented by the amount of memory the allocation consumes. - * The return value indicates whether to try again next time. + if (meta->zm_inline_bitmap) { + eidx = zba_scan_bitmap_inline(zone, meta, eidx); + } else { + eidx = zba_scan_bitmap_ref(zone, meta, eidx); + } + zs->zs_alloc_rr = (uint16_t)eidx; + return eidx; +} + +/*! + * @function zone_meta_bits_init + * + * @brief + * Initializes the zm_bitmap field(s) for a newly assigned chunk. + * + * @param meta The main metadata for the initialized chunk. + * @param count The number of elements the chunk can hold + * (which might be partial for partially populated chunks). + * @param nbits The maximum nuber of bits that will be used. */ -static boolean_t -zleak_log(uintptr_t* bt, - uintptr_t addr, - uint32_t depth, - vm_size_t allocation_size) +static void +zone_meta_bits_init(struct zone_page_metadata *meta, + uint32_t count, uint32_t nbits) { - /* Quit if there's someone else modifying the hash tables */ - if (!lck_spin_try_lock(&zleak_lock)) { - z_total_conflicts++; - return FALSE; + static_assert(ZONE_MAX_ALLOC_SIZE / ZONE_MIN_ELEM_SIZE <= + ZBA_GRANULE_BITS << ZBA_MAX_ORDER, "bitmaps will be large enough"); + + if (meta->zm_inline_bitmap) { + /* + * We're called with the metadata zm_bitmap fields already + * zeroed out. + */ + for (size_t i = 0; 32 * i < count; i++) { + if (32 * i + 32 <= count) { + meta[i].zm_bitmap = ~0u; + } else { + meta[i].zm_bitmap = zba_map_mask_lt(uint32_t, count); + } + } + } else { + uint32_t order = flsll((nbits - 1) / ZBA_GRANULE_BITS); + uint64_t *bits; + + assert(order <= ZBA_MAX_ALLOC_ORDER); + assert(count <= ZBA_GRANULE_BITS << order); + + zba_lock(); + bits = (uint64_t *)zba_alloc(order); + zba_unlock(); + + for (size_t i = 0; i < 1u << order; i++) { + if (64 * i + 64 <= count) { + bits[i] = ~0ull; + } else if (64 * i < count) { + bits[i] = zba_map_mask_lt(uint64_t, count); + } else { + bits[i] = 0ull; + } + } + + meta->zm_bitmap = (uint32_t)((vm_offset_t)bits - + (vm_offset_t)zba_slot_base()) + order; } - - struct zallocation* allocation = &zallocations[hashaddr(addr, zleak_alloc_buckets)]; - - uint32_t trace_index = hashbacktrace(bt, depth, zleak_trace_buckets); - struct ztrace* trace = &ztraces[trace_index]; - - allocation->za_hit_count++; - trace->zt_hit_count++; - - /* - * If the allocation bucket we want to be in is occupied, and if the occupier - * has the same trace as us, just bail. - */ - if (allocation->za_element != (uintptr_t) 0 && trace_index == allocation->za_trace_index) { - z_alloc_collisions++; - - lck_spin_unlock(&zleak_lock); - return TRUE; +} + +/*! + * @function zone_meta_bits_merge + * + * @brief + * Adds elements [start, end) to a chunk being extended. + * + * @param meta The main metadata for the extended chunk. + * @param start The index of the first element to add to the chunk. + * @param end The index of the last (exclusive) element to add. + */ +static void +zone_meta_bits_merge(struct zone_page_metadata *meta, + uint32_t start, uint32_t end) +{ + if (meta->zm_inline_bitmap) { + while (start < end) { + size_t s_i = start / 32; + size_t s_e = end / 32; + + if (s_i == s_e) { + meta[s_i].zm_bitmap |= zba_map_mask_lt(uint32_t, end) & + zba_map_mask_ge(uint32_t, start); + break; + } + + meta[s_i].zm_bitmap |= zba_map_mask_ge(uint32_t, start); + start += 32 - (start % 32); + } + } else { + uint64_t *bits = zba_bits_ref_ptr(meta->zm_bitmap); + + while (start < end) { + size_t s_i = start / 64; + size_t s_e = end / 64; + + if (s_i == s_e) { + bits[s_i] |= zba_map_mask_lt(uint64_t, end) & + zba_map_mask_ge(uint64_t, start); + break; + } + bits[s_i] |= zba_map_mask_ge(uint64_t, start); + start += 64 - (start % 64); + } } - - /* STEP 1: Store the backtrace in the traces array. */ - /* A size of zero indicates that the trace bucket is free. */ - - if (trace->zt_size > 0 && bcmp(trace->zt_stack, bt, (depth * sizeof(uintptr_t))) != 0 ) { - /* - * Different unique trace with same hash! - * Just bail - if we're trying to record the leaker, hopefully the other trace will be deallocated - * and get out of the way for later chances - */ - trace->zt_collisions++; - z_trace_collisions++; - - lck_spin_unlock(&zleak_lock); - return TRUE; - } else if (trace->zt_size > 0) { - /* Same trace, already added, so increment refcount */ - trace->zt_size += allocation_size; +} + +/*! + * @function zone_bits_free + * + * @brief + * Frees a bitmap to the zone bitmap allocator. + * + * @param bref + * A bitmap reference set by @c zone_meta_bits_init() in a @c zm_bitmap field. + */ +static void +zone_bits_free(uint32_t bref) +{ + zba_lock(); + zba_free((vm_offset_t)zba_bits_ref_ptr(bref), zba_bits_ref_order(bref)); + zba_unlock(); +} + +/*! + * @function zone_meta_is_free + * + * @brief + * Returns whether a given element appears free. + */ +static bool +zone_meta_is_free(struct zone_page_metadata *meta, zone_element_t ze) +{ + vm_offset_t eidx = zone_element_idx(ze); + if (meta->zm_inline_bitmap) { + uint32_t bit = zba_map_bit(uint32_t, eidx); + return meta[zba_map_index(uint32_t, eidx)].zm_bitmap & bit; } else { - /* Found an unused trace bucket, record the trace here! */ - if (trace->zt_depth != 0) /* if this slot was previously used but not currently in use */ - z_trace_overwrites++; - - z_trace_recorded++; - trace->zt_size = allocation_size; - memcpy(trace->zt_stack, bt, (depth * sizeof(uintptr_t)) ); - - trace->zt_depth = depth; - trace->zt_collisions = 0; + bitmap_t *bits = zba_bits_ref_ptr(meta->zm_bitmap); + uint64_t bit = zba_map_bit(uint64_t, eidx); + return bits[zba_map_index(uint64_t, eidx)] & bit; } - - /* STEP 2: Store the allocation record in the allocations array. */ - - if (allocation->za_element != (uintptr_t) 0) { - /* - * Straight up replace any allocation record that was there. We don't want to do the work - * to preserve the allocation entries that were there, because we only record a subset of the - * allocations anyways. - */ - - z_alloc_collisions++; - - struct ztrace* associated_trace = &ztraces[allocation->za_trace_index]; - /* Knock off old allocation's size, not the new allocation */ - associated_trace->zt_size -= allocation->za_size; - } else if (allocation->za_trace_index != 0) { - /* Slot previously used but not currently in use */ - z_alloc_overwrites++; +} + +/*! + * @function zone_meta_mark_free + * + * @brief + * Marks an element as free and returns whether it was marked as used. + */ +static bool +zone_meta_mark_free(struct zone_page_metadata *meta, zone_element_t ze) +{ + vm_offset_t eidx = zone_element_idx(ze); + + if (meta->zm_inline_bitmap) { + uint32_t bit = zba_map_bit(uint32_t, eidx); + if (meta[zba_map_index(uint32_t, eidx)].zm_bitmap & bit) { + return false; + } + meta[zba_map_index(uint32_t, eidx)].zm_bitmap ^= bit; + } else { + bitmap_t *bits = zba_bits_ref_ptr(meta->zm_bitmap); + uint64_t bit = zba_map_bit(uint64_t, eidx); + if (bits[zba_map_index(uint64_t, eidx)] & bit) { + return false; + } + bits[zba_map_index(uint64_t, eidx)] ^= bit; } + return true; +} - allocation->za_element = addr; - allocation->za_trace_index = trace_index; - allocation->za_size = allocation_size; - - z_alloc_recorded++; - - if (top_ztrace->zt_size < trace->zt_size) - top_ztrace = trace; - - lck_spin_unlock(&zleak_lock); - return TRUE; +/*! + * @function zone_meta_mark_used + * + * @brief + * Marks an element as used and returns whether it was marked as free + */ +static bool +zone_meta_mark_used(struct zone_page_metadata *meta, zone_element_t ze) +{ + vm_offset_t eidx = zone_element_idx(ze); + + if (meta->zm_inline_bitmap) { + uint32_t bit = zba_map_bit(uint32_t, eidx); + if (meta[zba_map_index(uint32_t, eidx)].zm_bitmap & bit) { + meta[zba_map_index(uint32_t, eidx)].zm_bitmap ^= bit; + return true; + } + } else { + bitmap_t *bits = zba_bits_ref_ptr(meta->zm_bitmap); + uint64_t bit = zba_map_bit(uint64_t, eidx); + if (bits[zba_map_index(uint64_t, eidx)] & bit) { + bits[zba_map_index(uint64_t, eidx)] ^= bit; + return true; + } + } + return false; } +#endif /* !ZALLOC_TEST */ +/*! @} */ +#pragma mark ZTAGS +#if !ZALLOC_TEST +#if VM_MAX_TAG_ZONES /* - * Free the allocation record and release the stacktrace. - * This should be as fast as possible because it will be called for every free. + * Zone tagging allows for per "tag" accounting of allocations for the kalloc + * zones only. + * + * There are 3 kinds of tags that can be used: + * - pre-registered VM_KERN_MEMORY_* + * - dynamic tags allocated per call sites in core-kernel (using vm_tag_alloc()) + * - per-kext tags computed by IOKit (using the magic VM_TAG_BT marker). + * + * The VM tracks the statistics in lazily allocated structures. + * See vm_tag_will_update_zone(), vm_tag_update_zone_size(). + * + * If for some reason the requested tag cannot be accounted for, + * the tag is forced to VM_KERN_MEMORY_KALLOC which is pre-allocated. + * + * Each allocated element also remembers the tag it was assigned, + * in its ztSlot() which lets zalloc/zfree update statistics correctly. */ + +// for zones with tagging enabled: + +// calculate a pointer to the tag base entry, +// holding either a uint32_t the first tag offset for a page in the zone map, +// or two uint16_t tags if the page can only hold one or two elements + +#define ZTAGBASE(zone, element) \ + (&((uint32_t *)zone_tagbase_min)[atop((element) - \ + zone_info.zi_map_range[ZONE_ADDR_NATIVE].min_address)]) + +static vm_offset_t zone_tagbase_min; +static vm_offset_t zone_tagbase_max; +static vm_offset_t zone_tagbase_map_size; +static vm_map_t zone_tagbase_map; + +static vm_offset_t zone_tags_min; +static vm_offset_t zone_tags_max; +static vm_offset_t zone_tags_map_size; +static vm_map_t zone_tags_map; + +// simple heap allocator for allocating the tags for new memory + +static LCK_MTX_EARLY_DECLARE(ztLock, &zone_locks_grp); /* heap lock */ + +enum{ + ztFreeIndexCount = 8, + ztFreeIndexMax = (ztFreeIndexCount - 1), + ztTagsPerBlock = 4 +}; + +struct ztBlock { +#if __LITTLE_ENDIAN__ + uint64_t free:1, + next:21, + prev:21, + size:21; +#else +// ztBlock needs free bit least significant +#error !__LITTLE_ENDIAN__ +#endif +}; +typedef struct ztBlock ztBlock; + +static ztBlock * ztBlocks; +static uint32_t ztBlocksCount; +static uint32_t ztBlocksFree; + +static uint32_t +ztLog2up(uint32_t size) +{ + if (1 == size) { + size = 0; + } else { + size = 32 - __builtin_clz(size - 1); + } + return size; +} + +// pointer to the tag for an element +static vm_tag_t * +ztSlot(zone_t zone, vm_offset_t element) +{ + vm_tag_t *result; + if (zone->tags_inline) { + result = (vm_tag_t *)ZTAGBASE(zone, element); + if ((PAGE_MASK & element) >= zone_elem_size(zone)) { + result++; + } + } else { + result = &((vm_tag_t *)zone_tags_min)[ZTAGBASE(zone, element)[0] + + (element & PAGE_MASK) / zone_elem_size(zone)]; + } + return result; +} + +static uint32_t +ztLog2down(uint32_t size) +{ + size = 31 - __builtin_clz(size); + return size; +} + static void -zleak_free(uintptr_t addr, - vm_size_t allocation_size) +ztFault(vm_map_t map, const void * address, size_t size, uint32_t flags) { - if (addr == (uintptr_t) 0) - return; - - struct zallocation* allocation = &zallocations[hashaddr(addr, zleak_alloc_buckets)]; - - /* Double-checked locking: check to find out if we're interested, lock, check to make - * sure it hasn't changed, then modify it, and release the lock. - */ - - if (allocation->za_element == addr && allocation->za_trace_index < zleak_trace_buckets) { - /* if the allocation was the one, grab the lock, check again, then delete it */ - lck_spin_lock(&zleak_lock); - - if (allocation->za_element == addr && allocation->za_trace_index < zleak_trace_buckets) { - struct ztrace *trace; + vm_map_offset_t addr = (vm_map_offset_t) address; + vm_map_offset_t page, end; + + page = trunc_page(addr); + end = round_page(addr + size); + + for (; page < end; page += page_size) { + if (!pmap_find_phys(kernel_pmap, page)) { + kern_return_t __unused + ret = kernel_memory_populate(map, page, PAGE_SIZE, + KMA_KOBJECT | flags, VM_KERN_MEMORY_DIAG); + assert(ret == KERN_SUCCESS); + } + } +} - /* allocation_size had better match what was passed into zleak_log - otherwise someone is freeing into the wrong zone! */ - if (allocation->za_size != allocation_size) { - panic("Freeing as size %lu memory that was allocated with size %lu\n", - (uintptr_t)allocation_size, (uintptr_t)allocation->za_size); +static boolean_t +ztPresent(const void * address, size_t size) +{ + vm_map_offset_t addr = (vm_map_offset_t) address; + vm_map_offset_t page, end; + boolean_t result; + + page = trunc_page(addr); + end = round_page(addr + size); + for (result = TRUE; (page < end); page += page_size) { + result = pmap_find_phys(kernel_pmap, page); + if (!result) { + break; + } + } + return result; +} + + +void __unused +ztDump(boolean_t sanity); +void __unused +ztDump(boolean_t sanity) +{ + uint32_t q, cq, p; + + for (q = 0; q <= ztFreeIndexMax; q++) { + p = q; + do{ + if (sanity) { + cq = ztLog2down(ztBlocks[p].size); + if (cq > ztFreeIndexMax) { + cq = ztFreeIndexMax; + } + if (!ztBlocks[p].free + || ((p != q) && (q != cq)) + || (ztBlocks[ztBlocks[p].next].prev != p) + || (ztBlocks[ztBlocks[p].prev].next != p)) { + kprintf("zterror at %d", p); + ztDump(FALSE); + kprintf("zterror at %d", p); + assert(FALSE); + } + continue; } - - trace = &ztraces[allocation->za_trace_index]; - - /* size of 0 indicates trace bucket is unused */ - if (trace->zt_size > 0) { - trace->zt_size -= allocation_size; + kprintf("zt[%03d]%c %d, %d, %d\n", + p, ztBlocks[p].free ? 'F' : 'A', + ztBlocks[p].next, ztBlocks[p].prev, + ztBlocks[p].size); + p = ztBlocks[p].next; + if (p == q) { + break; } - - /* A NULL element means the allocation bucket is unused */ - allocation->za_element = 0; + }while (p != q); + if (!sanity) { + printf("\n"); } - lck_spin_unlock(&zleak_lock); } + if (!sanity) { + printf("-----------------------\n"); + } +} + + + +#define ZTBDEQ(idx) \ + ztBlocks[ztBlocks[(idx)].prev].next = ztBlocks[(idx)].next; \ + ztBlocks[ztBlocks[(idx)].next].prev = ztBlocks[(idx)].prev; + +static void +ztFree(zone_t zone __unused, uint32_t index, uint32_t count) +{ + uint32_t q, w, p, size, merge; + + assert(count); + ztBlocksFree += count; + + // merge with preceding + merge = (index + count); + if ((merge < ztBlocksCount) + && ztPresent(&ztBlocks[merge], sizeof(ztBlocks[merge])) + && ztBlocks[merge].free) { + ZTBDEQ(merge); + count += ztBlocks[merge].size; + } + + // merge with following + merge = (index - 1); + if ((merge > ztFreeIndexMax) + && ztPresent(&ztBlocks[merge], sizeof(ztBlocks[merge])) + && ztBlocks[merge].free) { + size = ztBlocks[merge].size; + count += size; + index -= size; + ZTBDEQ(index); + } + + q = ztLog2down(count); + if (q > ztFreeIndexMax) { + q = ztFreeIndexMax; + } + w = q; + // queue in order of size + while (TRUE) { + p = ztBlocks[w].next; + if (p == q) { + break; + } + if (ztBlocks[p].size >= count) { + break; + } + w = p; + } + ztBlocks[p].prev = index; + ztBlocks[w].next = index; + + // fault in first + ztFault(zone_tags_map, &ztBlocks[index], sizeof(ztBlocks[index]), 0); + + // mark first & last with free flag and size + ztBlocks[index].free = TRUE; + ztBlocks[index].size = count; + ztBlocks[index].prev = w; + ztBlocks[index].next = p; + if (count > 1) { + index += (count - 1); + // fault in last + ztFault(zone_tags_map, &ztBlocks[index], sizeof(ztBlocks[index]), 0); + ztBlocks[index].free = TRUE; + ztBlocks[index].size = count; + } +} + +static uint32_t +ztAlloc(zone_t zone, uint32_t count) +{ + uint32_t q, w, p, leftover; + + assert(count); + + q = ztLog2up(count); + if (q > ztFreeIndexMax) { + q = ztFreeIndexMax; + } + do{ + w = q; + while (TRUE) { + p = ztBlocks[w].next; + if (p == q) { + break; + } + if (ztBlocks[p].size >= count) { + // dequeue, mark both ends allocated + ztBlocks[w].next = ztBlocks[p].next; + ztBlocks[ztBlocks[p].next].prev = w; + ztBlocks[p].free = FALSE; + ztBlocksFree -= ztBlocks[p].size; + if (ztBlocks[p].size > 1) { + ztBlocks[p + ztBlocks[p].size - 1].free = FALSE; + } + + // fault all the allocation + ztFault(zone_tags_map, &ztBlocks[p], count * sizeof(ztBlocks[p]), 0); + // mark last as allocated + if (count > 1) { + ztBlocks[p + count - 1].free = FALSE; + } + // free remainder + leftover = ztBlocks[p].size - count; + if (leftover) { + ztFree(zone, p + ztBlocks[p].size - leftover, leftover); + } + + return p; + } + w = p; + } + q++; + }while (q <= ztFreeIndexMax); + + return -1U; +} + +__startup_func +static void +zone_tagging_init(vm_size_t max_zonemap_size) +{ + kern_return_t ret; + vm_map_kernel_flags_t vmk_flags; + uint32_t idx; + + // allocate submaps VM_KERN_MEMORY_DIAG + + zone_tagbase_map_size = atop(max_zonemap_size) * sizeof(uint32_t); + vmk_flags = VM_MAP_KERNEL_FLAGS_NONE; + vmk_flags.vmkf_permanent = TRUE; + ret = kmem_suballoc(kernel_map, &zone_tagbase_min, zone_tagbase_map_size, + FALSE, VM_FLAGS_ANYWHERE, vmk_flags, VM_KERN_MEMORY_DIAG, + &zone_tagbase_map); + + if (ret != KERN_SUCCESS) { + panic("zone_init: kmem_suballoc failed"); + } + zone_tagbase_max = zone_tagbase_min + round_page(zone_tagbase_map_size); + + zone_tags_map_size = 2048 * 1024 * sizeof(vm_tag_t); + vmk_flags = VM_MAP_KERNEL_FLAGS_NONE; + vmk_flags.vmkf_permanent = TRUE; + ret = kmem_suballoc(kernel_map, &zone_tags_min, zone_tags_map_size, + FALSE, VM_FLAGS_ANYWHERE, vmk_flags, VM_KERN_MEMORY_DIAG, + &zone_tags_map); + + if (ret != KERN_SUCCESS) { + panic("zone_init: kmem_suballoc failed"); + } + zone_tags_max = zone_tags_min + round_page(zone_tags_map_size); + + ztBlocks = (ztBlock *) zone_tags_min; + ztBlocksCount = (uint32_t)(zone_tags_map_size / sizeof(ztBlock)); + + // initialize the qheads + lck_mtx_lock(&ztLock); + + ztFault(zone_tags_map, &ztBlocks[0], sizeof(ztBlocks[0]), 0); + for (idx = 0; idx < ztFreeIndexCount; idx++) { + ztBlocks[idx].free = TRUE; + ztBlocks[idx].next = idx; + ztBlocks[idx].prev = idx; + ztBlocks[idx].size = 0; + } + // free remaining space + ztFree(NULL, ztFreeIndexCount, ztBlocksCount - ztFreeIndexCount); + + lck_mtx_unlock(&ztLock); +} + +static void +ztMemoryAdd(zone_t zone, vm_offset_t mem, vm_size_t size) +{ + uint32_t * tagbase; + uint32_t count, block, blocks, idx; + size_t pages; + + pages = atop(size); + tagbase = ZTAGBASE(zone, mem); + + lck_mtx_lock(&ztLock); + + // fault tagbase + ztFault(zone_tagbase_map, tagbase, pages * sizeof(uint32_t), 0); + + if (!zone->tags_inline) { + // allocate tags + count = (uint32_t)(size / zone_elem_size(zone)); + blocks = ((count + ztTagsPerBlock - 1) / ztTagsPerBlock); + block = ztAlloc(zone, blocks); + if (-1U == block) { + ztDump(false); + } + assert(-1U != block); + } + + lck_mtx_unlock(&ztLock); + + if (!zone->tags_inline) { + // set tag base for each page + block *= ztTagsPerBlock; + for (idx = 0; idx < pages; idx++) { + vm_offset_t esize = zone_elem_size(zone); + tagbase[idx] = block + (uint32_t)((ptoa(idx) + esize - 1) / esize); + } + } +} + +static void +ztMemoryRemove(zone_t zone, vm_offset_t mem, vm_size_t size) +{ + uint32_t * tagbase; + uint32_t count, block, blocks, idx; + size_t pages; + + // set tag base for each page + pages = atop(size); + tagbase = ZTAGBASE(zone, mem); + block = tagbase[0]; + for (idx = 0; idx < pages; idx++) { + tagbase[idx] = 0xFFFFFFFF; + } + + lck_mtx_lock(&ztLock); + if (!zone->tags_inline) { + count = (uint32_t)(size / zone_elem_size(zone)); + blocks = ((count + ztTagsPerBlock - 1) / ztTagsPerBlock); + assert(block != 0xFFFFFFFF); + block /= ztTagsPerBlock; + ztFree(NULL /* zone is unlocked */, block, blocks); + } + + lck_mtx_unlock(&ztLock); +} + +uint32_t +zone_index_from_tag_index(uint32_t tag_zone_index, vm_size_t * elem_size) +{ + simple_lock(&all_zones_lock, &zone_locks_grp); + + zone_index_foreach(idx) { + zone_t z = &zone_array[idx]; + if (!z->tags) { + continue; + } + if (tag_zone_index != z->tag_zone_index) { + continue; + } + + *elem_size = zone_elem_size(z); + simple_unlock(&all_zones_lock); + return idx; + } + + simple_unlock(&all_zones_lock); + + return -1U; +} + +#endif /* VM_MAX_TAG_ZONES */ +#endif /* !ZALLOC_TEST */ +#pragma mark zalloc helpers +#if !ZALLOC_TEST + +__pure2 +static inline uint16_t +zc_mag_size(void) +{ + return zc_magazine_size; +} + +__attribute__((noinline, cold)) +static void +zone_lock_was_contended(zone_t zone, zone_cache_t zc) +{ + lck_spin_lock_nopreempt(&zone->z_lock); + + /* + * If zone caching has been disabled due to memory pressure, + * then recording contention is not useful, give the system + * time to recover. + */ + if (__improbable(zone_caching_disabled)) { + return; + } + + zone->z_contention_cur++; + + if (zc == NULL || zc->zc_depot_max >= INT16_MAX * zc_mag_size()) { + return; + } + + /* + * Let the depot grow based on how bad the contention is, + * and how populated the zone is. + */ + if (zone->z_contention_wma < 2 * Z_CONTENTION_WMA_UNIT) { + if (zc->zc_depot_max * zpercpu_count() * 20u >= + zone->z_elems_avail) { + return; + } + } + if (zone->z_contention_wma < 4 * Z_CONTENTION_WMA_UNIT) { + if (zc->zc_depot_max * zpercpu_count() * 10u >= + zone->z_elems_avail) { + return; + } + } + if (!zc_grow_threshold || zone->z_contention_wma < + zc_grow_threshold * Z_CONTENTION_WMA_UNIT) { + return; + } + + zc->zc_depot_max++; +} + +static inline void +zone_lock_nopreempt_check_contention(zone_t zone, zone_cache_t zc) +{ + if (lck_spin_try_lock_nopreempt(&zone->z_lock)) { + return; + } + + zone_lock_was_contended(zone, zc); +} + +static inline void +zone_lock_check_contention(zone_t zone, zone_cache_t zc) +{ + disable_preemption(); + zone_lock_nopreempt_check_contention(zone, zc); +} + +static inline void +zone_unlock_nopreempt(zone_t zone) +{ + lck_spin_unlock_nopreempt(&zone->z_lock); +} + +static inline void +zone_depot_lock_nopreempt(zone_cache_t zc) +{ + hw_lock_bit_nopreempt(&zc->zc_depot_lock, 0, &zone_locks_grp); +} + +static inline void +zone_depot_unlock_nopreempt(zone_cache_t zc) +{ + hw_unlock_bit_nopreempt(&zc->zc_depot_lock, 0); +} + +static inline void +zone_depot_lock(zone_cache_t zc) +{ + hw_lock_bit(&zc->zc_depot_lock, 0, &zone_locks_grp); +} + +static inline void +zone_depot_unlock(zone_cache_t zc) +{ + hw_unlock_bit(&zc->zc_depot_lock, 0); +} + +const char * +zone_name(zone_t z) +{ + return z->z_name; +} + +const char * +zone_heap_name(zone_t z) +{ + if (__probable(z->kalloc_heap < KHEAP_ID_COUNT)) { + return kalloc_heap_names[z->kalloc_heap]; + } + return "invalid"; +} + +static uint32_t +zone_alloc_pages_for_nelems(zone_t z, vm_size_t max_elems) +{ + vm_size_t elem_count, chunks; + + elem_count = ptoa(z->z_percpu ? 1 : z->z_chunk_pages) / zone_elem_size(z); + chunks = (max_elems + elem_count - 1) / elem_count; + + return (uint32_t)MIN(UINT32_MAX, chunks * z->z_chunk_pages); +} + +static inline vm_size_t +zone_submaps_approx_size(void) +{ + vm_size_t size = 0; + + for (unsigned idx = 0; idx <= zone_last_submap_idx; idx++) { + size += zone_submaps[idx]->size; + } + + return size; +} + +static void +zone_cache_swap_magazines(zone_cache_t cache) +{ + uint16_t count_a = cache->zc_alloc_cur; + uint16_t count_f = cache->zc_free_cur; + zone_element_t *elems_a = cache->zc_alloc_elems; + zone_element_t *elems_f = cache->zc_free_elems; + + z_debug_assert(count_a <= zc_mag_size()); + z_debug_assert(count_f <= zc_mag_size()); + + cache->zc_alloc_cur = count_f; + cache->zc_free_cur = count_a; + cache->zc_alloc_elems = elems_f; + cache->zc_free_elems = elems_a; +} + +/*! + * @function zone_magazine_load + * + * @brief + * Cache the value of @c zm_cur on the cache to avoid a dependent load + * on the allocation fastpath. + */ +static void +zone_magazine_load(uint16_t *count, zone_element_t **elems, zone_magazine_t mag) +{ + z_debug_assert(mag->zm_cur <= zc_mag_size()); + *count = mag->zm_cur; + *elems = mag->zm_elems; +} + +/*! + * @function zone_magazine_replace + * + * @brief + * Unlod a magazine and load a new one instead. + */ +static zone_magazine_t +zone_magazine_replace(uint16_t *count, zone_element_t **elems, + zone_magazine_t mag) +{ + zone_magazine_t old; + + old = (zone_magazine_t)((uintptr_t)*elems - + offsetof(struct zone_magazine, zm_elems)); + old->zm_cur = *count; + z_debug_assert(old->zm_cur <= zc_mag_size()); + zone_magazine_load(count, elems, mag); + + return old; +} + +static zone_magazine_t +zone_magazine_alloc(zalloc_flags_t flags) +{ + return zalloc_ext(zc_magazine_zone, zc_magazine_zone->z_stats, + flags | Z_ZERO); +} + +static void +zone_magazine_free(zone_magazine_t mag) +{ + zfree_ext(zc_magazine_zone, zc_magazine_zone->z_stats, mag); +} + +static void +zone_enable_caching(zone_t zone) +{ + zone_cache_t caches; + + caches = zalloc_percpu_permanent_type(struct zone_cache); + zpercpu_foreach(zc, caches) { + zone_magazine_load(&zc->zc_alloc_cur, &zc->zc_alloc_elems, + zone_magazine_alloc(Z_WAITOK | Z_NOFAIL)); + zone_magazine_load(&zc->zc_free_cur, &zc->zc_free_elems, + zone_magazine_alloc(Z_WAITOK | Z_NOFAIL)); + STAILQ_INIT(&zc->zc_depot); + } + + if (os_atomic_xchg(&zone->z_pcpu_cache, caches, release)) { + panic("allocating caches for zone %s twice", zone->z_name); + } +} + +bool +zone_maps_owned(vm_address_t addr, vm_size_t size) +{ + return from_zone_map(addr, size, ZONE_ADDR_NATIVE); +} + +void +zone_map_sizes( + vm_map_size_t *psize, + vm_map_size_t *pfree, + vm_map_size_t *plargest_free) +{ + vm_map_size_t size, free, largest; + + vm_map_sizes(zone_submaps[0], psize, pfree, plargest_free); + + for (uint32_t i = 1; i <= zone_last_submap_idx; i++) { + vm_map_sizes(zone_submaps[i], &size, &free, &largest); + *psize += size; + *pfree += free; + *plargest_free = MAX(*plargest_free, largest); + } +} + +__attribute__((always_inline)) +vm_map_t +zone_submap(zone_t zone) +{ + return zone_submaps[zone->z_submap_idx]; +} + +unsigned +zpercpu_count(void) +{ + return zpercpu_early_count; +} + +int +track_this_zone(const char *zonename, const char *logname) +{ + unsigned int len; + const char *zc = zonename; + const char *lc = logname; + + /* + * Compare the strings. We bound the compare by MAX_ZONE_NAME. + */ + + for (len = 1; len <= MAX_ZONE_NAME; zc++, lc++, len++) { + /* + * If the current characters don't match, check for a space in + * in the zone name and a corresponding period in the log name. + * If that's not there, then the strings don't match. + */ + + if (*zc != *lc && !(*zc == ' ' && *lc == '.')) { + break; + } + + /* + * The strings are equal so far. If we're at the end, then it's a match. + */ + + if (*zc == '\0') { + return TRUE; + } + } + + return FALSE; +} + +#if DEBUG || DEVELOPMENT + +vm_size_t +zone_element_info(void *addr, vm_tag_t * ptag) +{ + vm_size_t size = 0; + vm_tag_t tag = VM_KERN_MEMORY_NONE; + struct zone *src_zone; + + if (from_zone_map(addr, sizeof(void *), ZONE_ADDR_NATIVE) || + from_zone_map(addr, sizeof(void *), ZONE_ADDR_FOREIGN)) { + src_zone = &zone_array[zone_index_from_ptr(addr)]; +#if VM_MAX_TAG_ZONES + if (__improbable(src_zone->tags)) { + tag = *ztSlot(src_zone, (vm_offset_t)addr) >> 1; + } +#endif /* VM_MAX_TAG_ZONES */ + size = zone_elem_size(src_zone); + } else { +#if CONFIG_GZALLOC + gzalloc_element_size(addr, NULL, &size); +#endif /* CONFIG_GZALLOC */ + } + *ptag = tag; + return size; +} + +#endif /* DEBUG || DEVELOPMENT */ + +/* The backup pointer is stored in the last pointer-sized location in an element. */ +__header_always_inline vm_offset_t * +get_primary_ptr(vm_offset_t elem) +{ + return (vm_offset_t *)elem; +} + +__header_always_inline vm_offset_t * +get_backup_ptr(vm_offset_t elem, vm_size_t elem_size) +{ + return (vm_offset_t *)(elem + elem_size - sizeof(vm_offset_t)); +} + +#endif /* !ZALLOC_TEST */ +#pragma mark Zone poisoning/zeroing and early random +#if !ZALLOC_TEST + +#define ZONE_ENTROPY_CNT 2 +static struct zone_bool_gen { + struct bool_gen zbg_bg; + uint32_t zbg_entropy[ZONE_ENTROPY_CNT]; +} zone_bool_gen[MAX_CPUS]; + +/* + * Initialize zone poisoning + * called from zone_bootstrap before any allocations are made from zalloc + */ +__startup_func +static void +zp_bootstrap(void) +{ + char temp_buf[16]; + + /* + * Initialize canary random cookie. + * + * Make sure that (zp_canary ^ pointer) have non zero low bits (01) + * different from ZONE_POISON (11). + * + * On LP64, have (zp_canary ^ pointer) have the high bits equal 0xC0FFEE... + */ + static_assert(ZONE_POISON % 4 == 3); + zp_canary = (uintptr_t)early_random(); +#if __LP64__ + zp_canary &= 0x000000fffffffffc; + zp_canary |= 0xc0ffee0000000001 ^ 0xffffff0000000000; +#else + zp_canary &= 0xfffffffc; + zp_canary |= 0x00000001; +#endif + + /* -zp: enable poisoning for every alloc and free */ + if (PE_parse_boot_argn("-zp", temp_buf, sizeof(temp_buf))) { + zp_factor = 1; + } + + /* -no-zp: disable poisoning */ + if (PE_parse_boot_argn("-no-zp", temp_buf, sizeof(temp_buf))) { + zp_factor = 0; + printf("Zone poisoning disabled\n"); + } + + zpercpu_foreach_cpu(cpu) { + random_bool_init(&zone_bool_gen[cpu].zbg_bg); + } +} + +static inline uint32_t +zone_poison_count_init(zone_t zone) +{ + return zp_factor + (((uint32_t)zone_elem_size(zone)) >> zp_scale) ^ + (mach_absolute_time() & 0x7); +} + +/* + * Zero the element if zone has z_free_zeroes flag set else poison + * the element if zs_poison_seqno hits 0. + */ +static zprot_mode_t +zfree_clear_or_poison(zone_t zone, vm_offset_t addr, vm_offset_t elem_size) +{ + if (zone->z_free_zeroes) { + if (zone->z_percpu) { + zpercpu_foreach_cpu(i) { + bzero((void *)(addr + ptoa(i)), elem_size); + } + } else { + bzero((void *)addr, elem_size); + } + return ZPM_ZERO; + } + + zprot_mode_t poison = ZPM_AUTO; +#if ZALLOC_ENABLE_POISONING + if (__improbable(zp_factor == 1)) { + poison = ZPM_POISON; + } else if (__probable(zp_factor != 0)) { + uint32_t *seqnop = &zpercpu_get(zone->z_stats)->zs_poison_seqno; + uint32_t seqno = os_atomic_load(seqnop, relaxed); + if (seqno == 0) { + os_atomic_store(seqnop, zone_poison_count_init(zone), relaxed); + poison = ZPM_POISON; + } else { + os_atomic_store(seqnop, seqno - 1, relaxed); + } + } + if (poison == ZPM_POISON) { + /* memset_pattern{4|8} could help make this faster: */ + for (size_t i = 0; i < elem_size / sizeof(vm_offset_t); i++) { + ((vm_offset_t *)addr)[i] = ZONE_POISON; + } + } else { + /* + * Set a canary at the extremities. + * + * Zero first zp_min_size bytes of elements that aren't being + * poisoned. + * + * Element size is larger than zp_min_size in this path, + * zones with smaller elements have z_free_zeroes set. + */ + *get_primary_ptr(addr) = zp_canary ^ (uintptr_t)addr; + bzero((void *)addr + sizeof(vm_offset_t), + zp_min_size - sizeof(vm_offset_t)); + *get_backup_ptr(addr, elem_size) = zp_canary ^ (uintptr_t)addr; + + poison = ZPM_CANARY; + } +#endif /* ZALLOC_ENABLE_POISONING */ + + return poison; +} + +#if ZALLOC_ENABLE_POISONING + +__abortlike +static void +zalloc_uaf_panic(zone_t z, uintptr_t elem, size_t size, zprot_mode_t zpm) +{ + uint32_t esize = (uint32_t)zone_elem_size(z); + uint32_t first_offs = ~0u; + uintptr_t first_bits = 0, v; + char buf[1024]; + int pos = 0; + const char *how; + +#if __LP64__ +#define ZPF "0x%016lx" +#else +#define ZPF "0x%08lx" +#endif + + buf[0] = '\0'; + + if (zpm == ZPM_CANARY) { + how = "canaries"; + + v = *get_primary_ptr(elem); + if (v != (elem ^ zp_canary)) { + pos += scnprintf(buf + pos, sizeof(buf) - pos, "\n" + "%5d: got "ZPF", want "ZPF" (xor: "ZPF")", + 0, v, (elem ^ zp_canary), (v ^ elem ^ zp_canary)); + if (first_offs > 0) { + first_offs = 0; + first_bits = v; + } + } + + v = *get_backup_ptr(elem, esize); + if (v != (elem ^ zp_canary)) { + pos += scnprintf(buf + pos, sizeof(buf) - pos, "\n" + "%5d: got "ZPF", want "ZPF" (xor: "ZPF")", + esize - (int)sizeof(v), v, (elem ^ zp_canary), + (v ^ elem ^ zp_canary)); + if (first_offs > esize - sizeof(v)) { + first_offs = esize - sizeof(v); + first_bits = v; + } + } + + for (uint32_t o = sizeof(v); o < zp_min_size; o += sizeof(v)) { + if ((v = *(uintptr_t *)(elem + o)) == 0) { + continue; + } + pos += scnprintf(buf + pos, sizeof(buf) - pos, "\n" + "%5d: "ZPF, o, v); + if (first_offs > o) { + first_offs = o; + first_bits = v; + } + } + } else if (zpm == ZPM_ZERO) { + how = "zero"; + + for (uint32_t o = 0; o < size; o += sizeof(v)) { + if ((v = *(uintptr_t *)(elem + o)) == 0) { + continue; + } + pos += scnprintf(buf + pos, sizeof(buf) - pos, "\n" + "%5d: "ZPF, o, v); + if (first_offs > o) { + first_offs = o; + first_bits = v; + } + } + } else { + how = "poison"; + + for (uint32_t o = 0; o < size; o += sizeof(v)) { + if ((v = *(uintptr_t *)(elem + o)) == ZONE_POISON) { + continue; + } + pos += scnprintf(buf + pos, sizeof(buf) - pos, "\n" + "%5d: "ZPF" (xor: "ZPF")", + o, v, (v ^ ZONE_POISON)); + if (first_offs > o) { + first_offs = o; + first_bits = v; + } + } + } + + (panic)("[%s%s]: element modified after free " + "(off:%d, val:"ZPF", sz:%d, ptr:%p, prot:%s)%s", + zone_heap_name(z), zone_name(z), + first_offs, first_bits, esize, (void *)elem, how, buf); + +#undef ZPF +} + +static void +zalloc_validate_element_zero(zone_t zone, vm_offset_t elem, vm_size_t size) +{ + if (memcmp_zero_ptr_aligned((void *)elem, size)) { + zalloc_uaf_panic(zone, elem, size, ZPM_ZERO); + } + if (!zone->z_percpu) { + return; + } + for (size_t i = zpercpu_count(); --i > 0;) { + elem += PAGE_SIZE; + if (memcmp_zero_ptr_aligned((void *)elem, size)) { + zalloc_uaf_panic(zone, elem, size, ZPM_ZERO); + } + } +} + +#if __arm64__ || __arm__ +typedef __attribute__((ext_vector_type(2))) vm_offset_t zpair_t; +#else +typedef struct { + vm_offset_t x; + vm_offset_t y; +} zpair_t; +#endif + + +__attribute__((noinline)) +static void +zalloc_validate_element_poison(zone_t zone, vm_offset_t elem, vm_size_t size) +{ + vm_offset_t p = elem; + vm_offset_t end = elem + size; + + const zpair_t poison = { ZONE_POISON, ZONE_POISON }; + zpair_t a, b; + + a.x = *(const vm_offset_t *)p; + a.y = *(const vm_offset_t *)(end - sizeof(vm_offset_t)); + + a.x ^= poison.x; + a.y ^= poison.y; + + /* + * align p to the next double-wide boundary + * align end to the previous double-wide boundary + */ + p = (p + sizeof(zpair_t) - 1) & -sizeof(zpair_t); + end &= -sizeof(zpair_t); + + if ((end - p) % (2 * sizeof(zpair_t)) == 0) { + b.y = 0; + b.y = 0; + } else { + end -= sizeof(zpair_t); + b.x = ((zpair_t *)end)[0].x ^ poison.x; + b.y = ((zpair_t *)end)[0].y ^ poison.y; + } + + for (; p < end; p += 2 * sizeof(zpair_t)) { + a.x |= ((zpair_t *)p)[0].x ^ poison.x; + a.y |= ((zpair_t *)p)[0].y ^ poison.y; + b.x |= ((zpair_t *)p)[1].x ^ poison.x; + b.y |= ((zpair_t *)p)[1].y ^ poison.y; + } + + a.x |= b.x; + a.y |= b.y; + + if (a.x || a.y) { + zalloc_uaf_panic(zone, elem, size, ZPM_POISON); + } +} + +static void +zalloc_validate_element(zone_t zone, vm_offset_t elem, vm_size_t size, + zprot_mode_t zpm) +{ + vm_offset_t *primary = get_primary_ptr(elem); + vm_offset_t *backup = get_backup_ptr(elem, size); + +#if CONFIG_GZALLOC + if (zone->gzalloc_tracked) { + return; + } +#endif /* CONFIG_GZALLOC */ + + if (zone->z_free_zeroes) { + return zalloc_validate_element_zero(zone, elem, size); + } + + switch (zpm) { + case ZPM_AUTO: + if (*backup == 0) { + size -= sizeof(vm_size_t); + return zalloc_validate_element_zero(zone, elem, size); + } + if (*backup == ZONE_POISON) { + size -= sizeof(vm_size_t); + return zalloc_validate_element_poison(zone, elem, size); + } + OS_FALLTHROUGH; + + case ZPM_CANARY: + if ((*primary ^ zp_canary) != elem || (*backup ^ zp_canary) != elem) { + zalloc_uaf_panic(zone, elem, size, ZPM_CANARY); + } + *primary = *backup = 0; + size = zp_min_size; + OS_FALLTHROUGH; + + case ZPM_ZERO: + return zalloc_validate_element_zero(zone, elem, size); + + case ZPM_POISON: + return zalloc_validate_element_poison(zone, elem, size); + } +} + +#endif /* ZALLOC_ENABLE_POISONING */ +#if ZALLOC_EARLY_GAPS + +__attribute__((noinline)) +static void +zone_early_gap_drop(int n) +{ + while (n-- > 0) { + zone_t zone0 = &zone_array[0]; + struct zone_page_metadata *meta = NULL; + vm_offset_t addr; + uint16_t pages; + vm_map_t map; + + lck_mtx_lock(&zone_metadata_region_lck); + + if (!zone_pva_is_null(zone0->z_pageq_va)) { + meta = zone_meta_queue_pop_native(zone0, + &zone0->z_pageq_va, &addr); + map = zone_submaps[meta->zm_chunk_len]; + pages = meta->zm_alloc_size; + __builtin_bzero(meta, sizeof(struct zone_page_metadata)); + } + + lck_mtx_unlock(&zone_metadata_region_lck); + + if (!meta) { + break; + } + + kmem_free(map, addr, ptoa(pages)); + } +} + +static void +zone_early_gap_add(zone_t z, uint16_t pages) +{ + struct zone_page_metadata *meta = NULL; + zone_t zone0 = &zone_array[0]; + kern_return_t kr; + vm_offset_t addr; + + kma_flags_t kmaflags = KMA_KOBJECT | KMA_ZERO | KMA_VAONLY; + if (z->z_submap_idx == Z_SUBMAP_IDX_GENERAL && + z->kalloc_heap != KHEAP_ID_NONE) { + kmaflags |= KMA_KHEAP; + } + + kr = kernel_memory_allocate(zone_submap(z), &addr, ptoa(pages), 0, + kmaflags, VM_KERN_MEMORY_ZONE); + + if (kr != KERN_SUCCESS) { + panic("unable to allocate early gap (%d pages): %d", pages, kr); + } + + zone_meta_populate(addr, ptoa(pages)); + + meta = zone_meta_from_addr(addr); + meta->zm_alloc_size = pages; + meta->zm_chunk_len = z->z_submap_idx; + + lck_mtx_lock(&zone_metadata_region_lck); + zone_meta_queue_push(zone0, &zone0->z_pageq_va, meta); + lck_mtx_unlock(&zone_metadata_region_lck); +} + +/* + * Roughly until pd1 is made, introduce random gaps + * between allocated pages. + * + * This way the early boot allocations are not in a completely + * predictible order and relative position. + * + * Those gaps are returned to the maps afterwards. + * + * We abuse the zone 0 (which is unused) "va" pageq to remember + * those ranges. + */ +__attribute__((noinline)) +static void +zone_allocate_random_early_gap(zone_t z) +{ + int16_t pages = early_random() % 16; + + /* + * 6% of the time: drop 2 gaps + * 25% of the time: drop 1 gap + * 37% of the time: do nothing + * 18% of the time: add 1 gap + * 12% of the time: add 2 gaps + */ + if (pages > 10) { + zone_early_gap_drop(pages == 15 ? 2 : 1); + } + if (pages < 5) { + /* values are 6 through 16 */ + zone_early_gap_add(z, 6 + 2 * pages); + } + if (pages < 2) { + zone_early_gap_add(z, 6 + early_random() % 16); + } +} + +static inline void +zone_cleanup_early_gaps_if_needed(void) +{ + if (__improbable(!zone_pva_is_null(zone_array[0].z_pageq_va))) { + zone_early_gap_drop(10); + } +} + +#endif /* ZALLOC_EARLY_GAPS */ + +static void +zone_early_scramble_rr(zone_t zone, zone_stats_t zstats) +{ + int cpu = cpu_number(); + zone_stats_t zs = zpercpu_get_cpu(zstats, cpu); + uint32_t bits; + + bits = random_bool_gen_bits(&zone_bool_gen[cpu].zbg_bg, + zone_bool_gen[cpu].zbg_entropy, ZONE_ENTROPY_CNT, 8); + + zs->zs_alloc_rr += bits; + zs->zs_alloc_rr %= zone->z_chunk_elems; +} + +#endif /* !ZALLOC_TEST */ +#pragma mark Zone Leak Detection +#if !ZALLOC_TEST + +/* + * Zone leak debugging code + * + * When enabled, this code keeps a log to track allocations to a particular zone that have not + * yet been freed. Examining this log will reveal the source of a zone leak. The log is allocated + * only when logging is enabled, so there is no effect on the system when it's turned off. Logging is + * off by default. + * + * Enable the logging via the boot-args. Add the parameter "zlog=" to boot-args where + * is the name of the zone you wish to log. + * + * This code only tracks one zone, so you need to identify which one is leaking first. + * Generally, you'll know you have a leak when you get a "zalloc retry failed 3" panic from the zone + * garbage collector. Note that the zone name printed in the panic message is not necessarily the one + * containing the leak. So do a zprint from gdb and locate the zone with the bloated size. This + * is most likely the problem zone, so set zlog in boot-args to this zone name, reboot and re-run the test. The + * next time it panics with this message, examine the log using the kgmacros zstack, findoldest and countpcs. + * See the help in the kgmacros for usage info. + * + * + * Zone corruption logging + * + * Logging can also be used to help identify the source of a zone corruption. First, identify the zone + * that is being corrupted, then add "-zc zlog=" to the boot-args. When -zc is used in conjunction + * with zlog, it changes the logging style to track both allocations and frees to the zone. So when the + * corruption is detected, examining the log will show you the stack traces of the callers who last allocated + * and freed any particular element in the zone. Use the findelem kgmacro with the address of the element that's been + * corrupted to examine its history. This should lead to the source of the corruption. + */ + +/* Returns TRUE if we rolled over the counter at factor */ +__header_always_inline bool +sample_counter(volatile uint32_t *count_p, uint32_t factor) +{ + uint32_t old_count, new_count = 0; + if (count_p != NULL) { + os_atomic_rmw_loop(count_p, old_count, new_count, relaxed, { + new_count = old_count + 1; + if (new_count >= factor) { + new_count = 0; + } + }); + } + + return new_count == 0; +} + +#if ZONE_ENABLE_LOGGING +/* Log allocations and frees to help debug a zone element corruption */ +static TUNABLE(bool, corruption_debug_flag, "-zc", false); + +#define MAX_NUM_ZONES_ALLOWED_LOGGING 10 /* Maximum 10 zones can be logged at once */ + +static int max_num_zones_to_log = MAX_NUM_ZONES_ALLOWED_LOGGING; +static int num_zones_logged = 0; + +/* + * The number of records in the log is configurable via the zrecs parameter in boot-args. Set this to + * the number of records you want in the log. For example, "zrecs=10" sets it to 10 records. Since this + * is the number of stacks suspected of leaking, we don't need many records. + */ + +#if defined(__LP64__) +#define ZRECORDS_MAX 2560 /* Max records allowed in the log */ +#else +#define ZRECORDS_MAX 1536 /* Max records allowed in the log */ +#endif +#define ZRECORDS_DEFAULT 1024 /* default records in log if zrecs is not specificed in boot-args */ + +static TUNABLE(uint32_t, log_records, "zrecs", ZRECORDS_DEFAULT); + +static void +zone_enable_logging(zone_t z) +{ + z->zlog_btlog = btlog_create(log_records, MAX_ZTRACE_DEPTH, + (corruption_debug_flag == FALSE) /* caller_will_remove_entries_for_element? */); + + if (z->zlog_btlog) { + printf("zone: logging started for zone %s%s\n", + zone_heap_name(z), z->z_name); + } else { + printf("zone: couldn't allocate memory for zrecords, turning off zleak logging\n"); + z->zone_logging = false; + } +} + +/** + * @function zone_setup_logging + * + * @abstract + * Optionally sets up a zone for logging. + * + * @discussion + * We recognized two boot-args: + * + * zlog= + * zrecs= + * + * The zlog arg is used to specify the zone name that should be logged, + * and zrecs is used to control the size of the log. + * + * If zrecs is not specified, a default value is used. + */ +static void +zone_setup_logging(zone_t z) +{ + char zone_name[MAX_ZONE_NAME]; /* Temp. buffer for the zone name */ + char zlog_name[MAX_ZONE_NAME]; /* Temp. buffer to create the strings zlog1, zlog2 etc... */ + char zlog_val[MAX_ZONE_NAME]; /* the zone name we're logging, if any */ + + /* + * Don't allow more than ZRECORDS_MAX records even if the user asked for more. + * + * This prevents accidentally hogging too much kernel memory + * and making the system unusable. + */ + if (log_records > ZRECORDS_MAX) { + log_records = ZRECORDS_MAX; + } + + /* + * Append kalloc heap name to zone name (if zone is used by kalloc) + */ + snprintf(zone_name, MAX_ZONE_NAME, "%s%s", zone_heap_name(z), z->z_name); + + /* zlog0 isn't allowed. */ + for (int i = 1; i <= max_num_zones_to_log; i++) { + snprintf(zlog_name, MAX_ZONE_NAME, "zlog%d", i); + + if (PE_parse_boot_argn(zlog_name, zlog_val, sizeof(zlog_val)) && + track_this_zone(zone_name, zlog_val)) { + z->zone_logging = true; + num_zones_logged++; + break; + } + } + + /* + * Backwards compat. with the old boot-arg used to specify single zone + * logging i.e. zlog Needs to happen after the newer zlogn checks + * because the prefix will match all the zlogn + * boot-args. + */ + if (!z->zone_logging && + PE_parse_boot_argn("zlog", zlog_val, sizeof(zlog_val)) && + track_this_zone(zone_name, zlog_val)) { + z->zone_logging = true; + num_zones_logged++; + } + + + /* + * If we want to log a zone, see if we need to allocate buffer space for + * the log. + * + * Some vm related zones are zinit'ed before we can do a kmem_alloc, so + * we have to defer allocation in that case. + * + * zone_init() will finish the job. + * + * If we want to log one of the VM related zones that's set up early on, + * we will skip allocation of the log until zinit is called again later + * on some other zone. + */ + if (z->zone_logging && startup_phase >= STARTUP_SUB_KMEM_ALLOC) { + zone_enable_logging(z); + } +} + +/* + * Each record in the log contains a pointer to the zone element it refers to, + * and a small array to hold the pc's from the stack trace. A + * record is added to the log each time a zalloc() is done in the zone_of_interest. For leak debugging, + * the record is cleared when a zfree() is done. For corruption debugging, the log tracks both allocs and frees. + * If the log fills, old records are replaced as if it were a circular buffer. + */ + + +/* + * Decide if we want to log this zone by doing a string compare between a zone name and the name + * of the zone to log. Return true if the strings are equal, false otherwise. Because it's not + * possible to include spaces in strings passed in via the boot-args, a period in the logname will + * match a space in the zone name. + */ + +/* + * Test if we want to log this zalloc/zfree event. We log if this is the zone we're interested in and + * the buffer for the records has been allocated. + */ + +#define DO_LOGGING(z) (z->zlog_btlog != NULL) +#else /* !ZONE_ENABLE_LOGGING */ +#define DO_LOGGING(z) 0 +#endif /* !ZONE_ENABLE_LOGGING */ +#if CONFIG_ZLEAKS + +/* + * The zone leak detector, abbreviated 'zleak', keeps track of a subset of the currently outstanding + * allocations made by the zone allocator. Every zleak_sample_factor allocations in each zone, we capture a + * backtrace. Every free, we examine the table and determine if the allocation was being tracked, + * and stop tracking it if it was being tracked. + * + * We track the allocations in the zallocations hash table, which stores the address that was returned from + * the zone allocator. Each stored entry in the zallocations table points to an entry in the ztraces table, which + * stores the backtrace associated with that allocation. This provides uniquing for the relatively large + * backtraces - we don't store them more than once. + * + * Data collection begins when the zone map is 50% full, and only occurs for zones that are taking up + * a large amount of virtual space. + */ +#define ZLEAK_STATE_ENABLED 0x01 /* Zone leak monitoring should be turned on if zone_map fills up. */ +#define ZLEAK_STATE_ACTIVE 0x02 /* We are actively collecting traces. */ +#define ZLEAK_STATE_ACTIVATING 0x04 /* Some thread is doing setup; others should move along. */ +#define ZLEAK_STATE_FAILED 0x08 /* Attempt to allocate tables failed. We will not try again. */ +static uint32_t zleak_state = 0; /* State of collection, as above */ +static unsigned int zleak_sample_factor = 1000; /* Allocations per sample attempt */ + +bool panic_include_ztrace = FALSE; /* Enable zleak logging on panic */ +vm_size_t zleak_global_tracking_threshold; /* Size of zone map at which to start collecting data */ +vm_size_t zleak_per_zone_tracking_threshold; /* Size a zone will have before we will collect data on it */ + +/* + * Counters for allocation statistics. + */ + +/* Times two active records want to occupy the same spot */ +static unsigned int z_alloc_collisions = 0; +static unsigned int z_trace_collisions = 0; + +/* Times a new record lands on a spot previously occupied by a freed allocation */ +static unsigned int z_alloc_overwrites = 0; +static unsigned int z_trace_overwrites = 0; + +/* Times a new alloc or trace is put into the hash table */ +static unsigned int z_alloc_recorded = 0; +static unsigned int z_trace_recorded = 0; + +/* Times zleak_log returned false due to not being able to acquire the lock */ +static unsigned int z_total_conflicts = 0; + +/* + * Structure for keeping track of an allocation + * An allocation bucket is in use if its element is not NULL + */ +struct zallocation { + uintptr_t za_element; /* the element that was zalloc'ed or zfree'ed, NULL if bucket unused */ + vm_size_t za_size; /* how much memory did this allocation take up? */ + uint32_t za_trace_index; /* index into ztraces for backtrace associated with allocation */ + /* TODO: #if this out */ + uint32_t za_hit_count; /* for determining effectiveness of hash function */ +}; + +/* Size must be a power of two for the zhash to be able to just mask off bits instead of mod */ +static uint32_t zleak_alloc_buckets = CONFIG_ZLEAK_ALLOCATION_MAP_NUM; +static uint32_t zleak_trace_buckets = CONFIG_ZLEAK_TRACE_MAP_NUM; + +vm_size_t zleak_max_zonemap_size; + +/* Hashmaps of allocations and their corresponding traces */ +static struct zallocation* zallocations; +static struct ztrace* ztraces; + +/* not static so that panic can see this, see kern/debug.c */ +struct ztrace* top_ztrace; + +/* Lock to protect zallocations, ztraces, and top_ztrace from concurrent modification. */ +static LCK_GRP_DECLARE(zleak_lock_grp, "zleak_lock"); +static LCK_SPIN_DECLARE(zleak_lock, &zleak_lock_grp); + +/* + * Initializes the zone leak monitor. Called from zone_init() + */ +__startup_func +static void +zleak_init(vm_size_t max_zonemap_size) +{ + char scratch_buf[16]; + boolean_t zleak_enable_flag = FALSE; + + zleak_max_zonemap_size = max_zonemap_size; + zleak_global_tracking_threshold = max_zonemap_size / 2; + zleak_per_zone_tracking_threshold = zleak_global_tracking_threshold / 8; + +#if CONFIG_EMBEDDED + if (PE_parse_boot_argn("-zleakon", scratch_buf, sizeof(scratch_buf))) { + zleak_enable_flag = TRUE; + printf("zone leak detection enabled\n"); + } else { + zleak_enable_flag = FALSE; + printf("zone leak detection disabled\n"); + } +#else /* CONFIG_EMBEDDED */ + /* -zleakoff (flag to disable zone leak monitor) */ + if (PE_parse_boot_argn("-zleakoff", scratch_buf, sizeof(scratch_buf))) { + zleak_enable_flag = FALSE; + printf("zone leak detection disabled\n"); + } else { + zleak_enable_flag = TRUE; + printf("zone leak detection enabled\n"); + } +#endif /* CONFIG_EMBEDDED */ + + /* zfactor=XXXX (override how often to sample the zone allocator) */ + if (PE_parse_boot_argn("zfactor", &zleak_sample_factor, sizeof(zleak_sample_factor))) { + printf("Zone leak factor override: %u\n", zleak_sample_factor); + } + + /* zleak-allocs=XXXX (override number of buckets in zallocations) */ + if (PE_parse_boot_argn("zleak-allocs", &zleak_alloc_buckets, sizeof(zleak_alloc_buckets))) { + printf("Zone leak alloc buckets override: %u\n", zleak_alloc_buckets); + /* uses 'is power of 2' trick: (0x01000 & 0x00FFF == 0) */ + if (zleak_alloc_buckets == 0 || (zleak_alloc_buckets & (zleak_alloc_buckets - 1))) { + printf("Override isn't a power of two, bad things might happen!\n"); + } + } + + /* zleak-traces=XXXX (override number of buckets in ztraces) */ + if (PE_parse_boot_argn("zleak-traces", &zleak_trace_buckets, sizeof(zleak_trace_buckets))) { + printf("Zone leak trace buckets override: %u\n", zleak_trace_buckets); + /* uses 'is power of 2' trick: (0x01000 & 0x00FFF == 0) */ + if (zleak_trace_buckets == 0 || (zleak_trace_buckets & (zleak_trace_buckets - 1))) { + printf("Override isn't a power of two, bad things might happen!\n"); + } + } + + if (zleak_enable_flag) { + zleak_state = ZLEAK_STATE_ENABLED; + } +} + +/* + * Support for kern.zleak.active sysctl - a simplified + * version of the zleak_state variable. + */ +int +get_zleak_state(void) +{ + if (zleak_state & ZLEAK_STATE_FAILED) { + return -1; + } + if (zleak_state & ZLEAK_STATE_ACTIVE) { + return 1; + } + return 0; +} + +kern_return_t +zleak_activate(void) +{ + kern_return_t retval; + vm_size_t z_alloc_size = zleak_alloc_buckets * sizeof(struct zallocation); + vm_size_t z_trace_size = zleak_trace_buckets * sizeof(struct ztrace); + void *allocations_ptr = NULL; + void *traces_ptr = NULL; + + /* Only one thread attempts to activate at a time */ + if (zleak_state & (ZLEAK_STATE_ACTIVE | ZLEAK_STATE_ACTIVATING | ZLEAK_STATE_FAILED)) { + return KERN_SUCCESS; + } + + /* Indicate that we're doing the setup */ + lck_spin_lock(&zleak_lock); + if (zleak_state & (ZLEAK_STATE_ACTIVE | ZLEAK_STATE_ACTIVATING | ZLEAK_STATE_FAILED)) { + lck_spin_unlock(&zleak_lock); + return KERN_SUCCESS; + } + + zleak_state |= ZLEAK_STATE_ACTIVATING; + lck_spin_unlock(&zleak_lock); + + /* Allocate and zero tables */ + retval = kmem_alloc_kobject(kernel_map, (vm_offset_t*)&allocations_ptr, z_alloc_size, VM_KERN_MEMORY_DIAG); + if (retval != KERN_SUCCESS) { + goto fail; + } + + retval = kmem_alloc_kobject(kernel_map, (vm_offset_t*)&traces_ptr, z_trace_size, VM_KERN_MEMORY_DIAG); + if (retval != KERN_SUCCESS) { + goto fail; + } + + bzero(allocations_ptr, z_alloc_size); + bzero(traces_ptr, z_trace_size); + + /* Everything's set. Install tables, mark active. */ + zallocations = allocations_ptr; + ztraces = traces_ptr; + + /* + * Initialize the top_ztrace to the first entry in ztraces, + * so we don't have to check for null in zleak_log + */ + top_ztrace = &ztraces[0]; + + /* + * Note that we do need a barrier between installing + * the tables and setting the active flag, because the zfree() + * path accesses the table without a lock if we're active. + */ + lck_spin_lock(&zleak_lock); + zleak_state |= ZLEAK_STATE_ACTIVE; + zleak_state &= ~ZLEAK_STATE_ACTIVATING; + lck_spin_unlock(&zleak_lock); + + return 0; + +fail: + /* + * If we fail to allocate memory, don't further tax + * the system by trying again. + */ + lck_spin_lock(&zleak_lock); + zleak_state |= ZLEAK_STATE_FAILED; + zleak_state &= ~ZLEAK_STATE_ACTIVATING; + lck_spin_unlock(&zleak_lock); + + if (allocations_ptr != NULL) { + kmem_free(kernel_map, (vm_offset_t)allocations_ptr, z_alloc_size); + } + + if (traces_ptr != NULL) { + kmem_free(kernel_map, (vm_offset_t)traces_ptr, z_trace_size); + } + + return retval; +} + +static inline void +zleak_activate_if_needed(void) +{ + if (__probable((zleak_state & ZLEAK_STATE_ENABLED) == 0)) { + return; + } + if (zleak_state & ZLEAK_STATE_ACTIVE) { + return; + } + if (zone_submaps_approx_size() < zleak_global_tracking_threshold) { + return; + } + + kern_return_t kr = zleak_activate(); + if (kr != KERN_SUCCESS) { + printf("Failed to activate live zone leak debugging (%d).\n", kr); + } +} + +static inline void +zleak_track_if_needed(zone_t z) +{ + if (__improbable(zleak_state & ZLEAK_STATE_ACTIVE)) { + if (!z->zleak_on && + zone_size_wired(z) >= zleak_per_zone_tracking_threshold) { + z->zleak_on = true; + } + } +} + +/* + * TODO: What about allocations that never get deallocated, + * especially ones with unique backtraces? Should we wait to record + * until after boot has completed? + * (How many persistent zallocs are there?) + */ + +/* + * This function records the allocation in the allocations table, + * and stores the associated backtrace in the traces table + * (or just increments the refcount if the trace is already recorded) + * If the allocation slot is in use, the old allocation is replaced with the new allocation, and + * the associated trace's refcount is decremented. + * If the trace slot is in use, it returns. + * The refcount is incremented by the amount of memory the allocation consumes. + * The return value indicates whether to try again next time. + */ +static boolean_t +zleak_log(uintptr_t* bt, + uintptr_t addr, + uint32_t depth, + vm_size_t allocation_size) +{ + /* Quit if there's someone else modifying the hash tables */ + if (!lck_spin_try_lock(&zleak_lock)) { + z_total_conflicts++; + return FALSE; + } + + struct zallocation* allocation = &zallocations[hashaddr(addr, zleak_alloc_buckets)]; + + uint32_t trace_index = hashbacktrace(bt, depth, zleak_trace_buckets); + struct ztrace* trace = &ztraces[trace_index]; + + allocation->za_hit_count++; + trace->zt_hit_count++; + + /* + * If the allocation bucket we want to be in is occupied, and if the occupier + * has the same trace as us, just bail. + */ + if (allocation->za_element != (uintptr_t) 0 && trace_index == allocation->za_trace_index) { + z_alloc_collisions++; + + lck_spin_unlock(&zleak_lock); + return TRUE; + } + + /* STEP 1: Store the backtrace in the traces array. */ + /* A size of zero indicates that the trace bucket is free. */ + + if (trace->zt_size > 0 && bcmp(trace->zt_stack, bt, (depth * sizeof(uintptr_t))) != 0) { + /* + * Different unique trace with same hash! + * Just bail - if we're trying to record the leaker, hopefully the other trace will be deallocated + * and get out of the way for later chances + */ + trace->zt_collisions++; + z_trace_collisions++; + + lck_spin_unlock(&zleak_lock); + return TRUE; + } else if (trace->zt_size > 0) { + /* Same trace, already added, so increment refcount */ + trace->zt_size += allocation_size; + } else { + /* Found an unused trace bucket, record the trace here! */ + if (trace->zt_depth != 0) { /* if this slot was previously used but not currently in use */ + z_trace_overwrites++; + } + + z_trace_recorded++; + trace->zt_size = allocation_size; + memcpy(trace->zt_stack, bt, (depth * sizeof(uintptr_t))); + + trace->zt_depth = depth; + trace->zt_collisions = 0; + } + + /* STEP 2: Store the allocation record in the allocations array. */ + + if (allocation->za_element != (uintptr_t) 0) { + /* + * Straight up replace any allocation record that was there. We don't want to do the work + * to preserve the allocation entries that were there, because we only record a subset of the + * allocations anyways. + */ + + z_alloc_collisions++; + + struct ztrace* associated_trace = &ztraces[allocation->za_trace_index]; + /* Knock off old allocation's size, not the new allocation */ + associated_trace->zt_size -= allocation->za_size; + } else if (allocation->za_trace_index != 0) { + /* Slot previously used but not currently in use */ + z_alloc_overwrites++; + } + + allocation->za_element = addr; + allocation->za_trace_index = trace_index; + allocation->za_size = allocation_size; + + z_alloc_recorded++; + + if (top_ztrace->zt_size < trace->zt_size) { + top_ztrace = trace; + } + + lck_spin_unlock(&zleak_lock); + return TRUE; +} + +/* + * Free the allocation record and release the stacktrace. + * This should be as fast as possible because it will be called for every free. + */ +__attribute__((noinline)) +static void +zleak_free(uintptr_t addr, + vm_size_t allocation_size) +{ + if (addr == (uintptr_t) 0) { + return; + } + + struct zallocation* allocation = &zallocations[hashaddr(addr, zleak_alloc_buckets)]; + + /* Double-checked locking: check to find out if we're interested, lock, check to make + * sure it hasn't changed, then modify it, and release the lock. + */ + + if (allocation->za_element == addr && allocation->za_trace_index < zleak_trace_buckets) { + /* if the allocation was the one, grab the lock, check again, then delete it */ + lck_spin_lock(&zleak_lock); + + if (allocation->za_element == addr && allocation->za_trace_index < zleak_trace_buckets) { + struct ztrace *trace; + + /* allocation_size had better match what was passed into zleak_log - otherwise someone is freeing into the wrong zone! */ + if (allocation->za_size != allocation_size) { + panic("Freeing as size %lu memory that was allocated with size %lu\n", + (uintptr_t)allocation_size, (uintptr_t)allocation->za_size); + } + + trace = &ztraces[allocation->za_trace_index]; + + /* size of 0 indicates trace bucket is unused */ + if (trace->zt_size > 0) { + trace->zt_size -= allocation_size; + } + + /* A NULL element means the allocation bucket is unused */ + allocation->za_element = 0; + } + lck_spin_unlock(&zleak_lock); + } +} + +#else +static inline void +zleak_activate_if_needed(void) +{ +} + +static inline void +zleak_track_if_needed(__unused zone_t z) +{ +} +#endif /* CONFIG_ZLEAKS */ +#if ZONE_ENABLE_LOGGING || CONFIG_ZLEAKS + +__attribute__((noinline)) +static void +zalloc_log_or_trace_leaks(zone_t zone, vm_offset_t addr, void *fp) +{ + uintptr_t zbt[MAX_ZTRACE_DEPTH]; /* used in zone leak logging and zone leak detection */ + unsigned int numsaved = 0; + +#if ZONE_ENABLE_LOGGING + if (DO_LOGGING(zone)) { + numsaved = backtrace(zbt, MAX_ZTRACE_DEPTH, NULL); + btlog_add_entry(zone->zlog_btlog, (void *)addr, + ZOP_ALLOC, (void **)zbt, numsaved); + } +#endif /* ZONE_ENABLE_LOGGING */ + +#if CONFIG_ZLEAKS + /* + * Zone leak detection: capture a backtrace every zleak_sample_factor + * allocations in this zone. + */ + if (__improbable(zone->zleak_on)) { + if (sample_counter(&zone->zleak_capture, zleak_sample_factor)) { + /* Avoid backtracing twice if zone logging is on */ + if (numsaved == 0) { + numsaved = backtrace_frame(zbt, MAX_ZTRACE_DEPTH, fp, NULL); + } + /* Sampling can fail if another sample is happening at the same time in a different zone. */ + if (!zleak_log(zbt, addr, numsaved, zone_elem_size(zone))) { + /* If it failed, roll back the counter so we sample the next allocation instead. */ + zone->zleak_capture = zleak_sample_factor; + } + } + } + + if (__improbable(zone_leaks_scan_enable && + !(zone_elem_size(zone) & (sizeof(uintptr_t) - 1)))) { + unsigned int count, idx; + /* Fill element, from tail, with backtrace in reverse order */ + if (numsaved == 0) { + numsaved = backtrace_frame(zbt, MAX_ZTRACE_DEPTH, fp, NULL); + } + count = (unsigned int)(zone_elem_size(zone) / sizeof(uintptr_t)); + if (count >= numsaved) { + count = numsaved - 1; + } + for (idx = 0; idx < count; idx++) { + ((uintptr_t *)addr)[count - 1 - idx] = zbt[idx + 1]; + } + } +#endif /* CONFIG_ZLEAKS */ +} + +static inline bool +zalloc_should_log_or_trace_leaks(zone_t zone, vm_size_t elem_size) +{ +#if ZONE_ENABLE_LOGGING + if (DO_LOGGING(zone)) { + return true; + } +#endif /* ZONE_ENABLE_LOGGING */ +#if CONFIG_ZLEAKS + /* + * Zone leak detection: capture a backtrace every zleak_sample_factor + * allocations in this zone. + */ + if (zone->zleak_on) { + return true; + } + if (zone_leaks_scan_enable && !(elem_size & (sizeof(uintptr_t) - 1))) { + return true; + } +#endif /* CONFIG_ZLEAKS */ + return false; +} + +#endif /* ZONE_ENABLE_LOGGING || CONFIG_ZLEAKS */ +#if ZONE_ENABLE_LOGGING + +__attribute__((noinline)) +static void +zfree_log_trace(zone_t zone, vm_offset_t addr, void *fp) +{ + /* + * See if we're doing logging on this zone. + * + * There are two styles of logging used depending on + * whether we're trying to catch a leak or corruption. + */ + if (__improbable(DO_LOGGING(zone))) { + if (corruption_debug_flag) { + uintptr_t zbt[MAX_ZTRACE_DEPTH]; + unsigned int numsaved; + /* + * We're logging to catch a corruption. + * + * Add a record of this zfree operation to log. + */ + numsaved = backtrace_frame(zbt, MAX_ZTRACE_DEPTH, fp, NULL); + btlog_add_entry(zone->zlog_btlog, (void *)addr, ZOP_FREE, + (void **)zbt, numsaved); + } else { + /* + * We're logging to catch a leak. + * + * Remove any record we might have for this element + * since it's being freed. Note that we may not find it + * if the buffer overflowed and that's OK. + * + * Since the log is of a limited size, old records get + * overwritten if there are more zallocs than zfrees. + */ + btlog_remove_entries_for_element(zone->zlog_btlog, (void *)addr); + } + } +} + +#endif /* ZONE_ENABLE_LOGGING */ + +/* These functions outside of CONFIG_ZLEAKS because they are also used in + * mbuf.c for mbuf leak-detection. This is why they lack the z_ prefix. + */ + +/* "Thomas Wang's 32/64 bit mix functions." http://www.concentric.net/~Ttwang/tech/inthash.htm */ +uintptr_t +hash_mix(uintptr_t x) +{ +#ifndef __LP64__ + x += ~(x << 15); + x ^= (x >> 10); + x += (x << 3); + x ^= (x >> 6); + x += ~(x << 11); + x ^= (x >> 16); +#else + x += ~(x << 32); + x ^= (x >> 22); + x += ~(x << 13); + x ^= (x >> 8); + x += (x << 3); + x ^= (x >> 15); + x += ~(x << 27); + x ^= (x >> 31); +#endif + return x; +} + +uint32_t +hashbacktrace(uintptr_t* bt, uint32_t depth, uint32_t max_size) +{ + uintptr_t hash = 0; + uintptr_t mask = max_size - 1; + + while (depth) { + hash += bt[--depth]; + } + + hash = hash_mix(hash) & mask; + + assert(hash < max_size); + + return (uint32_t) hash; +} + +/* + * TODO: Determine how well distributed this is + * max_size must be a power of 2. i.e 0x10000 because 0x10000-1 is 0x0FFFF which is a great bitmask + */ +uint32_t +hashaddr(uintptr_t pt, uint32_t max_size) +{ + uintptr_t hash = 0; + uintptr_t mask = max_size - 1; + + hash = hash_mix(pt) & mask; + + assert(hash < max_size); + + return (uint32_t) hash; +} + +#endif /* !ZALLOC_TEST */ +#pragma mark zone (re)fill +#if !ZALLOC_TEST + +/*! + * @defgroup Zone Refill + * @{ + * + * @brief + * Functions handling The zone refill machinery. + * + * @discussion + * Zones are refilled based on 3 mechanisms: direct expansion, async expansion, + * VM-specific replenishment. Zones using VM-specific replenishment are marked + * with the @c z_replenishes property set. + * + * @c zalloc_ext() is the codepath that kicks the zone refill when the zone is + * dropping below half of its @c z_elems_rsv (0 for most zones) and will: + * + * - call @c zone_expand_locked() directly if the caller is allowed to block, + * + * - wakeup the asynchroous expansion thread call if the caller is not allowed + * to block. + * + * - call @c zone_replenish_locked() to kick the replenish state machine. + * + * + *

