lkml.org 
[lkml]   [2022]   [Jul]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3] can: slcan: do not sleep with a spin lock held
Date
We can't call close_candev() with a spin lock held, so release the lock
before calling it. After calling close_candev(), we can update the
fields of the private `struct can_priv' without having to acquire the
lock.

Fixes: c4e54b063f42f ("can: slcan: use CAN network device driver API")
Reported-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/linux-kernel/Ysrf1Yc5DaRGN1WE@xsang-OptiPlex-9020/
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>

---

Changes in v3:
- Update the commit message.
- Reset sl->rcount and sl->xleft before releasing the spin lock.

Changes in v2:
- Release the lock just before calling the close_candev().

drivers/net/can/slcan/slcan-core.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/can/slcan/slcan-core.c b/drivers/net/can/slcan/slcan-core.c
index 54d29a410ad5..d40ddc596596 100644
--- a/drivers/net/can/slcan/slcan-core.c
+++ b/drivers/net/can/slcan/slcan-core.c
@@ -689,15 +689,14 @@ static int slc_close(struct net_device *dev)
clear_bit(TTY_DO_WRITE_WAKEUP, &sl->tty->flags);
}
netif_stop_queue(dev);
+ sl->rcount = 0;
+ sl->xleft = 0;
+ spin_unlock_bh(&sl->lock);
close_candev(dev);
sl->can.state = CAN_STATE_STOPPED;
if (sl->can.bittiming.bitrate == CAN_BITRATE_UNKNOWN)
sl->can.bittiming.bitrate = CAN_BITRATE_UNSET;

- sl->rcount = 0;
- sl->xleft = 0;
- spin_unlock_bh(&sl->lock);
-
return 0;
}

--
2.32.0
\
 
 \ /
  Last update: 2022-07-15 09:32    [W:0.067 / U:0.144 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site