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[89.177.130.96]) by smtp.gmail.com with ESMTPSA id h5sm7655640wmf.8.2020.02.21.22.26.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 21 Feb 2020 22:26:41 -0800 (PST) Date: Sat, 22 Feb 2020 07:26:40 +0100 From: Jiri Pirko To: madhuparnabhowmik10@gmail.com Cc: jiri@mellanox.com, davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, joel@joelfernandes.org, frextrite@gmail.com, linux-kernel-mentees@lists.linuxfoundation.org, paulmck@kernel.org Subject: Re: [PATCH] net: core: devlink.c: Hold devlink->lock from the beginning of devlink_dpipe_table_register() Message-ID: <20200222062640.GA2228@nanopsycho> References: <20200221180943.17415-1-madhuparnabhowmik10@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200221180943.17415-1-madhuparnabhowmik10@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Fri, Feb 21, 2020 at 07:09:43PM CET, madhuparnabhowmik10@gmail.com wrote: >From: Madhuparna Bhowmik > >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 >Signed-off-by: Madhuparna Bhowmik >--- > 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; You have to handle the error path. > >@@ -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 >