musl - musl - an implementation of the standard library for Linux-based systems

diff --git a/src/thread/pthread_mutex_unlock.c b/src/thread/pthread_mutex_unlock.c
index 61a2b947..3733788d 100644
--- a/src/thread/pthread_mutex_unlock.c
+++ b/src/thread/pthread_mutex_unlock.c

@@ -3,7 +3,7 @@

int pthread_mutex_unlock(pthread_mutex_t *m)

{

if (m->_m_type != PTHREAD_MUTEX_NORMAL) {

- if (m->_m_lock != pthread_self()->tid)

+ if (!m->_m_lock || m->_m_lock != __pthread_self()->tid)

return EPERM;

if (m->_m_type == PTHREAD_MUTEX_RECURSIVE && --m->_m_count)

return 0;