[libFuzzer] disable leak detection if we have tried it for 1000 times w/o finding a leak

llvm-svn: 267770

1 files changed, 9 insertions, 0 deletions

diff --git a/llvm/lib/Fuzzer/FuzzerLoop.cpp b/llvm/lib/Fuzzer/FuzzerLoop.cpp
index cb3a789634e..3b0b339bf9c 100644
--- a/llvm/lib/Fuzzer/FuzzerLoop.cpp
+++ b/llvm/lib/Fuzzer/FuzzerLoop.cpp
@@ -557,6 +557,15 @@ void Fuzzer::TryDetectingAMemoryLeak(uint8_t *Data, size_t Size) {
   RunOneAndUpdateCorpus(Data, Size);
   __lsan_enable();
   if (!HasMoreMallocsThanFrees) return;  // a leak is unlikely.
+  if (NumberOfLeakDetectionAttempts++ > 1000) {
+    Options.DetectLeaks = false;
+    Printf("INFO: libFuzzer disabled leak detection after every mutation.\n"
+           "      Most likely the target function accumulates allocated\n"
+           "      memory in a global state w/o actually leaking it.\n"
+           "      If LeakSanitizer is enabled in this process it will still\n"
+           "      run on the process shutdown.\n");
+    return;
+  }
   // Now perform the actual lsan pass. This is expensive and we must ensure
   // we don't call it too often.
   if (__lsan_do_recoverable_leak_check()) {  // Leak is found, report it.