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Diffstat (limited to 'lib/esan/esan_shadow.h')
| -rw-r--r-- | lib/esan/esan_shadow.h | 292 |
1 files changed, 0 insertions, 292 deletions
diff --git a/lib/esan/esan_shadow.h b/lib/esan/esan_shadow.h deleted file mode 100644 index b76a9ccbd..000000000 --- a/lib/esan/esan_shadow.h +++ /dev/null @@ -1,292 +0,0 @@ -//===-- esan_shadow.h -------------------------------------------*- C++ -*-===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// This file is a part of EfficiencySanitizer, a family of performance tuners. -// -// Shadow memory mappings for the esan run-time. -//===----------------------------------------------------------------------===// - -#ifndef ESAN_SHADOW_H -#define ESAN_SHADOW_H - -#include "esan.h" -#include <sanitizer_common/sanitizer_platform.h> - -#if SANITIZER_WORDSIZE != 64 -#error Only 64-bit is supported -#endif - -namespace __esan { - -struct ApplicationRegion { - uptr Start; - uptr End; - bool ShadowMergedWithPrev; -}; - -#if (SANITIZER_LINUX || SANITIZER_FREEBSD) && defined(__x86_64__) -// Linux x86_64 -// -// Application memory falls into these 5 regions (ignoring the corner case -// of PIE with a non-zero PT_LOAD base): -// -// [0x00000000'00000000, 0x00000100'00000000) non-PIE + heap -// [0x00005500'00000000, 0x00005700'00000000) PIE -// [0x00007e00'00000000, 0x00007fff'ff600000) libraries + stack, part 1 -// [0x00007fff'ff601000, 0x00008000'00000000) libraries + stack, part 2 -// [0xffffffff'ff600000, 0xffffffff'ff601000) vsyscall -// -// Although we can ignore the vsyscall for the most part as there are few data -// references there (other sanitizers ignore it), we enforce a gap inside the -// library region to distinguish the vsyscall's shadow, considering this gap to -// be an invalid app region. -// We disallow application memory outside of those 5 regions. -// Our regions assume that the stack rlimit is less than a terabyte (otherwise -// the Linux kernel's default mmap region drops below 0x7e00'), which we enforce -// at init time (we can support larger and unlimited sizes for shadow -// scaledowns, but it is difficult for 1:1 mappings). -// -// Our shadow memory is scaled from a 1:1 mapping and supports a scale -// specified at library initialization time that can be any power-of-2 -// scaledown (1x, 2x, 4x, 8x, 16x, etc.). -// -// We model our shadow memory after Umbra, a library used by the Dr. Memory -// tool: https://github.com/DynamoRIO/drmemory/blob/master/umbra/umbra_x64.c. -// We use Umbra's scheme as it was designed to support different -// offsets, it supports two different shadow mappings (which we may want to -// use for future tools), and it ensures that the shadow of a shadow will -// not overlap either shadow memory or application memory. -// -// This formula translates from application memory to shadow memory: -// -// shadow(app) = ((app & 0x00000fff'ffffffff) + offset) >> scale -// -// Where the offset for 1:1 is 0x00001300'00000000. For other scales, the -// offset is shifted left by the scale, except for scales of 1 and 2 where -// it must be tweaked in order to pass the double-shadow test -// (see the "shadow(shadow)" comments below): -// scale == 0: 0x00001300'000000000 -// scale == 1: 0x00002200'000000000 -// scale == 2: 0x00004400'000000000 -// scale >= 3: (0x00001300'000000000 << scale) -// -// Do not pass in the open-ended end value to the formula as it will fail. -// -// The resulting shadow memory regions for a 0 scaling are: -// -// [0x00001300'00000000, 0x00001400'00000000) -// [0x00001800'00000000, 0x00001a00'00000000) -// [0x00002100'00000000, 0x000022ff'ff600000) -// [0x000022ff'ff601000, 0x00002300'00000000) -// [0x000022ff'ff600000, 0x000022ff'ff601000] -// -// We also want to ensure that a wild access by the application into the shadow -// regions will not corrupt our own shadow memory. shadow(shadow) ends up -// disjoint from shadow(app): -// -// [0x00001600'00000000, 0x00001700'00000000) -// [0x00001b00'00000000, 0x00001d00'00000000) -// [0x00001400'00000000, 0x000015ff'ff600000] -// [0x000015ff'ff601000, 0x00001600'00000000] -// [0x000015ff'ff600000, 0x000015ff'ff601000] - -static const struct ApplicationRegion AppRegions[] = { - {0x0000000000000000ull, 0x0000010000000000u, false}, - {0x0000550000000000u, 0x0000570000000000u, false}, - // We make one shadow mapping to hold the shadow regions for all 3 of these - // app regions, as the mappings interleave, and the gap between the 3rd and - // 4th scales down below a page. - {0x00007e0000000000u, 0x00007fffff600000u, false}, - {0x00007fffff601000u, 0x0000800000000000u, true}, - {0xffffffffff600000u, 0xffffffffff601000u, true}, -}; - -#elif SANITIZER_LINUX && SANITIZER_MIPS64 - -// Application memory falls into these 3 regions -// -// [0x00000001'00000000, 0x00000002'00000000) non-PIE + heap -// [0x000000aa'00000000, 