Synchronous expansion

+ * + * This mechanism is actually the only one that may refill a zone, and all the + * other ones funnel through this one eventually. + * + * @c zone_expand_locked() implements the core of the expansion mechanism, + * and will do so while a caller specified predicate is true. + * + * Zone expansion allows for up to 2 threads to concurrently refill the zone: + * - one VM privileged thread, + * - one regular thread. + * + * Regular threads that refill will put down their identity in @c z_expander, + * so that priority inversion avoidance can be implemented. + * + * However, VM privileged threads are allowed to use VM page reserves, + * which allows for the system to recover from extreme memory pressure + * situations, allowing for the few allocations that @c zone_gc() or + * killing processes require. + * + * When a VM privileged thread is also expanding, the @c z_expander_vm_priv bit + * is set. @c z_expander is not necessarily the identity of this VM privileged + * thread (it is if the VM privileged thread came in first, but wouldn't be, and + * could even be @c THREAD_NULL otherwise). + * + * Note that the pageout-scan daemon might be BG and is VM privileged. To avoid + * spending a whole pointer on priority inheritance for VM privileged threads + * (and other issues related to having two owners), we use the rwlock boost as + * a stop gap to avoid priority inversions. + * + * + *

Chunk wiring policies

+ * + * Zones allocate memory in chunks of @c zone_t::z_chunk_pages pages at a time + * to try to minimize fragmentation relative to element sizes not aligning with + * a chunk size well. However, this can grow large and be hard to fulfill on + * a system under a lot of memory pressure (chunks can be as long as 8 pages on + * 4k page systems). + * + * This is why, when under memory pressure the system allows chunks to be + * partially populated. The metadata of the first page in the chunk maintains + * the count of actually populated pages. + * + * The metadata for addresses assigned to a zone are found of 4 queues: + * - @c z_pageq_empty has chunk heads with populated pages and no allocated + * elements (those can be targeted by @c zone_gc()), + * - @c z_pageq_partial has chunk heads with populated pages that are partially + * used, + * - @c z_pageq_full has chunk heads with populated pages with no free elements + * left, + * - @c z_pageq_va has either chunk heads for sequestered VA space assigned to + * the zone forever (if @c z_va_sequester is enabled), or the first secondary + * metadata for a chunk whose corresponding page is not populated in the + * chunk. + * + * When new pages need to be wired/populated, chunks from the @c z_pageq_va + * queues are preferred. + * + * + *

Asynchronous expansion

+ * + * This mechanism allows for refilling zones used mostly with non blocking + * callers. It relies on a thread call (@c zone_expand_callout) which will + * iterate all zones and refill the ones marked with @c z_async_refilling. + * + * NOTE: If the calling thread for zalloc_noblock is lower priority than + * the thread_call, then zalloc_noblock to an empty zone may succeed. + * + * + *

Dealing with zone allocations from the mach VM code

+ * + * The implementation of the mach VM itself uses the zone allocator + * for things like the vm_map_entry data structure. In order to prevent + * an infinite recursion problem when adding more pages to a zone, @c zalloc + * uses a replenish thread to refill the VM layer's zones before they have + * too few remaining free entries. The reserved remaining free entries + * guarantee that the VM routines can get entries from already mapped pages. + * + * In order for that to work, the amount of allocations in the nested + * case have to be bounded. There are currently 2 replenish zones, and + * if each needs 1 element of each zone to add a new page to itself, that + * gives us a minumum reserve of 2 elements. + * + * There is also a deadlock issue with the zone garbage collection thread, + * or any thread that is trying to free zone pages. While holding + * the kernel's map lock they may need to allocate new VM map entries, hence + * we need enough reserve to allow them to get past the point of holding the + * map lock. After freeing that page, the GC thread will wait in + * @c zone_reclaim() until the replenish threads can finish. + * Since there's only 1 GC thread at a time, that adds a minimum of 1 to the + * reserve size. + * + * Since the minumum amount you can add to a zone is 1 page, + * we'll use 16K (from ARM) as the refill size on all platforms. + * + * When a refill zone drops to half that available, i.e. REFILL_SIZE / 2, + * @c zalloc_ext() will wake the replenish thread. The replenish thread runs + * until at least REFILL_SIZE worth of free elements exist, before sleeping again. + * In the meantime threads may continue to use the reserve until there are only + * REFILL_SIZE / 4 elements left. Below that point only the replenish threads + * themselves and the GC thread may continue to use from the reserve. + */ + +static thread_call_data_t zone_expand_callout; + +static inline kma_flags_t +zone_kma_flags(zone_t z, zalloc_flags_t flags) +{ + kma_flags_t kmaflags = KMA_KOBJECT | KMA_ZERO; + + if (z->z_noencrypt) { + kmaflags |= KMA_NOENCRYPT; + } + if (flags & Z_NOPAGEWAIT) { + kmaflags |= KMA_NOPAGEWAIT; + } + if (z->z_permanent || (!z->z_destructible && z->z_va_sequester)) { + kmaflags |= KMA_PERMANENT; + } + if (z->z_submap_idx == Z_SUBMAP_IDX_GENERAL && + z->kalloc_heap != KHEAP_ID_NONE) { + kmaflags |= KMA_KHEAP; + } + + return kmaflags; +} + +/*! + * @function zcram_and_lock() + * + * @brief + * Prepare some memory for being usable for allocation purposes. + * + * @discussion + * Prepare memory in [addr + ptoa(pg_start), addr + ptoa(pg_end)) + * to be usable in the zone. + * + * This function assumes the metadata is already populated for the range. + * + * Calling this function with @c pg_start being 0 means that the memory + * is either a partial chunk, or a full chunk, that isn't published anywhere + * and the initialization can happen without locks held. + * + * Calling this function with a non zero @c pg_start means that we are extending + * an existing chunk: the memory in [addr, addr + ptoa(pg_start)), + * is already usable and published in the zone, so extending it requires holding + * the zone lock. + * + * @param zone The zone to cram new populated pages into + * @param addr The base address for the chunk(s) + * @param pg_va_new The number of virtual pages newly assigned to the zone + * @param pg_start The first newly populated page relative to @a addr. + * @param pg_end The after-last newly populated page relative to @a addr. + * @param kind The kind of memory assigned to the zone. + */ +static void +zcram_and_lock(zone_t zone, vm_offset_t addr, uint32_t pg_va_new, + uint32_t pg_start, uint32_t pg_end, zone_addr_kind_t kind) +{ + zone_id_t zindex = zone_index(zone); + vm_offset_t elem_size = zone_elem_size(zone); + uint32_t free_start = 0, free_end = 0; + + struct zone_page_metadata *meta = zone_meta_from_addr(addr); + uint32_t chunk_pages = zone->z_chunk_pages; + + assert(pg_start < pg_end && pg_end <= chunk_pages); + + if (pg_start == 0) { + uint16_t chunk_len = (uint16_t)pg_end; + uint16_t secondary_len = ZM_SECONDARY_PAGE; + bool inline_bitmap = false; + + if (zone->z_percpu) { + chunk_len = 1; + secondary_len = ZM_SECONDARY_PCPU_PAGE; + assert(pg_end == zpercpu_count()); + } + if (!zone->z_permanent) { + inline_bitmap = zone->z_chunk_elems <= 32 * chunk_pages; + } + + meta[0] = (struct zone_page_metadata){ + .zm_index = zindex, + .zm_inline_bitmap = inline_bitmap, + .zm_chunk_len = chunk_len, + }; + if (kind == ZONE_ADDR_FOREIGN) { + /* Never hit z_pageq_empty */ + meta[0].zm_alloc_size = ZM_ALLOC_SIZE_LOCK; + } + + for (uint16_t i = 1; i < chunk_pages; i++) { + meta[i] = (struct zone_page_metadata){ + .zm_index = zindex, + .zm_inline_bitmap = inline_bitmap, + .zm_chunk_len = secondary_len, + .zm_page_index = i, + }; + } + + free_end = (uint32_t)ptoa(chunk_len) / elem_size; + if (!zone->z_permanent) { + zone_meta_bits_init(meta, free_end, zone->z_chunk_elems); + } + } else { + assert(!zone->z_percpu && !zone->z_permanent); + + free_end = (uint32_t)ptoa(pg_end) / elem_size; + free_start = (uint32_t)ptoa(pg_start) / elem_size; + } + +#if VM_MAX_TAG_ZONES + if (__improbable(zone->tags)) { + assert(kind == ZONE_ADDR_NATIVE && !zone->z_percpu); + ztMemoryAdd(zone, addr + ptoa(pg_start), + ptoa(pg_end - pg_start)); + } +#endif /* VM_MAX_TAG_ZONES */ + + /* + * Insert the initialized pages / metadatas into the right lists. + */ + + zone_lock(zone); + assert(zone->z_self == zone); + + if (pg_start != 0) { + assert(meta->zm_chunk_len == pg_start); + + zone_meta_bits_merge(meta, free_start, free_end); + meta->zm_chunk_len = (uint16_t)pg_end; + + /* + * consume the zone_meta_lock_in_partial() + * done in zone_expand_locked() + */ + zone_meta_alloc_size_sub(zone, meta, ZM_ALLOC_SIZE_LOCK); + zone_meta_remqueue(zone, meta); + } + + if (zone->z_permanent || meta->zm_alloc_size) { + zone_meta_queue_push(zone, &zone->z_pageq_partial, meta); + } else { + zone_meta_queue_push(zone, &zone->z_pageq_empty, meta); + zone->z_wired_empty += zone->z_percpu ? 1 : pg_end; + } + if (pg_end < chunk_pages) { + /* push any non populated residual VA on z_pageq_va */ + zone_meta_queue_push(zone, &zone->z_pageq_va, meta + pg_end); + } + + zone_elems_free_add(zone, free_end - free_start); + zone->z_elems_avail += free_end - free_start; + zone->z_wired_cur += zone->z_percpu ? 1 : pg_end - pg_start; + if (pg_va_new) { + zone->z_va_cur += zone->z_percpu ? 1 : pg_va_new; + } + if (zone->z_wired_hwm < zone->z_wired_cur) { + zone->z_wired_hwm = zone->z_wired_cur; + } + + os_atomic_add(&zones_phys_page_mapped_count, pg_end - pg_start, relaxed); +} + +static void +zcram(zone_t zone, vm_offset_t addr, uint32_t pages, zone_addr_kind_t kind) +{ + uint32_t chunk_pages = zone->z_chunk_pages; + + assert(pages % chunk_pages == 0); + for (; pages > 0; pages -= chunk_pages, addr += ptoa(chunk_pages)) { + zcram_and_lock(zone, addr, chunk_pages, 0, chunk_pages, kind); + zone_unlock(zone); + } +} + +void +zone_cram_foreign(zone_t zone, vm_offset_t newmem, vm_size_t size) +{ + uint32_t pages = (uint32_t)atop(size); + + if (!from_zone_map(newmem, size, ZONE_ADDR_FOREIGN)) { + panic("zone_cram_foreign: foreign memory [%p] being crammed is " + "outside of expected range", (void *)newmem); + } + if (!zone->z_allows_foreign) { + panic("zone_cram_foreign: foreign memory [%p] being crammed in " + "zone '%s%s' not expecting it", (void *)newmem, + zone_heap_name(zone), zone_name(zone)); + } + if (size % ptoa(zone->z_chunk_pages)) { + panic("zone_cram_foreign: foreign memory [%p] being crammed has " + "invalid size %zx", (void *)newmem, (size_t)size); + } + if (startup_phase >= STARTUP_SUB_ZALLOC) { + panic("zone_cram_foreign: foreign memory [%p] being crammed " + "after zalloc is initialized", (void *)newmem); + } + + bzero((void *)newmem, size); + zcram(zone, newmem, pages, ZONE_ADDR_FOREIGN); +} + +void +zone_fill_initially(zone_t zone, vm_size_t nelems) +{ + kma_flags_t kmaflags; + kern_return_t kr; + vm_offset_t addr; + uint32_t pages; + + assert(!zone->z_permanent && !zone->collectable && !zone->z_destructible); + assert(zone->z_elems_avail == 0); + + kmaflags = zone_kma_flags(zone, Z_WAITOK) | KMA_PERMANENT; + pages = zone_alloc_pages_for_nelems(zone, nelems); + kr = kernel_memory_allocate(zone_submap(zone), &addr, ptoa(pages), + 0, kmaflags, VM_KERN_MEMORY_ZONE); + if (kr != KERN_SUCCESS) { + panic("kernel_memory_allocate() of %u pages failed", pages); + } + + zone_meta_populate(addr, ptoa(pages)); + zcram(zone, addr, pages, ZONE_ADDR_NATIVE); +} + +static vm_offset_t +zone_allocate_va(zone_t z, zalloc_flags_t flags) +{ + kma_flags_t kmaflags = zone_kma_flags(z, flags) | KMA_VAONLY; + vm_size_t size = ptoa(z->z_chunk_pages); + kern_return_t kr; + vm_offset_t addr; + + kr = kernel_memory_allocate(zone_submap(z), &addr, size, 0, + kmaflags, VM_KERN_MEMORY_ZONE); + +#if !__LP64__ + if (kr == KERN_NO_SPACE && z->z_replenishes) { + /* + * On 32bit the zone submaps do not have as much VA + * available, so use the VA reserved map for this + * purpose. + */ + vm_map_t map = zone_submaps[Z_SUBMAP_IDX_VA_RESERVE]; + kr = kernel_memory_allocate(map, &addr, size, 0, + kmaflags, VM_KERN_MEMORY_ZONE); + } +#endif + + if (kr == KERN_SUCCESS) { +#if ZALLOC_EARLY_GAPS + if (__improbable(zone_caching_disabled < 0)) { + zone_allocate_random_early_gap(z); + } +#endif /* ZALLOC_EARLY_GAPS */ + zone_meta_populate(addr, size); + return addr; + } + + panic_include_zprint = TRUE; +#if CONFIG_ZLEAKS + if ((zleak_state & ZLEAK_STATE_ACTIVE)) { + panic_include_ztrace = TRUE; + } +#endif /* CONFIG_ZLEAKS */ + zone_t zone_largest = zone_find_largest(); + panic("zalloc: zone map exhausted while allocating from zone [%s%s], " + "likely due to memory leak in zone [%s%s] " + "(%luM, %d elements allocated)", + zone_heap_name(z), zone_name(z), + zone_heap_name(zone_largest), zone_name(zone_largest), + (unsigned long)zone_size_wired(zone_largest) >> 20, + zone_count_allocated(zone_largest)); +} + +static bool +zone_expand_pred_nope(__unused zone_t z) +{ + return false; +} + +static inline void +ZONE_TRACE_VM_KERN_REQUEST_START(vm_size_t size) +{ +#if DEBUG || DEVELOPMENT + VM_DEBUG_CONSTANT_EVENT(vm_kern_request, VM_KERN_REQUEST, DBG_FUNC_START, + size, 0, 0, 0); +#else + (void)size; +#endif +} + +static inline void +ZONE_TRACE_VM_KERN_REQUEST_END(uint32_t pages) +{ +#if DEBUG || DEVELOPMENT + task_t task = current_task(); + if (pages && task) { + ledger_credit(task->ledger, task_ledgers.pages_grabbed_kern, pages); + } + VM_DEBUG_CONSTANT_EVENT(vm_kern_request, VM_KERN_REQUEST, DBG_FUNC_END, + pages, 0, 0, 0); +#else + (void)pages; +#endif +} + +static void +zone_expand_locked(zone_t z, zalloc_flags_t flags, bool (*pred)(zone_t)) +{ + thread_t self = current_thread(); + bool vm_priv = (self->options & TH_OPT_VMPRIV); + bool clear_vm_priv; + + for (;;) { + if (!pred) { + /* NULL pred means "try just once" */ + pred = zone_expand_pred_nope; + } else if (!pred(z)) { + return; + } + + if (vm_priv && !z->z_expander_vm_priv) { + /* + * Claim the vm priv overcommit slot + * + * We do not track exact ownership for VM privileged + * threads, so use the rwlock boost as a stop-gap + * just in case. + */ + set_thread_rwlock_boost(); + z->z_expander_vm_priv = true; + clear_vm_priv = true; + } else { + clear_vm_priv = false; + } + + if (z->z_expander == NULL) { + z->z_expander = self; + break; + } + if (clear_vm_priv) { + break; + } + + if (flags & Z_NOPAGEWAIT) { + return; + } + + z->z_expanding_wait = true; + lck_spin_sleep_with_inheritor(&z->z_lock, LCK_SLEEP_DEFAULT, + &z->z_expander, z->z_expander, + TH_UNINT, TIMEOUT_WAIT_FOREVER); + } + + do { + struct zone_page_metadata *meta = NULL; + uint32_t new_va = 0, cur_pages = 0, min_pages = 0, pages = 0; + vm_page_t page_list = NULL; + vm_offset_t addr = 0; + int waited = 0; + + /* + * While we hold the zone lock, look if there's VA we can: + * - complete from partial pages, + * - reuse from the sequester list. + * + * When the page is being populated we pretend we allocated + * an extra element so that zone_gc() can't attempt to free + * the chunk (as it could become empty while we wait for pages). + */ + if (!zone_pva_is_null(z->z_pageq_va)) { + meta = zone_meta_queue_pop_native(z, + &z->z_pageq_va, &addr); + if (meta->zm_chunk_len == ZM_SECONDARY_PAGE) { + cur_pages = meta->zm_page_index; + meta -= cur_pages; + addr -= ptoa(cur_pages); + zone_meta_lock_in_partial(z, meta, cur_pages); + } + } + zone_unlock(z); + + /* + * Do the zone leak activation here because zleak_activate() + * may block, and can't be done on the way out. + * + * Trigger jetsams via the vm_pageout_garbage_collect thread if + * we're running out of zone memory + */ + zleak_activate_if_needed(); + if (zone_map_nearing_exhaustion()) { + thread_wakeup((event_t)&vm_pageout_garbage_collect); + } + + /* + * And now allocate pages to populate our VA. + */ + if (z->z_percpu) { + min_pages = z->z_chunk_pages; + } else { + min_pages = (uint32_t)atop(round_page(zone_elem_size(z))); + } + + ZONE_TRACE_VM_KERN_REQUEST_START(ptoa(z->z_chunk_pages - cur_pages)); + + while (pages < z->z_chunk_pages - cur_pages) { + vm_page_t m = vm_page_grab(); + + if (m) { + pages++; + m->vmp_snext = page_list; + page_list = m; + vm_page_zero_fill(m); + continue; + } + + if (pages >= min_pages && (vm_pool_low() || waited)) { + break; + } + + if ((flags & Z_NOPAGEWAIT) == 0) { + waited++; + VM_PAGE_WAIT(); + continue; + } + + /* + * Undo everything and bail out: + * + * - free pages + * - undo the fake allocation if any + * - put the VA back on the VA page queue. + */ + vm_page_free_list(page_list, FALSE); + ZONE_TRACE_VM_KERN_REQUEST_END(pages); + + zone_lock(z); + + if (cur_pages) { + zone_meta_unlock_from_partial(z, meta, cur_pages); + } + if (meta) { + zone_meta_queue_push(z, &z->z_pageq_va, + meta + cur_pages); + } + goto page_shortage; + } + + /* + * If we didn't find pre-allocated VA, then allocate a chunk + * of VA here. + */ + if (addr == 0) { + addr = zone_allocate_va(z, flags); + meta = zone_meta_from_addr(addr); + new_va = z->z_chunk_pages; + } + + kernel_memory_populate_with_pages(zone_submap(z), + addr + ptoa(cur_pages), ptoa(pages), page_list, + zone_kma_flags(z, flags), VM_KERN_MEMORY_ZONE); + + ZONE_TRACE_VM_KERN_REQUEST_END(pages); + + zcram_and_lock(z, addr, new_va, cur_pages, cur_pages + pages, + ZONE_ADDR_NATIVE); + } while (pred(z)); + +page_shortage: + zleak_track_if_needed(z); + + if (clear_vm_priv) { + z->z_expander_vm_priv = false; + clear_thread_rwlock_boost(); + } + if (z->z_expander == self) { + z->z_expander = THREAD_NULL; + } + if (z->z_expanding_wait) { + z->z_expanding_wait = false; + wakeup_all_with_inheritor(&z->z_expander, THREAD_AWAKENED); + } +} + +static bool +zalloc_needs_refill(zone_t zone) +{ + if (zone->z_elems_free > zone->z_elems_rsv) { + return false; + } + if (zone->z_wired_cur < zone->z_wired_max) { + return true; + } + if (zone->exhaustible) { + return false; + } + if (zone->expandable) { + /* + * If we're expandable, just don't go through this again. + */ + zone->z_wired_max = ~0u; + return true; + } + zone_unlock(zone); + + panic_include_zprint = true; +#if CONFIG_ZLEAKS + if (zleak_state & ZLEAK_STATE_ACTIVE) { + panic_include_ztrace = true; + } +#endif /* CONFIG_ZLEAKS */ + panic("zone '%s%s' exhausted", zone_heap_name(zone), zone_name(zone)); +} + +static void +zone_expand_async(__unused thread_call_param_t p0, __unused thread_call_param_t p1) +{ + zone_foreach(z) { + if (z->no_callout) { + /* z_async_refilling will never be set */ + continue; + } + + if (z->z_replenishes) { + /* those use the zone_replenish_thread */ + continue; + } + + zone_lock(z); + if (z->z_self && z->z_async_refilling) { + z->z_async_refilling = false; + zone_expand_locked(z, Z_WAITOK, zalloc_needs_refill); + } + zone_unlock(z); + } +} + +static inline void +zone_expand_async_schedule_if_needed(zone_t zone) +{ + if (zone->z_elems_free > zone->z_elems_rsv || zone->z_async_refilling || + zone->no_callout) { + return; + } + + if (!zone->expandable && zone->z_wired_cur >= zone->z_wired_max) { + return; + } + + if (zone->z_elems_free == 0 || !vm_pool_low()) { + zone->z_async_refilling = true; + thread_call_enter(&zone_expand_callout); + } +} + +#endif /* !ZALLOC_TEST */ +#pragma mark zone replenishing (VM allocations) +#if !ZALLOC_TEST + +/* + * Tracks how many zone_replenish threads are active, because zone_gc() wants + * for those to be finished before it proceeds. + * + * This counts how many replenish threads are active in + * ZONE_REPLENISH_ACTIVE_INC increments, + * and uses the low bit to track if there are any waiters. + */ +#define ZONE_REPLENISH_ACTIVE_NONE 0u +#define ZONE_REPLENISH_ACTIVE_WAITER_BIT 1u +#define ZONE_REPLENISH_ACTIVE_INC 2u +#define ZONE_REPLENISH_ACTIVE_MASK (~ZONE_REPLENISH_ACTIVE_WAITER_BIT) +static unsigned _Atomic zone_replenish_active; +static unsigned zone_replenish_wakeups; +static unsigned zone_replenish_wakeups_initiated; +static unsigned zone_replenish_throttle_count; + +#define ZONE_REPLENISH_TARGET (16 * 1024) + +static void +zone_replenish_wait_if_needed(void) +{ + /* + * This check can be racy, the reserves ought to be enough + * to compensate for a little race + */ + while (os_atomic_load(&zone_replenish_active, relaxed) != + ZONE_REPLENISH_ACTIVE_NONE) { + unsigned o_active, n_active; + + assert_wait(&zone_replenish_active, THREAD_UNINT); + + os_atomic_rmw_loop(&zone_replenish_active, o_active, n_active, relaxed, { + if (o_active == ZONE_REPLENISH_ACTIVE_NONE) { + os_atomic_rmw_loop_give_up({ + clear_wait(current_thread(), THREAD_AWAKENED); + return; + }); + } + if (o_active & ZONE_REPLENISH_ACTIVE_WAITER_BIT) { + os_atomic_rmw_loop_give_up(break); + } + n_active = o_active | ZONE_REPLENISH_ACTIVE_WAITER_BIT; + }); + thread_block(THREAD_CONTINUE_NULL); + } +} + +__attribute__((noinline)) +static void +zone_replenish_locked(zone_t zone) +{ + thread_t thr = current_thread(); + uint32_t min_free; + + zone_replenish_wakeups++; + + /* + * We'll let threads continue to allocate under the reserve: + * - until it depleted to 50% for regular threads, + * - until it depleted to 25% for VM_PRIV threads. + * + * After that only TH_OPT_ZONE_PRIV threads may continue. + */ + if (thr->options & TH_OPT_VMPRIV) { + min_free = zone->z_elems_rsv / 4; + } else { + min_free = zone->z_elems_rsv / 2; + } + + while (zone->z_elems_free <= zone->z_elems_rsv) { + /* + * Wakeup the replenish thread if not running. + */ + if (!zone->z_async_refilling) { + os_atomic_add(&zone_replenish_active, + ZONE_REPLENISH_ACTIVE_INC, relaxed); + zone->z_async_refilling = true; + zone_replenish_wakeups_initiated++; + thread_wakeup(&zone->z_elems_rsv); + } + + if (zone->z_elems_free > min_free) { + break; + } + + /* + * TH_OPT_ZONE_PRIV threads are the GC thread and a replenish + * thread itself. + * + * Replenish threads *need* to use the reserve. GC threads need + * to get through the current allocation, but then will wait at + * a higher level after they've dropped any locks which would + * deadlock the replenish thread. + * + * The value of (refill_level / 2) in the previous bit of code + * should have given us headroom even though this thread didn't + * wait. + */ + if (thr->options & TH_OPT_ZONE_PRIV) { + assert(zone->z_elems_free != 0); + break; + } + + if (startup_phase < STARTUP_SUB_MACH_IPC) { + panic("vm_map_steal_memory didn't steal enough memory: " + "trying to grow [%s%s] before the scheduler has started", + zone_heap_name(zone), zone_name(zone)); + } + + /* + * Wait for the replenish threads to add more elements + * for us to allocate from. + */ + zone_replenish_throttle_count++; + zone->z_replenish_wait = true; + assert_wait_timeout(zone, THREAD_UNINT, 1, NSEC_PER_MSEC); + zone_unlock(zone); + thread_block(THREAD_CONTINUE_NULL); + zone_lock(zone); + zone->z_replenish_wait = false; + + assert(zone->z_self == zone); + } +} + +static bool +zone_replenish_needed(zone_t z) +{ + return z->z_elems_free <= z->z_elems_rsv; +} + +/* + * High priority VM privileged thread used to asynchronously refill a given zone. + * These are needed for data structures used by the lower level VM itself. The + * replenish thread maintains a reserve of elements, so that the VM will never + * block in the zone allocator. + */ +__dead2 +static void +zone_replenish_thread(void *_z, wait_result_t __unused wr) +{ + unsigned o_active, n_active; + zone_t z = _z; + + zone_lock(z); + assert(z->z_self == z); + assert(z->z_async_refilling && z->z_replenishes); + + zone_expand_locked(z, Z_WAITOK, zone_replenish_needed); + + if (z->z_replenish_wait) { + /* Wakeup any potentially throttled allocations */ + z->z_replenish_wait = false; + thread_wakeup(z); + } + + /* wakeup zone_reclaim() callers that were possibly waiting */ + os_atomic_rmw_loop(&zone_replenish_active, o_active, n_active, relaxed, { + if (os_sub_overflow(o_active, ZONE_REPLENISH_ACTIVE_INC, &n_active)) { + panic("zone_replenish_active corrupt: %d", o_active); + } + if ((n_active & ZONE_REPLENISH_ACTIVE_MASK) == 0) { + n_active = ZONE_REPLENISH_ACTIVE_NONE; + } + }); + + if (n_active == ZONE_REPLENISH_ACTIVE_NONE && + (o_active & ZONE_REPLENISH_ACTIVE_WAITER_BIT)) { + thread_wakeup(&zone_replenish_active); + } + + z->z_async_refilling = false; + assert_wait(&z->z_elems_rsv, THREAD_UNINT); + + zone_unlock(z); + + thread_block_parameter(zone_replenish_thread, z); + __builtin_unreachable(); +} + +void +zone_replenish_configure(zone_t z) +{ + thread_t th; + kern_return_t kr; + char name[MAXTHREADNAMESIZE]; + + zone_lock(z); + assert(!z->z_replenishes && !z->z_destructible); + z->z_elems_rsv = (uint16_t)(ZONE_REPLENISH_TARGET / zone_elem_size(z)); + z->z_replenishes = true; + os_atomic_add(&zone_replenish_active, ZONE_REPLENISH_ACTIVE_INC, relaxed); + z->z_async_refilling = true; + zone_unlock(z); + + kr = kernel_thread_create(zone_replenish_thread, z, MAXPRI_KERNEL, &th); + if (kr != KERN_SUCCESS) { + panic("zone_replenish_configure, thread create: 0x%x", kr); + } + /* make sure this thread can't lose its stack */ + assert(th->reserved_stack == th->kernel_stack); + + snprintf(name, sizeof(name), "z_replenish(%s)", zone_name(z)); + thread_set_thread_name(th, name); + + thread_mtx_lock(th); + th->options |= TH_OPT_VMPRIV | TH_OPT_ZONE_PRIV; + thread_start(th); + thread_mtx_unlock(th); + + thread_deallocate(th); +} + +/*! @} */ +#endif /* !ZALLOC_TEST */ +#pragma mark zone jetsam integration +#if !ZALLOC_TEST + +/* + * We're being very conservative here and picking a value of 95%. We might need to lower this if + * we find that we're not catching the problem and are still hitting zone map exhaustion panics. + */ +#define ZONE_MAP_JETSAM_LIMIT_DEFAULT 95 + +/* + * Trigger zone-map-exhaustion jetsams if the zone map is X% full, where X=zone_map_jetsam_limit. + * Can be set via boot-arg "zone_map_jetsam_limit". Set to 95% by default. + */ +TUNABLE_WRITEABLE(unsigned int, zone_map_jetsam_limit, "zone_map_jetsam_limit", + ZONE_MAP_JETSAM_LIMIT_DEFAULT); + +void +get_zone_map_size(uint64_t *current_size, uint64_t *capacity) +{ + vm_offset_t phys_pages = os_atomic_load(&zones_phys_page_mapped_count, relaxed); + *current_size = ptoa_64(phys_pages); + *capacity = ptoa_64(zone_phys_mapped_max_pages); +} + +void +get_largest_zone_info(char *zone_name, size_t zone_name_len, uint64_t *zone_size) +{ + zone_t largest_zone = zone_find_largest(); + + /* + * Append kalloc heap name to zone name (if zone is used by kalloc) + */ + snprintf(zone_name, zone_name_len, "%s%s", + zone_heap_name(largest_zone), largest_zone->z_name); + + *zone_size = zone_size_wired(largest_zone); +} + +bool +zone_map_nearing_exhaustion(void) +{ + uint64_t phys_pages = os_atomic_load(&zones_phys_page_mapped_count, relaxed); + return phys_pages * 100 > zone_phys_mapped_max_pages * zone_map_jetsam_limit; +} + + +#define VMENTRY_TO_VMOBJECT_COMPARISON_RATIO 98 + +/* + * Tries to kill a single process if it can attribute one to the largest zone. If not, wakes up the memorystatus thread + * to walk through the jetsam priority bands and kill processes. + */ +static void +kill_process_in_largest_zone(void) +{ + pid_t pid = -1; + zone_t largest_zone = zone_find_largest(); + + printf("zone_map_exhaustion: Zone mapped %lld of %lld, used %lld, capacity %lld [jetsam limit %d%%]\n", + ptoa_64(os_atomic_load(&zones_phys_page_mapped_count, relaxed)), + ptoa_64(zone_phys_mapped_max_pages), + (uint64_t)zone_submaps_approx_size(), + (uint64_t)(zone_foreign_size() + zone_native_size()), + zone_map_jetsam_limit); + printf("zone_map_exhaustion: Largest zone %s%s, size %lu\n", zone_heap_name(largest_zone), + largest_zone->z_name, (uintptr_t)zone_size_wired(largest_zone)); + + /* + * We want to make sure we don't call this function from userspace. + * Or we could end up trying to synchronously kill the process + * whose context we're in, causing the system to hang. + */ + assert(current_task() == kernel_task); + + /* + * If vm_object_zone is the largest, check to see if the number of + * elements in vm_map_entry_zone is comparable. + * + * If so, consider vm_map_entry_zone as the largest. This lets us target + * a specific process to jetsam to quickly recover from the zone map + * bloat. + */ + if (largest_zone == vm_object_zone) { + unsigned int vm_object_zone_count = zone_count_allocated(vm_object_zone); + unsigned int vm_map_entry_zone_count = zone_count_allocated(vm_map_entry_zone); + /* Is the VM map entries zone count >= 98% of the VM objects zone count? */ + if (vm_map_entry_zone_count >= ((vm_object_zone_count * VMENTRY_TO_VMOBJECT_COMPARISON_RATIO) / 100)) { + largest_zone = vm_map_entry_zone; + printf("zone_map_exhaustion: Picking VM map entries as the zone to target, size %lu\n", + (uintptr_t)zone_size_wired(largest_zone)); + } + } + + /* TODO: Extend this to check for the largest process in other zones as well. */ + if (largest_zone == vm_map_entry_zone) { + pid = find_largest_process_vm_map_entries(); + } else { + printf("zone_map_exhaustion: Nothing to do for the largest zone [%s%s]. " + "Waking up memorystatus thread.