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

[Jan Beulich <jbeulich@xxxxxxxx>]

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.

Jan

> --- a/xen/drivers/char/console.c
> +++ b/xen/drivers/char/console.c
> @@ -844,7 +844,7 @@ static void printk_start_of_line(const char *prefix)
>              /* nothing */;
>          else if ( mode == TSM_DATE )
>          {
> -            snprintf(tstr, sizeof(tstr), "[%04u-%02u-%02u %02u:%02u:%02u] ",
> +            snprintf(tstr, sizeof(tstr), "[%04d-%02d-%02d %02d:%02d:%02d] ",
>                       1900 + tm.tm_year, tm.tm_mon + 1, tm.tm_mday,
>                       tm.tm_hour, tm.tm_min, tm.tm_sec);
>              break;
> @@ -852,7 +852,7 @@ static void printk_start_of_line(const char *prefix)
>          else
>          {
>              snprintf(tstr, sizeof(tstr),
> -                     "[%04u-%02u-%02u %02u:%02u:%02u.%03"PRIu64"] ",
> +                     "[%04d-%02d-%02d %02d:%02d:%02d.%03"PRIu64"] ",
>                       1900 + tm.tm_year, tm.tm_mon + 1, tm.tm_mday,
>                       tm.tm_hour, tm.tm_min, tm.tm_sec, nsec / 1000000);
>              break;