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 "asan_internal.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/AArch64 (39-bit VMA) mapping: 76// || `[0x2000000000, 0x7fffffffff]` || highmem || 77// || `[0x1400000000, 0x1fffffffff]` || highshadow || 78// || `[0x1200000000, 0x13ffffffff]` || shadowgap || 79// || `[0x1000000000, 0x11ffffffff]` || lowshadow || 80// || `[0x0000000000, 0x0fffffffff]` || lowmem || 81// 82// Default Linux/AArch64 (42-bit VMA) mapping: 83// || `[0x10000000000, 0x3ffffffffff]` || highmem || 84// || `[0x0a000000000, 0x0ffffffffff]` || highshadow || 85// || `[0x09000000000, 0x09fffffffff]` || shadowgap || 86// || `[0x08000000000, 0x08fffffffff]` || lowshadow || 87// || `[0x00000000000, 0x07fffffffff]` || lowmem || 88// 89// Default Linux/S390 mapping: 90// || `[0x30000000, 0x7fffffff]` || HighMem || 91// || `[0x26000000, 0x2fffffff]` || HighShadow || 92// || `[0x24000000, 0x25ffffff]` || ShadowGap || 93// || `[0x20000000, 0x23ffffff]` || LowShadow || 94// || `[0x00000000, 0x1fffffff]` || LowMem || 95// 96// Default Linux/SystemZ mapping: 97// || `[0x14000000000000, 0x1fffffffffffff]` || HighMem || 98// || `[0x12800000000000, 0x13ffffffffffff]` || HighShadow || 99// || `[0x12000000000000, 0x127fffffffffff]` || ShadowGap || 100// || `[0x10000000000000, 0x11ffffffffffff]` || LowShadow || 101// || `[0x00000000000000, 0x0fffffffffffff]` || LowMem || 102// 103// Default Linux/SPARC64 (52-bit VMA) mapping: 104// || `[0x8000000000000, 0xfffffffffffff]` || HighMem || 105// || `[0x1080000000000, 0x207ffffffffff]` || HighShadow || 106// || `[0x0090000000000, 0x107ffffffffff]` || ShadowGap || 107// || `[0x0080000000000, 0x008ffffffffff]` || LowShadow || 108// || `[0x0000000000000, 0x007ffffffffff]` || LowMem || 109// 110// Shadow mapping on FreeBSD/x86-64 with SHADOW_OFFSET == 0x400000000000: 111// || `[0x500000000000, 0x7fffffffffff]` || HighMem || 112// || `[0x4a0000000000, 0x4fffffffffff]` || HighShadow || 113// || `[0x480000000000, 0x49ffffffffff]` || ShadowGap || 114// || `[0x400000000000, 0x47ffffffffff]` || LowShadow || 115// || `[0x000000000000, 0x3fffffffffff]` || LowMem || 116// 117// Shadow mapping on FreeBSD/i386 with SHADOW_OFFSET == 0x40000000: 118// || `[0x60000000, 0xffffffff]` || HighMem || 119// || `[0x4c000000, 0x5fffffff]` || HighShadow || 120// || `[0x48000000, 0x4bffffff]` || ShadowGap || 121// || `[0x40000000, 0x47ffffff]` || LowShadow || 122// || `[0x00000000, 0x3fffffff]` || LowMem || 123// 124// Shadow mapping on NetBSD/x86-64 with SHADOW_OFFSET == 0x400000000000: 125// || `[0x4feffffffe01, 0x7f7ffffff000]` || HighMem || 126// || `[0x49fdffffffc0, 0x4feffffffe00]` || HighShadow || 127// || `[0x480000000000, 0x49fdffffffbf]` || ShadowGap || 128// || `[0x400000000000, 0x47ffffffffff]` || LowShadow || 129// || `[0x000000000000, 0x3fffffffffff]` || LowMem || 130// 131// Shadow mapping on NetBSD/i386 with SHADOW_OFFSET == 0x40000000: 132// || `[0x60000000, 0xfffff000]` || HighMem || 133// || `[0x4c000000, 0x5fffffff]` || HighShadow || 134// || `[0x48000000, 0x4bffffff]` || ShadowGap || 135// || `[0x40000000, 0x47ffffff]` || LowShadow || 136// || `[0x00000000, 0x3fffffff]` || LowMem || 137// 138// Default Windows/i386 mapping: 139// (the exact location of HighShadow/HighMem may vary depending 140// on WoW64, /LARGEADDRESSAWARE, etc). 