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* [PATCH] net: core: devlink.c: Hold devlink->lock from the beginning of devlink_dpipe_table_register()
@ 2020-02-23 11:22 madhuparnabhowmik10
  2020-02-23 18:17 ` Jiri Pirko
  0 siblings, 1 reply; 10+ messages in thread
From: madhuparnabhowmik10 @ 2020-02-23 11:22 UTC (permalink / raw)
  To: jiri, davem
  Cc: netdev, linux-kernel, joel, linux-kernel-mentees, paulmck,
	Madhuparna Bhowmik

From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

devlink_dpipe_table_find() should be called under either
rcu_read_lock() or devlink->lock. devlink_dpipe_table_register()
calls devlink_dpipe_table_find() without holding the lock
and acquires it later. Therefore hold the devlink->lock
from the beginning of devlink_dpipe_table_register().

Suggested-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
---
 net/core/devlink.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/net/core/devlink.c b/net/core/devlink.c
index 4c63c9a4c09e..e82750bdc496 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -6838,26 +6838,33 @@ int devlink_dpipe_table_register(struct devlink *devlink,
 				 void *priv, bool counter_control_extern)
 {
 	struct devlink_dpipe_table *table;
-
-	if (devlink_dpipe_table_find(&devlink->dpipe_table_list, table_name))
-		return -EEXIST;
+	int err = 0;
 
 	if (WARN_ON(!table_ops->size_get))
 		return -EINVAL;
 
+	mutex_lock(&devlink->lock);
+
+	if (devlink_dpipe_table_find(&devlink->dpipe_table_list, table_name)) {
+		err = -EEXIST;
+		goto unlock;
+	}
+
 	table = kzalloc(sizeof(*table), GFP_KERNEL);
-	if (!table)
-		return -ENOMEM;
+	if (!table) {
+		err = -ENOMEM;
+		goto unlock;
+	}
 
 	table->name = table_name;
 	table->table_ops = table_ops;
 	table->priv = priv;
 	table->counter_control_extern = counter_control_extern;
 
-	mutex_lock(&devlink->lock);
 	list_add_tail_rcu(&table->list, &devlink->dpipe_table_list);
+unlock:
 	mutex_unlock(&devlink->lock);
-	return 0;
+	return err;
 }
 EXPORT_SYMBOL_GPL(devlink_dpipe_table_register);
 
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 10+ messages in thread
* [PATCH] net: core: devlink.c: Hold devlink->lock from the beginning of devlink_dpipe_table_register()
@ 2020-02-23 10:52 madhuparnabhowmik10
  2020-02-23 11:01 ` Jiri Pirko
  0 siblings, 1 reply; 10+ messages in thread
From: madhuparnabhowmik10 @ 2020-02-23 10:52 UTC (permalink / raw)
  To: jiri, davem
  Cc: netdev, linux-kernel, joel, linux-kernel-mentees, paulmck,
	Madhuparna Bhowmik

From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

devlink_dpipe_table_find() should be called under either
rcu_read_lock() or devlink->lock. devlink_dpipe_table_register()
calls devlink_dpipe_table_find() without holding the lock
and acquires it later. Therefore hold the devlink->lock
from the beginning of devlink_dpipe_table_register().

Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
---
 net/core/devlink.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/net/core/devlink.c b/net/core/devlink.c
index 4c63c9a4c09e..61a350f59741 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -6838,26 +6838,35 @@ int devlink_dpipe_table_register(struct devlink *devlink,
 				 void *priv, bool counter_control_extern)
 {
 	struct devlink_dpipe_table *table;
+	int err = 0;
 
-	if (devlink_dpipe_table_find(&devlink->dpipe_table_list, table_name))
-		return -EEXIST;
+	mutex_lock(&devlink->lock);
 
-	if (WARN_ON(!table_ops->size_get))
-		return -EINVAL;
+	if (devlink_dpipe_table_find(&devlink->dpipe_table_list, table_name)) {
+		err = -EEXIST;
+		goto unlock;
+	}
+
+	if (WARN_ON(!table_ops->size_get)) {
+		err = -EINVAL;
+		goto unlock;
+	}
 
 	table = kzalloc(sizeof(*table), GFP_KERNEL);
-	if (!table)
-		return -ENOMEM;
+	if (!table) {
+		err = -ENOMEM;
+		goto unlock;
+	}
 
 	table->name = table_name;
 	table->table_ops = table_ops;
 	table->priv = priv;
 	table->counter_control_extern = counter_control_extern;
 
-	mutex_lock(&devlink->lock);
 	list_add_tail_rcu(&table->list, &devlink->dpipe_table_list);
+unlock:
 	mutex_unlock(&devlink->lock);
-	return 0;
+	return err;
 }
 EXPORT_SYMBOL_GPL(devlink_dpipe_table_register);
 
