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 113static const u64 kDefaultShadowScale = 3; 114static const u64 kDefaultShadowOffset32 = 1ULL << 29; // 0x20000000 115static const u64 kDefaultShadowOffset64 = 1ULL << 44; 116static const u64 kDefaultShort64bitShadowOffset = 0x7FFF8000; // < 2G. 117static const u64 kIosShadowOffset32 = 1ULL << 30; // 0x40000000 118static const u64 kIosShadowOffset64 = 0x130000000; 119static const u64 kIosSimShadowOffset32 = 1ULL << 30; 120static const u64 kIosSimShadowOffset64 = kDefaultShadowOffset64; 121static const u64 kAArch64_ShadowOffset64 = 1ULL << 36; 122static const u64 kMIPS32_ShadowOffset32 = 0x0aaa0000; 123static const u64 kMIPS64_ShadowOffset64 = 1ULL << 37; 124static const u64 kPPC64_ShadowOffset64 = 1ULL << 41; 125static const u64 kFreeBSD_ShadowOffset32 = 1ULL << 30; // 0x40000000 126static const u64 kFreeBSD_ShadowOffset64 = 1ULL << 46; // 0x400000000000 127static 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 213namespace __asan { 214 215extern 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. 221static uptr kHighMemEnd = 0x7fffffffffffULL; 222static uptr kMidMemBeg = 0x3000000000ULL; 223static uptr kMidMemEnd = 0x4fffffffffULL; 224#else 225extern uptr kHighMemEnd, kMidMemBeg, kMidMemEnd; // Initialized in __asan_init. 226#endif 227 228static inline bool AddrIsInLowMem(uptr a) { 229 PROFILE_ASAN_MAPPING(); 230 return a < kLowMemEnd; 231} 232 233static inline bool AddrIsInLowShadow(uptr a) { 234 PROFILE_ASAN_MAPPING(); 235 return a >= kLowShadowBeg && a <= kLowShadowEnd; 236} 237 238static inline bool AddrIsInHighMem(uptr a) { 239 PROFILE_ASAN_MAPPING(); 240 return a >= kHighMemBeg && a <= kHighMemEnd; 241} 242 243static inline bool AddrIsInMidMem(uptr a) { 244 PROFILE_ASAN_MAPPING(); 245 return kMidMemBeg && a >= kMidMemBeg && a <= kMidMemEnd; 246} 247 248static inline bool AddrIsInMem(uptr a) { 249 PROFILE_ASAN_MAPPING(); 250 return AddrIsInLowMem(a) || AddrIsInMidMem(a) || AddrIsInHighMem(a); 251} 252 253static inline uptr MemToShadow(uptr p) { 254 PROFILE_ASAN_MAPPING(); 255 CHECK(AddrIsInMem(p)); 256 return MEM_TO_SHADOW(p); 257} 258 259static inline bool AddrIsInHighShadow(uptr a) { 260 PROFILE_ASAN_MAPPING(); 261 return a >= kHighShadowBeg && a <= kHighMemEnd; 262} 263 264static inline bool AddrIsInMidShadow(uptr a) { 265 PROFILE_ASAN_MAPPING(); 266 return kMidMemBeg && a >= kMidShadowBeg && a <= kMidMemEnd; 267} 268 269static inline bool AddrIsInShadow(uptr a) { 270 PROFILE_ASAN_MAPPING(); 271 return AddrIsInLowShadow(a) || AddrIsInMidShadow(a) || AddrIsInHighShadow(a); 272} 273 274static 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 289static inline bool AddrIsAlignedByGranularity(uptr a) { 290 PROFILE_ASAN_MAPPING(); 291 return (a & (SHADOW_GRANULARITY - 1)) == 0; 292} 293 294static 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(). 308static const uptr kAsanMappingProfileSize = __LINE__; 309 310} // namespace __asan 311 312#endif // ASAN_MAPPING_H 313