[msan] Options for switching between fast and cfi unwinders in run time.

Does not change default behavior.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@177057 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 12 insertions, 3 deletions

diff --git a/lib/msan/msan.cc b/lib/msan/msan.cc
index c1b21430f..a1f8d0fb9 100644
--- a/lib/msan/msan.cc
+++ b/lib/msan/msan.cc
@@ -127,6 +127,8 @@ static void ParseFlagsFromString(Flags *f, const char *str) {
   ParseFlag(str, &f->report_umrs, "report_umrs");
   ParseFlag(str, &f->verbosity, "verbosity");
   ParseFlag(str, &f->strip_path_prefix, "strip_path_prefix");
+  ParseFlag(str, &f->fast_unwind_on_fatal, "fast_unwind_on_fatal");
+  ParseFlag(str, &f->fast_unwind_on_malloc, "fast_unwind_on_malloc");
 }
 
 static void InitializeFlags(Flags *f, const char *options) {
@@ -140,6 +142,8 @@ static void InitializeFlags(Flags *f, const char *options) {
   f->report_umrs = true;
   f->verbosity = 0;
   f->strip_path_prefix = "";
+  f->fast_unwind_on_fatal = false;
+  f->fast_unwind_on_malloc = true;
 
   // Override from user-specified string.
   if (__msan_default_options)
@@ -195,7 +199,7 @@ void PrintWarningWithOrigin(uptr pc, uptr bp, u32 origin) {
   ++msan_report_count;
 
   StackTrace stack;
-  GetStackTrace(&stack, kStackTraceMax, pc, bp, /*fast*/false);
+  GetStackTrace(&stack, kStackTraceMax, pc, bp, flags()->fast_unwind_on_fatal);
 
   u32 report_origin =
     (__msan_track_origins && OriginIsValid(origin)) ? origin : 0;
@@ -294,7 +298,8 @@ void __msan_set_expect_umr(int expect_umr) {
     GET_CALLER_PC_BP_SP;
     (void)sp;
     StackTrace stack;
-    GetStackTrace(&stack, kStackTraceMax, pc, bp, /*fast*/false);
+    GetStackTrace(&stack, kStackTraceMax, pc, bp,
+                  flags()->fast_unwind_on_fatal);
     ReportExpectedUMRNotFound(&stack);
     Die();
   }
diff --git a/lib/msan/msan.h b/lib/msan/msan.h
index 123dd36bf..1880b8ef3 100644
--- a/lib/msan/msan.h
+++ b/lib/msan/msan.h
@@ -79,7 +79,7 @@ void UnpoisonMappedDSO(struct link_map *map);
   if (__msan_get_track_origins() && msan_inited)                   \
     GetStackTrace(&stack, flags()->num_callers,                    \
         StackTrace::GetCurrentPc(), GET_CURRENT_FRAME(),           \
-        /* fast */ true)
+        flags()->fast_unwind_on_malloc)
 
 }  // namespace __msan
 
diff --git a/lib/msan/msan_flags.h b/lib/msan/msan_flags.h
index 0c41c2eb2..cfaf96327 100644
--- a/lib/msan/msan_flags.h
+++ b/lib/msan/msan_flags.h
@@ -26,6 +26,10 @@ struct Flags {
   bool poison_in_malloc;  // default: true
   bool report_umrs;
   const char *strip_path_prefix;
+  // Use fast (frame-pointer-based) unwinder on fatal errors (if available).
+  bool fast_unwind_on_fatal;
+  // Use fast (frame-pointer-based) unwinder on malloc/free (if available).
+  bool fast_unwind_on_malloc;
 };
 
 Flags *flags();