2018-04-06 20:19:02

by Mathieu Malaterre

Subject: [PATCH] backing: silence compiler warning using __printf

__printf marker was added in commit d2cc4dde9206 ("bdi_register: add
__printf verification, fix arg mismatch") for function `bdi_register`
since it is useful to verify format and arguments. Apply equivalent gcc
attribute to `bdi_register_va`.

Remove warning triggered with W=1:

mm/backing-dev.c:881:2: warning: function might be possible candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]

Signed-off-by: Mathieu Malaterre <[email protected]>
---
include/linux/backing-dev.h | 1 +
1 file changed, 1 insertion(+)

diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 3e4ce54d84ab..0e9c0f71f726 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -28,6 +28,7 @@ void bdi_put(struct backing_dev_info *bdi);

__printf(2, 3)
int bdi_register(struct backing_dev_info *bdi, const char *fmt, ...);
+__printf(2, 0)
int bdi_register_va(struct backing_dev_info *bdi, const char *fmt,
va_list args);
int bdi_register_owner(struct backing_dev_info *bdi, struct device *owner);
--
2.11.0

2018-04-09 15:54:35

by Jan Kara

Subject: Re: [PATCH] backing: silence compiler warning using __printf

On Fri 06-04-18 22:14:51, Mathieu Malaterre wrote:
> __printf marker was added in commit d2cc4dde9206 ("bdi_register: add
> __printf verification, fix arg mismatch") for function `bdi_register`
> since it is useful to verify format and arguments. Apply equivalent gcc
> attribute to `bdi_register_va`.
>
> Remove warning triggered with W=1:
>
> mm/backing-dev.c:881:2: warning: function might be possible candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]
>
> Signed-off-by: Mathieu Malaterre <[email protected]>
> ---
> include/linux/backing-dev.h | 1 +
> 1 file changed, 1 insertion(+)

Yeah, the patch looks good. You can add:

Reviewed-by: Jan Kara <[email protected]>

Honza

>
> diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
> index 3e4ce54d84ab..0e9c0f71f726 100644
> --- a/include/linux/backing-dev.h
> +++ b/include/linux/backing-dev.h
> @@ -28,6 +28,7 @@ void bdi_put(struct backing_dev_info *bdi);
>
> __printf(2, 3)
> int bdi_register(struct backing_dev_info *bdi, const char *fmt, ...);
> +__printf(2, 0)
> int bdi_register_va(struct backing_dev_info *bdi, const char *fmt,
> va_list args);
> int bdi_register_owner(struct backing_dev_info *bdi, struct device *owner);
> --
> 2.11.0
>
--
Jan Kara <[email protected]>
SUSE Labs, CR

2018-04-09 15:56:02

by Jens Axboe

Subject: Re: [PATCH] backing: silence compiler warning using __printf

On 4/6/18 2:14 PM, Mathieu Malaterre wrote:
> __printf marker was added in commit d2cc4dde9206 ("bdi_register: add
> __printf verification, fix arg mismatch") for function `bdi_register`
> since it is useful to verify format and arguments. Apply equivalent gcc
> attribute to `bdi_register_va`.
>
> Remove warning triggered with W=1:
>
> mm/backing-dev.c:881:2: warning: function might be possible candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]

Applied, thanks.

--
Jens Axboe