On Thu, 12 Oct 2023, Maciej Wieczór-Retman wrote: > On 2023-10-11 at 13:40:48 -0600, Shuah wrote: > >On 10/11/23 02:23, Maciej Wieczor-Retman wrote: > >> Kselftest header defines multiple variadic functions that use printf > >> along with other logic. > >> > >> There is no format checking for the variadic functions that use > >> printing inside kselftest.h. Because of this the compiler won't > >> be able to catch instances of mismatched printf formats and debugging > >> tests might be more difficult. > >> > >> Add the common __printf attribute macro to kselftest.h. > >> > >> Add __printf attribute to every function using formatted printing with > >> variadic arguments. > >> > >> Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@xxxxxxxxx> > >> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> > >> Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx> > >> --- > >> Changelog v4: > >> - Fix typo in patch subject. (Reinette) > >> - Add Reinette's reviewed-by tag. > >> > > > >I still need information on how you found these problems. Please > >add it to change log for each of these patches. > > Sure, I'll add notes on methodology to patches 2-8. I understand that > this patch (1/8) message doesn't need that addition since the problems > it exposes are in separate patches. > > Or would you like me to also note here more specifically what effect it > has in the rest of the series? > > >I am seeing checkpatch warning: > > > >WARNING: Prefer __printf(a, b) over __attribute__((format(printf, a, b))) > >#102: FILE: tools/testing/selftests/kselftest.h:81: > >+#define __printf(a, b) __attribute__((format(printf, a, b))) > > Running checkpatch.pl with --show-types shows the > PREFER_DEFINED_ATTRIBUTE_MACRO is raised. From looking at the error > message in the script it looks like a false positive: > "Prefer $new over __attribute__(($orig_attr$params))\n" > > Please correct me if my train of thought is wrong but I think checkpatch > sees __printf() macro defined and it sees it's raw version > "__attribute__((format(printf, a, b)))" which it wants to replace with > the macro. But since the raw version is found in the define line that is > obviously not possible. Yes, this is clearly a false positive from checkpatch. Checkpatch's logic cannot differentiate the definition from the use of __printf(), it just assumes __printf() is there already, which is not true for selftests. The patch adds the capability to use __printf() elsewhere in the selftests code but of course the definition of __printf() itself has to use __attribute__(). -- i.
