diff options
Diffstat (limited to 'compiler-rt/lib/msan/msan_linux.cpp')
-rw-r--r-- | compiler-rt/lib/msan/msan_linux.cpp | 67 |
1 files changed, 54 insertions, 13 deletions
diff --git a/compiler-rt/lib/msan/msan_linux.cpp b/compiler-rt/lib/msan/msan_linux.cpp index c7ecb7cad566..cd2d9f5c720c 100644 --- a/compiler-rt/lib/msan/msan_linux.cpp +++ b/compiler-rt/lib/msan/msan_linux.cpp @@ -20,6 +20,9 @@ # include <signal.h> # include <stdio.h> # include <stdlib.h> +# if SANITIZER_LINUX +# include <sys/personality.h> +# endif # include <sys/resource.h> # include <sys/time.h> # include <unistd.h> @@ -43,11 +46,13 @@ void ReportMapRange(const char *descr, uptr beg, uptr size) { } } -static bool CheckMemoryRangeAvailability(uptr beg, uptr size) { +static bool CheckMemoryRangeAvailability(uptr beg, uptr size, bool verbose) { if (size > 0) { uptr end = beg + size - 1; if (!MemoryRangeIsAvailable(beg, end)) { - Printf("FATAL: Memory range 0x%zx - 0x%zx is not available.\n", beg, end); + if (verbose) + Printf("FATAL: Memory range 0x%zx - 0x%zx is not available.\n", beg, + end); return false; } } @@ -86,7 +91,7 @@ static void CheckMemoryLayoutSanity() { CHECK(addr_is_type(start, type)); CHECK(addr_is_type((start + end) / 2, type)); CHECK(addr_is_type(end - 1, type)); - if (type == MappingDesc::APP) { + if (type == MappingDesc::APP || type == MappingDesc::ALLOCATOR) { uptr addr = start; CHECK(MEM_IS_SHADOW(MEM_TO_SHADOW(addr))); CHECK(MEM_IS_ORIGIN(MEM_TO_ORIGIN(addr))); @@ -106,7 +111,7 @@ static void CheckMemoryLayoutSanity() { } } -bool InitShadow(bool init_origins) { +static bool InitShadow(bool init_origins, bool dry_run) { // Let user know mapping parameters first. VPrintf(1, "__msan_init %p\n", reinterpret_cast<void *>(&__msan_init)); for (unsigned i = 0; i < kMemoryLayoutSize; ++i) @@ -116,8 +121,9 @@ bool InitShadow(bool init_origins) { CheckMemoryLayoutSanity(); if (!MEM_IS_APP(&__msan_init)) { - Printf("FATAL: Code %p is out of application range. Non-PIE build?\n", - reinterpret_cast<void *>(&__msan_init)); + if (!dry_run) + Printf("FATAL: Code %p is out of application range. Non-PIE build?\n", + reinterpret_cast<void *>(&__msan_init)); return false; } @@ -138,20 +144,26 @@ bool InitShadow(bool init_origins) { bool protect = type == MappingDesc::INVALID || (!init_origins && type == MappingDesc::ORIGIN); CHECK(!(map && protect)); - if (!map && !protect) - CHECK(type == MappingDesc::APP); + if (!map && !protect) { + CHECK(type == MappingDesc::APP || type == MappingDesc::ALLOCATOR); + + if (dry_run && type == MappingDesc::ALLOCATOR && + !CheckMemoryRangeAvailability(start, size, !dry_run)) + return false; + } if (map) { - if (!CheckMemoryRangeAvailability(start, size)) + if (dry_run && !CheckMemoryRangeAvailability(start, size, !dry_run)) return false; - if (!MmapFixedSuperNoReserve(start, size, kMemoryLayout[i].name)) + if (!dry_run && + !MmapFixedSuperNoReserve(start, size, kMemoryLayout[i].name)) return false; - if (common_flags()->use_madv_dontdump) + if (!dry_run && common_flags()->use_madv_dontdump) DontDumpShadowMemory(start, size); } if (protect) { - if (!CheckMemoryRangeAvailability(start, size)) + if (dry_run && !CheckMemoryRangeAvailability(start, size, !dry_run)) return false; - if (!ProtectMemoryRange(start, size, kMemoryLayout[i].name)) + if (!dry_run && !ProtectMemoryRange(start, size, kMemoryLayout[i].name)) return false; } } @@ -159,6 +171,35 @@ bool InitShadow(bool init_origins) { return true; } +bool InitShadowWithReExec(bool init_origins) { + // Start with dry run: check layout is ok, but don't print warnings because + // warning messages will cause tests to fail (even if we successfully re-exec + // after the warning). + bool success = InitShadow(__msan_get_track_origins(), true); + if (!success) { +# if SANITIZER_LINUX + // Perhaps ASLR entropy is too high. If ASLR is enabled, re-exec without it. + int old_personality = personality(0xffffffff); + bool aslr_on = + (old_personality != -1) && ((old_personality & ADDR_NO_RANDOMIZE) == 0); + + if (aslr_on) { + VReport(1, + "WARNING: MemorySanitizer: memory layout is incompatible, " + "possibly due to high-entropy ASLR.\n" + "Re-execing with fixed virtual address space.\n" + "N.B. reducing ASLR entropy is preferable.\n"); + CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1); + ReExec(); + } +# endif + } + + // The earlier dry run didn't actually map or protect anything. Run again in + // non-dry run mode. + return success && InitShadow(__msan_get_track_origins(), false); +} + static void MsanAtExit(void) { if (flags()->print_stats && (flags()->atexit || msan_report_count > 0)) ReportStats(); |