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 // Shadow mapping on FreeBSD/x86-64 with SHADOW_OFFSET == 0x400000000000: 91 // || `[0x500000000000, 0x7fffffffffff]` || HighMem || 92 // || `[0x4a0000000000, 0x4fffffffffff]` || HighShadow || 93 // || `[0x480000000000, 0x49ffffffffff]` || ShadowGap || 94 // || `[0x400000000000, 0x47ffffffffff]` || LowShadow || 95 // || `[0x000000000000, 0x3fffffffffff]` || LowMem || 96 // 97 // Shadow mapping on FreeBSD/i386 with SHADOW_OFFSET == 0x40000000: 98 // || `[0x60000000, 0xffffffff]` || HighMem || 99 // || `[0x4c000000, 0x5fffffff]` || HighShadow || 100 // || `[0x48000000, 0x4bffffff]` || ShadowGap || 101 // || `[0x40000000, 0x47ffffff]` || LowShadow || 102 // || `[0x00000000, 0x3fffffff]` || LowMem || 103 // 104 // Default Windows/i386 mapping: 105 // (the exact location of HighShadow/HighMem may vary depending 106 // on WoW64, /LARGEADDRESSAWARE, etc). 107 // || `[0x50000000, 0xffffffff]` || HighMem || 108 // || `[0x3a000000, 0x4fffffff]` || HighShadow || 109 // || `[0x36000000, 0x39ffffff]` || ShadowGap || 110 // || `[0x30000000, 0x35ffffff]` || LowShadow || 111 // || `[0x00000000, 0x2fffffff]` || LowMem || 112 113 static const u64 kDefaultShadowScale = 3; 114 static const u64 kDefaultShadowOffset32 = 1ULL << 29; // 0x20000000 115 static const u64 kDefaultShadowOffset64 = 1ULL << 44; 116 static const u64 kDefaultShort64bitShadowOffset = 0x7FFF8000; // < 2G. 117 static const u64 kIosShadowOffset32 = 1ULL << 30; // 0x40000000 118 static const u64 kIosShadowOffset64 = 0x130000000; 119 static const u64 kIosSimShadowOffset32 = 1ULL << 30; 120 static const u64 kIosSimShadowOffset64 = kDefaultShadowOffset64; 121 static const u64 kAArch64_ShadowOffset64 = 1ULL << 36; 122 static const u64 kMIPS32_ShadowOffset32 = 0x0aaa0000; 123 static const u64 kMIPS64_ShadowOffset64 = 1ULL << 37; 124 static const u64 kPPC64_ShadowOffset64 = 1ULL << 41; 125 static const u64 kFreeBSD_ShadowOffset32 = 1ULL << 30; // 0x40000000 126 static const u64 kFreeBSD_ShadowOffset64 = 1ULL << 46; // 0x400000000000 127 static const u64 kWindowsShadowOffset32 = 3ULL << 28; // 0x30000000 128 129 #define SHADOW_SCALE kDefaultShadowScale 130 131 132 #if SANITIZER_WORDSIZE == 32 133 # if SANITIZER_ANDROID 134 # define SHADOW_OFFSET (0) 135 # elif defined(__mips__) 136 # define SHADOW_OFFSET kMIPS32_ShadowOffset32 137 # elif SANITIZER_FREEBSD 138 # define SHADOW_OFFSET kFreeBSD_ShadowOffset32 139 # elif SANITIZER_WINDOWS 140 # define SHADOW_OFFSET kWindowsShadowOffset32 141 # elif SANITIZER_IOSSIM 142 # define SHADOW_OFFSET kIosSimShadowOffset32 143 # elif SANITIZER_IOS 144 # define SHADOW_OFFSET kIosShadowOffset32 145 # else 146 # define SHADOW_OFFSET kDefaultShadowOffset32 147 # endif 148 #else 149 # if defined(__aarch64__) 150 # define SHADOW_OFFSET kAArch64_ShadowOffset64 151 # elif defined(__powerpc64__) 152 # define SHADOW_OFFSET kPPC64_ShadowOffset64 153 # elif SANITIZER_FREEBSD 154 # define SHADOW_OFFSET kFreeBSD_ShadowOffset64 155 # elif SANITIZER_MAC 156 # define SHADOW_OFFSET kDefaultShadowOffset64 157 # elif defined(__mips64) 158 # define SHADOW_OFFSET kMIPS64_ShadowOffset64 159 # elif SANITIZER_IOSSIM 160 # define SHADOW_OFFSET kIosSimShadowOffset64 161 # elif SANITIZER_IOS 162 # define SHADOW_OFFSET kIosShadowOffset64 163 # else 164 # define SHADOW_OFFSET kDefaultShort64bitShadowOffset 165 # endif 166 #endif 167 168 #define SHADOW_GRANULARITY (1ULL << SHADOW_SCALE) 169 #define MEM_TO_SHADOW(mem) (((mem) >> SHADOW_SCALE) + (SHADOW_OFFSET)) 170 #define SHADOW_TO_MEM(shadow) (((shadow) - SHADOW_OFFSET) << SHADOW_SCALE) 171 172 #define kLowMemBeg 0 173 #define kLowMemEnd (SHADOW_OFFSET ? SHADOW_OFFSET - 1 : 0) 174 175 #define kLowShadowBeg SHADOW_OFFSET 176 #define kLowShadowEnd MEM_TO_SHADOW(kLowMemEnd) 177 178 #define kHighMemBeg (MEM_TO_SHADOW(kHighMemEnd) + 1) 179 180 #define kHighShadowBeg MEM_TO_SHADOW(kHighMemBeg) 181 #define kHighShadowEnd MEM_TO_SHADOW(kHighMemEnd) 182 183 # define kMidShadowBeg MEM_TO_SHADOW(kMidMemBeg) 184 # define kMidShadowEnd MEM_TO_SHADOW(kMidMemEnd) 185 186 // With the zero shadow base we can not actually map pages starting from 0. 187 // This constant is somewhat arbitrary. 188 #define kZeroBaseShadowStart 0 189 #define kZeroBaseMaxShadowStart (1 << 18) 190 191 #define kShadowGapBeg (kLowShadowEnd ? kLowShadowEnd + 1 \ 192 : kZeroBaseShadowStart) 193 #define kShadowGapEnd ((kMidMemBeg ? kMidShadowBeg : kHighShadowBeg) - 1) 194 195 #define kShadowGap2Beg (kMidMemBeg ? kMidShadowEnd + 1 : 0) 196 #define kShadowGap2End (kMidMemBeg ? kMidMemBeg - 1 : 0) 197 198 #define kShadowGap3Beg (kMidMemBeg ? kMidMemEnd + 1 : 0) 199 #define kShadowGap3End (kMidMemBeg ? kHighShadowBeg - 1 : 0) 200 201 #define DO_ASAN_MAPPING_PROFILE 0 // Set to 1 to profile the functions below. 202 203 #if DO_ASAN_MAPPING_PROFILE 204 # define PROFILE_ASAN_MAPPING() AsanMappingProfile[__LINE__]++; 205 #else 206 # define PROFILE_ASAN_MAPPING() 207 #endif 208 209 // If 1, all shadow boundaries are constants. 210 // Don't set to 1 other than for testing. 211 #define ASAN_FIXED_MAPPING 0 212 213 namespace __asan { 214 215 extern uptr AsanMappingProfile[]; 216 217 #if ASAN_FIXED_MAPPING 218 // Fixed mapping for 64-bit Linux. Mostly used for performance comparison 219 // with non-fixed mapping. As of r175253 (Feb 2013) the performance 220 // difference between fixed and non-fixed mapping is below the noise level. 