Fix: test all close return values in sessiond

[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.c

diff --git a/src/bin/lttng-sessiond/ust-app.c b/src/bin/lttng-sessiond/ust-app.c
index 2b66b92c07d5e4b41043256c9a2695d0080f6746..6e1dd60fd6b060a1437589a6594b30c0e69deefe 100644 (file)
--- a/src/bin/lttng-sessiond/ust-app.c
+++ b/src/bin/lttng-sessiond/ust-app.c
@@ -198,7 +198,10 @@ void delete_ust_app(struct ust_app *app)
         * closing this socket, otherwise an application could re-use the socket ID
         * and race with the teardown, using the same hash table entry.
         */
-       close(sock);
+       ret = close(sock);
+       if (ret) {
+               PERROR("close");
+       }
 
        DBG2("UST app pid %d deleted", app->key.pid);
        free(app);
@@ -865,6 +868,8 @@ static struct ust_app_session *create_ust_app_session(
                ret = ustctl_create_session(app->key.sock);
                if (ret < 0) {
                        ERR("Creating session for app pid %d", app->key.pid);
+                       /* This means that the tracer is gone... */
+                       ua_sess = (void*) -1UL;
                        goto error;
                }
 
@@ -1266,20 +1271,27 @@ error:
 int ust_app_register(struct ust_register_msg *msg, int sock)
 {
        struct ust_app *lta;
+       int ret;
 
        if ((msg->bits_per_long == 64 && ust_consumerd64_fd == -EINVAL)
                        || (msg->bits_per_long == 32 && ust_consumerd32_fd == -EINVAL)) {
                ERR("Registration failed: application \"%s\" (pid: %d) has "
                        "%d-bit long, but no consumerd for this long size is available.\n",
                        msg->name, msg->pid, msg->bits_per_long);
-               close(sock);
+               ret = close(sock);
+               if (ret) {
+                       PERROR("close");
+               }
                return -EINVAL;
        }
        if (msg->major != LTTNG_UST_COMM_MAJOR) {
                ERR("Registration failed: application \"%s\" (pid: %d) has "
                        "communication protocol version %u.%u, but sessiond supports 2.x.\n",
                        msg->name, msg->pid, msg->major, msg->minor);
-               close(sock);
+               ret = close(sock);
+               if (ret) {
+                       PERROR("close");
+               }
                return -EINVAL;
        }
        lta = zmalloc(sizeof(struct ust_app));
@@ -1757,8 +1769,11 @@ int ust_app_create_channel_glb(struct ltt_ust_session *usess,
                 */
                ua_sess = create_ust_app_session(usess, app);
                if (ua_sess == NULL) {
-                       /* Major problem here and it's maybe the tracer or malloc() */
+                       /* The malloc() failed. */
                        goto error;
+               } else if (ua_sess == (void *) -1UL) {
+                       /* The application's socket is not valid. Contiuing */
+                       continue;
                }
 
                /* Create channel onto application */
@@ -1930,6 +1945,9 @@ int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
                goto skip_setup;
        }
 
+       /* Indicate that the session has been started once */
+       ua_sess->started = 1;
+
        ret = create_ust_app_metadata(ua_sess, usess->pathname, app);
        if (ret < 0) {
                goto error_rcu_unlock;
@@ -1986,7 +2004,6 @@ int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app)
        if (ret < 0) {
                goto error_rcu_unlock;
        }
-       ua_sess->started = 1;
 
 skip_setup:
        /* This start the UST tracing */
@@ -2032,10 +2049,12 @@ int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
                goto error_rcu_unlock;
        }
 
-       /* Not started, continuing. */
-       if (ua_sess->started == 0) {
-               goto end;
-       }
+       /*
+        * If started = 0, it means that stop trace has been called for a session
+        * that was never started. This is a code flow error and should never
+        * happen.
+        */
+       assert(ua_sess->started == 1);
 
        /* This inhibits UST tracing */
        ret = ustctl_stop_session(app->key.sock, ua_sess->handle);
@@ -2066,8 +2085,6 @@ int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app)
                                ret);
        }
 
-       ua_sess->started = 0;
-
 end:
        rcu_read_unlock();
        return 0;