diff options
Diffstat (limited to 'lib/asan/asan_mapping.h')
| -rw-r--r-- | lib/asan/asan_mapping.h | 131 |
1 files changed, 110 insertions, 21 deletions
diff --git a/lib/asan/asan_mapping.h b/lib/asan/asan_mapping.h index 5e3067031f4a3..f04629222419e 100644 --- a/lib/asan/asan_mapping.h +++ b/lib/asan/asan_mapping.h @@ -18,6 +18,37 @@ // The full explanation of the memory mapping could be found here: // http://code.google.com/p/address-sanitizer/wiki/AddressSanitizerAlgorithm +// +// Typical shadow mapping on Linux/x86_64 with SHADOW_OFFSET == 0x00007fff8000: +// || `[0x10007fff8000, 0x7fffffffffff]` || HighMem || +// || `[0x02008fff7000, 0x10007fff7fff]` || HighShadow || +// || `[0x00008fff7000, 0x02008fff6fff]` || ShadowGap || +// || `[0x00007fff8000, 0x00008fff6fff]` || LowShadow || +// || `[0x000000000000, 0x00007fff7fff]` || LowMem || +// +// When SHADOW_OFFSET is zero (-pie): +// || `[0x100000000000, 0x7fffffffffff]` || HighMem || +// || `[0x020000000000, 0x0fffffffffff]` || HighShadow || +// || `[0x000000040000, 0x01ffffffffff]` || ShadowGap || +// +// Special case when something is already mapped between +// 0x003000000000 and 0x005000000000 (e.g. when prelink is installed): +// || `[0x10007fff8000, 0x7fffffffffff]` || HighMem || +// || `[0x02008fff7000, 0x10007fff7fff]` || HighShadow || +// || `[0x005000000000, 0x02008fff6fff]` || ShadowGap3 || +// || `[0x003000000000, 0x004fffffffff]` || MidMem || +// || `[0x000a7fff8000, 0x002fffffffff]` || ShadowGap2 || +// || `[0x00067fff8000, 0x000a7fff7fff]` || MidShadow || +// || `[0x00008fff7000, 0x00067fff7fff]` || ShadowGap || +// || `[0x00007fff8000, 0x00008fff6fff]` || LowShadow || +// || `[0x000000000000, 0x00007fff7fff]` || LowMem || +// +// Default Linux/i386 mapping: +// || `[0x40000000, 0xffffffff]` || HighMem || +// || `[0x28000000, 0x3fffffff]` || HighShadow || +// || `[0x24000000, 0x27ffffff]` || ShadowGap || +// || `[0x20000000, 0x23ffffff]` || LowShadow || +// || `[0x00000000, 0x1fffffff]` || LowMem || #if ASAN_FLEXIBLE_MAPPING_AND_OFFSET == 1 extern SANITIZER_INTERFACE_ATTRIBUTE uptr __asan_mapping_scale; @@ -25,7 +56,7 @@ extern SANITIZER_INTERFACE_ATTRIBUTE uptr __asan_mapping_offset; # define SHADOW_SCALE (__asan_mapping_scale) # define SHADOW_OFFSET (__asan_mapping_offset) #else -# if ASAN_ANDROID +# if SANITIZER_ANDROID # define SHADOW_SCALE (3) # define SHADOW_OFFSET (0) # else @@ -36,27 +67,20 @@ extern SANITIZER_INTERFACE_ATTRIBUTE uptr __asan_mapping_offset; # if defined(__powerpc64__) # define SHADOW_OFFSET (1ULL << 41) # else -# define SHADOW_OFFSET (1ULL << 44) +# if SANITIZER_MAC +# define SHADOW_OFFSET (1ULL << 44) +# else +# define SHADOW_OFFSET 0x7fff8000ULL +# endif # endif # endif # endif #endif // ASAN_FLEXIBLE_MAPPING_AND_OFFSET #define SHADOW_GRANULARITY (1ULL << SHADOW_SCALE) -#define MEM_TO_SHADOW(mem) (((mem) >> SHADOW_SCALE) | (SHADOW_OFFSET)) +#define MEM_TO_SHADOW(mem) (((mem) >> SHADOW_SCALE) + (SHADOW_OFFSET)) #define SHADOW_TO_MEM(shadow) (((shadow) - SHADOW_OFFSET) << SHADOW_SCALE) -#if SANITIZER_WORDSIZE == 64 -# if defined(__powerpc64__) - static const uptr kHighMemEnd = 0x00000fffffffffffUL; -# else - static const uptr kHighMemEnd = 0x00007fffffffffffUL; -# endif -#else // SANITIZER_WORDSIZE == 32 - static const uptr kHighMemEnd = 0xffffffff; -#endif // SANITIZER_WORDSIZE - - #define kLowMemBeg 0 #define kLowMemEnd (SHADOW_OFFSET ? SHADOW_OFFSET - 1 : 0) @@ -68,59 +92,121 @@ extern SANITIZER_INTERFACE_ATTRIBUTE uptr __asan_mapping_offset; #define kHighShadowBeg MEM_TO_SHADOW(kHighMemBeg) #define kHighShadowEnd MEM_TO_SHADOW(kHighMemEnd) +# define kMidShadowBeg MEM_TO_SHADOW(kMidMemBeg) +# define kMidShadowEnd MEM_TO_SHADOW(kMidMemEnd) + // With the zero shadow base we can not actually map pages starting from 0. // This constant is somewhat arbitrary. #define kZeroBaseShadowStart (1 << 18) #define kShadowGapBeg (kLowShadowEnd ? kLowShadowEnd + 1 \ : kZeroBaseShadowStart) -#define kShadowGapEnd (kHighShadowBeg - 1) +#define kShadowGapEnd ((kMidMemBeg ? kMidShadowBeg : kHighShadowBeg) - 1) -#define kGlobalAndStackRedzone \ - (SHADOW_GRANULARITY < 32 ? 