[sanitizer] Don't run malloc hooks for stacktraces

Usually when we generated stacktraces the process is in error state, so
running hooks may crash the process and prevent meaningfull error report.

Symbolizer, unwinder and pthread are potential source of mallocs.

https://b.corp.google.com/issues/228110771

Reviewed By: kda

Differential Revision: https://reviews.llvm.org/D123566

compiler-rt/lib/msan/msan_allocator.cpp

@@ -194,16 +194,19 @@ static void *MsanAllocate(StackTrace *stack, uptr size, uptr alignment,
       __msan_set_origin(allocated, size, o.raw_id());
     }
   }
-  UnpoisonParam(2);
-  RunMallocHooks(allocated, size);
+  if (!IsInSymbolizerOrUnwider()) {
+    UnpoisonParam(2);
+    RunMallocHooks(allocated, size);
+  }
   return allocated;
 }
 
 void MsanDeallocate(StackTrace *stack, void *p) {
   CHECK(p);
-  UnpoisonParam(1);
-  RunFreeHooks(p);
-
+  if (!IsInSymbolizerOrUnwider()) {
+    UnpoisonParam(1);
+    RunFreeHooks(p);
+  }
   Metadata *meta = reinterpret_cast<Metadata *>(allocator.GetMetaData(p));
   uptr size = meta->requested_size;
   meta->requested_size = 0;

compiler-rt/lib/sanitizer_common/sanitizer_common.cpp

@@ -310,7 +310,23 @@ struct MallocFreeHook {
 
 static MallocFreeHook MFHooks[kMaxMallocFreeHooks];
 
+#if !SANITIZER_SUPPORTS_THREADLOCAL || SANITIZER_GO || SANITIZER_MAC || \
+    SANITIZER_ANDROID
+// FIXME: Prevent hooks on other platforms.
+static constexpr int disable_malloc_hooks = 0;
+ScopedDisableMallocHooks::ScopedDisableMallocHooks() {}
+ScopedDisableMallocHooks::~ScopedDisableMallocHooks() {}
+#else
+static THREADLOCAL int disable_malloc_hooks = 0;
+ScopedDisableMallocHooks::ScopedDisableMallocHooks() { ++disable_malloc_hooks; }
+ScopedDisableMallocHooks::~ScopedDisableMallocHooks() {
+  --disable_malloc_hooks;
+}
+#endif
+
 void RunMallocHooks(void *ptr, uptr size) {
+  if (disable_malloc_hooks)
+    return;
   __sanitizer_malloc_hook(ptr, size);
   for (int i = 0; i < kMaxMallocFreeHooks; i++) {
     auto hook = MFHooks[i].malloc_hook;
@@ -321,6 +337,8 @@ void RunMallocHooks(void *ptr, uptr size) {
 }
 
 void RunFreeHooks(void *ptr) {
+  if (disable_malloc_hooks)
+    return;
   __sanitizer_free_hook(ptr);
   for (int i = 0; i < kMaxMallocFreeHooks; i++) {
     auto hook = MFHooks[i].free_hook;

compiler-rt/lib/sanitizer_common/sanitizer_common.h

@@ -170,9 +170,18 @@ void SetShadowRegionHugePageMode(uptr addr, uptr length);
 bool DontDumpShadowMemory(uptr addr, uptr length);
 // Check if the built VMA size matches the runtime one.
 void CheckVMASize();
+
 void RunMallocHooks(void *ptr, uptr size);
 void RunFreeHooks(void *ptr);
 
+// Prevents RunMallocHooks and RunFreeHooks. Can be used in places where hooks
+// are undesirable, like in symbolizer or unwinder.
+class ScopedDisableMallocHooks {
+ public:
+  ScopedDisableMallocHooks();
+  ~ScopedDisableMallocHooks();
+};
+
 class ReservedAddressRange {
  public:
   uptr Init(uptr size, const char *name = nullptr, uptr fixed_addr = 0);

compiler-rt/lib/sanitizer_common/sanitizer_fuchsia.cpp

@@ -75,6 +75,7 @@ void Abort() { abort(); }
 int Atexit(void (*function)(void)) { return atexit(function); }
 
 void GetThreadStackTopAndBottom(bool, uptr *stack_top, uptr *stack_bottom) {
+  ScopedDisableMallocHooks disable_hooks;  // pthread can malloc.
   pthread_attr_t attr;
   CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0);
   void *base;

