mq_notify: block all (application) signals in the worker thread

[musl] / src / aio / aio.c

diff --git a/src/aio/aio.c b/src/aio/aio.c
index a1a3e79..d7e063b 100644 (file)
--- a/src/aio/aio.c
+++ b/src/aio/aio.c
@@ -82,6 +82,8 @@ static size_t io_thread_stack_size;
 
 static struct aio_queue *__aio_get_queue(int fd, int need)
 {
+       sigset_t allmask, origmask;
+       int masked = 0;
        if (fd < 0) {
                errno = EBADF;
                return 0;
@@ -93,6 +95,9 @@ static struct aio_queue *__aio_get_queue(int fd, int need)
        if ((!map || !map[a] || !map[a][b] || !map[a][b][c] || !(q=map[a][b][c][d])) && need) {
                pthread_rwlock_unlock(&maplock);
                if (fcntl(fd, F_GETFD) < 0) return 0;
+               sigfillset(&allmask);
+               masked = 1;
+               pthread_sigmask(SIG_BLOCK, &allmask, &origmask);
                pthread_rwlock_wrlock(&maplock);
                if (!io_thread_stack_size) {
                        unsigned long val = __getauxval(AT_MINSIGSTKSZ);
@@ -119,6 +124,7 @@ static struct aio_queue *__aio_get_queue(int fd, int need)
        if (q) pthread_mutex_lock(&q->lock);
 out:
        pthread_rwlock_unlock(&maplock);
+       if (masked) pthread_sigmask(SIG_SETMASK, &origmask, 0);
        return q;
 }
 
@@ -401,18 +407,26 @@ void __aio_atfork(int who)
        if (who<0) {
                pthread_rwlock_rdlock(&maplock);
                return;
+       } else if (!who) {
+               pthread_rwlock_unlock(&maplock);
+               return;
        }
-       if (who>0 && map) for (int a=0; a<(-1U/2+1)>>24; a++)
+       aio_fd_cnt = 0;
+       if (pthread_rwlock_tryrdlock(&maplock)) {
+               /* Obtaining lock may fail if _Fork was called nor via
+                * fork. In this case, no further aio is possible from
+                * child and we can just null out map so __aio_close
+                * does not attempt to do anything. */
+               map = 0;
+               return;
+       }
+       if (map) for (int a=0; a<(-1U/2+1)>>24; a++)
                if (map[a]) for (int b=0; b<256; b++)
                        if (map[a][b]) for (int c=0; c<256; c++)
                                if (map[a][b][c]) for (int d=0; d<256; d++)
                                        map[a][b][c][d] = 0;
-       pthread_rwlock_unlock(&maplock);
+       /* Re-initialize the rwlock rather than unlocking since there
+        * may have been more than one reference on it in the parent.
+        * We are not a lock holder anyway; the thread in the parent was. */
+       pthread_rwlock_init(&maplock, 0);
 }
-
-weak_alias(aio_cancel, aio_cancel64);
-weak_alias(aio_error, aio_error64);
-weak_alias(aio_fsync, aio_fsync64);
-weak_alias(aio_read, aio_read64);
-weak_alias(aio_write, aio_write64);
-weak_alias(aio_return, aio_return64);