1229109Sed//===-- asan_mapping.h ------------------------------------------*- C++ -*-===// 2229109Sed// 3229109Sed// The LLVM Compiler Infrastructure 4229109Sed// 5229109Sed// This file is distributed under the University of Illinois Open Source 6229109Sed// License. See LICENSE.TXT for details. 7229109Sed// 8229109Sed//===----------------------------------------------------------------------===// 9229109Sed// 10229109Sed// This file is a part of AddressSanitizer, an address sanity checker. 11229109Sed// 12229109Sed// Defines ASan memory mapping. 13229109Sed//===----------------------------------------------------------------------===// 14229109Sed#ifndef ASAN_MAPPING_H 15229109Sed#define ASAN_MAPPING_H 16229109Sed 17229109Sed#include "asan_internal.h" 18229109Sed 19229109Sed// The full explanation of the memory mapping could be found here: 20296417Sdim// https://github.com/google/sanitizers/wiki/AddressSanitizerAlgorithm 21251034Sed// 22251034Sed// Typical shadow mapping on Linux/x86_64 with SHADOW_OFFSET == 0x00007fff8000: 23251034Sed// || `[0x10007fff8000, 0x7fffffffffff]` || HighMem || 24251034Sed// || `[0x02008fff7000, 0x10007fff7fff]` || HighShadow || 25251034Sed// || `[0x00008fff7000, 0x02008fff6fff]` || ShadowGap || 26251034Sed// || `[0x00007fff8000, 0x00008fff6fff]` || LowShadow || 27251034Sed// || `[0x000000000000, 0x00007fff7fff]` || LowMem || 28251034Sed// 29251034Sed// When SHADOW_OFFSET is zero (-pie): 30251034Sed// || `[0x100000000000, 0x7fffffffffff]` || HighMem || 31251034Sed// || `[0x020000000000, 0x0fffffffffff]` || HighShadow || 32251034Sed// || `[0x000000040000, 0x01ffffffffff]` || ShadowGap || 33251034Sed// 34251034Sed// Special case when something is already mapped between 35251034Sed// 0x003000000000 and 0x005000000000 (e.g. when prelink is installed): 36251034Sed// || `[0x10007fff8000, 0x7fffffffffff]` || HighMem || 37251034Sed// || `[0x02008fff7000, 0x10007fff7fff]` || HighShadow || 38251034Sed// || `[0x005000000000, 0x02008fff6fff]` || ShadowGap3 || 39251034Sed// || `[0x003000000000, 0x004fffffffff]` || MidMem || 40251034Sed// || `[0x000a7fff8000, 0x002fffffffff]` || ShadowGap2 || 41251034Sed// || `[0x00067fff8000, 0x000a7fff7fff]` || MidShadow || 42251034Sed// || `[0x00008fff7000, 0x00067fff7fff]` || ShadowGap || 43251034Sed// || `[0x00007fff8000, 0x00008fff6fff]` || LowShadow || 44251034Sed// || `[0x000000000000, 0x00007fff7fff]` || LowMem || 45251034Sed// 46276789Sdim// Default Linux/i386 mapping on x86_64 machine: 47251034Sed// || `[0x40000000, 0xffffffff]` || HighMem || 48251034Sed// || `[0x28000000, 0x3fffffff]` || HighShadow || 49251034Sed// || `[0x24000000, 0x27ffffff]` || ShadowGap || 50251034Sed// || `[0x20000000, 0x23ffffff]` || LowShadow || 51251034Sed// || `[0x00000000, 0x1fffffff]` || LowMem || 52274201Sdim// 53276789Sdim// Default Linux/i386 mapping on i386 machine 54276789Sdim// (addresses starting with 0xc0000000 are reserved 55276789Sdim// for kernel and thus not sanitized): 56276789Sdim// || `[0x38000000, 