32 : SHADOW_GRANULARITY) +#define kShadowGap2Beg (kMidMemBeg ? kMidShadowEnd + 1 : 0) +#define kShadowGap2End (kMidMemBeg ? kMidMemBeg - 1 : 0) + +#define kShadowGap3Beg (kMidMemBeg ? kMidMemEnd + 1 : 0) +#define kShadowGap3End (kMidMemBeg ? kHighShadowBeg - 1 : 0) + +#define DO_ASAN_MAPPING_PROFILE 0 // Set to 1 to profile the functions below. + +#if DO_ASAN_MAPPING_PROFILE +# define PROFILE_ASAN_MAPPING() AsanMappingProfile[__LINE__]++; +#else +# define PROFILE_ASAN_MAPPING() +#endif + +// If 1, all shadow boundaries are constants. +// Don't set to 1 other than for testing. +#define ASAN_FIXED_MAPPING 0 namespace __asan { +extern uptr AsanMappingProfile[]; + +#if ASAN_FIXED_MAPPING +// Fixed mapping for 64-bit Linux. Mostly used for performance comparison +// with non-fixed mapping. As of r175253 (Feb 2013) the performance +// difference between fixed and non-fixed mapping is below the noise level. +static uptr kHighMemEnd = 0x7fffffffffffULL; +static uptr kMidMemBeg = 0x3000000000ULL; +static uptr kMidMemEnd = 0x4fffffffffULL; +#else +SANITIZER_INTERFACE_ATTRIBUTE +extern uptr kHighMemEnd, kMidMemBeg, kMidMemEnd; // Initialized in __asan_init. +#endif + static inline bool AddrIsInLowMem(uptr a) { + PROFILE_ASAN_MAPPING(); return a < kLowMemEnd; } static inline bool AddrIsInLowShadow(uptr a) { + PROFILE_ASAN_MAPPING(); return a >= kLowShadowBeg && a <= kLowShadowEnd; } static inline bool AddrIsInHighMem(uptr a) { + PROFILE_ASAN_MAPPING(); return a >= kHighMemBeg && a <= kHighMemEnd; } +static inline bool AddrIsInMidMem(uptr a) { + PROFILE_ASAN_MAPPING(); + return kMidMemBeg && a >= kMidMemBeg && a <= kMidMemEnd; +} + static inline bool AddrIsInMem(uptr a) { - return AddrIsInLowMem(a) || AddrIsInHighMem(a); + PROFILE_ASAN_MAPPING(); + return AddrIsInLowMem(a) || AddrIsInMidMem(a) || AddrIsInHighMem(a); } static inline uptr MemToShadow(uptr p) { + PROFILE_ASAN_MAPPING(); CHECK(AddrIsInMem(p)); return MEM_TO_SHADOW(p); } static inline bool AddrIsInHighShadow(uptr a) { - return a >= kHighShadowBeg && a <= kHighMemEnd; + PROFILE_ASAN_MAPPING(); + return a >= kHighShadowBeg && a <= kHighMemEnd; +} + +static inline bool AddrIsInMidShadow(uptr a) { + PROFILE_ASAN_MAPPING(); + return kMidMemBeg && a >= kMidShadowBeg && a <= kMidMemEnd; } static inline bool AddrIsInShadow(uptr a) { - return AddrIsInLowShadow(a) || AddrIsInHighShadow(a); + PROFILE_ASAN_MAPPING(); + return AddrIsInLowShadow(a) || AddrIsInMidShadow(a) || AddrIsInHighShadow(a); } static inline bool AddrIsInShadowGap(uptr a) { + PROFILE_ASAN_MAPPING(); + if (kMidMemBeg) { + if (a <= kShadowGapEnd) + return SHADOW_OFFSET == 0 || a >= kShadowGapBeg; + return (a >= kShadowGap2Beg && a <= kShadowGap2End) || + (a >= kShadowGap3Beg && a <= kShadowGap3End); + } + // In zero-based shadow mode we treat addresses near zero as addresses + // in shadow gap as well. + if (SHADOW_OFFSET == 0) + return a <= kShadowGapEnd; return a >= kShadowGapBeg && a <= kShadowGapEnd; } static inline bool AddrIsAlignedByGranularity(uptr a) { + PROFILE_ASAN_MAPPING(); return (a & (SHADOW_GRANULARITY - 1)) == 0; } static inline bool AddressIsPoisoned(uptr a) { + PROFILE_ASAN_MAPPING(); const uptr kAccessSize = 1; - u8 *shadow_address = (u8*)MemToShadow(a); + u8 *shadow_address = (u8*)MEM_TO_SHADOW(a); s8 shadow_value = *shadow_address; if (shadow_value) { u8 last_accessed_byte = (a & (SHADOW_GRANULARITY - 1)) @@ -130,6 +216,9 @@ static inline bool AddressIsPoisoned(uptr a) { return false; } +// Must be after all calls to PROFILE_ASAN_MAPPING(). +static const uptr kAsanMappingProfileSize = __LINE__; + } // namespace __asan #endif // ASAN_MAPPING_H |