From 0bee2d927c97454e629b0789c7f4e3d509cf4178 Mon Sep 17 00:00:00 2001 From: Evgeniy Stepanov Date: Thu, 8 Oct 2015 21:35:34 +0000 Subject: [PATCH] New MSan mapping layout (compiler-rt part). This is an implementation of https://github.com/google/sanitizers/issues/579 It has a number of advantages over the current mapping: * Works for non-PIE executables. * Does not require ASLR; as a consequence, debugging MSan programs in gdb no longer requires "set disable-randomization off". * Supports linux kernels >=4.1.2. * The code is marginally faster and smaller. This is an ABI break. We never really promised ABI stability, but this patch includes a courtesy escape hatch: a compile-time macro that reverts back to the old mapping layout. git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@249754 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/msan/msan.h | 23 ++++++++++++++++++++++ lib/msan/msan_allocator.cc | 8 +++++++- test/msan/mmap.cc | 4 +++- test/msan/strlen_of_shadow.cc | 2 +- .../TestCases/Posix/decorate_proc_maps.cc | 4 ++-- 5 files changed, 36 insertions(+), 5 deletions(-) diff --git a/lib/msan/msan.h b/lib/msan/msan.h index 3776fa9..2d77983 100644 --- a/lib/msan/msan.h +++ b/lib/msan/msan.h @@ -135,6 +135,7 @@ const MappingDesc kMemoryLayout[] = { #elif SANITIZER_LINUX && SANITIZER_WORDSIZE == 64 +#ifdef MSAN_LINUX_X86_64_OLD_MAPPING // Requries PIE binary and ASLR enabled. // Main thread stack and DSOs at 0x7f0000000000 (sometimes 0x7e0000000000). // Heap at 0x600000000000. @@ -146,6 +147,28 @@ const MappingDesc kMemoryLayout[] = { #define MEM_TO_SHADOW(mem) (((uptr)(mem)) & ~0x400000000000ULL) #define SHADOW_TO_ORIGIN(mem) (((uptr)(mem)) + 0x200000000000ULL) +#else // MSAN_LINUX_X86_64_OLD_MAPPING +// All of the following configurations are supported. +// ASLR disabled: main executable and DSOs at 0x555550000000 +// PIE and ASLR: main executable and DSOs at 0x7f0000000000 +// non-PIE: main executable below 0x100000000, DSOs at 0x7f0000000000 +// Heap at 0x700000000000. +const MappingDesc kMemoryLayout[] = { + {0x000000000000ULL, 0x010000000000ULL, MappingDesc::APP, "app-1"}, + {0x010000000000ULL, 0x100000000000ULL, MappingDesc::SHADOW, "shadow-2"}, + {0x100000000000ULL, 0x110000000000ULL, MappingDesc::INVALID, "invalid"}, + {0x110000000000ULL, 0x200000000000ULL, MappingDesc::ORIGIN, "origin-2"}, + {0x200000000000ULL, 0x300000000000ULL, MappingDesc::SHADOW, "shadow-3"}, + {0x300000000000ULL, 0x400000000000ULL, MappingDesc::ORIGIN, "origin-3"}, + {0x400000000000ULL, 0x500000000000ULL, MappingDesc::INVALID, "invalid"}, + {0x500000000000ULL, 0x510000000000ULL, MappingDesc::SHADOW, "shadow-1"}, + {0x510000000000ULL, 0x600000000000ULL, MappingDesc::APP, "app-2"}, + {0x600000000000ULL, 0x610000000000ULL, MappingDesc::ORIGIN, "origin-1"}, + {0x610000000000ULL, 0x700000000000ULL, MappingDesc::INVALID, "invalid"}, + {0x700000000000ULL, 0x800000000000ULL, MappingDesc::APP, "app-3"}}; +#define