\n", zone_heap_name(largest_zone), + largest_zone->z_name); + } + if (!memorystatus_kill_on_zone_map_exhaustion(pid)) { + printf("zone_map_exhaustion: Call to memorystatus failed, victim pid: %d\n", pid); + } +} + +#endif /* !ZALLOC_TEST */ +#pragma mark zfree +#if !ZALLOC_TEST +#if KASAN_ZALLOC + +/*! + * @defgroup zfree + * @{ + * + * @brief + * The codepath for zone frees. + * + * @discussion + * There are 4 major ways to allocate memory that end up in the zone allocator: + * - @c zfree() + * - @c zfree_percpu() + * - @c kfree*() + * - @c zfree_permanent() + * + * While permanent zones have their own allocation scheme, all other codepaths + * will eventually go through the @c zfree_ext() choking point. + * + * Ignoring the @c gzalloc_free() codepath, the decision tree looks like this: + * + * zfree_ext() + * ├───> zfree_cached() ────────────────╮ + * │ │ │ + * │ │ │ + * │ ├───> zfree_cached_slow() ───┤ + * │ │ │ │ + * │ │ v │ + * ╰───────┴───> zfree_item() ──────────┴───> + * + * + * @c zfree_ext() takes care of all the generic work to perform on an element + * before it is freed (zeroing, logging, tagging, ...) then will hand it off to: + * - @c zfree_item() if zone caching is off + * - @c zfree_cached() if zone caching is on. + * + * @c zfree_cached can take a number of decisions: + * - a fast path if the (f) or (a) magazines have space (preemption disabled), + * - using the cpu local or recirculation depot calling @c zfree_cached_slow(), + * - falling back to @c zfree_item() when CPU caching has been disabled. + */ + +/* + * Called from zfree() to add the element being freed to the KASan quarantine. + * + * Returns true if the newly-freed element made it into the quarantine without + * displacing another, false otherwise. In the latter case, addrp points to the + * address of the displaced element, which will be freed by the zone. + */ +static bool +kasan_quarantine_freed_element( + zone_t *zonep, /* the zone the element is being freed to */ + void **addrp) /* address of the element being freed */ +{ + zone_t zone = *zonep; + void *addr = *addrp; + + /* + * Resize back to the real allocation size and hand off to the KASan + * quarantine. `addr` may then point to a different allocation, if the + * current element replaced another in the quarantine. The zone then + * takes ownership of the swapped out free element. + */ + vm_size_t usersz = zone_elem_size(zone) - 2 * zone->z_kasan_redzone; + vm_size_t sz = usersz; + + if (addr && zone->z_kasan_redzone) { + kasan_check_free((vm_address_t)addr, usersz, KASAN_HEAP_ZALLOC); + addr = (void *)kasan_dealloc((vm_address_t)addr, &sz); + assert(sz == zone_elem_size(zone)); + } + if (addr && !zone->kasan_noquarantine) { + kasan_free(&addr, &sz, KASAN_HEAP_ZALLOC, zonep, usersz, true); + if (!addr) { + return TRUE; + } + } + if (addr && zone->kasan_noquarantine) { + kasan_unpoison(addr, zone_elem_size(zone)); + } + *addrp = addr; + return FALSE; +} + +#endif /* KASAN_ZALLOC */ + +__header_always_inline void +zfree_drop(zone_t zone, struct zone_page_metadata *meta, zone_element_t ze, + bool recirc) +{ + vm_offset_t esize = zone_elem_size(zone); + + if (zone_meta_mark_free(meta, ze) == recirc) { + zone_meta_double_free_panic(zone, ze, __func__); + } + + vm_offset_t old_size = meta->zm_alloc_size; + vm_offset_t max_size = ptoa(meta->zm_chunk_len) + ZM_ALLOC_SIZE_LOCK; + vm_offset_t new_size = zone_meta_alloc_size_sub(zone, meta, esize); + + if (new_size == 0) { + /* whether the page was on the intermediate or all_used, queue, move it to free */ + zone_meta_requeue(zone, &zone->z_pageq_empty, meta); + zone->z_wired_empty += meta->zm_chunk_len; + } else if (old_size + esize > max_size) { + /* first free element on page, move from all_used */ + zone_meta_requeue(zone, &zone->z_pageq_partial, meta); + } +} + +static void +zfree_item(zone_t zone, struct zone_page_metadata *meta, zone_element_t ze) +{ + /* transfer preemption count to lock */ + zone_lock_nopreempt_check_contention(zone, NULL); + + zfree_drop(zone, meta, ze, false); + zone_elems_free_add(zone, 1); + + zone_unlock(zone); +} + +__attribute__((noinline)) +static void +zfree_cached_slow(zone_t zone, struct zone_page_metadata *meta, + zone_element_t ze, zone_cache_t cache) +{ + struct zone_depot mags = STAILQ_HEAD_INITIALIZER(mags); + zone_magazine_t mag = NULL; + uint16_t n = 0; + + if (zone_meta_is_free(meta, ze)) { + zone_meta_double_free_panic(zone, ze, __func__); + } + + if (zone == zc_magazine_zone) { + mag = (zone_magazine_t)zone_element_addr(ze, + zone_elem_size(zone)); +#if KASAN_ZALLOC + kasan_poison_range((vm_offset_t)mag, zone_elem_size(zone), + ASAN_VALID); +#endif + } else { + mag = zone_magazine_alloc(Z_NOWAIT); + if (__improbable(mag == NULL)) { + return zfree_item(zone, meta, ze); + } + mag->zm_cur = 1; + mag->zm_elems[0] = ze; + } + + mag = zone_magazine_replace(&cache->zc_free_cur, + &cache->zc_free_elems, mag); + + z_debug_assert(cache->zc_free_cur <= 1); + z_debug_assert(mag->zm_cur == zc_mag_size()); + + STAILQ_INSERT_HEAD(&mags, mag, zm_link); + n = 1; + + if (cache->zc_depot_max >= 2 * zc_mag_size()) { + /* + * If we can use the local depot (zc_depot_max allows for + * 2 magazines worth of elements) then: + * + * 1. if we have space for an extra depot locally, + * push it, and leave. + * + * 2. if we overflow, then take (1 / zc_recirc_denom) + * of the depot out, in order to migrate it to the + * recirculation depot. + */ + zone_depot_lock_nopreempt(cache); + + if ((cache->zc_depot_cur + 2) * zc_mag_size() <= + cache->zc_depot_max) { + cache->zc_depot_cur++; + STAILQ_INSERT_TAIL(&cache->zc_depot, mag, zm_link); + return zone_depot_unlock(cache); + } + + while (zc_recirc_denom * cache->zc_depot_cur * zc_mag_size() >= + (zc_recirc_denom - 1) * cache->zc_depot_max) { + mag = STAILQ_FIRST(&cache->zc_depot); + STAILQ_REMOVE_HEAD(&cache->zc_depot, zm_link); + STAILQ_INSERT_TAIL(&mags, mag, zm_link); + cache->zc_depot_cur--; + n++; + } + + zone_depot_unlock(cache); + } else { + enable_preemption(); + } + + /* + * Preflight validity of all the elements before we touch the zone + * metadata, and then insert them into the recirculation depot. + */ + STAILQ_FOREACH(mag, &mags, zm_link) { + for (uint16_t i = 0; i < zc_mag_size(); i++) { + zone_element_validate(zone, mag->zm_elems[i]); + } + } + + zone_lock_check_contention(zone, cache); + + STAILQ_FOREACH(mag, &mags, zm_link) { + for (uint16_t i = 0; i < zc_mag_size(); i++) { + zone_element_t e = mag->zm_elems[i]; + + if (!zone_meta_mark_free(zone_meta_from_element(e), e)) { + zone_meta_double_free_panic(zone, e, __func__); + } + } + } + STAILQ_CONCAT(&zone->z_recirc, &mags); + zone->z_recirc_cur += n; + + zone_elems_free_add(zone, n * zc_mag_size()); + + zone_unlock(zone); +} + +static void +zfree_cached(zone_t zone, struct zone_page_metadata *meta, zone_element_t ze) +{ + zone_cache_t cache = zpercpu_get(zone->z_pcpu_cache); + + if (cache->zc_free_cur >= zc_mag_size()) { + if (cache->zc_alloc_cur >= zc_mag_size()) { + return zfree_cached_slow(zone, meta, ze, cache); + } + zone_cache_swap_magazines(cache); + } + + if (__improbable(cache->zc_alloc_elems == NULL)) { + return zfree_item(zone, meta, ze); + } + + if (zone_meta_is_free(meta, ze)) { + zone_meta_double_free_panic(zone, ze, __func__); + } + + uint16_t idx = cache->zc_free_cur++; + if (idx >= zc_mag_size()) { + zone_accounting_panic(zone, "zc_free_cur overflow"); + } + cache->zc_free_elems[idx] = ze; + + enable_preemption(); +} + +/* + * The function is noinline when zlog can be used so that the backtracing can + * reliably skip the zfree_ext() and zfree_log_trace() + * boring frames. + */ +#if ZONE_ENABLE_LOGGING +__attribute__((noinline)) +#endif /* ZONE_ENABLE_LOGGING */ +void +zfree_ext(zone_t zone, zone_stats_t zstats, void *addr) +{ + struct zone_page_metadata *page_meta; + vm_offset_t elem = (vm_offset_t)addr; + vm_size_t elem_size = zone_elem_size(zone); + zone_element_t ze; + + DTRACE_VM2(zfree, zone_t, zone, void*, addr); + TRACE_MACHLEAKS(ZFREE_CODE, ZFREE_CODE_2, elem_size, elem); +#if VM_MAX_TAG_ZONES + if (__improbable(zone->tags)) { + vm_tag_t tag = *ztSlot(zone, elem) >> 1; + // set the tag with b0 clear so the block remains inuse + *ztSlot(zone, elem) = 0xFFFE; + vm_tag_update_zone_size(tag, zone->tag_zone_index, + -(long)elem_size); + } +#endif /* VM_MAX_TAG_ZONES */ + +#if KASAN_ZALLOC + if (kasan_quarantine_freed_element(&zone, &addr)) { + return; + } + /* + * kasan_quarantine_freed_element() might return a different + * {zone, addr} than the one being freed for kalloc heaps. + * + * Make sure we reload everything. + */ + elem = (vm_offset_t)addr; + elem_size = zone_elem_size(zone); +#endif +#if CONFIG_ZLEAKS + /* + * Zone leak detection: un-track the allocation + */ + if (__improbable(zone->zleak_on)) { + zleak_free(elem, elem_size); + } +#endif /* CONFIG_ZLEAKS */ +#if ZONE_ENABLE_LOGGING + if (__improbable(DO_LOGGING(zone))) { + zfree_log_trace(zone, elem, __builtin_frame_address(0)); + } +#endif /* ZONE_ENABLE_LOGGING */ +#if CONFIG_GZALLOC + if (__improbable(zone->gzalloc_tracked)) { + return gzalloc_free(zone, zstats, addr); + } +#endif /* CONFIG_GZALLOC */ + + page_meta = zone_element_resolve(zone, elem, elem_size, &ze); + ze.ze_value |= zfree_clear_or_poison(zone, elem, elem_size); +#if KASAN_ZALLOC + if (zone->z_percpu) { + zpercpu_foreach_cpu(i) { + kasan_poison_range(elem + ptoa(i), elem_size, + ASAN_HEAP_FREED); + } + } else { + kasan_poison_range(elem, elem_size, ASAN_HEAP_FREED); + } +#endif + + disable_preemption(); + zpercpu_get(zstats)->zs_mem_freed += elem_size; + + if (zone->z_pcpu_cache) { + return zfree_cached(zone, page_meta, ze); + } + + return zfree_item(zone, page_meta, ze); +} + +void +(zfree)(union zone_or_view zov, void *addr) +{ + zone_t zone = zov.zov_view->zv_zone; + zone_stats_t zstats = zov.zov_view->zv_stats; + assert(!zone->z_percpu); + zfree_ext(zone, zstats, addr); +} + +void +zfree_percpu(union zone_or_view zov, void *addr) +{ + zone_t zone = zov.zov_view->zv_zone; + zone_stats_t zstats = zov.zov_view->zv_stats; + assert(zone->z_percpu); + zfree_ext(zone, zstats, (void *)__zpcpu_demangle(addr)); +} + +/*! @} */ +#endif /* !ZALLOC_TEST */ +#pragma mark zalloc +#if !ZALLOC_TEST + +/*! + * @defgroup zalloc + * @{ + * + * @brief + * The codepath for zone allocations. + * + * @discussion + * There are 4 major ways to allocate memory that end up in the zone allocator: + * - @c zalloc(), @c zalloc_flags(), ... + * - @c zalloc_percpu() + * - @c kalloc*() + * - @c zalloc_permanent() + * + * While permanent zones have their own allocation scheme, all other codepaths + * will eventually go through the @c zalloc_ext() choking point. + * + * Ignoring the @c zalloc_gz() codepath, the decision tree looks like this: + * + * zalloc_ext() + * │ + * ├───> zalloc_cached() ──────> zalloc_cached_fast() ───╮ + * │ │ ^ │ + * │ │ │ │ + * │ ╰───> zalloc_cached_slow() ───╯ │ + * │ │ │ + * │<─────────────────╮ ├─────────────╮ │ + * │ │ │ │ │ + * │ │ v │ │ + * │<───────╮ ╭──> zalloc_item_slow() ────┤ │ + * │ │ │ │ │ + * │ │ │ v │ + * ╰───> zalloc_item() ──────────> zalloc_item_fast() ───┤ + * │ + * v + * zalloc_return() + * + * + * + * The @c zalloc_item() track is used when zone caching is off: + * - @c zalloc_item_fast() is used when there are enough elements available, + * - @c zalloc_item_slow() is used when a refill is needed, which can cause + * the zone to grow. This is the only codepath that refills. + * + * This track uses the zone lock for serialization: + * - taken in @c zalloc_item(), + * - maintained during @c zalloc_item_slow() (possibly dropped and re-taken), + * - dropped in @c zalloc_item_fast(). + * + * + * The @c zalloc_cached() track is used when zone caching is on: + * - @c zalloc_cached_fast() is taken when the cache has elements, + * - @c zalloc_cached_slow() is taken if a cache refill is needed. + * It can chose many strategies: + * ~ @c zalloc_cached_from_depot() to try to reuse cpu stashed magazines, + * ~ using the global recirculation depot @c z_recirc, + * ~ using zalloc_import() if the zone has enough elements, + * ~ falling back to the @c zalloc_item() track if zone caching is disabled + * due to VM pressure or the zone has no available elements. + * + * This track disables preemption for serialization: + * - preemption is disabled in @c zalloc_cached(), + * - kept disabled during @c zalloc_cached_slow(), converted into a zone lock + * if switching to @c zalloc_item_slow(), + * - preemption is reenabled in @c zalloc_cached_fast(). + * + * @c zalloc_cached_from_depot() also takes depot locks (taken by the caller, + * released by @c zalloc_cached_from_depot(). + * + * In general the @c zalloc_*_slow() codepaths deal with refilling and will + * tail call into the @c zalloc_*_fast() code to perform the actual allocation. + * + * @c zalloc_return() is the final function everyone tail calls into, + * which prepares the element for consumption by the caller and deals with + * common treatment (zone logging, tags, kasan, validation, ...). + */ + +/*! + * @function zalloc_import + * + * @brief + * Import @c n elements in the specified array, opposite of @c zfree_drop(). + * + * @param zone The zone to import elements from + * @param elems The array to import into + * @param n The number of elements to import. Must be non zero, + * and smaller than @c zone->z_elems_free. + */ +__header_always_inline void +zalloc_import(zone_t zone, zone_element_t *elems, uint32_t n) +{ + vm_size_t esize = zone_elem_size(zone); + uint32_t i = 0; + + assertf(STAILQ_EMPTY(&zone->z_recirc), + "Trying to import from zone %p [%s%s] with non empty recirc", + zone, zone_heap_name(zone), zone_name(zone)); + + do { + vm_offset_t page, eidx, size = 0; + struct zone_page_metadata *meta; + + if (!zone_pva_is_null(zone->z_pageq_partial)) { + meta = zone_pva_to_meta(zone->z_pageq_partial); + page = zone_pva_to_addr(zone->z_pageq_partial); + } else if (!zone_pva_is_null(zone->z_pageq_empty)) { + meta = zone_pva_to_meta(zone->z_pageq_empty); + page = zone_pva_to_addr(zone->z_pageq_empty); + zone_counter_sub(zone, z_wired_empty, meta->zm_chunk_len); + } else { + zone_accounting_panic(zone, "z_elems_free corruption"); + } + + if (!zone_has_index(zone, meta->zm_index)) { + zone_page_metadata_index_confusion_panic(zone, page, meta); + } + + vm_offset_t old_size = meta->zm_alloc_size; + vm_offset_t max_size = ptoa(meta->zm_chunk_len) + ZM_ALLOC_SIZE_LOCK; + + do { + eidx = zone_meta_find_and_clear_bit(zone, meta); + elems[i++] = zone_element_encode(page, eidx, ZPM_AUTO); + size += esize; + } while (i < n && old_size + size + esize <= max_size); + + vm_offset_t new_size = zone_meta_alloc_size_add(zone, meta, size); + + if (new_size + esize > max_size) { + zone_meta_requeue(zone, &zone->z_pageq_full, meta); + } else if (old_size == 0) { + /* remove from free, move to intermediate */ + zone_meta_requeue(zone, &zone->z_pageq_partial, meta); + } + } while (i < n); +} + +/*! + * @function zalloc_return + * + * @brief + * Performs the tail-end of the work required on allocations before the caller + * uses them. + * + * @discussion + * This function is called without any zone lock held, + * and preemption back to the state it had when @c zalloc_ext() was called. + * + * @param zone The zone we're allocating from. + * @param ze The encoded element we just allocated. + * @param flags The flags passed to @c zalloc_ext() (for Z_ZERO). + * @param elem_size The element size for this zone. + * @param freemag An optional magazine that needs to be freed. + */ +__attribute__((noinline)) +static void * +zalloc_return(zone_t zone, zone_element_t ze, zalloc_flags_t flags, + vm_offset_t elem_size, zone_magazine_t freemag) +{ + vm_offset_t addr = zone_element_addr(ze, elem_size); + +#if KASAN_ZALLOC + if (zone->z_percpu) { + zpercpu_foreach_cpu(i) { + kasan_poison_range(addr + ptoa(i), elem_size, + ASAN_VALID); + } + } else { + kasan_poison_range(addr, elem_size, ASAN_VALID); + } +#endif +#if ZALLOC_ENABLE_POISONING + zalloc_validate_element(zone, addr, elem_size, zone_element_prot(ze)); +#endif /* ZALLOC_ENABLE_POISONING */ +#if ZONE_ENABLE_LOGGING || CONFIG_ZLEAKS + if (__improbable(zalloc_should_log_or_trace_leaks(zone, elem_size))) { + zalloc_log_or_trace_leaks(zone, addr, __builtin_frame_address(0)); + } +#endif /* ZONE_ENABLE_LOGGING || CONFIG_ZLEAKS */ +#if KASAN_ZALLOC + if (zone->z_kasan_redzone) { + addr = kasan_alloc(addr, elem_size, + elem_size - 2 * zone->z_kasan_redzone, + zone->z_kasan_redzone); + elem_size -= 2 * zone->z_kasan_redzone; + } + /* + * Initialize buffer with unique pattern only if memory + * wasn't expected to be zeroed. + */ + if (!zone->z_free_zeroes && !(flags & Z_ZERO)) { + kasan_leak_init(addr, elem_size); + } +#endif /* KASAN_ZALLOC */ + if ((flags & Z_ZERO) && !zone->z_free_zeroes) { + bzero((void *)addr, elem_size); + } + +#if VM_MAX_TAG_ZONES + if (__improbable(zone->tags)) { + vm_tag_t tag = zalloc_flags_get_tag(flags); + if (tag == VM_KERN_MEMORY_NONE) { + tag = VM_KERN_MEMORY_KALLOC; + } + // set the tag with b0 clear so the block remains inuse + *ztSlot(zone, addr) = (vm_tag_t)(tag << 1); + vm_tag_update_zone_size(tag, zone->tag_zone_index, + (long)elem_size); + } +#endif /* VM_MAX_TAG_ZONES */ + + TRACE_MACHLEAKS(ZALLOC_CODE, ZALLOC_CODE_2, elem_size, addr); + DTRACE_VM2(zalloc, zone_t, zone, void*, addr); + if (freemag) { + zone_magazine_free(freemag); + } + return (void *)addr; +} + +#if CONFIG_GZALLOC +/*! + * @function zalloc_gz + * + * @brief + * Performs allocations for zones using gzalloc. + * + * @discussion + * This function is noinline so that it doesn't affect the codegen + * of the fastpath. + */ +__attribute__((noinline)) +static void * +zalloc_gz(zone_t zone, zone_stats_t zstats, zalloc_flags_t flags) +{ + vm_offset_t addr = gzalloc_alloc(zone, zstats, flags); + return zalloc_return(zone, zone_element_encode(addr, 0, ZPM_AUTO), + flags, zone_elem_size(zone), NULL); +} +#endif /* CONFIG_GZALLOC */ + +static void * +zalloc_item_fast(zone_t zone, zone_stats_t zstats, zalloc_flags_t flags) +{ + vm_size_t esize = zone_elem_size(zone); + zone_element_t ze; + + zalloc_import(zone, &ze, 1); + zone_elems_free_sub(zone, 1); + zpercpu_get(zstats)->zs_mem_allocated += esize; + zone_unlock(zone); + + return zalloc_return(zone, ze, flags, esize, NULL); +} + +/*! + * @function zalloc_item_slow + * + * @brief + * Performs allocations when the zone is out of elements. + * + * @discussion + * This function might drop the lock and reenable preemption, + * which means the per-CPU caching layer or recirculation depot + * might have received elements. + */ +__attribute__((noinline)) +static void * +zalloc_item_slow(zone_t zone, zone_stats_t zstats, zalloc_flags_t flags) +{ + if (zone->z_replenishes) { + zone_replenish_locked(zone); + } else { + if ((flags & Z_NOWAIT) == 0) { + zone_expand_locked(zone, flags, zalloc_needs_refill); + } + if (flags & (Z_NOWAIT | Z_NOPAGEWAIT)) { + zone_expand_async_schedule_if_needed(zone); + } + if (__improbable(zone->z_elems_free == 0)) { + zone_unlock(zone); + if (__improbable(flags & Z_NOFAIL)) { + zone_nofail_panic(zone); + } + DTRACE_VM2(zalloc, zone_t, zone, void*, NULL); + return NULL; + } + } + + /* + * We might have changed core or got preempted/blocked while expanding + * the zone. Allocating from the zone when the recirculation depot + * is not empty is not allowed. + * + * It will be rare but possible for the depot to refill while we were + * waiting for pages. If that happens we need to start over. + */ + if (!STAILQ_EMPTY(&zone->z_recirc)) { + zone_unlock(zone); + return zalloc_ext(zone, zstats, flags); + } + + return zalloc_item_fast(zone, zstats, flags); +} + +/*! + * @function zalloc_item + * + * @brief + * Performs allocations when zone caching is off. + * + * @discussion + * This function calls @c zalloc_item_slow() when refilling the zone + * is needed, or @c zalloc_item_fast() if the zone has enough free elements. + */ +static void * +zalloc_item(zone_t zone, zone_stats_t zstats, zalloc_flags_t flags) +{ + zone_lock_check_contention(zone, NULL); + + /* + * When we commited to the zalloc_item() path, + * zone caching might have been flipped/enabled. + * + * If we got preempted for long enough, the recirculation layer + * can have been populated, and allocating from the zone would be + * incorrect. + * + * So double check for this extremely rare race here. + */ + if (__improbable(!STAILQ_EMPTY(&zone->z_recirc))) { + zone_unlock(zone); + return zalloc_ext(zone, zstats, flags); + } + + if (__improbable(zone->z_elems_free <= zone->z_elems_rsv)) { + return zalloc_item_slow(zone, zstats, flags); + } + + return zalloc_item_fast(zone, zstats, flags); +} + +static void * +zalloc_cached_fast(zone_t zone, zone_stats_t zstats, zalloc_flags_t flags, + zone_cache_t cache, zone_magazine_t freemag) +{ + vm_offset_t esize = zone_elem_size(zone); + zone_element_t ze; + uint32_t index; + + index = --cache->zc_alloc_cur; + if (index >= zc_mag_size()) { + zone_accounting_panic(zone, "zc_alloc_cur wrap around"); + } + ze = cache->zc_alloc_elems[index]; + cache->zc_alloc_elems[index].ze_value = 0; + + zpercpu_get(zstats)->zs_mem_allocated += esize; + enable_preemption(); + + if (zone_meta_is_free(zone_meta_from_element(ze), ze)) { + zone_meta_double_free_panic(zone, ze, __func__); + } + + return zalloc_return(zone, ze, flags, esize, freemag); +} + +static void * +zalloc_cached_from_depot(zone_t zone, zone_stats_t zstats, zalloc_flags_t flags, + zone_cache_t cache, zone_cache_t depot, zone_magazine_t mag) +{ + STAILQ_REMOVE_HEAD(&depot->zc_depot, zm_link); + if (depot->zc_depot_cur-- == 0) { + zone_accounting_panic(zone, "zc_depot_cur wrap-around"); + } + zone_depot_unlock_nopreempt(depot); + + mag = zone_magazine_replace(&cache->zc_alloc_cur, + &cache->zc_alloc_elems, mag); + + z_debug_assert(cache->zc_alloc_cur == zc_mag_size()); + z_debug_assert(mag->zm_cur == 0); + + if (zone == zc_magazine_zone) { + enable_preemption(); + bzero(mag, zone_elem_size(zone)); + return mag; + } + + return zalloc_cached_fast(zone, zstats, flags, cache, mag); +} + +__attribute__((noinline)) +static void * +zalloc_cached_slow(zone_t zone, zone_stats_t zstats, zalloc_flags_t flags, + zone_cache_t cache) +{ + zone_magazine_t mag = NULL; + struct zone_depot mags = STAILQ_HEAD_INITIALIZER(mags); + + /* + * Try to allocate from our local depot, if there's one. + */ + if (STAILQ_FIRST(&cache->zc_depot)) { + zone_depot_lock_nopreempt(cache); + + if ((mag = STAILQ_FIRST(&cache->zc_depot)) != NULL) { + return zalloc_cached_from_depot(zone, zstats, flags, + cache, cache, mag); + } + + zone_depot_unlock_nopreempt(cache); + } + + zone_lock_nopreempt_check_contention(zone, cache); + + /* + * If the recirculation depot is empty, we'll need to import. + * The system is tuned for this to be extremely rare. + */ + if (__improbable(STAILQ_EMPTY(&zone->z_recirc))) { + uint16_t n_elems = zc_mag_size(); + + if (zone->z_elems_free < n_elems + zone->z_elems_rsv / 2 && + os_sub_overflow(zone->z_elems_free, + zone->z_elems_rsv / 2, &n_elems)) { + n_elems = 0; + } + + z_debug_assert(n_elems <= zc_mag_size()); + + if (__improbable(n_elems == 0)) { + /* + * If importing elements would deplete the zone, + * call zalloc_item_slow() + */ + return zalloc_item_slow(zone, zstats, flags); + } + + if (__improbable(zone_caching_disabled)) { + if (__improbable(zone_caching_disabled < 0)) { + /* + * In the first 10s after boot, mess with + * the scan position in order to make early + * allocations patterns less predictible. + */ + zone_early_scramble_rr(zone, zstats); + } + return zalloc_item_fast(zone, zstats, flags); + } + + zalloc_import(zone, cache->zc_alloc_elems, n_elems); + + cache->zc_alloc_cur = n_elems; + zone_elems_free_sub(zone, n_elems); + + zone_unlock_nopreempt(zone); + + return zalloc_cached_fast(zone, zstats, flags, cache, NULL); + } + + uint16_t n_mags = 0; + + /* + * If the recirculation depot has elements, then try to fill + * the local per-cpu depot to (1 / zc_recirc_denom) + */ + do { + mag = STAILQ_FIRST(&zone->z_recirc); + STAILQ_REMOVE_HEAD(&zone->z_recirc, zm_link); + STAILQ_INSERT_TAIL(&mags, mag, zm_link); + n_mags++; + + for (uint16_t i = 0; i < zc_mag_size(); i++) { + zone_element_t e = mag->zm_elems[i]; + + if (!zone_meta_mark_used(zone_meta_from_element(e), e)) { + zone_meta_double_free_panic(zone, e, __func__); + } + } + } while (!STAILQ_EMPTY(&zone->z_recirc) && + zc_recirc_denom * n_mags * zc_mag_size() <= cache->zc_depot_max); + + zone_elems_free_sub(zone, n_mags * zc_mag_size()); + zone_counter_sub(zone, z_recirc_cur, n_mags); + + zone_unlock_nopreempt(zone); + + /* + * And then incorporate everything into our per-cpu layer. + */ + mag = STAILQ_FIRST(&mags); + STAILQ_REMOVE_HEAD(&mags, zm_link); + mag = zone_magazine_replace(&cache->zc_alloc_cur, + &cache->zc_alloc_elems, mag); + z_debug_assert(cache->zc_alloc_cur == zc_mag_size()); + z_debug_assert(mag->zm_cur == 0); + + if (--n_mags > 0) { + zone_depot_lock_nopreempt(cache); + cache->zc_depot_cur += n_mags; + STAILQ_CONCAT(&cache->zc_depot, &mags); + zone_depot_unlock_nopreempt(cache); + } + + return zalloc_cached_fast(zone, zstats, flags, cache, mag); +} + +/*! + * @function zalloc_cached + * + * @brief + * Performs allocations when zone caching is on. + * + * @discussion + * This function calls @c zalloc_cached_fast() when the caches have elements + * ready. + * + * Else it will call @c zalloc_cached_slow() so that the cache is refilled, + * which might switch to the @c zalloc_item_slow() track when the backing zone + * needs to be refilled. + */ +static void * +zalloc_cached(zone_t zone, zone_stats_t zstats, zalloc_flags_t flags) +{ + zone_cache_t cache; + + disable_preemption(); + cache = zpercpu_get(zone->z_pcpu_cache); + + if (cache->zc_alloc_cur == 0) { + if (__improbable(cache->zc_free_cur == 0)) { + return zalloc_cached_slow(zone, zstats, flags, cache); + } + zone_cache_swap_magazines(cache); + } + + return zalloc_cached_fast(zone, zstats, flags, cache, NULL); +} + +/*! + * @function zalloc_ext + * + * @brief + * The core implementation of @c zalloc(), @c zalloc_flags(), @c zalloc_percpu(). + */ +void * +zalloc_ext(zone_t zone, zone_stats_t zstats, zalloc_flags_t flags) +{ + /* + * KASan uses zalloc() for fakestack, which can be called anywhere. + * However, we make sure these calls can never block. + */ + assert(zone->kasan_fakestacks || + ml_get_interrupts_enabled() || + ml_is_quiescing() || + debug_mode_active() || + startup_phase < STARTUP_SUB_EARLY_BOOT); + + /* + * Make sure Z_NOFAIL was not obviously misused + */ + if (zone->z_replenishes) { + assert((flags & (Z_NOWAIT | Z_NOPAGEWAIT)) == 0); + } else if (flags & Z_NOFAIL) { + assert(!zone->exhaustible && + (flags & (Z_NOWAIT | Z_NOPAGEWAIT)) == 0); + } + +#if CONFIG_GZALLOC + if (__improbable(zone->gzalloc_tracked)) { + return zalloc_gz(zone, zstats, flags); + } +#endif /* CONFIG_GZALLOC */ + + if (zone->z_pcpu_cache) { + return zalloc_cached(zone, zstats, flags); + } + + return zalloc_item(zone, zstats, flags); +} + +void * +zalloc(union zone_or_view zov) +{ + return zalloc_flags(zov, Z_WAITOK); +} + +void * +zalloc_noblock(union zone_or_view zov) +{ + return zalloc_flags(zov, Z_NOWAIT); +} + +void * +zalloc_flags(union zone_or_view zov, zalloc_flags_t flags) +{ + zone_t zone = zov.zov_view->zv_zone; + zone_stats_t zstats = zov.zov_view->zv_stats; + assert(!zone->z_percpu); + return zalloc_ext(zone, zstats, flags); +} + +void * +zalloc_percpu(union zone_or_view zov, zalloc_flags_t flags) +{ + zone_t zone = zov.zov_view->zv_zone; + zone_stats_t zstats = zov.zov_view->zv_stats; + assert(zone->z_percpu); + return (void *)__zpcpu_mangle(zalloc_ext(zone, zstats, flags)); +} + +static void * +_zalloc_permanent(zone_t zone, vm_size_t size, vm_offset_t mask) +{ + struct zone_page_metadata *page_meta; + vm_offset_t offs, addr; + zone_pva_t pva; + + assert(ml_get_interrupts_enabled() || + ml_is_quiescing() || + debug_mode_active() || + startup_phase < STARTUP_SUB_EARLY_BOOT); + + size = (size + mask) & ~mask; + assert(size <= PAGE_SIZE); + + zone_lock(zone); + assert(zone->z_self == zone); + + for (;;) { + pva = zone->z_pageq_partial; + while (!zone_pva_is_null(pva)) { + page_meta = zone_pva_to_meta(pva); + if (page_meta->zm_bump + size <= PAGE_SIZE) { + goto found; + } + pva = page_meta->zm_page_next; + } + + zone_expand_locked(zone, Z_WAITOK, NULL); + } + +found: + offs = (uint16_t)((page_meta->zm_bump + mask) & ~mask); + page_meta->zm_bump = (uint16_t)(offs + size); + page_meta->zm_alloc_size += size; + zone->z_elems_free -= size; + zpercpu_get(zone->z_stats)->zs_mem_allocated += size; + + if (page_meta->zm_alloc_size >= PAGE_SIZE - sizeof(vm_offset_t)) { + zone_meta_requeue(zone, &zone->z_pageq_full, page_meta); + } + + zone_unlock(zone); + + addr = offs + zone_pva_to_addr(pva); + + DTRACE_VM2(zalloc, zone_t, zone, void*, addr); + return (void *)addr; +} + +static void * +_zalloc_permanent_large(size_t size, vm_offset_t mask) +{ + kern_return_t kr; + vm_offset_t addr; + + kr = kernel_memory_allocate(kernel_map, &addr, size, mask, + KMA_KOBJECT | KMA_PERMANENT | KMA_ZERO, + VM_KERN_MEMORY_KALLOC); + if (kr != 0) { + panic("zalloc_permanent: unable to allocate %zd bytes (%d)", + size, kr); + } + return (void *)addr; +} + +void * +zalloc_permanent(vm_size_t size, vm_offset_t mask) +{ + if (size <= PAGE_SIZE) { + zone_t zone = &zone_array[ZONE_ID_PERMANENT]; + return _zalloc_permanent(zone, size, mask); + } + return _zalloc_permanent_large(size, mask); +} + +void * +zalloc_percpu_permanent(vm_size_t size, vm_offset_t mask) +{ + zone_t zone = &zone_array[ZONE_ID_PERCPU_PERMANENT]; + return (void *)__zpcpu_mangle(_zalloc_permanent(zone, size, mask)); +} + +/*! @} */ +#endif /* !ZALLOC_TEST */ +#pragma mark zone GC / trimming +#if !ZALLOC_TEST + +static thread_call_data_t zone_defrag_callout; + +static void +zone_reclaim_chunk(zone_t z, struct zone_page_metadata *meta, uint32_t free_count) +{ + vm_address_t page_addr; + vm_size_t size_to_free; + uint32_t bitmap_ref; + uint32_t page_count; + bool sequester = z->z_va_sequester && !z->z_destroyed; + + zone_meta_queue_pop_native(z, &z->z_pageq_empty, &page_addr); + + page_count = meta->zm_chunk_len; + + if (meta->zm_alloc_size) { + zone_metadata_corruption(z, meta, "alloc_size"); + } + if (z->z_percpu) { + if (page_count != 1) { + zone_metadata_corruption(z, meta, "page_count"); + } + size_to_free = ptoa(z->z_chunk_pages); + os_atomic_sub(&zones_phys_page_mapped_count, + z->z_chunk_pages, relaxed); + } else { + if (page_count > z->z_chunk_pages) { + zone_metadata_corruption(z, meta, "page_count"); + } + if (page_count < z->z_chunk_pages) { + /* Dequeue non populated VA from z_pageq_va */ + zone_meta_remqueue(z, meta + page_count); + } + size_to_free = ptoa(page_count); + os_atomic_sub(&zones_phys_page_mapped_count, page_count, relaxed); + } + + zone_counter_sub(z, z_elems_free, free_count); + zone_counter_sub(z, z_elems_avail, free_count); + zone_counter_sub(z, z_wired_empty, page_count); + zone_counter_sub(z, z_wired_cur, page_count); + if (z->z_elems_free_min < free_count) { + z->z_elems_free_min = 0; + } else { + z->z_elems_free_min -= free_count; + } + if (z->z_elems_free_max < free_count) { + z->z_elems_free_max = 0; + } else { + z->z_elems_free_max -= free_count; + } + + bitmap_ref = 0; + if (sequester) { + if (meta->zm_inline_bitmap) { + for (int i = 0; i < meta->zm_chunk_len; i++) { + meta[i].zm_bitmap = 0; + } + } else { + bitmap_ref = meta->zm_bitmap; + meta->zm_bitmap = 0; + } + meta->zm_chunk_len = 0; + } else { + if (!meta->zm_inline_bitmap) { + bitmap_ref = meta->zm_bitmap; + } + zone_counter_sub(z, z_va_cur, z->z_percpu ? 