compiler-rt/lib/sanitizer_common/sanitizer_linux_libcdep.cpp

@@ -103,6 +103,7 @@ void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
                                 uptr *stack_bottom) {
   CHECK(stack_top);
   CHECK(stack_bottom);
+  ScopedDisableMallocHooks disable_hooks;  // pthread can malloc.
   if (at_initialization) {
     // This is the main thread. Libpthread may not be initialized yet.
     struct rlimit rl;

compiler-rt/lib/sanitizer_common/sanitizer_mac.cpp

@@ -410,6 +410,7 @@ void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
                                 uptr *stack_bottom) {
   CHECK(stack_top);
   CHECK(stack_bottom);
+  ScopedDisableMallocHooks disable_hooks;  // pthread can malloc.
   uptr stacksize = pthread_get_stacksize_np(pthread_self());
   // pthread_get_stacksize_np() returns an incorrect stack size for the main
   // thread on Mavericks. See

compiler-rt/lib/sanitizer_common/sanitizer_symbolizer.h

@@ -212,6 +212,8 @@ class Symbolizer final {
     ~SymbolizerScope();
    private:
     const Symbolizer *sym_;
+
+    ScopedDisableMallocHooks disable_hooks_;  // Symbolizer can malloc.
   };
 };
 

compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_markup.cpp

@@ -126,6 +126,7 @@ _Unwind_Reason_Code Unwind_Trace(struct _Unwind_Context *ctx, void *param) {
 void BufferedStackTrace::UnwindSlow(uptr pc, u32 max_depth) {
   CHECK_GE(max_depth, 2);
   size = 0;
+  ScopedDisableMallocHooks disable_hooks;  // libunwind can malloc.
   UnwindTraceArg arg = {this, Min(max_depth + 1, kStackTraceMax)};
   _Unwind_Backtrace(Unwind_Trace, &arg);
   CHECK_GT(size, 0);

compiler-rt/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cpp

@@ -126,6 +126,7 @@ void SanitizerInitializeUnwinder() {
 void BufferedStackTrace::UnwindSlow(uptr pc, u32 max_depth) {
   CHECK_GE(max_depth, 2);
   size = 0;
+  ScopedDisableMallocHooks disable_hooks;  // libunwind can malloc.
   UnwindTraceArg arg = {this, Min(max_depth + 1, kStackTraceMax)};
   _Unwind_Backtrace(Unwind_Trace, &arg);
   // We need to pop a few frames so that pc is on top.
@@ -156,6 +157,7 @@ void BufferedStackTrace::UnwindSlow(uptr pc, void *context, u32 max_depth) {
     return;
   }
 
+  ScopedDisableMallocHooks disable_hooks;  // Maybe unneeded, but won't hurt.
   void *map = acquire_my_map_info_list();
   CHECK(map);
   InternalMmapVector<backtrace_frame_t> frames(kStackTraceMax);

compiler-rt/test/sanitizer_common/TestCases/malloc_hook_skip.cpp

@@ -0,0 +1,37 @@
+// RUN: %clangxx -O0 -g %s -o %t && %run %t
+
+// Test requires platform with thread local support with no dependency on malloc.
+// UNSUPPORTED: android
+// UNSUPPORTED: ios
+
+#include <assert.h>
+#include <sanitizer/allocator_interface.h>
+#include <sanitizer/coverage_interface.h>
+#include <stdlib.h>
+
+static int hooks;
+extern "C" {
+
+void __sanitizer_malloc_hook(const volatile void *ptr, size_t sz) { ++hooks; }
+
+void __sanitizer_free_hook(const volatile void *ptr) { ++hooks; }
+
+} // extern "C"
+
+void MallocHook(const volatile void *ptr, size_t sz) { ++hooks; }
+void FreeHook(const volatile void *ptr) { ++hooks; }
+
+int main() {
+  int before;
+
+  before = hooks;
+  __sanitizer_print_stack_trace();
+  assert(before == hooks);
+
+  __sanitizer_install_malloc_and_free_hooks(MallocHook, FreeHook);
+  before = hooks;
+  __sanitizer_print_stack_trace();
+  assert(before == hooks);
+
+  return 0;
+}