From: David Goulet <dgoulet@efficios.com>
Date: Tue, 22 Jan 2013 16:40:13 +0000 (-0500)
Subject: Fix: add missing rcu read side lock
X-Git-Tag: v2.1.2~24
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=2219ef3594e0823721931a2ce1409b0d93eff663;p=lttng-tools.git

Fix: add missing rcu read side lock

Signed-off-by: David Goulet <dgoulet@efficios.com>
---

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index 491acde45..8c6204c4d 100644
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -152,6 +152,7 @@ static void list_lttng_channels(int domain, struct ltt_session *session,
 		struct lttng_ht_iter iter;
 		struct ltt_ust_channel *uchan;
 
+		rcu_read_lock();
 		cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
 				&iter.iter, uchan, node.node) {
 			strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
@@ -171,6 +172,7 @@ static void list_lttng_channels(int domain, struct ltt_session *session,
 			}
 			i++;
 		}
+		rcu_read_unlock();
 		break;
 	}
 	default:
@@ -433,6 +435,8 @@ static int init_kernel_tracing(struct ltt_kernel_session *session)
 
 	assert(session);
 
+	rcu_read_lock();
+
 	if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
 		cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
 				socket, node.node) {
@@ -450,6 +454,7 @@ static int init_kernel_tracing(struct ltt_kernel_session *session)
 	}
 
 error:
+	rcu_read_unlock();
 	return ret;
 }
 
@@ -643,6 +648,8 @@ static int setup_relayd(struct ltt_session *session)
 
 	DBG2("Setting relayd for session %s", session->name);
 
+	rcu_read_lock();
+
 	if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
 			&& usess->consumer->enabled) {
 		/* For each consumer socket, send relayd sockets */
@@ -679,6 +686,7 @@ static int setup_relayd(struct ltt_session *session)
 	}
 
 error:
+	rcu_read_unlock();
 	return ret;
 }
 
diff --git a/src/bin/lttng-sessiond/context.c b/src/bin/lttng-sessiond/context.c
index 74afd4e0c..cee61f764 100644
--- a/src/bin/lttng-sessiond/context.c
+++ b/src/bin/lttng-sessiond/context.c
@@ -108,16 +108,20 @@ static int add_uctx_to_channel(struct ltt_ust_session *usess, int domain,
 		goto error;
 	}
 
+	rcu_read_lock();
+
 	/* Lookup context before adding it */
 	lttng_ht_lookup(uchan->ctx, (void *)((unsigned long)uctx->ctx.ctx), &iter);
 	uctx_node = lttng_ht_iter_get_node_ulong(&iter);
 	if (uctx_node != NULL) {
 		ret = -EEXIST;
+		rcu_read_unlock();
 		goto error;
 	}
 
 	/* Add ltt UST context node to ltt UST channel */
 	lttng_ht_add_unique_ulong(uchan->ctx, &uctx->node);
+	rcu_read_unlock();
 
 	DBG("Context UST %d added to channel %s", uctx->ctx.ctx, uchan->name);
 
@@ -250,6 +254,7 @@ int context_ust_add(struct ltt_ust_session *usess, int domain,
 		/* Add ctx to channel */
 		ret = add_uctx_to_channel(usess, domain, uchan, ctx);
 	} else {
+		rcu_read_lock();
 		/* Add ctx all events, all channels */
 		cds_lfht_for_each_entry(chan_ht->ht, &iter.iter, uchan, node.node) {
 			ret = add_uctx_to_channel(usess, domain, uchan, ctx);
@@ -258,6 +263,7 @@ int context_ust_add(struct ltt_ust_session *usess, int domain,
 				continue;
 			}
 		}
+		rcu_read_unlock();
 	}
 
 	switch (ret) {
diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index 237a2cf8d..7482f4023 100644
--- 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;
 			}