* [PATCH v2 net] net: dsa: fix error code getting shifted with 4 in dsa_slave_get_sset_count
@ 2021-05-09 19:33 Vladimir Oltean
2021-05-10 0:35 ` Andrew Lunn
2021-05-10 21:40 ` patchwork-bot+netdevbpf
0 siblings, 2 replies; 3+ messages in thread
From: Vladimir Oltean @ 2021-05-09 19:33 UTC (permalink / raw)
To: David S . Miller, Jakub Kicinski, netdev
Cc: Florian Fainelli, Andrew Lunn, Vivien Didelot, Dan Carpenter,
Vladimir Oltean
From: Vladimir Oltean <vladimir.oltean@nxp.com>
DSA implements a bunch of 'standardized' ethtool statistics counters,
namely tx_packets, tx_bytes, rx_packets, rx_bytes. So whatever the
hardware driver returns in .get_sset_count(), we need to add 4 to that.
That is ok, except that .get_sset_count() can return a negative error
code, for example:
b53_get_sset_count
-> phy_ethtool_get_sset_count
-> return -EIO
-EIO is -5, and with 4 added to it, it becomes -1, aka -EPERM. One can
imagine that certain error codes may even become positive, although
based on code inspection I did not see instances of that.
Check the error code first, if it is negative return it as-is.
Based on a similar patch for dsa_master_get_strings from Dan Carpenter:
https://patchwork.kernel.org/project/netdevbpf/patch/YJaSe3RPgn7gKxZv@mwanda/
Fixes: 91da11f870f0 ("net: Distributed Switch Architecture protocol support")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
---
v1 -> v2: preserved variable name of "count" instead of "err".
net/dsa/slave.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 3689ffa2dbb8..988af45dd38f 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -798,13 +798,15 @@ static int dsa_slave_get_sset_count(struct net_device *dev, int sset)
struct dsa_switch *ds = dp->ds;
if (sset == ETH_SS_STATS) {
- int count;
+ int count = 0;
- count = 4;
- if (ds->ops->get_sset_count)
- count += ds->ops->get_sset_count(ds, dp->index, sset);
+ if (ds->ops->get_sset_count) {
+ count = ds->ops->get_sset_count(ds, dp->index, sset);
+ if (count < 0)
+ return count;
+ }
- return count;
+ return count + 4;
} else if (sset == ETH_SS_TEST) {
return net_selftest_get_count();
}
--
2.25.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2 net] net: dsa: fix error code getting shifted with 4 in dsa_slave_get_sset_count
2021-05-09 19:33 [PATCH v2 net] net: dsa: fix error code getting shifted with 4 in dsa_slave_get_sset_count Vladimir Oltean
@ 2021-05-10 0:35 ` Andrew Lunn
2021-05-10 21:40 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: Andrew Lunn @ 2021-05-10 0:35 UTC (permalink / raw)
To: Vladimir Oltean
Cc: David S . Miller, Jakub Kicinski, netdev, Florian Fainelli,
Vivien Didelot, Dan Carpenter, Vladimir Oltean
On Sun, May 09, 2021 at 10:33:38PM +0300, Vladimir Oltean wrote:
> From: Vladimir Oltean <vladimir.oltean@nxp.com>
>
> DSA implements a bunch of 'standardized' ethtool statistics counters,
> namely tx_packets, tx_bytes, rx_packets, rx_bytes. So whatever the
> hardware driver returns in .get_sset_count(), we need to add 4 to that.
>
> That is ok, except that .get_sset_count() can return a negative error
> code, for example:
>
> b53_get_sset_count
> -> phy_ethtool_get_sset_count
> -> return -EIO
>
> -EIO is -5, and with 4 added to it, it becomes -1, aka -EPERM. One can
> imagine that certain error codes may even become positive, although
> based on code inspection I did not see instances of that.
>
> Check the error code first, if it is negative return it as-is.
>
> Based on a similar patch for dsa_master_get_strings from Dan Carpenter:
> https://patchwork.kernel.org/project/netdevbpf/patch/YJaSe3RPgn7gKxZv@mwanda/
>
> Fixes: 91da11f870f0 ("net: Distributed Switch Architecture protocol support")
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Andrew
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2 net] net: dsa: fix error code getting shifted with 4 in dsa_slave_get_sset_count
2021-05-09 19:33 [PATCH v2 net] net: dsa: fix error code getting shifted with 4 in dsa_slave_get_sset_count Vladimir Oltean
2021-05-10 0:35 ` Andrew Lunn
@ 2021-05-10 21:40 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: patchwork-bot+netdevbpf @ 2021-05-10 21:40 UTC (permalink / raw)
To: Vladimir Oltean
Cc: davem, kuba, netdev, f.fainelli, andrew, vivien.didelot,
dan.carpenter, vladimir.oltean
Hello:
This patch was applied to netdev/net.git (refs/heads/master):
On Sun, 9 May 2021 22:33:38 +0300 you wrote:
> From: Vladimir Oltean <vladimir.oltean@nxp.com>
>
> DSA implements a bunch of 'standardized' ethtool statistics counters,
> namely tx_packets, tx_bytes, rx_packets, rx_bytes. So whatever the
> hardware driver returns in .get_sset_count(), we need to add 4 to that.
>
> That is ok, except that .get_sset_count() can return a negative error
> code, for example:
>
> [...]
Here is the summary with links:
- [v2,net] net: dsa: fix error code getting shifted with 4 in dsa_slave_get_sset_count
https://git.kernel.org/netdev/net/c/b94cbc909f1d
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
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^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-05-09 19:33 [PATCH v2 net] net: dsa: fix error code getting shifted with 4 in dsa_slave_get_sset_count Vladimir Oltean
2021-05-10 0:35 ` Andrew Lunn
2021-05-10 21:40 ` patchwork-bot+netdevbpf
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