Re: [PATCH 3/3] xen/console: Fix incorrect format tags for struct tm members

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Fri, 10 Jun 2022, Jan Beulich wrote:
> On 10.06.2022 11:51, Juergen Gross wrote:
> > On 10.06.22 11:44, Jan Beulich wrote:
> >> On 10.06.2022 10:33, Michal Orzel wrote:
> >>> All the members of struct tm are defined as integers but the format tags
> >>> used in console driver for snprintf wrongly expect unsigned values. Fix
> >>> the tags to expect integers.
> >>
> >> Perhaps do things the other way around - convert field types to unsigned
> >> unless negative values can be stored there? This would match our general
> >> aim of using unsigned types when only non-negative values can be held in
> >> variables / parameters / fields.
> > 
> > Don't you think keeping struct tm in sync with the Posix definition should
> > be preferred here?
> 
> Not necessarily, no. It's not just POSIX which has a (imo bad) habit of
> using plain "int" even for values which can never go negative.

I committed the other two patches in the series because already acked
and straightforward.

In this case, I think the straightforward/mechanical fix is the one
Michal suggested in this patch: fixing %u to be %d. We could of course
consider changing the definition of tm, and there are valid reasons to
do that as Jan pointed out, but I think this patch is valid as-in
anyway.

So I am happy to give my reviewed-by for this version of the patch, and
we can still consider changing tm to use unsigned if someone feels like
proposing a patch for that.

Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>

Cheers,

Stefano