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 10+ messages in thread
* [PATCH] net: core: devlink.c: Hold devlink->lock from the beginning of devlink_dpipe_table_register()
@ 2020-02-22  6:52 madhuparnabhowmik10
  2020-02-23  6:43 ` Jiri Pirko
  0 siblings, 1 reply; 10+ messages in thread
From: madhuparnabhowmik10 @ 2020-02-22  6:52 UTC (permalink / raw)
  To: jiri, davem
  Cc: netdev, linux-kernel, joel, frextrite, linux-kernel-mentees,
	paulmck, Madhuparna Bhowmik

From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

devlink_dpipe_table_find() should be called under either
rcu_read_lock() or devlink->lock. devlink_dpipe_table_register()
calls devlink_dpipe_table_find() without holding the lock
and acquires it later. Therefore hold the devlink->lock
from the beginning of devlink_dpipe_table_register().

Suggested-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
---
 net/core/devlink.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/net/core/devlink.c b/net/core/devlink.c
index 3e8c94155d93..ba9dd8cb98c3 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -6840,22 +6840,29 @@ int devlink_dpipe_table_register(struct devlink *devlink,
 {
 	struct devlink_dpipe_table *table;
 
-	if (devlink_dpipe_table_find(&devlink->dpipe_table_list, table_name))
+	mutex_lock(&devlink->lock);
+
+	if (devlink_dpipe_table_find(&devlink->dpipe_table_list, table_name)) {
+		mutex_unlock(&devlink->lock);
 		return -EEXIST;
+	}
 
-	if (WARN_ON(!table_ops->size_get))
+	if (WARN_ON(!table_ops->size_get)) {
+		mutex_unlock(&devlink->lock);
 		return -EINVAL;
+	}
 
 	table = kzalloc(sizeof(*table), GFP_KERNEL);
-	if (!table)
+	if (!table) {
+		mutex_unlock(&devlink->lock);
 		return -ENOMEM;
+	}
 
 	table->name = table_name;
 	table->table_ops = table_ops;
 	table->priv = priv;
 	table->counter_control_extern = counter_control_extern;
 
-	mutex_lock(&devlink->lock);
 	list_add_tail_rcu(&table->list, &devlink->dpipe_table_list);
 	mutex_unlock(&devlink->lock);
 	return 0;
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 10+ messages in thread
* [PATCH] net: core: devlink.c: Hold devlink->lock from the beginning of devlink_dpipe_table_register()
@ 2020-02-21 18:09 madhuparnabhowmik10
  2020-02-22  6:26 ` Jiri Pirko
  0 siblings, 1 reply; 10+ messages in thread
From: madhuparnabhowmik10 @ 2020-02-21 18:09 UTC (permalink / raw)
  To: jiri, davem
  Cc: netdev, linux-kernel, joel, frextrite, linux-kernel-mentees,
	paulmck, Madhuparna Bhowmik

From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

devlink_dpipe_table_find() should be called under either
rcu_read_lock() or devlink->lock. devlink_dpipe_table_register()
calls devlink_dpipe_table_find() without holding the lock
and acquires it later. Therefore hold the devlink->lock
from the beginning of devlink_dpipe_table_register().

Suggested-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
---
 net/core/devlink.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/core/devlink.c b/net/core/devlink.c
index 3e8c94155d93..d54e1f156b6f 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -6840,6 +6840,8 @@ int devlink_dpipe_table_register(struct devlink *devlink,
 {
 	struct devlink_dpipe_table *table;
 
+	mutex_lock(&devlink->lock);
+
 	if (devlink_dpipe_table_find(&devlink->dpipe_table_list, table_name))
 		return -EEXIST;
 
@@ -6855,7 +6857,6 @@ int devlink_dpipe_table_register(struct devlink *devlink,
 	table->priv = priv;
 	table->counter_control_extern = counter_control_extern;
 
-	mutex_lock(&devlink->lock);
 	list_add_tail_rcu(&table->list, &devlink->dpipe_table_list);
 	mutex_unlock(&devlink->lock);
 	return 0;
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 10+ messages in thread
end of thread, other threads:[~2020-02-23 18:17 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
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2020-02-23 11:22 [PATCH] net: core: devlink.c: Hold devlink->lock from the beginning of devlink_dpipe_table_register() madhuparnabhowmik10
2020-02-23 18:17 ` Jiri Pirko
  -- strict thread matches above, loose matches on Subject: below --
2020-02-23 10:52 madhuparnabhowmik10
2020-02-23 11:01 ` Jiri Pirko
2020-02-22  6:52 madhuparnabhowmik10
2020-02-23  6:43 ` Jiri Pirko
2020-02-23 10:56   ` Madhuparna Bhowmik
2020-02-21 18:09 madhuparnabhowmik10
2020-02-22  6:26 ` Jiri Pirko
2020-02-22  6:55   ` Madhuparna Bhowmik

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