1 : z->z_chunk_pages); + bzero(meta, sizeof(*meta) * z->z_chunk_pages); + } + + zone_unlock(z); + + if (bitmap_ref) { + zone_bits_free(bitmap_ref); + } + + /* Free the pages for metadata and account for them */ +#if KASAN_ZALLOC + kasan_poison_range(page_addr, size_to_free, ASAN_VALID); +#endif +#if VM_MAX_TAG_ZONES + if (z->tags) { + ztMemoryRemove(z, page_addr, size_to_free); + } +#endif /* VM_MAX_TAG_ZONES */ + + if (sequester) { + kernel_memory_depopulate(zone_submap(z), page_addr, + size_to_free, KMA_KOBJECT, VM_KERN_MEMORY_ZONE); + } else { + kmem_free(zone_submap(z), page_addr, ptoa(z->z_chunk_pages)); + } + + /* + * Freeing memory sometimes needs some (for example vm map entries + * to represent holes). + * + * If there are any active replenish threads, we need to let them work + * while we hold no locks. Only do so right after we just freed memory + * once however to give them even more chances to find fresh pages. + */ + zone_replenish_wait_if_needed(); + + thread_yield_to_preemption(); + + zone_lock(z); + + if (sequester) { + zone_meta_queue_push(z, &z->z_pageq_va, meta); + } +} + +static uint16_t +zone_reclaim_elements(zone_t z, uint16_t *count, zone_element_t *elems) +{ + uint16_t n = *count; + + z_debug_assert(n <= zc_mag_size()); + + for (uint16_t i = 0; i < n; i++) { + zone_element_t ze = elems[i]; + elems[i].ze_value = 0; + zfree_drop(z, zone_element_validate(z, ze), ze, false); + } + + *count = 0; + return n; +} + +static uint16_t +zone_reclaim_recirc_magazine(zone_t z, struct zone_depot *mags) +{ + zone_magazine_t mag = STAILQ_FIRST(&z->z_recirc); + + STAILQ_REMOVE_HEAD(&z->z_recirc, zm_link); + STAILQ_INSERT_TAIL(mags, mag, zm_link); + zone_counter_sub(z, z_recirc_cur, 1); + + z_debug_assert(mag->zm_cur == zc_mag_size()); + + for (uint16_t i = 0; i < zc_mag_size(); i++) { + zone_element_t ze = mag->zm_elems[i]; + mag->zm_elems[i].ze_value = 0; + zfree_drop(z, zone_element_validate(z, ze), ze, true); + } + + mag->zm_cur = 0; + + return zc_mag_size(); +} + +static void +zone_depot_trim(zone_cache_t zc, struct zone_depot *head) +{ + zone_magazine_t mag; + + if (zc->zc_depot_cur == 0 || + 2 * (zc->zc_depot_cur + 1) * zc_mag_size() <= zc->zc_depot_max) { + return; + } + + zone_depot_lock(zc); + + while (zc->zc_depot_cur && + 2 * (zc->zc_depot_cur + 1) * zc_mag_size() > zc->zc_depot_max) { + mag = STAILQ_FIRST(&zc->zc_depot); + STAILQ_REMOVE_HEAD(&zc->zc_depot, zm_link); + STAILQ_INSERT_TAIL(head, mag, zm_link); + zc->zc_depot_cur--; + } + + zone_depot_unlock(zc); +} + +__enum_decl(zone_reclaim_mode_t, uint32_t, { + ZONE_RECLAIM_TRIM, + ZONE_RECLAIM_DRAIN, + ZONE_RECLAIM_DESTROY, +}); + +/*! + * @function zone_reclaim + * + * @brief + * Drains or trim the zone. + * + * @discussion + * Draining the zone will free it from all its elements. + * + * Trimming the zone tries to respect the working set size, and avoids draining + * the depot when it's not necessary. + * + * @param z The zone to reclaim from + * @param mode The purpose of this reclaim. + */ +static void +zone_reclaim(zone_t z, zone_reclaim_mode_t mode) +{ + struct zone_depot mags = STAILQ_HEAD_INITIALIZER(mags); + zone_magazine_t mag, tmp; + + zone_lock(z); + + if (mode == ZONE_RECLAIM_DESTROY) { + if (!z->z_destructible || z->z_pcpu_cache || + z->z_elems_rsv || z->z_allows_foreign) { + panic("zdestroy: Zone %s%s isn't destructible", + zone_heap_name(z), z->z_name); + } + + if (!z->z_self || z->z_expander || z->z_expander_vm_priv || + z->z_async_refilling || z->z_expanding_wait) { + panic("zdestroy: Zone %s%s in an invalid state for destruction", + zone_heap_name(z), z->z_name); + } + +#if !KASAN_ZALLOC + /* + * Unset the valid bit. We'll hit an assert failure on further + * operations on this zone, until zinit() is called again. + * + * Leave the zone valid for KASan as we will see zfree's on + * quarantined free elements even after the zone is destroyed. + */ + z->z_self = NULL; +#endif + z->z_destroyed = true; + } else if (z->z_destroyed) { + return zone_unlock(z); + } else if (z->z_replenishes && z->z_async_refilling) { + /* + * If the zone is replenishing, leave it alone. + */ + return zone_unlock(z); + } + + if (z->z_pcpu_cache) { + if (mode != ZONE_RECLAIM_TRIM) { + zpercpu_foreach(zc, z->z_pcpu_cache) { + zc->zc_depot_max /= 2; + } + } else { + zpercpu_foreach(zc, z->z_pcpu_cache) { + if (zc->zc_depot_max > 0) { + zc->zc_depot_max--; + } + } + } + + zone_unlock(z); + + if (mode == ZONE_RECLAIM_TRIM) { + zpercpu_foreach(zc, z->z_pcpu_cache) { + zone_depot_trim(zc, &mags); + } + } else { + zpercpu_foreach(zc, z->z_pcpu_cache) { + zone_depot_lock(zc); + STAILQ_CONCAT(&mags, &zc->zc_depot); + zc->zc_depot_cur = 0; + zone_depot_unlock(zc); + } + } + + zone_lock(z); + + uint32_t freed = 0; + + STAILQ_FOREACH(mag, &mags, zm_link) { + freed += zone_reclaim_elements(z, + &mag->zm_cur, mag->zm_elems); + + if (freed >= zc_free_batch_size) { + z->z_elems_free_min += freed; + z->z_elems_free_max += freed; + z->z_elems_free += freed; + zone_unlock(z); + thread_yield_to_preemption(); + zone_lock(z); + freed = 0; + } + } + + if (mode == ZONE_RECLAIM_DESTROY) { + zpercpu_foreach(zc, z->z_pcpu_cache) { + freed += zone_reclaim_elements(z, + &zc->zc_alloc_cur, zc->zc_alloc_elems); + freed += zone_reclaim_elements(z, + &zc->zc_free_cur, zc->zc_free_elems); + } + + z->z_elems_free_wss = 0; + z->z_elems_free_min = 0; + z->z_elems_free_max = 0; + z->z_contention_cur = 0; + z->z_contention_wma = 0; + } else { + z->z_elems_free_min += freed; + z->z_elems_free_max += freed; + } + z->z_elems_free += freed; + } + + for (;;) { + struct zone_page_metadata *meta; + uint32_t count, goal, freed = 0; + + goal = z->z_elems_rsv; + if (mode == ZONE_RECLAIM_TRIM) { + /* + * When trimming, only free elements in excess + * of the working set estimate. + * + * However if we are in a situation where the working + * set estimate is clearly growing, ignore the estimate + * as the next working set update will grow it and + * we want to avoid churn. + */ + goal = MAX(goal, MAX(z->z_elems_free_wss, + z->z_elems_free - z->z_elems_free_min)); + + /* + * Add some slop to account for "the last partial chunk in flight" + * so that we do not deplete the recirculation depot too harshly. + */ + goal += z->z_chunk_elems / 2; + } + + if (z->z_elems_free <= goal) { + break; + } + + /* + * If we're above target, but we have no free page, then drain + * the recirculation depot until we get a free chunk or exhaust + * the depot. + * + * This is rather abrupt but also somehow will reduce + * fragmentation anyway, and the zone code will import + * over time anyway. + */ + while (z->z_recirc_cur) { + if (z->z_recirc_cur * zc_mag_size() <= goal && + !zone_pva_is_null(z->z_pageq_empty)) { + break; + } + if (freed >= zc_free_batch_size) { + zone_unlock(z); + thread_yield_to_preemption(); + zone_lock(z); + freed = 0; + /* we dropped the lock, needs to reassess */ + continue; + } + freed += zone_reclaim_recirc_magazine(z, &mags); + } + + if (zone_pva_is_null(z->z_pageq_empty)) { + break; + } + + meta = zone_pva_to_meta(z->z_pageq_empty); + count = (uint32_t)ptoa(meta->zm_chunk_len) / zone_elem_size(z); + + if (z->z_elems_free - count < goal) { + break; + } + + zone_reclaim_chunk(z, meta, count); + } + + zone_unlock(z); + + STAILQ_FOREACH_SAFE(mag, &mags, zm_link, tmp) { + zone_magazine_free(mag); + } +} + +static void +zone_reclam_all(zone_reclaim_mode_t mode) +{ + /* + * Start with zones with VA sequester since depopulating + * pages will not need to allocate vm map entries for holes, + * which will give memory back to the system faster. + */ + zone_foreach(z) { + if (z == zc_magazine_zone) { + continue; + } + if (z->z_va_sequester && z->collectable) { + zone_reclaim(z, mode); + } + } + + zone_foreach(z) { + if (z == zc_magazine_zone) { + continue; + } + if (!z->z_va_sequester && z->collectable) { + zone_reclaim(z, mode); + } + } + + zone_reclaim(zc_magazine_zone, mode); +} + +void +zone_gc(zone_gc_level_t level) +{ + zone_reclaim_mode_t mode; + + switch (level) { + case ZONE_GC_TRIM: + mode = ZONE_RECLAIM_TRIM; + break; + case ZONE_GC_DRAIN: + mode = ZONE_RECLAIM_DRAIN; + break; + case ZONE_GC_JETSAM: + kill_process_in_largest_zone(); + mode = ZONE_RECLAIM_TRIM; + break; + } + + current_thread()->options |= TH_OPT_ZONE_PRIV; + lck_mtx_lock(&zone_gc_lock); + + zone_reclam_all(mode); + + if (level == ZONE_GC_JETSAM && zone_map_nearing_exhaustion()) { + /* + * If we possibly killed a process, but we're still critical, + * we need to drain harder. + */ + zone_reclam_all(ZONE_RECLAIM_DRAIN); + } + + lck_mtx_unlock(&zone_gc_lock); + current_thread()->options &= ~TH_OPT_ZONE_PRIV; +} + +void +zone_gc_trim(void) +{ + zone_gc(ZONE_GC_TRIM); +} + +void +zone_gc_drain(void) +{ + zone_gc(ZONE_GC_DRAIN); +} + +static bool +zone_defrag_needed(zone_t z) +{ + uint32_t recirc_size = z->z_recirc_cur * zc_mag_size(); + + if (recirc_size <= z->z_chunk_elems / 2) { + return false; + } + return recirc_size * zc_defrag_ratio > z->z_elems_free_wss * 100; +} + +/*! + * @function zone_defrag_async + * + * @brief + * Resize the recirculation depot to match the working set size. + * + * @discussion + * When zones grow very large due to a spike in usage, and then some of those + * elements get freed, the elements in magazines in the recirculation depot + * are in no particular order. + * + * In order to control fragmentation, we need to detect "empty" pages so that + * they get onto the @c z_pageq_empty freelist, so that allocations re-pack + * naturally. + * + * This is done very gently, never in excess of the working set and some slop. + */ +static void +zone_defrag_async(__unused thread_call_param_t p0, __unused thread_call_param_t p1) +{ + zone_foreach(z) { + struct zone_depot mags = STAILQ_HEAD_INITIALIZER(mags); + zone_magazine_t mag, tmp; + uint32_t freed = 0, goal = 0; + + if (!z->collectable || !zone_defrag_needed(z)) { + continue; + } + + zone_lock(z); + + goal = z->z_elems_free_wss + z->z_chunk_elems / 2 + + zc_mag_size() - 1; + + while (z->z_recirc_cur * zc_mag_size() > goal) { + if (freed >= zc_free_batch_size) { + zone_unlock(z); + thread_yield_to_preemption(); + zone_lock(z); + freed = 0; + /* we dropped the lock, needs to reassess */ + continue; + } + freed += zone_reclaim_recirc_magazine(z, &mags); + } + + zone_unlock(z); + + STAILQ_FOREACH_SAFE(mag, &mags, zm_link, tmp) { + zone_magazine_free(mag); + } + } +} + +void +compute_zone_working_set_size(__unused void *param) +{ + uint32_t zc_auto = zc_auto_threshold; + bool kick_defrag = false; + + /* + * Keep zone caching disabled until the first proc is made. + */ + if (__improbable(zone_caching_disabled < 0)) { + return; + } + + zone_caching_disabled = vm_pool_low(); +#if ZALLOC_EARLY_GAPS + zone_cleanup_early_gaps_if_needed(); +#endif + + if (os_mul_overflow(zc_auto, Z_CONTENTION_WMA_UNIT, &zc_auto)) { + zc_auto = 0; + } + + zone_foreach(z) { + uint32_t wma; + bool needs_caching = false; + + if (z->z_self != z) { + continue; + } + + zone_lock(z); + + wma = z->z_elems_free_max - z->z_elems_free_min; + wma = (3 * wma + z->z_elems_free_wss) / 4; + z->z_elems_free_max = z->z_elems_free_min = z->z_elems_free; + z->z_elems_free_wss = wma; + + if (!kick_defrag && zone_defrag_needed(z)) { + kick_defrag = true; + } + + /* fixed point decimal of contentions per second */ + wma = z->z_contention_cur * Z_CONTENTION_WMA_UNIT / + ZONE_WSS_UPDATE_PERIOD; + z->z_contention_cur = 0; + z->z_contention_wma = (3 * wma + z->z_contention_wma) / 4; + + /* + * If the zone seems to be very quiet, + * gently lower its cpu-local depot size. + */ + if (z->z_pcpu_cache && wma < Z_CONTENTION_WMA_UNIT / 2 && + z->z_contention_wma < Z_CONTENTION_WMA_UNIT / 2) { + zpercpu_foreach(zc, z->z_pcpu_cache) { + if (zc->zc_depot_max > zc_mag_size()) { + zc->zc_depot_max--; + } + } + } + + /* + * If the zone has been contending like crazy for two periods, + * and is eligible, maybe it's time to enable caching. + */ + if (!z->z_nocaching && !z->z_pcpu_cache && !z->exhaustible && + zc_auto && z->z_contention_wma >= zc_auto && wma >= zc_auto) { + needs_caching = true; + } + + zone_unlock(z); + + if (needs_caching) { + zone_enable_caching(z); + } + } + + if (kick_defrag) { + thread_call_enter(&zone_defrag_callout); + } +} + +#endif /* !ZALLOC_TEST */ +#pragma mark vm integration, MIG routines +#if !ZALLOC_TEST + +/* + * Creates a vm_map_copy_t to return to the caller of mach_* MIG calls + * requesting zone information. + * Frees unused pages towards the end of the region, and zero'es out unused + * space on the last page. + */ +static vm_map_copy_t +create_vm_map_copy( + vm_offset_t start_addr, + vm_size_t total_size, + vm_size_t used_size) +{ + kern_return_t kr; + vm_offset_t end_addr; + vm_size_t free_size; + vm_map_copy_t copy; + + if (used_size != total_size) { + end_addr = start_addr + used_size; + free_size = total_size - (round_page(end_addr) - start_addr); + + if (free_size >= PAGE_SIZE) { + kmem_free(ipc_kernel_map, + round_page(end_addr), free_size); + } + bzero((char *) end_addr, round_page(end_addr) - end_addr); + } + + kr = vm_map_copyin(ipc_kernel_map, (vm_map_address_t)start_addr, + (vm_map_size_t)used_size, TRUE, ©); + assert(kr == KERN_SUCCESS); + + return copy; +} + +static boolean_t +get_zone_info( + zone_t z, + mach_zone_name_t *zn, + mach_zone_info_t *zi) +{ + struct zone zcopy; + vm_size_t cached = 0; + + assert(z != ZONE_NULL); + zone_lock(z); + if (!z->z_self) { + zone_unlock(z); + return FALSE; + } + zcopy = *z; + if (z->z_pcpu_cache) { + zpercpu_foreach(zc, z->z_pcpu_cache) { + cached += zc->zc_alloc_cur + zc->zc_free_cur; + cached += zc->zc_depot_cur * zc_mag_size(); + } + } + zone_unlock(z); + + if (zn != NULL) { + /* + * Append kalloc heap name to zone name (if zone is used by kalloc) + */ + char temp_zone_name[MAX_ZONE_NAME] = ""; + snprintf(temp_zone_name, MAX_ZONE_NAME, "%s%s", + zone_heap_name(z), z->z_name); + + /* assuming here the name data is static */ + (void) __nosan_strlcpy(zn->mzn_name, temp_zone_name, + strlen(temp_zone_name) + 1); + } + + if (zi != NULL) { + *zi = (mach_zone_info_t) { + .mzi_count = zone_count_allocated(&zcopy) - cached, + .mzi_cur_size = ptoa_64(zone_scale_for_percpu(&zcopy, zcopy.z_wired_cur)), + // max_size for zprint is now high-watermark of pages used + .mzi_max_size = ptoa_64(zone_scale_for_percpu(&zcopy, zcopy.z_wired_hwm)), + .mzi_elem_size = zone_scale_for_percpu(&zcopy, zcopy.z_elem_size), + .mzi_alloc_size = ptoa_64(zcopy.z_chunk_pages), + .mzi_exhaustible = (uint64_t)zcopy.exhaustible, + }; + zpercpu_foreach(zs, zcopy.z_stats) { + zi->mzi_sum_size += zs->zs_mem_allocated; + } + if (zcopy.collectable) { + SET_MZI_COLLECTABLE_BYTES(zi->mzi_collectable, + ptoa_64(zone_scale_for_percpu(&zcopy, zcopy.z_wired_empty))); + SET_MZI_COLLECTABLE_FLAG(zi->mzi_collectable, TRUE); + } + } + + return TRUE; +} + +kern_return_t +task_zone_info( + __unused task_t task, + __unused mach_zone_name_array_t *namesp, + __unused mach_msg_type_number_t *namesCntp, + __unused task_zone_info_array_t *infop, + __unused mach_msg_type_number_t *infoCntp) +{ + return KERN_FAILURE; +} + +kern_return_t +mach_zone_info( + host_priv_t host, + mach_zone_name_array_t *namesp, + mach_msg_type_number_t *namesCntp, + mach_zone_info_array_t *infop, + mach_msg_type_number_t *infoCntp) +{ + return mach_memory_info(host, namesp, namesCntp, infop, infoCntp, NULL, NULL); +} + + +kern_return_t +mach_memory_info( + host_priv_t host, + mach_zone_name_array_t *namesp, + mach_msg_type_number_t *namesCntp, + mach_zone_info_array_t *infop, + mach_msg_type_number_t *infoCntp, + mach_memory_info_array_t *memoryInfop, + mach_msg_type_number_t *memoryInfoCntp) +{ + mach_zone_name_t *names; + vm_offset_t names_addr; + vm_size_t names_size; + + mach_zone_info_t *info; + vm_offset_t info_addr; + vm_size_t info_size; + + mach_memory_info_t *memory_info; + vm_offset_t memory_info_addr; + vm_size_t memory_info_size; + vm_size_t memory_info_vmsize; + unsigned int num_info; + + unsigned int max_zones, used_zones, i; + mach_zone_name_t *zn; + mach_zone_info_t *zi; + kern_return_t kr; + + uint64_t zones_collectable_bytes = 0; + + if (host == HOST_NULL) { + return KERN_INVALID_HOST; + } +#if CONFIG_DEBUGGER_FOR_ZONE_INFO + if (!PE_i_can_has_debugger(NULL)) { + return KERN_INVALID_HOST; + } +#endif + + /* + * We assume that zones aren't freed once allocated. + * We won't pick up any zones that are allocated later. + */ + + max_zones = os_atomic_load(&num_zones, relaxed); + + names_size = round_page(max_zones * sizeof *names); + kr = kmem_alloc_pageable(ipc_kernel_map, + &names_addr, names_size, VM_KERN_MEMORY_IPC); + if (kr != KERN_SUCCESS) { + return kr; + } + names = (mach_zone_name_t *) names_addr; + + info_size = round_page(max_zones * sizeof *info); + kr = kmem_alloc_pageable(ipc_kernel_map, + &info_addr, info_size, VM_KERN_MEMORY_IPC); + if (kr != KERN_SUCCESS) { + kmem_free(ipc_kernel_map, + names_addr, names_size); + return kr; + } + info = (mach_zone_info_t *) info_addr; + + zn = &names[0]; + zi = &info[0]; + + used_zones = max_zones; + for (i = 0; i < max_zones; i++) { + if (!get_zone_info(&(zone_array[i]), zn, zi)) { + used_zones--; + continue; + } + zones_collectable_bytes += GET_MZI_COLLECTABLE_BYTES(zi->mzi_collectable); + zn++; + zi++; + } + + *namesp = (mach_zone_name_t *) create_vm_map_copy(names_addr, names_size, used_zones * sizeof *names); + *namesCntp = used_zones; + + *infop = (mach_zone_info_t *) create_vm_map_copy(info_addr, info_size, used_zones * sizeof *info); + *infoCntp = used_zones; + + num_info = 0; + memory_info_addr = 0; + + if (memoryInfop && memoryInfoCntp) { + vm_map_copy_t copy; + num_info = vm_page_diagnose_estimate(); + memory_info_size = num_info * sizeof(*memory_info); + memory_info_vmsize = round_page(memory_info_size); + kr = kmem_alloc_pageable(ipc_kernel_map, + &memory_info_addr, memory_info_vmsize, VM_KERN_MEMORY_IPC); + if (kr != KERN_SUCCESS) { + return kr; + } + + kr = vm_map_wire_kernel(ipc_kernel_map, memory_info_addr, memory_info_addr + memory_info_vmsize, + VM_PROT_READ | VM_PROT_WRITE, VM_KERN_MEMORY_IPC, FALSE); + assert(kr == KERN_SUCCESS); + + memory_info = (mach_memory_info_t *) memory_info_addr; + vm_page_diagnose(memory_info, num_info, zones_collectable_bytes); + + kr = vm_map_unwire(ipc_kernel_map, memory_info_addr, memory_info_addr + memory_info_vmsize, FALSE); + assert(kr == KERN_SUCCESS); + + kr = vm_map_copyin(ipc_kernel_map, (vm_map_address_t)memory_info_addr, + (vm_map_size_t)memory_info_size, TRUE, ©); + assert(kr == KERN_SUCCESS); + + *memoryInfop = (mach_memory_info_t *) copy; + *memoryInfoCntp = num_info; + } + + return KERN_SUCCESS; +} + +kern_return_t +mach_zone_info_for_zone( + host_priv_t host, + mach_zone_name_t name, + mach_zone_info_t *infop) +{ + zone_t zone_ptr; + + if (host == HOST_NULL) { + return KERN_INVALID_HOST; + } +#if CONFIG_DEBUGGER_FOR_ZONE_INFO + if (!PE_i_can_has_debugger(NULL)) { + return KERN_INVALID_HOST; + } +#endif + + if (infop == NULL) { + return KERN_INVALID_ARGUMENT; + } + + zone_ptr = ZONE_NULL; + zone_foreach(z) { + /* + * Append kalloc heap name to zone name (if zone is used by kalloc) + */ + char temp_zone_name[MAX_ZONE_NAME] = ""; + snprintf(temp_zone_name, MAX_ZONE_NAME, "%s%s", + zone_heap_name(z), z->z_name); + + /* Find the requested zone by name */ + if (track_this_zone(temp_zone_name, name.mzn_name)) { + zone_ptr = z; + break; + } + } + + /* No zones found with the requested zone name */ + if (zone_ptr == ZONE_NULL) { + return KERN_INVALID_ARGUMENT; + } + + if (get_zone_info(zone_ptr, NULL, infop)) { + return KERN_SUCCESS; + } + return KERN_FAILURE; +} + +kern_return_t +mach_zone_info_for_largest_zone( + host_priv_t host, + mach_zone_name_t *namep, + mach_zone_info_t *infop) +{ + if (host == HOST_NULL) { + return KERN_INVALID_HOST; + } +#if CONFIG_DEBUGGER_FOR_ZONE_INFO + if (!PE_i_can_has_debugger(NULL)) { + return KERN_INVALID_HOST; + } +#endif + + if (namep == NULL || infop == NULL) { + return KERN_INVALID_ARGUMENT; + } + + if (get_zone_info(zone_find_largest(), namep, infop)) { + return KERN_SUCCESS; + } + return KERN_FAILURE; +} + +uint64_t +get_zones_collectable_bytes(void) +{ + uint64_t zones_collectable_bytes = 0; + mach_zone_info_t zi; + + zone_foreach(z) { + if (get_zone_info(z, NULL, &zi)) { + zones_collectable_bytes += + GET_MZI_COLLECTABLE_BYTES(zi.mzi_collectable); + } + } + + return zones_collectable_bytes; +} + +kern_return_t +mach_zone_get_zlog_zones( + host_priv_t host, + mach_zone_name_array_t *namesp, + mach_msg_type_number_t *namesCntp) +{ +#if ZONE_ENABLE_LOGGING + unsigned int max_zones, logged_zones, i; + kern_return_t kr; + zone_t zone_ptr; + mach_zone_name_t *names; + vm_offset_t names_addr; + vm_size_t names_size; + + if (host == HOST_NULL) { + return KERN_INVALID_HOST; + } + + if (namesp == NULL || namesCntp == NULL) { + return KERN_INVALID_ARGUMENT; + } + + max_zones = os_atomic_load(&num_zones, relaxed); + + names_size = round_page(max_zones * sizeof *names); + kr = kmem_alloc_pageable(ipc_kernel_map, + &names_addr, names_size, VM_KERN_MEMORY_IPC); + if (kr != KERN_SUCCESS) { + return kr; + } + names = (mach_zone_name_t *) names_addr; + + zone_ptr = ZONE_NULL; + logged_zones = 0; + for (i = 0; i < max_zones; i++) { + zone_t z = &(zone_array[i]); + assert(z != ZONE_NULL); + + /* Copy out the zone name if zone logging is enabled */ + if (z->zlog_btlog) { + get_zone_info(z, &names[logged_zones], NULL); + logged_zones++; + } + } + + *namesp = (mach_zone_name_t *) create_vm_map_copy(names_addr, names_size, logged_zones * sizeof *names); + *namesCntp = logged_zones; + + return KERN_SUCCESS; + +#else /* ZONE_ENABLE_LOGGING */ +#pragma unused(host, namesp, namesCntp) + return KERN_FAILURE; +#endif /* ZONE_ENABLE_LOGGING */ +} + +kern_return_t +mach_zone_get_btlog_records( + host_priv_t host, + mach_zone_name_t name, + zone_btrecord_array_t *recsp, + mach_msg_type_number_t *recsCntp) +{ +#if DEBUG || DEVELOPMENT + unsigned int numrecs = 0; + zone_btrecord_t *recs; + kern_return_t kr; + zone_t zone_ptr; + vm_offset_t recs_addr; + vm_size_t recs_size; + + if (host == HOST_NULL) { + return KERN_INVALID_HOST; + } + + if (recsp == NULL || recsCntp == NULL) { + return KERN_INVALID_ARGUMENT; + } + + zone_ptr = ZONE_NULL; + zone_foreach(z) { + /* + * Append kalloc heap name to zone name (if zone is used by kalloc) + */ + char temp_zone_name[MAX_ZONE_NAME] = ""; + snprintf(temp_zone_name, MAX_ZONE_NAME, "%s%s", + zone_heap_name(z), z->z_name); + + /* Find the requested zone by name */ + if (track_this_zone(temp_zone_name, name.mzn_name)) { + zone_ptr = z; + break; + } + } + + /* No zones found with the requested zone name */ + if (zone_ptr == ZONE_NULL) { + return KERN_INVALID_ARGUMENT; + } + + /* Logging not turned on for the requested zone */ + if (!DO_LOGGING(zone_ptr)) { + return KERN_FAILURE; + } + + /* Allocate memory for btlog records */ + numrecs = (unsigned int)(get_btlog_records_count(zone_ptr->zlog_btlog)); + recs_size = round_page(numrecs * sizeof *recs); + + kr = kmem_alloc_pageable(ipc_kernel_map, &recs_addr, recs_size, VM_KERN_MEMORY_IPC); + if (kr != KERN_SUCCESS) { + return kr; + } + + /* + * We will call get_btlog_records() below which populates this region while holding a spinlock + * (the btlog lock). So these pages need to be wired. + */ + kr = vm_map_wire_kernel(ipc_kernel_map, recs_addr, recs_addr + recs_size, + VM_PROT_READ | VM_PROT_WRITE, VM_KERN_MEMORY_IPC, FALSE); + assert(kr == KERN_SUCCESS); + + recs = (zone_btrecord_t *)recs_addr; + get_btlog_records(zone_ptr->zlog_btlog, recs, &numrecs); + + kr = vm_map_unwire(ipc_kernel_map, recs_addr, recs_addr + recs_size, FALSE); + assert(kr == KERN_SUCCESS); + + *recsp = (zone_btrecord_t *) create_vm_map_copy(recs_addr, recs_size, numrecs * sizeof *recs); + *recsCntp = numrecs; + + return KERN_SUCCESS; + +#else /* DEBUG || DEVELOPMENT */ +#pragma unused(host, name, recsp, recsCntp) + return KERN_FAILURE; +#endif /* DEBUG || DEVELOPMENT */ } -#endif /* CONFIG_ZLEAKS */ -/* These functions outside of CONFIG_ZLEAKS because they are also used in - * mbuf.c for mbuf leak-detection. This is why they lack the z_ prefix. - */ +#if DEBUG || DEVELOPMENT -/* "Thomas Wang's 32/64 bit mix functions." http://www.concentric.net/~Ttwang/tech/inthash.htm */ -uintptr_t -hash_mix(uintptr_t x) +kern_return_t +mach_memory_info_check(void) { -#ifndef __LP64__ - x += ~(x << 15); - x ^= (x >> 10); - x += (x << 3 ); - x ^= (x >> 6 ); - x += ~(x << 11); - x ^= (x >> 16); -#else - x += ~(x << 32); - x ^= (x >> 22); - x += ~(x << 13); - x ^= (x >> 8 ); - x += (x << 3 ); - x ^= (x >> 15); - x += ~(x << 27); - x ^= (x >> 31); -#endif - return x; -} + mach_memory_info_t * memory_info; + mach_memory_info_t * info; + unsigned int num_info; + vm_offset_t memory_info_addr; + kern_return_t kr; + size_t memory_info_size, memory_info_vmsize; + uint64_t top_wired, zonestotal, total; + + num_info = vm_page_diagnose_estimate(); + memory_info_size = num_info * sizeof(*memory_info); + memory_info_vmsize = round_page(memory_info_size); + kr = kmem_alloc(kernel_map, &memory_info_addr, memory_info_vmsize, VM_KERN_MEMORY_DIAG); + assert(kr == KERN_SUCCESS); -uint32_t -hashbacktrace(uintptr_t* bt, uint32_t depth, uint32_t max_size) -{ + memory_info = (mach_memory_info_t *) memory_info_addr; + vm_page_diagnose(memory_info, num_info, 0); - uintptr_t hash = 0; - uintptr_t mask = max_size - 1; + top_wired = total = zonestotal = 0; + zone_foreach(z) { + zonestotal += zone_size_wired(z); + } - while (depth) { - hash += bt[--depth]; + for (uint32_t idx = 0; idx < num_info; idx++) { + info = &memory_info[idx]; + if (!info->size) { + continue; + } + if (VM_KERN_COUNT_WIRED == info->site) { + top_wired = info->size; + } + if (VM_KERN_SITE_HIDE & info->flags) { + continue; + } + if (!(VM_KERN_SITE_WIRED & info->flags)) { + continue; + } + total += info->size; } + total += zonestotal; - hash = hash_mix(hash) & mask; + printf("vm_page_diagnose_check %qd of %qd, zones %qd, short 0x%qx\n", + total, top_wired, zonestotal, top_wired - total); - assert(hash < max_size); + kmem_free(kernel_map, memory_info_addr, memory_info_vmsize); - return (uint32_t) hash; + return kr; } -/* - * TODO: Determine how well distributed this is - * max_size must be a power of 2. i.e 0x10000 because 0x10000-1 is 0x0FFFF which is a great bitmask - */ -uint32_t -hashaddr(uintptr_t pt, uint32_t max_size) -{ - uintptr_t hash = 0; - uintptr_t mask = max_size - 1; +extern boolean_t(*volatile consider_buffer_cache_collect)(int); - hash = hash_mix(pt) & mask; +#endif /* DEBUG || DEVELOPMENT */ - assert(hash < max_size); +kern_return_t +mach_zone_force_gc( + host_t host) +{ + if (host == HOST_NULL) { + return KERN_INVALID_HOST; + } - return (uint32_t) hash; +#if DEBUG || DEVELOPMENT + /* Callout to buffer cache GC to drop elements in the apfs zones */ + if (consider_buffer_cache_collect != NULL) { + (void)(*consider_buffer_cache_collect)(0); + } + zone_gc(ZONE_GC_DRAIN); +#endif /* DEBUG || DEVELOPMENT */ + return KERN_SUCCESS; } -/* End of all leak-detection code */ -#pragma mark - - -#define ZONE_MAX_ALLOC_SIZE (32 * 1024) -#define ZONE_ALLOC_FRAG_PERCENT(alloc_size, ele_size) (((alloc_size % ele_size) * 100) / alloc_size) - -/* - * zinit initializes a new zone. The zone data structures themselves - * are stored in a zone, which is initially a static structure that - * is initialized by zone_init. - */ zone_t -zinit( - vm_size_t size, /* the size of an element */ - vm_size_t max, /* maximum memory to use */ - vm_size_t alloc, /* allocation size */ - const char *name) /* a name for the zone */ +zone_find_largest(void) { - zone_t z; + uint32_t largest_idx = 0; + vm_offset_t largest_size = zone_size_wired(&zone_array[0]); + + zone_index_foreach(i) { + vm_offset_t size = zone_size_wired(&zone_array[i]); + if (size > largest_size) { + largest_idx = i; + largest_size = size; + } + } - simple_lock(&all_zones_lock); - z = &(zone_array[zone_array_index]); - zone_array_index++; - assert(zone_array_index != MAX_ZONES); - simple_unlock(&all_zones_lock); + return &zone_array[largest_idx]; +} - /* Zone elements must fit both a next pointer and a backup pointer */ - vm_size_t minimum_element_size = sizeof(vm_offset_t) * 2; - if (size < minimum_element_size) - size = minimum_element_size; - - /* - * Round element size to a multiple of sizeof(pointer) - * This also enforces that allocations will be aligned on pointer boundaries - */ - size = ((size-1) + sizeof(vm_offset_t)) - - ((size-1) % sizeof(vm_offset_t)); - - if (alloc == 0) - alloc = PAGE_SIZE; - - alloc = round_page(alloc); - max = round_page(max); - - vm_size_t best_alloc = PAGE_SIZE; - vm_size_t alloc_size; - for (alloc_size = (2 * PAGE_SIZE); alloc_size <= ZONE_MAX_ALLOC_SIZE; alloc_size += PAGE_SIZE) { - if (ZONE_ALLOC_FRAG_PERCENT(alloc_size, size) < ZONE_ALLOC_FRAG_PERCENT(best_alloc, size)) { - best_alloc = alloc_size; - } - } - alloc = best_alloc; - if (max && (max < alloc)) - max = alloc; - - z->free_elements = NULL; - queue_init(&z->pages.any_free_foreign); - queue_init(&z->pages.all_free); - queue_init(&z->pages.intermediate); - queue_init(&z->pages.all_used); - z->cur_size = 0; - z->page_count = 0; - z->max_size = max; - z->elem_size = size; - z->alloc_size = alloc; - z->zone_name = name; - z->count = 0; - z->countfree = 0; - z->count_all_free_pages = 0; - z->sum_count = 0LL; - z->doing_alloc_without_vm_priv = FALSE; - z->doing_alloc_with_vm_priv = FALSE; - z->exhaustible = FALSE; - z->collectable = TRUE; - z->allows_foreign = FALSE; - z->expandable = TRUE; - z->waiting = FALSE; - z->async_pending = FALSE; - z->caller_acct = TRUE; - z->noencrypt = FALSE; - z->no_callout = FALSE; - z->async_prio_refill = FALSE; - z->gzalloc_exempt = FALSE; - z->alignment_required = FALSE; - z->zone_replenishing = FALSE; - z->prio_refill_watermark = 0; - z->zone_replenish_thread = NULL; - z->zp_count = 0; +#endif /* !ZALLOC_TEST */ +#pragma mark zone creation, configuration, destruction +#if !ZALLOC_TEST -#if CONFIG_ZLEAKS - z->zleak_capture = 0; - z->zleak_on = FALSE; -#endif /* CONFIG_ZLEAKS */ +static zone_t +zone_init_defaults(zone_id_t zid) +{ + zone_t z = &zone_array[zid]; - lock_zone_init(z); + z->z_wired_max = ~0u; + z->collectable = true; + z->expandable = true; + z->z_submap_idx = Z_SUBMAP_IDX_GENERAL; - /* - * Add the zone to the all-zones list. - */ - simple_lock(&all_zones_lock); - z->index = num_zones; - num_zones++; - simple_unlock(&all_zones_lock); + lck_spin_init(&z->z_lock, &zone_locks_grp, LCK_ATTR_NULL); + STAILQ_INIT(&z->z_recirc); + return z; +} - /* - * Check for and set up zone leak detection if requested via