asan_mapping.h revision 1.12
1 //===-- asan_mapping.h ------------------------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file is a part of AddressSanitizer, an address sanity checker. 10 // 11 // Defines ASan memory mapping. 12 //===----------------------------------------------------------------------===// 13 #ifndef ASAN_MAPPING_H 14 #define ASAN_MAPPING_H 15 16 #include "sanitizer_common/sanitizer_platform.h" 17 18 // The full explanation of the memory mapping could be found here: 19 // https://github.com/google/sanitizers/wiki/AddressSanitizerAlgorithm 20 // 21 // Typical shadow mapping on Linux/x86_64 with SHADOW_OFFSET == 0x00007fff8000: 22 // || `[0x10007fff8000, 0x7fffffffffff]` || HighMem || 23 // || `[0x02008fff7000, 0x10007fff7fff]` || HighShadow || 24 // || `[0x00008fff7000, 0x02008fff6fff]` || ShadowGap || 25 // || `[0x00007fff8000, 0x00008fff6fff]` || LowShadow || 26 // || `[0x000000000000, 0x00007fff7fff]` || LowMem || 27 // 28 // When SHADOW_OFFSET is zero (-pie): 29 // || `[0x100000000000, 0x7fffffffffff]` || HighMem || 30 // || `[0x020000000000, 0x0fffffffffff]` || HighShadow || 31 // || `[0x000000040000, 0x01ffffffffff]` || ShadowGap || 32 // 33 // Special case when something is already mapped between 34 // 0x003000000000 and 0x005000000000 (e.g. when prelink is installed): 35 // || `[0x10007fff8000, 0x7fffffffffff]` || HighMem || 36 // || `[0x02008fff7000, 0x10007fff7fff]` || HighShadow || 37 // || `[0x005000000000, 0x02008fff6fff]` || ShadowGap3 || 38 // || `[0x003000000000, 0x004fffffffff]` || MidMem || 39 // || `[0x000a7fff8000, 0x002fffffffff]` || ShadowGap2 || 40 // || `[0x00067fff8000, 0x000a7fff7fff]` || MidShadow || 41 // || `[0x00008fff7000, 0x00067fff7fff]` || ShadowGap || 42 // || `[0x00007fff8000, 0x00008fff6fff]` || LowShadow || 43 // || `[0x000000000000, 0x00007fff7fff]` || LowMem || 44 // 45 // Default Linux/i386 mapping on x86_64 machine: 46 // || `[0x40000000, 0xffffffff]` || HighMem || 47 // || `[0x28000000, 0x3fffffff]` || HighShadow || 48 // || `[0x24000000, 0x27ffffff]` || ShadowGap || 49 // || `[0x20000000, 0x23ffffff]` || LowShadow || 50 // || `[0x00000000, 0x1fffffff]` || LowMem || 51 // 52 // Default Linux/i386 mapping on i386 machine 53 // (addresses starting with 0xc0000000 are reserved 54 // for kernel and thus not sanitized): 55 // || `[0x38000000, 0xbfffffff]` || HighMem || 56 // || `[0x27000000, 0x37ffffff]` || HighShadow || 57 // || `[0x24000000, 0x26ffffff]` || ShadowGap || 58 // || `[0x20000000, 0x23ffffff]` || LowShadow || 59 // || `[0x00000000, 0x1fffffff]` || LowMem || 60 // 61 // Default Linux/MIPS32 mapping: 62 // || `[0x2aaa0000, 0xffffffff]` || HighMem || 63 // || `[0x0fff4000, 0x2aa9ffff]` || HighShadow || 64 // || `[0x0bff4000, 0x0fff3fff]` || ShadowGap || 65 // || `[0x0aaa0000, 0x0bff3fff]` || LowShadow || 66 // || `[0x00000000, 0x0aa9ffff]` || LowMem || 67 // 68 // Default Linux/MIPS64 mapping: 69 // || `[0x4000000000, 0xffffffffff]` || HighMem || 70 // || `[0x2800000000, 0x3fffffffff]` || HighShadow || 71 // || `[0x2400000000, 0x27ffffffff]` || ShadowGap || 72 // || `[0x2000000000, 0x23ffffffff]` || LowShadow || 73 // || `[0x0000000000, 