asan_mapping.h revision 1.4
1//===-- asan_mapping.h ------------------------------------------*- C++ -*-===// 2// 3// This file is distributed under the University of Illinois Open Source 4// License. See LICENSE.TXT for details. 5// 6//===----------------------------------------------------------------------===// 7// 8// This file is a part of AddressSanitizer, an address sanity checker. 9// 10// Defines ASan memory mapping. 11//===----------------------------------------------------------------------===// 12#ifndef ASAN_MAPPING_H 13#define ASAN_MAPPING_H 14 15#include "asan_internal.h" 16 17// The full explanation of the memory mapping could be found here: 18// http://code.google.com/p/address-sanitizer/wiki/AddressSanitizerAlgorithm 19// 20// Typical shadow mapping on Linux/x86_64 with SHADOW_OFFSET == 0x00007fff8000: 21// || `[0x10007fff8000, 0x7fffffffffff]` || HighMem || 22// || `[0x02008fff7000, 0x10007fff7fff]` || HighShadow || 23// || `[0x00008fff7000, 0x02008fff6fff]` || ShadowGap || 24// || `[0x00007fff8000, 0x00008fff6fff]` || LowShadow || 25// || `[0x000000000000, 0x00007fff7fff]` || LowMem || 26// 27// When SHADOW_OFFSET is zero (-pie): 28// || `[0x100000000000, 0x7fffffffffff]` || HighMem || 29// || `[0x020000000000, 0x0fffffffffff]` || HighShadow || 30// || `[0x000000040000, 0x01ffffffffff]` || ShadowGap || 31// 32// Special case when something is already mapped between 33// 0x003000000000 and 0x005000000000 (e.g. when prelink is installed): 34// || `[0x10007fff8000, 0x7fffffffffff]` || HighMem || 35// || `[0x02008fff7000, 0x10007fff7fff]` || HighShadow || 36// || `[0x005000000000, 0x02008fff6fff]` || ShadowGap3 || 37// || `[0x003000000000, 0x004fffffffff]` || MidMem || 38// || `[0x000a7fff8000, 0x002fffffffff]` || ShadowGap2 || 39// || `[0x00067fff8000, 0x000a7fff7fff]` || MidShadow || 40// || `[0x00008fff7000, 0x00067fff7fff]` || ShadowGap || 41// || `[0x00007fff8000, 0x00008fff6fff]` || LowShadow || 42// || `[0x000000000000, 0x00007fff7fff]` || LowMem || 43// 44// Default Linux/i386 mapping on x86_64 machine: 45// || `[0x40000000, 0xffffffff]` || HighMem || 46// || `[0x28000000, 0x3fffffff]` || HighShadow || 47// || `[0x24000000, 0x27ffffff]` || ShadowGap || 48// || `[0x20000000, 0x23ffffff]` || LowShadow || 49// || `[0x00000000, 0x1fffffff]` || LowMem || 50// 51// Default Linux/i386 mapping on i386 machine 52// (addresses starting with 0xc0000000 are reserved 53// for kernel and thus not sanitized): 54// || `[0x38000000, 0xbfffffff]` || HighMem || 55// || `[0x27000000, 0x37ffffff]` || HighShadow || 56// || `[0x24000000, 0x26ffffff]` || ShadowGap || 57// || `[0x20000000, 0x23ffffff]` || LowShadow || 58// || `[0x00000000, 0x1fffffff]` || LowMem || 59// 60// Default Linux/MIPS32 mapping: 61// || `[0x2aaa0000, 0xffffffff]` || HighMem || 62// || `[0x0fff4000, 0x2aa9ffff]` || HighShadow || 63// || `[0x0bff4000, 0x0fff3fff]` || ShadowGap || 64// || `[0x0aaa0000, 0x0bff3fff]` || LowShadow || 65// || `[0x00000000, 0x0aa9ffff]` || LowMem || 66// 67// Default Linux/MIPS64 mapping: 68// || `[0x4000000000, 0xffffffffff]` || HighMem || 69// || `[0x2800000000, 0x3fffffffff]` || HighShadow || 70// || `[0x2400000000, 0x27ffffffff]` || ShadowGap || 71// || `[0x2000000000, 0x23ffffffff]` || LowShadow || 72// || `[0x0000000000, 0x1fffffffff]` || LowMem || 73// 74// Default Linux/AArch64 (39-bit VMA) mapping: 75// || `[0x2000000000, 0x7fffffffff]` || highmem || 76// || `[0x1400000000, 0x1fffffffff]` || highshadow || 77// || `[0x1200000000, 0x13ffffffff]` || shadowgap || 78// || `[0x1000000000, 0x11ffffffff]` || lowshadow || 79// || `[0x0000000000, 0x0fffffffff]` || lowmem || 80// 81// Default Linux/AArch64 (42-bit VMA) mapping: 82// || `[0x10000000000, 0x3ffffffffff]` || highmem || 83// || `[0x0a000000000, 0x0ffffffffff]` || highshadow || 84// || `[0x09000000000, 0x09fffffffff]` || shadowgap || 85// || `[0x08000000000, 0x08fffffffff]` || lowshadow || 86// || `[0x00000000000, 0x07fffffffff]` || lowmem || 87// 88// Shadow mapping on FreeBSD/x86-64 with SHADOW_OFFSET == 0x400000000000: 89// || `[0x500000000000, 0x7fffffffffff]` || HighMem || 90// || `[0x4a0000000000, 0x4fffffffffff]` || HighShadow || 91// || `[0x480000000000, 0x49ffffffffff]` || ShadowGap || 92// || `[0x400000000000, 0x47ffffffffff]` || LowShadow || 93// || `[0x000000000000, 0x3fffffffffff]` || LowMem || 94// 95// Shadow mapping on FreeBSD/i386 with SHADOW_OFFSET == 0x40000000: 96// || `[0x60000000, 0xffffffff]` || HighMem || 97// || `[0x4c000000, 0x5fffffff]` || HighShadow || 98// || `[0x48000000, 0x4bffffff]` || ShadowGap || 99// || `[0x40000000, 0x47ffffff]` || LowShadow || 100// || `[0x00000000, 0x3fffffff]` || LowMem || 101// 102// Default Windows/i386 mapping: 103// (the exact location of HighShadow/HighMem may vary depending 104// on WoW64, /LARGEADDRESSAWARE, etc). 105// || `[0x50000000, 0xffffffff]` || HighMem || 106// || `[0x3a000000, 0x4fffffff]` || HighShadow || 107// || `[0x36000000, 0x39ffffff]` || ShadowGap || 108// || `[0x30000000, 0x35ffffff]` || LowShadow || 109// || `[0x00000000, 0x2fffffff]` || LowMem || 110 111static const u64 kDefaultShadowScale = 3; 112static const u64 kDefaultShadowOffset32 = 1ULL << 29; // 0x20000000 113static const u64 kDefaultShadowOffset64 = 1ULL << 44; 114static const u64 kDefaultShort64bitShadowOffset = 0x7FFF8000; // < 2G. 115static const u64 kIosShadowOffset32 = 1ULL << 30; // 0x40000000 116static const u64 kIosShadowOffset64 = 0x130000000; 117static const u64 kIosSimShadowOffset32 = 1ULL << 30; 118static const u64 kIosSimShadowOffset64 = kDefaultShadowOffset64; 119static const u64 kAArch64_ShadowOffset64 = 1ULL << 36; 120static const u64 kMIPS32_ShadowOffset32 = 0x0aaa0000; 121static const u64 kMIPS64_ShadowOffset64 = 1ULL << 37; 122static const u64 kPPC64_ShadowOffset64 = 1ULL << 41; 123static const u64 kFreeBSD_ShadowOffset32 = 1ULL << 30; // 0x40000000 124static const u64 kFreeBSD_ShadowOffset64 = 1ULL << 46; // 0x400000000000 125static const u64 kWindowsShadowOffset32 = 3ULL << 28; // 0x30000000 126 127#define SHADOW_SCALE kDefaultShadowScale 128 129 130#if SANITIZER_WORDSIZE == 32 131# if SANITIZER_ANDROID 132# define SHADOW_OFFSET (0) 133# elif defined(__mips__) 134# define SHADOW_OFFSET kMIPS32_ShadowOffset32 135# elif SANITIZER_FREEBSD 136# define SHADOW_OFFSET kFreeBSD_ShadowOffset32 137# elif SANITIZER_WINDOWS 138# define SHADOW_OFFSET kWindowsShadowOffset32 139# elif SANITIZER_IOSSIM 140# define SHADOW_OFFSET kIosSimShadowOffset32 141# elif SANITIZER_IOS 142# define SHADOW_OFFSET kIosShadowOffset32 143# else 144# define SHADOW_OFFSET kDefaultShadowOffset32 145# endif 146#else 147# if defined(__aarch64__) 148# define SHADOW_OFFSET kAArch64_ShadowOffset64 149# elif defined(__powerpc64__) 150# define SHADOW_OFFSET kPPC64_ShadowOffset64 151# elif SANITIZER_FREEBSD 152# define SHADOW_OFFSET kFreeBSD_ShadowOffset64 153# elif SANITIZER_MAC 154# define SHADOW_OFFSET kDefaultShadowOffset64 155# elif defined(__mips64) 156# define SHADOW_OFFSET kMIPS64_ShadowOffset64 157# elif SANITIZER_IOSSIM 158# define SHADOW_OFFSET kIosSimShadowOffset64 159# elif SANITIZER_IOS 160# define SHADOW_OFFSET kIosShadowOffset64 161# else 162# define SHADOW_OFFSET kDefaultShort64bitShadowOffset 163# endif 164#endif 165 166#define SHADOW_GRANULARITY (1ULL << SHADOW_SCALE) 167#define MEM_TO_SHADOW(mem) (((mem) >> SHADOW_SCALE) + (SHADOW_OFFSET)) 168#define SHADOW_TO_MEM(shadow) (((shadow) - SHADOW_OFFSET) << SHADOW_SCALE) 169 170#define kLowMemBeg 0 171#define kLowMemEnd (SHADOW_OFFSET ? SHADOW_OFFSET - 1 : 0) 172 173#define kLowShadowBeg SHADOW_OFFSET 174#define kLowShadowEnd MEM_TO_SHADOW(kLowMemEnd) 175 176#define kHighMemBeg (MEM_TO_SHADOW(kHighMemEnd) + 1) 177 178#define kHighShadowBeg MEM_TO_SHADOW(kHighMemBeg) 179#define kHighShadowEnd MEM_TO_SHADOW(kHighMemEnd) 180 181# define kMidShadowBeg MEM_TO_SHADOW(kMidMemBeg) 182# define kMidShadowEnd MEM_TO_SHADOW(kMidMemEnd) 183 184// With the zero shadow base we can not actually map pages starting from 0. 185// This constant is somewhat arbitrary. 186#define kZeroBaseShadowStart 0 187#define kZeroBaseMaxShadowStart (1 << 18) 188 189#define kShadowGapBeg (kLowShadowEnd ? kLowShadowEnd + 1 \ 190 : kZeroBaseShadowStart) 191#define kShadowGapEnd ((kMidMemBeg ? kMidShadowBeg : kHighShadowBeg) - 1) 192 193#define kShadowGap2Beg (kMidMemBeg ? kMidShadowEnd + 1 : 0) 194#define kShadowGap2End (kMidMemBeg ? kMidMemBeg - 1 : 0) 195 196#define kShadowGap3Beg (kMidMemBeg ? kMidMemEnd + 1 : 0) 197#define kShadowGap3End (kMidMemBeg ? kHighShadowBeg - 1 : 0) 198 199#define DO_ASAN_MAPPING_PROFILE 0 // Set to 1 to profile the functions below. 200 201#if DO_ASAN_MAPPING_PROFILE 202# define PROFILE_ASAN_MAPPING() AsanMappingProfile[__LINE__]++; 203#else 204# define PROFILE_ASAN_MAPPING() 205#endif 206 207// If 1, all shadow boundaries are constants. 208// Don't set to 1 other than for testing. 