[libFuzzer] Don't replace custom signal handlers.

Summary:
This allows to keep handlers installed by sanitizers.
In other cases third-party code can replace handlers after libFuzzer
initialization anyway.

Reviewers: kcc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D33522

llvm-svn: 303828
This commit is contained in:
Vitaly Buka 2017-05-25 01:43:13 +00:00
parent a1c532784d
commit bf40f1b6dd
2 changed files with 17 additions and 2 deletions

View File

@ -47,8 +47,21 @@ static void FileSizeExceedHandler(int, siginfo_t *, void *) {
static void SetSigaction(int signum,
void (*callback)(int, siginfo_t *, void *)) {
struct sigaction sigact;
memset(&sigact, 0, sizeof(sigact));
struct sigaction sigact = {};
if (sigaction(signum, nullptr, &sigact)) {
Printf("libFuzzer: sigaction failed with %d\n", errno);
exit(1);
}
if (sigact.sa_flags & SA_SIGINFO) {
if (sigact.sa_sigaction)
return;
} else {
if (sigact.sa_handler != SIG_DFL && sigact.sa_handler != SIG_IGN &&
sigact.sa_handler != SIG_ERR)
return;
}
sigact = {};
sigact.sa_sigaction = callback;
if (sigaction(signum, &sigact, 0)) {
Printf("libFuzzer: sigaction failed with %d\n", errno);

View File

@ -3,3 +3,5 @@ LIBFUZZER_OWN_SEGV_HANDLER: == ERROR: libFuzzer: deadly signal
LIBFUZZER_OWN_SEGV_HANDLER: SUMMARY: libFuzzer: deadly signal
LIBFUZZER_OWN_SEGV_HANDLER: Test unit written to ./crash-
RUN: env ASAN_OPTIONS=handle_segv=1 not LLVMFuzzer-NullDerefTest 2>&1 | FileCheck %s --check-prefix=LIBFUZZER_ASAN_SEGV_HANDLER
LIBFUZZER_ASAN_SEGV_HANDLER: ERROR: AddressSanitizer: {{SEGV|access-violation}} on unknown address