| From 7da11ba5c5066dadc2e96835a6233d56d7b7764a Mon Sep 17 00:00:00 2001 |
| From: Marc Kleine-Budde <mkl@pengutronix.de> |
| Date: Wed, 31 Oct 2018 14:15:13 +0100 |
| Subject: can: dev: __can_get_echo_skb(): print error message, if trying to echo non existing skb |
| |
| From: Marc Kleine-Budde <mkl@pengutronix.de> |
| |
| commit 7da11ba5c5066dadc2e96835a6233d56d7b7764a upstream. |
| |
| Prior to echoing a successfully transmitted CAN frame (by calling |
| can_get_echo_skb()), CAN drivers have to put the CAN frame (by calling |
| can_put_echo_skb() in the transmit function). These put and get function |
| take an index as parameter, which is used to identify the CAN frame. |
| |
| A driver calling can_get_echo_skb() with a index not pointing to a skb |
| is a BUG, so add an appropriate error message. |
| |
| Cc: linux-stable <stable@vger.kernel.org> |
| Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/net/can/dev.c | 27 ++++++++++++++------------- |
| 1 file changed, 14 insertions(+), 13 deletions(-) |
| |
| --- a/drivers/net/can/dev.c |
| +++ b/drivers/net/can/dev.c |
| @@ -426,6 +426,8 @@ EXPORT_SYMBOL_GPL(can_put_echo_skb); |
| struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr) |
| { |
| struct can_priv *priv = netdev_priv(dev); |
| + struct sk_buff *skb = priv->echo_skb[idx]; |
| + struct canfd_frame *cf; |
| |
| if (idx >= priv->echo_skb_max) { |
| netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n", |
| @@ -433,21 +435,20 @@ struct sk_buff *__can_get_echo_skb(struc |
| return NULL; |
| } |
| |
| - if (priv->echo_skb[idx]) { |
| - /* Using "struct canfd_frame::len" for the frame |
| - * length is supported on both CAN and CANFD frames. |
| - */ |
| - struct sk_buff *skb = priv->echo_skb[idx]; |
| - struct canfd_frame *cf = (struct canfd_frame *)skb->data; |
| - u8 len = cf->len; |
| - |
| - *len_ptr = len; |
| - priv->echo_skb[idx] = NULL; |
| - |
| - return skb; |
| + if (!skb) { |
| + netdev_err(dev, "%s: BUG! Trying to echo non existing skb: can_priv::echo_skb[%u]\n", |
| + __func__, idx); |
| + return NULL; |
| } |
| |
| - return NULL; |
| + /* Using "struct canfd_frame::len" for the frame |
| + * length is supported on both CAN and CANFD frames. |
| + */ |
| + cf = (struct canfd_frame *)skb->data; |
| + *len_ptr = cf->len; |
| + priv->echo_skb[idx] = NULL; |
| + |
| + return skb; |
| } |
| |
| /* |