+ 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_OSFMK);
+ if (retval != KERN_SUCCESS) {
+ goto fail;
+ }
+
+ retval = kmem_alloc_kobject(kernel_map, (vm_offset_t*)&traces_ptr, z_trace_size, VM_KERN_MEMORY_OSFMK);
+ 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;
+}
+
+/*
+ * 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.
+ */
+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);
+ }
+}
+
+#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.
+ */
+
+/* "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;
+}
+
+/* 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)
+
+/* Used to manage copying in of new zone names */
+static vm_offset_t zone_names_start;
+static vm_offset_t zone_names_next;
+
+static vm_size_t
+compute_element_size(vm_size_t requested_size)
+{
+ vm_size_t element_size = requested_size;
+
+ /* Zone elements must fit both a next pointer and a backup pointer */
+ vm_size_t minimum_element_size = sizeof(vm_offset_t) * 2;
+ if (element_size < minimum_element_size)
+ element_size = minimum_element_size;
+
+ /*
+ * Round element size to a multiple of sizeof(pointer)
+ * This also enforces that allocations will be aligned on pointer boundaries
+ */
+ element_size = ((element_size-1) + sizeof(vm_offset_t)) -
+ ((element_size-1) % sizeof(vm_offset_t));
+
+ return element_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_t z;
+
+ size = compute_element_size(size);
+
+ simple_lock(&all_zones_lock);
+
+ assert(num_zones < MAX_ZONES);
+ assert(num_zones_in_use <= num_zones);
+
+ /* If possible, find a previously zdestroy'ed zone in the zone_array that we can reuse instead of initializing a new zone. */
+ for (int index = bitmap_first(zone_empty_bitmap, MAX_ZONES);
+ index >= 0 && index < (int)num_zones;
+ index = bitmap_next(zone_empty_bitmap, index)) {
+ z = &(zone_array[index]);
+
+ /*
+ * If the zone name and the element size are the same, we can just reuse the old zone struct.
+ * Otherwise hand out a new zone from the zone_array.
+ */
+ if (!strcmp(z->zone_name, name)) {
+ vm_size_t old_size = z->elem_size;
+#if KASAN_ZALLOC
+ old_size -= z->kasan_redzone * 2;
+#endif
+ if (old_size == size) {
+ /* Clear the empty bit for this zone, increment num_zones_in_use, and mark the zone as valid again. */
+ bitmap_clear(zone_empty_bitmap, index);
+ num_zones_in_use++;
+ z->zone_valid = TRUE;
+
+ /* All other state is already set up since the zone was previously in use. Return early. */
+ simple_unlock(&all_zones_lock);
+ return (z);
+ }
+ }
+ }
+
+ /* If we're here, it means we didn't find a zone above that we could simply reuse. Set up a new zone. */
+
+ /* Clear the empty bit for the new zone */
+ bitmap_clear(zone_empty_bitmap, num_zones);
+
+ z = &(zone_array[num_zones]);
+ z->index = num_zones;
+
+ num_zones++;
+ num_zones_in_use++;
+
+ /*
+ * Initialize the zone lock here before dropping the all_zones_lock. Otherwise we could race with
+ * zalloc_async() and try to grab the zone lock before it has been initialized, causing a panic.
+ */
+ lock_zone_init(z);
+
+ simple_unlock(&all_zones_lock);
+
+#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. kalloc
+ * and fakestack handles its own KASan state, so ignore those zones. */
+ /* XXX: remove this when zinit_with_options() is a thing */
+ const char *kalloc_name = "kalloc.";
+ const char *fakestack_name = "fakestack.";
+ if (strncmp(name, kalloc_name, strlen(kalloc_name)) == 0) {
+ z->kasan_redzone = 0;
+ } else if (strncmp(name, fakestack_name, strlen(fakestack_name)) == 0) {
+ z->kasan_redzone = 0;
+ } else {
+ if ((size % PAGE_SIZE) != 0) {
+ z->kasan_redzone = KASAN_GUARD_SIZE;
+ } else {
+ z->kasan_redzone = PAGE_SIZE;
+ }
+ max = (max / size) * (size + z->kasan_redzone * 2);
+ size += z->kasan_redzone * 2;
+ }
+#endif
+
+ max = round_page(max);
+
+ vm_size_t best_alloc = PAGE_SIZE;
+
+ if ((size % PAGE_SIZE) == 0) {
+ /* zero fragmentation by definition */
+ best_alloc = size;
+ } else {
+ 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->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;
+ z->kasan_quarantine = TRUE;
+ z->zone_valid = TRUE;
+
+#if CONFIG_ZLEAKS
+ z->zleak_capture = 0;
+ z->zleak_on = FALSE;
+#endif /* CONFIG_ZLEAKS */
+
+ /*
+ * If the VM is ready to handle kmem_alloc requests, copy the zone name passed in.
