[compiler-rt] [asan] Add experimental 'track_poison' flag (PR #133175)

[Thurston Dang via llvm-commits]

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@@ -10,15 +10,64 @@
 //
 // Shadow memory poisoning by ASan RTL and by user application.
 //===----------------------------------------------------------------------===//
+#ifndef ASAN_POISONING_H
+#define ASAN_POISONING_H
 
 #include "asan_interceptors.h"
 #include "asan_internal.h"
 #include "asan_mapping.h"
 #include "sanitizer_common/sanitizer_flags.h"
 #include "sanitizer_common/sanitizer_platform.h"
+#include "sanitizer_common/sanitizer_ring_buffer.h"
+
+// For platforms which support slow unwinder only, we restrict the store context
+// size to 1, basically only storing the current pc. We do this because the slow
+// unwinder which is based on libunwind is not async signal safe and causes
+// random freezes in forking applications as well as in signal handlers.
+#define GET_STORE_STACK_TRACE_PC_BP(pc, bp)                            \
+  UNINITIALIZED BufferedStackTrace stack;                              \
+  int max_stack = 16;                                                  \
+  if (!SANITIZER_CAN_FAST_UNWIND)                                      \
+    max_stack = Min(max_stack, 1);                                     \
+  stack.Unwind(pc, bp, nullptr, common_flags()->fast_unwind_on_malloc, \
+               max_stack);
+
+#define GET_STORE_STACK_TRACE \
----------------
thurstond wrote:

Done - now using GET_STACK_TRACE

https://github.com/llvm/llvm-project/pull/133175