On Thu, Jul 21, 2022 at 02:20:12PM -0700, Justin Stitt wrote:
> When building with Clang we encounter the following warning
> (ARCH=hexagon + CONFIG_FRAME_WARN=0):
> | ../drivers/misc/lkdtm/bugs.c:107:3: error: format specifies type
> | 'unsigned long' but the argument has type 'int' [-Werror,-Wformat]
> | REC_STACK_SIZE, recur_count);
> | ^~~~~~~~~~~~~~
>
> Cast REC_STACK_SIZE to `unsigned long` to match format specifier `%lu`.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/378
> Reported-by: Nathan Chancellor <[email protected]>
> Suggested-by: Nathan Chancellor <[email protected]>
> Signed-off-by: Justin Stitt <[email protected]>
I think this is the right fix, as REC_STACK_SIZE will be 'unsigned long'
when CONFIG_FRAME_WARN is greater than 0 due to the _AC(..., UL) macro,
so the other one should match too. THREAD_SIZE might not be an unsigned
long; I see at least hexagon, microblaze, m68k, powerpc, and sh that
define it as either a regular integer literal with no suffix or
'1 << THREAD_SHIFT', which will both be of type 'int'.
Reviewed-by: Nathan Chancellor <[email protected]>
> ---
> Reported by Nathan here:
> https://lore.kernel.org/all/[email protected]/
>
> drivers/misc/lkdtm/bugs.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
> index 009239ad1d8a..6381255aaecc 100644
> --- a/drivers/misc/lkdtm/bugs.c
> +++ b/drivers/misc/lkdtm/bugs.c
> @@ -29,7 +29,7 @@ struct lkdtm_list {
> #if defined(CONFIG_FRAME_WARN) && (CONFIG_FRAME_WARN > 0)
> #define REC_STACK_SIZE (_AC(CONFIG_FRAME_WARN, UL) / 2)
> #else
> -#define REC_STACK_SIZE (THREAD_SIZE / 8)
> +#define REC_STACK_SIZE ((unsigned long)(THREAD_SIZE / 8))
> #endif
> #define REC_NUM_DEFAULT ((THREAD_SIZE / REC_STACK_SIZE) * 2)
>
> --
> 2.37.1.359.gd136c6c3e2-goog
>