+ *
+ * Else simply maintain a pointer to the name string. The only zones we'll actually have
+ * to do this for would be the VM-related zones that are created very early on before any
+ * kexts can be loaded (unloaded). So we should be fine with just a pointer in this case.
+ */
+ if (kmem_alloc_ready) {
+ size_t len = MIN(strlen(name)+1, MACH_ZONE_NAME_MAX_LEN);
+
+ if (zone_names_start == 0 || ((zone_names_next - zone_names_start) + len) > PAGE_SIZE) {
+ printf("zalloc: allocating memory for zone names buffer\n");
+ kern_return_t retval = kmem_alloc_kobject(kernel_map, &zone_names_start,
+ PAGE_SIZE, VM_KERN_MEMORY_OSFMK);
+ if (retval != KERN_SUCCESS) {
+ panic("zalloc: zone_names memory allocation failed");
+ }
+ bzero((char *)zone_names_start, PAGE_SIZE);
+ zone_names_next = zone_names_start;
+ }
+
+ strlcpy((char *)zone_names_next, name, len);
+ z->zone_name = (char *)zone_names_next;
+ zone_names_next += len;
+ } else {
+ z->zone_name = name;
+ }
+
+ /*
+ * Check for and set up zone leak detection if requested via boot-args. We recognized two
+ * boot-args:
+ *
+ * zlog=<zone_to_log>
+ * zrecs=<num_records_in_log>
+ *
+ * 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.
+ */
+
+ if (num_zones_logged < max_num_zones_to_log) {
+
+ 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... */
+
+ while (i <= max_num_zones_to_log) {
+
+ snprintf(zlog_name, MAX_ZONE_NAME, "zlog%d", i);
+
+ if (PE_parse_boot_argn(zlog_name, zone_name_to_log, sizeof(zone_name_to_log)) == TRUE) {
+ if (track_this_zone(z->zone_name, zone_name_to_log)) {
+ if (z->zone_valid) {
+ z->zone_logging = TRUE;
+ zone_logging_enabled = TRUE;
+ num_zones_logged++;
+ break;
+ }
+ }
+ }
+ i++;
+ }
+
+ 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 (track_this_zone(z->zone_name, zone_name_to_log)) {
+ if (z->zone_valid) {
+ z->zone_logging = TRUE;
+ zone_logging_enabled = TRUE;
+ num_zones_logged++;
+ }
+ }
+ }
+ }
+
+ 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.
+ */
+
+ log_records = MIN(ZRECORDS_MAX, log_records);
+ log_records_init = TRUE;
+ } else {
+ log_records = ZRECORDS_DEFAULT;
+ log_records_init = TRUE;
+ }
+ }
+
+ /*
+ * 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.
+ */
+ 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++) {
+
+ curr_zone = &(zone_array[zone_idx]);
+
+ if (!curr_zone->zone_valid) {
+ continue;
+ }
+
+ /*
+ * 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) {
+
+ curr_zone->zlog_btlog = btlog_create(log_records, MAX_ZTRACE_DEPTH, (corruption_debug_flag == FALSE) /* caller_will_remove_entries_for_element? */);
+
+ if (curr_zone->zlog_btlog) {
+
+ 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 CONFIG_GZALLOC
+ gzalloc_zone_init(z);
+#endif
+
+ return(z);
+}
+unsigned zone_replenish_loops, zone_replenish_wakeups, zone_replenish_wakeups_initiated, zone_replenish_throttle_count;
+
+static void zone_replenish_thread(zone_t);
+
+/* 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)
+{
+ vm_size_t free_size;
+ current_thread()->options |= TH_OPT_VMPRIV;
+
+ for (;;) {
+ lock_zone(z);
+ assert(z->zone_valid);
+ 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;
+
+ /* Trigger jetsams via the vm_pageout_garbage_collect thread if we're running out of zone memory */
+ if (is_zone_map_nearing_exhaustion()) {
+ thread_wakeup((event_t) &vm_pageout_garbage_collect);
+ }
+
+ 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);
+ }
+ }
+
+ lock_zone(z);
+ assert(z->zone_valid);
+ zone_replenish_loops++;
+ }
+
+ z->zone_replenishing = FALSE;
+ /* Signal any potential throttled consumers, terminating
+ * their timer-bounded waits.