0xbfffffff]` || HighMem || 57276789Sdim// || `[0x27000000, 0x37ffffff]` || HighShadow || 58276789Sdim// || `[0x24000000, 0x26ffffff]` || ShadowGap || 59276789Sdim// || `[0x20000000, 0x23ffffff]` || LowShadow || 60276789Sdim// || `[0x00000000, 0x1fffffff]` || LowMem || 61276789Sdim// 62280031Sdim// Default Linux/MIPS32 mapping: 63276789Sdim// || `[0x2aaa0000, 0xffffffff]` || HighMem || 64276789Sdim// || `[0x0fff4000, 0x2aa9ffff]` || HighShadow || 65276789Sdim// || `[0x0bff4000, 0x0fff3fff]` || ShadowGap || 66276789Sdim// || `[0x0aaa0000, 0x0bff3fff]` || LowShadow || 67276789Sdim// || `[0x00000000, 0x0aa9ffff]` || LowMem || 68276789Sdim// 69280031Sdim// Default Linux/MIPS64 mapping: 70280031Sdim// || `[0x4000000000, 0xffffffffff]` || HighMem || 71280031Sdim// || `[0x2800000000, 0x3fffffffff]` || HighShadow || 72280031Sdim// || `[0x2400000000, 0x27ffffffff]` || ShadowGap || 73280031Sdim// || `[0x2000000000, 0x23ffffffff]` || LowShadow || 74280031Sdim// || `[0x0000000000, 0x1fffffffff]` || LowMem || 75280031Sdim// 76296417Sdim// Default Linux/AArch64 (39-bit VMA) mapping: 77296417Sdim// || `[0x2000000000, 0x7fffffffff]` || highmem || 78296417Sdim// || `[0x1400000000, 0x1fffffffff]` || highshadow || 79296417Sdim// || `[0x1200000000, 0x13ffffffff]` || shadowgap || 80296417Sdim// || `[0x1000000000, 0x11ffffffff]` || lowshadow || 81296417Sdim// || `[0x0000000000, 0x0fffffffff]` || lowmem || 82296417Sdim// 83296417Sdim// Default Linux/AArch64 (42-bit VMA) mapping: 84296417Sdim// || `[0x10000000000, 0x3ffffffffff]` || highmem || 85296417Sdim// || `[0x0a000000000, 0x0ffffffffff]` || highshadow || 86296417Sdim// || `[0x09000000000, 0x09fffffffff]` || shadowgap || 87296417Sdim// || `[0x08000000000, 0x08fffffffff]` || lowshadow || 88296417Sdim// || `[0x00000000000, 0x07fffffffff]` || lowmem || 89296417Sdim// 90276789Sdim// Shadow mapping on FreeBSD/x86-64 with SHADOW_OFFSET == 0x400000000000: 91276789Sdim// || `[0x500000000000, 0x7fffffffffff]` || HighMem || 92276789Sdim// || `[0x4a0000000000, 0x4fffffffffff]` || HighShadow || 93276789Sdim// || `[0x480000000000, 0x49ffffffffff]` || ShadowGap || 94276789Sdim// || `[0x400000000000, 0x47ffffffffff]` || LowShadow || 95276789Sdim// || `[0x000000000000, 0x3fffffffffff]` || LowMem || 96276789Sdim// 97276789Sdim// Shadow mapping on FreeBSD/i386 with SHADOW_OFFSET == 0x40000000: 98276789Sdim// || `[0x60000000, 0xffffffff]` || HighMem || 99276789Sdim// || `[0x4c000000, 0x5fffffff]` || HighShadow || 100276789Sdim// || `[0x48000000, 0x4bffffff]` || ShadowGap || 101276789Sdim// || `[0x40000000, 0x47ffffff]` || LowShadow || 102276789Sdim// || `[0x00000000, 0x3fffffff]` || LowMem || 103280031Sdim// 104280031Sdim// Default Windows/i386 mapping: 105280031Sdim// (the exact location of HighShadow/HighMem may vary depending 106280031Sdim// on WoW64, /LARGEADDRESSAWARE, etc). 