[compiler-rt] r190590 - [asan] Fix deadlock in stack unwinder on android/x86.
Evgeniy Stepanov
eugeni.stepanov at gmail.com
Thu Sep 12 01:16:28 PDT 2013
Author: eugenis
Date: Thu Sep 12 03:16:28 2013
New Revision: 190590
URL: http://llvm.org/viewvc/llvm-project?rev=190590&view=rev
Log:
[asan] Fix deadlock in stack unwinder on android/x86.
Fixes PR17116.
Patch by 林作健 (manjian2006 at gmail.com).
Modified:
compiler-rt/trunk/lib/asan/asan_stack.h
compiler-rt/trunk/lib/asan/asan_thread.h
compiler-rt/trunk/lib/lsan/lsan_common_linux.cc
Modified: compiler-rt/trunk/lib/asan/asan_stack.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_stack.h?rev=190590&r1=190589&r2=190590&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_stack.h (original)
+++ compiler-rt/trunk/lib/asan/asan_stack.h Thu Sep 12 03:16:28 2013
@@ -29,21 +29,21 @@ void PrintStack(StackTrace *stack);
// The pc will be in the position 0 of the resulting stack trace.
// The bp may refer to the current frame or to the caller's frame.
#if SANITIZER_WINDOWS
-#define GET_STACK_TRACE_WITH_PC_AND_BP(max_s, pc, bp, fast) \
- StackTrace stack; \
+#define GET_STACK_TRACE_WITH_PC_AND_BP(max_s, pc, bp, fast) \
+ StackTrace stack; \
GetStackTrace(&stack, max_s, pc, bp, 0, 0, fast)
#else
-#define GET_STACK_TRACE_WITH_PC_AND_BP(max_s, pc, bp, fast) \
- StackTrace stack; \
- { \
- uptr stack_top = 0, stack_bottom = 0; \
- AsanThread *t; \
- if (asan_inited && (t = GetCurrentThread())) { \
- stack_top = t->stack_top(); \
- stack_bottom = t->stack_bottom(); \
- } \
- GetStackTrace(&stack, max_s, pc, bp, \
- stack_top, stack_bottom, fast); \
+#define GET_STACK_TRACE_WITH_PC_AND_BP(max_s, pc, bp, fast) \
+ StackTrace stack; \
+ { \
+ AsanThread *t; \
+ stack.size = 0; \
+ if (asan_inited && (t = GetCurrentThread()) && !t->isUnwinding()) { \
+ uptr stack_top = t->stack_top(); \
+ uptr stack_bottom = t->stack_bottom(); \
+ ScopedUnwinding unwind_scope(t); \
+ GetStackTrace(&stack, max_s, pc, bp, stack_top, stack_bottom, fast); \
+ } \
}
#endif // SANITIZER_WINDOWS
Modified: compiler-rt/trunk/lib/asan/asan_thread.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_thread.h?rev=190590&r1=190589&r2=190590&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_thread.h (original)
+++ compiler-rt/trunk/lib/asan/asan_thread.h Thu Sep 12 03:16:28 2013
@@ -87,11 +87,17 @@ class AsanThread {
return fake_stack_;
}
+ // True is this thread is currently unwinding stack (i.e. collecting a stack
+ // trace). Used to prevent deadlocks on platforms where libc unwinder calls
+ // malloc internally. See PR17116 for more details.
+ bool isUnwinding() const { return unwinding; }
+ void setUnwinding(bool b) { unwinding = b; }
+
AsanThreadLocalMallocStorage &malloc_storage() { return malloc_storage_; }
AsanStats &stats() { return stats_; }
private:
- AsanThread() {}
+ AsanThread() : unwinding(false) {}
void SetThreadStackAndTls();
void ClearShadowForThreadStackAndTLS();
AsanThreadContext *context_;
@@ -105,6 +111,19 @@ class AsanThread {
FakeStack *fake_stack_;
AsanThreadLocalMallocStorage malloc_storage_;
AsanStats stats_;
+ bool unwinding;
+};
+
+// ScopedUnwinding is a scope for stacktracing member of a context
+class ScopedUnwinding {
+ public:
+ explicit ScopedUnwinding(AsanThread *t) : thread(t) {
+ t->setUnwinding(true);
+ }
+ ~ScopedUnwinding() { thread->setUnwinding(false); }
+
+ private:
+ AsanThread *thread;
};
struct CreateThreadContextArgs {
Modified: compiler-rt/trunk/lib/lsan/lsan_common_linux.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/lsan/lsan_common_linux.cc?rev=190590&r1=190589&r2=190590&view=diff
==============================================================================
--- compiler-rt/trunk/lib/lsan/lsan_common_linux.cc (original)
+++ compiler-rt/trunk/lib/lsan/lsan_common_linux.cc Thu Sep 12 03:16:28 2013
@@ -114,8 +114,9 @@ static void ProcessPlatformSpecificAlloc
chunk = GetUserBegin(chunk);
LsanMetadata m(chunk);
if (m.allocated() && m.tag() != kReachable) {
- if (linker->containsAddress(
- GetCallerPC(m.stack_trace_id(), param->stack_depot_reverse_map))) {
+ u32 stack_id = m.stack_trace_id();
+ if (!stack_id || linker->containsAddress(GetCallerPC(
+ stack_id, param->stack_depot_reverse_map))) {
m.set_tag(kReachable);
param->frontier->push_back(chunk);
}
More information about the llvm-commits
mailing list