+ */
+ thread_wakeup(z);
+
+ assert_wait(&z->zone_replenish_thread, THREAD_UNINT);
+ unlock_zone(z);
+ thread_block(THREAD_CONTINUE_NULL);
+ zone_replenish_wakeups++;
+ }
+}
+
+void
+zone_prio_refill_configure(zone_t z, vm_size_t low_water_mark) {
+ z->prio_refill_watermark = low_water_mark;
+
+ 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 (tres != KERN_SUCCESS) {
+ panic("zone_prio_refill_configure, thread create: 0x%x", tres);
+ }
+
+ thread_deallocate(z->zone_replenish_thread);
+}
+
+void
+zdestroy(zone_t z)
+{
+ unsigned int zindex;
+
+ assert(z != NULL);
+
+ lock_zone(z);
+ assert(z->zone_valid);
+
+ /* Assert that the zone does not have any allocations in flight */
+ assert(z->doing_alloc_without_vm_priv == FALSE);
+ assert(z->doing_alloc_with_vm_priv == FALSE);
+ assert(z->async_pending == FALSE);
+ assert(z->waiting == FALSE);
+ assert(z->async_prio_refill == FALSE);
+
+#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->zone_valid = FALSE;
+#endif
+ unlock_zone(z);
+
+ /* Dump all the free elements */
+ drop_free_elements(z);
+
+#if CONFIG_GZALLOC
+ /* If the zone is gzalloc managed dump all the elements in the free cache */
+ gzalloc_empty_free_cache(z);
+#endif
+
+ lock_zone(z);
+
+#if !KASAN_ZALLOC
+ /* Assert that all counts are zero */
+ assert(z->count == 0);
+ assert(z->countfree == 0);
+ assert(z->cur_size == 0);
+ assert(z->page_count == 0);
+ assert(z->count_all_free_pages == 0);
+
+ /* Assert that all queues except the foreign queue are empty. The zone allocator doesn't know how to free up foreign memory. */
+ assert(queue_empty(&z->pages.all_used));
+ assert(queue_empty(&z->pages.intermediate));
+ assert(queue_empty(&z->pages.all_free));
+#endif
+
+ zindex = z->index;
+
+ unlock_zone(z);
+
+ simple_lock(&all_zones_lock);
+
+ assert(!bitmap_test(zone_empty_bitmap, zindex));
+ /* Mark the zone as empty in the bitmap */
+ bitmap_set(zone_empty_bitmap, zindex);
+ num_zones_in_use--;
+ assert(num_zones_in_use > 0);
+
+ simple_unlock(&all_zones_lock);
+}
+
+/* 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;
+
+ /* The first page is the real metadata for this allocation chunk. We mark the others as fake metadata */
+ size -= PAGE_SIZE;
+ newmem += PAGE_SIZE;
+
+ 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;
+ }
+ return;
+}
+
+
+/*
+ * 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;
+
+ assert(element_count <= ZONE_CHUNK_MAXELEMENTS);
+ 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 || __improbable(zone->tags) ||
+#endif /* DEBUG || DEVELOPMENT */
+ random_bool_gen(entropy_buffer, index, MAX_ENTROPY_PER_ZCRAM)) {
+ element_addr = newmem + first_element_offset;
+ first_element_offset += elem_size;
+ } else {
+ element_addr = newmem + last_element_offset;
+ last_element_offset -= elem_size;
+ }
+ if (element_addr != (vm_offset_t)zone) {
+ zone->count++; /* compensate for free_to_zone */
+ free_to_zone(zone, element_addr, FALSE);
+ }
+ zone->cur_size += elem_size;
+ }
+}
+
+/*
+ * Cram the given memory into the specified zone. Update the zone page count accordingly.
+ */
+void
+zcram(
+ zone_t zone,
+ vm_offset_t newmem,
+ vm_size_t size)
+{
+ 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;
+
+ KDBG(MACHDBG_CODE(DBG_MACH_ZALLOC, ZALLOC_ZCRAM) | DBG_FUNC_START, zone->index, size);
+
+ 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;
+ assert((size / PAGE_SIZE) <= ZONE_CHUNK_MAXPAGES);
+ chunk_metadata->page_count = (unsigned)(size / PAGE_SIZE);
+
+ zcram_metadata_init(newmem, size, chunk_metadata);
+
+#if VM_MAX_TAG_ZONES
+ if (__improbable(zone->tags)) {
+ assert(from_zm);
+ ztMemoryAdd(zone, newmem, size);
+ }
+#endif /* VM_MAX_TAG_ZONES */
+
+ lock_zone(zone);
+ assert(zone->zone_valid);
+ enqueue_tail(&zone->pages.all_used, &(chunk_metadata->pages));
+
+ 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
+ */
+
+ 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);
+ }
+ } else {
+ element_count = (int)(size / elem_size);
+ random_free_to_zone(zone, newmem, 0, element_count, entropy_buffer);
+ }
+ unlock_zone(zone);
+
+ KDBG(MACHDBG_CODE(DBG_MACH_ZALLOC, ZALLOC_ZCRAM) | DBG_FUNC_END, zone->index);
+
+}
+
+/*
+ * Fill a zone with enough memory to contain at least nelem elements.
