[libFuzzer] set libFuzzer's own SEGV handler even one is already present, but call that handler from ours (unless we are unprotecting lazy counters). Call ProtectLazyCounters later, so that it runs after the initialization code in the target.

llvm-svn: 352713

1 files changed, 4 insertions, 5 deletions

diff --git a/compiler-rt/lib/fuzzer/FuzzerLoop.cpp b/compiler-rt/lib/fuzzer/FuzzerLoop.cpp
index bf600169c4c..fb5aa1f11c1 100644
--- a/compiler-rt/lib/fuzzer/FuzzerLoop.cpp
+++ b/compiler-rt/lib/fuzzer/FuzzerLoop.cpp
@@ -205,11 +205,6 @@ void Fuzzer::StaticCrashSignalCallback() {
   F->CrashCallback();
 }
 
-void Fuzzer::StaticSegvSignalCallback(void *Addr) {
-  if (TPC.UnprotectLazyCounters(Addr)) return;
-  StaticCrashSignalCallback();
-}
-
 void Fuzzer::StaticExitCallback() {
   assert(F);
   F->ExitCallback();
@@ -720,6 +715,10 @@ void Fuzzer::ReadAndExecuteSeedCorpora(const Vector<std::string> &CorpusDirs) {
   uint8_t dummy = 0;
   ExecuteCallback(&dummy, 0);
 
+  // Protect lazy counters here, after the once-init code has been executed.
+  if (Options.LazyCounters)
+    TPC.ProtectLazyCounters();
+
   if (SizedFiles.empty()) {
     Printf("INFO: A corpus is not provided, starting from an empty corpus\n");
     Unit U({'\n'}); // Valid ASCII input.