X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=libust%2Ftracectl.c;h=b058cb3ce19d0d317790ddbf03103164508d1eb4;hb=e625e9191bcb16522072aa34301cc517392f85ba;hp=bef4537dd4ffeb5311c4e83dabbf60adfbb3fbd3;hpb=fd9c2963da6a81c0d04e09e21156ddcf2fa5efff;p=ust.git

diff --git a/libust/tracectl.c b/libust/tracectl.c
index bef4537..b058cb3 100644
--- a/libust/tracectl.c
+++ b/libust/tracectl.c
@@ -543,6 +543,11 @@ unlock_traces:
 	return retval;
 }
 
+static void release_listener_mutex(void *ptr)
+{
+	pthread_mutex_unlock(&listener_thread_data_mutex);
+}
+
 static void listener_cleanup(void *ptr)
 {
 	pthread_mutex_lock(&listen_sock_mutex);
@@ -1096,6 +1101,7 @@ void *listener_main(void *p)
 
 		for (i = 0; i < nfds; i++) {
 			pthread_mutex_lock(&listener_thread_data_mutex);
+			pthread_cleanup_push(release_listener_mutex, NULL);
 			epoll_sock = (struct ustcomm_sock *)events[i].data.ptr;
 			if (epoll_sock == listen_sock) {
 				addr_size = sizeof(struct sockaddr);
@@ -1124,7 +1130,7 @@ void *listener_main(void *p)
 							   epoll_sock->fd);
 				}
 			}
-			pthread_mutex_unlock(&listener_thread_data_mutex);
+			pthread_cleanup_pop(1);	/* release listener mutex */
 		}
 	}
 
@@ -1711,7 +1717,7 @@ static void ust_after_fork_common(ust_fork_info_t *fork_info)
 
 void ust_after_fork_parent(ust_fork_info_t *fork_info)
 {
-	/* Reenable signals */
+	/* Release mutexes and reenable signals */
 	ust_after_fork_common(fork_info);
 }
 
@@ -1720,7 +1726,15 @@ void ust_after_fork_child(ust_fork_info_t *fork_info)
 	/* First sanitize the child */
 	ust_fork();
 
-	/* Then reenable interrupts */
+	/* Then release mutexes and reenable signals */
 	ust_after_fork_common(fork_info);
+
+	/*
+	 * Make sure we clean up the urcu-bp thread list in the child by running
+	 * the garbage collection before any pthread_create can be called.
+	 * Failure to do so could lead to a deadlock caused by reuse of a thread
+	 * ID before urcu-bp garbage collection is performed.
+	 */
+	synchronize_rcu();
 }