asan_mapping.h revision 327952
1//===-- asan_mapping.h ------------------------------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file is a part of AddressSanitizer, an address sanity checker. 11// 12// Defines ASan memory mapping. 13//===----------------------------------------------------------------------===// 14#ifndef ASAN_MAPPING_H 15#define ASAN_MAPPING_H 16 17#include "asan_internal.h" 18 19// The full explanation of the memory mapping could be found here: 20// https://github.com/google/sanitizers/wiki/AddressSanitizerAlgorithm 21// 22// Typical shadow mapping on Linux/x86_64 with SHADOW_OFFSET == 0x00007fff8000: 23// || `[0x10007fff8000, 0x7fffffffffff]` || HighMem || 24// || `[0x02008fff7000, 0x10007fff7fff]` || HighShadow || 25// || `[0x00008fff7000, 0x02008fff6fff]` || ShadowGap || 26// || `[0x00007fff8000, 0x00008fff6fff]` || LowShadow || 27// || `[0x000000000000, 0x00007fff7fff]` || LowMem || 28// 29// When SHADOW_OFFSET is zero (-pie): 30// || `[0x100000000000, 0x7fffffffffff]` || HighMem || 31// || `[0x020000000000, 0x0fffffffffff]` || HighShadow || 32// || `[0x000000040000, 0x01ffffffffff]` || ShadowGap || 33// 34// Special case when something is already mapped between 35// 0x003000000000 and 0x005000000000 (e.g. when prelink is installed): 36// || `[0x10007fff8000, 0x7fffffffffff]` || HighMem || 37// || `[0x02008fff7000, 0x10007fff7fff]` || HighShadow || 38// || `[0x005000000000, 0x02008fff6fff]` || ShadowGap3 || 39// || `[0x003000000000, 0x004fffffffff]` || MidMem || 40// || `[0x000a7fff8000, 0x002fffffffff]` || ShadowGap2 || 41// || `[0x00067fff8000, 0x000a7fff7fff]` || MidShadow || 42// || `[0x00008fff7000, 0x00067fff7fff]` || ShadowGap || 43// || `[0x00007fff8000, 0x00008fff6fff]` || LowShadow || 44// || `[0x000000000000, 0x00007fff7fff]` || LowMem || 45// 46// Default Linux/i386 mapping on x86_64 machine: 47// || `[0x40000000, 0xffffffff]` || HighMem || 48// || `[0x28000000, 0x3fffffff]` || HighShadow || 49// || `[0x24000000, 0x27ffffff]` || ShadowGap || 50// || `[0x20000000, 0x23ffffff]` || LowShadow || 51// || `[0x00000000, 0x1fffffff]` || LowMem || 52// 53// Default Linux/i386 mapping on i386 machine 54// (addresses starting with 0xc0000000 are reserved 55// for kernel and thus not sanitized): 56// || `[0x38000000, 0xbfffffff]` || HighMem || 57// || `[0x27000000, 0x37ffffff]` || HighShadow || 58// || `[0x24000000, 0x26ffffff]` || ShadowGap || 59// || `[0x20000000, 0x23ffffff]` || LowShadow || 60// || `[0x00000000, 0x1fffffff]` || LowMem || 61// 62// Default Linux/MIPS32 mapping: 63// || `[0x2aaa0000, 0xffffffff]` || HighMem || 64// || `[0x0fff4000, 0x2aa9ffff]` || HighShadow || 65// || `[0x0bff4000, 0x0fff3fff]` || ShadowGap || 66// || `[0x0aaa0000, 0x0bff3fff]` || LowShadow || 67// || `[0x00000000, 0x0aa9ffff]` || LowMem || 68// 69// Default Linux/MIPS64 mapping: 70// || `[0x4000000000, 0xffffffffff]` || HighMem || 71// || `[0x2800000000, 0x3fffffffff]` || HighShadow || 72// || `[0x2400000000, 0x27ffffffff]` || ShadowGap || 73// || `[0x2000000000, 0x23ffffffff]` || LowShadow || 74// || `[0x0000000000, 0x1fffffffff]` || LowMem || 75// 76// Default Linux/AArch64 (39-bit VMA) mapping: 77// || `[0x2000000000, 0x7fffffffff]` || highmem || 78// || `[0x1400000000, 0x1fffffffff]` || highshadow || 79// || `[0x1200000000, 0x13ffffffff]` || shadowgap || 80// || `[0x1000000000, 0x11ffffffff]` || lowshadow || 81// || `[0x0000000000, 