0x1fffffffff]` || LowMem || 74 // 75 // Default Linux/RISCV64 Sv39 mapping: 76 // || `[0x1555550000, 0x3fffffffff]` || HighMem || 77 // || `[0x0fffffa000, 0x1555555fff]` || HighShadow || 78 // || `[0x0effffa000, 0x0fffff9fff]` || ShadowGap || 79 // || `[0x0d55550000, 0x0effff9fff]` || LowShadow || 80 // || `[0x0000000000, 0x0d5554ffff]` || LowMem || 81 // 82 // Default Linux/AArch64 (39-bit VMA) mapping: 83 // || `[0x2000000000, 0x7fffffffff]` || highmem || 84 // || `[0x1400000000, 0x1fffffffff]` || highshadow || 85 // || `[0x1200000000, 0x13ffffffff]` || shadowgap || 86 // || `[0x1000000000, 0x11ffffffff]` || lowshadow || 87 // || `[0x0000000000, 0x0fffffffff]` || lowmem || 88 // 89 // Default Linux/AArch64 (42-bit VMA) mapping: 90 // || `[0x10000000000, 0x3ffffffffff]` || highmem || 91 // || `[0x0a000000000, 0x0ffffffffff]` || highshadow || 92 // || `[0x09000000000, 0x09fffffffff]` || shadowgap || 93 // || `[0x08000000000, 0x08fffffffff]` || lowshadow || 94 // || `[0x00000000000, 0x07fffffffff]` || lowmem || 95 // 96 // Default Linux/S390 mapping: 97 // || `[0x30000000, 0x7fffffff]` || HighMem || 98 // || `[0x26000000, 0x2fffffff]` || HighShadow || 99 // || `[0x24000000, 0x25ffffff]` || ShadowGap || 100 // || `[0x20000000, 0x23ffffff]` || LowShadow || 101 // || `[0x00000000, 0x1fffffff]` || LowMem || 102 // 103 // Default Linux/SystemZ mapping: 104 // || `[0x14000000000000, 0x1fffffffffffff]` || HighMem || 105 // || `[0x12800000000000, 0x13ffffffffffff]` || HighShadow || 106 // || `[0x12000000000000, 0x127fffffffffff]` || ShadowGap || 107 // || `[0x10000000000000, 0x11ffffffffffff]` || LowShadow || 108 // || `[0x00000000000000, 0x0fffffffffffff]` || LowMem || 109 // 110 // Default Linux/SPARC64 (52-bit VMA) mapping: 111 // || `[0x8000000000000, 0xfffffffffffff]` || HighMem || 112 // || `[0x1080000000000, 0x207ffffffffff]` || HighShadow || 113 // || `[0x0090000000000, 0x107ffffffffff]` || ShadowGap || 114 // || `[0x0080000000000, 0x008ffffffffff]` || LowShadow || 115 // || `[0x0000000000000, 0x007ffffffffff]` || LowMem || 116 // 117 // Default Linux/LoongArch64 (47-bit VMA) mapping: 118 // || `[0x500000000000, 0x7fffffffffff]` || HighMem || 119 // || `[0x4a0000000000, 0x4fffffffffff]` || HighShadow || 120 // || `[0x480000000000, 0x49ffffffffff]` || ShadowGap || 121 // || `[0x400000000000, 0x47ffffffffff]` || LowShadow || 122 // || `[0x000000000000, 0x3fffffffffff]` || LowMem || 123 // 124 // Shadow mapping on FreeBSD/x86-64 with SHADOW_OFFSET == 0x400000000000: 125 // || `[0x500000000000, 0x7fffffffffff]` || HighMem || 126 // || `[0x4a0000000000, 0x4fffffffffff]` || HighShadow || 127 // || `[0x480000000000, 0x49ffffffffff]` || ShadowGap || 128 // || `[0x400000000000, 0x47ffffffffff]` || LowShadow || 129 // || `[0x000000000000, 0x3fffffffffff]` || LowMem || 130 // 131 // Shadow mapping on FreeBSD/i386 with SHADOW_OFFSET == 0x40000000: 132 // || `[0x60000000, 0xffffffff]` || HighMem || 133 // || `[0x4c000000, 0x5fffffff]` || HighShadow || 134 // || `[0x48000000, 0x4bffffff]` || ShadowGap || 135 // || `[0x40000000, 0x47ffffff]` || LowShadow || 136 // || `[0x00000000, 0x3fffffff]` || LowMem || 137 // 