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 || 126 127 static const u64 kDefaultShadowScale = 3; 128 static const u64 kDefaultShadowOffset32 = 1ULL << 29; // 0x20000000 129 static const u64 kDefaultShadowOffset64 = 1ULL << 44; 130 static const u64 kDefaultShort64bitShadowOffset = 0x7FFF8000; // < 2G. 131 static const u64 kIosShadowOffset32 = 1ULL << 30; // 0x40000000 132 static const u64 kIosShadowOffset64 = 0x120200000; 133 static const u64 kIosSimShadowOffset32 = 1ULL << 30; 134 static const u64 kIosSimShadowOffset64 = kDefaultShadowOffset64; 135 static const u64 kAArch64_ShadowOffset64 = 1ULL << 36; 136 static const u64 kMIPS32_ShadowOffset32 = 0x0aaa0000; 137 static const u64 kMIPS64_ShadowOffset64 = 1ULL << 37; 138 static const u64 kPPC64_ShadowOffset64 = 1ULL << 41; 139 static const u64 kSystemZ_ShadowOffset64 = 1ULL << 52; 140 static const u64 kFreeBSD_ShadowOffset32 = 1ULL << 30; // 0x40000000 141 static const u64 kFreeBSD_ShadowOffset64 = 1ULL << 46; // 0x400000000000 142 static const u64 kWindowsShadowOffset32 = 3ULL << 28; // 0x30000000 143 static 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 0 236 237 namespace __asan { 238 239 extern 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. 245 static uptr kHighMemEnd = 0x7fffffffffffULL; 246 static uptr kMidMemBeg = 0x3000000000ULL; 247 static uptr kMidMemEnd = 0x4fffffffffULL; 248 #else 249 extern uptr kHighMemEnd, kMidMemBeg, kMidMemEnd; // Initialized in __asan_init. 250 #endif 251 252 static inline bool AddrIsInLowMem(uptr a) { 253 PROFILE_ASAN_MAPPING(); 254 return a < kLowMemEnd; 255 } 256 257 static inline bool AddrIsInLowShadow(uptr a) { 258 PROFILE_ASAN_MAPPING(); 259 return a >= kLowShadowBeg && a <= kLowShadowEnd; 260 } 261 262 static inline bool AddrIsInHighMem(uptr a) { 263 PROFILE_ASAN_MAPPING(); 264 return a >= kHighMemBeg && a <= kHighMemEnd; 265 } 266 267 static inline bool AddrIsInMidMem(uptr a) { 268 PROFILE_ASAN_MAPPING(); 269 return kMidMemBeg && a >= kMidMemBeg && a <= kMidMemEnd; 270 } 271 272 static inline bool AddrIsInMem(uptr a) { 273 PROFILE_ASAN_MAPPING(); 274 return AddrIsInLowMem(a) || AddrIsInMidMem(a) || AddrIsInHighMem(a); 275 } 276 277 static inline uptr MemToShadow(uptr p) { 278 PROFILE_ASAN_MAPPING(); 279 CHECK(AddrIsInMem(p)); 280 return MEM_TO_SHADOW(p); 281 } 282 283 static inline bool AddrIsInHighShadow(uptr a) { 284 PROFILE_ASAN_MAPPING(); 285 return a >= kHighShadowBeg && a <= kHighMemEnd; 286 } 287 288 static inline bool AddrIsInMidShadow(uptr a) { 289 PROFILE_ASAN_MAPPING(); 290 return kMidMemBeg && a >= kMidShadowBeg && a <= kMidMemEnd; 291 } 292 293 static inline bool AddrIsInShadow(uptr a) { 294 PROFILE_ASAN_MAPPING(); 295 return AddrIsInLowShadow(a) || AddrIsInMidShadow(a) || AddrIsInHighShadow(a); 296 } 297 298 static 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 } 312 313 static inline bool AddrIsAlignedByGranularity(uptr a) { 314 PROFILE_ASAN_MAPPING(); 315 return (a & (SHADOW_GRANULARITY - 1)) == 0; 316 } 317 318 static 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(). 332 static const uptr kAsanMappingProfileSize = __LINE__; 333 334 } // namespace __asan 335 336 #endif // ASAN_MAPPING_H 337