boot-args. We recognized two - * boot-args: - * - * zlog= - * zrecs= - * - * The zlog arg is used to specify the zone name that should be logged, and zrecs is used to - * control the size of the log. If zrecs is not specified, a default value is used. - */ +static bool +zone_is_initializing(zone_t z) +{ + return !z->z_self && !z->z_destroyed; +} + +void +zone_set_submap_idx(zone_t zone, unsigned int sub_map_idx) +{ + if (!zone_is_initializing(zone)) { + panic("%s: called after zone_create()", __func__); + } + if (sub_map_idx > zone_last_submap_idx) { + panic("zone_set_submap_idx(%d) > %d", sub_map_idx, zone_last_submap_idx); + } + zone->z_submap_idx = sub_map_idx; +} - if (num_zones_logged < max_num_zones_to_log) { +void +zone_set_noexpand(zone_t zone, vm_size_t nelems) +{ + if (!zone_is_initializing(zone)) { + panic("%s: called after zone_create()", __func__); + } + zone->expandable = false; + zone->z_wired_max = zone_alloc_pages_for_nelems(zone, nelems); +} - int i = 1; /* zlog0 isn't allowed. */ - boolean_t zone_logging_enabled = FALSE; - char zlog_name[MAX_ZONE_NAME] = ""; /* Temp. buffer to create the strings zlog1, zlog2 etc... */ +void +zone_set_exhaustible(zone_t zone, vm_size_t nelems) +{ + if (!zone_is_initializing(zone)) { + panic("%s: called after zone_create()", __func__); + } + zone->expandable = false; + zone->exhaustible = true; + zone->z_wired_max = zone_alloc_pages_for_nelems(zone, nelems); +} - while (i <= max_num_zones_to_log) { +/** + * @function zone_create_find + * + * @abstract + * Finds an unused zone for the given name and element size. + * + * @param name the zone name + * @param size the element size (including redzones, ...) + * @param flags the flags passed to @c zone_create* + * @param zid_inout the desired zone ID or ZONE_ID_ANY + * + * @returns a zone to initialize further. + */ +static zone_t +zone_create_find( + const char *name, + vm_size_t size, + zone_create_flags_t flags, + zone_id_t *zid_inout) +{ + zone_id_t nzones, zid = *zid_inout; + zone_t z; - snprintf(zlog_name, MAX_ZONE_NAME, "zlog%d", i); + simple_lock(&all_zones_lock, &zone_locks_grp); - if (PE_parse_boot_argn(zlog_name, zone_name_to_log, sizeof(zone_name_to_log)) == TRUE) { - if (log_this_zone(z->zone_name, zone_name_to_log)) { - z->zone_logging = TRUE; - zone_logging_enabled = TRUE; - num_zones_logged++; - break; - } - } - i++; + nzones = (zone_id_t)os_atomic_load(&num_zones, relaxed); + assert(num_zones_in_use <= nzones && nzones < MAX_ZONES); + + if (__improbable(nzones < ZONE_ID__FIRST_DYNAMIC)) { + /* + * The first time around, make sure the reserved zone IDs + * have an initialized lock as zone_index_foreach() will + * enumerate them. + */ + while (nzones < ZONE_ID__FIRST_DYNAMIC) { + zone_init_defaults(nzones++); } - if (zone_logging_enabled == FALSE) { - /* - * Backwards compat. with the old boot-arg used to specify single zone logging i.e. zlog - * Needs to happen after the newer zlogn checks because the prefix will match all the zlogn - * boot-args. - */ - if (PE_parse_boot_argn("zlog", zone_name_to_log, sizeof(zone_name_to_log)) == TRUE) { - if (log_this_zone(z->zone_name, zone_name_to_log)) { - z->zone_logging = TRUE; - zone_logging_enabled = TRUE; - num_zones_logged++; - } - } + os_atomic_store(&num_zones, nzones, release); + } + + if (zid != ZONE_ID_ANY) { + if (zid >= ZONE_ID__FIRST_DYNAMIC) { + panic("zone_create: invalid desired zone ID %d for %s", + zid, name); } + if (flags & ZC_DESTRUCTIBLE) { + panic("zone_create: ID %d (%s) must be permanent", zid, name); + } + if (zone_array[zid].z_self) { + panic("zone_create: creating zone ID %d (%s) twice", zid, name); + } + z = &zone_array[zid]; + } else { + if (flags & ZC_DESTRUCTIBLE) { + /* + * If possible, find a previously zdestroy'ed zone in the + * zone_array that we can reuse. + */ + for (int i = bitmap_first(zone_destroyed_bitmap, MAX_ZONES); + i >= 0; i = bitmap_next(zone_destroyed_bitmap, i)) { + z = &zone_array[i]; - if (log_records_init == FALSE && zone_logging_enabled == TRUE) { - if (PE_parse_boot_argn("zrecs", &log_records, sizeof(log_records)) == TRUE) { /* - * Don't allow more than ZRECORDS_MAX records even if the user asked for more. - * This prevents accidentally hogging too much kernel memory and making the system - * unusable. + * If the zone name and the element size are the + * same, we can just reuse the old zone struct. */ - - log_records = MIN(ZRECORDS_MAX, log_records); - log_records_init = TRUE; - } else { - log_records = ZRECORDS_DEFAULT; - log_records_init = TRUE; + if (strcmp(z->z_name, name) || zone_elem_size(z) != size) { + continue; + } + bitmap_clear(zone_destroyed_bitmap, i); + z->z_destroyed = false; + z->z_self = z; + zid = (zone_id_t)i; + goto out; } } + zid = nzones++; + z = zone_init_defaults(zid); + /* - * If we want to log a zone, see if we need to allocate buffer space for the log. Some vm related zones are - * zinit'ed before we can do a kmem_alloc, so we have to defer allocation in that case. kmem_alloc_ready is set to - * TRUE once enough of the VM system is up and running to allow a kmem_alloc to work. If we want to log one - * of the VM related zones that's set up early on, we will skip allocation of the log until zinit is called again - * later on some other zone. So note we may be allocating a buffer to log a zone other than the one being initialized - * right now. + * The release barrier pairs with the acquire in + * zone_index_foreach() and makes sure that enumeration loops + * always see an initialized zone lock. */ - if (kmem_alloc_ready) { - - zone_t curr_zone = NULL; - unsigned int max_zones = 0, zone_idx = 0; - - simple_lock(&all_zones_lock); - max_zones = num_zones; - simple_unlock(&all_zones_lock); - - for (zone_idx = 0; zone_idx < max_zones; zone_idx++) { + os_atomic_store(&num_zones, nzones, release); + } - curr_zone = &(zone_array[zone_idx]); +out: + num_zones_in_use++; + simple_unlock(&all_zones_lock); - /* - * We work with the zone unlocked here because we could end up needing the zone lock to - * enable logging for this zone e.g. need a VM object to allocate memory to enable logging for the - * VM objects zone. - * - * We don't expect these zones to be needed at this early a time in boot and so take this chance. - */ - if (curr_zone->zone_logging && curr_zone->zlog_btlog == NULL) { + *zid_inout = zid; + return z; +} - curr_zone->zlog_btlog = btlog_create(log_records, MAX_ZTRACE_DEPTH, (corruption_debug_flag == FALSE) /* caller_will_remove_entries_for_element? */); +__abortlike +static void +zone_create_panic(const char *name, const char *f1, const char *f2) +{ + panic("zone_create: creating zone %s: flag %s and %s are incompatible", + name, f1, f2); +} +#define zone_create_assert_not_both(name, flags, current_flag, forbidden_flag) \ + if ((flags) & forbidden_flag) { \ + zone_create_panic(name, #current_flag, #forbidden_flag); \ + } - if (curr_zone->zlog_btlog) { +/* + * Adjusts the size of the element based on minimum size, alignment + * and kasan redzones + */ +static vm_size_t +zone_elem_adjust_size( + const char *name __unused, + vm_size_t elem_size, + zone_create_flags_t flags __unused, + uint32_t *redzone __unused) +{ + vm_size_t size; + /* + * Adjust element size for minimum size and pointer alignment + */ + size = (elem_size + sizeof(vm_offset_t) - 1) & -sizeof(vm_offset_t); + if (size < ZONE_MIN_ELEM_SIZE) { + size = ZONE_MIN_ELEM_SIZE; + } - printf("zone: logging started for zone %s\n", curr_zone->zone_name); - } else { - printf("zone: couldn't allocate memory for zrecords, turning off zleak logging\n"); - curr_zone->zone_logging = FALSE; - } - } +#if KASAN_ZALLOC + /* + * Expand the zone allocation size to include the redzones. + * + * For page-multiple zones add a full guard page because they + * likely require alignment. + */ + uint32_t redzone_tmp; + if (flags & (ZC_KASAN_NOREDZONE | ZC_PERCPU)) { + redzone_tmp = 0; + } else if ((size & PAGE_MASK) == 0) { + if (size != PAGE_SIZE && (flags & ZC_ALIGNMENT_REQUIRED)) { + panic("zone_create: zone %s can't provide more than PAGE_SIZE" + "alignment", name); + } + redzone_tmp = PAGE_SIZE; + } else if (flags & ZC_ALIGNMENT_REQUIRED) { + redzone_tmp = 0; + } else { + redzone_tmp = KASAN_GUARD_SIZE; + } + size += redzone_tmp * 2; + if (redzone) { + *redzone = redzone_tmp; + } +#endif + return size; +} +/* + * Returns the allocation chunk size that has least framentation + */ +static vm_size_t +zone_get_min_alloc_granule( + vm_size_t elem_size, + zone_create_flags_t flags) +{ + vm_size_t alloc_granule = PAGE_SIZE; + if (flags & ZC_PERCPU) { + alloc_granule = PAGE_SIZE * zpercpu_count(); + if (PAGE_SIZE % elem_size > 256) { + panic("zone_create: per-cpu zone has too much fragmentation"); + } + } else if ((elem_size & PAGE_MASK) == 0) { + /* zero fragmentation by definition */ + alloc_granule = elem_size; + } else if (alloc_granule % elem_size == 0) { + /* zero fragmentation by definition */ + } else { + vm_size_t frag = (alloc_granule % elem_size) * 100 / alloc_granule; + vm_size_t alloc_tmp = PAGE_SIZE; + while ((alloc_tmp += PAGE_SIZE) <= ZONE_MAX_ALLOC_SIZE) { + vm_size_t frag_tmp = (alloc_tmp % elem_size) * 100 / alloc_tmp; + if (frag_tmp < frag) { + frag = frag_tmp; + alloc_granule = alloc_tmp; } } } - -#if CONFIG_GZALLOC - gzalloc_zone_init(z); -#endif - return(z); + return alloc_granule; } -unsigned zone_replenish_loops, zone_replenish_wakeups, zone_replenish_wakeups_initiated, zone_replenish_throttle_count; -static void zone_replenish_thread(zone_t); +vm_size_t +zone_get_foreign_alloc_size( + const char *name __unused, + vm_size_t elem_size, + zone_create_flags_t flags, + uint16_t min_pages) +{ + vm_size_t adjusted_size = zone_elem_adjust_size(name, elem_size, flags, + NULL); + vm_size_t alloc_granule = zone_get_min_alloc_granule(adjusted_size, + flags); + vm_size_t min_size = min_pages * PAGE_SIZE; + /* + * Round up min_size to a multiple of alloc_granule + */ + return ((min_size + alloc_granule - 1) / alloc_granule) + * alloc_granule; +} -/* High priority VM privileged thread used to asynchronously refill a designated - * zone, such as the reserved VM map entry zone. - */ -__attribute__((noreturn)) -static void -zone_replenish_thread(zone_t z) +zone_t +zone_create_ext( + const char *name, + vm_size_t size, + zone_create_flags_t flags, + zone_id_t zid, + void (^extra_setup)(zone_t)) { - vm_size_t free_size; - current_thread()->options |= TH_OPT_VMPRIV; + vm_size_t alloc; + uint32_t redzone; + zone_t z; - for (;;) { - lock_zone(z); - z->zone_replenishing = TRUE; - assert(z->prio_refill_watermark != 0); - while ((free_size = (z->cur_size - (z->count * z->elem_size))) < (z->prio_refill_watermark * z->elem_size)) { - assert(z->doing_alloc_without_vm_priv == FALSE); - assert(z->doing_alloc_with_vm_priv == FALSE); - assert(z->async_prio_refill == TRUE); - - unlock_zone(z); - int zflags = KMA_KOBJECT|KMA_NOPAGEWAIT; - vm_offset_t space, alloc_size; - kern_return_t kr; - - if (vm_pool_low()) - alloc_size = round_page(z->elem_size); - else - alloc_size = z->alloc_size; - - if (z->noencrypt) - zflags |= KMA_NOENCRYPT; - - kr = kernel_memory_allocate(zone_map, &space, alloc_size, 0, zflags, VM_KERN_MEMORY_ZONE); - - if (kr == KERN_SUCCESS) { - zcram(z, space, alloc_size); - } else if (kr == KERN_RESOURCE_SHORTAGE) { - VM_PAGE_WAIT(); - } else if (kr == KERN_NO_SPACE) { - kr = kernel_memory_allocate(kernel_map, &space, alloc_size, 0, zflags, VM_KERN_MEMORY_ZONE); - if (kr == KERN_SUCCESS) { - zcram(z, space, alloc_size); - } else { - assert_wait_timeout(&z->zone_replenish_thread, THREAD_UNINT, 1, 100 * NSEC_PER_USEC); - thread_block(THREAD_CONTINUE_NULL); - } - } + if (size > ZONE_MAX_ALLOC_SIZE) { + panic("zone_create: element size too large: %zd", (size_t)size); + } - lock_zone(z); - zone_replenish_loops++; - } + if (size < 2 * sizeof(vm_size_t)) { + /* Elements are too small for kasan. */ + flags |= ZC_KASAN_NOQUARANTINE | ZC_KASAN_NOREDZONE; + } + + size = zone_elem_adjust_size(name, size, flags, &redzone); + /* + * Allocate the zone slot, return early if we found an older match. + */ + z = zone_create_find(name, size, flags, &zid); + if (__improbable(z->z_self)) { + /* We found a zone to reuse */ + return z; + } - z->zone_replenishing = FALSE; - /* Signal any potential throttled consumers, terminating - * their timer-bounded waits. + /* + * Initialize the zone properly. + */ + + /* + * If the kernel is post lockdown, copy the zone name passed in. + * Else simply maintain a pointer to the name string as it can only + * be a core XNU zone (no unloadable kext exists before lockdown). + */ + if (startup_phase >= STARTUP_SUB_LOCKDOWN) { + size_t nsz = MIN(strlen(name) + 1, MACH_ZONE_NAME_MAX_LEN); + char *buf = zalloc_permanent(nsz, ZALIGN_NONE); + strlcpy(buf, name, nsz); + z->z_name = buf; + } else { + z->z_name = name; + } + if (__probable(zone_array[ZONE_ID_PERCPU_PERMANENT].z_self)) { + z->z_stats = zalloc_percpu_permanent_type(struct zone_stats); + } else { + /* + * zone_init() hasn't run yet, use the storage provided by + * zone_stats_startup(), and zone_init() will replace it + * with the final value once the PERCPU zone exists. */ - thread_wakeup(z); + z->z_stats = __zpcpu_mangle_for_boot(&zone_stats_startup[zone_index(z)]); + } - assert_wait(&z->zone_replenish_thread, THREAD_UNINT); - unlock_zone(z); - thread_block(THREAD_CONTINUE_NULL); - zone_replenish_wakeups++; + alloc = zone_get_min_alloc_granule(size, flags); + + if (flags & ZC_KALLOC_HEAP) { + size_t rem = (alloc % size) / (alloc / size); + + /* + * Try to grow the elements size and spread them more if the remaining + * space is large enough. + */ + size += rem & ~(KALLOC_MINALIGN - 1); } -} -void -zone_prio_refill_configure(zone_t z, vm_size_t low_water_mark) { - z->prio_refill_watermark = low_water_mark; + z->z_elem_size = (uint16_t)size; + z->z_chunk_pages = (uint16_t)atop(alloc); + if (flags & ZC_PERCPU) { + z->z_chunk_elems = (uint16_t)(PAGE_SIZE / z->z_elem_size); + } else { + z->z_chunk_elems = (uint16_t)(alloc / z->z_elem_size); + } + if (zone_element_idx(zone_element_encode(0, + z->z_chunk_elems - 1, ZPM_AUTO)) != z->z_chunk_elems - 1) { + panic("zone_element_encode doesn't work for zone [%s]", name); + } - z->async_prio_refill = TRUE; - OSMemoryBarrier(); - kern_return_t tres = kernel_thread_start_priority((thread_continue_t)zone_replenish_thread, z, MAXPRI_KERNEL, &z->zone_replenish_thread); +#if KASAN_ZALLOC + z->z_kasan_redzone = redzone; + if (strncmp(name, "fakestack.", sizeof("fakestack.") - 1) == 0) { + z->kasan_fakestacks = true; + } +#endif - if (tres != KERN_SUCCESS) { - panic("zone_prio_refill_configure, thread create: 0x%x", tres); + /* + * Handle KPI flags + */ +#if __LP64__ + if (flags & ZC_SEQUESTER) { + z->z_va_sequester = true; + } +#endif + /* ZC_CACHING applied after all configuration is done */ + if (flags & ZC_NOCACHING) { + z->z_nocaching = true; } - thread_deallocate(z->zone_replenish_thread); -} + if (flags & ZC_PERCPU) { + /* + * ZC_ZFREE_CLEARMEM is forced because per-cpu zones allow for + * pointer-sized allocations which poisoning doesn't support. + */ + zone_create_assert_not_both(name, flags, ZC_PERCPU, ZC_ALLOW_FOREIGN); + z->z_percpu = true; + z->gzalloc_exempt = true; + z->z_free_zeroes = true; + } + if (flags & ZC_ZFREE_CLEARMEM) { + z->z_free_zeroes = true; + } + if (flags & ZC_NOGC) { + z->collectable = false; + } + if (flags & ZC_NOENCRYPT) { + z->z_noencrypt = true; + } + if (flags & ZC_ALIGNMENT_REQUIRED) { + z->alignment_required = true; + } + if (flags & ZC_NOGZALLOC) { + z->gzalloc_exempt = true; + } + if (flags & ZC_NOCALLOUT) { + z->no_callout = true; + } + if (flags & ZC_DESTRUCTIBLE) { + zone_create_assert_not_both(name, flags, ZC_DESTRUCTIBLE, ZC_ALLOW_FOREIGN); + z->z_destructible = true; + } -/* Initialize the metadata for an allocation chunk */ -static inline void -zcram_metadata_init(vm_offset_t newmem, vm_size_t size, struct zone_page_metadata *chunk_metadata) -{ - struct zone_page_metadata *page_metadata; + /* + * Handle Internal flags + */ + if (flags & ZC_ALLOW_FOREIGN) { + z->z_allows_foreign = true; + } + if ((ZSECURITY_OPTIONS_SUBMAP_USER_DATA & zsecurity_options) && + (flags & ZC_DATA_BUFFERS)) { + z->z_submap_idx = Z_SUBMAP_IDX_BAG_OF_BYTES; + } + if (flags & ZC_KASAN_NOQUARANTINE) { + z->kasan_noquarantine = true; + } + /* ZC_KASAN_NOREDZONE already handled */ - /* The first page is the real metadata for this allocation chunk. We mark the others as fake metadata */ - size -= PAGE_SIZE; - newmem += PAGE_SIZE; + /* + * Then if there's extra tuning, do it + */ + if (extra_setup) { + extra_setup(z); + } - for (; size > 0; newmem += PAGE_SIZE, size -= PAGE_SIZE) { - page_metadata = get_zone_page_metadata((struct zone_free_element *)newmem, TRUE); - assert(page_metadata != chunk_metadata); - PAGE_METADATA_SET_ZINDEX(page_metadata, MULTIPAGE_METADATA_MAGIC); - page_metadata_set_realmeta(page_metadata, chunk_metadata); - page_metadata->free_count = 0; + /* + * Configure debugging features + */ +#if CONFIG_GZALLOC + gzalloc_zone_init(z); /* might set z->gzalloc_tracked */ + if (z->gzalloc_tracked) { + z->z_nocaching = true; } - return; -} +#endif +#if ZONE_ENABLE_LOGGING + if (!z->gzalloc_tracked && num_zones_logged < max_num_zones_to_log) { + /* + * Check for and set up zone leak detection if requested via boot-args. + * might set z->zone_logging + */ + zone_setup_logging(z); + } +#endif /* ZONE_ENABLE_LOGGING */ +#if VM_MAX_TAG_ZONES + if (!z->gzalloc_tracked && z->kalloc_heap && zone_tagging_on) { + static int tag_zone_index; + vm_offset_t esize = zone_elem_size(z); + z->tags = true; + z->tags_inline = (((page_size + esize - 1) / esize) <= + (sizeof(uint32_t) / sizeof(uint16_t))); + z->tag_zone_index = os_atomic_inc_orig(&tag_zone_index, relaxed); + assert(z->tag_zone_index < VM_MAX_TAG_ZONES); + } +#endif + /* + * Finally, fixup properties based on security policies, boot-args, ... + */ + if ((ZSECURITY_OPTIONS_SUBMAP_USER_DATA & zsecurity_options) && + z->kalloc_heap == KHEAP_ID_DATA_BUFFERS) { + z->z_submap_idx = Z_SUBMAP_IDX_BAG_OF_BYTES; + } +#if __LP64__ + if ((ZSECURITY_OPTIONS_SEQUESTER & zsecurity_options) && + (flags & ZC_NOSEQUESTER) == 0 && + z->z_submap_idx == Z_SUBMAP_IDX_GENERAL) { + z->z_va_sequester = true; + } +#endif + /* + * Clear entire element for non data zones and upto zp_min_size for + * data zones. + */ + if (z->z_submap_idx != Z_SUBMAP_IDX_BAG_OF_BYTES) { + z->z_free_zeroes = true; + } else if (size <= zp_min_size) { + z->z_free_zeroes = true; + } -/* - * Boolean Random Number Generator for generating booleans to randomize - * the order of elements in newly zcram()'ed memory. The algorithm is a - * modified version of the KISS RNG proposed in the paper: - * http://stat.fsu.edu/techreports/M802.pdf - * The modifications have been documented in the technical paper - * paper from UCL: - * http://www0.cs.ucl.ac.uk/staff/d.jones/GoodPracticeRNG.pdf - */ - -static void random_bool_gen_entropy( - int *buffer, - int count) -{ - - int i, t; - simple_lock(&bool_gen_lock); - for (i = 0; i < count; i++) { - bool_gen_seed[1] ^= (bool_gen_seed[1] << 5); - bool_gen_seed[1] ^= (bool_gen_seed[1] >> 7); - bool_gen_seed[1] ^= (bool_gen_seed[1] << 22); - t = bool_gen_seed[2] + bool_gen_seed[3] + bool_gen_global; - bool_gen_seed[2] = bool_gen_seed[3]; - bool_gen_global = t < 0; - bool_gen_seed[3] = t &2147483647; - bool_gen_seed[0] += 1411392427; - buffer[i] = (bool_gen_seed[0] + bool_gen_seed[1] + bool_gen_seed[3]); - } - simple_unlock(&bool_gen_lock); -} - -static boolean_t random_bool_gen( - int *buffer, - int index, - int bufsize) -{ - int valindex, bitpos; - valindex = (index / (8 * sizeof(int))) % bufsize; - bitpos = index % (8 * sizeof(int)); - return (boolean_t)(buffer[valindex] & (1 << bitpos)); -} - -static void -random_free_to_zone( - zone_t zone, - vm_offset_t newmem, - vm_offset_t first_element_offset, - int element_count, - int *entropy_buffer) -{ - vm_offset_t last_element_offset; - vm_offset_t element_addr; - vm_size_t elem_size; - int index; - - elem_size = zone->elem_size; - last_element_offset = first_element_offset + ((element_count * elem_size) - elem_size); - for (index = 0; index < element_count; index++) { - assert(first_element_offset <= last_element_offset); - if ( -#if DEBUG || DEVELOPMENT - leak_scan_debug_flag || -#endif /* DEBUG || DEVELOPMENT */ - random_bool_gen(entropy_buffer, index, MAX_ENTROPY_PER_ZCRAM)) { - element_addr = newmem + first_element_offset; - first_element_offset += elem_size; + if ((flags & ZC_CACHING) && !z->z_nocaching) { + /* + * If zcache hasn't been initialized yet, remember our decision, + * + * zone_enable_caching() will be called again by + * zcache_bootstrap(), while the system is still single + * threaded, to build the missing caches. + */ + if (__probable(zc_magazine_zone)) { + zone_enable_caching(z); } else { - element_addr = newmem + last_element_offset; - last_element_offset -= elem_size; + z->z_pcpu_cache = + __zpcpu_mangle_for_boot(&zone_cache_startup[zid]); } - if (element_addr != (vm_offset_t)zone) { - zone->count++; /* compensate for free_to_zone */ - free_to_zone(zone, element_addr, FALSE); + } + + if (zp_factor != 0 && !z->z_free_zeroes) { + if (__probable(zone_array[ZONE_ID_PERCPU_PERMANENT].z_self)) { + zpercpu_foreach(zs, z->z_stats) { + zs->zs_poison_seqno = zone_poison_count_init(z); + } + } else { + zone_stats_startup[zid].zs_poison_seqno = + zone_poison_count_init(z); } - zone->cur_size += elem_size; } + + zone_lock(z); + z->z_self = z; + zone_unlock(z); + + return z; +} + +__startup_func +void +zone_create_startup(struct zone_create_startup_spec *spec) +{ + *spec->z_var = zone_create_ext(spec->z_name, spec->z_size, + spec->z_flags, spec->z_zid, spec->z_setup); } /* - * Cram the given memory into the specified zone. Update the zone page count accordingly. + * The 4 first field of a zone_view and a zone alias, so that the zone_or_view_t + * union works. trust but verify. */ +#define zalloc_check_zov_alias(f1, f2) \ + static_assert(offsetof(struct zone, f1) == offsetof(struct zone_view, f2)) +zalloc_check_zov_alias(z_self, zv_zone); +zalloc_check_zov_alias(z_stats, zv_stats); +zalloc_check_zov_alias(z_name, zv_name); +zalloc_check_zov_alias(z_views, zv_next); +#undef zalloc_check_zov_alias + +__startup_func void -zcram( - zone_t zone, - vm_offset_t newmem, - vm_size_t size) +zone_view_startup_init(struct zone_view_startup_spec *spec) { - vm_size_t elem_size; - boolean_t from_zm = FALSE; - int element_count; - int entropy_buffer[MAX_ENTROPY_PER_ZCRAM]; - - /* Basic sanity checks */ - assert(zone != ZONE_NULL && newmem != (vm_offset_t)0); - assert(!zone->collectable || zone->allows_foreign - || (from_zone_map(newmem, size))); - - elem_size = zone->elem_size; - - KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_ZALLOC, ZALLOC_ZCRAM) | DBG_FUNC_START, VM_KERNEL_ADDRPERM(zone), size, 0, 0, 0); - - if (from_zone_map(newmem, size)) - from_zm = TRUE; - - if (!from_zm) { - /* We cannot support elements larger than page size for foreign memory because we - * put metadata on the page itself for each page of foreign memory. We need to do - * this in order to be able to reach the metadata when any element is freed - */ - assert((zone->allows_foreign == TRUE) && (zone->elem_size <= (PAGE_SIZE - sizeof(struct zone_page_metadata)))); - } - - if (zalloc_debug & ZALLOC_DEBUG_ZCRAM) - kprintf("zcram(%p[%s], 0x%lx%s, 0x%lx)\n", zone, zone->zone_name, - (unsigned long)newmem, from_zm ? "" : "[F]", (unsigned long)size); - - ZONE_PAGE_COUNT_INCR(zone, (size / PAGE_SIZE)); - - random_bool_gen_entropy(entropy_buffer, MAX_ENTROPY_PER_ZCRAM); - - /* - * Initialize the metadata for all pages. We dont need the zone lock - * here because we are not manipulating any zone related state yet. - */ - - struct zone_page_metadata *chunk_metadata; - size_t zone_page_metadata_size = sizeof(struct zone_page_metadata); - - assert((newmem & PAGE_MASK) == 0); - assert((size & PAGE_MASK) == 0); - - chunk_metadata = get_zone_page_metadata((struct zone_free_element *)newmem, TRUE); - chunk_metadata->pages.next = NULL; - chunk_metadata->pages.prev = NULL; - page_metadata_set_freelist(chunk_metadata, 0); - PAGE_METADATA_SET_ZINDEX(chunk_metadata, zone->index); - chunk_metadata->free_count = 0; - chunk_metadata->page_count = (size / PAGE_SIZE); + struct kalloc_heap *heap = NULL; + zone_view_t zv = spec->zv_view; + zone_t z; - zcram_metadata_init(newmem, size, chunk_metadata); + switch (spec->zv_heapid) { + case KHEAP_ID_DEFAULT: + heap = KHEAP_DEFAULT; + break; + case KHEAP_ID_DATA_BUFFERS: + heap = KHEAP_DATA_BUFFERS; + break; + case KHEAP_ID_KEXT: + heap = KHEAP_KEXT; + break; + default: + heap = NULL; + } - lock_zone(zone); - enqueue_tail(&zone->pages.all_used, &(chunk_metadata->pages)); + if (heap) { + z = kalloc_heap_zone_for_size(heap, spec->zv_size); + assert(z); + } else { + z = spec->zv_zone; + assert(spec->zv_size <= zone_elem_size(z)); + } - if (!from_zm) { - /* We cannot support elements larger than page size for foreign memory because we - * put metadata on the page itself for each page of foreign memory. We need to do - * this in order to be able to reach the metadata when any element is freed + zv->zv_zone = z; + zv->zv_stats = zalloc_percpu_permanent_type(struct zone_stats); + zv->zv_next = z->z_views; + if (z->z_views == NULL && z->kalloc_heap == KHEAP_ID_NONE) { + /* + * count the raw view for zones not in a heap, + * kalloc_heap_init() already counts it for its members. */ - - for (; size > 0; newmem += PAGE_SIZE, size -= PAGE_SIZE) { - vm_offset_t first_element_offset = 0; - if (zone_page_metadata_size % ZONE_ELEMENT_ALIGNMENT == 0){ - first_element_offset = zone_page_metadata_size; - } else { - first_element_offset = zone_page_metadata_size + (ZONE_ELEMENT_ALIGNMENT - (zone_page_metadata_size % ZONE_ELEMENT_ALIGNMENT)); - } - element_count = (int)((PAGE_SIZE - first_element_offset) / elem_size); - random_free_to_zone(zone, newmem, first_element_offset, element_count, entropy_buffer); - } + zone_view_count += 2; } else { - element_count = (int)(size / elem_size); - random_free_to_zone(zone, newmem, 0, element_count, entropy_buffer); + zone_view_count += 1; } - unlock_zone(zone); - - KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_ZALLOC, ZALLOC_ZCRAM) | DBG_FUNC_END, VM_KERNEL_ADDRPERM(zone), 0, 0, 0, 0); - + z->z_views = zv; } -/* - * Fill a zone with enough memory to contain at least nelem elements. - * Memory is obtained with kmem_alloc_kobject from the kernel_map. - * Return the number of elements actually put into the zone, which may - * be more than the caller asked for since the memory allocation is - * rounded up to a full page. - */ -int -zfill( - zone_t zone, - int nelem) +zone_t +zone_create( + const char *name, + vm_size_t size, + zone_create_flags_t flags) { - kern_return_t kr; - vm_size_t size; - vm_offset_t memory; - int nalloc; - - assert(nelem > 0); - if (nelem <= 0) - return 0; - size = nelem * zone->elem_size; - size = round_page(size); - kr = kmem_alloc_kobject(kernel_map, &memory, size, VM_KERN_MEMORY_ZONE); - if (kr != KERN_SUCCESS) - return 0; - - zone_change(zone, Z_FOREIGN, TRUE); - zcram(zone, memory, size); - nalloc = (int)(size / zone->elem_size); - assert(nalloc >= nelem); + return zone_create_ext(name, size, flags, ZONE_ID_ANY, NULL); +} - return nalloc; +zone_t +zinit( + vm_size_t size, /* the size of an element */ + vm_size_t max, /* maximum memory to use */ + vm_size_t alloc __unused, /* allocation size */ + const char *name) /* a name for the zone */ +{ + zone_t z = zone_create(name, size, ZC_DESTRUCTIBLE); + z->z_wired_max = zone_alloc_pages_for_nelems(z, max / size); + return z; } -/* - * Initialize the "zone of zones" which uses fixed memory allocated - * earlier in memory initialization. zone_bootstrap is called - * before zone_init. - */ void -zone_bootstrap(void) +zdestroy(zone_t z) { - char temp_buf[16]; - unsigned int i; + unsigned int zindex = zone_index(z); - if (!PE_parse_boot_argn("zalloc_debug", &zalloc_debug, sizeof(zalloc_debug))) - zalloc_debug = 0; + current_thread()->options |= TH_OPT_ZONE_PRIV; + lck_mtx_lock(&zone_gc_lock); - /* Set up zone element poisoning */ - zp_init(); + zone_reclaim(z, ZONE_RECLAIM_DESTROY); + + lck_mtx_unlock(&zone_gc_lock); + current_thread()->options &= ~TH_OPT_ZONE_PRIV; - /* Seed the random boolean generator for elements in zone free list */ - for (i = 0; i < RANDOM_BOOL_GEN_SEED_COUNT; i++) { - bool_gen_seed[i] = (unsigned int)early_random(); +#if CONFIG_GZALLOC + if (__improbable(z->gzalloc_tracked)) { + /* If the zone is gzalloc managed dump all the elements in the free cache */ + gzalloc_empty_free_cache(z); } - simple_lock_init(&bool_gen_lock, 0); +#endif - /* should zlog log to debug zone corruption instead of leaks? */ - if (PE_parse_boot_argn("-zc", temp_buf, sizeof(temp_buf))) { - corruption_debug_flag = TRUE; - } + zone_lock(z); -#if DEBUG || DEVELOPMENT - /* disable element location randomization in a page */ - if (PE_parse_boot_argn("-zl", temp_buf, sizeof(temp_buf))) { - leak_scan_debug_flag = TRUE; + while (!zone_pva_is_null(z->z_pageq_va)) { + struct zone_page_metadata *meta; + vm_offset_t free_addr; + + zone_counter_sub(z, z_va_cur, z->z_percpu ? 