asan_mapping.h revision 238901
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: 20229109Sed// http://code.google.com/p/address-sanitizer/wiki/AddressSanitizerAlgorithm 21229109Sed 22229109Sed#if ASAN_FLEXIBLE_MAPPING_AND_OFFSET == 1 23238901Sandrewextern __attribute__((visibility("default"))) uptr __asan_mapping_scale; 24238901Sandrewextern __attribute__((visibility("default"))) uptr __asan_mapping_offset; 25238901Sandrew# define SHADOW_SCALE (__asan_mapping_scale) 26238901Sandrew# define SHADOW_OFFSET (__asan_mapping_offset) 27229109Sed#else 28238901Sandrew# ifdef ANDROID 29238901Sandrew# define SHADOW_SCALE (3) 30238901Sandrew# define SHADOW_OFFSET (0) 31238901Sandrew# else 32238901Sandrew# define SHADOW_SCALE (3) 33238901Sandrew# if __WORDSIZE == 32 34238901Sandrew# define SHADOW_OFFSET (1 << 29) 35238901Sandrew# else 36238901Sandrew# define SHADOW_OFFSET (1ULL << 44) 37238901Sandrew# endif 38238901Sandrew# endif 39229109Sed#endif // ASAN_FLEXIBLE_MAPPING_AND_OFFSET 40229109Sed 41229109Sed#define SHADOW_GRANULARITY (1ULL << SHADOW_SCALE) 42229109Sed#define MEM_TO_SHADOW(mem) (((mem) >> SHADOW_SCALE) | (SHADOW_OFFSET)) 43238901Sandrew#define SHADOW_TO_MEM(shadow) (((shadow) - SHADOW_OFFSET) << SHADOW_SCALE) 44229109Sed 45229109Sed#if __WORDSIZE == 64 46238901Sandrew static const uptr kHighMemEnd = 0x00007fffffffffffUL; 47229109Sed#else // __WORDSIZE == 32 48238901Sandrew static const uptr kHighMemEnd = 0xffffffff; 49229109Sed#endif // __WORDSIZE 50229109Sed 51229109Sed 52229109Sed#define kLowMemBeg 0 53229109Sed#define kLowMemEnd (SHADOW_OFFSET ? SHADOW_OFFSET - 1 : 0) 54229109Sed 55229109Sed#define kLowShadowBeg SHADOW_OFFSET 56229109Sed#define kLowShadowEnd MEM_TO_SHADOW(kLowMemEnd) 57229109Sed 58229109Sed#define kHighMemBeg (MEM_TO_SHADOW(kHighMemEnd) + 1) 59229109Sed 60229109Sed#define kHighShadowBeg MEM_TO_SHADOW(kHighMemBeg) 61229109Sed#define kHighShadowEnd MEM_TO_SHADOW(kHighMemEnd) 62229109Sed 63229109Sed#define kShadowGapBeg (kLowShadowEnd ? kLowShadowEnd + 1 : 16 * kPageSize) 64229109Sed#define kShadowGapEnd (kHighShadowBeg - 1) 65229109Sed 66229109Sed#define kGlobalAndStackRedzone \ 67229109Sed (SHADOW_GRANULARITY < 32 ? 32 : SHADOW_GRANULARITY) 68229109Sed 69229109Sednamespace __asan { 70229109Sed 71238901Sandrewstatic inline bool AddrIsInLowMem(uptr a) { 72229109Sed return a < kLowMemEnd; 73229109Sed} 74229109Sed 75238901Sandrewstatic inline bool AddrIsInLowShadow(uptr a) { 76229109Sed return a >= kLowShadowBeg && a <= kLowShadowEnd; 77229109Sed} 78229109Sed 79238901Sandrewstatic inline bool AddrIsInHighMem(uptr a) { 80229109Sed return a >= kHighMemBeg && a <= kHighMemEnd; 81229109Sed} 82229109Sed 83238901Sandrewstatic inline bool AddrIsInMem(uptr a) { 84229109Sed return AddrIsInLowMem(a) || AddrIsInHighMem(a); 85229109Sed} 86229109Sed 87238901Sandrewstatic inline uptr MemToShadow(uptr p) { 88229109Sed CHECK(AddrIsInMem(p)); 89229109Sed return MEM_TO_SHADOW(p); 90229109Sed} 91229109Sed 92238901Sandrewstatic inline bool AddrIsInHighShadow(uptr a) { 93229109Sed return a >= kHighShadowBeg && a <= kHighMemEnd; 94229109Sed} 95229109Sed 96238901Sandrewstatic inline bool AddrIsInShadow(uptr a) { 97229109Sed return AddrIsInLowShadow(a) || AddrIsInHighShadow(a); 98229109Sed} 99229109Sed 100238901Sandrewstatic inline bool AddrIsInShadowGap(uptr a) { 101238901Sandrew return a >= kShadowGapBeg && a <= kShadowGapEnd; 102238901Sandrew} 103238901Sandrew 104238901Sandrewstatic inline bool AddrIsAlignedByGranularity(uptr a) { 105229109Sed return (a & (SHADOW_GRANULARITY - 1)) == 0; 106229109Sed} 107229109Sed 108238901Sandrewstatic inline bool AddressIsPoisoned(uptr a) { 109238901Sandrew const uptr kAccessSize = 1; 110238901Sandrew u8 *shadow_address = (u8*)MemToShadow(a); 111238901Sandrew s8 shadow_value = *shadow_address; 112238901Sandrew if (shadow_value) { 113238901Sandrew u8 last_accessed_byte = (a & (SHADOW_GRANULARITY - 1)) 114238901Sandrew + kAccessSize - 1; 115238901Sandrew return (last_accessed_byte >= shadow_value); 116238901Sandrew } 117238901Sandrew return false; 118238901Sandrew} 119238901Sandrew 120229109Sed} // namespace __asan 121229109Sed 122229109Sed#endif // ASAN_MAPPING_H 123