diff mbox series

net: core: devlink.c: Use built-in RCU list checking

Message ID 20200225122745.31095-1-madhuparnabhowmik10@gmail.com
State Accepted
Delegated to: David Miller
Headers show
Series net: core: devlink.c: Use built-in RCU list checking | expand

Commit Message

Madhuparna Bhowmik Feb. 25, 2020, 12:27 p.m. UTC 
From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

list_for_each_entry_rcu() has built-in RCU and lock checking.

Pass cond argument to list_for_each_entry_rcu() to silence
false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled.

The devlink->lock is held when devlink_dpipe_table_find()
is called in non RCU read side section. Therefore, pass struct devlink
to devlink_dpipe_table_find() for lockdep checking.

Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
---
 net/core/devlink.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

Comments

Jiri Pirko Feb. 25, 2020, 1:06 p.m. UTC | #1 
Tue, Feb 25, 2020 at 01:27:45PM CET, madhuparnabhowmik10@gmail.com wrote:
>From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
>
>list_for_each_entry_rcu() has built-in RCU and lock checking.
>
>Pass cond argument to list_for_each_entry_rcu() to silence
>false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled.
>
>The devlink->lock is held when devlink_dpipe_table_find()
>is called in non RCU read side section. Therefore, pass struct devlink
>to devlink_dpipe_table_find() for lockdep checking.
>
>Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

Reviewed-by: Jiri Pirko <jiri@mellanox.com>
David Miller Feb. 27, 2020, 12:59 a.m. UTC | #2 
From: madhuparnabhowmik10@gmail.com
Date: Tue, 25 Feb 2020 17:57:45 +0530

> From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
> 
> list_for_each_entry_rcu() has built-in RCU and lock checking.
> 
> Pass cond argument to list_for_each_entry_rcu() to silence
> false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled.
> 
> The devlink->lock is held when devlink_dpipe_table_find()
> is called in non RCU read side section. Therefore, pass struct devlink
> to devlink_dpipe_table_find() for lockdep checking.
> 
> Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

Applied, thank you.
diff mbox series

Patch

diff --git a/net/core/devlink.c b/net/core/devlink.c
index e82750bdc496..a92ab58304e5 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -2103,11 +2103,11 @@  static int devlink_dpipe_entry_put(struct sk_buff *skb,
 
 static struct devlink_dpipe_table *
 devlink_dpipe_table_find(struct list_head *dpipe_tables,
-			 const char *table_name)
+			 const char *table_name, struct devlink *devlink)
 {
 	struct devlink_dpipe_table *table;
-
-	list_for_each_entry_rcu(table, dpipe_tables, list) {
+	list_for_each_entry_rcu(table, dpipe_tables, list,
+				lockdep_is_held(&devlink->lock)) {
 		if (!strcmp(table->name, table_name))
 			return table;
 	}
@@ -2226,7 +2226,7 @@  static int devlink_nl_cmd_dpipe_entries_get(struct sk_buff *skb,
 
 	table_name = nla_data(info->attrs[DEVLINK_ATTR_DPIPE_TABLE_NAME]);
 	table = devlink_dpipe_table_find(&devlink->dpipe_table_list,
-					 table_name);
+					 table_name, devlink);
 	if (!table)
 		return -EINVAL;
 
@@ -2382,7 +2382,7 @@  static int devlink_dpipe_table_counters_set(struct devlink *devlink,
 	struct devlink_dpipe_table *table;
 
 	table = devlink_dpipe_table_find(&devlink->dpipe_table_list,
-					 table_name);
+					 table_name, devlink);
 	if (!table)
 		return -EINVAL;
 
@@ -6814,7 +6814,7 @@  bool devlink_dpipe_table_counter_enabled(struct devlink *devlink,
 
 	rcu_read_lock();
 	table = devlink_dpipe_table_find(&devlink->dpipe_table_list,
-					 table_name);
+					 table_name, devlink);
 	enabled = false;
 	if (table)
 		enabled = table->counters_enabled;
@@ -6845,7 +6845,8 @@  int devlink_dpipe_table_register(struct devlink *devlink,
 
 	mutex_lock(&devlink->lock);
 
-	if (devlink_dpipe_table_find(&devlink->dpipe_table_list, table_name)) {
+	if (devlink_dpipe_table_find(&devlink->dpipe_table_list, table_name,
+				     devlink)) {
 		err = -EEXIST;
 		goto unlock;
 	}
@@ -6881,7 +6882,7 @@  void devlink_dpipe_table_unregister(struct devlink *devlink,
 
 	mutex_lock(&devlink->lock);
 	table = devlink_dpipe_table_find(&devlink->dpipe_table_list,
-					 table_name);
+					 table_name, devlink);
 	if (!table)
 		goto unlock;
 	list_del_rcu(&table->list);
@@ -7038,7 +7039,7 @@  int devlink_dpipe_table_resource_set(struct devlink *devlink,
 
 	mutex_lock(&devlink->lock);
 	table = devlink_dpipe_table_find(&devlink->dpipe_table_list,
-					 table_name);
+					 table_name, devlink);
 	if (!table) {
 		err = -EINVAL;
 		goto out;