107280031Sdim// || `[0x50000000, 0xffffffff]` || HighMem || 108280031Sdim// || `[0x3a000000, 0x4fffffff]` || HighShadow || 109280031Sdim// || `[0x36000000, 0x39ffffff]` || ShadowGap || 110280031Sdim// || `[0x30000000, 0x35ffffff]` || LowShadow || 111280031Sdim// || `[0x00000000, 0x2fffffff]` || LowMem || 112229109Sed 113274201Sdimstatic const u64 kDefaultShadowScale = 3; 114276789Sdimstatic const u64 kDefaultShadowOffset32 = 1ULL << 29; // 0x20000000 115274201Sdimstatic const u64 kDefaultShadowOffset64 = 1ULL << 44; 116274201Sdimstatic const u64 kDefaultShort64bitShadowOffset = 0x7FFF8000; // < 2G. 117288943Sdimstatic const u64 kIosShadowOffset32 = 1ULL << 30; // 0x40000000 118288943Sdimstatic const u64 kIosShadowOffset64 = 0x130000000; 119288943Sdimstatic const u64 kIosSimShadowOffset32 = 1ULL << 30; 120288943Sdimstatic const u64 kIosSimShadowOffset64 = kDefaultShadowOffset64; 121276789Sdimstatic const u64 kAArch64_ShadowOffset64 = 1ULL << 36; 122276789Sdimstatic const u64 kMIPS32_ShadowOffset32 = 0x0aaa0000; 123280031Sdimstatic const u64 kMIPS64_ShadowOffset64 = 1ULL << 37; 124274201Sdimstatic const u64 kPPC64_ShadowOffset64 = 1ULL << 41; 125276789Sdimstatic const u64 kFreeBSD_ShadowOffset32 = 1ULL << 30; // 0x40000000 126276789Sdimstatic const u64 kFreeBSD_ShadowOffset64 = 1ULL << 46; // 0x400000000000 127280031Sdimstatic const u64 kWindowsShadowOffset32 = 3ULL << 28; // 0x30000000 128274201Sdim 129276789Sdim#define SHADOW_SCALE kDefaultShadowScale 130296417Sdim 131296417Sdim 132296417Sdim#if SANITIZER_WORDSIZE == 32 133296417Sdim# if SANITIZER_ANDROID 134296417Sdim# define SHADOW_OFFSET (0) 135296417Sdim# elif defined(__mips__) 136276789Sdim# define SHADOW_OFFSET kMIPS32_ShadowOffset32 137276789Sdim# elif SANITIZER_FREEBSD 138276789Sdim# define SHADOW_OFFSET kFreeBSD_ShadowOffset32 139288943Sdim# elif SANITIZER_WINDOWS 140288943Sdim# define SHADOW_OFFSET kWindowsShadowOffset32 141288943Sdim# elif SANITIZER_IOSSIM 142288943Sdim# define SHADOW_OFFSET kIosSimShadowOffset32 143280031Sdim# elif SANITIZER_IOS 144280031Sdim# define SHADOW_OFFSET kIosShadowOffset32 145276789Sdim# else 146280031Sdim# define SHADOW_OFFSET kDefaultShadowOffset32 147276789Sdim# endif 148296417Sdim#else 149276789Sdim# if defined(__aarch64__) 150276789Sdim# define SHADOW_OFFSET kAArch64_ShadowOffset64 151276789Sdim# elif defined(__powerpc64__) 152276789Sdim# define SHADOW_OFFSET kPPC64_ShadowOffset64 153276789Sdim# elif SANITIZER_FREEBSD 154276789Sdim# define SHADOW_OFFSET kFreeBSD_ShadowOffset64 155276789Sdim# elif SANITIZER_MAC 156276789Sdim# define SHADOW_OFFSET kDefaultShadowOffset64 157276789Sdim# elif defined(__mips64) 158276789Sdim# define SHADOW_OFFSET kMIPS64_ShadowOffset64 159288943Sdim# elif SANITIZER_IOSSIM 160288943Sdim# define SHADOW_OFFSET kIosSimShadowOffset64 161288943Sdim# elif SANITIZER_IOS 162288943Sdim# define SHADOW_OFFSET kIosShadowOffset64 163238901Sandrew# else 164276789Sdim# define SHADOW_OFFSET kDefaultShort64bitShadowOffset 165238901Sandrew# endif 166276789Sdim#endif 167229109Sed 168229109Sed#define SHADOW_GRANULARITY (1ULL << SHADOW_SCALE) 169251034Sed#define MEM_TO_SHADOW(mem) (((mem) >> SHADOW_SCALE) + (SHADOW_OFFSET)) 