X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fthread%2Fpthread_sigmask.c;h=f188782a3277ed6dbcadb1cb8b8af90dc73efbdd;hb=1ec71c531e118971e70ddd0e9e2ed9def2b3c779;hp=88c333f6b682b0c3db71fc35b5e7ed69636272a4;hpb=a63c0104e496f7ba78b64be3cd299b41e8cd427f;p=musl

diff --git a/src/thread/pthread_sigmask.c b/src/thread/pthread_sigmask.c
index 88c333f6..f188782a 100644
--- a/src/thread/pthread_sigmask.c
+++ b/src/thread/pthread_sigmask.c
@@ -5,7 +5,7 @@
 int pthread_sigmask(int how, const sigset_t *restrict set, sigset_t *restrict old)
 {
 	int ret;
-	if ((unsigned)how - SIG_BLOCK > 2U) return EINVAL;
+	if (set && (unsigned)how - SIG_BLOCK > 2U) return EINVAL;
 	ret = -__syscall(SYS_rt_sigprocmask, how, set, old, _NSIG/8);
 	if (!ret && old) {
 		if (sizeof old->__bits[0] == 8) {