MEM_TO_SHADOW(mem) (((uptr)(mem)) ^ 0x500000000000ULL) +#define SHADOW_TO_ORIGIN(mem) (((uptr)(mem)) + 0x100000000000ULL) +#endif // MSAN_LINUX_X86_64_OLD_MAPPING #else #error "Unsupported platform" diff --git a/lib/msan/msan_allocator.cc b/lib/msan/msan_allocator.cc index 865a458..b7d3947 100644 --- a/lib/msan/msan_allocator.cc +++ b/lib/msan/msan_allocator.cc @@ -49,15 +49,21 @@ struct MsanMapUnmapCallback { typedef SizeClassAllocator32<0, SANITIZER_MMAP_RANGE_SIZE, sizeof(Metadata), SizeClassMap, kRegionSizeLog, ByteMap, MsanMapUnmapCallback> PrimaryAllocator; + #elif defined(__x86_64__) +#if SANITIZER_LINUX && !defined(MSAN_LINUX_X86_64_OLD_MAPPING) + static const uptr kAllocatorSpace = 0x700000000000ULL; +#else static const uptr kAllocatorSpace = 0x600000000000ULL; - static const uptr kAllocatorSize = 0x80000000000; // 8T. +#endif + static const uptr kAllocatorSize = 0x80000000000; // 8T. static const uptr kMetadataSize = sizeof(Metadata); static const uptr kMaxAllowedMallocSize = 8UL << 30; typedef SizeClassAllocator64 PrimaryAllocator; + #elif defined(__powerpc64__) static const uptr kAllocatorSpace = 0x300000000000; static const uptr kAllocatorSize = 0x020000000000; // 2T diff --git a/test/msan/mmap.cc b/test/msan/mmap.cc index 250ce34..962836c 100644 --- a/test/msan/mmap.cc +++ b/test/msan/mmap.cc @@ -15,7 +15,9 @@ bool AddrIsApp(void *p) { #if defined(__FreeBSD__) && defined(__x86_64__) return addr < 0x010000000000ULL || addr >= 0x600000000000ULL; #elif defined(__x86_64__) - return addr >= 0x600000000000ULL; + return (addr >= 0x000000000000ULL && addr < 0x010000000000ULL) || + (addr >= 0x510000000000ULL && addr < 0x600000000000ULL) || + (addr >= 0x700000000000ULL && addr < 0x800000000000ULL); #elif defined(__mips64) return addr >= 0x00e000000000ULL; #elif defined(__powerpc64__) diff --git a/test/msan/strlen_of_shadow.cc b/test/msan/strlen_of_shadow.cc index fee9223..0594f00 100644 --- a/test/msan/strlen_of_shadow.cc +++ b/test/msan/strlen_of_shadow.cc @@ -12,7 +12,7 @@ const char *mem_to_shadow(const char *p) { #if defined(__x86_64__) - return (char *)((uintptr_t)p & ~0x400000000000ULL); + return (char *)((uintptr_t)p ^ 0x500000000000ULL); #elif defined (__mips64) return (char *)((uintptr_t)p & ~0x4000000000ULL); #elif defined(__powerpc64__) diff --git a/test/sanitizer_common/TestCases/Posix/decorate_proc_maps.cc b/test/sanitizer_common/TestCases/Posix/decorate_proc_maps.cc index 8744c3f..36d4df5 100644 --- a/test/sanitizer_common/TestCases/Posix/decorate_proc_maps.cc +++ b/test/sanitizer_common/TestCases/Posix/decorate_proc_maps.cc @@ -47,8 +47,8 @@ int main(void) { // CHECK-asan: rw-p {{.*}} [high shadow] // CHECK-msan: ---p {{.*}} [invalid] -// CHECK-msan: rw-p {{.*}} [shadow] -// CHECK-msan: ---p {{.*}} [origin] +// CHECK-msan: rw-p {{.*}} [shadow{{.*}}] +// CHECK-msan: ---p {{.*}} [origin{{.*}}] // CHECK-tsan: rw-p {{.*}} [shadow] // CHECK-tsan: rw-p {{.*}} [meta shadow] -- 2.6.1