170238901Sandrew#define SHADOW_TO_MEM(shadow) (((shadow) - SHADOW_OFFSET) << SHADOW_SCALE) 171229109Sed 172229109Sed#define kLowMemBeg 0 173229109Sed#define kLowMemEnd (SHADOW_OFFSET ? SHADOW_OFFSET - 1 : 0) 174229109Sed 175229109Sed#define kLowShadowBeg SHADOW_OFFSET 176229109Sed#define kLowShadowEnd MEM_TO_SHADOW(kLowMemEnd) 177229109Sed 178229109Sed#define kHighMemBeg (MEM_TO_SHADOW(kHighMemEnd) + 1) 179229109Sed 180229109Sed#define kHighShadowBeg MEM_TO_SHADOW(kHighMemBeg) 181229109Sed#define kHighShadowEnd MEM_TO_SHADOW(kHighMemEnd) 182229109Sed 183251034Sed# define kMidShadowBeg MEM_TO_SHADOW(kMidMemBeg) 184251034Sed# define kMidShadowEnd MEM_TO_SHADOW(kMidMemEnd) 185251034Sed 186245614Sandrew// With the zero shadow base we can not actually map pages starting from 0. 187245614Sandrew// This constant is somewhat arbitrary. 188296417Sdim#define kZeroBaseShadowStart 0 189296417Sdim#define kZeroBaseMaxShadowStart (1 << 18) 190245614Sandrew 191245614Sandrew#define kShadowGapBeg (kLowShadowEnd ? kLowShadowEnd + 1 \ 192245614Sandrew : kZeroBaseShadowStart) 193251034Sed#define kShadowGapEnd ((kMidMemBeg ? kMidShadowBeg : kHighShadowBeg) - 1) 194229109Sed 195251034Sed#define kShadowGap2Beg (kMidMemBeg ? kMidShadowEnd + 1 : 0) 196251034Sed#define kShadowGap2End (kMidMemBeg ? kMidMemBeg - 1 : 0) 197229109Sed 198251034Sed#define kShadowGap3Beg (kMidMemBeg ? kMidMemEnd + 1 : 0) 199251034Sed#define kShadowGap3End (kMidMemBeg ? kHighShadowBeg - 1 : 0) 200251034Sed 201251034Sed#define DO_ASAN_MAPPING_PROFILE 0 // Set to 1 to profile the functions below. 202251034Sed 203251034Sed#if DO_ASAN_MAPPING_PROFILE 204251034Sed# define PROFILE_ASAN_MAPPING() AsanMappingProfile[__LINE__]++; 205251034Sed#else 206251034Sed# define PROFILE_ASAN_MAPPING() 207251034Sed#endif 208251034Sed 209251034Sed// If 1, all shadow boundaries are constants. 210251034Sed// Don't set to 1 other than for testing. 211251034Sed#define ASAN_FIXED_MAPPING 0 212251034Sed 213229109Sednamespace __asan { 214229109Sed 215251034Sedextern uptr AsanMappingProfile[]; 216251034Sed 217251034Sed#if ASAN_FIXED_MAPPING 218251034Sed// Fixed mapping for 64-bit Linux. Mostly used for performance comparison 219251034Sed// with non-fixed mapping. As of r175253 (Feb 2013) the performance 220251034Sed// difference between fixed and non-fixed mapping is below the noise level. 221251034Sedstatic uptr kHighMemEnd = 0x7fffffffffffULL; 222251034Sedstatic uptr kMidMemBeg = 0x3000000000ULL; 223251034Sedstatic uptr kMidMemEnd = 0x4fffffffffULL; 224251034Sed#else 225251034Sedextern uptr kHighMemEnd, kMidMemBeg, kMidMemEnd; // Initialized in __asan_init. 226251034Sed#endif 227251034Sed 228238901Sandrewstatic inline bool AddrIsInLowMem(uptr a) { 229251034Sed PROFILE_ASAN_MAPPING(); 230229109Sed return a < kLowMemEnd; 231229109Sed} 232229109Sed 233238901Sandrewstatic inline bool AddrIsInLowShadow(uptr a) { 234251034Sed PROFILE_ASAN_MAPPING(); 235229109Sed return a >= kLowShadowBeg && a <= kLowShadowEnd; 236229109Sed} 237229109Sed 