* [PATCH v2] alx: acquire mutex for alx_reinit in alx_change_mtu
@ 2022-03-10 23:27 Niels Dossche
2022-03-12 7:00 ` patchwork-bot+netdevbpf
0 siblings, 1 reply; 2+ messages in thread
From: Niels Dossche @ 2022-03-10 23:27 UTC (permalink / raw)
To: netdev
Cc: Chris Snook, David S. Miller, Jakub Kicinski, Johannes Berg,
Niels Dossche
alx_reinit has a lockdep assertion that the alx->mtx mutex must be held.
alx_reinit is called from two places: alx_reset and alx_change_mtu.
alx_reset does acquire alx->mtx before calling alx_reinit.
alx_change_mtu does not acquire this mutex, nor do its callers or any
path towards alx_change_mtu.
Acquire the mutex in alx_change_mtu.
The issue was introduced when the fine-grained locking was introduced
to the code to replace the RTNL. The same commit also introduced the
lockdep assertion.
Fixes: 4a5fe57e7751 ("alx: use fine-grained locking instead of RTNL")
Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
---
Changes in v2:
- Added Fixes tag and explainer
drivers/net/ethernet/atheros/alx/main.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/atheros/alx/main.c b/drivers/net/ethernet/atheros/alx/main.c
index 4ad3fc72e74e..a89b93cb4e26 100644
--- a/drivers/net/ethernet/atheros/alx/main.c
+++ b/drivers/net/ethernet/atheros/alx/main.c
@@ -1181,8 +1181,11 @@ static int alx_change_mtu(struct net_device *netdev, int mtu)
alx->hw.mtu = mtu;
alx->rxbuf_size = max(max_frame, ALX_DEF_RXBUF_SIZE);
netdev_update_features(netdev);
- if (netif_running(netdev))
+ if (netif_running(netdev)) {
+ mutex_lock(&alx->mtx);
alx_reinit(alx);
+ mutex_unlock(&alx->mtx);
+ }
return 0;
}
--
2.35.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] alx: acquire mutex for alx_reinit in alx_change_mtu
2022-03-10 23:27 [PATCH v2] alx: acquire mutex for alx_reinit in alx_change_mtu Niels Dossche
@ 2022-03-12 7:00 ` patchwork-bot+netdevbpf
0 siblings, 0 replies; 2+ messages in thread
From: patchwork-bot+netdevbpf @ 2022-03-12 7:00 UTC (permalink / raw)
To: Niels Dossche; +Cc: netdev, chris.snook, davem, kuba, johannes
Hello:
This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:
On Fri, 11 Mar 2022 00:27:08 +0100 you wrote:
> alx_reinit has a lockdep assertion that the alx->mtx mutex must be held.
> alx_reinit is called from two places: alx_reset and alx_change_mtu.
> alx_reset does acquire alx->mtx before calling alx_reinit.
> alx_change_mtu does not acquire this mutex, nor do its callers or any
> path towards alx_change_mtu.
> Acquire the mutex in alx_change_mtu.
>
> [...]
Here is the summary with links:
- [v2] alx: acquire mutex for alx_reinit in alx_change_mtu
https://git.kernel.org/netdev/net/c/46b348fd2d81
You are awesome, thank you!
--
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2022-03-10 23:27 [PATCH v2] alx: acquire mutex for alx_reinit in alx_change_mtu Niels Dossche
2022-03-12 7:00 ` patchwork-bot+netdevbpf
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