Fix: leak of sessiond configuration on launch of run-as worker

[lttng-tools.git] / src / bin / lttng-consumerd / lttng-consumerd.c

diff --git a/src/bin/lttng-consumerd/lttng-consumerd.c b/src/bin/lttng-consumerd/lttng-consumerd.c
index 1636b9c0d22777798ff220df010c4bc5ca6c9634..ddd07a14279eb3e88bc93b5497e8989a08cb2b3a 100644 (file)
--- a/src/bin/lttng-consumerd/lttng-consumerd.c
+++ b/src/bin/lttng-consumerd/lttng-consumerd.c
@@ -56,6 +56,7 @@
 
 static pthread_t channel_thread, data_thread, metadata_thread,
                sessiond_thread, metadata_timer_thread, health_thread;
+static bool metadata_timer_thread_online;
 
 /* to count the number of times the user pressed ctrl+c */
 static int sigintcount = 0;
@@ -99,14 +100,6 @@ static void sighandler(int sig)
                return;
        }
 
-       /*
-        * Ignore SIGPIPE because it should not stop the consumer whenever a
-        * SIGPIPE is caught through a FD operation.
-        */
-       if (sig == SIGPIPE) {
-               return;
-       }
-
        if (ctx) {
                lttng_consumer_should_exit(ctx);
        }
@@ -127,9 +120,10 @@ static int set_signal_handler(void)
                return ret;
        }
 
-       sa.sa_handler = sighandler;
        sa.sa_mask = sigset;
        sa.sa_flags = 0;
+
+       sa.sa_handler = sighandler;
        if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
                PERROR("sigaction");
                return ret;
@@ -140,6 +134,7 @@ static int set_signal_handler(void)
                return ret;
        }
 
+       sa.sa_handler = SIG_IGN;
        if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
                PERROR("sigaction");
                return ret;
@@ -257,7 +252,7 @@ static int parse_args(int argc, char **argv)
                        lttng_opt_quiet = 1;
                        break;
                case 'v':
-                       lttng_opt_verbose = 1;
+                       lttng_opt_verbose = 3;
                        break;
                case 'V':
                        fprintf(stdout, "%s\n", VERSION);
@@ -314,6 +309,8 @@ int main(int argc, char **argv)
        void *status;
        struct lttng_consumer_local_data *tmp_ctx;
 
+       rcu_register_thread();
+
        if (set_signal_handler()) {
                retval = -1;
                goto exit_set_signal_handler;
@@ -414,7 +411,7 @@ int main(int argc, char **argv)
                set_ulimit();
        }
 
-       if (run_as_create_worker(argv[0]) < 0) {
+       if (run_as_create_worker(argv[0], NULL, NULL) < 0) {
                goto exit_init_data;
        }
 
@@ -510,6 +507,20 @@ int main(int argc, char **argv)
        }
        cmm_smp_mb();   /* Read ready before following operations */
 
+       /*
+        * Create the thread to manage the UST metadata periodic timer and
+        * live timer.
+        */
+       ret = pthread_create(&metadata_timer_thread, NULL,
+                       consumer_timer_thread, (void *) ctx);
+       if (ret) {
+               errno = ret;
+               PERROR("pthread_create");
+               retval = -1;
+               goto exit_metadata_timer_thread;
+       }
+       metadata_timer_thread_online = true;
+
        /* Create thread to manage channels */
        ret = pthread_create(&channel_thread, default_pthread_attr(),
                        consumer_thread_channel_poll,
@@ -542,7 +553,7 @@ int main(int argc, char **argv)
                goto exit_data_thread;
        }
 
-       /* Create the thread to manage the receive of fd */
+       /* Create the thread to manage the reception of fds */
        ret = pthread_create(&sessiond_thread, default_pthread_attr(),
                        consumer_thread_sessiond_poll,
                        (void *) ctx);
@@ -553,34 +564,12 @@ int main(int argc, char **argv)
                goto exit_sessiond_thread;
        }
 
-       /*
-        * Create the thread to manage the UST metadata periodic timer and
-        * live timer.
-        */
-       ret = pthread_create(&metadata_timer_thread, default_pthread_attr(),
-                       consumer_timer_thread, (void *) ctx);
-       if (ret) {
-               errno = ret;
-               PERROR("pthread_create");
-               retval = -1;
-               goto exit_metadata_timer_thread;
-       }
-
-       ret = pthread_detach(metadata_timer_thread);
-       if (ret) {
-               errno = ret;
-               PERROR("pthread_detach");
-               retval = -1;
-               goto exit_metadata_timer_detach;
-       }
 
        /*
         * This is where we start awaiting program completion (e.g. through
         * signal that asks threads to teardown.
         */
 
-exit_metadata_timer_detach:
-exit_metadata_timer_thread:
        ret = pthread_join(sessiond_thread, &status);
        if (ret) {
                errno = ret;
@@ -613,6 +602,8 @@ exit_metadata_thread:
        }
 exit_channel_thread:
 
+exit_metadata_timer_thread:
+
        ret = pthread_join(health_thread, &status);
        if (ret) {
                errno = ret;
@@ -625,11 +616,45 @@ exit_health_thread:
 exit_health_pipe:
 
 exit_init_data:
+       /*
+        * Wait for all pending call_rcu work to complete before tearing
+        * down data structures. call_rcu worker may be trying to
+        * perform lookups in those structures.
+        */
+       rcu_barrier();
+       lttng_consumer_cleanup();
+       /*
+        * Tearing down the metadata timer thread in a
+        * non-fully-symmetric fashion compared to its creation in case
+        * lttng_consumer_cleanup() ends up tearing down timers (which
+        * requires the timer thread to be alive).
+        */
+       if (metadata_timer_thread_online) {
+               /*
+                * Ensure the metadata timer thread exits only after all other
+                * threads are gone, because it is required to perform timer
+                * teardown synchronization.
+                */
+               kill(getpid(), LTTNG_CONSUMER_SIG_EXIT);
+               ret = pthread_join(metadata_timer_thread, &status);
+               if (ret) {
+                       errno = ret;
+                       PERROR("pthread_join metadata_timer_thread");
+                       retval = -1;
+               }
+               ret = consumer_timer_thread_get_channel_monitor_pipe();
+               if (ret >= 0) {
+                       ret = close(ret);
+                       if (ret) {
+                               PERROR("close channel monitor pipe");
+                       }
+               }
+               metadata_timer_thread_online = false;
+       }
        tmp_ctx = ctx;
        ctx = NULL;
        cmm_barrier();  /* Clear ctx for signal handler. */
        lttng_consumer_destroy(tmp_ctx);
-       lttng_consumer_cleanup();
 
        if (health_consumerd) {
                health_app_destroy(health_consumerd);
@@ -643,6 +668,8 @@ exit_health_consumerd_cleanup:
 exit_options:
 exit_set_signal_handler:
 
+       rcu_unregister_thread();
+
        if (!retval) {
                exit(EXIT_SUCCESS);
        } else {