Fix: handle pthread errors

[lttng-ust.git] / liblttng-ust / lttng-ust-comm.c

diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c
index 0765c9b538a6a9370570647fea6780fe49070705..37f21c80d01ea4881e54b74c5b49e998a8588879 100644 (file)
--- a/liblttng-ust/lttng-ust-comm.c
+++ b/liblttng-ust/lttng-ust-comm.c
@@ -236,6 +236,7 @@ int handle_message(struct sock_info *sock_info,
        struct ustcomm_ust_reply lur;
        int shm_fd, wait_fd;
        union ust_args args;
+       ssize_t len;
 
        ust_lock();
 
@@ -346,6 +347,22 @@ end:
                        goto error;
                }
        }
+       /*
+        * LTTNG_UST_TRACEPOINT_FIELD_LIST_GET needs to send the field
+        * after the reply.
+        */
+       if (lur.ret_code == USTCOMM_OK) {
+               switch (lum->cmd) {
+               case LTTNG_UST_TRACEPOINT_FIELD_LIST_GET:
+                       len = ustcomm_send_unix_sock(sock,
+                               &args.field_list.entry,
+                               sizeof(args.field_list.entry));
+                       if (len != sizeof(args.field_list.entry)) {
+                               ret = -1;
+                               goto error;
+                       }
+               }
+       }
        /*
         * We still have the memory map reference, and the fds have been
         * sent to the sessiond. We can therefore close those fds. Note
@@ -832,6 +849,7 @@ int get_timeout(struct timespec *constructor_timeout)
 void __attribute__((constructor)) lttng_ust_init(void)
 {
        struct timespec constructor_timeout;
+       sigset_t sig_all_blocked, orig_parent_mask;
        int timeout_mode;
        int ret;
 
@@ -868,16 +886,39 @@ void __attribute__((constructor)) lttng_ust_init(void)
        if (ret) {
                ERR("Error setting up to local apps");
        }
-       ret = pthread_create(&local_apps.ust_listener, NULL,
-                       ust_listener_thread, &local_apps);
 
+       /* A new thread created by pthread_create inherits the signal mask
+        * from the parent. To avoid any signal being received by the
+        * listener thread, we block all signals temporarily in the parent,
+        * while we create the listener thread.
+        */
+       sigfillset(&sig_all_blocked);
+       ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_parent_mask);
+       if (ret) {
+               ERR("pthread_sigmask: %s", strerror(ret));
+       }
+
+       ret = pthread_create(&global_apps.ust_listener, NULL,
+                       ust_listener_thread, &global_apps);
+       if (ret) {
+               ERR("pthread_create global: %s", strerror(ret));
+       }
        if (local_apps.allowed) {
-               ret = pthread_create(&global_apps.ust_listener, NULL,
-                               ust_listener_thread, &global_apps);
+               ret = pthread_create(&local_apps.ust_listener, NULL,
+                               ust_listener_thread, &local_apps);
+               if (ret) {
+                       ERR("pthread_create local: %s", strerror(ret));
+               }
        } else {
                handle_register_done(&local_apps);
        }
 
+       /* Restore original signal mask in parent */
+       ret = pthread_sigmask(SIG_SETMASK, &orig_parent_mask, NULL);
+       if (ret) {
+               ERR("pthread_sigmask: %s", strerror(ret));
+       }
+
        switch (timeout_mode) {
        case 1: /* timeout wait */
                do {
@@ -951,12 +992,14 @@ void __attribute__((destructor)) lttng_ust_exit(void)
        /* cancel threads */
        ret = pthread_cancel(global_apps.ust_listener);
        if (ret) {
-               ERR("Error cancelling global ust listener thread");
+               ERR("Error cancelling global ust listener thread: %s",
+                       strerror(ret));
        }
        if (local_apps.allowed) {
                ret = pthread_cancel(local_apps.ust_listener);
                if (ret) {
-                       ERR("Error cancelling local ust listener thread");
+                       ERR("Error cancelling local ust listener thread: %s",
+                               strerror(ret));
                }
        }
        /*