[compiler-rt] [tsan] Unwind for CHECK according to fast_unwind_on_fatal (PR #117470)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: Vitaly Buka (vitalybuka)

<details>
<summary>Changes</summary>

It's needed for #<!-- -->116409, which hangs with slow
unwind.


---
Full diff: https://github.com/llvm/llvm-project/pull/117470.diff


3 Files Affected:

- (modified) compiler-rt/lib/tsan/rtl/tsan_rtl.cpp (+2-1) 
- (modified) compiler-rt/lib/tsan/rtl/tsan_rtl.h (+1-1) 
- (modified) compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp (+5-5) 


``````````diff
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl.cpp b/compiler-rt/lib/tsan/rtl/tsan_rtl.cpp
index 5a2d39cd30607f..c83efec8eaca2c 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl.cpp
@@ -673,7 +673,8 @@ void CheckUnwind() {
   thr->ignore_reads_and_writes++;
   atomic_store_relaxed(&thr->in_signal_handler, 0);
 #endif
-  PrintCurrentStackSlow(StackTrace::GetCurrentPc());
+  PrintCurrentStack(StackTrace::GetCurrentPc(),
+                    common_flags()->fast_unwind_on_fatal);
 }
 
 bool is_initialized;
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl.h b/compiler-rt/lib/tsan/rtl/tsan_rtl.h
index f48be8e0a4fe08..49bee9c67d3030 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl.h
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl.h
@@ -514,7 +514,7 @@ bool IsExpectedReport(uptr addr, uptr size);
 StackID CurrentStackId(ThreadState *thr, uptr pc);
 ReportStack *SymbolizeStackId(StackID stack_id);
 void PrintCurrentStack(ThreadState *thr, uptr pc);
-void PrintCurrentStackSlow(uptr pc);  // uses libunwind
+void PrintCurrentStack(uptr pc, bool fast);  // may uses libunwind
 MBlock *JavaHeapBlock(uptr addr, uptr *start);
 
 void Initialize(ThreadState *thr);
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp b/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp
index 0311df553fdd0a..51a98e2f2d5e75 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp
@@ -828,18 +828,18 @@ void PrintCurrentStack(ThreadState *thr, uptr pc) {
   PrintStack(SymbolizeStack(trace));
 }
 
-// Always inlining PrintCurrentStackSlow, because LocatePcInTrace assumes
+// Always inlining PrintCurrentStack, because LocatePcInTrace assumes
 // __sanitizer_print_stack_trace exists in the actual unwinded stack, but
-// tail-call to PrintCurrentStackSlow breaks this assumption because
+// tail-call to PrintCurrentStack breaks this assumption because
 // __sanitizer_print_stack_trace disappears after tail-call.
 // However, this solution is not reliable enough, please see dvyukov's comment
 // http://reviews.llvm.org/D19148#406208
 // Also see PR27280 comment 2 and 3 for breaking examples and analysis.
-ALWAYS_INLINE USED void PrintCurrentStackSlow(uptr pc) {
+ALWAYS_INLINE USED void PrintCurrentStack(uptr pc, bool fast) {
 #if !SANITIZER_GO
   uptr bp = GET_CURRENT_FRAME();
   auto *ptrace = New<BufferedStackTrace>();
-  ptrace->Unwind(pc, bp, nullptr, false);
+  ptrace->Unwind(pc, bp, nullptr, fast);
 
   for (uptr i = 0; i < ptrace->size / 2; i++) {
     uptr tmp = ptrace->trace_buffer[i];
@@ -857,6 +857,6 @@ using namespace __tsan;
 extern "C" {
 SANITIZER_INTERFACE_ATTRIBUTE
 void __sanitizer_print_stack_trace() {
-  PrintCurrentStackSlow(StackTrace::GetCurrentPc());
+  PrintCurrentStack(StackTrace::GetCurrentPc(), false);
 }
 }  // extern "C"

``````````

</details>


https://github.com/llvm/llvm-project/pull/117470