X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=liblttng-ust-comm%2Flttng-ust-fd-tracker.c;h=1118163a201af456ac6ed28d490e09f458af08ef;hb=283f4bec47781f7a39dde82d02e53add02155f9c;hp=329339f98a038736fe528bc856bdeff1737b4c2b;hpb=f5c453e975e5d417590b9a1be2a9f8504db063c0;p=lttng-ust.git

diff --git a/liblttng-ust-comm/lttng-ust-fd-tracker.c b/liblttng-ust-comm/lttng-ust-fd-tracker.c
index 329339f9..1118163a 100644
--- a/liblttng-ust-comm/lttng-ust-fd-tracker.c
+++ b/liblttng-ust-comm/lttng-ust-fd-tracker.c
@@ -61,8 +61,18 @@
  * Protect the lttng_fd_set. Nests within the ust_lock, and therefore
  * within the libc dl lock. Therefore, we need to fixup the TLS before
  * nesting into this lock.
+ *
+ * The ust_safe_guard_fd_mutex nests within the ust_mutex. This mutex
+ * is also held across fork.
  */
 static pthread_mutex_t ust_safe_guard_fd_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+/*
+ * Cancel state when grabbing the ust_safe_guard_fd_mutex. Saved when
+ * locking, restored on unlock. Protected by ust_safe_guard_fd_mutex.
+ */
+static int ust_safe_guard_saved_cancelstate;
+
 /*
  * Track whether we are within lttng-ust or application, for close
  * system call override by LD_PRELOAD library.
@@ -124,6 +134,12 @@ void lttng_ust_init_fd_tracker(void)
 
 void lttng_ust_lock_fd_tracker(void)
 {
+	int ret, oldstate;
+
+	ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate);
+	if (ret) {
+		ERR("pthread_setcancelstate: %s", strerror(ret));
+	}
 	URCU_TLS(thread_fd_tracking) = 1;
 	/*
 	 * Ensure the compiler don't move the store after the close()
@@ -131,10 +147,14 @@ void lttng_ust_lock_fd_tracker(void)
 	 */
 	cmm_barrier();
 	pthread_mutex_lock(&ust_safe_guard_fd_mutex);
+	ust_safe_guard_saved_cancelstate = oldstate;
 }
 
 void lttng_ust_unlock_fd_tracker(void)
 {
+	int ret, newstate, oldstate;
+
+	newstate = ust_safe_guard_saved_cancelstate;
 	pthread_mutex_unlock(&ust_safe_guard_fd_mutex);
 	/*
 	 * Ensure the compiler don't move the store before the close()
@@ -142,11 +162,15 @@ void lttng_ust_unlock_fd_tracker(void)
 	 */
 	cmm_barrier();
 	URCU_TLS(thread_fd_tracking) = 0;
+	ret = pthread_setcancelstate(newstate, &oldstate);
+	if (ret) {
+		ERR("pthread_setcancelstate: %s", strerror(ret));
+	}
 }
 
 static int dup_std_fd(int fd)
 {
-	int ret;
+	int ret, i;
 	int fd_to_close[STDERR_FILENO + 1];
 	int fd_to_close_count = 0;
 	int dup_cmd = F_DUPFD; /* Default command */
@@ -171,7 +195,7 @@ static int dup_std_fd(int fd)
 	}
 
 	/* Perform dup */
-	for (int i = 0; i < STDERR_FILENO + 1; i++) {
+	for (i = 0; i < STDERR_FILENO + 1; i++) {
 		ret = fcntl(fd, dup_cmd, 0);
 		if (ret < 0) {
 			PERROR("fcntl dup fd");
@@ -192,7 +216,7 @@ static int dup_std_fd(int fd)
 	}
 
 	/* Close intermediary fds */
-	for (int i = 0; i < fd_to_close_count; i++) {
+	for (i = 0; i < fd_to_close_count; i++) {
 		ret = close(fd_to_close[i]);
 		if (ret) {
 			PERROR("close on temporary fd: %d.", fd_to_close[i]);