[Sanitizer] Make slow unwinder on Linux more robust

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@194805 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 10 insertions, 9 deletions

diff --git a/lib/asan/lit_tests/TestCases/double-free.cc b/lib/asan/lit_tests/TestCases/double-free.cc
index e66817e91..6bfd4fa2c 100644
--- a/lib/asan/lit_tests/TestCases/double-free.cc
+++ b/lib/asan/lit_tests/TestCases/double-free.cc
@@ -14,10 +14,12 @@ int main(int argc, char **argv) {
   free(x);
   free(x + argc - 1);  // BOOM
   // CHECK: AddressSanitizer: attempting double-free{{.*}}in thread T0
-  // CHECK: double-free.cc:[[@LINE-2]]
+  // CHECK: #0 0x{{.*}} in {{.*}}free
+  // CHECK: #1 0x{{.*}} in main {{.*}}double-free.cc:[[@LINE-3]]
   // CHECK: freed by thread T0 here:
-  // MALLOC-CTX: double-free.cc:[[@LINE-5]]
+  // MALLOC-CTX: #0 0x{{.*}} in {{.*}}free
+  // MALLOC-CTX: #1 0x{{.*}} in main {{.*}}double-free.cc:[[@LINE-7]]
   // CHECK: allocated by thread T0 here:
-  // MALLOC-CTX: double-free.cc:[[@LINE-10]]
+  // MALLOC-CTX: double-free.cc:[[@LINE-12]]
   return res;
 }
diff --git a/lib/sanitizer_common/sanitizer_linux_libcdep.cc b/lib/sanitizer_common/sanitizer_linux_libcdep.cc
index f6de9f1f8..2940686f1 100644
--- a/lib/sanitizer_common/sanitizer_linux_libcdep.cc
+++ b/lib/sanitizer_common/sanitizer_linux_libcdep.cc
@@ -161,7 +161,7 @@ void StackTrace::SlowUnwindStack(uptr pc, uptr max_depth) {
   UnwindTraceArg arg = {this, Min(max_depth + 1, kStackTraceMax)};
   _Unwind_Backtrace(Unwind_Trace, &arg);
   // We need to pop a few frames so that pc is on top.
-  uptr to_pop = LocatePcInTrace(pc, 6);
+  uptr to_pop = LocatePcInTrace(pc);
   // trace[0] belongs to the current function so we always pop it.
   if (to_pop == 0)
     to_pop = 1;
diff --git a/lib/sanitizer_common/sanitizer_stacktrace.cc b/lib/sanitizer_common/sanitizer_stacktrace.cc
index 62cb12d8d..70ce26bde 100644
--- a/lib/sanitizer_common/sanitizer_stacktrace.cc
+++ b/lib/sanitizer_common/sanitizer_stacktrace.cc
@@ -158,12 +158,11 @@ static bool MatchPc(uptr cur_pc, uptr trace_pc, uptr threshold) {
   return cur_pc - trace_pc <= threshold || trace_pc - cur_pc <= threshold;
 }
 
-uptr
-StackTrace::LocatePcInTrace(uptr pc, uptr max_pc_depth) {
+uptr StackTrace::LocatePcInTrace(uptr pc) {
   // Use threshold to find PC in stack trace, as PC we want to unwind from may
   // slightly differ from return address in the actual unwinded stack trace.
-  const int kPcThreshold = 64;
-  for (uptr i = 0; i < max_pc_depth && i < size; ++i) {
+  const int kPcThreshold = 96;
+  for (uptr i = 0; i < size; ++i) {
     if (MatchPc(pc, trace[i], kPcThreshold))
       return i;
   }
diff --git a/lib/sanitizer_common/sanitizer_stacktrace.h b/lib/sanitizer_common/sanitizer_stacktrace.h
index 73474e65b..5042f2301 100644
--- a/lib/sanitizer_common/sanitizer_stacktrace.h
+++ b/lib/sanitizer_common/sanitizer_stacktrace.h
@@ -69,7 +69,7 @@ struct StackTrace {
                        uptr max_depth);
   void SlowUnwindStack(uptr pc, uptr max_depth);
   void PopStackFrames(uptr count);
-  uptr LocatePcInTrace(uptr pc, uptr max_pc_depth = -1);
+  uptr LocatePcInTrace(uptr pc);
 };
 
 }  // namespace __sanitizer