209#define ASAN_FIXED_MAPPING 0 210 211namespace __asan { 212 213extern uptr AsanMappingProfile[]; 214 215#if ASAN_FIXED_MAPPING 216// Fixed mapping for 64-bit Linux. Mostly used for performance comparison 217// with non-fixed mapping. As of r175253 (Feb 2013) the performance 218// difference between fixed and non-fixed mapping is below the noise level. 219static uptr kHighMemEnd = 0x7fffffffffffULL; 220static uptr kMidMemBeg = 0x3000000000ULL; 221static uptr kMidMemEnd = 0x4fffffffffULL; 222#else 223extern uptr kHighMemEnd, kMidMemBeg, kMidMemEnd; // Initialized in __asan_init. 224#endif 225 226static inline bool AddrIsInLowMem(uptr a) { 227 PROFILE_ASAN_MAPPING(); 228 return a < kLowMemEnd; 229} 230 231static inline bool AddrIsInLowShadow(uptr a) { 232 PROFILE_ASAN_MAPPING(); 233 return a >= kLowShadowBeg && a <= kLowShadowEnd; 234} 235 236static inline bool AddrIsInHighMem(uptr a) { 237 PROFILE_ASAN_MAPPING(); 238 return a >= kHighMemBeg && a <= kHighMemEnd; 239} 240 241static inline bool AddrIsInMidMem(uptr a) { 242 PROFILE_ASAN_MAPPING(); 243 return kMidMemBeg && a >= kMidMemBeg && a <= kMidMemEnd; 244} 245 246static inline bool AddrIsInMem(uptr a) { 247 PROFILE_ASAN_MAPPING(); 248 return AddrIsInLowMem(a) || AddrIsInMidMem(a) || AddrIsInHighMem(a); 249} 250 251static inline uptr MemToShadow(uptr p) { 252 PROFILE_ASAN_MAPPING(); 253 CHECK(AddrIsInMem(p)); 254 return MEM_TO_SHADOW(p); 255} 256 257static inline bool AddrIsInHighShadow(uptr a) { 258 PROFILE_ASAN_MAPPING(); 259 return a >= kHighShadowBeg && a <= kHighMemEnd; 260} 261 262static inline bool AddrIsInMidShadow(uptr a) { 263 PROFILE_ASAN_MAPPING(); 264 return kMidMemBeg && a >= kMidShadowBeg && a <= kMidMemEnd; 265} 266 267static inline bool AddrIsInShadow(uptr a) { 268 PROFILE_ASAN_MAPPING(); 269 return AddrIsInLowShadow(a) || AddrIsInMidShadow(a) || AddrIsInHighShadow(a); 270} 271 272static inline bool AddrIsInShadowGap(uptr a) { 273 PROFILE_ASAN_MAPPING(); 274 if (kMidMemBeg) { 275 if (a <= kShadowGapEnd) 276 return SHADOW_OFFSET == 0 || a >= kShadowGapBeg; 277 return (a >= kShadowGap2Beg && a <= kShadowGap2End) || 278 (a >= kShadowGap3Beg && a <= kShadowGap3End); 279 } 280 // In zero-based shadow mode we treat addresses near zero as addresses 281 // in shadow gap as well. 282 if (SHADOW_OFFSET == 0) 283 return a <= kShadowGapEnd; 284 return a >= kShadowGapBeg && a <= kShadowGapEnd; 285} 286 287static inline bool AddrIsAlignedByGranularity(uptr a) { 288 PROFILE_ASAN_MAPPING(); 289 return (a & (SHADOW_GRANULARITY - 1)) == 0; 290} 291 292static inline bool AddressIsPoisoned(uptr a) { 293 PROFILE_ASAN_MAPPING(); 294 const uptr kAccessSize = 1; 295 u8 *shadow_address = (u8*)MEM_TO_SHADOW(a); 296 s8 shadow_value = *shadow_address; 297 if (shadow_value) { 298 u8 last_accessed_byte = (a & (SHADOW_GRANULARITY - 1)) 299 + kAccessSize - 1; 300 return (last_accessed_byte >= shadow_value); 301 } 302 return false; 303} 304 305// Must be after all calls to PROFILE_ASAN_MAPPING(). 306static const uptr kAsanMappingProfileSize = __LINE__; 307 308} // namespace __asan 309 310#endif // ASAN_MAPPING_H 311