1 : z->z_chunk_pages); + meta = zone_meta_queue_pop_native(z, &z->z_pageq_va, &free_addr); + assert(meta->zm_chunk_len <= ZM_CHUNK_LEN_MAX); + bzero(meta, sizeof(*meta) * z->z_chunk_pages); + zone_unlock(z); + kmem_free(zone_submap(z), free_addr, ptoa(z->z_chunk_pages)); + zone_lock(z); } + +#if !KASAN_ZALLOC + /* Assert that all counts are zero */ + if (z->z_elems_avail || z->z_elems_free || + zone_size_wired(z) || z->z_va_cur) { + panic("zdestroy: Zone %s%s isn't empty at zdestroy() time", + zone_heap_name(z), z->z_name); + } + + /* consistency check: make sure everything is indeed empty */ + assert(zone_pva_is_null(z->z_pageq_empty)); + assert(zone_pva_is_null(z->z_pageq_partial)); + assert(zone_pva_is_null(z->z_pageq_full)); + assert(zone_pva_is_null(z->z_pageq_va)); #endif - simple_lock_init(&all_zones_lock, 0); + zone_unlock(z); - num_zones = 0; - thread_call_setup(&call_async_alloc, zalloc_async, NULL); + simple_lock(&all_zones_lock, &zone_locks_grp); - /* initializing global lock group for zones */ - lck_grp_attr_setdefault(&zone_locks_grp_attr); - lck_grp_init(&zone_locks_grp, "zone_locks", &zone_locks_grp_attr); + assert(!bitmap_test(zone_destroyed_bitmap, zindex)); + /* Mark the zone as empty in the bitmap */ + bitmap_set(zone_destroyed_bitmap, zindex); + num_zones_in_use--; + assert(num_zones_in_use > 0); - lck_attr_setdefault(&zone_metadata_lock_attr); - lck_mtx_init_ext(&zone_metadata_region_lck, &zone_metadata_region_lck_ext, &zone_locks_grp, &zone_metadata_lock_attr); + simple_unlock(&all_zones_lock); } -/* Global initialization of Zone Allocator. - * Runs after zone_bootstrap. +#endif /* !ZALLOC_TEST */ +#pragma mark zalloc module init +#if !ZALLOC_TEST + +/* + * Initialize the "zone of zones" which uses fixed memory allocated + * earlier in memory initialization. zone_bootstrap is called + * before zone_init. */ +__startup_func void -zone_init( - vm_size_t max_zonemap_size) +zone_bootstrap(void) { - kern_return_t retval; - vm_offset_t zone_min; - vm_offset_t zone_max; - vm_offset_t zone_metadata_space; - unsigned int zone_pages; - - retval = kmem_suballoc(kernel_map, &zone_min, max_zonemap_size, - FALSE, VM_FLAGS_ANYWHERE | VM_FLAGS_PERMANENT | VM_MAKE_TAG(VM_KERN_MEMORY_ZONE), - &zone_map); + /* Validate struct zone_packed_virtual_address expectations */ + static_assert((intptr_t)VM_MIN_KERNEL_ADDRESS < 0, "the top bit must be 1"); + if (VM_KERNEL_POINTER_SIGNIFICANT_BITS - PAGE_SHIFT > 31) { + panic("zone_pva_t can't pack a kernel page address in 31 bits"); + } - if (retval != KERN_SUCCESS) - panic("zone_init: kmem_suballoc failed"); - zone_max = zone_min + round_page(max_zonemap_size); -#if CONFIG_GZALLOC - gzalloc_init(max_zonemap_size); -#endif - /* - * Setup garbage collection information: - */ - zone_map_min_address = zone_min; - zone_map_max_address = zone_max; + zpercpu_early_count = ml_early_cpu_max_number() + 1; - zone_pages = (unsigned int)atop_kernel(zone_max - zone_min); - zone_metadata_space = round_page(zone_pages * sizeof(struct zone_page_metadata)); - retval = kernel_memory_allocate(zone_map, &zone_metadata_region_min, zone_metadata_space, - 0, KMA_KOBJECT | KMA_VAONLY | KMA_PERMANENT, VM_KERN_MEMORY_OSFMK); - if (retval != KERN_SUCCESS) - panic("zone_init: zone_metadata_region initialization failed!"); - zone_metadata_region_max = zone_metadata_region_min + zone_metadata_space; + /* Set up zone element poisoning */ + zp_bootstrap(); -#if defined(__LP64__) /* - * ensure that any vm_page_t that gets created from - * the vm_page zone can be packed properly (see vm_page.h - * for the packing requirements + * the KASAN quarantine for kalloc doesn't understand heaps + * and trips the heap confusion panics. At the end of the day, + * all these security measures are double duty with KASAN. + * + * On 32bit kernels, these protections are just too expensive. */ - if ((vm_page_t)(VM_PAGE_UNPACK_PTR(VM_PAGE_PACK_PTR(zone_metadata_region_max))) != (vm_page_t)zone_metadata_region_max) - panic("VM_PAGE_PACK_PTR failed on zone_metadata_region_max - %p", (void *)zone_metadata_region_max); - - if ((vm_page_t)(VM_PAGE_UNPACK_PTR(VM_PAGE_PACK_PTR(zone_map_max_address))) != (vm_page_t)zone_map_max_address) - panic("VM_PAGE_PACK_PTR failed on zone_map_max_address - %p", (void *)zone_map_max_address); +#if !defined(__LP64__) || KASAN_ZALLOC + zsecurity_options &= ~ZSECURITY_OPTIONS_SEQUESTER; + zsecurity_options &= ~ZSECURITY_OPTIONS_SUBMAP_USER_DATA; + zsecurity_options &= ~ZSECURITY_OPTIONS_SEQUESTER_KEXT_KALLOC; #endif - lck_grp_attr_setdefault(&zone_gc_lck_grp_attr); - lck_grp_init(&zone_gc_lck_grp, "zone_gc", &zone_gc_lck_grp_attr); - lck_attr_setdefault(&zone_gc_lck_attr); - lck_mtx_init_ext(&zone_gc_lock, &zone_gc_lck_ext, &zone_gc_lck_grp, &zone_gc_lck_attr); - -#if CONFIG_ZLEAKS - /* - * Initialize the zone leak monitor - */ - zleak_init(max_zonemap_size); -#endif /* CONFIG_ZLEAKS */ -} - -extern volatile SInt32 kfree_nop_count; + thread_call_setup_with_options(&zone_expand_callout, + zone_expand_async, NULL, THREAD_CALL_PRIORITY_HIGH, + THREAD_CALL_OPTIONS_ONCE); -#pragma mark - -#pragma mark zalloc_canblock + thread_call_setup_with_options(&zone_defrag_callout, + zone_defrag_async, NULL, THREAD_CALL_PRIORITY_USER, + THREAD_CALL_OPTIONS_ONCE); +} -/* - * zalloc returns an element from the specified zone. - */ -static void * -zalloc_internal( - zone_t zone, - boolean_t canblock, - boolean_t nopagewait) -{ - vm_offset_t addr = 0; - kern_return_t retval; - uintptr_t zbt[MAX_ZTRACE_DEPTH]; /* used in zone leak logging and zone leak detection */ - int numsaved = 0; - boolean_t zone_replenish_wakeup = FALSE, zone_alloc_throttle = FALSE; -#if CONFIG_GZALLOC - boolean_t did_gzalloc = FALSE; +#if __LP64__ +#if ARM_LARGE_MEMORY || __x86_64__ +#define ZONE_MAP_VIRTUAL_SIZE_LP64 (128ULL * 1024ULL * 1024 * 1024) +#else +#define ZONE_MAP_VIRTUAL_SIZE_LP64 (32ULL * 1024ULL * 1024 * 1024) #endif - thread_t thr = current_thread(); - boolean_t check_poison = FALSE; - boolean_t set_doing_alloc_with_vm_priv = FALSE; +#endif /* __LP64__ */ -#if CONFIG_ZLEAKS - uint32_t zleak_tracedepth = 0; /* log this allocation if nonzero */ -#endif /* CONFIG_ZLEAKS */ +#define ZONE_GUARD_SIZE (64UL << 10) - assert(zone != ZONE_NULL); +#if __LP64__ +static inline vm_offset_t +zone_restricted_va_max(void) +{ + vm_offset_t compressor_max = VM_PACKING_MAX_PACKABLE(C_SLOT_PACKED_PTR); + vm_offset_t vm_page_max = VM_PACKING_MAX_PACKABLE(VM_PAGE_PACKED_PTR); -#if CONFIG_GZALLOC - addr = gzalloc_alloc(zone, canblock); - did_gzalloc = (addr != 0); + return trunc_page(MIN(compressor_max, vm_page_max)); +} #endif - /* - * If zone logging is turned on and this is the zone we're tracking, grab a backtrace. - */ - if (__improbable(DO_LOGGING(zone))) - numsaved = OSBacktrace((void*) zbt, MAX_ZTRACE_DEPTH); - -#if CONFIG_ZLEAKS - /* - * Zone leak detection: capture a backtrace every zleak_sample_factor - * allocations in this zone. - */ - if (__improbable(zone->zleak_on && sample_counter(&zone->zleak_capture, zleak_sample_factor) == TRUE)) { - /* Avoid backtracing twice if zone logging is on */ - if (numsaved == 0) - zleak_tracedepth = backtrace(zbt, MAX_ZTRACE_DEPTH); - else - zleak_tracedepth = numsaved; +__startup_func +static void +zone_tunables_fixup(void) +{ + if (zone_map_jetsam_limit == 0 || zone_map_jetsam_limit > 100) { + zone_map_jetsam_limit = ZONE_MAP_JETSAM_LIMIT_DEFAULT; } -#endif /* CONFIG_ZLEAKS */ - - lock_zone(zone); - - if (zone->async_prio_refill && zone->zone_replenish_thread) { - do { - vm_size_t zfreec = (zone->cur_size - (zone->count * zone->elem_size)); - vm_size_t zrefillwm = zone->prio_refill_watermark * zone->elem_size; - zone_replenish_wakeup = (zfreec < zrefillwm); - zone_alloc_throttle = (zfreec < (zrefillwm / 2)) && ((thr->options & TH_OPT_VMPRIV) == 0); - - if (zone_replenish_wakeup) { - zone_replenish_wakeups_initiated++; - /* Signal the potentially waiting - * refill thread. - */ - thread_wakeup(&zone->zone_replenish_thread); - unlock_zone(zone); - /* Scheduling latencies etc. may prevent - * the refill thread from keeping up - * with demand. Throttle consumers - * when we fall below half the - * watermark, unless VM privileged - */ - if (zone_alloc_throttle) { - zone_replenish_throttle_count++; - assert_wait_timeout(zone, THREAD_UNINT, 1, NSEC_PER_MSEC); - thread_block(THREAD_CONTINUE_NULL); - } - lock_zone(zone); - } - } while (zone_alloc_throttle == TRUE); - } - - if (__probable(addr == 0)) - addr = try_alloc_from_zone(zone, &check_poison); - - - while ((addr == 0) && canblock) { - /* - * zone is empty, try to expand it - * - * Note that we now allow up to 2 threads (1 vm_privliged and 1 non-vm_privliged) - * to expand the zone concurrently... this is necessary to avoid stalling - * vm_privileged threads running critical code necessary to continue compressing/swapping - * pages (i.e. making new free pages) from stalling behind non-vm_privileged threads - * waiting to acquire free pages when the vm_page_free_count is below the - * vm_page_free_reserved limit. - */ - if ((zone->doing_alloc_without_vm_priv || zone->doing_alloc_with_vm_priv) && - (((thr->options & TH_OPT_VMPRIV) == 0) || zone->doing_alloc_with_vm_priv)) { - /* - * This is a non-vm_privileged thread and a non-vm_privileged or - * a vm_privileged thread is already expanding the zone... - * OR - * this is a vm_privileged thread and a vm_privileged thread is - * already expanding the zone... - * - * In either case wait for a thread to finish, then try again. - */ - zone->waiting = TRUE; - zone_sleep(zone); - } else { - vm_offset_t space; - vm_size_t alloc_size; - int retry = 0; - - if ((zone->cur_size + zone->elem_size) > - zone->max_size) { - if (zone->exhaustible) - break; - if (zone->expandable) { - /* - * We're willing to overflow certain - * zones, but not without complaining. - * - * This is best used in conjunction - * with the collectable flag. What we - * want is an assurance we can get the - * memory back, assuming there's no - * leak. - */ - zone->max_size += (zone->max_size >> 1); - } else { - unlock_zone(zone); - - panic_include_zprint = TRUE; -#if CONFIG_ZLEAKS - if (zleak_state & ZLEAK_STATE_ACTIVE) - panic_include_ztrace = TRUE; -#endif /* CONFIG_ZLEAKS */ - panic("zalloc: zone \"%s\" empty.", zone->zone_name); - } - } - /* - * It is possible that a BG thread is refilling/expanding the zone - * and gets pre-empted during that operation. That blocks all other - * threads from making progress leading to a watchdog timeout. To - * avoid that, boost the thread priority using the rwlock boost - */ - set_thread_rwlock_boost(); - - if ((thr->options & TH_OPT_VMPRIV)) { - zone->doing_alloc_with_vm_priv = TRUE; - set_doing_alloc_with_vm_priv = TRUE; - } else { - zone->doing_alloc_without_vm_priv = TRUE; - } - unlock_zone(zone); - - for (;;) { - int zflags = KMA_KOBJECT|KMA_NOPAGEWAIT; - - if (vm_pool_low() || retry >= 1) - alloc_size = - round_page(zone->elem_size); - else - alloc_size = zone->alloc_size; - - if (zone->noencrypt) - zflags |= KMA_NOENCRYPT; - - retval = kernel_memory_allocate(zone_map, &space, alloc_size, 0, zflags, VM_KERN_MEMORY_ZONE); - if (retval == KERN_SUCCESS) { -#if CONFIG_ZLEAKS - if ((zleak_state & (ZLEAK_STATE_ENABLED | ZLEAK_STATE_ACTIVE)) == ZLEAK_STATE_ENABLED) { - if (zone_map->size >= zleak_global_tracking_threshold) { - kern_return_t kr; - - kr = zleak_activate(); - if (kr != KERN_SUCCESS) { - printf("Failed to activate live zone leak debugging (%d).\n", kr); - } - } - } - - if ((zleak_state & ZLEAK_STATE_ACTIVE) && !(zone->zleak_on)) { - if (zone->cur_size > zleak_per_zone_tracking_threshold) { - zone->zleak_on = TRUE; - } - } -#endif /* CONFIG_ZLEAKS */ - zcram(zone, space, alloc_size); - - break; - } else if (retval != KERN_RESOURCE_SHORTAGE) { - retry++; - - if (retry == 2) { - zone_gc(); - printf("zalloc did gc\n"); - zone_display_zprint(); - } - if (retry == 3) { - panic_include_zprint = TRUE; -#if CONFIG_ZLEAKS - if ((zleak_state & ZLEAK_STATE_ACTIVE)) { - panic_include_ztrace = TRUE; - } -#endif /* CONFIG_ZLEAKS */ - if (retval == KERN_NO_SPACE) { - zone_t zone_largest = zone_find_largest(); - panic("zalloc: zone map exhausted while allocating from zone %s, likely due to memory leak in zone %s (%lu total bytes, %d elements allocated)", - zone->zone_name, zone_largest->zone_name, - (unsigned long)zone_largest->cur_size, zone_largest->count); - - } - panic("zalloc: \"%s\" (%d elements) retry fail %d, kfree_nop_count: %d", zone->zone_name, zone->count, retval, (int)kfree_nop_count); - } - } else { - break; - } - } - lock_zone(zone); - - if (set_doing_alloc_with_vm_priv == TRUE) - zone->doing_alloc_with_vm_priv = FALSE; - else - zone->doing_alloc_without_vm_priv = FALSE; - - if (zone->waiting) { - zone->waiting = FALSE; - zone_wakeup(zone); - } - clear_thread_rwlock_boost(); + if (zc_magazine_size > PAGE_SIZE / ZONE_MIN_ELEM_SIZE) { + zc_magazine_size = (uint16_t)(PAGE_SIZE / ZONE_MIN_ELEM_SIZE); + } +} +STARTUP(TUNABLES, STARTUP_RANK_MIDDLE, zone_tunables_fixup); - addr = try_alloc_from_zone(zone, &check_poison); - if (addr == 0 && - retval == KERN_RESOURCE_SHORTAGE) { - if (nopagewait == TRUE) - break; /* out of the main while loop */ - unlock_zone(zone); +__startup_func +static vm_size_t +zone_phys_size_max(void) +{ + vm_size_t zsize; + vm_size_t zsizearg; - VM_PAGE_WAIT(); - lock_zone(zone); - } - } - if (addr == 0) - addr = try_alloc_from_zone(zone, &check_poison); + if (PE_parse_boot_argn("zsize", &zsizearg, sizeof(zsizearg))) { + zsize = zsizearg * (1024ULL * 1024); + } else { + /* Set target zone size as 1/4 of physical memory */ + zsize = (vm_size_t)(sane_size >> 2); +#if defined(__LP64__) + zsize += zsize >> 1; +#endif /* __LP64__ */ } -#if CONFIG_ZLEAKS - /* Zone leak detection: - * If we're sampling this allocation, add it to the zleaks hash table. - */ - if (addr && zleak_tracedepth > 0) { - /* Sampling can fail if another sample is happening at the same time in a different zone. */ - if (!zleak_log(zbt, addr, zleak_tracedepth, zone->elem_size)) { - /* If it failed, roll back the counter so we sample the next allocation instead. */ - zone->zleak_capture = zleak_sample_factor; - } + if (zsize < CONFIG_ZONE_MAP_MIN) { + zsize = CONFIG_ZONE_MAP_MIN; /* Clamp to min */ + } + if (zsize > sane_size >> 1) { + zsize = (vm_size_t)(sane_size >> 1); /* Clamp to half of RAM max */ } -#endif /* CONFIG_ZLEAKS */ - - - if ((addr == 0) && (!canblock || nopagewait) && (zone->async_pending == FALSE) && (zone->no_callout == FALSE) && (zone->exhaustible == FALSE) && (!vm_pool_low())) { - zone->async_pending = TRUE; - unlock_zone(zone); - thread_call_enter(&call_async_alloc); - lock_zone(zone); - addr = try_alloc_from_zone(zone, &check_poison); + if (zsizearg == 0 && zsize > ZONE_MAP_MAX) { + /* if zsize boot-arg not present and zsize exceeds platform maximum, clip zsize */ + printf("NOTE: zonemap size reduced from 0x%lx to 0x%lx\n", + (uintptr_t)zsize, (uintptr_t)ZONE_MAP_MAX); + zsize = ZONE_MAP_MAX; } - vm_offset_t inner_size = zone->elem_size; + return (vm_size_t)trunc_page(zsize); +} - unlock_zone(zone); +__options_decl(zone_init_allocate_flags_t, unsigned, { + ZIA_NONE = 0x00000000, + ZIA_REPLACE = 0x00000001, /* replace a previous non permanent range */ + ZIA_RANDOM = 0x00000002, /* place at a random address */ + ZIA_PERMANENT = 0x00000004, /* permanent allocation */ + ZIA_GUARD = 0x00000008, /* will be used as a guard */ +}); + +__startup_func +static struct zone_map_range +zone_init_allocate_va(vm_map_address_t addr, vm_size_t size, + zone_init_allocate_flags_t flags) +{ + vm_map_kernel_flags_t vmk_flags = VM_MAP_KERNEL_FLAGS_NONE; + int vm_alloc_flags = 0; + struct zone_map_range r; + kern_return_t kr; - if (__improbable(DO_LOGGING(zone) && addr)) { - btlog_add_entry(zone->zlog_btlog, (void *)addr, ZOP_ALLOC, (void **)zbt, numsaved); + if (flags & ZIA_REPLACE) { + vm_alloc_flags |= VM_FLAGS_FIXED | VM_FLAGS_OVERWRITE; + } else { + vm_alloc_flags |= VM_FLAGS_ANYWHERE; } - - if (__improbable(check_poison && addr)) { - vm_offset_t *element_cursor = ((vm_offset_t *) addr) + 1; - vm_offset_t *backup = get_backup_ptr(inner_size, (vm_offset_t *) addr); - - for ( ; element_cursor < backup ; element_cursor++) - if (__improbable(*element_cursor != ZP_POISON)) - zone_element_was_modified_panic(zone, - addr, - *element_cursor, - ZP_POISON, - ((vm_offset_t)element_cursor) - addr); + if (flags & ZIA_RANDOM) { + vm_alloc_flags |= VM_FLAGS_RANDOM_ADDR; + } + if (flags & ZIA_PERMANENT) { + vmk_flags.vmkf_permanent = true; } - if (addr) { - /* - * Clear out the old next pointer and backup to avoid leaking the cookie - * and so that only values on the freelist have a valid cookie - */ - - vm_offset_t *primary = (vm_offset_t *) addr; - vm_offset_t *backup = get_backup_ptr(inner_size, primary); + vm_object_reference(kernel_object); - *primary = ZP_POISON; - *backup = ZP_POISON; + kr = vm_map_enter(kernel_map, &addr, size, 0, + vm_alloc_flags, vmk_flags, VM_KERN_MEMORY_ZONE, + kernel_object, 0, FALSE, + (flags & ZIA_GUARD) ? VM_PROT_NONE : VM_PROT_DEFAULT, + (flags & ZIA_GUARD) ? VM_PROT_NONE : VM_PROT_DEFAULT, + VM_INHERIT_NONE); -#if DEBUG || DEVELOPMENT - if (__improbable(leak_scan_debug_flag && !(zone->elem_size & (sizeof(uintptr_t) - 1)))) { - int count, idx; - /* Fill element, from tail, with backtrace in reverse order */ - if (numsaved == 0) numsaved = backtrace(zbt, MAX_ZTRACE_DEPTH); - count = (int) (zone->elem_size / sizeof(uintptr_t)); - if (count >= numsaved) count = numsaved - 1; - for (idx = 0; idx < count; idx++) ((uintptr_t *)addr)[count - 1 - idx] = zbt[idx + 1]; - } -#endif /* DEBUG || DEVELOPMENT */ + if (KERN_SUCCESS != kr) { + panic("vm_map_enter(0x%zx) failed: %d", (size_t)size, kr); } - TRACE_MACHLEAKS(ZALLOC_CODE, ZALLOC_CODE_2, zone->elem_size, addr); - return((void *)addr); + r.min_address = (vm_offset_t)addr; + r.max_address = (vm_offset_t)addr + size; + return r; } - -void * -zalloc(zone_t zone) +__startup_func +static void +zone_submap_init( + vm_offset_t *submap_min, + unsigned idx, + uint64_t zone_sub_map_numer, + uint64_t *remaining_denom, + vm_offset_t *remaining_size, + vm_size_t guard_size) { - return (zalloc_internal(zone, TRUE, FALSE)); -} + vm_offset_t submap_start, submap_end; + vm_size_t submap_size; + vm_map_t submap; + kern_return_t kr; -void * -zalloc_noblock(zone_t zone) -{ - return (zalloc_internal(zone, FALSE, FALSE)); -} + submap_size = trunc_page(zone_sub_map_numer * *remaining_size / + *remaining_denom); + submap_start = *submap_min; + submap_end = submap_start + submap_size; -void * -zalloc_nopagewait(zone_t zone) -{ - return (zalloc_internal(zone, TRUE, TRUE)); -} +#if defined(__LP64__) + if (idx == Z_SUBMAP_IDX_VA_RESTRICTED) { + vm_offset_t restricted_va_max = zone_restricted_va_max(); + if (submap_end > restricted_va_max) { +#if DEBUG || DEVELOPMENT + printf("zone_init: submap[%d] clipped to %zdM of %zdM\n", idx, + (size_t)(restricted_va_max - submap_start) >> 20, + (size_t)submap_size >> 20); +#endif /* DEBUG || DEVELOPMENT */ + guard_size += submap_end - restricted_va_max; + *remaining_size -= submap_end - restricted_va_max; + submap_end = restricted_va_max; + submap_size = restricted_va_max - submap_start; + } -void * -zalloc_canblock(zone_t zone, boolean_t canblock) -{ - return (zalloc_internal(zone, canblock, FALSE)); -} + vm_packing_verify_range("vm_compressor", + submap_start, submap_end, VM_PACKING_PARAMS(C_SLOT_PACKED_PTR)); + vm_packing_verify_range("vm_page", + submap_start, submap_end, VM_PACKING_PARAMS(VM_PAGE_PACKED_PTR)); + } +#endif /* defined(__LP64__) */ + + vm_map_kernel_flags_t vmk_flags = VM_MAP_KERNEL_FLAGS_NONE; + vmk_flags.vmkf_permanent = TRUE; + kr = kmem_suballoc(kernel_map, submap_min, submap_size, + FALSE, VM_FLAGS_FIXED | VM_FLAGS_OVERWRITE, vmk_flags, + VM_KERN_MEMORY_ZONE, &submap); + if (kr != KERN_SUCCESS) { + panic("kmem_suballoc(kernel_map[%d] %p:%p) failed: %d", + idx, (void *)submap_start, (void *)submap_end, kr); + } +#if DEBUG || DEVELOPMENT + printf("zone_init: submap[%d] %p:%p (%zuM)\n", + idx, (void *)submap_start, (void *)submap_end, + (size_t)submap_size >> 20); +#endif /* DEBUG || DEVELOPMENT */ -void -zalloc_async( - __unused thread_call_param_t p0, - __unused thread_call_param_t p1) -{ - zone_t current_z = NULL; - unsigned int max_zones, i; - void *elt = NULL; - boolean_t pending = FALSE; - - simple_lock(&all_zones_lock); - max_zones = num_zones; - simple_unlock(&all_zones_lock); - for (i = 0; i < max_zones; i++) { - current_z = &(zone_array[i]); - lock_zone(current_z); - if (current_z->async_pending == TRUE) { - current_z->async_pending = FALSE; - pending = TRUE; - } - unlock_zone(current_z); + zone_init_allocate_va(submap_end, guard_size, + ZIA_PERMANENT | ZIA_GUARD | ZIA_REPLACE); - if (pending == TRUE) { - elt = zalloc_canblock(current_z, TRUE); - zfree(current_z, elt); - pending = FALSE; - } - } + zone_submaps[idx] = submap; + *submap_min = submap_end + guard_size; + *remaining_size -= submap_size; + *remaining_denom -= zone_sub_map_numer; } /* - * zget returns an element from the specified zone - * and immediately returns nothing if there is nothing there. + * Allocate metadata array and migrate foreign initial metadata. + * + * So that foreign pages and native pages have the same scheme, + * we allocate VA space that covers both foreign and native pages. */ -void * -zget( - zone_t zone) +__startup_func +static void +zone_metadata_init(void) { - return zalloc_internal(zone, FALSE, TRUE); -} + struct zone_map_range r0 = zone_info.zi_map_range[0]; + struct zone_map_range r1 = zone_info.zi_map_range[1]; + struct zone_map_range mr, br; + vm_size_t meta_size, bits_size, foreign_base; + vm_offset_t hstart, hend; + + if (r0.min_address > r1.min_address) { + r0 = zone_info.zi_map_range[1]; + r1 = zone_info.zi_map_range[0]; + } -/* Keep this FALSE by default. Large memory machine run orders of magnitude - slower in debug mode when true. Use debugger to enable if needed */ -/* static */ boolean_t zone_check = FALSE; + meta_size = round_page(atop(r1.max_address - r0.min_address) * + sizeof(struct zone_page_metadata)) + ZONE_GUARD_SIZE * 2; -static void zone_check_freelist(zone_t zone, vm_offset_t elem) -{ - struct zone_free_element *this; - struct zone_page_metadata *thispage; + /* + * Allocations can't be smaller than 8 bytes, which is 128b / 16B per 1k + * of physical memory (16M per 1G). + * + * Let's preallocate for the worst to avoid weird panics. + */ + bits_size = round_page(16 * (ptoa(zone_phys_mapped_max_pages) >> 10)); - if (zone->allows_foreign) { - for (thispage = (struct zone_page_metadata *)queue_first(&zone->pages.any_free_foreign); - !queue_end(&zone->pages.any_free_foreign, &(thispage->pages)); - thispage = (struct zone_page_metadata *)queue_next(&(thispage->pages))) { - for (this = page_metadata_get_freelist(thispage); - this != NULL; - this = this->next) { - if (!is_sane_zone_element(zone, (vm_address_t)this) || (vm_address_t)this == elem) - panic("zone_check_freelist"); - } + /* + * Compute the size of the "hole" in the middle of the range. + * + * If it is smaller than 256k, just leave it be, with this layout: + * + * [G][ r0 meta ][ hole ][ r1 meta ][ bits ][G] + * + * else punch a hole with guard pages around the hole, and place the + * bits in the hole if it fits, or after r1 otherwise, yielding either + * of the following layouts: + * + * |__________________hend____________| + * |__hstart_| | + * [G][ r0 meta ][ bits ][G]..........[G][ r1 meta ][G] + * [G][ r0 meta ][G]..................[G][ r1 meta ][ bits ][G] + */ + hstart = round_page(atop(r0.max_address - r0.min_address) * + sizeof(struct zone_page_metadata)); + hend = trunc_page(atop(r1.min_address - r0.min_address) * + sizeof(struct zone_page_metadata)); + + if (hstart >= hend || hend - hstart < (256ul << 10)) { + mr = zone_init_allocate_va(0, meta_size + bits_size, + ZIA_PERMANENT | ZIA_RANDOM); + mr.min_address += ZONE_GUARD_SIZE; + mr.max_address -= ZONE_GUARD_SIZE; + br.max_address = mr.max_address; + mr.max_address -= bits_size; + br.min_address = mr.max_address; + +#if DEBUG || DEVELOPMENT + printf("zone_init: metadata %p:%p (%zuK)\n", + (void *)mr.min_address, (void *)mr.max_address, + (size_t)zone_range_size(&mr) >> 10); + printf("zone_init: metabits %p:%p (%zuK)\n", + (void *)br.min_address, (void *)br.max_address, + (size_t)zone_range_size(&br) >> 10); +#endif /* DEBUG || DEVELOPMENT */ + } else { + vm_size_t size, alloc_size = meta_size; + vm_offset_t base; + bool bits_in_middle = true; + + if (hend - hstart - 2 * ZONE_GUARD_SIZE < bits_size) { + alloc_size += bits_size; + bits_in_middle = false; } - } - for (thispage = (struct zone_page_metadata *)queue_first(&zone->pages.all_free); - !queue_end(&zone->pages.all_free, &(thispage->pages)); - thispage = (struct zone_page_metadata *)queue_next(&(thispage->pages))) { - for (this = page_metadata_get_freelist(thispage); - this != NULL; - this = this->next) { - if (!is_sane_zone_element(zone, (vm_address_t)this) || (vm_address_t)this == elem) - panic("zone_check_freelist"); + + mr = zone_init_allocate_va(0, alloc_size, ZIA_RANDOM); + + base = mr.min_address; + size = ZONE_GUARD_SIZE + hstart + ZONE_GUARD_SIZE; + if (bits_in_middle) { + size += bits_size; + br.min_address = base + ZONE_GUARD_SIZE + hstart; + br.max_address = br.min_address + bits_size; } - } - for (thispage = (struct zone_page_metadata *)queue_first(&zone->pages.intermediate); - !queue_end(&zone->pages.intermediate, &(thispage->pages)); - thispage = (struct zone_page_metadata *)queue_next(&(thispage->pages))) { - for (this = page_metadata_get_freelist(thispage); - this != NULL; - this = this->next) { - if (!is_sane_zone_element(zone, (vm_address_t)this) || (vm_address_t)this == elem) - panic("zone_check_freelist"); + zone_init_allocate_va(base, size, ZIA_PERMANENT | ZIA_REPLACE); + + base += size; + size = mr.min_address + hend - base; + kmem_free(kernel_map, base, size); + + base = mr.min_address + hend; + size = mr.max_address - base; + zone_init_allocate_va(base, size, ZIA_PERMANENT | ZIA_REPLACE); + + mr.min_address += ZONE_GUARD_SIZE; + mr.max_address -= ZONE_GUARD_SIZE; + if (!bits_in_middle) { + br.max_address = mr.max_address; + mr.max_address -= bits_size; + br.min_address = mr.max_address; } + +#if DEBUG || DEVELOPMENT + printf("zone_init: metadata0 %p:%p (%zuK)\n", + (void *)mr.min_address, (void *)(mr.min_address + hstart), + (size_t)hstart >> 10); + printf("zone_init: metadata1 %p:%p (%zuK)\n", + (void *)(mr.min_address + hend), (void *)mr.max_address, + (size_t)(zone_range_size(&mr) - hend) >> 10); + printf("zone_init: metabits %p:%p (%zuK)\n", + (void *)br.min_address, (void *)br.max_address, + (size_t)zone_range_size(&br) >> 10); +#endif /* DEBUG || DEVELOPMENT */ } -} -void -zfree( - zone_t zone, - void *addr) -{ - vm_offset_t elem = (vm_offset_t) addr; - uintptr_t zbt[MAX_ZTRACE_DEPTH]; /* only used if zone logging is enabled via boot-args */ - int numsaved = 0; - boolean_t gzfreed = FALSE; - boolean_t poison = FALSE; + br.min_address = (br.min_address + ZBA_CHUNK_SIZE - 1) & -ZBA_CHUNK_SIZE; + br.max_address = br.max_address & -ZBA_CHUNK_SIZE; - assert(zone != ZONE_NULL); + zone_info.zi_meta_range = mr; + zone_info.zi_bits_range = br; /* - * If zone logging is turned on and this is the zone we're tracking, grab a backtrace. + * Migrate the original static metadata into its new location. */ + zone_info.zi_meta_base = (struct zone_page_metadata *)mr.min_address - + zone_pva_from_addr(r0.min_address).packed_address; + foreign_base = zone_info.zi_map_range[ZONE_ADDR_FOREIGN].min_address; + zone_meta_populate(foreign_base, zone_foreign_size()); + memcpy(zone_meta_from_addr(foreign_base), + zone_foreign_meta_array_startup, + atop(zone_foreign_size()) * sizeof(struct zone_page_metadata)); + + zba_populate(0); + memcpy(zba_base_header(), zba_chunk_startup, + sizeof(zba_chunk_startup)); +} - if (__improbable(DO_LOGGING(zone) && corruption_debug_flag)) - numsaved = OSBacktrace((void *)zbt, MAX_ZTRACE_DEPTH); - -#if MACH_ASSERT - /* Basic sanity checks */ - if (zone == ZONE_NULL || elem == (vm_offset_t)0) - panic("zfree: NULL"); -#endif - -#if CONFIG_GZALLOC - gzfreed = gzalloc_free(zone, addr); -#endif +/* Global initialization of Zone Allocator. + * Runs after zone_bootstrap. + */ +__startup_func +static void +zone_init(void) +{ + vm_size_t zone_map_size; + vm_size_t remaining_size; + vm_offset_t submap_min = 0; + uint64_t denom = 0; + uint64_t submap_ratios[Z_SUBMAP_IDX_COUNT] = { +#ifdef __LP64__ + [Z_SUBMAP_IDX_VA_RESTRICTED] = 20, +#else + [Z_SUBMAP_IDX_VA_RESERVE] = 10, +#endif /* defined(__LP64__) */ + [Z_SUBMAP_IDX_GENERAL] = 40, + [Z_SUBMAP_IDX_BAG_OF_BYTES] = 40, + }; - if (!gzfreed) { - struct zone_page_metadata *page_meta = get_zone_page_metadata((struct zone_free_element *)addr, FALSE); - if (zone != PAGE_METADATA_GET_ZONE(page_meta)) { - panic("Element %p from zone %s caught being freed to wrong zone %s\n", addr, PAGE_METADATA_GET_ZONE(page_meta)->zone_name, zone->zone_name); - } + if (ZSECURITY_OPTIONS_SUBMAP_USER_DATA & zsecurity_options) { + zone_last_submap_idx = Z_SUBMAP_IDX_BAG_OF_BYTES; + } else { + zone_last_submap_idx = Z_SUBMAP_IDX_GENERAL; } + zone_phys_mapped_max_pages = (uint32_t)atop(zone_phys_size_max()); - TRACE_MACHLEAKS(ZFREE_CODE, ZFREE_CODE_2, zone->elem_size, (uintptr_t)addr); - - if (__improbable(!gzfreed && zone->collectable && !zone->allows_foreign && - !from_zone_map(elem, zone->elem_size))) { - panic("zfree: non-allocated memory in collectable zone!"); + for (unsigned idx = 0; idx <= zone_last_submap_idx; idx++) { +#if DEBUG || DEVELOPMENT + char submap_name[1 + sizeof("submap")]; + snprintf(submap_name, sizeof(submap_name), "submap%d", idx); + PE_parse_boot_argn(submap_name, &submap_ratios[idx], sizeof(uint64_t)); +#endif + denom += submap_ratios[idx]; } - if ((zp_factor != 0 || zp_tiny_zone_limit != 0) && !gzfreed) { - /* - * Poison the memory before it ends up on the freelist to catch - * use-after-free and use of uninitialized memory - * - * Always poison tiny zones' elements (limit is 0 if -no-zp is set) - * Also poison larger elements periodically - */ - - vm_offset_t inner_size = zone->elem_size; - - uint32_t sample_factor = zp_factor + (((uint32_t)inner_size) >> zp_scale); +#if __LP64__ + zone_map_size = ZONE_MAP_VIRTUAL_SIZE_LP64; +#else + zone_map_size = ptoa(zone_phys_mapped_max_pages * + (denom + submap_ratios[Z_SUBMAP_IDX_VA_RESERVE]) / denom); +#endif - if (inner_size <= zp_tiny_zone_limit) - poison = TRUE; - else if (zp_factor != 0 && sample_counter(&zone->zp_count, sample_factor) == TRUE) - poison = TRUE; + remaining_size = zone_map_size - + ZONE_GUARD_SIZE * (zone_last_submap_idx + 1); - if (__improbable(poison)) { + /* + * And now allocate the various pieces of VA and submaps. + * + * Make a first allocation of contiguous VA, that we'll deallocate, + * and we'll carve-out memory in that range again linearly. + * The kernel is stil single threaded at this stage. + */ - /* memset_pattern{4|8} could help make this faster: */ - /* Poison everything but primary and backup */ - vm_offset_t *element_cursor = ((vm_offset_t *) elem) + 1; - vm_offset_t *backup = get_backup_ptr(inner_size, (vm_offset_t *)elem); + struct zone_map_range *map_range = + &zone_info.zi_map_range[ZONE_ADDR_NATIVE]; - for ( ; element_cursor < backup; element_cursor++) - *element_cursor = ZP_POISON; - } - } + *map_range = zone_init_allocate_va(0, zone_map_size, ZIA_NONE); + submap_min = map_range->min_address; /* - * See if we're doing logging on this zone. There are two styles of logging used depending on - * whether we're trying to catch a leak or corruption. See comments above in zalloc for details. + * Allocate the submaps */ - - if (__improbable(DO_LOGGING(zone))) { - if (corruption_debug_flag) { - /* - * We're logging to catch a corruption. Add a record of this zfree operation - * to log. - */ - btlog_add_entry(zone->zlog_btlog, (void *)addr, ZOP_FREE, (void **)zbt, numsaved); - } else { - /* - * We're logging to catch a leak. Remove any record we might have for this - * element since it's being freed. Note that we may not find it if the buffer - * overflowed and that's OK. Since the log is of a limited size, old records - * get overwritten if there are more zallocs than zfrees. - */ - btlog_remove_entries_for_element(zone->zlog_btlog, (void *)addr); - } + for (unsigned idx = 0; idx <= zone_last_submap_idx; idx++) { + zone_submap_init(&submap_min, idx, submap_ratios[idx], + &denom, &remaining_size, ZONE_GUARD_SIZE); } - lock_zone(zone); + assert(submap_min == map_range->max_address); + + zone_metadata_init(); - if (zone_check) { - zone_check_freelist(zone, elem); +#if VM_MAX_TAG_ZONES + if (zone_tagging_on) { + zone_tagging_init(zone_map_size); } +#endif +#if CONFIG_GZALLOC + gzalloc_init(zone_map_size); +#endif - if (__probable(!gzfreed)) - free_to_zone(zone, elem, poison); + zone_create_flags_t kma_flags = ZC_NOCACHING | + ZC_NOGC | ZC_NOENCRYPT | ZC_NOGZALLOC | ZC_NOCALLOUT | + ZC_KASAN_NOQUARANTINE | ZC_KASAN_NOREDZONE; -#if MACH_ASSERT - if (zone->count < 0) - panic("zfree: zone count underflow in zone %s while freeing element %p, possible cause: double frees or freeing memory that did not come from this zone", - zone->zone_name, addr); + (void)zone_create_ext("vm.permanent", 1, kma_flags, + ZONE_ID_PERMANENT, ^(zone_t z){ + z->z_permanent = true; + z->z_elem_size = 1; +#if defined(__LP64__) + z->z_submap_idx = Z_SUBMAP_IDX_VA_RESTRICTED; #endif - + }); + (void)zone_create_ext("vm.permanent.percpu", 1, kma_flags | ZC_PERCPU, + ZONE_ID_PERCPU_PERMANENT, ^(zone_t z){ + z->z_permanent = true; + z->z_elem_size = 1; +#if defined(__LP64__) + z->z_submap_idx = Z_SUBMAP_IDX_VA_RESTRICTED; +#endif + }); -#if CONFIG_ZLEAKS /* - * Zone leak detection: un-track the allocation + * Now migrate the startup statistics into their final storage. */ - if (zone->zleak_on) { - zleak_free(elem, zone->elem_size); + int cpu = cpu_number(); + zone_index_foreach(idx) { + zone_t tz = &zone_array[idx]; + + if (tz->z_stats == __zpcpu_mangle_for_boot(&zone_stats_startup[idx])) { + zone_stats_t zs = zalloc_percpu_permanent_type(struct zone_stats); + + *zpercpu_get_cpu(zs, cpu) = *zpercpu_get_cpu(tz->z_stats, cpu); + tz->z_stats = zs; +#if ZONE_ENABLE_LOGGING + if (tz->zone_logging && !tz->zlog_btlog) { + zone_enable_logging(tz); + } +#endif /* ZONE_ENABLE_LOGGING */ + } } -#endif /* CONFIG_ZLEAKS */ - - unlock_zone(zone); -} +#if CONFIG_ZLEAKS + /* + * Initialize the zone leak monitor + */ + zleak_init(zone_map_size); +#endif /* CONFIG_ZLEAKS */ -/* Change a zone's flags. - * This routine must be called immediately after zinit. - */ -void -zone_change( - zone_t zone, - unsigned int item, - boolean_t value) -{ - assert( zone != ZONE_NULL ); - assert( value == TRUE || value == FALSE ); - - switch(item){ - case Z_NOENCRYPT: - zone->noencrypt = value; - break; - case Z_EXHAUST: - zone->exhaustible = value; - break; - case Z_COLLECT: - zone->collectable = value; - break; - case Z_EXPAND: - zone->expandable = value; - break; - case Z_FOREIGN: - zone->allows_foreign = value; - break; - case Z_CALLERACCT: - zone->caller_acct = value; - break; - case Z_NOCALLOUT: - zone->no_callout = value; - break; - case Z_GZALLOC_EXEMPT: - zone->gzalloc_exempt = value; -#if CONFIG_GZALLOC - gzalloc_reconfigure(zone); -#endif - break; - case Z_ALIGNMENT_REQUIRED: - zone->alignment_required = value; -#if CONFIG_GZALLOC - gzalloc_reconfigure(zone); -#endif - break; - default: - panic("Zone_change: Wrong Item Type!"); - /* break; */ +#if VM_MAX_TAG_ZONES + if (zone_tagging_on) { + vm_allocation_zones_init(); } +#endif } +STARTUP(ZALLOC, STARTUP_RANK_FIRST, zone_init); -/* - * Return the expected number of free elements in the zone. - * This calculation will be incorrect if items are zfree'd that - * were never zalloc'd/zget'd. The correct way to stuff memory - * into a zone is by zcram. - */ - -integer_t -zone_free_count(zone_t zone) +__startup_func +static void +zone_cache_bootstrap(void) { - integer_t free_count; + zone_t magzone; - lock_zone(zone); - free_count = zone->countfree; - unlock_zone(zone); + magzone = zone_create("zcc_magazine_zone", sizeof(struct zone_magazine) + + zc_mag_size() * sizeof(zone_element_t), + ZC_NOGZALLOC | ZC_KASAN_NOREDZONE | ZC_KASAN_NOQUARANTINE | + ZC_SEQUESTER | ZC_CACHING | ZC_ZFREE_CLEARMEM); + magzone->z_elems_rsv = (uint16_t)(2 * zpercpu_count()); - assert(free_count >= 0); + os_atomic_store(&zc_magazine_zone, magzone, compiler_acq_rel); - return(free_count); + /* + * Now that we are initialized, we can enable zone caching for zones that + * were made before zcache_bootstrap() was called. + * + * The system is still single threaded so we don't need to take the lock. + */ + zone_index_foreach(i) { + zone_t z = &zone_array[i]; + if (z->z_pcpu_cache) { + z->z_pcpu_cache = NULL; + zone_enable_caching(z); + } + } } - -/* Zone garbage collection - * - * zone_gc will walk through all the free elements in all the - * zones that are marked collectable looking for reclaimable - * pages. zone_gc is called by consider_zone_gc when the system - * begins to run out of memory. - */ -extern zone_t vm_map_entry_reserved_zone; -uint64_t zone_gc_bailed = 0; +STARTUP(ZALLOC, STARTUP_RANK_FOURTH, zone_cache_bootstrap); void -zone_gc(void) +zalloc_first_proc_made(void) { - unsigned int max_zones; - zone_t z; - unsigned int i; - zone_t zres = vm_map_entry_reserved_zone; - - lck_mtx_lock(&zone_gc_lock); - - simple_lock(&all_zones_lock); - max_zones = num_zones; - simple_unlock(&all_zones_lock); - - if (zalloc_debug & ZALLOC_DEBUG_ZONEGC) - kprintf("zone_gc() starting...