san/kasan_internal.h

   1 /*
   2  * Copyright (c) 2000-2014 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #ifndef _KASAN_INTERNAL_H_
  30 #define _KASAN_INTERNAL_H_
  31
  32 #include <stdbool.h>
  33 #include <mach/mach_vm.h>
  34 #include <kern/zalloc.h>
  35
  36 typedef uintptr_t uptr;
  37
  38 #define MiB(x) ((x) * 1024UL * 1024)
  39
  40 /*
  41  * KASAN features and config
  42  */
  43 #define KASAN_DEBUG   0
  44 #define FAKESTACK     1
  45 /* KASAN_KALLOC defined in kasan.h */
  46 /* KASAN_ZALLOC defined in kasan.h */
  47 #define FAKESTACK_QUARANTINE (1 && FAKESTACK)
  48
  49 #define QUARANTINE_ENTRIES 5000
  50 #define QUARANTINE_MAXSIZE MiB(10)
  51
  52 /*
  53  * The amount of physical memory stolen by KASan at boot to back the shadow memory
  54  * and page tables. Larger memory systems need to steal proportionally less.
  55  */
  56 #ifdef __arm64__
  57 /* Works out at about 25% of 512 MiB and 15% of 3GiB system */
  58 # define STOLEN_MEM_PERCENT  13UL
  59 # define STOLEN_MEM_BYTES    MiB(62)
  60 #else
  61 # define STOLEN_MEM_PERCENT  25UL
  62 # define STOLEN_MEM_BYTES    0
  63 #endif
  64
  65 /* boot-args */
  66 #define KASAN_ARGS_FAKESTACK       0x0010U
  67 #define KASAN_ARGS_REPORTIGNORED   0x0020U
  68 #define KASAN_ARGS_NODYCHECKS      0x0100U
  69 #define KASAN_ARGS_NOPOISON_HEAP   0x0200U
  70 #define KASAN_ARGS_NOPOISON_GLOBAL 0x0400U
  71
  72 #ifndef KASAN
  73 # error KASAN undefined
  74 #endif
  75
  76 #ifndef KASAN_SHIFT
  77 # error KASAN_SHIFT undefined
  78 #endif
  79
  80 #define ADDRESS_FOR_SHADOW(x) (((x) - KASAN_SHIFT) << 3)
  81 #define SHADOW_FOR_ADDRESS(x) (uint8_t *)(((x) >> 3) + KASAN_SHIFT)
  82
  83 #if KASAN_DEBUG
  84 # define NOINLINE __attribute__ ((noinline))
  85 #else
  86 # define NOINLINE
  87 #endif
  88 #define ALWAYS_INLINE inline __attribute__((always_inline))
  89
  90 #define CLANG_MIN_VERSION(x) (defined(__apple_build_version__) && (__apple_build_version__ >= (x)))
  91
  92 #define BIT(x) (1U << (x))
  93
  94 enum __attribute__((flag_enum)) kasan_access_types {
  95         TYPE_LOAD    = BIT(0),  /* regular memory load */
  96         TYPE_STORE   = BIT(1),  /* regular store */
  97         TYPE_MEMR    = BIT(2),  /* memory intrinsic (read) */
  98         TYPE_MEMW    = BIT(3),  /* memory intrinsic (write) */
  99         TYPE_STRR    = BIT(4),  /* string intrinsic (read) */
 100         TYPE_STRW    = BIT(5),  /* string intrinsic (write) */
 101         TYPE_KFREE   = BIT(6),  /* kfree() */
 102         TYPE_ZFREE   = BIT(7),  /* zfree() */
 103         TYPE_FSFREE  = BIT(8),  /* fakestack free */
 104
 105         TYPE_UAF           = BIT(12),
 106         TYPE_POISON_GLOBAL = BIT(13),
 107         TYPE_POISON_HEAP   = BIT(14),
 108         /* no TYPE_POISON_STACK, because the runtime does not control stack poisoning */
 109         TYPE_TEST          = BIT(15),
 110
 111         /* masks */
 112         TYPE_MEM     = TYPE_MEMR|TYPE_MEMW,            /* memory intrinsics */
 113         TYPE_STR     = TYPE_STRR|TYPE_STRW,            /* string intrinsics */
 114         TYPE_READ    = TYPE_LOAD|TYPE_MEMR|TYPE_STRR,  /* all reads */
