commit fe9268ea9effc367c5772f7f61796dd936f4cbd7
author Matt Morehouse <mascasa@google.com> Fri Apr 26 00:17:41 2019 +0000
committer Copybara-Service <copybara-worker@google.com> Thu Mar 25 23:19:33 2021 -0700
tree bc797aee7fb8e1e212d964a3f31c1741b46249af
parent ca13db5bfca2656190d41cdae3b4ee84f85f9df8

[libFuzzer] Disable MSan interceptors in SIGINT handler.

Summary:
Avoids an MSan false positive if the SIGINT comes while the user
callback is running.  The false positive happens when the interrupt
handler calls opendir() to remove some temporary files, which is
intercepted by MSan.

Fixes https://github.com/google/oss-fuzz/issues/2332.

Reviewers: kcc

Reviewed By: kcc

Subscribers: llvm-commits, Dor1s, metzman

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61163

llvm-svn: 359254
GitOrigin-RevId: 1b76063a5e023b39b4a395d7fc68fd5fe1e6aba3

FuzzerLoop.cpp

diff --git a/FuzzerLoop.cpp b/FuzzerLoop.cpp
index a323a7a..fd5b226 100644
--- a/FuzzerLoop.cpp
+++ b/FuzzerLoop.cpp
@@ -266,6 +266,7 @@
 void Fuzzer::InterruptCallback() {
   Printf("==%lu== libFuzzer: run interrupted; exiting\n", GetPid());
   PrintFinalStats();
+  ScopedDisableMsanInterceptorChecks S; // RmDirRecursive may call opendir().
   RmDirRecursive(TempPath(".dir"));
   // Stop right now, don't perform any at-exit actions.
   _Exit(Options.InterruptExitCode);
@@ -681,7 +682,7 @@
         Size <= CurrentMaxMutationLen)
       NewSize = MD.MutateWithMask(CurrentUnitData, Size, Size,
                                   II.DataFlowTraceForFocusFunction);
-    
+
     // If MutateWithMask either failed or wasn't called, call default Mutate.
     if (!NewSize)
       NewSize = MD.Mutate(CurrentUnitData, Size, CurrentMaxMutationLen);