/*
- * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2020 Apple Computer, 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
* 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,
* 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.
*/
-#ifdef KERNEL_PRIVATE
+#ifdef KERNEL_PRIVATE
-#ifndef _KERN_KALLOC_H_
+#ifndef _KERN_KALLOC_H_
#define _KERN_KALLOC_H_
#include <mach/machine/vm_types.h>
-#include <sys/cdefs.h>
+#include <mach/boolean.h>
+#include <mach/vm_types.h>
+#include <kern/zalloc.h>
__BEGIN_DECLS
-extern void *kalloc(vm_size_t size);
+#if XNU_KERNEL_PRIVATE
+
+/*!
+ * @typedef kalloc_heap_t
+ *
+ * @abstract
+ * A kalloc heap view represents a sub-accounting context
+ * for a given kalloc heap.
+ */
+typedef struct kalloc_heap {
+ struct kheap_zones *kh_zones;
+ zone_stats_t kh_stats;
+ const char *kh_name;
+ struct kalloc_heap *kh_next;
+ zone_kheap_id_t kh_heap_id;
+} *kalloc_heap_t;
-extern void *kalloc_noblock(vm_size_t size);
+/*!
+ * @macro KALLOC_HEAP_DECLARE
+ *
+ * @abstract
+ * (optionally) declare a kalloc heap view in a header.
+ *
+ * @discussion
+ * Unlike kernel zones, new full blown heaps cannot be instantiated.
+ * However new accounting views of the base heaps can be made.
+ */
+#define KALLOC_HEAP_DECLARE(var) \
+ extern struct kalloc_heap var[1]
-extern void kfree(void *data,
- vm_size_t size);
+/**
+ * @const KHEAP_ANY
+ *
+ * @brief
+ * A value that represents either the default or kext heap for codepaths that
+ * need to allow @c kheap_free() to either one.
+ *
+ * @discussion
+ * When the memory provenance is not known, this value can be used to free
+ * memory indiscriminately.
+ *
+ * Note: code using this constant can likely be used as a gadget to free
+ * arbitrary memory and its use is strongly discouraged.
+ */
+#define KHEAP_ANY ((struct kalloc_heap *)NULL)
-__END_DECLS
+/**
+ * @const KHEAP_DATA_BUFFERS
+ *
+ * @brief
+ * The builtin heap for bags of pure bytes.
+ *
+ * @discussion
+ * This set of kalloc zones should contain pure bags of bytes with no pointers
+ * or length/offset fields.
+ *
+ * The zones forming the heap aren't sequestered from each other, however the
+ * entire heap lives in a different submap from any other kernel allocation.
+ *
+ * The main motivation behind this separation is due to the fact that a lot of
+ * these objects have been used by attackers to spray the heap to make it more
+ * predictable while exploiting use-after-frees or overflows.
+ *
+ * Common attributes that make these objects useful for spraying includes
+ * control of:
+ * - Data in allocation
+ * - Time of alloc and free (lifetime)
+ * - Size of allocation
+ */
+KALLOC_HEAP_DECLARE(KHEAP_DATA_BUFFERS);
+
+/**
+ * @const KHEAP_KEXT
+ *
+ * @brief
+ * The builtin heap for allocations made by kexts.
+ *
+ * @discussion
+ * This set of kalloc zones should contain allocations from kexts and the
+ * individual zones in this heap are sequestered.
+ */
+KALLOC_HEAP_DECLARE(KHEAP_KEXT);
+
+/**
+ * @const KHEAP_DEFAULT
+ *
+ * @brief
+ * The builtin default core kernel kalloc heap.
+ *
+ * @discussion
+ * This set of kalloc zones should contain other objects that don't have their
+ * own security mitigations. The individual zones are themselves sequestered.
+ */
+KALLOC_HEAP_DECLARE(KHEAP_DEFAULT);
+
+/**
+ * @const KHEAP_TEMP
+ *
+ * @brief
+ * A heap that represents allocations that are always done in "scope" of
+ * a thread.
+ *
+ * @discussion
+ * Allocations in this heap must be allocated and freed "in scope", which means:
+ * - the thread that did the allocation will be the one doing the free,
+ * - allocations will be freed by the time the thread returns to userspace.
+ *
+ * This is an alias on the @c KHEAP_DEFAULT heap with added checks.
+ */
+KALLOC_HEAP_DECLARE(KHEAP_TEMP);
+
+/*!
+ * @macro KALLOC_HEAP_DEFINE
+ *
+ * @abstract
+ * Defines a given kalloc heap view and what it points to.