0x0fffffffff]` || lowmem || 82// 83// Default Linux/AArch64 (42-bit VMA) mapping: 84// || `[0x10000000000, 0x3ffffffffff]` || highmem || 85// || `[0x0a000000000, 0x0ffffffffff]` || highshadow || 86// || `[0x09000000000, 0x09fffffffff]` || shadowgap || 87// || `[0x08000000000, 0x08fffffffff]` || lowshadow || 88// || `[0x00000000000, 0x07fffffffff]` || lowmem || 89// 90// Default Linux/S390 mapping: 91// || `[0x30000000, 0x7fffffff]` || HighMem || 92// || `[0x26000000, 0x2fffffff]` || HighShadow || 93// || `[0x24000000, 0x25ffffff]` || ShadowGap || 94// || `[0x20000000, 0x23ffffff]` || LowShadow || 95// || `[0x00000000, 0x1fffffff]` || LowMem || 96// 97// Default Linux/SystemZ mapping: 98// || `[0x14000000000000, 0x1fffffffffffff]` || HighMem || 99// || `[0x12800000000000, 0x13ffffffffffff]` || HighShadow || 100// || `[0x12000000000000, 0x127fffffffffff]` || ShadowGap || 101// || `[0x10000000000000, 0x11ffffffffffff]` || LowShadow || 102// || `[0x00000000000000, 0x0fffffffffffff]` || LowMem || 103// 104// Shadow mapping on FreeBSD/x86-64 with SHADOW_OFFSET == 0x400000000000: 105// || `[0x500000000000, 0x7fffffffffff]` || HighMem || 106// || `[0x4a0000000000, 0x4fffffffffff]` || HighShadow || 107// || `[0x480000000000, 0x49ffffffffff]` || ShadowGap || 108// || `[0x400000000000, 0x47ffffffffff]` || LowShadow || 109// || `[0x000000000000, 0x3fffffffffff]` || LowMem || 110// 111// Shadow mapping on FreeBSD/i386 with SHADOW_OFFSET == 0x40000000: 112// || `[0x60000000, 0xffffffff]` || HighMem || 113// || `[0x4c000000, 0x5fffffff]` || HighShadow || 114// || `[0x48000000, 0x4bffffff]` || ShadowGap || 115// || `[0x40000000, 0x47ffffff]` || LowShadow || 116// || `[0x00000000, 0x3fffffff]` || LowMem || 117// 118// Shadow mapping on NetBSD/x86-64 with SHADOW_OFFSET == 0x400000000000: 119// || `[0x4feffffffe01, 0x7f7ffffff000]` || HighMem || 120// || `[0x49fdffffffc0, 0x4feffffffe00]` || HighShadow || 121// || `[0x480000000000, 0x49fdffffffbf]` || ShadowGap || 122// || `[0x400000000000, 0x47ffffffffff]` || LowShadow || 123// || `[0x000000000000, 0x3fffffffffff]` || LowMem || 124// 125// Default Windows/i386 mapping: 126// (the exact location of HighShadow/HighMem may vary depending 127// on WoW64, /LARGEADDRESSAWARE, etc). 128// || `[0x50000000, 0xffffffff]` || HighMem || 129// || `[0x3a000000, 0x4fffffff]` || HighShadow || 130// || `[0x36000000, 0x39ffffff]` || ShadowGap || 131// || `[0x30000000, 0x35ffffff]` || LowShadow || 132// || `[0x00000000, 0x2fffffff]` || LowMem || 133 134#if defined(ASAN_SHADOW_SCALE) 135static const u64 kDefaultShadowScale = ASAN_SHADOW_SCALE; 136#else 137static const u64 kDefaultShadowScale = 3; 138#endif 139static const u64 kDefaultShadowSentinel = ~(uptr)0; 140static const u64 kDefaultShadowOffset32 = 1ULL << 29; // 0x20000000 141static const u64 kDefaultShadowOffset64 = 1ULL << 44; 142static const u64 kDefaultShort64bitShadowOffset = 143 0x7FFFFFFF & (~0xFFFULL << kDefaultShadowScale); // < 2G. 144static const u64 kIosShadowOffset32 = 1ULL << 30; // 0x40000000 145static const u64 kIosShadowOffset64 = 0x120200000; 146static const u64 kIosSimShadowOffset32 = 1ULL << 30; 147static const u64 kIosSimShadowOffset64 = kDefaultShadowOffset64; 148static const u64 kAArch64_ShadowOffset64 = 1ULL << 36; 149static const u64 kMIPS32_ShadowOffset32 = 0x0aaa0000; 150static const u64 kMIPS64_ShadowOffset64 = 1ULL << 37; 151static const u64 kPPC64_ShadowOffset64 = 