diff options
author | Dmitry Vyukov <dvyukov@google.com> | 2016-09-22 13:42:02 +0000 |
---|---|---|
committer | Dmitry Vyukov <dvyukov@google.com> | 2016-09-22 13:42:02 +0000 |
commit | 16e13a58c700f4944ef908964d51e79699dbbd87 (patch) | |
tree | afa9f7bd468f9a5cb359a2d0f12f4ec204302762 /lib/tsan/rtl/tsan_platform.h | |
parent | 5042ecdfcbc09e87491222df05507dff67ad07ae (diff) |
tsan: support pie binaries on newer kernels
4.1+ Linux kernels map pie binaries at 0x55:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d1fd836dcf00d2028c700c7e44d2c23404062c90
Currently tsan does not support app memory at 0x55 (https://github.com/google/sanitizers/issues/503).
Older kernels also map pie binaries at 0x55 when ASLR is disables (most notably under gdb).
This change extends tsan mapping for linux/x86_64 to cover 0x554-0x568 app range and fixes both 4.1+ kernels and gdb.
This required to slightly shrink low and high app ranges and move heap. The mapping become even more non-linear, since now we xor lower bits. Now even a continuous app range maps to split, intermixed shadow ranges. This breaks ShadowToMemImpl as it assumes linear mapping at least within a continuous app range (however it turned out to be already broken at least on arm64/42-bit vma as uncovered by r281970). So also change ShadowToMemImpl to hopefully a more robust implementation that does not assume a linear mapping.
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@282152 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/tsan/rtl/tsan_platform.h')
-rw-r--r-- | lib/tsan/rtl/tsan_platform.h | 57 |
1 files changed, 35 insertions, 22 deletions
diff --git a/lib/tsan/rtl/tsan_platform.h b/lib/tsan/rtl/tsan_platform.h index 6ab26476d..903ff5be3 100644 --- a/lib/tsan/rtl/tsan_platform.h +++ b/lib/tsan/rtl/tsan_platform.h @@ -29,35 +29,42 @@ namespace __tsan { #if defined(__x86_64__) /* C/C++ on linux/x86_64 and freebsd/x86_64 -0000 0000 1000 - 0100 0000 0000: main binary and/or MAP_32BIT mappings -0100 0000 0000 - 0200 0000 0000: - -0200 0000 0000 - 1000 0000 0000: shadow +0000 0000 1000 - 0040 0000 0000: main binary and/or MAP_32BIT mappings (256GB) +0040 0000 0000 - 0100 0000 0000: - +0100 0000 0000 - 1000 0000 0000: shadow 1000 0000 0000 - 3000 0000 0000: - 3000 0000 0000 - 4000 0000 0000: metainfo (memory blocks and sync objects) -4000 0000 0000 - 6000 0000 0000: - +4000 0000 0000 - 5540 0000 0000: - +5540 0000 0000 - 5680 0000 0000: pie binaries without ASLR or on 4.1+ kernels +5680 0000 0000 - 6000 0000 0000: - 6000 0000 0000 - 6200 0000 0000: traces 6200 0000 0000 - 7d00 0000 0000: - -7d00 0000 0000 - 7e00 0000 0000: heap -7e00 0000 0000 - 7e80 0000 0000: - -7e80 0000 0000 - 8000 0000 0000: modules and main thread stack +7c40 0000 0000 - 7d40 0000 0000: heap +7d40 0000 0000 - 7ec0 0000 0000: - +7ec0 0000 0000 - 8000 0000 0000: modules and main thread stack */ struct Mapping { static const uptr kMetaShadowBeg = 0x300000000000ull; static const uptr kMetaShadowEnd = 0x400000000000ull; static const uptr kTraceMemBeg = 0x600000000000ull; static const uptr kTraceMemEnd = 0x620000000000ull; - static const uptr kShadowBeg = 0x020000000000ull; + static const uptr kShadowBeg = 0x010000000000ull; static const uptr kShadowEnd = 0x100000000000ull; - static const uptr kHeapMemBeg = 0x7d0000000000ull; - static const uptr kHeapMemEnd = 0x7e0000000000ull; + static const uptr kHeapMemBeg = 0x7c4000000000ull; + static const uptr kHeapMemEnd = 0x7d4000000000ull; static const uptr kLoAppMemBeg = 0x000000001000ull; - static const uptr kLoAppMemEnd = 0x010000000000ull; - static const uptr kHiAppMemBeg = 0x7e8000000000ull; + static const uptr kLoAppMemEnd = 0x004000000000ull; + static const uptr kMidAppMemBeg = 0x554000000000ull; + static const uptr kMidAppMemEnd = 0x568000000000ull; + static const uptr kMidShadowOff = 0x540000000000ull; + static const uptr kHiAppMemBeg = 0x7ec000000000ull; static const uptr kHiAppMemEnd = 0x800000000000ull; static const uptr kAppMemMsk = 0x7c0000000000ull; - static const uptr kAppMemXor = 0x020000000000ull; + static const uptr kAppMemXor = 0x028000000000ull; static const uptr kVdsoBeg = 0xf000000000000000ull; }; + +#define TSAN_MID_APP_RANGE 1 #elif defined(__mips64) /* C/C++ on linux/mips64 @@ -690,17 +697,23 @@ template<typename Mapping> uptr ShadowToMemImpl(uptr s) { DCHECK(IsShadowMem(s)); #ifndef SANITIZER_GO - if (s >= MemToShadow(Mapping::kLoAppMemBeg) - && s <= MemToShadow(Mapping::kLoAppMemEnd - 1)) - return (s / kShadowCnt) ^ Mapping::kAppMemXor; + // The shadow mapping is non-linear and we've lost some bits, so we don't have + // an easy way to restore the original app address. But the mapping is a + // bijection, so we try to restore the address as belonging to low/mid/high + // range consecutively and see if shadow->app->shadow mapping gives us the + // same address. + uptr p = (s / kShadowCnt) ^ Mapping::kAppMemXor; + if (MemToShadow(p) == s && + p >= Mapping::kLoAppMemBeg && p < Mapping::kLoAppMemEnd) + return p; # ifdef TSAN_MID_APP_RANGE - if (s >= MemToShadow(Mapping::kMidAppMemBeg) - && s <= MemToShadow(Mapping::kMidAppMemEnd - 1)) - return ((s / kShadowCnt) ^ Mapping::kAppMemXor) + Mapping::kMidShadowOff; + p = ((s / kShadowCnt) ^ Mapping::kAppMemXor) + Mapping::kMidShadowOff; + if (MemToShadow(p) == s && + p >= Mapping::kMidAppMemBeg && p < Mapping::kMidAppMemEnd) + return p; # endif - else - return ((s / kShadowCnt) ^ Mapping::kAppMemXor) | Mapping::kAppMemMsk; -#else + return ((s / kShadowCnt) ^ Mapping::kAppMemXor) | Mapping::kAppMemMsk; +#else // #ifndef SANITIZER_GO # ifndef SANITIZER_WINDOWS return (s & ~Mapping::kShadowBeg) / kShadowCnt; # else |