[fuzzer] Fix threaded stack printing and nested mallocs

Summary: Nested mallocs are possible with internal symbolizer.

Reviewers: kcc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D39397

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@317034 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 19 insertions, 0 deletions

diff --git a/lib/fuzzer/FuzzerLoop.cpp b/lib/fuzzer/FuzzerLoop.cpp
index d3ac4ce7e..9cb580a30 100644
--- a/lib/fuzzer/FuzzerLoop.cpp
+++ b/lib/fuzzer/FuzzerLoop.cpp
@@ -19,6 +19,7 @@
 #include <algorithm>
 #include <cstring>
 #include <memory>
+#include <mutex>
 #include <set>
 
 #if defined(__has_include)
@@ -73,11 +74,24 @@ struct MallocFreeTracer {
 
 static MallocFreeTracer AllocTracer;
 
+static thread_local bool IsMallocFreeHookDisabled;
+static std::mutex MallocFreeStackMutex;
+
+struct MallocFreeHookDisabler {
+  MallocFreeHookDisabler() { IsMallocFreeHookDisabled = true; }
+  ~MallocFreeHookDisabler() { IsMallocFreeHookDisabled = false; }
+};
+
 ATTRIBUTE_NO_SANITIZE_MEMORY
 void MallocHook(const volatile void *ptr, size_t size) {
+  // Avoid nested hooks for mallocs/frees in sanitizer.
+  if (IsMallocFreeHookDisabled)
+    return;
+  MallocFreeHookDisabler Disable;
   size_t N = AllocTracer.Mallocs++;
   F->HandleMalloc(size);
   if (int TraceLevel = AllocTracer.TraceLevel) {
+    std::lock_guard<std::mutex> Lock(MallocFreeStackMutex);
     Printf("MALLOC[%zd] %p %zd\n", N, ptr, size);
     if (TraceLevel >= 2 && EF)
       EF->__sanitizer_print_stack_trace();
@@ -86,8 +100,13 @@ void MallocHook(const volatile void *ptr, size_t size) {
 
 ATTRIBUTE_NO_SANITIZE_MEMORY
 void FreeHook(const volatile void *ptr) {
+  // Avoid nested hooks for mallocs/frees in sanitizer.
+  if (IsMallocFreeHookDisabled)
+    return;
+  MallocFreeHookDisabler Disable;
   size_t N = AllocTracer.Frees++;
   if (int TraceLevel = AllocTracer.TraceLevel) {
+    std::lock_guard<std::mutex> Lock(MallocFreeStackMutex);
     Printf("FREE[%zd]   %p\n", N, ptr);
     if (TraceLevel >= 2 && EF)
       EF->__sanitizer_print_stack_trace();