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 with SHADOW_OFFSET == 0xd55550000; 76 // (the exact location of SHADOW_OFFSET may vary depending the dynamic probing 77 // by FindDynamicShadowStart). 78 // 79 // || `[0x1555550000, 0x3fffffffff]` || HighMem || 80 // || `[0x0fffffa000, 0x1555555fff]` || HighShadow || 81 // || `[0x0effffa000, 0x0fffff9fff]` || ShadowGap || 82 // || `[0x0d55550000, 0x0effff9fff]` || LowShadow || 83 // || `[0x0000000000, 0x0d5554ffff]` || LowMem || 84 // 85 // Default Linux/AArch64 (39-bit VMA) mapping: 86 // || `[0x2000000000, 0x7fffffffff]` || highmem || 87 // || `[0x1400000000, 0x1fffffffff]` || highshadow || 88 // || `[0x1200000000, 0x13ffffffff]` || shadowgap || 89 // || `[0x1000000000, 0x11ffffffff]` || lowshadow || 90 // || `[0x0000000000, 0x0fffffffff]` || lowmem || 91 // 92 // Default Linux/AArch64 (42-bit VMA) mapping: 93 // || `[0x10000000000, 0x3ffffffffff]` || highmem || 94 // || `[0x0a000000000, 0x0ffffffffff]` || highshadow || 95 // || `[0x09000000000, 0x09fffffffff]` || shadowgap || 96 // || `[0x08000000000, 0x08fffffffff]` || lowshadow || 97 // || `[0x00000000000, 0x07fffffffff]` || lowmem || 98 // 99 // Default Linux/S390 mapping: 100 // || `[0x30000000, 0x7fffffff]` || HighMem || 101 // || `[0x26000000, 0x2fffffff]` || HighShadow || 102 // || `[0x24000000, 0x25ffffff]` || ShadowGap || 103 // || `[0x20000000, 0x23ffffff]` || LowShadow || 104 // || `[0x00000000, 0x1fffffff]` || LowMem || 105 // 106 // Default Linux/SystemZ mapping: 107 // || `[0x14000000000000, 0x1fffffffffffff]` || HighMem || 108 // || `[0x12800000000000, 0x13ffffffffffff]` || HighShadow || 109 // || `[0x12000000000000, 0x127fffffffffff]` || ShadowGap || 110 // || `[0x10000000000000, 0x11ffffffffffff]` || LowShadow || 111 // || `[0x00000000000000, 0x0fffffffffffff]` || LowMem || 112 // 113 // Default Linux/SPARC64 (52-bit VMA) mapping: 114 // || `[0x8000000000000, 0xfffffffffffff]` || HighMem || 115 // || `[0x1080000000000, 0x207ffffffffff]` || HighShadow || 116 // || `[0x0090000000000, 0x107ffffffffff]` || ShadowGap || 117 // || `[0x0080000000000, 0x008ffffffffff]` || LowShadow || 118 // || `[0x0000000000000, 0x007ffffffffff]` || LowMem || 119 // 120 // Default Linux/LoongArch64 (47-bit VMA) mapping: 121 // || `[0x500000000000, 0x7fffffffffff]` || HighMem || 122 // || `[0x4a0000000000, 0x4fffffffffff]` || HighShadow || 123 // || `[0x480000000000, 0x49ffffffffff]` || ShadowGap || 124 // || `[0x400000000000, 0x47ffffffffff]` || LowShadow || 125 // || `[0x000000000000, 0x3fffffffffff]` || LowMem || 126 // 127 // Shadow mapping on FreeBSD/x86-64 with SHADOW_OFFSET == 0x400000000000: 128 // || `[0x500000000000, 0x7fffffffffff]` || HighMem || 129 // || `[0x4a0000000000, 0x4fffffffffff]` || HighShadow || 130 // || `[0x480000000000, 0x49ffffffffff]` || ShadowGap || 131 // || `[0x400000000000, 0x47ffffffffff]` || LowShadow || 132 // || `[0x000000000000, 0x3fffffffffff]` || LowMem || 133 // 134 // Shadow mapping on FreeBSD/i386 with SHADOW_OFFSET == 0x40000000: 135 // || `[0x60000000, 0xffffffff]` || HighMem || 136 // || `[0x4c000000, 0x5fffffff]` || HighShadow || 137 // || `[0x48000000, 0x4bffffff]` || ShadowGap || 138 // || `[0x40000000, 0x47ffffff]` || LowShadow || 139 // || `[0x00000000, 0x3fffffff]` || LowMem || 140 // 141 // Shadow mapping on NetBSD/x86-64 with SHADOW_OFFSET == 0x400000000000: 142 // || `[0x4feffffffe01, 0x7f7ffffff000]` || HighMem || 143 // || `[0x49fdffffffc0, 0x4feffffffe00]` || HighShadow || 144 // || `[0x480000000000, 0x49fdffffffbf]` || ShadowGap || 145 // || `[0x400000000000, 0x47ffffffffff]` || LowShadow || 146 // || `[0x000000000000, 0x3fffffffffff]` || LowMem || 147 // 148 // Shadow mapping on NetBSD/i386 with SHADOW_OFFSET == 0x40000000: 149 // || `[0x60000000, 0xfffff000]` || HighMem || 150 // || `[0x4c000000, 0x5fffffff]` || HighShadow || 151 // || `[0x48000000, 0x4bffffff]` || ShadowGap || 152 // || `[0x40000000, 0x47ffffff]` || LowShadow || 153 // || `[0x00000000, 0x3fffffff]` || LowMem || 154 // 155 // Default Windows/i386 mapping: 156 // (the exact location of HighShadow/HighMem may vary depending 157 // on WoW64, /LARGEADDRESSAWARE, etc). 158 // || `[0x50000000, 0xffffffff]` || HighMem || 159 // || `[0x3a000000, 0x4fffffff]` || HighShadow || 160 // || `[0x36000000, 0x39ffffff]` || ShadowGap || 161 // || `[0x30000000, 0x35ffffff]` || LowShadow || 162 // || `[0x00000000, 0x2fffffff]` || LowMem || 163 164 #define ASAN_SHADOW_SCALE 3 165 166 #if SANITIZER_FUCHSIA 167 # define ASAN_SHADOW_OFFSET_CONST (0) 168 #elif SANITIZER_WORDSIZE == 32 169 # if SANITIZER_ANDROID 170 # define ASAN_SHADOW_OFFSET_DYNAMIC 171 # elif defined(__mips__) 172 # define ASAN_SHADOW_OFFSET_CONST 0x0aaa0000 173 # elif SANITIZER_FREEBSD 174 # define ASAN_SHADOW_OFFSET_CONST 0x40000000 175 # elif SANITIZER_NETBSD 176 # define ASAN_SHADOW_OFFSET_CONST 0x40000000 177 # elif SANITIZER_WINDOWS 178 # define ASAN_SHADOW_OFFSET_CONST 0x30000000 179 # elif SANITIZER_IOS 180 # define ASAN_SHADOW_OFFSET_DYNAMIC 181 # else 182 # define ASAN_SHADOW_OFFSET_CONST 0x20000000 183 # endif 184 #else 185 # if SANITIZER_IOS 186 # define ASAN_SHADOW_OFFSET_DYNAMIC 187 # elif SANITIZER_APPLE && defined(__aarch64__) 188 # define ASAN_SHADOW_OFFSET_DYNAMIC 189 # elif SANITIZER_FREEBSD && defined(__aarch64__) 190 # define ASAN_SHADOW_OFFSET_CONST 0x0000800000000000 191 # elif SANITIZER_RISCV64 192 # define ASAN_SHADOW_OFFSET_DYNAMIC 193 # elif defined(__aarch64__) 194 # define ASAN_SHADOW_OFFSET_CONST 0x0000001000000000 195 # elif defined(__powerpc64__) 196 # define ASAN_SHADOW_OFFSET_CONST 0x0000100000000000 197 # elif defined(__s390x__) 198 # define ASAN_SHADOW_OFFSET_CONST 0x0010000000000000 199 # elif SANITIZER_FREEBSD 200 # define ASAN_SHADOW_OFFSET_CONST 0x0000400000000000 201 # elif SANITIZER_NETBSD 202 # define ASAN_SHADOW_OFFSET_CONST 0x0000400000000000 203 # elif SANITIZER_APPLE 204 # define ASAN_SHADOW_OFFSET_CONST 0x0000100000000000 205 # elif defined(__mips64) 206 # define ASAN_SHADOW_OFFSET_CONST 0x0000002000000000 207 # elif defined(__sparc__) 208 # define ASAN_SHADOW_OFFSET_CONST 0x0000080000000000 209 # elif SANITIZER_LOONGARCH64 210 # define ASAN_SHADOW_OFFSET_CONST 0x0000400000000000 211 # elif SANITIZER_WINDOWS64 212 # define ASAN_SHADOW_OFFSET_DYNAMIC 213 # else 214 # if ASAN_SHADOW_SCALE != 3 215 # error "Value below is based on shadow scale = 3." 