Re: [PATCH v3] can: etas_es58x: fix error handling
flat view
From: Vincent MAILHOL <hidden>
Date: 2021-11-15 09:15:46
Also in:
linux-can, lkml
On Mon. 15 Nov 2021 at 17:37, Pavel Skripkin [off-list ref] 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 <redacted>Acked-by: Vincent Mailhol <redacted>
---
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 [off-list ref] for spotting
itMy bad on that. I missed the fact that the netdev_ops becomes active once register_candev() returns.
quoted hunk ↗ jump to hunk
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