X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fust-app.c;h=9dbd49bc3fe5a2911e0516324824383f9257908a;hb=286c991af026bfd127e1de5f97976ff8b291721e;hp=5ebe9917a049bc9ae43ee01fbc6348d2fed2c609;hpb=6a6b20683ccf29e16baceef5d29357001c2c713a;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/ust-app.c b/src/bin/lttng-sessiond/ust-app.c
index 5ebe9917a..9dbd49bc3 100644
--- a/src/bin/lttng-sessiond/ust-app.c
+++ b/src/bin/lttng-sessiond/ust-app.c
@@ -16,6 +16,7 @@
  */
 
 #define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <errno.h>
 #include <inttypes.h>
 #include <pthread.h>
@@ -1446,11 +1447,15 @@ int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
 	}
 
 	/* If event not enabled, disable it on the tracer */
-	if (ua_event->enabled == 0) {
-		ret = disable_ust_event(app, ua_sess, ua_event);
+	if (ua_event->enabled) {
+		/*
+		 * We now need to explicitly enable the event, since it
+		 * is now disabled at creation.
+		 */
+		ret = enable_ust_event(app, ua_sess, ua_event);
 		if (ret < 0) {
 			/*
-			 * If we hit an EPERM, something is wrong with our disable call. If
+			 * If we hit an EPERM, something is wrong with our enable call. If
 			 * we get an EEXIST, there is a problem on the tracer side since we
 			 * just created it.
 			 */
@@ -1727,7 +1732,6 @@ static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
 		if (ret < 0) {
 			goto error;
 		}
-		buffer_reg_pid_add(reg_pid);
 	} else {
 		goto end;
 	}
@@ -1740,9 +1744,18 @@ static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
 			app->byte_order, app->version.major,
 			app->version.minor);
 	if (ret < 0) {
+		/*
+		 * reg_pid->registry->reg.ust is NULL upon error, so we need to
+		 * destroy the buffer registry, because it is always expected
+		 * that if the buffer registry can be found, its ust registry is
+		 * non-NULL.
+		 */
+		buffer_reg_pid_destroy(reg_pid);
 		goto error;
 	}
 
+	buffer_reg_pid_add(reg_pid);
+
 	DBG3("UST app buffer registry per PID created successfully");
 
 end:
@@ -1783,7 +1796,6 @@ static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
 		if (ret < 0) {
 			goto error;
 		}
-		buffer_reg_uid_add(reg_uid);
 	} else {
 		goto end;
 	}
@@ -1796,13 +1808,21 @@ static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
 			app->byte_order, app->version.major,
 			app->version.minor);
 	if (ret < 0) {
+		/*
+		 * reg_uid->registry->reg.ust is NULL upon error, so we need to
+		 * destroy the buffer registry, because it is always expected
+		 * that if the buffer registry can be found, its ust registry is
+		 * non-NULL.
+		 */
+		buffer_reg_uid_destroy(reg_uid, NULL);
 		goto error;
 	}
 	/* Add node to teardown list of the session. */
 	cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
 
-	DBG3("UST app buffer registry per UID created successfully");
+	buffer_reg_uid_add(reg_uid);
 
+	DBG3("UST app buffer registry per UID created successfully");
 end:
 	if (regp) {
 		*regp = reg_uid;
@@ -1964,6 +1984,7 @@ no_match:
 /*
  * Lookup for an ust app context from an lttng_ust_context.
  *
+ * Must be called while holding RCU read side lock.
  * Return an ust_app_ctx object or NULL on error.
  */
 static
@@ -5146,10 +5167,12 @@ unsigned int ust_app_get_nb_stream(struct ltt_ust_session *usess)
 		cds_list_for_each_entry(reg, &usess->buffer_reg_uid_list, lnode) {
 			struct buffer_reg_channel *reg_chan;
 
+			rcu_read_lock();
 			cds_lfht_for_each_entry(reg->registry->channels->ht, &iter.iter,
 					reg_chan, node.node) {
 				ret += reg_chan->stream_count;
 			}
+			rcu_read_unlock();
 		}
 		break;
 	}