+ * 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 the next zone allocation size.
+ */
+int
+zfill(
+ zone_t zone,
+ int nelem)
+{
+ kern_return_t kr;
+ vm_offset_t memory;
+
+ vm_size_t alloc_size = zone->alloc_size;
+ vm_size_t elem_per_alloc = alloc_size / zone->elem_size;
+ vm_size_t nalloc = (nelem + elem_per_alloc - 1) / elem_per_alloc;
+
+ /* Don't mix-and-match zfill with foreign memory */
+ assert(!zone->allows_foreign);
+
+ /* Trigger jetsams via the vm_pageout_garbage_collect thread if we're running out of zone memory */
+ if (is_zone_map_nearing_exhaustion()) {
+ thread_wakeup((event_t) &vm_pageout_garbage_collect);
+ }
+
+ kr = kernel_memory_allocate(zone_map, &memory, nalloc * alloc_size, 0, KMA_KOBJECT, VM_KERN_MEMORY_ZONE);
+ if (kr != KERN_SUCCESS) {
+ printf("%s: kernel_memory_allocate() of %lu bytes failed\n",
+ __func__, (unsigned long)(nalloc * alloc_size));
+ return 0;
+ }
+
+ for (vm_size_t i = 0; i < nalloc; i++) {
+ zcram(zone, memory + i * alloc_size, alloc_size);
+ }
+
+ return (int)(nalloc * elem_per_alloc);
+}
+
+/*
+ * 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)
+{
+ char temp_buf[16];
+ unsigned int i;
+
+ if (!PE_parse_boot_argn("zalloc_debug", &zalloc_debug, sizeof(zalloc_debug)))
+ zalloc_debug = 0;
+
+ /* Set up zone element poisoning */
+ zp_init();
+
+ /* 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();
+ }
+ simple_lock_init(&bool_gen_lock, 0);
+
+ /* 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;
+ }
+
+#if DEBUG || DEVELOPMENT
+#if VM_MAX_TAG_ZONES
+ /* enable tags for zones that ask for */
+ if (PE_parse_boot_argn("-zt", temp_buf, sizeof(temp_buf))) {
+ zone_tagging_on = TRUE;
+ }
+#endif /* VM_MAX_TAG_ZONES */
+ /* disable element location randomization in a page */
+ if (PE_parse_boot_argn("-zl", temp_buf, sizeof(temp_buf))) {
+ leak_scan_debug_flag = TRUE;
+ }
+#endif
+
+ simple_lock_init(&all_zones_lock, 0);
+
+ num_zones_in_use = 0;
+ num_zones = 0;
+ /* Mark all zones as empty */
+ bitmap_full(zone_empty_bitmap, BITMAP_LEN(MAX_ZONES));
+ zone_names_next = zone_names_start = 0;
+
+#if DEBUG || DEVELOPMENT
+ simple_lock_init(&zone_test_lock, 0);
+#endif /* DEBUG || DEVELOPMENT */
+
+ thread_call_setup(&call_async_alloc, zalloc_async, NULL);
+
+ /* 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);
+
+ 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);
+}
+
+/*
+ * 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.
+ */
+unsigned int zone_map_jetsam_limit = ZONE_MAP_JETSAM_LIMIT_DEFAULT;
+
+/*
+ * Returns pid of the task with the largest number of VM map entries.
+ */
+extern pid_t find_largest_process_vm_map_entries(void);
+
+/*
+ * 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.
