netlink: Annotate RCU locking for seq_file walker

tgraf · davem330 · commit 9ce12eb16ffb · 2014-08-14T15:13:40.000-07:00
Silences the following sparse warnings:
net/netlink/af_netlink.c:2926:21: warning: context imbalance in 'netlink_seq_start' - wrong count at exit
net/netlink/af_netlink.c:2972:13: warning: context imbalance in 'netlink_seq_stop' - unexpected unlock

Signed-off-by: Thomas Graf &lt;tgraf@suug.ch&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
@@ -2921,6 +2921,7 @@ static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
 }
 
 static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(RCU)
 {
 	rcu_read_lock();
 	return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN;
@@ -2970,6 +2971,7 @@ static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 }
 
 static void netlink_seq_stop(struct seq_file *seq, void *v)
+	__releases(RCU)
 {
 	rcu_read_unlock();
 }

Original file line number	Diff line number	Diff line change
`@@ -2921,6 +2921,7 @@ static struct sock netlink_seq_socket_idx(struct seq_file seq, loff_t pos)`
`2921`	`2921`	`}`
`2922`	`2922`
`2923`	`2923`	`static void netlink_seq_start(struct seq_file seq, loff_t *pos)`
	`2924`	`+ __acquires(RCU)`
`2924`	`2925`	`{`
`2925`	`2926`	`rcu_read_lock();`
`2926`	`2927`	`return pos ? netlink_seq_socket_idx(seq, pos - 1) : SEQ_START_TOKEN;`
`@@ -2970,6 +2971,7 @@ static void netlink_seq_next(struct seq_file seq, void v, loff_t pos)`
`2970`	`2971`	`}`
`2971`	`2972`
`2972`	`2973`	`static void netlink_seq_stop(struct seq_file seq, void v)`
	`2974`	`+ __releases(RCU)`
`2973`	`2975`	`{`
`2974`	`2976`	`rcu_read_unlock();`
`2975`	`2977`	`}`