216 # error "Original formula was: 0x7FFFFFFF & (~0xFFFULL << SHADOW_SCALE)." 217 # endif 218 # define ASAN_SHADOW_OFFSET_CONST 0x000000007fff8000 219 # endif 220 #endif 221 222 #if defined(__cplusplus) 223 # include "asan_internal.h" 224 225 static const u64 kDefaultShadowSentinel = ~(uptr)0; 226 227 # if defined(ASAN_SHADOW_OFFSET_CONST) 228 static const u64 kConstShadowOffset = ASAN_SHADOW_OFFSET_CONST; 229 # define ASAN_SHADOW_OFFSET kConstShadowOffset 230 # elif defined(ASAN_SHADOW_OFFSET_DYNAMIC) 231 # define ASAN_SHADOW_OFFSET __asan_shadow_memory_dynamic_address 232 # else 233 # error "ASAN_SHADOW_OFFSET can't be determined." 234 # endif 235 236 # if SANITIZER_ANDROID && defined(__arm__) 237 # define ASAN_PREMAP_SHADOW 1 238 # else 239 # define ASAN_PREMAP_SHADOW 0 240 # endif 241 242 # define ASAN_SHADOW_GRANULARITY (1ULL << ASAN_SHADOW_SCALE) 243 244 # define DO_ASAN_MAPPING_PROFILE 0 // Set to 1 to profile the functions below. 245 246 # if DO_ASAN_MAPPING_PROFILE 247 # define PROFILE_ASAN_MAPPING() AsanMappingProfile[__LINE__]++; 248 # else 249 # define PROFILE_ASAN_MAPPING() 250 # endif 251 252 // If 1, all shadow boundaries are constants. 253 // Don't set to 1 other than for testing. 254 # define ASAN_FIXED_MAPPING 0 255 256 namespace __asan { 257 258 extern uptr AsanMappingProfile[]; 259 260 # if ASAN_FIXED_MAPPING 261 // Fixed mapping for 64-bit Linux. Mostly used for performance comparison 262 // with non-fixed mapping. As of r175253 (Feb 2013) the performance 263 // difference between fixed and non-fixed mapping is below the noise level. 264 static uptr kHighMemEnd = 0x7fffffffffffULL; 265 static uptr kMidMemBeg = 0x3000000000ULL; 266 static uptr kMidMemEnd = 0x4fffffffffULL; 267 # else 268 extern uptr kHighMemEnd, kMidMemBeg, kMidMemEnd; // Initialized in __asan_init. 269 # endif 270 271 } // namespace __asan 272 273 # if defined(__sparc__) && SANITIZER_WORDSIZE == 64 274 # include "asan_mapping_sparc64.h" 275 # else 276 # define MEM_TO_SHADOW(mem) \ 277 (((mem) >> ASAN_SHADOW_SCALE) + (ASAN_SHADOW_OFFSET)) 278 # define SHADOW_TO_MEM(mem) \ 279 (((mem) - (ASAN_SHADOW_OFFSET)) << (ASAN_SHADOW_SCALE)) 280 281 # define kLowMemBeg 0 282 # define kLowMemEnd (ASAN_SHADOW_OFFSET ? ASAN_SHADOW_OFFSET - 1 : 0) 283 284 # define kLowShadowBeg ASAN_SHADOW_OFFSET 285 # define kLowShadowEnd MEM_TO_SHADOW(kLowMemEnd) 286 287 # define kHighMemBeg (MEM_TO_SHADOW(kHighMemEnd) + 1) 288 289 # define kHighShadowBeg MEM_TO_SHADOW(kHighMemBeg) 290 # define kHighShadowEnd MEM_TO_SHADOW(kHighMemEnd) 291 292 # define kMidShadowBeg MEM_TO_SHADOW(kMidMemBeg) 293 # define kMidShadowEnd MEM_TO_SHADOW(kMidMemEnd) 294 295 // With the zero shadow base we can not actually map pages starting from 0. 296 // This constant is somewhat arbitrary. 