\n"); - - for (i = 0; i < max_zones; i++) { - z = &(zone_array[i]); - vm_size_t elt_size, size_freed; - int total_freed_pages = 0; - struct zone_page_metadata *page_meta; - queue_head_t page_meta_head; - - assert(z != ZONE_NULL); + zone_caching_disabled = 0; +} - if (!z->collectable) - continue; - - if (queue_empty(&z->pages.all_free)) { - continue; - } - - /* - * Since kmem_free() might use VM entries from the reserved VM entries zone, we should bail from zone_gc() if we - * are below the critical threshold for that zone. Otherwise, there could be a deadlock between the zone_gc - * thread and the zone_replenish thread for the VM entries zone on the zone_map lock. - */ - if (zres->zone_replenishing) { - zone_gc_bailed++; - break; - } +__startup_func +vm_offset_t +zone_foreign_mem_init(vm_size_t size) +{ + vm_offset_t mem; - lock_zone(z); - elt_size = z->elem_size; + if (atop(size) > ZONE_FOREIGN_META_INLINE_COUNT) { + panic("ZONE_FOREIGN_META_INLINE_COUNT has become too small: " + "%d > %d", (int)atop(size), ZONE_FOREIGN_META_INLINE_COUNT); + } - if (queue_empty(&z->pages.all_free)) { - unlock_zone(z); - continue; - } + mem = (vm_offset_t)pmap_steal_memory(size); - /* - * Snatch all of the free elements away from the zone. - */ - uint64_t old_all_free_count = z->count_all_free_pages; - queue_new_head(&z->pages.all_free, &page_meta_head, struct zone_page_metadata *, pages); - queue_init(&z->pages.all_free); - z->count_all_free_pages = 0; - unlock_zone(z); - - /* Iterate through all elements to find out size and count of elements we snatched */ - size_freed = 0; - queue_iterate(&page_meta_head, page_meta, struct zone_page_metadata *, pages) { - assert(from_zone_map((vm_address_t)page_meta, sizeof(*page_meta))); /* foreign elements should be in any_free_foreign */ - size_freed += elt_size * page_meta->free_count; - } - - /* Update the zone size and free element count */ - lock_zone(z); - z->cur_size -= size_freed; - z->countfree -= size_freed/elt_size; - unlock_zone(z); - - while ((page_meta = (struct zone_page_metadata *)dequeue_head(&page_meta_head)) != NULL) { - vm_address_t free_page_address; - if (zres->zone_replenishing) - break; - /* Free the pages for metadata and account for them */ - free_page_address = get_zone_page(page_meta); - ZONE_PAGE_COUNT_DECR(z, page_meta->page_count); - total_freed_pages += page_meta->page_count; - old_all_free_count -= page_meta->page_count; - size_freed -= (elt_size * page_meta->free_count); - kmem_free(zone_map, free_page_address, (page_meta->page_count * PAGE_SIZE)); - thread_yield_to_preemption(); - } - if (page_meta != NULL) { - /* - * We bailed because the VM entry reserved zone is replenishing. Put the remaining - * metadata objects back on the all_free list and bail. - */ - queue_entry_t qe; - enqueue_head(&page_meta_head, &(page_meta->pages)); - zone_gc_bailed++; - - lock_zone(z); - qe_foreach_safe(qe, &page_meta_head) { - re_queue_tail(&z->pages.all_free, qe); - } - z->count_all_free_pages += (int)old_all_free_count; - z->cur_size += size_freed; - z->countfree += size_freed/elt_size; - unlock_zone(z); - if (zalloc_debug & ZALLOC_DEBUG_ZONEGC) - kprintf("zone_gc() bailed due to VM entry zone replenishing (zone_gc_bailed: %lld)\n", zone_gc_bailed); - break; - } - - /* We freed all the pages from the all_free list for this zone */ - assert(old_all_free_count == 0); + zone_info.zi_meta_base = zone_foreign_meta_array_startup - + zone_pva_from_addr(mem).packed_address; + zone_info.zi_map_range[ZONE_ADDR_FOREIGN].min_address = mem; + zone_info.zi_map_range[ZONE_ADDR_FOREIGN].max_address = mem + size; - if (zalloc_debug & ZALLOC_DEBUG_ZONEGC) - kprintf("zone_gc() of zone %s freed %lu elements, %d pages\n", z->zone_name, (unsigned long)size_freed/elt_size, total_freed_pages); - } + zone_info.zi_bits_range = (struct zone_map_range){ + .min_address = (vm_offset_t)zba_chunk_startup, + .max_address = (vm_offset_t)zba_chunk_startup + + sizeof(zba_chunk_startup), + }; + zba_init_chunk(0); - lck_mtx_unlock(&zone_gc_lock); + return mem; } -extern vm_offset_t kmapoff_kaddr; -extern unsigned int kmapoff_pgcnt; +#endif /* !ZALLOC_TEST */ +#pragma mark - tests +#if DEBUG || DEVELOPMENT /* - * consider_zone_gc: - * - * Called by the pageout daemon when the system needs more free pages. + * Used for sysctl kern.run_zone_test which is not thread-safe. Ensure only one + * thread goes through at a time. Or we can end up with multiple test zones (if + * a second zinit() comes through before zdestroy()), which could lead us to + * run out of zones. */ +static SIMPLE_LOCK_DECLARE(zone_test_lock, 0); +static boolean_t zone_test_running = FALSE; +static zone_t test_zone_ptr = NULL; -void -consider_zone_gc(void) +static uintptr_t * +zone_copy_allocations(zone_t z, uintptr_t *elems, zone_pva_t page_index) { - if (kmapoff_kaddr != 0) { - /* - * One-time reclaim of kernel_map resources we allocated in - * early boot. - */ - (void) vm_deallocate(kernel_map, - kmapoff_kaddr, kmapoff_pgcnt * PAGE_SIZE_64); - kmapoff_kaddr = 0; - } - - if (zone_gc_allowed) - zone_gc(); -} + vm_offset_t elem_size = zone_elem_size(z); + vm_offset_t base; + struct zone_page_metadata *meta; -kern_return_t -task_zone_info( - __unused task_t task, - __unused mach_zone_name_array_t *namesp, - __unused mach_msg_type_number_t *namesCntp, - __unused task_zone_info_array_t *infop, - __unused mach_msg_type_number_t *infoCntp) -{ - return KERN_FAILURE; -} + while (!zone_pva_is_null(page_index)) { + base = zone_pva_to_addr(page_index); + meta = zone_pva_to_meta(page_index); -kern_return_t -mach_zone_info( - host_priv_t host, - mach_zone_name_array_t *namesp, - mach_msg_type_number_t *namesCntp, - mach_zone_info_array_t *infop, - mach_msg_type_number_t *infoCntp) -{ - return (mach_memory_info(host, namesp, namesCntp, infop, infoCntp, NULL, NULL)); -} + if (meta->zm_inline_bitmap) { + for (size_t i = 0; i < meta->zm_chunk_len; i++) { + uint32_t map = meta[i].zm_bitmap; + for (; map; map &= map - 1) { + *elems++ = INSTANCE_PUT(base + + elem_size * __builtin_clz(map)); + } + base += elem_size * 32; + } + } else { + uint32_t order = zba_bits_ref_order(meta->zm_bitmap); + bitmap_t *bits = zba_bits_ref_ptr(meta->zm_bitmap); + for (size_t i = 0; i < (1u << order); i++) { + uint64_t map = bits[i]; + + for (; map; map &= map - 1) { + *elems++ = INSTANCE_PUT(base + + elem_size * __builtin_clzll(map)); + } + base += elem_size * 64; + } + } -kern_return_t -host_zone_info( - host_priv_t host, - zone_name_array_t *namesp, - mach_msg_type_number_t *namesCntp, - zone_info_array_t *infop, - mach_msg_type_number_t *infoCntp) -{ - return (mach_memory_info(host, (mach_zone_name_array_t *)namesp, namesCntp, (mach_zone_info_array_t *)infop, infoCntp, NULL, NULL)); + page_index = meta->zm_page_next; + } + return elems; } kern_return_t -mach_memory_info( - host_priv_t host, - mach_zone_name_array_t *namesp, - mach_msg_type_number_t *namesCntp, - mach_zone_info_array_t *infop, - mach_msg_type_number_t *infoCntp, - mach_memory_info_array_t *memoryInfop, - mach_msg_type_number_t *memoryInfoCntp) +zone_leaks(const char * zoneName, uint32_t nameLen, leak_site_proc proc, void * refCon) { - mach_zone_name_t *names; - vm_offset_t names_addr; - vm_size_t names_size; - - mach_zone_info_t *info; - vm_offset_t info_addr; - vm_size_t info_size; - - mach_memory_info_t *memory_info; - vm_offset_t memory_info_addr; - vm_size_t memory_info_size; - vm_size_t memory_info_vmsize; - unsigned int num_sites; - - unsigned int max_zones, i; - zone_t z; - mach_zone_name_t *zn; - mach_zone_info_t *zi; - kern_return_t kr; - - vm_size_t used; - vm_map_copy_t copy; - uint64_t zones_collectable_bytes = 0; - - if (host == HOST_NULL) - return KERN_INVALID_HOST; -#if CONFIG_DEBUGGER_FOR_ZONE_INFO - if (!PE_i_can_has_debugger(NULL)) - return KERN_INVALID_HOST; -#endif - - /* - * We assume that zones aren't freed once allocated. - * We won't pick up any zones that are allocated later. - */ - - simple_lock(&all_zones_lock); - max_zones = (unsigned int)(num_zones); - simple_unlock(&all_zones_lock); - - names_size = round_page(max_zones * sizeof *names); - kr = kmem_alloc_pageable(ipc_kernel_map, - &names_addr, names_size, VM_KERN_MEMORY_IPC); - if (kr != KERN_SUCCESS) - return kr; - names = (mach_zone_name_t *) names_addr; - - info_size = round_page(max_zones * sizeof *info); - kr = kmem_alloc_pageable(ipc_kernel_map, - &info_addr, info_size, VM_KERN_MEMORY_IPC); - if (kr != KERN_SUCCESS) { - kmem_free(ipc_kernel_map, - names_addr, names_size); - return kr; + uintptr_t zbt[MAX_ZTRACE_DEPTH]; + zone_t zone = NULL; + uintptr_t * array; + uintptr_t * next; + uintptr_t element, bt; + uint32_t idx, count, found; + uint32_t btidx, btcount, nobtcount, btfound; + uint32_t elemSize; + size_t maxElems; + kern_return_t kr; + + zone_foreach(z) { + if (!strncmp(zoneName, z->z_name, nameLen)) { + zone = z; + break; + } } - info = (mach_zone_info_t *) info_addr; - - zn = &names[0]; - zi = &info[0]; - - for (i = 0; i < max_zones; i++) { - struct zone zcopy; - z = &(zone_array[i]); - assert(z != ZONE_NULL); - - lock_zone(z); - zcopy = *z; - unlock_zone(z); - - /* assuming here the name data is static */ - (void) strncpy(zn->mzn_name, zcopy.zone_name, - sizeof zn->mzn_name); - zn->mzn_name[sizeof zn->mzn_name - 1] = '\0'; - - zi->mzi_count = (uint64_t)zcopy.count; - zi->mzi_cur_size = ptoa_64(zcopy.page_count); - zi->mzi_max_size = (uint64_t)zcopy.max_size; - zi->mzi_elem_size = (uint64_t)zcopy.elem_size; - zi->mzi_alloc_size = (uint64_t)zcopy.alloc_size; - zi->mzi_sum_size = zcopy.sum_count * zcopy.elem_size; - zi->mzi_exhaustible = (uint64_t)zcopy.exhaustible; - zi->mzi_collectable = (uint64_t)zcopy.collectable; - zones_collectable_bytes += ((uint64_t)zcopy.count_all_free_pages * PAGE_SIZE); - zn++; - zi++; + if (zone == NULL) { + return KERN_INVALID_NAME; } - used = max_zones * sizeof *names; - if (used != names_size) - bzero((char *) (names_addr + used), names_size - used); + elemSize = (uint32_t)zone_elem_size(zone); + maxElems = (zone->z_elems_avail + 1) & ~1ul; - kr = vm_map_copyin(ipc_kernel_map, (vm_map_address_t)names_addr, - (vm_map_size_t)used, TRUE, ©); - assert(kr == KERN_SUCCESS); + if ((ptoa(zone->z_percpu ? 1 : zone->z_chunk_pages) % elemSize) && + !zone_leaks_scan_enable) { + return KERN_INVALID_CAPABILITY; + } - *namesp = (mach_zone_name_t *) copy; - *namesCntp = max_zones; + kr = kmem_alloc_kobject(kernel_map, (vm_offset_t *) &array, + maxElems * sizeof(uintptr_t), VM_KERN_MEMORY_DIAG); + if (KERN_SUCCESS != kr) { + return kr; + } - used = max_zones * sizeof *info; + zone_lock(zone); - if (used != info_size) - bzero((char *) (info_addr + used), info_size - used); + next = array; + next = zone_copy_allocations(zone, next, zone->z_pageq_partial); + next = zone_copy_allocations(zone, next, zone->z_pageq_full); + count = (uint32_t)(next - array); - kr = vm_map_copyin(ipc_kernel_map, (vm_map_address_t)info_addr, - (vm_map_size_t)used, TRUE, ©); - assert(kr == KERN_SUCCESS); + zone_unlock(zone); - *infop = (mach_zone_info_t *) copy; - *infoCntp = max_zones; - - num_sites = 0; - memory_info_addr = 0; + zone_leaks_scan(array, count, (uint32_t)zone_elem_size(zone), &found); + assert(found <= count); - if (memoryInfop && memoryInfoCntp) - { - num_sites = VM_KERN_MEMORY_COUNT + VM_KERN_COUNTER_COUNT; - memory_info_size = num_sites * sizeof(*info); - memory_info_vmsize = round_page(memory_info_size); - kr = kmem_alloc_pageable(ipc_kernel_map, - &memory_info_addr, memory_info_vmsize, VM_KERN_MEMORY_IPC); - if (kr != KERN_SUCCESS) { - kmem_free(ipc_kernel_map, - names_addr, names_size); - kmem_free(ipc_kernel_map, - info_addr, info_size); - return kr; + for (idx = 0; idx < count; idx++) { + element = array[idx]; + if (kInstanceFlagReferenced & element) { + continue; } + element = INSTANCE_PUT(element) & ~kInstanceFlags; + } - kr = vm_map_wire(ipc_kernel_map, memory_info_addr, memory_info_addr + memory_info_vmsize, - VM_PROT_READ|VM_PROT_WRITE|VM_PROT_MEMORY_TAG_MAKE(VM_KERN_MEMORY_IPC), FALSE); - assert(kr == KERN_SUCCESS); - - memory_info = (mach_memory_info_t *) memory_info_addr; - vm_page_diagnose(memory_info, num_sites, zones_collectable_bytes); +#if ZONE_ENABLE_LOGGING + if (zone->zlog_btlog && !corruption_debug_flag) { + // btlog_copy_backtraces_for_elements will set kInstanceFlagReferenced on elements it found + btlog_copy_backtraces_for_elements(zone->zlog_btlog, array, &count, elemSize, proc, refCon); + } +#endif /* ZONE_ENABLE_LOGGING */ - kr = vm_map_unwire(ipc_kernel_map, memory_info_addr, memory_info_addr + memory_info_vmsize, FALSE); - assert(kr == KERN_SUCCESS); - - kr = vm_map_copyin(ipc_kernel_map, (vm_map_address_t)memory_info_addr, - (vm_map_size_t)memory_info_size, TRUE, ©); - assert(kr == KERN_SUCCESS); + for (nobtcount = idx = 0; idx < count; idx++) { + element = array[idx]; + if (!element) { + continue; + } + if (kInstanceFlagReferenced & element) { + continue; + } + element = INSTANCE_PUT(element) & ~kInstanceFlags; - *memoryInfop = (mach_memory_info_t *) copy; - *memoryInfoCntp = num_sites; + // see if we can find any backtrace left in the element + btcount = (typeof(btcount))(zone_elem_size(zone) / sizeof(uintptr_t)); + if (btcount >= MAX_ZTRACE_DEPTH) { + btcount = MAX_ZTRACE_DEPTH - 1; + } + for (btfound = btidx = 0; btidx < btcount; btidx++) { + bt = ((uintptr_t *)element)[btcount - 1 - btidx]; + if (!VM_KERNEL_IS_SLID(bt)) { + break; + } + zbt[btfound++] = bt; + } + if (btfound) { + (*proc)(refCon, 1, elemSize, &zbt[0], btfound); + } else { + nobtcount++; + } + } + if (nobtcount) { + // fake backtrace when we found nothing + zbt[0] = (uintptr_t) &zalloc; + (*proc)(refCon, nobtcount, elemSize, &zbt[0], 1); } + kmem_free(kernel_map, (vm_offset_t) array, maxElems * sizeof(uintptr_t)); + return KERN_SUCCESS; } -kern_return_t -mach_zone_force_gc( - host_t host) +boolean_t +run_zone_test(void) { + unsigned int i = 0, max_iter = 5; + void * test_ptr; + zone_t test_zone; + zone_t test_pcpu_zone; + kern_return_t kr; + + simple_lock(&zone_test_lock, &zone_locks_grp); + if (!zone_test_running) { + zone_test_running = TRUE; + } else { + simple_unlock(&zone_test_lock); + printf("run_zone_test: Test already running.\n"); + return FALSE; + } + simple_unlock(&zone_test_lock); - if (host == HOST_NULL) - return KERN_INVALID_HOST; - - consider_zone_gc(); - - return (KERN_SUCCESS); -} + printf("run_zone_test: Testing zinit(), zalloc(), zfree() and zdestroy() on zone \"test_zone_sysctl\"\n"); -extern unsigned int stack_total; -extern unsigned long long stack_allocs; + /* zinit() and zdestroy() a zone with the same name a bunch of times, verify that we get back the same zone each time */ + do { + test_zone = zinit(sizeof(uint64_t), 100 * sizeof(uint64_t), sizeof(uint64_t), "test_zone_sysctl"); + if (test_zone == NULL) { + printf("run_zone_test: zinit() failed\n"); + return FALSE; + } -#if defined(__i386__) || defined (__x86_64__) -extern unsigned int inuse_ptepages_count; -extern long long alloc_ptepages_count; +#if KASAN_ZALLOC + if (test_zone_ptr == NULL && test_zone->z_elems_free != 0) { +#else + if (test_zone->z_elems_free != 0) { #endif + printf("run_zone_test: free count is not zero\n"); + return FALSE; + } -void zone_display_zprint() -{ - unsigned int i; - zone_t the_zone; + if (test_zone_ptr == NULL) { + /* Stash the zone pointer returned on the fist zinit */ + printf("run_zone_test: zone created for the first time\n"); + test_zone_ptr = test_zone; + } else if (test_zone != test_zone_ptr) { + printf("run_zone_test: old zone pointer and new zone pointer don't match\n"); + return FALSE; + } - for (i = 0; i < num_zones; i++) { - the_zone = &(zone_array[i]); - if(the_zone->cur_size > (1024*1024)) { - printf("%.20s:\t%lu\n",the_zone->zone_name,(uintptr_t)the_zone->cur_size); + test_ptr = zalloc(test_zone); + if (test_ptr == NULL) { + printf("run_zone_test: zalloc() failed\n"); + return FALSE; } - } - printf("Kernel Stacks:\t%lu\n",(uintptr_t)(kernel_stack_size * stack_total)); + zfree(test_zone, test_ptr); + + zdestroy(test_zone); + i++; + + printf("run_zone_test: Iteration %d successful\n", i); + } while (i < max_iter); + + /* test Z_VA_SEQUESTER */ + if (zsecurity_options & ZSECURITY_OPTIONS_SEQUESTER) { + int idx, num_allocs = 8; + vm_size_t elem_size = 2 * PAGE_SIZE / num_allocs; + void *allocs[num_allocs]; + void **allocs_pcpu; + vm_offset_t phys_pages = os_atomic_load(&zones_phys_page_mapped_count, relaxed); + + test_zone = zone_create("test_zone_sysctl", elem_size, + ZC_DESTRUCTIBLE | ZC_SEQUESTER); + assert(test_zone); + + test_pcpu_zone = zone_create("test_zone_sysctl.pcpu", sizeof(uint64_t), + ZC_DESTRUCTIBLE | ZC_SEQUESTER | ZC_PERCPU); + assert(test_pcpu_zone); + + for (idx = 0; idx < num_allocs; idx++) { + allocs[idx] = zalloc(test_zone); + assert(NULL != allocs[idx]); + printf("alloc[%d] %p\n", idx, allocs[idx]); + } + for (idx = 0; idx < num_allocs; idx++) { + zfree(test_zone, allocs[idx]); + } + assert(!zone_pva_is_null(test_zone->z_pageq_empty)); -#if defined(__i386__) || defined (__x86_64__) - printf("PageTables:\t%lu\n",(uintptr_t)(PAGE_SIZE * inuse_ptepages_count)); -#endif + kr = kernel_memory_allocate(kernel_map, + (vm_address_t *)&allocs_pcpu, PAGE_SIZE, + 0, KMA_ZERO | KMA_KOBJECT, VM_KERN_MEMORY_DIAG); + assert(kr == KERN_SUCCESS); - printf("Kalloc.Large:\t%lu\n",(uintptr_t)kalloc_large_total); -} + for (idx = 0; idx < PAGE_SIZE / sizeof(uint64_t); idx++) { + allocs_pcpu[idx] = zalloc_percpu(test_pcpu_zone, + Z_WAITOK | Z_ZERO); + assert(NULL != allocs_pcpu[idx]); + } + for (idx = 0; idx < PAGE_SIZE / sizeof(uint64_t); idx++) { + zfree_percpu(test_pcpu_zone, allocs_pcpu[idx]); + } + assert(!zone_pva_is_null(test_pcpu_zone->z_pageq_empty)); + + printf("vm_page_wire_count %d, vm_page_free_count %d, p to v %ld%%\n", + vm_page_wire_count, vm_page_free_count, + 100L * phys_pages / zone_phys_mapped_max_pages); + zone_gc(ZONE_GC_DRAIN); + printf("vm_page_wire_count %d, vm_page_free_count %d, p to v %ld%%\n", + vm_page_wire_count, vm_page_free_count, + 100L * phys_pages / zone_phys_mapped_max_pages); + + unsigned int allva = 0; + + zone_foreach(z) { + zone_lock(z); + allva += z->z_wired_cur; + if (zone_pva_is_null(z->z_pageq_va)) { + zone_unlock(z); + continue; + } + unsigned count = 0; + uint64_t size; + zone_pva_t pg = z->z_pageq_va; + struct zone_page_metadata *page_meta; + while (pg.packed_address) { + page_meta = zone_pva_to_meta(pg); + count += z->z_percpu ? 1 : z->z_chunk_pages; + if (page_meta->zm_chunk_len == ZM_SECONDARY_PAGE) { + count -= page_meta->zm_page_index; + } + pg = page_meta->zm_page_next; + } + assert(z->z_wired_cur + count == z->z_va_cur); + size = zone_size_wired(z); + if (!size) { + size = 1; + } + printf("%s%s: seq %d, res %d, %qd %%\n", + zone_heap_name(z), z->z_name, z->z_va_cur - z->z_wired_cur, + z->z_wired_cur, zone_size_allocated(z) * 100ULL / size); + zone_unlock(z); + } -zone_t -zone_find_largest(void) -{ - unsigned int i; - unsigned int max_zones; - zone_t the_zone; - zone_t zone_largest; + printf("total va: %d\n", allva); - simple_lock(&all_zones_lock); - max_zones = num_zones; - simple_unlock(&all_zones_lock); - - zone_largest = &(zone_array[0]); - for (i = 0; i < max_zones; i++) { - the_zone = &(zone_array[i]); - if (the_zone->cur_size > zone_largest->cur_size) { - zone_largest = the_zone; + assert(zone_pva_is_null(test_zone->z_pageq_empty)); + assert(zone_pva_is_null(test_zone->z_pageq_partial)); + assert(!zone_pva_is_null(test_zone->z_pageq_va)); + assert(zone_pva_is_null(test_pcpu_zone->z_pageq_empty)); + assert(zone_pva_is_null(test_pcpu_zone->z_pageq_partial)); + assert(!zone_pva_is_null(test_pcpu_zone->z_pageq_va)); + + for (idx = 0; idx < num_allocs; idx++) { + assert(0 == pmap_find_phys(kernel_pmap, (addr64_t)(uintptr_t) allocs[idx])); } - } - return zone_largest; -} -#if ZONE_DEBUG + /* make sure the zone is still usable after a GC */ -/* should we care about locks here ? */ + for (idx = 0; idx < num_allocs; idx++) { + allocs[idx] = zalloc(test_zone); + assert(allocs[idx]); + printf("alloc[%d] %p\n", idx, allocs[idx]); + } + assert(zone_pva_is_null(test_zone->z_pageq_va)); + assert(test_zone->z_wired_cur == test_zone->z_va_cur); + for (idx = 0; idx < num_allocs; idx++) { + zfree(test_zone, allocs[idx]); + } -#define zone_in_use(z) ( z->count || z->free_elements \ - || !queue_empty(&z->pages.all_free) \ - || !queue_empty(&z->pages.intermediate) \ - || (z->allows_foreign && !queue_empty(&z->pages.any_free_foreign))) + for (idx = 0; idx < PAGE_SIZE / sizeof(uint64_t); idx++) { + allocs_pcpu[idx] = zalloc_percpu(test_pcpu_zone, + Z_WAITOK | Z_ZERO); + assert(NULL != allocs_pcpu[idx]); + } + for (idx = 0; idx < PAGE_SIZE / sizeof(uint64_t); idx++) { + zfree_percpu(test_pcpu_zone, allocs_pcpu[idx]); + } + assert(!zone_pva_is_null(test_pcpu_zone->z_pageq_empty)); + assert(zone_pva_is_null(test_pcpu_zone->z_pageq_va)); -#endif /* ZONE_DEBUG */ + kmem_free(kernel_map, (vm_address_t)allocs_pcpu, PAGE_SIZE); + zdestroy(test_zone); + zdestroy(test_pcpu_zone); + } else { + printf("run_zone_test: skipping sequester test (not enabled)\n"); + } -/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + printf("run_zone_test: Test passed\n"); -#if DEBUG || DEVELOPMENT + simple_lock(&zone_test_lock, &zone_locks_grp); + zone_test_running = FALSE; + simple_unlock(&zone_test_lock); -static uintptr_t * -zone_copy_all_allocations_inqueue(zone_t z, queue_head_t * queue, uintptr_t * elems) -{ - struct zone_page_metadata *page_meta; - vm_offset_t free, elements; - vm_offset_t idx, numElements, freeCount, bytesAvail, metaSize; - - queue_iterate(queue, page_meta, struct zone_page_metadata *, pages) - { - elements = get_zone_page(page_meta); - bytesAvail = ptoa(page_meta->page_count); - freeCount = 0; - if (z->allows_foreign && !from_zone_map(elements, z->elem_size)) - { - metaSize = (sizeof(struct zone_page_metadata) + ZONE_ELEMENT_ALIGNMENT - 1) & ~(ZONE_ELEMENT_ALIGNMENT - 1); - bytesAvail -= metaSize; - elements += metaSize; - } - numElements = bytesAvail / z->elem_size; - // construct array of all possible elements - for (idx = 0; idx < numElements; idx++) - { - elems[idx] = INSTANCE_PUT(elements + idx * z->elem_size); - } - // remove from the array all free elements - free = (vm_offset_t)page_metadata_get_freelist(page_meta); - while (free) - { - // find idx of free element - for (idx = 0; (idx < numElements) && (elems[idx] != INSTANCE_PUT(free)); idx++) {} - assert(idx < numElements); - // remove it - bcopy(&elems[idx + 1], &elems[idx], (numElements - (idx + 1)) * sizeof(elems[0])); - numElements--; - freeCount++; - // next free element - vm_offset_t *primary = (vm_offset_t *) free; - free = *primary ^ zp_nopoison_cookie; - } - elems += numElements; - } - - return (elems); + return TRUE; } -kern_return_t -zone_leaks(const char * zoneName, uint32_t nameLen, leak_site_proc proc, void * refCon) -{ - uintptr_t zbt[MAX_ZTRACE_DEPTH]; - zone_t zone; - uintptr_t * array; - uintptr_t * next; - uintptr_t element, bt; - uint32_t idx, count, found; - uint32_t btidx, btcount, nobtcount, btfound; - uint32_t elemSize; - uint64_t maxElems; - kern_return_t kr; - - for (idx = 0; idx < num_zones; idx++) - { - if (!strncmp(zoneName, zone_array[idx].zone_name, nameLen)) break; - } - if (idx >= num_zones) return (KERN_INVALID_NAME); - zone = &zone_array[idx]; - - elemSize = (uint32_t) zone->elem_size; - maxElems = ptoa(zone->page_count) / elemSize; - - if ((zone->alloc_size % elemSize) - && !leak_scan_debug_flag) return (KERN_INVALID_CAPABILITY); - - kr = kmem_alloc_kobject(kernel_map, (vm_offset_t *) &array, - maxElems * sizeof(uintptr_t), VM_KERN_MEMORY_DIAG); - if (KERN_SUCCESS != kr) return (kr); - - lock_zone(zone); - - next = array; - next = zone_copy_all_allocations_inqueue(zone, &zone->pages.any_free_foreign, next); - next = zone_copy_all_allocations_inqueue(zone, &zone->pages.intermediate, next); - next = zone_copy_all_allocations_inqueue(zone, &zone->pages.all_used, next); - count = (uint32_t)(next - array); - - unlock_zone(zone); - - zone_leaks_scan(array, count, (uint32_t)zone->elem_size, &found); - assert(found <= count); - - for (idx = 0; idx < count; idx++) - { - element = array[idx]; - if (kInstanceFlagReferenced & element) continue; - element = INSTANCE_PUT(element) & ~kInstanceFlags; - } - - if (zone->zlog_btlog && !corruption_debug_flag) - { - // btlog_copy_backtraces_for_elements will set kInstanceFlagReferenced on elements it found - btlog_copy_backtraces_for_elements(zone->zlog_btlog, array, &count, elemSize, proc, refCon); - } - - for (nobtcount = idx = 0; idx < count; idx++) - { - element = array[idx]; - if (!element) continue; - if (kInstanceFlagReferenced & element) continue; - element = INSTANCE_PUT(element) & ~kInstanceFlags; - - // see if we can find any backtrace left in the element - btcount = (typeof(btcount)) (zone->elem_size / sizeof(uintptr_t)); - if (btcount >= MAX_ZTRACE_DEPTH) btcount = MAX_ZTRACE_DEPTH - 1; - for (btfound = btidx = 0; btidx < btcount; btidx++) - { - bt = ((uintptr_t *)element)[btcount - 1 - btidx]; - if (!VM_KERNEL_IS_SLID(bt)) break; - zbt[btfound++] = bt; - } - if (btfound) (*proc)(refCon, 1, elemSize, &zbt[0], btfound); - else nobtcount++; - } - if (nobtcount) - { - // fake backtrace when we found nothing - zbt[0] = (uintptr_t) &zalloc; - (*proc)(refCon, nobtcount, elemSize, &zbt[0], 1); - } - - kmem_free(kernel_map, (vm_offset_t) array, maxElems * sizeof(uintptr_t)); - - return (KERN_SUCCESS); -} +/* + * Routines to test that zone garbage collection and zone replenish threads + * running at the same time don't cause problems. + */ void -kern_wired_diagnose(void) +zone_gc_replenish_test(void) { - unsigned int count = VM_KERN_MEMORY_COUNT + VM_KERN_COUNTER_COUNT; - mach_memory_info_t info[count]; - unsigned int idx; - uint64_t total_zone, total_wired, top_wired, osfmk_wired; + zone_gc(ZONE_GC_DRAIN); +} - if (KERN_SUCCESS != vm_page_diagnose(info, count, 0)) return; - total_zone = total_wired = top_wired = osfmk_wired = 0; - for (idx = 0; idx < num_zones; idx++) - { - total_zone += ptoa_64(zone_array[idx].page_count); - } - total_wired = total_zone; +void +zone_alloc_replenish_test(void) +{ + zone_t z = NULL; + struct data { struct data *next; } *node, *list = NULL; - for (idx = 0; idx < count; idx++) - { - if (VM_KERN_COUNT_WIRED == info[idx].site) top_wired = info[idx].size; - if (VM_KERN_MEMORY_OSFMK == info[idx].site) osfmk_wired = info[idx].size; - if (VM_KERN_SITE_HIDE & info[idx].flags) continue; - if (!(VM_KERN_SITE_WIRED & info[idx].flags)) continue; - total_wired += info[idx].size; - } + /* + * Find a zone that has a replenish thread + */ + zone_index_foreach(i) { + z = &zone_array[i]; + if (z->z_replenishes && zone_elem_size(z) >= sizeof(struct data)) { + z = &zone_array[i]; + break; + } + } + if (z == NULL) { + printf("Couldn't find a replenish zone\n"); + return; + } - printf("top 0x%qx, total 0x%qx, zone 0x%qx, osfmk 0x%qx\n", - top_wired, total_wired, total_zone, osfmk_wired); -} + for (uint32_t i = 0; i < 2000; ++i) { /* something big enough to go past replenishment */ + node = zalloc(z); + node->next = list; + list = node; + } -boolean_t -kdp_is_in_zone(void *addr, const char *zone_name) -{ - zone_t z; - return (zone_element_size(addr, &z) && !strcmp(z->zone_name, zone_name)); + /* + * release the memory we allocated + */ + while (list != NULL) { + node = list; + list = list->next; + zfree(z, node); + } } #endif /* DEBUG || DEVELOPMENT */