[libFuzzer] Dump trace and provide correct msg for overwritten input.

Summary:
Now crashes with a stacktrace and uses 'overwrites-const-input' as the error
message instead of 'out-of-memory'.

Reviewers: morehouse, Dor1s

Reviewed By: morehouse, Dor1s

Subscribers: #sanitizers, llvm-commits, metzman, Dor1s

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D68067

llvm-svn: 373130

diff --git a/compiler-rt/lib/fuzzer/FuzzerLoop.cpp b/compiler-rt/lib/fuzzer/FuzzerLoop.cpp
index 7150a11..96ab544 100644 (file)
--- a/compiler-rt/lib/fuzzer/FuzzerLoop.cpp
+++ b/compiler-rt/lib/fuzzer/FuzzerLoop.cpp
@@ -515,8 +515,10 @@ size_t Fuzzer::GetCurrentUnitInFuzzingThead(const uint8_t **Data) const {
 void Fuzzer::CrashOnOverwrittenData() {
   Printf("==%d== ERROR: libFuzzer: fuzz target overwrites its const input\n",
          GetPid());
+  PrintStackTrace();
+  Printf("SUMMARY: libFuzzer: overwrites-const-input\n");
   DumpCurrentUnit("crash-");
-  Printf("SUMMARY: libFuzzer: out-of-memory\n");
+  PrintFinalStats();
   _Exit(Options.ErrorExitCode); // Stop right now.
 }