297 # define kZeroBaseShadowStart 0 298 # define kZeroBaseMaxShadowStart (1 << 18) 299 300 # define kShadowGapBeg \ 301 (kLowShadowEnd ? kLowShadowEnd + 1 : kZeroBaseShadowStart) 302 # define kShadowGapEnd ((kMidMemBeg ? kMidShadowBeg : kHighShadowBeg) - 1) 303 304 # define kShadowGap2Beg (kMidMemBeg ? kMidShadowEnd + 1 : 0) 305 # define kShadowGap2End (kMidMemBeg ? kMidMemBeg - 1 : 0) 306 307 # define kShadowGap3Beg (kMidMemBeg ? kMidMemEnd + 1 : 0) 308 # define kShadowGap3End (kMidMemBeg ? kHighShadowBeg - 1 : 0) 309 310 namespace __asan { 311 312 static inline bool AddrIsInLowMem(uptr a) { 313 PROFILE_ASAN_MAPPING(); 314 return a <= kLowMemEnd; 315 } 316 317 static inline bool AddrIsInLowShadow(uptr a) { 318 PROFILE_ASAN_MAPPING(); 319 return a >= kLowShadowBeg && a <= kLowShadowEnd; 320 } 321 322 static inline bool AddrIsInMidMem(uptr a) { 323 PROFILE_ASAN_MAPPING(); 324 return kMidMemBeg && a >= kMidMemBeg && a <= kMidMemEnd; 325 } 326 327 static inline bool AddrIsInMidShadow(uptr a) { 328 PROFILE_ASAN_MAPPING(); 329 return kMidMemBeg && a >= kMidShadowBeg && a <= kMidShadowEnd; 330 } 331 332 static inline bool AddrIsInHighMem(uptr a) { 333 PROFILE_ASAN_MAPPING(); 334 return kHighMemBeg && a >= kHighMemBeg && a <= kHighMemEnd; 335 } 336 337 static inline bool AddrIsInHighShadow(uptr a) { 338 PROFILE_ASAN_MAPPING(); 339 return kHighMemBeg && a >= kHighShadowBeg && a <= kHighShadowEnd; 340 } 341 342 static inline bool AddrIsInShadowGap(uptr a) { 343 PROFILE_ASAN_MAPPING(); 344 if (kMidMemBeg) { 345 if (a <= kShadowGapEnd) 346 return ASAN_SHADOW_OFFSET == 0 || a >= kShadowGapBeg; 347 return (a >= kShadowGap2Beg && a <= kShadowGap2End) || 348 (a >= kShadowGap3Beg && a <= kShadowGap3End); 349 } 350 // In zero-based shadow mode we treat addresses near zero as addresses 351 // in shadow gap as well. 352 if (ASAN_SHADOW_OFFSET == 0) 353 return a <= kShadowGapEnd; 354 return a >= kShadowGapBeg && a <= kShadowGapEnd; 355 } 356 357 } // namespace __asan 358 359 # endif 360 361 namespace __asan { 362 363 static inline uptr MemToShadowSize(uptr size) { 364 return size >> ASAN_SHADOW_SCALE; 365 } 366 367 static inline bool AddrIsInMem(uptr a) { 368 PROFILE_ASAN_MAPPING(); 369 return AddrIsInLowMem(a) || AddrIsInMidMem(a) || AddrIsInHighMem(a) || 370 (flags()->protect_shadow_gap == 0 && AddrIsInShadowGap(a)); 371 } 372 373 static inline uptr MemToShadow(uptr p) { 374 PROFILE_ASAN_MAPPING(); 375 CHECK(AddrIsInMem(p)); 376 return MEM_TO_SHADOW(p); 377 } 378 379 static inline bool AddrIsInShadow(uptr a) { 380 PROFILE_ASAN_MAPPING(); 381 return AddrIsInLowShadow(a) || AddrIsInMidShadow(a) || AddrIsInHighShadow(a); 382 } 383 384 static inline uptr ShadowToMem(uptr p) { 385 PROFILE_ASAN_MAPPING(); 386 CHECK(AddrIsInShadow(p)); 387 return SHADOW_TO_MEM(p); 388 } 389 390 static inline bool AddrIsAlignedByGranularity(uptr a) { 391 PROFILE_ASAN_MAPPING(); 392 return (a & (ASAN_SHADOW_GRANULARITY - 1)) == 0; 393 } 394 395 static inline bool AddressIsPoisoned(uptr a) { 396 PROFILE_ASAN_MAPPING(); 397 const uptr kAccessSize = 1; 398 u8 *shadow_address = (u8 *)MEM_TO_SHADOW(a); 399 s8 shadow_value = *shadow_address; 400 if (shadow_value) { 401 u8 last_accessed_byte = 402 (a & (ASAN_SHADOW_GRANULARITY - 1)) + kAccessSize - 1; 403 return (last_accessed_byte >= shadow_value); 404 } 405 return false; 406 } 407 408 // Must be after all calls to PROFILE_ASAN_MAPPING(). 409 static const uptr kAsanMappingProfileSize = __LINE__; 410 411 } // namespace __asan 412 413 #endif // __cplusplus 414 415 #endif // ASAN_MAPPING_H 416