1ULL << 44; 152static const u64 kSystemZ_ShadowOffset64 = 1ULL << 52; 153static const u64 kFreeBSD_ShadowOffset32 = 1ULL << 30; // 0x40000000 154static const u64 kFreeBSD_ShadowOffset64 = 1ULL << 46; // 0x400000000000 155static const u64 kNetBSD_ShadowOffset64 = 1ULL << 46; // 0x400000000000 156static const u64 kWindowsShadowOffset32 = 3ULL << 28; // 0x30000000 157 158#define SHADOW_SCALE kDefaultShadowScale 159 160#if SANITIZER_FUCHSIA 161# define SHADOW_OFFSET (0) 162#elif SANITIZER_WORDSIZE == 32 163# if SANITIZER_ANDROID 164# define SHADOW_OFFSET __asan_shadow_memory_dynamic_address 165# elif defined(__mips__) 166# define SHADOW_OFFSET kMIPS32_ShadowOffset32 167# elif SANITIZER_FREEBSD 168# define SHADOW_OFFSET kFreeBSD_ShadowOffset32 169# elif SANITIZER_WINDOWS 170# define SHADOW_OFFSET kWindowsShadowOffset32 171# elif SANITIZER_IOS 172# if SANITIZER_IOSSIM 173# define SHADOW_OFFSET kIosSimShadowOffset32 174# else 175# define SHADOW_OFFSET kIosShadowOffset32 176# endif 177# else 178# define SHADOW_OFFSET kDefaultShadowOffset32 179# endif 180#else 181# if SANITIZER_IOS 182# if SANITIZER_IOSSIM 183# define SHADOW_OFFSET kIosSimShadowOffset64 184# else 185# define SHADOW_OFFSET __asan_shadow_memory_dynamic_address 186# endif 187# elif defined(__aarch64__) 188# define SHADOW_OFFSET kAArch64_ShadowOffset64 189# elif defined(__powerpc64__) 190# define SHADOW_OFFSET kPPC64_ShadowOffset64 191# elif defined(__s390x__) 192# define SHADOW_OFFSET kSystemZ_ShadowOffset64 193# elif SANITIZER_FREEBSD 194# define SHADOW_OFFSET kFreeBSD_ShadowOffset64 195# elif SANITIZER_NETBSD 196# define SHADOW_OFFSET kNetBSD_ShadowOffset64 197# elif SANITIZER_MAC 198# define SHADOW_OFFSET kDefaultShadowOffset64 199# elif defined(__mips64) 200# define SHADOW_OFFSET kMIPS64_ShadowOffset64 201# elif SANITIZER_WINDOWS64 202# define SHADOW_OFFSET __asan_shadow_memory_dynamic_address 203# else 204# define SHADOW_OFFSET kDefaultShort64bitShadowOffset 205# endif 206#endif 207 208#if SANITIZER_ANDROID && defined(__arm__) 209# define ASAN_PREMAP_SHADOW 1 210#else 211# define ASAN_PREMAP_SHADOW 0 212#endif 213 214#define SHADOW_GRANULARITY (1ULL << SHADOW_SCALE) 215#define MEM_TO_SHADOW(mem) (((mem) >> SHADOW_SCALE) + (SHADOW_OFFSET)) 216 217#define kLowMemBeg 0 218#define kLowMemEnd (SHADOW_OFFSET ? SHADOW_OFFSET - 1 : 0) 219 220#define kLowShadowBeg SHADOW_OFFSET 221#define kLowShadowEnd MEM_TO_SHADOW(kLowMemEnd) 222 223#define kHighMemBeg (MEM_TO_SHADOW(kHighMemEnd) + 1) 224 225#define kHighShadowBeg MEM_TO_SHADOW(kHighMemBeg) 226#define kHighShadowEnd MEM_TO_SHADOW(kHighMemEnd) 227 228# define kMidShadowBeg MEM_TO_SHADOW(kMidMemBeg) 229# define kMidShadowEnd MEM_TO_SHADOW(kMidMemEnd) 230 231// With the zero shadow base we can not actually map pages starting from 0. 232// This constant is somewhat arbitrary. 233#define kZeroBaseShadowStart 0 234#define kZeroBaseMaxShadowStart (1 << 18) 235 236#define kShadowGapBeg (kLowShadowEnd ? kLowShadowEnd + 1 \ 237 : kZeroBaseShadowStart) 238#define kShadowGapEnd ((kMidMemBeg ? kMidShadowBeg : kHighShadowBeg) - 1) 239 240#define kShadowGap2Beg (kMidMemBeg ? kMidShadowEnd + 1 : 0) 241#define kShadowGap2End (kMidMemBeg ? kMidMemBeg - 1 : 0) 242 243#define kShadowGap3Beg (kMidMemBeg ? kMidMemEnd + 1 : 0) 244#define kShadowGap3End (kMidMemBeg ? kHighShadowBeg - 1 : 0) 245 246#define DO_ASAN_MAPPING_PROFILE 0 // Set to 1 to profile the functions below. 