+ */
+boolean_t memorystatus_kill_on_zone_map_exhaustion(pid_t pid);
+
+void get_zone_map_size(uint64_t *current_size, uint64_t *capacity)
+{
+ *current_size = zone_map->size;
+ *capacity = vm_map_max(zone_map) - vm_map_min(zone_map);
+}
+
+void get_largest_zone_info(char *zone_name, size_t zone_name_len, uint64_t *zone_size)
+{
+ zone_t largest_zone = zone_find_largest();
+ strlcpy(zone_name, largest_zone->zone_name, zone_name_len);
+ *zone_size = largest_zone->cur_size;
+}
+
+boolean_t is_zone_map_nearing_exhaustion(void)
+{
+ uint64_t size = zone_map->size;
+ uint64_t capacity = vm_map_max(zone_map) - vm_map_min(zone_map);
+ if (size > ((capacity * zone_map_jetsam_limit) / 100)) {
+ return TRUE;
+ }
+ return FALSE;
+}
+
+extern zone_t vm_map_entry_zone;
+extern zone_t vm_object_zone;
+
+#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 map size %lld, capacity %lld [jetsam limit %d%%]\n", (uint64_t)zone_map->size,
+ (uint64_t)(vm_map_max(zone_map) - vm_map_min(zone_map)), zone_map_jetsam_limit);
+ printf("zone_map_exhaustion: Largest zone %s, size %lu\n", largest_zone->zone_name, (uintptr_t)largest_zone->cur_size);
+
+ /*
+ * 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) {
+ int vm_object_zone_count = vm_object_zone->count;
+ int vm_map_entry_zone_count = vm_map_entry_zone->count;
+ /* 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)largest_zone->cur_size);
+ }
+ }
+
+ /* 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]. Waking up memorystatus thread.\n", largest_zone->zone_name);
+ }
+ if (!memorystatus_kill_on_zone_map_exhaustion(pid)) {
+ printf("zone_map_exhaustion: Call to memorystatus failed, victim pid: %d\n", pid);
+ }
+}
+
+/* Global initialization of Zone Allocator.
+ * Runs after zone_bootstrap.
+ */
+void
+zone_init(
+ vm_size_t max_zonemap_size)
+{
+ kern_return_t retval;
+ vm_offset_t zone_min;
+ vm_offset_t zone_max;
+ vm_offset_t zone_metadata_space;
+ unsigned int zone_pages;
+ vm_map_kernel_flags_t vmk_flags;
+
+#if VM_MAX_TAG_ZONES
+ if (zone_tagging_on) ztInit(max_zonemap_size, &zone_locks_grp);
+#endif
+
+ vmk_flags = VM_MAP_KERNEL_FLAGS_NONE;
+ vmk_flags.vmkf_permanent = TRUE;
+ retval = kmem_suballoc(kernel_map, &zone_min, max_zonemap_size,
+ FALSE, VM_FLAGS_ANYWHERE, vmk_flags, VM_KERN_MEMORY_ZONE,
+ &zone_map);
+
+ 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;
+
+ 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;
+
+#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
+ */
+ 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);
+#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 */
+
+#if VM_MAX_TAG_ZONES
+ if (zone_tagging_on) vm_allocation_zones_init();
+#endif
+
+ int jetsam_limit_temp = 0;
+ if (PE_parse_boot_argn("zone_map_jetsam_limit", &jetsam_limit_temp, sizeof (jetsam_limit_temp)) &&
+ jetsam_limit_temp > 0 && jetsam_limit_temp <= 100)
+ zone_map_jetsam_limit = jetsam_limit_temp;
+}
+
+extern volatile SInt32 kfree_nop_count;
+
+#pragma mark -
+#pragma mark zalloc_canblock
+
+extern boolean_t early_boot_complete;
+
+/*
+ * zalloc returns an element from the specified zone.
+ */
+static void *
+zalloc_internal(
+ zone_t zone,
+ boolean_t canblock,
+ boolean_t nopagewait,
+ vm_size_t
+#if !VM_MAX_TAG_ZONES
+ __unused
+#endif
+ reqsize,
+ vm_tag_t tag)
+{
+ 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;
+ thread_t thr = current_thread();
+ boolean_t check_poison = FALSE;
+ boolean_t set_doing_alloc_with_vm_priv = FALSE;
+
+#if CONFIG_ZLEAKS
+ uint32_t zleak_tracedepth = 0; /* log this allocation if nonzero */
+#endif /* CONFIG_ZLEAKS */
+
+#if KASAN
+ /*
+ * KASan uses zalloc() for fakestack, which can be called anywhere. However,
+ * we make sure these calls can never block.
+ */
+ boolean_t irq_safe = FALSE;
+ const char *fakestack_name = "fakestack.";
+ if (strncmp(zone->zone_name, fakestack_name, strlen(fakestack_name)) == 0) {
+ irq_safe = TRUE;
+ }
+#elif MACH_ASSERT
+ /* In every other case, zalloc() from interrupt context is unsafe. */
+ const boolean_t irq_safe = FALSE;
+#endif
+
+ assert(zone != ZONE_NULL);
+ assert(irq_safe || ml_get_interrupts_enabled() || ml_is_quiescing() || debug_mode_active() || !early_boot_complete);
+
+#if CONFIG_GZALLOC
+ addr = gzalloc_alloc(zone, canblock);
+#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);
projects / apple / xnu.git / blobdiff