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[80.182.13.224]) by smtp.gmail.com with ESMTPSA id lb11-20020a170907784b00b007246492658asm1692756ejc.117.2022.07.15.00.30.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 15 Jul 2022 00:30:06 -0700 (PDT) From: Dario Binacchi To: linux-kernel@vger.kernel.org Cc: ltp@lists.linux.it, Jeroen Hofstee , lkp@intel.com, Richard Palethorpe , kernel test robot , lkp@lists.01.org, Jiri Slaby , Linux Memory Management List , Dario Binacchi , "David S. Miller" , Eric Dumazet , Greg Kroah-Hartman , Jakub Kicinski , Marc Kleine-Budde , Paolo Abeni , Sebastian Andrzej Siewior , Vincent Mailhol , Wolfgang Grandegger , linux-can@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH v3] can: slcan: do not sleep with a spin lock held Date: Fri, 15 Jul 2022 09:29:51 +0200 Message-Id: <20220715072951.859586-1-dario.binacchi@amarulasolutions.com> X-Mailer: git-send-email 2.32.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org 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 Link: https://lore.kernel.org/linux-kernel/Ysrf1Yc5DaRGN1WE@xsang-OptiPlex-9020/ Signed-off-by: Dario Binacchi --- 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; }