Messages in this thread | | | Date | Mon, 15 Nov 2021 10:40:22 +0300 | Subject | Re: [PATCH] can: etas_es58x: fix error handling | From | Pavel Skripkin <> |
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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
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