fix dup3 ignoring all flags but O_CLOEXEC on archs with SYS_dup2 syscall

[musl] / src / thread / pthread_mutex_unlock.c

diff --git a/src/thread/pthread_mutex_unlock.c b/src/thread/pthread_mutex_unlock.c
index ea9f54d..b66423e 100644 (file)
--- a/src/thread/pthread_mutex_unlock.c
+++ b/src/thread/pthread_mutex_unlock.c
@@ -8,10 +8,11 @@ int __pthread_mutex_unlock(pthread_mutex_t *m)
        int type = m->_m_type & 15;
        int priv = (m->_m_type & 128) ^ 128;
        int new = 0;
+       int old;
 
        if (type != PTHREAD_MUTEX_NORMAL) {
                self = __pthread_self();
-               int old = m->_m_lock;
+               old = m->_m_lock;
                int own = old & 0x3fffffff;
                if (own != self->tid)
                        return EPERM;
@@ -29,7 +30,16 @@ int __pthread_mutex_unlock(pthread_mutex_t *m)
                if (next != &self->robust_list.head) *(volatile void *volatile *)
                        ((char *)next - sizeof(void *)) = prev;
        }
-       cont = a_swap(&m->_m_lock, new);
+       if (type&8) {
+               if (old<0 || a_cas(&m->_m_lock, old, new)!=old) {
+                       if (new) a_store(&m->_m_waiters, -1);
+                       __syscall(SYS_futex, &m->_m_lock, FUTEX_UNLOCK_PI|priv);
+               }
+               cont = 0;
+               waiters = 0;
+       } else {
+               cont = a_swap(&m->_m_lock, new);
+       }
        if (type != PTHREAD_MUTEX_NORMAL && !priv) {
                self->robust_list.pending = 0;
                __vm_unlock();