247 248#if DO_ASAN_MAPPING_PROFILE 249# define PROFILE_ASAN_MAPPING() AsanMappingProfile[__LINE__]++; 250#else 251# define PROFILE_ASAN_MAPPING() 252#endif 253 254// If 1, all shadow boundaries are constants. 255// Don't set to 1 other than for testing. 256#define ASAN_FIXED_MAPPING 0 257 258namespace __asan { 259 260extern uptr AsanMappingProfile[]; 261 262#if ASAN_FIXED_MAPPING 263// Fixed mapping for 64-bit Linux. Mostly used for performance comparison 264// with non-fixed mapping. As of r175253 (Feb 2013) the performance 265// difference between fixed and non-fixed mapping is below the noise level. 266static uptr kHighMemEnd = 0x7fffffffffffULL; 267static uptr kMidMemBeg = 0x3000000000ULL; 268static uptr kMidMemEnd = 0x4fffffffffULL; 269#else 270extern uptr kHighMemEnd, kMidMemBeg, kMidMemEnd; // Initialized in __asan_init. 271#endif 272 273static inline bool AddrIsInLowMem(uptr a) { 274 PROFILE_ASAN_MAPPING(); 275 return a < kLowMemEnd; 276} 277 278static inline bool AddrIsInLowShadow(uptr a) { 279 PROFILE_ASAN_MAPPING(); 280 return a >= kLowShadowBeg && a <= kLowShadowEnd; 281} 282 283static inline bool AddrIsInHighMem(uptr a) { 284 PROFILE_ASAN_MAPPING(); 285 return a >= kHighMemBeg && a <= kHighMemEnd; 286} 287 288static inline bool AddrIsInMidMem(uptr a) { 289 PROFILE_ASAN_MAPPING(); 290 return kMidMemBeg && a >= kMidMemBeg && a <= kMidMemEnd; 291} 292 293static inline bool AddrIsInShadowGap(uptr a) { 294 PROFILE_ASAN_MAPPING(); 295 if (kMidMemBeg) { 296 if (a <= kShadowGapEnd) 297 return SHADOW_OFFSET == 0 || a >= kShadowGapBeg; 298 return (a >= kShadowGap2Beg && a <= kShadowGap2End) || 299 (a >= kShadowGap3Beg && a <= kShadowGap3End); 300 } 301 // In zero-based shadow mode we treat addresses near zero as addresses 302 // in shadow gap as well. 303 if (SHADOW_OFFSET == 0) 304 return a <= kShadowGapEnd; 305 return a >= kShadowGapBeg && a <= kShadowGapEnd; 306} 307 308static inline bool AddrIsInMem(uptr a) { 309 PROFILE_ASAN_MAPPING(); 310 return AddrIsInLowMem(a) || AddrIsInMidMem(a) || AddrIsInHighMem(a) || 311 (flags()->protect_shadow_gap == 0 && AddrIsInShadowGap(a)); 312} 313 314static inline uptr MemToShadow(uptr p) { 315 PROFILE_ASAN_MAPPING(); 316 CHECK(AddrIsInMem(p)); 317 return MEM_TO_SHADOW(p); 318} 319 320static inline bool AddrIsInHighShadow(uptr a) { 321 PROFILE_ASAN_MAPPING(); 322 return a >= kHighShadowBeg && a <= kHighMemEnd; 323} 324 325static inline bool AddrIsInMidShadow(uptr a) { 326 PROFILE_ASAN_MAPPING(); 327 return kMidMemBeg && a >= kMidShadowBeg && a <= kMidMemEnd; 328} 329 330static inline bool AddrIsInShadow(uptr a) { 331 PROFILE_ASAN_MAPPING(); 332 return AddrIsInLowShadow(a) || AddrIsInMidShadow(a) || AddrIsInHighShadow(a); 333} 334 335static inline bool AddrIsAlignedByGranularity(uptr a) { 336 PROFILE_ASAN_MAPPING(); 337 return (a & (SHADOW_GRANULARITY - 1)) == 0; 338} 339 340static inline bool AddressIsPoisoned(uptr a) { 341 PROFILE_ASAN_MAPPING(); 342 const uptr kAccessSize = 1; 343 u8 *shadow_address = (u8*)MEM_TO_SHADOW(a); 344 s8 shadow_value = *shadow_address; 345 if (shadow_value) { 346 u8 last_accessed_byte = (a & (SHADOW_GRANULARITY - 1)) 347 + kAccessSize - 1; 348 return (last_accessed_byte >= shadow_value); 349 } 350 return false; 351} 352 353// Must be after all calls to PROFILE_ASAN_MAPPING(). 354static const uptr kAsanMappingProfileSize = __LINE__; 355 356} // namespace __asan 357 358#endif // ASAN_MAPPING_H 359