138 // Shadow mapping on NetBSD/x86-64 with SHADOW_OFFSET == 0x400000000000: 139 // || `[0x4feffffffe01, 0x7f7ffffff000]` || HighMem || 140 // || `[0x49fdffffffc0, 0x4feffffffe00]` || HighShadow || 141 // || `[0x480000000000, 0x49fdffffffbf]` || ShadowGap || 142 // || `[0x400000000000, 0x47ffffffffff]` || LowShadow || 143 // || `[0x000000000000, 0x3fffffffffff]` || LowMem || 144 // 145 // Shadow mapping on NetBSD/i386 with SHADOW_OFFSET == 0x40000000: 146 // || `[0x60000000, 0xfffff000]` || HighMem || 147 // || `[0x4c000000, 0x5fffffff]` || HighShadow || 148 // || `[0x48000000, 0x4bffffff]` || ShadowGap || 149 // || `[0x40000000, 0x47ffffff]` || LowShadow || 150 // || `[0x00000000, 0x3fffffff]` || LowMem || 151 // 152 // Default Windows/i386 mapping: 153 // (the exact location of HighShadow/HighMem may vary depending 154 // on WoW64, /LARGEADDRESSAWARE, etc). 155 // || `[0x50000000, 0xffffffff]` || HighMem || 156 // || `[0x3a000000, 0x4fffffff]` || HighShadow || 157 // || `[0x36000000, 0x39ffffff]` || ShadowGap || 158 // || `[0x30000000, 0x35ffffff]` || LowShadow || 159 // || `[0x00000000, 0x2fffffff]` || LowMem || 160 161 #define ASAN_SHADOW_SCALE 3 162 163 #if SANITIZER_FUCHSIA 164 # define ASAN_SHADOW_OFFSET_CONST (0) 165 #elif SANITIZER_WORDSIZE == 32 166 # if SANITIZER_ANDROID 167 # define ASAN_SHADOW_OFFSET_DYNAMIC 168 # elif defined(__mips__) 169 # define ASAN_SHADOW_OFFSET_CONST 0x0aaa0000 170 # elif SANITIZER_FREEBSD 171 # define ASAN_SHADOW_OFFSET_CONST 0x40000000 172 # elif SANITIZER_NETBSD 173 # define ASAN_SHADOW_OFFSET_CONST 0x40000000 174 # elif SANITIZER_WINDOWS 175 # define ASAN_SHADOW_OFFSET_CONST 0x30000000 176 # elif SANITIZER_IOS 177 # define ASAN_SHADOW_OFFSET_DYNAMIC 178 # else 179 # define ASAN_SHADOW_OFFSET_CONST 0x20000000 180 # endif 181 #else 182 # if SANITIZER_IOS 183 # define ASAN_SHADOW_OFFSET_DYNAMIC 184 # elif SANITIZER_APPLE && defined(__aarch64__) 185 # define ASAN_SHADOW_OFFSET_DYNAMIC 186 # elif SANITIZER_FREEBSD && defined(__aarch64__) 187 # define ASAN_SHADOW_OFFSET_CONST 0x0000800000000000 188 # elif SANITIZER_RISCV64 189 # define ASAN_SHADOW_OFFSET_CONST 0x0000000d55550000 190 # elif defined(__aarch64__) 191 # define ASAN_SHADOW_OFFSET_CONST 0x0000001000000000 192 # elif defined(__powerpc64__) 193 # define ASAN_SHADOW_OFFSET_CONST 0x0000020000000000 194 # elif defined(__s390x__) 195 # define ASAN_SHADOW_OFFSET_CONST 0x0010000000000000 196 # elif SANITIZER_FREEBSD 197 # define ASAN_SHADOW_OFFSET_CONST 0x0000400000000000 198 # elif SANITIZER_NETBSD 199 # define ASAN_SHADOW_OFFSET_CONST 0x0000400000000000 200 # elif SANITIZER_APPLE 201 # define ASAN_SHADOW_OFFSET_CONST 0x0000100000000000 202 # elif defined(__mips64) 203 # define ASAN_SHADOW_OFFSET_CONST 0x0000002000000000 204 # elif defined(__sparc__) 205 # define ASAN_SHADOW_OFFSET_CONST 0x0000080000000000 206 # elif SANITIZER_LOONGARCH64 207 # define ASAN_SHADOW_OFFSET_CONST 0x0000400000000000 208 # elif SANITIZER_WINDOWS64 209 # define ASAN_SHADOW_OFFSET_DYNAMIC 210 # else 211 # if ASAN_SHADOW_SCALE != 3 212 # error "Value below is based on shadow scale = 3." 213 # error "Original formula was: 0x7FFFFFFF & (~0xFFFULL << SHADOW_SCALE)." 