From 7bd9890f3d74e96f0e1a898f68decfc711de3001 Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Thu, 25 Nov 2021 14:07:37 +0800 Subject: [PATCH 1/3] mctp: serial: cancel tx work on ldisc close We want to ensure that the tx work has finished before returning from the ldisc close op, so do a synchronous cancel. Reported-by: Jiri Slaby Signed-off-by: Jeremy Kerr Signed-off-by: Jakub Kicinski --- drivers/net/mctp/mctp-serial.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/mctp/mctp-serial.c b/drivers/net/mctp/mctp-serial.c index 9ac0e187f36ee..85b407f4df112 100644 --- a/drivers/net/mctp/mctp-serial.c +++ b/drivers/net/mctp/mctp-serial.c @@ -479,6 +479,7 @@ static void mctp_serial_close(struct tty_struct *tty) int idx = dev->idx; unregister_netdev(dev->netdev); + cancel_work_sync(&dev->tx_work); ida_free(&mctp_serial_ida, idx); } From d154cd078ac2d24374e872f3224bf44894867b0a Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Thu, 25 Nov 2021 14:07:38 +0800 Subject: [PATCH 2/3] mctp: serial: enforce fixed MTU The current serial driver requires a maximum MTU of 68, and it doesn't make sense to set a MTU below the MCTP-required baseline (of 68) either. This change sets the min_mtu & max_mtu of the mctp netdev, essentially disallowing changes. By using these instead of a ndo_change_mtu op, we get the netlink extacks reported too. Signed-off-by: Jeremy Kerr Signed-off-by: Jakub Kicinski --- drivers/net/mctp/mctp-serial.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/net/mctp/mctp-serial.c b/drivers/net/mctp/mctp-serial.c index 85b407f4df112..b0e14a63b10d4 100644 --- a/drivers/net/mctp/mctp-serial.c +++ b/drivers/net/mctp/mctp-serial.c @@ -410,7 +410,14 @@ static const struct net_device_ops mctp_serial_netdev_ops = { static void mctp_serial_setup(struct net_device *ndev) { ndev->type = ARPHRD_MCTP; + + /* we limit at the fixed MTU, which is also the MCTP-standard + * baseline MTU, so is also our minimum + */ ndev->mtu = MCTP_SERIAL_MTU; + ndev->max_mtu = MCTP_SERIAL_MTU; + ndev->min_mtu = MCTP_SERIAL_MTU; + ndev->hard_header_len = 0; ndev->addr_len = 0; ndev->tx_queue_len = DEFAULT_TX_QUEUE_LEN; From d1c99f365a1f51f9c7e76ea3c52605cf740b3251 Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Thu, 25 Nov 2021 14:07:39 +0800 Subject: [PATCH 3/3] mctp: serial: remove unnecessary ldisc data check Jiri assures me that a ldisc->open with tty->disc_data set should never happen, so this check doesn't do anything. Reported-by: Jiri Slaby Signed-off-by: Jeremy Kerr Signed-off-by: Jakub Kicinski --- drivers/net/mctp/mctp-serial.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/drivers/net/mctp/mctp-serial.c b/drivers/net/mctp/mctp-serial.c index b0e14a63b10d4..eaa6fb3224bc4 100644 --- a/drivers/net/mctp/mctp-serial.c +++ b/drivers/net/mctp/mctp-serial.c @@ -439,9 +439,6 @@ static int mctp_serial_open(struct tty_struct *tty) if (!tty->ops->write) return -EOPNOTSUPP; - if (tty->disc_data) - return -EEXIST; - idx = ida_alloc(&mctp_serial_ida, GFP_KERNEL); if (idx < 0) return idx;