141// || `[0x50000000, 0xffffffff]` || HighMem || 142// || `[0x3a000000, 0x4fffffff]` || HighShadow || 143// || `[0x36000000, 0x39ffffff]` || ShadowGap || 144// || `[0x30000000, 0x35ffffff]` || LowShadow || 145// || `[0x00000000, 0x2fffffff]` || LowMem || 146// 147// Shadow mapping on Myriad2 (for shadow scale 5): 148// || `[0x9ff80000, 0x9fffffff]` || ShadowGap || 149// || `[0x9f000000, 0x9ff7ffff]` || LowShadow || 150// || `[0x80000000, 0x9effffff]` || LowMem || 151// || `[0x00000000, 0x7fffffff]` || Ignored || 152 153#if defined(ASAN_SHADOW_SCALE) 154static const u64 kDefaultShadowScale = ASAN_SHADOW_SCALE; 155#else 156static const u64 kDefaultShadowScale = SANITIZER_MYRIAD2 ? 5 : 3; 157#endif 158static const u64 kDefaultShadowSentinel = ~(uptr)0; 159static const u64 kDefaultShadowOffset32 = 1ULL << 29; // 0x20000000 160static const u64 kDefaultShadowOffset64 = 1ULL << 44; 161static const u64 kDefaultShort64bitShadowOffset = 162 0x7FFFFFFF & (~0xFFFULL << kDefaultShadowScale); // < 2G. 163static const u64 kAArch64_ShadowOffset64 = 1ULL << 36; 164static const u64 kMIPS32_ShadowOffset32 = 0x0aaa0000; 165static const u64 kMIPS64_ShadowOffset64 = 1ULL << 37; 166static const u64 kPPC64_ShadowOffset64 = 1ULL << 44; 167static const u64 kSystemZ_ShadowOffset64 = 1ULL << 52; 168static const u64 kSPARC64_ShadowOffset64 = 1ULL << 43; // 0x80000000000 169static const u64 kFreeBSD_ShadowOffset32 = 1ULL << 30; // 0x40000000 170static const u64 kFreeBSD_ShadowOffset64 = 1ULL << 46; // 0x400000000000 171static const u64 kNetBSD_ShadowOffset32 = 1ULL << 30; // 0x40000000 172static const u64 kNetBSD_ShadowOffset64 = 1ULL << 46; // 0x400000000000 173static const u64 kWindowsShadowOffset32 = 3ULL << 28; // 0x30000000 174 175static const u64 kMyriadMemoryOffset32 = 0x80000000ULL; 176static const u64 kMyriadMemorySize32 = 0x20000000ULL; 177static const u64 kMyriadMemoryEnd32 = 178 kMyriadMemoryOffset32 + kMyriadMemorySize32 - 1; 179static const u64 kMyriadShadowOffset32 = 180 (kMyriadMemoryOffset32 + kMyriadMemorySize32 - 181 (kMyriadMemorySize32 >> kDefaultShadowScale)); 182static const u64 kMyriadCacheBitMask32 = 0x40000000ULL; 183 184#define SHADOW_SCALE kDefaultShadowScale 185 186#if SANITIZER_FUCHSIA 187# define SHADOW_OFFSET (0) 188#elif SANITIZER_WORDSIZE == 32 189# if SANITIZER_ANDROID 190# define SHADOW_OFFSET __asan_shadow_memory_dynamic_address 191# elif defined(__mips__) 192# define SHADOW_OFFSET kMIPS32_ShadowOffset32 193# elif SANITIZER_FREEBSD 194# define SHADOW_OFFSET kFreeBSD_ShadowOffset32 195# elif SANITIZER_NETBSD 196# define SHADOW_OFFSET kNetBSD_ShadowOffset32 197# elif SANITIZER_WINDOWS 198# define SHADOW_OFFSET kWindowsShadowOffset32 199# elif SANITIZER_IOS 200# define SHADOW_OFFSET __asan_shadow_memory_dynamic_address 201# elif SANITIZER_MYRIAD2 202# define SHADOW_OFFSET kMyriadShadowOffset32 203# else 204# define SHADOW_OFFSET