214 # endif 215 # define ASAN_SHADOW_OFFSET_CONST 0x000000007fff8000 216 # endif 217 #endif 218 219 #if defined(__cplusplus) 220 # include "asan_internal.h" 221 222 static const u64 kDefaultShadowSentinel = ~(uptr)0; 223 224 # if defined(ASAN_SHADOW_OFFSET_CONST) 225 static const u64 kConstShadowOffset = ASAN_SHADOW_OFFSET_CONST; 226 # define ASAN_SHADOW_OFFSET kConstShadowOffset 227 # elif defined(ASAN_SHADOW_OFFSET_DYNAMIC) 228 # define ASAN_SHADOW_OFFSET __asan_shadow_memory_dynamic_address 229 # else 230 # error "ASAN_SHADOW_OFFSET can't be determined." 231 # endif 232 233 # if SANITIZER_ANDROID && defined(__arm__) 234 # define ASAN_PREMAP_SHADOW 1 235 # else 236 # define ASAN_PREMAP_SHADOW 0 237 # endif 238 239 # define ASAN_SHADOW_GRANULARITY (1ULL << ASAN_SHADOW_SCALE) 240 241 # define DO_ASAN_MAPPING_PROFILE 0 // Set to 1 to profile the functions below. 242 243 # if DO_ASAN_MAPPING_PROFILE 244 # define PROFILE_ASAN_MAPPING() AsanMappingProfile[__LINE__]++; 245 # else 246 # define PROFILE_ASAN_MAPPING() 247 # endif 248 249 // If 1, all shadow boundaries are constants. 250 // Don't set to 1 other than for testing. 251 # define ASAN_FIXED_MAPPING 0 252 253 namespace __asan { 254 255 extern uptr AsanMappingProfile[]; 256 257 # if ASAN_FIXED_MAPPING 258 // Fixed mapping for 64-bit Linux. Mostly used for performance comparison 259 // with non-fixed mapping. As of r175253 (Feb 2013) the performance 260 // difference between fixed and non-fixed mapping is below the noise level. 261 static uptr kHighMemEnd = 0x7fffffffffffULL; 262 static uptr kMidMemBeg = 0x3000000000ULL; 263 static uptr kMidMemEnd = 0x4fffffffffULL; 264 # else 265 extern uptr kHighMemEnd, kMidMemBeg, kMidMemEnd; // Initialized in __asan_init. 266 # endif 267 268 } // namespace __asan 269 270 # if defined(__sparc__) && SANITIZER_WORDSIZE == 64 271 # include "asan_mapping_sparc64.h" 272 # else 273 # define MEM_TO_SHADOW(mem) \ 274 (((mem) >> ASAN_SHADOW_SCALE) + (ASAN_SHADOW_OFFSET)) 275 # define SHADOW_TO_MEM(mem) \ 276 (((mem) - (ASAN_SHADOW_OFFSET)) << (ASAN_SHADOW_SCALE)) 277 278 # define kLowMemBeg 0 279 # define kLowMemEnd (ASAN_SHADOW_OFFSET ? ASAN_SHADOW_OFFSET - 1 : 0) 280 281 # define kLowShadowBeg ASAN_SHADOW_OFFSET 282 # define kLowShadowEnd MEM_TO_SHADOW(kLowMemEnd) 283 284 # define kHighMemBeg (MEM_TO_SHADOW(kHighMemEnd) + 1) 285 286 # define kHighShadowBeg MEM_TO_SHADOW(kHighMemBeg) 287 # define kHighShadowEnd MEM_TO_SHADOW(kHighMemEnd) 288 289 # define kMidShadowBeg MEM_TO_SHADOW(kMidMemBeg) 290 # define kMidShadowEnd MEM_TO_SHADOW(kMidMemEnd) 291 292 // With the zero shadow base we can not actually map pages starting from 0. 293 // This constant is somewhat arbitrary. 