Re: [Linux-kernel-mentees] [PATCH] net: core: devlink.c: Hold devlink->lock from the beginning of devlink_dpipe_table_register()
From: Jiri Pirko <jiri@resnulli.us>
Date: 2020-02-23 06:46:47
Also in:
lkml, netdev
Sat, Feb 22, 2020 at 07:52:34AM CET, madhuparnabhowmik10@gmail.com wrote:
quoted hunk ↗ jump to hunk
From: Madhuparna Bhowmik <redacted> 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 <redacted> Signed-off-by: Madhuparna Bhowmik <redacted> --- 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);
Please use "goto unlock" instead of unlocking on multiple places.
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
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