kDefaultShadowOffset32 205# endif 206#else 207# if SANITIZER_IOS 208# define SHADOW_OFFSET __asan_shadow_memory_dynamic_address 209# elif defined(__aarch64__) 210# define SHADOW_OFFSET kAArch64_ShadowOffset64 211# elif defined(__powerpc64__) 212# define SHADOW_OFFSET kPPC64_ShadowOffset64 213# elif defined(__s390x__) 214# define SHADOW_OFFSET kSystemZ_ShadowOffset64 215# elif SANITIZER_FREEBSD 216# define SHADOW_OFFSET kFreeBSD_ShadowOffset64 217# elif SANITIZER_NETBSD 218# define SHADOW_OFFSET kNetBSD_ShadowOffset64 219# elif SANITIZER_MAC 220# define SHADOW_OFFSET kDefaultShadowOffset64 221# elif defined(__mips64) 222# define SHADOW_OFFSET kMIPS64_ShadowOffset64 223#elif defined(__sparc__) 224#define SHADOW_OFFSET kSPARC64_ShadowOffset64 225# elif SANITIZER_WINDOWS64 226# define SHADOW_OFFSET __asan_shadow_memory_dynamic_address 227# else 228# define SHADOW_OFFSET kDefaultShort64bitShadowOffset 229# endif 230#endif 231 232#if SANITIZER_ANDROID && defined(__arm__) 233# define ASAN_PREMAP_SHADOW 1 234#else 235# define ASAN_PREMAP_SHADOW 0 236#endif 237 238#define SHADOW_GRANULARITY (1ULL << SHADOW_SCALE) 239 240#define DO_ASAN_MAPPING_PROFILE 0 // Set to 1 to profile the functions below. 241 242#if DO_ASAN_MAPPING_PROFILE 243# define PROFILE_ASAN_MAPPING() AsanMappingProfile[__LINE__]++; 244#else 245# define PROFILE_ASAN_MAPPING() 246#endif 247 248// If 1, all shadow boundaries are constants. 249// Don't set to 1 other than for testing. 250#define ASAN_FIXED_MAPPING 0 251 252namespace __asan { 253 254extern uptr AsanMappingProfile[]; 255 256#if ASAN_FIXED_MAPPING 257// Fixed mapping for 64-bit Linux. Mostly used for performance comparison 258// with non-fixed mapping. As of r175253 (Feb 2013) the performance 259// difference between fixed and non-fixed mapping is below the noise level. 260static uptr kHighMemEnd = 0x7fffffffffffULL; 261static uptr kMidMemBeg = 0x3000000000ULL; 262static uptr kMidMemEnd = 0x4fffffffffULL; 263#else 264extern uptr kHighMemEnd, kMidMemBeg, kMidMemEnd; // Initialized in __asan_init. 265#endif 266 267} // namespace __asan 268 269#if SANITIZER_MYRIAD2 270#include "asan_mapping_myriad.h" 271#elif defined(__sparc__) && SANITIZER_WORDSIZE == 64 272#include "asan_mapping_sparc64.h" 273#else 274#define MEM_TO_SHADOW(mem) (((mem) >> SHADOW_SCALE) + (SHADOW_OFFSET)) 275 276#define kLowMemBeg 0 277#define kLowMemEnd (SHADOW_OFFSET ? SHADOW_OFFSET - 1 : 0) 278 279#define kLowShadowBeg SHADOW_OFFSET 280#define kLowShadowEnd MEM_TO_SHADOW(kLowMemEnd) 281 282#define kHighMemBeg (MEM_TO_SHADOW(kHighMemEnd) + 1) 283 284#define kHighShadowBeg MEM_TO_SHADOW(kHighMemBeg) 285#define kHighShadowEnd MEM_TO_SHADOW(kHighMemEnd) 286 287# define kMidShadowBeg MEM_TO_SHADOW(kMidMemBeg) 288# define kMidShadowEnd MEM_TO_SHADOW(kMidMemEnd) 289 290// With the zero shadow base we can not actually map pages starting from 0. 291// This constant is somewhat arbitrary. 