From: Pavel Skripkin <paskripkin@gmail.com>
To: Vincent MAILHOL <mailhol.vincent@wanadoo.fr>
Cc: wg@grandegger.com, mkl@pengutronix.de, davem@davemloft.net,
kuba@kernel.org, linux-can@vger.kernel.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] can: etas_es58x: fix error handling
Date: Mon, 15 Nov 2021 10:40:22 +0300 [thread overview]
Message-ID: <9a811cfb-1e9c-763f-0c8f-577f21d8f3cc@gmail.com> (raw)
In-Reply-To: <CAMZ6Rq+orfUuUCCgeWyGc7P0vp3t-yjf_g9H=Jhk43f1zXGfDQ@mail.gmail.com>
On 11/15/21 08:27, Vincent MAILHOL wrote:
> Hi Pavel,
>
> Thanks for the patch!
>
> On Mon. 15 Nov 2021 at 05:58, Pavel Skripkin <paskripkin@gmail.com> wrote:
>> When register_candev() fails there are 2 possible device states:
>> NETREG_UNINITIALIZED and NETREG_UNREGISTERED. None of them are suitable
>> for calling unregister_candev(), because of following checks in
>> unregister_netdevice_many():
>>
>> if (dev->reg_state == NETREG_UNINITIALIZED)
>> WARN_ON(1);
>> ...
>> BUG_ON(dev->reg_state != NETREG_REGISTERED);
>>
>> To avoid possible BUG_ON or WARN_ON let's free current netdev before
>> returning from es58x_init_netdev() and leave others (registered)
>> net devices for es58x_free_netdevs().
>>
>> Fixes: 004653f0abf2 ("can: etas_es58x: add es58x_free_netdevs() to factorize code")
>
Hi, Vincent!
> Fixes: 8537257874e9 ("can: etas_es58x: add core support for ETAS ES58X
> CAN USB interfaces")
>
> The bug existed from the initial commit. Prior to the
> introduction of es58x_free_netdevs(), unregister_candev() was
> called in the error handling of es58x_probe():
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/can/usb/etas_es58x/es58x_core.c?id=8537257874e949a59c834cecfd5a063e11b64b0b#n2234
>
I see, will fix in v2
>> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
>> ---
>> drivers/net/can/usb/etas_es58x/es58x_core.c | 5 ++++-
>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/can/usb/etas_es58x/es58x_core.c b/drivers/net/can/usb/etas_es58x/es58x_core.c
>> index 96a13c770e4a..41c721f2fbbe 100644
>> --- a/drivers/net/can/usb/etas_es58x/es58x_core.c
>> +++ b/drivers/net/can/usb/etas_es58x/es58x_core.c
>> @@ -2098,8 +2098,11 @@ static int es58x_init_netdev(struct es58x_device *es58x_dev, int channel_idx)
>> netdev->flags |= IFF_ECHO; /* We support local echo */
>>
>> ret = register_candev(netdev);
>> - if (ret)
>> + if (ret) {
>> + free_candev(netdev);
>> + es58x_dev->netdev[channel_idx] = NULL;
>
> A nitpick, but if you don’t mind, I would prefer to set
> es58x_dev->netdev[channel_idx] after register_candev() succeeds
> so that we do not have to reset it to NULL in the error handling.
>
> diff --git a/drivers/net/can/usb/etas_es58x/es58x_core.c
> b/drivers/net/can/usb/etas_es58x/es58x_core.c
> index ce2b9e1ce3af..fb0daad9b9c8 100644
> --- a/drivers/net/can/usb/etas_es58x/es58x_core.c
> +++ b/drivers/net/can/usb/etas_es58x/es58x_core.c
> @@ -2091,18 +2091,20 @@ static int es58x_init_netdev(struct
> es58x_device *es58x_dev, int channel_idx)
> return -ENOMEM;
> }
> SET_NETDEV_DEV(netdev, dev);
> - es58x_dev->netdev[channel_idx] = netdev;
> es58x_init_priv(es58x_dev, es58x_priv(netdev), channel_idx);
>
> netdev->netdev_ops = &es58x_netdev_ops;
> netdev->flags |= IFF_ECHO; /* We support local echo */
>
> ret = register_candev(netdev);
> - if (ret)
> + if (ret) {
> + free_candev(netdev);
> return ret;
> + }
>
> netdev_queue_set_dql_min_limit(netdev_get_tx_queue(netdev, 0),
> es58x_dev->param->dql_min_limit);
> + es58x_dev->netdev[channel_idx] = netdev;
>
> return ret;
> }
>
Also will do in v2. Thank you for your review :)
With regards,
Pavel Skripkin
next prev parent reply other threads:[~2021-11-15 7:40 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-14 20:58 [PATCH] can: etas_es58x: fix error handling Pavel Skripkin
2021-11-15 5:27 ` Vincent MAILHOL
2021-11-15 7:40 ` Pavel Skripkin [this message]
2021-11-15 7:51 ` [PATCH v2] " Pavel Skripkin
2021-11-15 8:11 ` Johan Hovold
2021-11-15 8:15 ` Pavel Skripkin
2021-11-15 8:16 ` Johan Hovold
2021-11-15 8:30 ` Pavel Skripkin
2021-11-15 9:24 ` Vincent MAILHOL
2021-11-15 9:26 ` Pavel Skripkin
2021-11-15 8:37 ` [PATCH v3] " Pavel Skripkin
2021-11-15 9:15 ` Vincent MAILHOL
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