238238901Sandrewstatic inline bool AddrIsInHighMem(uptr a) { 239251034Sed PROFILE_ASAN_MAPPING(); 240229109Sed return a >= kHighMemBeg && a <= kHighMemEnd; 241229109Sed} 242229109Sed 243251034Sedstatic inline bool AddrIsInMidMem(uptr a) { 244251034Sed PROFILE_ASAN_MAPPING(); 245251034Sed return kMidMemBeg && a >= kMidMemBeg && a <= kMidMemEnd; 246251034Sed} 247251034Sed 248238901Sandrewstatic inline bool AddrIsInMem(uptr a) { 249251034Sed PROFILE_ASAN_MAPPING(); 250251034Sed return AddrIsInLowMem(a) || AddrIsInMidMem(a) || AddrIsInHighMem(a); 251229109Sed} 252229109Sed 253238901Sandrewstatic inline uptr MemToShadow(uptr p) { 254251034Sed PROFILE_ASAN_MAPPING(); 255229109Sed CHECK(AddrIsInMem(p)); 256229109Sed return MEM_TO_SHADOW(p); 257229109Sed} 258229109Sed 259238901Sandrewstatic inline bool AddrIsInHighShadow(uptr a) { 260251034Sed PROFILE_ASAN_MAPPING(); 261251034Sed return a >= kHighShadowBeg && a <= kHighMemEnd; 262229109Sed} 263229109Sed 264251034Sedstatic inline bool AddrIsInMidShadow(uptr a) { 265251034Sed PROFILE_ASAN_MAPPING(); 266251034Sed return kMidMemBeg && a >= kMidShadowBeg && a <= kMidMemEnd; 267251034Sed} 268251034Sed 269238901Sandrewstatic inline bool AddrIsInShadow(uptr a) { 270251034Sed PROFILE_ASAN_MAPPING(); 271251034Sed return AddrIsInLowShadow(a) || AddrIsInMidShadow(a) || AddrIsInHighShadow(a); 272229109Sed} 273229109Sed 274238901Sandrewstatic inline bool AddrIsInShadowGap(uptr a) { 275251034Sed PROFILE_ASAN_MAPPING(); 276251034Sed if (kMidMemBeg) { 277251034Sed if (a <= kShadowGapEnd) 278251034Sed return SHADOW_OFFSET == 0 || a >= kShadowGapBeg; 279251034Sed return (a >= kShadowGap2Beg && a <= kShadowGap2End) || 280251034Sed (a >= kShadowGap3Beg && a <= kShadowGap3End); 281251034Sed } 282251034Sed // In zero-based shadow mode we treat addresses near zero as addresses 283251034Sed // in shadow gap as well. 284251034Sed if (SHADOW_OFFSET == 0) 285251034Sed return a <= kShadowGapEnd; 286238901Sandrew return a >= kShadowGapBeg && a <= kShadowGapEnd; 287238901Sandrew} 288238901Sandrew 289238901Sandrewstatic inline bool AddrIsAlignedByGranularity(uptr a) { 290251034Sed PROFILE_ASAN_MAPPING(); 291229109Sed return (a & (SHADOW_GRANULARITY - 1)) == 0; 292229109Sed} 293229109Sed 294238901Sandrewstatic inline bool AddressIsPoisoned(uptr a) { 295251034Sed PROFILE_ASAN_MAPPING(); 296238901Sandrew const uptr kAccessSize = 1; 297251034Sed u8 *shadow_address = (u8*)MEM_TO_SHADOW(a); 298238901Sandrew s8 shadow_value = *shadow_address; 299238901Sandrew if (shadow_value) { 300238901Sandrew u8 last_accessed_byte = (a & (SHADOW_GRANULARITY - 1)) 301238901Sandrew + kAccessSize - 1; 302238901Sandrew return (last_accessed_byte >= shadow_value); 303238901Sandrew } 304238901Sandrew return false; 305238901Sandrew} 306238901Sandrew 307251034Sed// Must be after all calls to PROFILE_ASAN_MAPPING(). 308251034Sedstatic const uptr kAsanMappingProfileSize = __LINE__; 309251034Sed 310229109Sed} // namespace __asan 311229109Sed 312229109Sed#endif // ASAN_MAPPING_H 313