294 # define kZeroBaseShadowStart 0 295 # define kZeroBaseMaxShadowStart (1 << 18) 296 297 # define kShadowGapBeg \ 298 (kLowShadowEnd ? kLowShadowEnd + 1 : kZeroBaseShadowStart) 299 # define kShadowGapEnd ((kMidMemBeg ? kMidShadowBeg : kHighShadowBeg) - 1) 300 301 # define kShadowGap2Beg (kMidMemBeg ? kMidShadowEnd + 1 : 0) 302 # define kShadowGap2End (kMidMemBeg ? kMidMemBeg - 1 : 0) 303 304 # define kShadowGap3Beg (kMidMemBeg ? kMidMemEnd + 1 : 0) 305 # define kShadowGap3End (kMidMemBeg ? kHighShadowBeg - 1 : 0) 306 307 namespace __asan { 308 309 static inline bool AddrIsInLowMem(uptr a) { 310 PROFILE_ASAN_MAPPING(); 311 return a <= kLowMemEnd; 312 } 313 314 static inline bool AddrIsInLowShadow(uptr a) { 315 PROFILE_ASAN_MAPPING(); 316 return a >= kLowShadowBeg && a <= kLowShadowEnd; 317 } 318 319 static inline bool AddrIsInMidMem(uptr a) { 320 PROFILE_ASAN_MAPPING(); 321 return kMidMemBeg && a >= kMidMemBeg && a <= kMidMemEnd; 322 } 323 324 static inline bool AddrIsInMidShadow(uptr a) { 325 PROFILE_ASAN_MAPPING(); 326 return kMidMemBeg && a >= kMidShadowBeg && a <= kMidShadowEnd; 327 } 328 329 static inline bool AddrIsInHighMem(uptr a) { 330 PROFILE_ASAN_MAPPING(); 331 return kHighMemBeg && a >= kHighMemBeg && a <= kHighMemEnd; 332 } 333 334 static inline bool AddrIsInHighShadow(uptr a) { 335 PROFILE_ASAN_MAPPING(); 336 return kHighMemBeg && a >= kHighShadowBeg && a <= kHighShadowEnd; 337 } 338 339 static inline bool AddrIsInShadowGap(uptr a) { 340 PROFILE_ASAN_MAPPING(); 341 if (kMidMemBeg) { 342 if (a <= kShadowGapEnd) 343 return ASAN_SHADOW_OFFSET == 0 || a >= kShadowGapBeg; 344 return (a >= kShadowGap2Beg && a <= kShadowGap2End) || 345 (a >= kShadowGap3Beg && a <= kShadowGap3End); 346 } 347 // In zero-based shadow mode we treat addresses near zero as addresses 348 // in shadow gap as well. 349 if (ASAN_SHADOW_OFFSET == 0) 350 return a <= kShadowGapEnd; 351 return a >= kShadowGapBeg && a <= kShadowGapEnd; 352 } 353 354 } // namespace __asan 355 356 # endif 357 358 namespace __asan { 359 360 static inline uptr MemToShadowSize(uptr size) { 361 return size >> ASAN_SHADOW_SCALE; 362 } 363 364 static inline bool AddrIsInMem(uptr a) { 365 PROFILE_ASAN_MAPPING(); 366 return AddrIsInLowMem(a) || AddrIsInMidMem(a) || AddrIsInHighMem(a) || 367 (flags()->protect_shadow_gap == 0 && AddrIsInShadowGap(a)); 368 } 369 370 static inline uptr MemToShadow(uptr p) { 371 PROFILE_ASAN_MAPPING(); 372 CHECK(AddrIsInMem(p)); 373 return MEM_TO_SHADOW(p); 374 } 375 376 static inline bool AddrIsInShadow(uptr a) { 377 PROFILE_ASAN_MAPPING(); 378 return AddrIsInLowShadow(a) || AddrIsInMidShadow(a) || AddrIsInHighShadow(a); 379 } 380 381 static inline uptr ShadowToMem(uptr p) { 382 PROFILE_ASAN_MAPPING(); 383 CHECK(AddrIsInShadow(p)); 384 return SHADOW_TO_MEM(p); 385 } 386 387 static inline bool AddrIsAlignedByGranularity(uptr a) { 388 PROFILE_ASAN_MAPPING(); 389 return (a & (ASAN_SHADOW_GRANULARITY - 1)) == 0; 390 } 391 392 static inline bool AddressIsPoisoned(uptr a) { 393 PROFILE_ASAN_MAPPING(); 394 const uptr kAccessSize = 1; 395 u8 *shadow_address = (u8 *)MEM_TO_SHADOW(a); 396 s8 shadow_value = *shadow_address; 397 if (shadow_value) { 398 u8 last_accessed_byte = 399 (a & (ASAN_SHADOW_GRANULARITY - 1)) + kAccessSize - 1; 400 return (last_accessed_byte >= shadow_value); 401 } 402 return false; 403 } 404 405 // Must be after all calls to PROFILE_ASAN_MAPPING(). 406 static const uptr kAsanMappingProfileSize = __LINE__; 407 408 } // namespace __asan 409 410 #endif // __cplusplus 411 412 #endif // ASAN_MAPPING_H 413
Indexes created Mon Jul 06 00:25:43 UTC 2026