 115         TYPE_WRITE   = TYPE_STORE|TYPE_MEMW|TYPE_STRW, /* all writes */
 116         TYPE_RW      = TYPE_READ|TYPE_WRITE,           /* reads and writes */
 117         TYPE_FREE    = TYPE_KFREE|TYPE_ZFREE|TYPE_FSFREE,
 118         TYPE_NORMAL  = TYPE_RW|TYPE_FREE,
 119         TYPE_DYNAMIC = TYPE_NORMAL|TYPE_UAF,
 120         TYPE_POISON  = TYPE_POISON_GLOBAL|TYPE_POISON_HEAP,
 121         TYPE_ALL     = ~0U,
 122 };
 123
 124 enum kasan_violation_types {
 125         REASON_POISONED =       0, /* read or write of poisoned data */
 126         REASON_BAD_METADATA =   1, /* incorrect kasan metadata */
 127         REASON_INVALID_SIZE =   2, /* free size did not match alloc size */
 128         REASON_MOD_AFTER_FREE = 3, /* object modified after free */
 129         REASON_MOD_OOB =        4, /* out of bounds modification of object */
 130 };
 131
 132 typedef enum kasan_access_types access_t;
 133 typedef enum kasan_violation_types violation_t;
 134
 135 bool kasan_range_poisoned(vm_offset_t base, vm_size_t size, vm_offset_t *first_invalid);
 136 void kasan_check_range(const void *x, size_t sz, access_t);
 137 void kasan_test(int testno, int fail);
 138 void kasan_handle_test(void);
 139 void kasan_free_internal(void **addrp, vm_size_t *sizep, int type, zone_t *, vm_size_t user_size, int locked, bool doquarantine);
 140 void kasan_poison(vm_offset_t base, vm_size_t size, vm_size_t leftrz, vm_size_t rightrz, uint8_t flags);
 141 void kasan_lock(boolean_t *b);
 142 void kasan_unlock(boolean_t b);
 143 bool kasan_lock_held(thread_t thread);
 144 void kasan_init_fakestack(void);
 145
 146 /* dynamic blacklist */
 147 void kasan_init_dybl(void);
 148 bool kasan_is_blacklisted(access_t);
 149 void kasan_dybl_load_kext(uintptr_t addr, const char *kextname);
 150 void kasan_dybl_unload_kext(uintptr_t addr);
 151
 152 /* arch-specific interface */
 153 void kasan_arch_init(void);
 154 bool kasan_is_shadow_mapped(uintptr_t shadowp);
 155
 156 extern vm_address_t kernel_vbase;
 157 extern vm_address_t kernel_vtop;
 158
 159 extern unsigned shadow_pages_used;
 160
 161 /* boot-arg configurable */
 162 extern int fakestack_enabled;
 163
 164 /* Describes the source location where a global is defined. */
 165 struct asan_global_source_location {
 166         const char *filename;
 167         int line_no;
 168         int column_no;
 169 };
 170
 171 /* Describes an instrumented global variable. */
 172 struct asan_global {
 173         uptr addr;
 174         uptr size;
 175         uptr size_with_redzone;
 176         const char *name;
 177         const char *module;
 178         uptr has_dynamic_init;
 179         struct asan_global_source_location *location;
 180 #if CLANG_MIN_VERSION(8020000)
 181         uptr odr_indicator;
 182 #endif
 183 };
 184
 185 #if defined(__x86_64__)
 186 # define _JBLEN ((9 * 2) + 3 + 16)
 187 #elif defined(__arm64__)
 188 # define _JBLEN ((14 + 8 + 2) * 2)
 189 #else
 190 # error "Unknown arch"
 191 #endif
 192
 193 typedef int jmp_buf[_JBLEN];
 194 void _longjmp(jmp_buf env, int val);
 195 int _setjmp(jmp_buf env);
 196
 197 #endif /* _KASAN_INTERNAL_H_ */