+ *
+ * @discussion
+ * Kalloc heaps are views over one of the pre-defined builtin heaps
+ * (such as @c KHEAP_DATA_BUFFERS or @c KHEAP_DEFAULT). Instantiating
+ * a new one allows for accounting of allocations through this view.
+ *
+ * Kalloc heap views are initialized during the @c STARTUP_SUB_ZALLOC phase,
+ * as the last rank. If views on zones are created, these must have been
+ * created before this stage.
+ *
+ * @param var the name for the zone view.
+ * @param name a string describing the zone view.
+ * @param heap_id a @c KHEAP_ID_* constant.
+ */
+#define KALLOC_HEAP_DEFINE(var, name, heap_id) \
+ SECURITY_READ_ONLY_LATE(struct kalloc_heap) var[1] = { { \
+ .kh_name = name, \
+ .kh_heap_id = heap_id, \
+ } }; \
+ STARTUP_ARG(ZALLOC, STARTUP_RANK_LAST, kheap_startup_init, var)
+
+#define kalloc(size) \
+ kheap_alloc(KHEAP_DEFAULT, size, Z_WAITOK)
+
+#define kalloc_flags(size, flags) \
+ kheap_alloc(KHEAP_DEFAULT, size, flags)
+
+#define kalloc_tag(size, itag) \
+ kheap_alloc_tag(KHEAP_DEFAULT, size, Z_WAITOK, itag)
+
+#define kalloc_tag_bt(size, itag) \
+ kheap_alloc_tag_bt(KHEAP_DEFAULT, size, Z_WAITOK, itag)
+
+#define krealloc(elem, old_size, new_size, flags) \
+ kheap_realloc(KHEAP_DEFAULT, elem, old_size, new_size, flags)
+
+/*
+ * These versions allow specifying the kalloc heap to allocate memory
+ * from
+ */
+#define kheap_alloc(kalloc_heap, size, flags) \
+ ({ VM_ALLOC_SITE_STATIC(0, 0); \
+ kalloc_ext(kalloc_heap, size, flags, &site).addr; })
+
+#define kheap_alloc_tag(kalloc_heap, size, flags, itag) \
+ ({ VM_ALLOC_SITE_STATIC(0, (itag)); \
+ kalloc_ext(kalloc_heap, size, flags, &site).addr; })
+
+#define kheap_alloc_tag_bt(kalloc_heap, size, flags, itag) \
+ ({ VM_ALLOC_SITE_STATIC(VM_TAG_BT, (itag)); \
+ kalloc_ext(kalloc_heap, size, flags, &site).addr; })
+
+#define kheap_realloc(kalloc_heap, elem, old_size, new_size, flags) \
+ ({ VM_ALLOC_SITE_STATIC(0, 0); \
+ krealloc_ext(kalloc_heap, elem, old_size, new_size, flags, &site).addr; })
+
+extern void
+kfree(
+ void *data,
+ vm_size_t size);
+
+extern void
+kheap_free(
+ kalloc_heap_t heap,
+ void *data,
+ vm_size_t size);
+
+__abortlike
+extern void
+kheap_temp_leak_panic(thread_t self);
+
+#else /* XNU_KERNEL_PRIVATE */
+
+extern void *kalloc(vm_size_t size) __attribute__((alloc_size(1)));
+
+extern void kfree(void *data, vm_size_t size);
+
+#endif /* !XNU_KERNEL_PRIVATE */
+#pragma mark implementation details
+#if XNU_KERNEL_PRIVATE
+#pragma GCC visibility push(hidden)
+
+/* Used by kern_os_* and operator new */
+KALLOC_HEAP_DECLARE(KERN_OS_MALLOC);
+
+extern void kheap_startup_init(
+ kalloc_heap_t heap);
-#ifdef MACH_KERNEL_PRIVATE
-#include <kern/lock.h>
+/*
+ * This type is used so that kalloc_internal has good calling conventions
+ * for callers who want to cheaply both know the allocated address
+ * and the actual size of the allocation.
