Fix: Channel creation error return code was not set

[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 96f8eb0b3ead316c0defa96905ff40cfcccb3136..4cae85d6e75719c4c1db5ca26c3627b2bdd2c803 100644 (file)
--- a/src/bin/lttng-sessiond/ust-app.c
+++ b/src/bin/lttng-sessiond/ust-app.c
@@ -1506,8 +1506,16 @@ void ust_app_unregister(int sock)
        /* Assign second node for deletion */
        iter.iter.node = &lta->pid_n.node;
 
+       /*
+        * Ignore return value since the node might have been removed before by an
+        * add replace during app registration because the PID can be reassigned by
+        * the OS.
+        */
        ret = lttng_ht_del(ust_app_ht, &iter);
-       assert(!ret);
+       if (ret) {
+               DBG3("Unregister app by PID %d failed. This can happen on pid reuse",
+                               lta->pid);
+       }
 
        /* Free memory */
        call_rcu(&lta->pid_n.head, delete_ust_app_rcu);
@@ -1975,6 +1983,7 @@ int ust_app_disable_all_event_glb(struct ltt_ust_session *usess,
 int ust_app_create_channel_glb(struct ltt_ust_session *usess,
                struct ltt_ust_channel *uchan)
 {
+       int ret = 0;
        struct lttng_ht_iter iter;
        struct ust_app *app;
        struct ust_app_session *ua_sess;
@@ -2006,9 +2015,11 @@ int ust_app_create_channel_glb(struct ltt_ust_session *usess,
                ua_sess = create_ust_app_session(usess, app);
                if (ua_sess == NULL) {
                        /* The malloc() failed. */
+                       ret = -1;
                        goto error;
                } else if (ua_sess == (void *) -1UL) {
                        /* The application's socket is not valid. Contiuing */
+                       ret = -1;
                        continue;
                }
 
@@ -2016,16 +2027,15 @@ int ust_app_create_channel_glb(struct ltt_ust_session *usess,
                ua_chan = create_ust_app_channel(ua_sess, uchan, app);
                if (ua_chan == NULL) {
                        /* Major problem here and it's maybe the tracer or malloc() */
+                       ret = -1;
                        goto error;
                }
        }
 
        rcu_read_unlock();
 
-       return 0;
-
 error:
-       return -1;
+       return ret;
 }
 
 /*
@@ -2555,7 +2565,8 @@ void ust_app_global_update(struct ltt_ust_session *usess, int sock)
        }
 
        ua_sess = create_ust_app_session(usess, app);
-       if (ua_sess == NULL) {
+       if (ua_sess == NULL || ua_sess == (void *) -1UL) {
+               /* Tracer is gone for this session and has been freed */
                goto error;
        }