Re: [PATCH v2 net] net: Add error pointer check in bcmsysport.c

[Simon Horman <horms@kernel.org>]

On Mon, Sep 23, 2024 at 05:38:58AM +0000, Dipendra Khadka wrote:
> Add error pointer checks in bcm_sysport_map_queues() and
> bcm_sysport_unmap_queues() before deferencing 'dp'.

nit: dereferencing

     Flagged by checkpatch.pl --codespell

> 
> Signed-off-by: Dipendra Khadka <kdipendra88@gmail.com>

This patch does not compile.
Please take care to make sure your paches compile.

And, moroever, please slow down a bit.  Please take some time to learn the
process by getting one patch accepted. Rather going through that process
with several patches simultaneously.

> ---
> v2: 
>   - Change the subject of the patch to net

I'm sorry to say that the subject is still not correct.

Looking over the git history for this file, I would go for
a prefix of 'net: systemport: '. I would also pass on mentioning
the filename in the subject. Maybe:

	Subject: [PATCH v3 net] net: systemport: correct error pointer handling

Also, I think that it would be better, although more verbose,
to update these functions so that the assignment of dp occurs
just before it is checked.

In the case of bcm_sysport_map_queues(), that would look something like this
(completely untested!):

diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c
index c9faa8540859..7411f69a8806 100644
--- a/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/drivers/net/ethernet/broadcom/bcmsysport.c
@@ -2331,11 +2331,15 @@ static const struct net_device_ops bcm_sysport_netdev_ops = {
 static int bcm_sysport_map_queues(struct net_device *dev,
 				  struct net_device *slave_dev)
 {
-	struct dsa_port *dp = dsa_port_from_netdev(slave_dev);
 	struct bcm_sysport_priv *priv = netdev_priv(dev);
 	struct bcm_sysport_tx_ring *ring;
 	unsigned int num_tx_queues;
 	unsigned int q, qp, port;
+	struct dsa_port *dp;
+
+	dp = dsa_port_from_netdev(slave_dev);
+	if (IS_ERR(dp))
+		return PTR_ERR(dp);

 
 	/* We can't be setting up queue inspection for non directly attached
 	 * switches


This patch is now targeted at 'net'. Which means that you believe
it is a bug fix. I'd say that is reasonable, though it does seem to
be somewhat theoretical. But in any case, a bug fix should
have a Fixes tag, which describes the commit that added the bug.

Alternatively, if it is not a bug fix, then it should be targeted at
net-next (and not have a Fixes tag). Please note that net-next is currently
closed for the v6.12 merge window. It shold re-open after v6.12-rc1 has
been released, which I expect to occur about a week for now. You should
wait for net-next to re-open before posting non-RFC patches for it.

Lastly, when reposting patches, please note the 24h rule.
https://docs.kernel.org/process/maintainer-netdev.html

-- 
pw-bot: changes-requested