asan_mapping.h revision 309124
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// Default Windows/i386 mapping: 119// (the exact location of HighShadow/HighMem may vary depending 120// on WoW64, /LARGEADDRESSAWARE, etc). 121// || `[0x50000000, 0xffffffff]` || HighMem || 122// || `[0x3a000000, 0x4fffffff]` || HighShadow || 123// || `[0x36000000, 0x39ffffff]` || ShadowGap || 124// || `[0x30000000, 0x35ffffff]` || LowShadow || 125// || `[0x00000000, 0x2fffffff]` || LowMem || 126 127static const u64 kDefaultShadowScale = 3; 128static const u64 kDefaultShadowOffset32 = 1ULL << 29; // 0x20000000 129static const u64 kDefaultShadowOffset64 = 1ULL << 44; 130static const u64 kDefaultShort64bitShadowOffset = 0x7FFF8000; // < 2G. 131static const u64 kIosShadowOffset32 = 1ULL << 30; // 0x40000000 132static const u64 kIosShadowOffset64 = 0x120200000; 133static const u64 kIosSimShadowOffset32 = 1ULL << 30; 134static const u64 kIosSimShadowOffset64 = kDefaultShadowOffset64; 135static const u64 kAArch64_ShadowOffset64 = 1ULL << 36; 136static const u64 kMIPS32_ShadowOffset32 = 0x0aaa0000; 137static const u64 kMIPS64_ShadowOffset64 = 1ULL << 37; 138static const u64 kPPC64_ShadowOffset64 = 1ULL << 41; 139static const u64 kSystemZ_ShadowOffset64 = 1ULL << 52; 140static const u64 kFreeBSD_ShadowOffset32 = 1ULL << 30; // 0x40000000 141static const u64 kFreeBSD_ShadowOffset64 = 1ULL << 46; // 0x400000000000 142static const u64 kWindowsShadowOffset32 = 3ULL << 28; // 0x30000000 143static const u64 kWindowsShadowOffset64 = 1ULL << 45; // 32TB 144 145#define SHADOW_SCALE kDefaultShadowScale 146 147 148#if SANITIZER_WORDSIZE == 32 149# if SANITIZER_ANDROID 150# define SHADOW_OFFSET (0) 151# elif defined(__mips__) 152# define SHADOW_OFFSET kMIPS32_ShadowOffset32 153# elif SANITIZER_FREEBSD 154# define SHADOW_OFFSET kFreeBSD_ShadowOffset32 155# elif SANITIZER_WINDOWS 156# define SHADOW_OFFSET kWindowsShadowOffset32 157# elif SANITIZER_IOS 158# if SANITIZER_IOSSIM 159# define SHADOW_OFFSET kIosSimShadowOffset32 160# else 161# define SHADOW_OFFSET kIosShadowOffset32 162# endif 163# else 164# define SHADOW_OFFSET kDefaultShadowOffset32 165# endif 166#else 167# if SANITIZER_IOS 168# if SANITIZER_IOSSIM 169# define SHADOW_OFFSET kIosSimShadowOffset64 170# else 171# define SHADOW_OFFSET kIosShadowOffset64 172# endif 173# elif defined(__aarch64__) 174# define SHADOW_OFFSET kAArch64_ShadowOffset64 175# elif defined(__powerpc64__) 176# define SHADOW_OFFSET kPPC64_ShadowOffset64 177# elif defined(__s390x__) 178# define SHADOW_OFFSET kSystemZ_ShadowOffset64 179# elif SANITIZER_FREEBSD 180# define SHADOW_OFFSET kFreeBSD_ShadowOffset64 181# elif SANITIZER_MAC 182# define SHADOW_OFFSET kDefaultShadowOffset64 183# elif defined(__mips64) 184# define SHADOW_OFFSET kMIPS64_ShadowOffset64 185# elif SANITIZER_WINDOWS64 186# define SHADOW_OFFSET kWindowsShadowOffset64 187# else 188# define SHADOW_OFFSET kDefaultShort64bitShadowOffset 189# endif 190#endif 191 192#define SHADOW_GRANULARITY (1ULL << SHADOW_SCALE) 193#define MEM_TO_SHADOW(mem) (((mem) >> SHADOW_SCALE) + (SHADOW_OFFSET)) 194#define SHADOW_TO_MEM(shadow) (((shadow) - SHADOW_OFFSET) << SHADOW_SCALE) 195 196#define kLowMemBeg 0 197#define kLowMemEnd (SHADOW_OFFSET ? SHADOW_OFFSET - 1 : 0) 198 199#define kLowShadowBeg SHADOW_OFFSET 200#define kLowShadowEnd MEM_TO_SHADOW(kLowMemEnd) 201 202#define kHighMemBeg (MEM_TO_SHADOW(kHighMemEnd) + 1) 203 204#define kHighShadowBeg MEM_TO_SHADOW(kHighMemBeg) 205#define kHighShadowEnd MEM_TO_SHADOW(kHighMemEnd) 206 207# define kMidShadowBeg MEM_TO_SHADOW(kMidMemBeg) 208# define kMidShadowEnd MEM_TO_SHADOW(kMidMemEnd) 209 210// With the zero shadow base we can not actually map pages starting from 0. 211// This constant is somewhat arbitrary. 