* [PATCH] peak_usb: fix clang build warning
@ 2019-03-07 10:31 Arnd Bergmann
2019-03-07 15:31 ` Nathan Chancellor
2019-03-07 17:40 ` David Miller
0 siblings, 2 replies; 4+ messages in thread
From: Arnd Bergmann @ 2019-03-07 10:31 UTC (permalink / raw)
To: Wolfgang Grandegger, Marc Kleine-Budde, David S. Miller
Cc: Nick Desaulniers, Arnd Bergmann, Gustavo A. R. Silva, linux-can,
netdev, linux-kernel
Clang points out undefined behavior when building the pcan_usb_pro driver:
drivers/net/can/usb/peak_usb/pcan_usb_pro.c:136:15: error: passing an object that undergoes default argument promotion to 'va_start' has undefined behavior [-Werror,-Wvarargs]
Changing the function prototype to avoid argument promotion in the
varargs call avoids the warning, and should make this well-defined.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/net/can/usb/peak_usb/pcan_usb_pro.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_pro.c b/drivers/net/can/usb/peak_usb/pcan_usb_pro.c
index d516def846ab..b388406ac0f5 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb_pro.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_pro.c
@@ -127,7 +127,7 @@ static u8 *pcan_msg_init_empty(struct pcan_usb_pro_msg *pm,
/*
* add one record to a message being built
*/
-static int pcan_msg_add_rec(struct pcan_usb_pro_msg *pm, u8 id, ...)
+static int pcan_msg_add_rec(struct pcan_usb_pro_msg *pm, int id, ...)
{
int len, i;
u8 *pc;
--
2.20.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] peak_usb: fix clang build warning
2019-03-07 10:31 [PATCH] peak_usb: fix clang build warning Arnd Bergmann
@ 2019-03-07 15:31 ` Nathan Chancellor
2019-03-07 15:38 ` Arnd Bergmann
2019-03-07 17:40 ` David Miller
1 sibling, 1 reply; 4+ messages in thread
From: Nathan Chancellor @ 2019-03-07 15:31 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Wolfgang Grandegger, Marc Kleine-Budde, David S. Miller,
Nick Desaulniers, Gustavo A. R. Silva, linux-can, netdev,
linux-kernel
On Thu, Mar 07, 2019 at 11:31:55AM +0100, Arnd Bergmann wrote:
> Clang points out undefined behavior when building the pcan_usb_pro driver:
>
> drivers/net/can/usb/peak_usb/pcan_usb_pro.c:136:15: error: passing an object that undergoes default argument promotion to 'va_start' has undefined behavior [-Werror,-Wvarargs]
>
> Changing the function prototype to avoid argument promotion in the
> varargs call avoids the warning, and should make this well-defined.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://github.com/ClangBuiltLinux/linux/issues/109
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
I wonder if the format specifier in the pr_err statement at the end of
this function should be updated.
> ---
> drivers/net/can/usb/peak_usb/pcan_usb_pro.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_pro.c b/drivers/net/can/usb/peak_usb/pcan_usb_pro.c
> index d516def846ab..b388406ac0f5 100644
> --- a/drivers/net/can/usb/peak_usb/pcan_usb_pro.c
> +++ b/drivers/net/can/usb/peak_usb/pcan_usb_pro.c
> @@ -127,7 +127,7 @@ static u8 *pcan_msg_init_empty(struct pcan_usb_pro_msg *pm,
> /*
> * add one record to a message being built
> */
> -static int pcan_msg_add_rec(struct pcan_usb_pro_msg *pm, u8 id, ...)
> +static int pcan_msg_add_rec(struct pcan_usb_pro_msg *pm, int id, ...)
> {
> int len, i;
> u8 *pc;
> --
> 2.20.0
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] peak_usb: fix clang build warning
2019-03-07 15:31 ` Nathan Chancellor
@ 2019-03-07 15:38 ` Arnd Bergmann
0 siblings, 0 replies; 4+ messages in thread
From: Arnd Bergmann @ 2019-03-07 15:38 UTC (permalink / raw)
To: Nathan Chancellor
Cc: Wolfgang Grandegger, Marc Kleine-Budde, David S. Miller,
Nick Desaulniers, Gustavo A. R. Silva, linux-can, Networking,
Linux Kernel Mailing List
On Thu, Mar 7, 2019 at 4:31 PM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> On Thu, Mar 07, 2019 at 11:31:55AM +0100, Arnd Bergmann wrote:
> > Clang points out undefined behavior when building the pcan_usb_pro driver:
> >
> > drivers/net/can/usb/peak_usb/pcan_usb_pro.c:136:15: error: passing an object that undergoes default argument promotion to 'va_start' has undefined behavior [-Werror,-Wvarargs]
> >
> > Changing the function prototype to avoid argument promotion in the
> > varargs call avoids the warning, and should make this well-defined.
> >
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/109
> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Thanks!
> I wonder if the format specifier in the pr_err statement at the end of
> this function should be updated.
I think it's still ok as it is.
Arnd
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] peak_usb: fix clang build warning
2019-03-07 10:31 [PATCH] peak_usb: fix clang build warning Arnd Bergmann
2019-03-07 15:31 ` Nathan Chancellor
@ 2019-03-07 17:40 ` David Miller
1 sibling, 0 replies; 4+ messages in thread
From: David Miller @ 2019-03-07 17:40 UTC (permalink / raw)
To: arnd; +Cc: wg, mkl, ndesaulniers, gustavo, linux-can, netdev, linux-kernel
From: Arnd Bergmann <arnd@arndb.de>
Date: Thu, 7 Mar 2019 11:31:55 +0100
> Clang points out undefined behavior when building the pcan_usb_pro driver:
>
> drivers/net/can/usb/peak_usb/pcan_usb_pro.c:136:15: error: passing an object that undergoes default argument promotion to 'va_start' has undefined behavior [-Werror,-Wvarargs]
>
> Changing the function prototype to avoid argument promotion in the
> varargs call avoids the warning, and should make this well-defined.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Applied.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2019-03-07 10:31 [PATCH] peak_usb: fix clang build warning Arnd Bergmann
2019-03-07 15:31 ` Nathan Chancellor
2019-03-07 15:38 ` Arnd Bergmann
2019-03-07 17:40 ` David Miller
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