[3.19.y-ckt stable] Patch "can: fix loss of CAN frames in raw_rcv" has been added to staging queue

[Oliver Hartkopp]

Hello Kamal,

this patch is only relevant for v4.1.x where the problematic commit
514ac99c64b "can: fix multiple delivery of a single CAN frame for overlapping
CAN filters" has been introduced.

So we can omit this patch below for 3.19.y-ckt stable as it does not fix 
anything there.

We just missed to add a marker '# v4.1' in that fix.

Sorry for the noise.

Best regards,
Oliver


On 16.07.2015 03:01, Kamal Mostafa wrote:
> This is a note to let you know that I have just added a patch titled
>
>      can: fix loss of CAN frames in raw_rcv
>
> to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree
> which can be found at:
>
>      http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue
>
> This patch is scheduled to be released in version 3.19.y-ckt4.
>
> If you, or anyone else, feels it should not be added to this tree, please
> reply to this email.
>
> For more information about the 3.19.y-ckt tree, see
> https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
>
> Thanks.
> -Kamal
>
> ------
>
>  From 42fd9bd1b9ba6558f060f9077070f71a9f31de90 Mon Sep 17 00:00:00 2001
> From: Oliver Hartkopp <socketcan at hartkopp.net>
> Date: Sun, 21 Jun 2015 18:50:44 +0200
> Subject: can: fix loss of CAN frames in raw_rcv
>
> commit 36c01245eb8046c16eee6431e7dbfbb302635fa8 upstream.
>
> As reported by Manfred Schlaegl here
>
>     http://marc.info/?l=linux-netdev&m=143482089824232&w=2
>
> commit 514ac99c64b "can: fix multiple delivery of a single CAN frame for
> overlapping CAN filters" requires the skb->tstamp to be set to check for
> identical CAN skbs.
>
> As net timestamping is influenced by several players (netstamp_needed and
> netdev_tstamp_prequeue) Manfred missed a proper timestamp which leads to
> CAN frame loss.
>
> As skb timestamping became now mandatory for CAN related skbs this patch
> makes sure that received CAN skbs always have a proper timestamp set.
> Maybe there's a better solution in the future but this patch fixes the
> CAN frame loss so far.
>
> Reported-by: Manfred Schlaegl <manfred.schlaegl at gmx.at>
> Signed-off-by: Oliver Hartkopp <socketcan at hartkopp.net>
> Signed-off-by: Marc Kleine-Budde <mkl at pengutronix.de>
> Signed-off-by: Kamal Mostafa <kamal at canonical.com>
> ---
>   drivers/net/can/dev.c   | 5 +++++
>   drivers/net/can/slcan.c | 1 +
>   drivers/net/can/vcan.c  | 3 +++
>   net/can/af_can.c        | 6 +++++-
>   4 files changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
> index 62ca0e8..44fc75f 100644
> --- a/drivers/net/can/dev.c
> +++ b/drivers/net/can/dev.c
> @@ -438,6 +438,9 @@ unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
>   		struct can_frame *cf = (struct can_frame *)skb->data;
>   		u8 dlc = cf->can_dlc;
>
> +		if (!(skb->tstamp.tv64))
> +			__net_timestamp(skb);
> +
>   		netif_rx(priv->echo_skb[idx]);
>   		priv->echo_skb[idx] = NULL;
>
> @@ -574,6 +577,7 @@ struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
>   	if (unlikely(!skb))
>   		return NULL;
>
> +	__net_timestamp(skb);
>   	skb->protocol = htons(ETH_P_CAN);
>   	skb->pkt_type = PACKET_BROADCAST;
>   	skb->ip_summed = CHECKSUM_UNNECESSARY;
> @@ -602,6 +606,7 @@ struct sk_buff *alloc_canfd_skb(struct net_device *dev,
>   	if (unlikely(!skb))
>   		return NULL;
>
> +	__net_timestamp(skb);
>   	skb->protocol = htons(ETH_P_CANFD);
>   	skb->pkt_type = PACKET_BROADCAST;
>   	skb->ip_summed = CHECKSUM_UNNECESSARY;
> diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c
> index c837eb9..f64f529 100644
> --- a/drivers/net/can/slcan.c
> +++ b/drivers/net/can/slcan.c
> @@ -207,6 +207,7 @@ static void slc_bump(struct slcan *sl)
>   	if (!skb)
>   		return;
>
> +	__net_timestamp(skb);
>   	skb->dev = sl->dev;
>   	skb->protocol = htons(ETH_P_CAN);
>   	skb->pkt_type = PACKET_BROADCAST;
> diff --git a/drivers/net/can/vcan.c b/drivers/net/can/vcan.c
> index 674f367..0ce868d 100644
> --- a/drivers/net/can/vcan.c
> +++ b/drivers/net/can/vcan.c
> @@ -78,6 +78,9 @@ static void vcan_rx(struct sk_buff *skb, struct net_device *dev)
>   	skb->dev       = dev;
>   	skb->ip_summed = CHECKSUM_UNNECESSARY;
>
> +	if (!(skb->tstamp.tv64))
> +		__net_timestamp(skb);
> +
>   	netif_rx_ni(skb);
>   }
>
> diff --git a/net/can/af_can.c b/net/can/af_can.c
> index 32d710e..689c818 100644
> --- a/net/can/af_can.c
> +++ b/net/can/af_can.c
> @@ -310,8 +310,12 @@ int can_send(struct sk_buff *skb, int loop)
>   		return err;
>   	}
>
> -	if (newskb)
> +	if (newskb) {
> +		if (!(newskb->tstamp.tv64))
> +			__net_timestamp(newskb);
> +
>   		netif_rx_ni(newskb);
> +	}
>
>   	/* update statistics */
>   	can_stats.tx_frames++;
> --
> 1.9.1
>