Index: compiler-rt/lib/asan/asan_thread.cc =================================================================== --- compiler-rt/lib/asan/asan_thread.cc +++ compiler-rt/lib/asan/asan_thread.cc @@ -223,9 +223,11 @@ atomic_store(&stack_switching_, false, memory_order_release); CHECK_EQ(this->stack_size(), 0U); SetThreadStackAndTls(options); - CHECK_GT(this->stack_size(), 0U); - CHECK(AddrIsInMem(stack_bottom_)); - CHECK(AddrIsInMem(stack_top_ - 1)); + if (stack_top_ != stack_bottom_) { + CHECK_GT(this->stack_size(), 0U); + CHECK(AddrIsInMem(stack_bottom_)); + CHECK(AddrIsInMem(stack_top_ - 1)); + } ClearShadowForThreadStackAndTLS(); fake_stack_ = nullptr; if (__asan_option_detect_stack_use_after_return) @@ -295,14 +297,17 @@ tls_end_ = tls_begin_ + tls_size; dtls_ = DTLS_Get(); - int local; - CHECK(AddrIsInStack((uptr)&local)); + if (stack_top_ != stack_bottom_) { + int local; + CHECK(AddrIsInStack((uptr)&local)); + } } #endif // !SANITIZER_FUCHSIA && !SANITIZER_RTEMS void AsanThread::ClearShadowForThreadStackAndTLS() { - PoisonShadow(stack_bottom_, stack_top_ - stack_bottom_, 0); + if (stack_top_ != stack_bottom_) + PoisonShadow(stack_bottom_, stack_top_ - stack_bottom_, 0); if (tls_begin_ != tls_end_) { uptr tls_begin_aligned = RoundDownTo(tls_begin_, SHADOW_GRANULARITY); uptr tls_end_aligned = RoundUpTo(tls_end_, SHADOW_GRANULARITY); @@ -314,6 +319,9 @@ bool AsanThread::GetStackFrameAccessByAddr(uptr addr, StackFrameAccess *access) { + if (stack_top_ == stack_bottom_) + return false; + uptr bottom = 0; if (AddrIsInStack(addr)) { bottom = stack_bottom(); Index: compiler-rt/lib/hwasan/hwasan_thread.cc =================================================================== --- compiler-rt/lib/hwasan/hwasan_thread.cc +++ compiler-rt/lib/hwasan/hwasan_thread.cc @@ -43,27 +43,18 @@ // ScopedTaggingDisable needs GetCurrentThread to be set up. ScopedTaggingDisabler disabler; - // If this process is "init" (pid 1), /proc may not be mounted yet. - if (IsMainThread() && !FileExists("/proc/self/maps")) { - stack_top_ = stack_bottom_ = 0; - tls_begin_ = tls_end_ = 0; - } else { - uptr tls_size; - uptr stack_size; - GetThreadStackAndTls(IsMainThread(), &stack_bottom_, &stack_size, - &tls_begin_, &tls_size); - stack_top_ = stack_bottom_ + stack_size; - tls_end_ = tls_begin_ + tls_size; - + uptr tls_size; + uptr stack_size; + GetThreadStackAndTls(IsMainThread(), &stack_bottom_, &stack_size, &tls_begin_, + &tls_size); + stack_top_ = stack_bottom_ + stack_size; + tls_end_ = tls_begin_ + tls_size; + + if (stack_bottom_) { int local; CHECK(AddrIsInStack((uptr)&local)); CHECK(MemIsApp(stack_bottom_)); CHECK(MemIsApp(stack_top_ - 1)); - - if (stack_bottom_) { - CHECK(MemIsApp(stack_bottom_)); - CHECK(MemIsApp(stack_top_ - 1)); - } } if (flags()->verbose_threads) { Index: compiler-rt/lib/sanitizer_common/sanitizer_flags.inc =================================================================== --- compiler-rt/lib/sanitizer_common/sanitizer_flags.inc +++ compiler-rt/lib/sanitizer_common/sanitizer_flags.inc @@ -243,3 +243,6 @@ COMMON_FLAG(bool, detect_write_exec, false, "If true, triggers warning when writable-executable pages requests " "are being made") +COMMON_FLAG(bool, test_only_emulate_no_memorymap, false, + "TEST ONLY fail to read memory mappings to emulate sanitized " + "\"init\"") Index: compiler-rt/lib/sanitizer_common/sanitizer_linux.cc =================================================================== --- compiler-rt/lib/sanitizer_common/sanitizer_linux.cc +++ compiler-rt/lib/sanitizer_common/sanitizer_linux.cc @@ -453,6 +453,8 @@ // ----------------- sanitizer_common.h bool FileExists(const char *filename) { + if (ShouldMockFailureToOpen(filename)) + return false; struct stat st; #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS if (internal_syscall(SYSCALL(newfstatat), AT_FDCWD, filename, &st, 0)) @@ -1008,6 +1010,8 @@ // Firstly check if there are writable segments // mapped to top gigabyte (e.g. stack). MemoryMappingLayout proc_maps(/*cache_enabled*/true); + if (proc_maps.Error()) + return 0; MemoryMappedSegment segment; while (proc_maps.Next(&segment)) { if ((segment.end >= 3 * gbyte) && segment.IsWritable()) return 0; Index: compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cc =================================================================== --- compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cc +++ compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cc @@ -100,6 +100,10 @@ // Find the mapping that contains a stack variable. MemoryMappingLayout proc_maps(/*cache_enabled*/true); + if (proc_maps.Error()) { + *stack_top = *stack_bottom = 0; + return; + } MemoryMappedSegment segment; uptr prev_end = 0; while (proc_maps.Next(&segment)) { Index: compiler-rt/lib/sanitizer_common/sanitizer_mac.cc =================================================================== --- compiler-rt/lib/sanitizer_common/sanitizer_mac.cc +++ compiler-rt/lib/sanitizer_common/sanitizer_mac.cc @@ -282,6 +282,8 @@ // ----------------- sanitizer_common.h bool FileExists(const char *filename) { + if (ShouldMockFailureToOpen(filename)) + return false; struct stat st; if (stat(filename, &st)) return false; Index: compiler-rt/lib/sanitizer_common/sanitizer_posix.h =================================================================== --- compiler-rt/lib/sanitizer_common/sanitizer_posix.h +++ compiler-rt/lib/sanitizer_common/sanitizer_posix.h @@ -103,6 +103,8 @@ // Move the fd out of {0, 1, 2} range. fd_t ReserveStandardFds(fd_t fd); +bool ShouldMockFailureToOpen(const char *path); + } // namespace __sanitizer #endif // SANITIZER_POSIX_H Index: compiler-rt/lib/sanitizer_common/sanitizer_posix.cc =================================================================== --- compiler-rt/lib/sanitizer_common/sanitizer_posix.cc +++ compiler-rt/lib/sanitizer_common/sanitizer_posix.cc @@ -18,6 +18,7 @@ #include "sanitizer_common.h" #include "sanitizer_file.h" +#include "sanitizer_flags.h" #include "sanitizer_libc.h" #include "sanitizer_posix.h" #include "sanitizer_procmaps.h" @@ -157,6 +158,8 @@ #endif fd_t OpenFile(const char *filename, FileAccessMode mode, error_t *errno_p) { + if (ShouldMockFailureToOpen(filename)) + return kInvalidFd; int flags; switch (mode) { case RdOnly: flags = O_RDONLY; break; @@ -230,6 +233,8 @@ // memory). bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) { MemoryMappingLayout proc_maps(/*cache_enabled*/true); + if (proc_maps.Error()) + return true; // and hope for the best MemoryMappedSegment segment; while (proc_maps.Next(&segment)) { if (segment.start == segment.end) continue; // Empty range. @@ -334,6 +339,11 @@ return fd; } +bool ShouldMockFailureToOpen(const char *path) { + return common_flags()->test_only_emulate_no_memorymap && + internal_strncmp(path, "/proc/", 6) == 0; +} + } // namespace __sanitizer #endif // SANITIZER_POSIX Index: compiler-rt/lib/sanitizer_common/sanitizer_procmaps.h =================================================================== --- compiler-rt/lib/sanitizer_common/sanitizer_procmaps.h +++ compiler-rt/lib/sanitizer_common/sanitizer_procmaps.h @@ -70,6 +70,7 @@ explicit MemoryMappingLayout(bool cache_enabled); ~MemoryMappingLayout(); bool Next(MemoryMappedSegment *segment); + bool Error() const; void Reset(); // In some cases, e.g. when running under a sandbox on Linux, ASan is unable // to obtain the memory mappings. It should fall back to pre-cached data Index: compiler-rt/lib/sanitizer_common/sanitizer_procmaps_bsd.cc =================================================================== --- compiler-rt/lib/sanitizer_common/sanitizer_procmaps_bsd.cc +++ compiler-rt/lib/sanitizer_common/sanitizer_procmaps_bsd.cc @@ -99,6 +99,7 @@ } bool MemoryMappingLayout::Next(MemoryMappedSegment *segment) { + CHECK(!Error()); // can not fail char *last = data_.proc_self_maps.data + data_.proc_self_maps.len; if (data_.current >= last) return false; Index: compiler-rt/lib/sanitizer_common/sanitizer_procmaps_common.cc =================================================================== --- compiler-rt/lib/sanitizer_common/sanitizer_procmaps_common.cc +++ compiler-rt/lib/sanitizer_common/sanitizer_procmaps_common.cc @@ -80,12 +80,14 @@ ReadProcMaps(&data_.proc_self_maps); if (cache_enabled && data_.proc_self_maps.mmaped_size == 0) LoadFromCache(); - CHECK_GT(data_.proc_self_maps.mmaped_size, 0); - CHECK_GT(data_.proc_self_maps.len, 0); Reset(); } +bool MemoryMappingLayout::Error() const { + return data_.current == nullptr; +} + MemoryMappingLayout::~MemoryMappingLayout() { // Only unmap the buffer if it is different from the cached one. Otherwise // it will be unmapped when the cache is refreshed. Index: compiler-rt/lib/sanitizer_common/sanitizer_procmaps_linux.cc =================================================================== --- compiler-rt/lib/sanitizer_common/sanitizer_procmaps_linux.cc +++ compiler-rt/lib/sanitizer_common/sanitizer_procmaps_linux.cc @@ -31,6 +31,7 @@ } bool MemoryMappingLayout::Next(MemoryMappedSegment *segment) { + if (Error()) return false; // simulate empty maps char *last = data_.proc_self_maps.data + data_.proc_self_maps.len; if (data_.current >= last) return false; char *next_line = Index: compiler-rt/lib/sanitizer_common/sanitizer_procmaps_solaris.cc =================================================================== --- compiler-rt/lib/sanitizer_common/sanitizer_procmaps_solaris.cc +++ compiler-rt/lib/sanitizer_common/sanitizer_procmaps_solaris.cc @@ -21,11 +21,16 @@ namespace __sanitizer { void ReadProcMaps(ProcSelfMapsBuff *proc_maps) { - ReadFileToBuffer("/proc/self/xmap", &proc_maps->data, &proc_maps->mmaped_size, - &proc_maps->len); + if (!ReadFileToBuffer("/proc/self/xmap", &proc_maps->data, + &proc_maps->mmaped_size, &proc_maps->len)) { + proc_maps->data = nullptr; + proc_maps->mmaped_size = 0; + proc_maps->len = 0; + } } bool MemoryMappingLayout::Next(MemoryMappedSegment *segment) { + if (Error()) return false; // simulate empty maps char *last = data_.proc_self_maps.data + data_.proc_self_maps.len; if (data_.current >= last) return false; Index: compiler-rt/test/asan/TestCases/Posix/no-fd.cc =================================================================== --- compiler-rt/test/asan/TestCases/Posix/no-fd.cc +++ compiler-rt/test/asan/TestCases/Posix/no-fd.cc @@ -9,6 +9,10 @@ #include #include +extern "C" const char *__asan_default_options() { + return "test_only_emulate_no_memorymap=1"; +} + void parent(int argc, char **argv) { fprintf(stderr, "hello\n"); // CHECK: hello