0x000000ab'00000000) PIE -// [0x000000ff'00000000, 0x000000ff'ffffffff) libraries + stack -// -// This formula translates from application memory to shadow memory: -// -// shadow(app) = ((app & 0x00000f'ffffffff) + offset) >> scale -// -// Where the offset for 1:1 is 0x000013'00000000. For other scales, the -// offset is shifted left by the scale, except for scales of 1 and 2 where -// it must be tweaked in order to pass the double-shadow test -// (see the "shadow(shadow)" comments below): -// scale == 0: 0x000013'00000000 -// scale == 1: 0x000022'00000000 -// scale == 2: 0x000044'00000000 -// scale >= 3: (0x000013'00000000 << scale) -// -// The resulting shadow memory regions for a 0 scaling are: -// -// [0x00000014'00000000, 0x00000015'00000000) -// [0x0000001d'00000000, 0x0000001e'00000000) -// [0x00000022'00000000, 0x00000022'ffffffff) -// -// We also want to ensure that a wild access by the application into the shadow -// regions will not corrupt our own shadow memory. shadow(shadow) ends up -// disjoint from shadow(app): -// -// [0x00000017'00000000, 0x00000018'00000000) -// [0x00000020'00000000, 0x00000021'00000000) -// [0x00000015'00000000, 0x00000015'ffffffff] - -static const struct ApplicationRegion AppRegions[] = { - {0x0100000000u, 0x0200000000u, false}, - {0xaa00000000u, 0xab00000000u, false}, - {0xff00000000u, 0xffffffffffu, false}, -}; - -#else -#error Platform not supported -#endif - -static const u32 NumAppRegions = sizeof(AppRegions)/sizeof(AppRegions[0]); - -// See the comment above: we do not currently support a stack size rlimit -// equal to or larger than 1TB. -static const uptr MaxStackSize = (1ULL << 40) - 4096; - -class ShadowMapping { -public: - - // The scale and offset vary by tool. - uptr Scale; - uptr Offset; - - // TODO(sagar.thakur): Try to hardcode the mask as done in the compiler - // instrumentation to reduce the runtime cost of appToShadow. - struct ShadowMemoryMask40 { - static const uptr Mask = 0x0000000fffffffffu; - }; - - struct ShadowMemoryMask47 { - static const uptr Mask = 0x00000fffffffffffu; - }; - - void initialize(uptr ShadowScale) { - - const uptr OffsetArray40[3] = { - 0x0000001300000000u, - 0x0000002200000000u, - 0x0000004400000000u, - }; - - const uptr OffsetArray47[3] = { - 0x0000130000000000u, - 0x0000220000000000u, - 0x0000440000000000u, - }; - - Scale = ShadowScale; - switch (VmaSize) { - case 40: { - if (Scale <= 2) - Offset = OffsetArray40[Scale]; - else - Offset = OffsetArray40[0] << Scale; - } - break; - case 47: { - if (Scale <= 2) - Offset = OffsetArray47[Scale]; - else - Offset = OffsetArray47[0] << Scale; - } - break; - default: { - Printf("ERROR: %d-bit virtual memory address size not supported\n", VmaSize); - Die(); - } - } - } -}; -extern ShadowMapping Mapping; - -static inline bool getAppRegion(u32 i, uptr *Start, uptr *End) { - if (i >= NumAppRegions) - return false; - *Start = AppRegions[i].Start; - *End = AppRegions[i].End; - return true; -} - -ALWAYS_INLINE -bool isAppMem(uptr Mem) { - for (u32 i = 0; i < NumAppRegions; ++i) { - if (Mem >= AppRegions[i].Start && Mem < AppRegions[i].End) - return true; - } - return false; -} - -template<typename Params> -uptr appToShadowImpl(uptr App) { - return (((App & Params::Mask) + Mapping.Offset) >> Mapping.Scale); -} - -ALWAYS_INLINE -uptr appToShadow(uptr App) { - switch (VmaSize) { - case 40: return appToShadowImpl<ShadowMapping::ShadowMemoryMask40>(App); - case 47: return appToShadowImpl<ShadowMapping::ShadowMemoryMask47>(App); - default: { - Printf("ERROR: %d-bit virtual memory address size not supported\n", VmaSize); - Die(); - } - } -} - -static inline bool getShadowRegion(u32 i, uptr *Start, uptr *End) { - if (i >= NumAppRegions) - return false; - u32 UnmergedShadowCount = 0; - u32 AppIdx; - for (AppIdx = 0; AppIdx < NumAppRegions; ++AppIdx) { - if (!AppRegions[AppIdx].ShadowMergedWithPrev) { - if (UnmergedShadowCount == i) - break; - UnmergedShadowCount++; - } - } - if (AppIdx >= NumAppRegions || UnmergedShadowCount != i) - return false; - *Start = appToShadow(AppRegions[AppIdx].Start); - // The formula fails for the end itself. - *End = appToShadow(AppRegions[AppIdx].End - 1) + 1; - // Merge with adjacent shadow regions: - for (++AppIdx; AppIdx < NumAppRegions; ++AppIdx) { - if (!AppRegions[AppIdx].ShadowMergedWithPrev) - break; - *Start = Min(*Start, appToShadow(AppRegions[AppIdx].Start)); - *End = Max(*End, appToShadow(AppRegions[AppIdx].End - 1) + 1); - } - return true; -} - -ALWAYS_INLINE -bool isShadowMem(uptr Mem) { - // We assume this is not used on any critical performance path and so there's - // no need to hardcode the mapping results. - for (uptr i = 0; i < NumAppRegions; ++i) { - if (Mem >= appToShadow(AppRegions[i].Start) && - Mem < appToShadow(AppRegions[i].End - 1) + 1) - return true; - } - return false; -} - -} // namespace __esan - -#endif /* ESAN_SHADOW_H */ |