292#define kZeroBaseShadowStart 0 293#define kZeroBaseMaxShadowStart (1 << 18) 294 295#define kShadowGapBeg (kLowShadowEnd ? kLowShadowEnd + 1 \ 296 : kZeroBaseShadowStart) 297#define kShadowGapEnd ((kMidMemBeg ? kMidShadowBeg : kHighShadowBeg) - 1) 298 299#define kShadowGap2Beg (kMidMemBeg ? kMidShadowEnd + 1 : 0) 300#define kShadowGap2End (kMidMemBeg ? kMidMemBeg - 1 : 0) 301 302#define kShadowGap3Beg (kMidMemBeg ? kMidMemEnd + 1 : 0) 303#define kShadowGap3End (kMidMemBeg ? kHighShadowBeg - 1 : 0) 304 305namespace __asan { 306 307static inline bool AddrIsInLowMem(uptr a) { 308 PROFILE_ASAN_MAPPING(); 309 return a <= kLowMemEnd; 310} 311 312static inline bool AddrIsInLowShadow(uptr a) { 313 PROFILE_ASAN_MAPPING(); 314 return a >= kLowShadowBeg && a <= kLowShadowEnd; 315} 316 317static inline bool AddrIsInMidMem(uptr a) { 318 PROFILE_ASAN_MAPPING(); 319 return kMidMemBeg && a >= kMidMemBeg && a <= kMidMemEnd; 320} 321 322static inline bool AddrIsInMidShadow(uptr a) { 323 PROFILE_ASAN_MAPPING(); 324 return kMidMemBeg && a >= kMidShadowBeg && a <= kMidShadowEnd; 325} 326 327static inline bool AddrIsInHighMem(uptr a) { 328 PROFILE_ASAN_MAPPING(); 329 return kHighMemBeg && a >= kHighMemBeg && a <= kHighMemEnd; 330} 331 332static inline bool AddrIsInHighShadow(uptr a) { 333 PROFILE_ASAN_MAPPING(); 334 return kHighMemBeg && a >= kHighShadowBeg && a <= kHighShadowEnd; 335} 336 337static inline bool AddrIsInShadowGap(uptr a) { 338 PROFILE_ASAN_MAPPING(); 339 if (kMidMemBeg) { 340 if (a <= kShadowGapEnd) 341 return SHADOW_OFFSET == 0 || a >= kShadowGapBeg; 342 return (a >= kShadowGap2Beg && a <= kShadowGap2End) || 343 (a >= kShadowGap3Beg && a <= kShadowGap3End); 344 } 345 // In zero-based shadow mode we treat addresses near zero as addresses 346 // in shadow gap as well. 347 if (SHADOW_OFFSET == 0) 348 return a <= kShadowGapEnd; 349 return a >= kShadowGapBeg && a <= kShadowGapEnd; 350} 351 352} // namespace __asan 353 354#endif // SANITIZER_MYRIAD2 355 356namespace __asan { 357 358static inline bool AddrIsInMem(uptr a) { 359 PROFILE_ASAN_MAPPING(); 360 return AddrIsInLowMem(a) || AddrIsInMidMem(a) || AddrIsInHighMem(a) || 361 (flags()->protect_shadow_gap == 0 && AddrIsInShadowGap(a)); 362} 363 364static inline uptr MemToShadow(uptr p) { 365 PROFILE_ASAN_MAPPING(); 366 CHECK(AddrIsInMem(p)); 367 return MEM_TO_SHADOW(p); 368} 369 370static inline bool AddrIsInShadow(uptr a) { 371 PROFILE_ASAN_MAPPING(); 372 return AddrIsInLowShadow(a) || AddrIsInMidShadow(a) || AddrIsInHighShadow(a); 373} 374 375static inline bool AddrIsAlignedByGranularity(uptr a) { 376 PROFILE_ASAN_MAPPING(); 377 return (a & (SHADOW_GRANULARITY - 1)) == 0; 378} 379 380static inline bool AddressIsPoisoned(uptr a) { 381 PROFILE_ASAN_MAPPING(); 382 if (SANITIZER_MYRIAD2 && !AddrIsInMem(a) && !AddrIsInShadow(a)) 383 return false; 384 const uptr kAccessSize = 1; 385 u8 *shadow_address = (u8*)MEM_TO_SHADOW(a); 386 s8 shadow_value = *shadow_address; 387 if (shadow_value) { 388 u8 last_accessed_byte = (a & (SHADOW_GRANULARITY - 1)) 389 + kAccessSize - 1; 390 return (last_accessed_byte >= shadow_value); 391 } 392 return false; 393} 394 395// Must be after all calls to PROFILE_ASAN_MAPPING(). 396static const uptr kAsanMappingProfileSize = __LINE__; 397 398} // namespace __asan 399 400#endif // ASAN_MAPPING_H 401