[msan] Block reports from interceptors during _Unwind_Backtrace
Summary:
I'm hitting a big recursive report from:
uninit on strlen ->
__msan::PrintWarningWithOrigin() ->
__msan::GetStackTrace() ->
__sanitizer::StackTrace::SlowUnwindStack() ->
_Unwind_Backtrace() ->
... libgcc calls ->
uninit on strlen() ->
... repeats
Reviewers: eugenis
Differential Revision: http://llvm-reviews.chandlerc.com/D497
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@176555 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/msan/msan.cc b/lib/msan/msan.cc
index ba27234..cfa0741 100644
--- a/lib/msan/msan.cc
+++ b/lib/msan/msan.cc
@@ -153,8 +153,11 @@
void GetStackTrace(StackTrace *stack, uptr max_s, uptr pc, uptr bp,
bool fast) {
- if (!fast)
+ if (!fast) {
+ // Block reports from our interceptors during _Unwind_Backtrace.
+ SymbolizerScope sym_scope;
return stack->SlowUnwindStack(pc, max_s);
+ }
uptr stack_top, stack_bottom;
GetCurrentStackBounds(&stack_top, &stack_bottom);
diff --git a/lib/msan/msan.h b/lib/msan/msan.h
index 2150c83..fae1ad5 100644
--- a/lib/msan/msan.h
+++ b/lib/msan/msan.h
@@ -50,6 +50,11 @@
void ExitSymbolizer();
bool IsInSymbolizer();
+struct SymbolizerScope {
+ SymbolizerScope() { EnterSymbolizer(); }
+ ~SymbolizerScope() { ExitSymbolizer(); }
+};
+
void MsanDie();
void PrintWarning(uptr pc, uptr bp);
void PrintWarningWithOrigin(uptr pc, uptr bp, u32 origin);
diff --git a/lib/msan/msan_report.cc b/lib/msan/msan_report.cc
index 16b13f6..df6990f 100644
--- a/lib/msan/msan_report.cc
+++ b/lib/msan/msan_report.cc
@@ -44,11 +44,6 @@
const char *End() { return Default(); }
};
-struct SymbolizerScope {
- SymbolizerScope() { EnterSymbolizer(); }
- ~SymbolizerScope() { ExitSymbolizer(); }
-};
-
static void PrintStack(const uptr *trace, uptr size) {
SymbolizerScope sym_scope;
StackTrace::PrintStack(trace, size, true, flags()->strip_path_prefix, 0);