| Message ID | 20211115083756.25971-1-paskripkin@gmail.com (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v3] can: etas_es58x: fix error handling | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Series ignored based on subject |
On Mon. 15 Nov 2021 at 17:37, 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: 8537257874e9 ("can: etas_es58x: add core support for ETAS ES58X CAN USB interfaces") > Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> > --- > > Changes in v3: > - Moved back es58x_dev->netdev[channel_idx] initialization, > since it's unsafe to intialize it _after_ register_candev() > call. Thanks to Johan Hovold <johan@kernel.org> for spotting > it My bad on that. I missed the fact that the netdev_ops becomes active once register_candev() returns. > Changes in v2: > - Fixed Fixes: tag > - Moved es58x_dev->netdev[channel_idx] initialization at the end > of the function > > --- > 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; > return ret; > + } > > netdev_queue_set_dql_min_limit(netdev_get_tx_queue(netdev, 0), > es58x_dev->param->dql_min_limit); > -- > 2.33.1 >
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; return ret; + } netdev_queue_set_dql_min_limit(netdev_get_tx_queue(netdev, 0), es58x_dev->param->dql_min_limit);
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: 8537257874e9 ("can: etas_es58x: add core support for ETAS ES58X CAN USB interfaces") Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> --- Changes in v3: - Moved back es58x_dev->netdev[channel_idx] initialization, since it's unsafe to intialize it _after_ register_candev() call. Thanks to Johan Hovold <johan@kernel.org> for spotting it Changes in v2: - Fixed Fixes: tag - Moved es58x_dev->netdev[channel_idx] initialization at the end of the function --- drivers/net/can/usb/etas_es58x/es58x_core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)