+ */
+struct kalloc_result {
+ void *addr;
+ vm_size_t size;
+};
+
+extern struct kalloc_result
+kalloc_ext(
+ kalloc_heap_t kheap,
+ vm_size_t size,
+ zalloc_flags_t flags,
+ vm_allocation_site_t *site);
+
+extern struct kalloc_result
+krealloc_ext(
+ kalloc_heap_t kheap,
+ void *addr,
+ vm_size_t old_size,
+ vm_size_t new_size,
+ zalloc_flags_t flags,
+ vm_allocation_site_t *site);
+
+extern struct kalloc_result
+kheap_realloc_addr(
+ kalloc_heap_t kheap,
+ void *addr,
+ vm_size_t new_size,
+ zalloc_flags_t flags,
+ vm_allocation_site_t *site);
+
+
+/* these versions update the size reference with the actual size allocated */
+
+static inline void *
+kallocp_ext(
+ kalloc_heap_t kheap,
+ vm_size_t *size,
+ zalloc_flags_t flags,
+ vm_allocation_site_t *site)
+{
+ struct kalloc_result kar = kalloc_ext(kheap, *size, flags, site);
+ *size = kar.size;
+ return kar.addr;
+}
+
+#define kallocp(sizep) \
+ ({ VM_ALLOC_SITE_STATIC(0, 0); \
+ kallocp_ext(KHEAP_DEFAULT, sizep, Z_WAITOK, &site); })
+
+#define kallocp_tag(sizep, itag) \
+ ({ VM_ALLOC_SITE_STATIC(0, (itag)); \
+ kallocp_ext(KHEAP_DEFAULT, sizep, Z_WAITOK, &site); })
+
+#define kallocp_tag_bt(sizep, itag) \
+ ({ VM_ALLOC_SITE_STATIC(VM_TAG_BT, (itag)); \
+ kallocp_ext(KHEAP_DEFAULT, sizep, Z_WAITOK, &site); })
-extern void kalloc_init(void);
+extern vm_size_t
+kalloc_size(
+ void *addr);
-extern void kalloc_fake_zone_init( int );
+extern void
+kheap_free_addr(
+ kalloc_heap_t heap,
+ void *addr);
-extern void kalloc_fake_zone_info(
- int *count,
- vm_size_t *cur_size,
- vm_size_t *max_size,
- vm_size_t *elem_size,
- vm_size_t *alloc_size,
- uint64_t *sum_size,
- int *collectable,
- int *exhaustable,
- int *caller_acct);
+extern vm_size_t
+kalloc_bucket_size(
+ vm_size_t size);
+
+/*
+ * These macros set "elem" to NULL on free.
+ *
+ * Note: all values passed to k*free() might be in the element to be freed,
+ * temporaries must be taken, and the resetting to be done prior to free.
+ */
+#define kfree(elem, size) ({ \
+ _Static_assert(sizeof(elem) == sizeof(void *), "elem isn't pointer sized"); \
+ __auto_type __kfree_eptr = &(elem); \
+ __auto_type __kfree_elem = *__kfree_eptr; \
+ __auto_type __kfree_size = (size); \
+ *__kfree_eptr = (__typeof__(__kfree_elem))NULL; \
+ (kfree)((void *)__kfree_elem, __kfree_size); \
+})
+
+#define kheap_free(heap, elem, size) ({ \
+ _Static_assert(sizeof(elem) == sizeof(void *), "elem isn't pointer sized"); \
+ __auto_type __kfree_heap = (heap); \
+ __auto_type __kfree_eptr = &(elem); \
+ __auto_type __kfree_elem = *__kfree_eptr; \
+ __auto_type __kfree_size = (size); \
+ *__kfree_eptr = (__typeof__(__kfree_elem))NULL; \
+ (kheap_free)(__kfree_heap, (void *)__kfree_elem, __kfree_size); \
+})
+
+#define kheap_free_addr(heap, elem) ({ \
+ _Static_assert(sizeof(elem) == sizeof(void *), "elem isn't pointer sized"); \
+ __auto_type __kfree_heap = (heap); \
+ __auto_type __kfree_eptr = &(elem); \
+ __auto_type __kfree_elem = *__kfree_eptr; \
+ *__kfree_eptr = (__typeof__(__kfree_elem))NULL; \
+ (kheap_free_addr)(__kfree_heap, (void *)__kfree_elem); \
+})
+
+extern zone_t
+kalloc_heap_zone_for_size(
+ kalloc_heap_t heap,
+ vm_size_t size);
extern vm_size_t kalloc_max_prerounded;
extern vm_size_t kalloc_large_total;
-#endif /* MACH_KERNEL_PRIVATE */
+extern void
+kern_os_kfree(
+ void *addr,
+ vm_size_t size);
+
+#pragma GCC visibility pop
+#endif /* XNU_KERNEL_PRIVATE */
+
+extern void
+kern_os_zfree(
+ zone_t zone,
+ void *addr,
+ vm_size_t size);
+
+__END_DECLS
-#endif /* _KERN_KALLOC_H_ */
+#endif /* _KERN_KALLOC_H_ */
-#endif /* KERNEL_PRIVATE */
+#endif /* KERNEL_PRIVATE */
projects / apple / xnu.git / blobdiff