221 static uptr kHighMemEnd = 0x7fffffffffffULL; 222 static uptr kMidMemBeg = 0x3000000000ULL; 223 static uptr kMidMemEnd = 0x4fffffffffULL; 224 #else 225 extern uptr kHighMemEnd, kMidMemBeg, kMidMemEnd; // Initialized in __asan_init. 226 #endif 227 228 static inline bool AddrIsInLowMem(uptr a) { 229 PROFILE_ASAN_MAPPING(); 230 return a < kLowMemEnd; 231 } 232 233 static inline bool AddrIsInLowShadow(uptr a) { 234 PROFILE_ASAN_MAPPING(); 235 return a >= kLowShadowBeg && a <= kLowShadowEnd; 236 } 237 238 static inline bool AddrIsInHighMem(uptr a) { 239 PROFILE_ASAN_MAPPING(); 240 return a >= kHighMemBeg && a <= kHighMemEnd; 241 } 242 243 static inline bool AddrIsInMidMem(uptr a) { 244 PROFILE_ASAN_MAPPING(); 245 return kMidMemBeg && a >= kMidMemBeg && a <= kMidMemEnd; 246 } 247 248 static inline bool AddrIsInMem(uptr a) { 249 PROFILE_ASAN_MAPPING(); 250 return AddrIsInLowMem(a) || AddrIsInMidMem(a) || AddrIsInHighMem(a); 251 } 252 253 static inline uptr MemToShadow(uptr p) { 254 PROFILE_ASAN_MAPPING(); 255 CHECK(AddrIsInMem(p)); 256 return MEM_TO_SHADOW(p); 257 } 258 259 static inline bool AddrIsInHighShadow(uptr a) { 260 PROFILE_ASAN_MAPPING(); 261 return a >= kHighShadowBeg && a <= kHighMemEnd; 262 } 263 264 static inline bool AddrIsInMidShadow(uptr a) { 265 PROFILE_ASAN_MAPPING(); 266 return kMidMemBeg && a >= kMidShadowBeg && a <= kMidMemEnd; 267 } 268 269 static inline bool AddrIsInShadow(uptr a) { 270 PROFILE_ASAN_MAPPING(); 271 return AddrIsInLowShadow(a) || AddrIsInMidShadow(a) || AddrIsInHighShadow(a); 272 } 273 274 static inline bool AddrIsInShadowGap(uptr a) { 275 PROFILE_ASAN_MAPPING(); 276 if (kMidMemBeg) { 277 if (a <= kShadowGapEnd) 278 return SHADOW_OFFSET == 0 || a >= kShadowGapBeg; 279 return (a >= kShadowGap2Beg && a <= kShadowGap2End) || 280 (a >= kShadowGap3Beg && a <= kShadowGap3End); 281 } 282 // In zero-based shadow mode we treat addresses near zero as addresses 283 // in shadow gap as well. 284 if (SHADOW_OFFSET == 0) 285 return a <= kShadowGapEnd; 286 return a >= kShadowGapBeg && a <= kShadowGapEnd; 287 } 288 289 static inline bool AddrIsAlignedByGranularity(uptr a) { 290 PROFILE_ASAN_MAPPING(); 291 return (a & (SHADOW_GRANULARITY - 1)) == 0; 292 } 293 294 static inline bool AddressIsPoisoned(uptr a) { 295 PROFILE_ASAN_MAPPING(); 296 const uptr kAccessSize = 1; 297 u8 *shadow_address = (u8*)MEM_TO_SHADOW(a); 298 s8 shadow_value = *shadow_address; 299 if (shadow_value) { 300 u8 last_accessed_byte = (a & (SHADOW_GRANULARITY - 1)) 301 + kAccessSize - 1; 302 return (last_accessed_byte >= shadow_value); 303 } 304 return false; 305 } 306 307 // Must be after all calls to PROFILE_ASAN_MAPPING(). 308 static const uptr kAsanMappingProfileSize = __LINE__; 309 310 } // namespace __asan 311 312 #endif // ASAN_MAPPING_H 313
