2023-03-27 15:29:11

by Wolfram Sang

Subject: [PATCH net-next v2] Revert "sh_eth: remove open coded netif_running()"

This reverts commit ce1fdb065695f49ef6f126d35c1abbfe645d62d5. It turned
out this actually introduces a race condition. netif_running() is not a
suitable check for get_stats.

Reported-by: Sergey Shtylyov <[email protected]>
Signed-off-by: Wolfram Sang <[email protected]>
---

Change since v1:
* added 'net-next' to $subject

drivers/net/ethernet/renesas/sh_eth.c | 6 +++++-
drivers/net/ethernet/renesas/sh_eth.h | 1 +
2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index 2d9787231099..d8ec729825be 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -2441,6 +2441,8 @@ static int sh_eth_open(struct net_device *ndev)

netif_start_queue(ndev);

+ mdp->is_opened = 1;
+
return ret;

out_free_irq:
@@ -2563,7 +2565,7 @@ static struct net_device_stats *sh_eth_get_stats(struct net_device *ndev)
if (mdp->cd->no_tx_cntrs)
return &ndev->stats;

- if (!netif_running(ndev))
+ if (!mdp->is_opened)
return &ndev->stats;

sh_eth_update_stat(ndev, &ndev->stats.tx_dropped, TROCR);
@@ -2612,6 +2614,8 @@ static int sh_eth_close(struct net_device *ndev)
/* Free all the skbuffs in the Rx queue and the DMA buffer. */
sh_eth_ring_free(ndev);

+ mdp->is_opened = 0;
+
pm_runtime_put(&mdp->pdev->dev);

return 0;
diff --git a/drivers/net/ethernet/renesas/sh_eth.h b/drivers/net/ethernet/renesas/sh_eth.h
index f56dbc8a064a..a5c07c6ff44a 100644
--- a/drivers/net/ethernet/renesas/sh_eth.h
+++ b/drivers/net/ethernet/renesas/sh_eth.h
@@ -560,6 +560,7 @@ struct sh_eth_private {

unsigned no_ether_link:1;
unsigned ether_link_active_low:1;
+ unsigned is_opened:1;
unsigned wol_enabled:1;
};

--
2.30.2

2023-03-27 18:12:02

by Sergey Shtylyov

Subject: Re: [PATCH net-next v2] Revert "sh_eth: remove open coded netif_running()"

On 3/27/23 6:21 PM, Wolfram Sang wrote:

> This reverts commit ce1fdb065695f49ef6f126d35c1abbfe645d62d5. It turned
> out this actually introduces a race condition. netif_running() is not a
> suitable check for get_stats.
>
> Reported-by: Sergey Shtylyov <[email protected]>
> Signed-off-by: Wolfram Sang <[email protected]>
[...]

Reviewed-by: Sergey Shtylyov <[email protected]>

MBR, Sergey

2023-03-28 15:07:24

by Simon Horman

Subject: Re: [PATCH net-next v2] Revert "sh_eth: remove open coded netif_running()"

On Mon, Mar 27, 2023 at 05:21:12PM +0200, Wolfram Sang wrote:
> This reverts commit ce1fdb065695f49ef6f126d35c1abbfe645d62d5. It turned
> out this actually introduces a race condition. netif_running() is not a
> suitable check for get_stats.
>
> Reported-by: Sergey Shtylyov <[email protected]>
> Signed-off-by: Wolfram Sang <[email protected]>

Reviewed-by: Simon Horman <[email protected]>

2023-03-29 02:36:02

by patchwork-bot+netdevbpf

Subject: Re: [PATCH net-next v2] Revert "sh_eth: remove open coded netif_running()"

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <[email protected]>:

On Mon, 27 Mar 2023 17:21:12 +0200 you wrote:
> This reverts commit ce1fdb065695f49ef6f126d35c1abbfe645d62d5. It turned
> out this actually introduces a race condition. netif_running() is not a
> suitable check for get_stats.
>
> Reported-by: Sergey Shtylyov <[email protected]>
> Signed-off-by: Wolfram Sang <[email protected]>
>
> [...]

Here is the summary with links:
- [net-next,v2] Revert "sh_eth: remove open coded netif_running()"
https://git.kernel.org/netdev/net-next/c/cdeccd13a03f

You are awesome, thank you!
--
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