Re: [PATCH] rt-tests: cyclictest: Remove warnings due different signedness in comparison

[John Kacur <jkacur@redhat.com>]

On Wed, 9 Aug 2023, Eder Zulian wrote:

> Type casting used to remove compiler warnings due to comparison of integer expressions of different signedness.
> 
> Signed-off-by: Eder Zulian <ezulian@redhat.com>
> ---
>  src/cyclictest/cyclictest.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
> index 7b0f80f..3b47d53 100644
> --- a/src/cyclictest/cyclictest.c
> +++ b/src/cyclictest/cyclictest.c
> @@ -317,8 +317,8 @@ static int raise_soft_prio(int policy, const struct sched_param *param)
>  		return err;
>  	}
>  
> -	soft_max = (rlim.rlim_cur == RLIM_INFINITY) ? policy_max : rlim.rlim_cur;
> -	hard_max = (rlim.rlim_max == RLIM_INFINITY) ? policy_max : rlim.rlim_max;
> +	soft_max = (rlim.rlim_cur == RLIM_INFINITY) ? (unsigned)policy_max : rlim.rlim_cur;
> +	hard_max = (rlim.rlim_max == RLIM_INFINITY) ? (unsigned)policy_max : rlim.rlim_max;
>  
>  	if (prio > soft_max && prio <= hard_max) {
>  		rlim.rlim_cur = prio;
> -- 
> 2.39.3
> 
> 
Although we are not as strict as the kernel, we try to follow most of 
their coding rules, and I usually run checkkpatch on patches.

../linux/scripts/checkpatch.pl eder2.patch 
WARNING: Possible unwrapped commit description (prefer a maximum 75 chars 
per line)
#8: 
Type casting used to remove compiler warnings due to comparison of integer 
expressions of different signedness.

WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
#25: FILE: src/cyclictest/cyclictest.c:320:
+	soft_max = (rlim.rlim_cur == RLIM_INFINITY) ? (unsigned)policy_max 
: rlim.rlim_cur;

WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
#26: FILE: src/cyclictest/cyclictest.c:321:
+	hard_max = (rlim.rlim_max == RLIM_INFINITY) ? (unsigned)policy_max 
: rlim.rlim_max;

total: 0 errors, 3 warnings, 10 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or 
--fix-inplace.

eder2.patch has style problems, please review.

NOTE: If any of the errors are false positives, please report
      them to the maintainer, see CHECKPATCH in MAINTAINERS.

-------
The cast is fine in this case, we can't just use an unsigned int
because sched_get_priority_max could return an error. So, just fix
the unwrapped line in your commit message and make the cast
unsigned int

and then I'll apply it.

Thanks

John