Fix: add missing rcu read side lock

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

diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index 6f8f1486ca60de5d958352868b9912ddcbdcf24f..7482f402302bde8ab8df531f2de8fbc1ed8e9668 100644 (file)
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -626,7 +626,7 @@ static int update_kernel_stream(struct consumer_data *consumer_data, int fd)
                                        struct lttng_ht_iter iter;
                                        struct consumer_socket *socket;
 
-
+                                       rcu_read_lock();
                                        cds_lfht_for_each_entry(ksess->consumer->socks->ht,
                                                        &iter.iter, socket, node.node) {
                                                /* Code flow error */
@@ -637,9 +637,11 @@ static int update_kernel_stream(struct consumer_data *consumer_data, int fd)
                                                                channel, ksess);
                                                pthread_mutex_unlock(socket->lock);
                                                if (ret < 0) {
+                                                       rcu_read_unlock();
                                                        goto error;
                                                }
                                        }
+                                       rcu_read_unlock();
                                }
                                goto error;
                        }
@@ -691,6 +693,12 @@ static void *thread_manage_kernel(void *data)
 
        DBG("[thread] Thread manage kernel started");
 
+       /*
+        * This first step of the while is to clean this structure which could free
+        * non NULL pointers so zero it before the loop.
+        */
+       memset(&events, 0, sizeof(events));
+
        if (testpoint(thread_manage_kernel)) {
                goto error_testpoint;
        }
@@ -766,7 +774,13 @@ static void *thread_manage_kernel(void *data)
 
                        /* Check for data on kernel pipe */
                        if (pollfd == kernel_poll_pipe[0] && (revents & LPOLLIN)) {
-                               ret = read(kernel_poll_pipe[0], &tmp, 1);
+                               do {
+                                       ret = read(kernel_poll_pipe[0], &tmp, 1);
+                               } while (ret < 0 && errno == EINTR);
+                               /*
+                                * Ret value is useless here, if this pipe gets any actions an
+                                * update is required anyway.
+                                */
                                update_poll_flag = 1;
                                continue;
                        } else {
@@ -1160,7 +1174,9 @@ static void *thread_manage_apps(void *data)
                                        goto error;
                                } else if (revents & LPOLLIN) {
                                        /* Empty pipe */
-                                       ret = read(apps_cmd_pipe[0], &ust_cmd, sizeof(ust_cmd));
+                                       do {
+                                               ret = read(apps_cmd_pipe[0], &ust_cmd, sizeof(ust_cmd));
+                                       } while (ret < 0 && errno == EINTR);
                                        if (ret < 0 || ret < sizeof(ust_cmd)) {
                                                PERROR("read apps cmd pipe");
                                                goto error;
@@ -1312,9 +1328,11 @@ static void *thread_dispatch_ust_registration(void *data)
                         * at some point in time or wait to the end of the world :)
                         */
                        if (apps_cmd_pipe[1] >= 0) {
-                               ret = write(apps_cmd_pipe[1], ust_cmd,
-                                               sizeof(struct ust_command));
-                               if (ret < 0) {
+                               do {
+                                       ret = write(apps_cmd_pipe[1], ust_cmd,
+                                                       sizeof(struct ust_command));
+                               } while (ret < 0 && errno == EINTR);
+                               if (ret < 0 || ret != sizeof(struct ust_command)) {
                                        PERROR("write apps cmd pipe");
                                        if (errno == EBADF) {
                                                /*