[PATCH] net: mvneta: fix locking in mvneta_cpu_online()

[PATCH] net: mvneta: fix locking in mvneta_cpu_online()

[Harshit Mogalapalli]

When port is stopped, unlock before returning

Fixes: 413f0271f396 ("net: protect NAPI enablement with netdev_lock()")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
---
This is based on static analysis, only compile tested
---
 drivers/net/ethernet/marvell/mvneta.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 82f4333fb426..4fe121b9f94b 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -4432,6 +4432,7 @@ static int mvneta_cpu_online(unsigned int cpu, struct hlist_node *node)
 	 */
 	if (pp->is_stopped) {
 		spin_unlock(&pp->lock);
+		netdev_unlock(port->napi.dev);
 		return 0;
 	}
 	netif_tx_stop_all_queues(pp->dev);
-- 
2.39.3

Re: [PATCH] net: mvneta: fix locking in mvneta_cpu_online()

[Harshit Mogalapalli]

Hi,

On 21/01/25 06:20, Harshit Mogalapalli wrote:
> When port is stopped, unlock before returning
> 
Missed adding a period at the end of sentence. Should I send a V2 ?

Thanks,
Harshit
> Fixes: 413f0271f396 ("net: protect NAPI enablement with netdev_lock()")
> Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
> ---
> This is based on static analysis, only compile tested
> ---
>   drivers/net/ethernet/marvell/mvneta.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
> index 82f4333fb426..4fe121b9f94b 100644
> --- a/drivers/net/ethernet/marvell/mvneta.c
> +++ b/drivers/net/ethernet/marvell/mvneta.c
> @@ -4432,6 +4432,7 @@ static int mvneta_cpu_online(unsigned int cpu, struct hlist_node *node)
>   	 */
>   	if (pp->is_stopped) {
>   		spin_unlock(&pp->lock);
> +		netdev_unlock(port->napi.dev);
>   		return 0;
>   	}
>   	netif_tx_stop_all_queues(pp->dev);

Re: [PATCH] net: mvneta: fix locking in mvneta_cpu_online()

[Jakub Kicinski]

On Tue, 21 Jan 2025 06:23:16 +0530 Harshit Mogalapalli wrote:
> On 21/01/25 06:20, Harshit Mogalapalli wrote:
> > When port is stopped, unlock before returning
> >   
> Missed adding a period at the end of sentence. Should I send a V2 ?

It's alright, we can add the period when applying.

Re: [PATCH] net: mvneta: fix locking in mvneta_cpu_online()

[Simon Horman]

On Mon, Jan 20, 2025 at 04:50:02PM -0800, Harshit Mogalapalli wrote:
> When port is stopped, unlock before returning
> 
> Fixes: 413f0271f396 ("net: protect NAPI enablement with netdev_lock()")
> Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
> ---
> This is based on static analysis, only compile tested

Thanks Harshit,

I agree that this is correct.

FWIIW, I would have used the idiomatic approach of a goto to jump to nearly
the end of the function, but the effect is the same either way.

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [PATCH] net: mvneta: fix locking in mvneta_cpu_online()

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Mon, 20 Jan 2025 16:50:02 -0800 you wrote:
> When port is stopped, unlock before returning
> 
> Fixes: 413f0271f396 ("net: protect NAPI enablement with netdev_lock()")
> Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
> ---
> This is based on static analysis, only compile tested
> 
> [...]

Here is the summary with links:
  - net: mvneta: fix locking in mvneta_cpu_online()
    https://git.kernel.org/netdev/net/c/59e00e8ca242

You are awesome, thank you!
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