On Sat. 8 Jan 2022 à 23:33, <trix@xxxxxxxxxx> wrote:
> From: Tom Rix <trix@xxxxxxxxxx>
>
> Clang static analysis reports this problem
> janz-ican3.c:1311:2: warning: Undefined or garbage value returned to caller
> return dlc;
> ^~~~~~~~~~
>
> dlc is only set with this conditional
> if (!(cf->can_id & CAN_RTR_FLAG))
> dlc = cf->len;
>
> But is always returned. So initialize dlc to 0.
Yes. The actual intent is to return a length of 0 for RTR frames.
> Fixes: cc4b08c31b5c ("can: do not increase tx_bytes statistics for RTR frames")
> Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
> ---
> drivers/net/can/janz-ican3.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/can/janz-ican3.c b/drivers/net/can/janz-ican3.c
> index 5b677af5f2a41..808c105cf8f7e 100644
> --- a/drivers/net/can/janz-ican3.c
> +++ b/drivers/net/can/janz-ican3.c
> @@ -1285,7 +1285,7 @@ static unsigned int ican3_get_echo_skb(struct ican3_dev *mod)
> {
> struct sk_buff *skb = skb_dequeue(&mod->echoq);
> struct can_frame *cf;
> - u8 dlc;
> + u8 dlc = 0;
>
> /* this should never trigger unless there is a driver bug */
> if (!skb) {
> --
> 2.26.3
I missed that when writing the patch.
I thought that I did my due diligence by running a "make W=1"
with GCC but I did not catch the error. I should have been more
precocious and run a "make W=2".
Thank you.
Acked-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>
