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 0x0000100000000000 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 222static const u64 kDefaultShadowSentinel = ~(uptr)0; 223 224# if defined(ASAN_SHADOW_OFFSET_CONST) 225static 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 253namespace __asan { 254 255extern 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. 261static uptr kHighMemEnd = 0x7fffffffffffULL; 262static uptr kMidMemBeg = 0x3000000000ULL; 263static uptr kMidMemEnd = 0x4fffffffffULL; 264# else 265extern 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 307namespace __asan { 308 309static inline bool AddrIsInLowMem(uptr a) { 310 PROFILE_ASAN_MAPPING(); 311 return a <= kLowMemEnd; 312} 313 314static inline bool AddrIsInLowShadow(uptr a) { 315 PROFILE_ASAN_MAPPING(); 316 return a >= kLowShadowBeg && a <= kLowShadowEnd; 317} 318 319static inline bool AddrIsInMidMem(uptr a) { 320 PROFILE_ASAN_MAPPING(); 321 return kMidMemBeg && a >= kMidMemBeg && a <= kMidMemEnd; 322} 323 324static inline bool AddrIsInMidShadow(uptr a) { 325 PROFILE_ASAN_MAPPING(); 326 return kMidMemBeg && a >= kMidShadowBeg && a <= kMidShadowEnd; 327} 328 329static inline bool AddrIsInHighMem(uptr a) { 330 PROFILE_ASAN_MAPPING(); 331 return kHighMemBeg && a >= kHighMemBeg && a <= kHighMemEnd; 332} 333 334static inline bool AddrIsInHighShadow(uptr a) { 335 PROFILE_ASAN_MAPPING(); 336 return kHighMemBeg && a >= kHighShadowBeg && a <= kHighShadowEnd; 337} 338 339static 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 358namespace __asan { 359 360static inline uptr MemToShadowSize(uptr size) { 361 return size >> ASAN_SHADOW_SCALE; 362} 363 364static 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 370static inline uptr MemToShadow(uptr p) { 371 PROFILE_ASAN_MAPPING(); 372 CHECK(AddrIsInMem(p)); 373 return MEM_TO_SHADOW(p); 374} 375 376static inline bool AddrIsInShadow(uptr a) { 377 PROFILE_ASAN_MAPPING(); 378 return AddrIsInLowShadow(a) || AddrIsInMidShadow(a) || AddrIsInHighShadow(a); 379} 380 381static inline uptr ShadowToMem(uptr p) { 382 PROFILE_ASAN_MAPPING(); 383 CHECK(AddrIsInShadow(p)); 384 return SHADOW_TO_MEM(p); 385} 386 387static inline bool AddrIsAlignedByGranularity(uptr a) { 388 PROFILE_ASAN_MAPPING(); 389 return (a & (ASAN_SHADOW_GRANULARITY - 1)) == 0; 390} 391 392static 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(). 406static const uptr kAsanMappingProfileSize = __LINE__; 407 408} // namespace __asan 409 410#endif // __cplusplus 411 412#endif // ASAN_MAPPING_H 413