212#define kZeroBaseShadowStart 0 213#define kZeroBaseMaxShadowStart (1 << 18) 214 215#define kShadowGapBeg (kLowShadowEnd ? kLowShadowEnd + 1 \ 216 : kZeroBaseShadowStart) 217#define kShadowGapEnd ((kMidMemBeg ? kMidShadowBeg : kHighShadowBeg) - 1) 218 219#define kShadowGap2Beg (kMidMemBeg ? kMidShadowEnd + 1 : 0) 220#define kShadowGap2End (kMidMemBeg ? kMidMemBeg - 1 : 0) 221 222#define kShadowGap3Beg (kMidMemBeg ? kMidMemEnd + 1 : 0) 223#define kShadowGap3End (kMidMemBeg ? kHighShadowBeg - 1 : 0) 224 225#define DO_ASAN_MAPPING_PROFILE 0 // Set to 1 to profile the functions below. 226 227#if DO_ASAN_MAPPING_PROFILE 228# define PROFILE_ASAN_MAPPING() AsanMappingProfile[__LINE__]++; 229#else 230# define PROFILE_ASAN_MAPPING() 231#endif 232 233// If 1, all shadow boundaries are constants. 234// Don't set to 1 other than for testing. 235#define ASAN_FIXED_MAPPING 0 236 237namespace __asan { 238 239extern uptr AsanMappingProfile[]; 240 241#if ASAN_FIXED_MAPPING 242// Fixed mapping for 64-bit Linux. Mostly used for performance comparison 243// with non-fixed mapping. As of r175253 (Feb 2013) the performance 244// difference between fixed and non-fixed mapping is below the noise level. 245static uptr kHighMemEnd = 0x7fffffffffffULL; 246static uptr kMidMemBeg = 0x3000000000ULL; 247static uptr kMidMemEnd = 0x4fffffffffULL; 248#else 249extern uptr kHighMemEnd, kMidMemBeg, kMidMemEnd; // Initialized in __asan_init. 250#endif 251 252static inline bool AddrIsInLowMem(uptr a) { 253 PROFILE_ASAN_MAPPING(); 254 return a < kLowMemEnd; 255} 256 257static inline bool AddrIsInLowShadow(uptr a) { 258 PROFILE_ASAN_MAPPING(); 259 return a >= kLowShadowBeg && a <= kLowShadowEnd; 260} 261 262static inline bool AddrIsInHighMem(uptr a) { 263 PROFILE_ASAN_MAPPING(); 264 return a >= kHighMemBeg && a <= kHighMemEnd; 265} 266 267static inline bool AddrIsInMidMem(uptr a) { 268 PROFILE_ASAN_MAPPING(); 269 return kMidMemBeg && a >= kMidMemBeg && a <= kMidMemEnd; 270} 271 272static inline bool AddrIsInMem(uptr a) { 273 PROFILE_ASAN_MAPPING(); 274 return AddrIsInLowMem(a) || AddrIsInMidMem(a) || AddrIsInHighMem(a); 275} 276 277static inline uptr MemToShadow(uptr p) { 278 PROFILE_ASAN_MAPPING(); 279 CHECK(AddrIsInMem(p)); 280 return MEM_TO_SHADOW(p); 281} 282 283static inline bool AddrIsInHighShadow(uptr a) { 284 PROFILE_ASAN_MAPPING(); 285 return a >= kHighShadowBeg && a <= kHighMemEnd; 286} 287 288static inline bool AddrIsInMidShadow(uptr a) { 289 PROFILE_ASAN_MAPPING(); 290 return kMidMemBeg && a >= kMidShadowBeg && a <= kMidMemEnd; 291} 292 293static inline bool AddrIsInShadow(uptr a) { 294 PROFILE_ASAN_MAPPING(); 295 return AddrIsInLowShadow(a) || AddrIsInMidShadow(a) || AddrIsInHighShadow(a); 296} 297 298static inline bool AddrIsInShadowGap(uptr a) { 299 PROFILE_ASAN_MAPPING(); 300 if (kMidMemBeg) { 301 if (a <= kShadowGapEnd) 302 return SHADOW_OFFSET == 0 || a >= kShadowGapBeg; 303 return (a >= kShadowGap2Beg && a <= kShadowGap2End) || 304 (a >= kShadowGap3Beg && a <= kShadowGap3End); 305 } 306 // In zero-based shadow mode we treat addresses near zero as addresses 307 // in shadow gap as well. 308 if (SHADOW_OFFSET == 0) 309 return a <= kShadowGapEnd; 310 return a >= kShadowGapBeg && a <= kShadowGapEnd; 311} 312 313static inline bool AddrIsAlignedByGranularity(uptr a) { 314 PROFILE_ASAN_MAPPING(); 315 return (a & (SHADOW_GRANULARITY - 1)) == 0; 316} 317 318static inline bool AddressIsPoisoned(uptr a) { 319 PROFILE_ASAN_MAPPING(); 320 const uptr kAccessSize = 1; 321 u8 *shadow_address = (u8*)MEM_TO_SHADOW(a); 322 s8 shadow_value = *shadow_address; 323 if (shadow_value) { 324 u8 last_accessed_byte = (a & (SHADOW_GRANULARITY - 1)) 325 + kAccessSize - 1; 326 return (last_accessed_byte >= shadow_value); 327 } 328 return false; 329} 330 331// Must be after all calls to PROFILE_ASAN_MAPPING(). 332static const uptr kAsanMappingProfileSize = __LINE__; 333 334} // namespace __asan 335 336#endif // ASAN_MAPPING_H 337