[Crash-utility] [PATCH] Fix "log" command when crash is started with "--minimal" option

[David Wysochanski]

On Thu, Aug 6, 2020 at 9:25 AM Dave Wysochanski <dwysocha at redhat.com> wrote:
>
> Commit c86250bce29f introduced the useful '-T' option to print the
> log timestamp in human-readable form.  However, this option does
> not work when crash is invoked with '--minimal' mode, and if tried,
> crash will spin at 100% and continuously crash at a divide by 0
> because machdep->hz == 0.
>
> Fix this by disallowing this option in minimal mode.  In addition,
> only calculate the logic to calculate kt->boot_date.tv_sec
> when this option is enabled.
>
> Fixes: c86250bce29f ("Introduction of the "log -T" option...")
> Signed-off-by: Dave Wysochanski <dwysocha at redhat.com>
> ---
>  kernel.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/kernel.c b/kernel.c
> index 5ed6021..95119f3 100644
> --- a/kernel.c
> +++ b/kernel.c
> @@ -4939,7 +4939,10 @@ cmd_log(void)
>          if (argerrs)
>                  cmd_usage(pc->curcmd, SYNOPSIS);
>
> -       if (kt->boot_date.tv_sec == 0) {
> +       if (msg_flags & SHOW_LOG_CTIME && pc->flags & MINIMAL_MODE)
> +               error(FATAL, "log: option 'T' not available in minimal mode\n");
> +
> +       if (msg_flags & SHOW_LOG_CTIME && kt->boot_date.tv_sec == 0) {
>                 ulonglong uptime_jiffies;
>                 ulong  uptime_sec;
>                 get_uptime(NULL, &uptime_jiffies);
> --
> 2.27.0
>
> --
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Sorry for the spam - please ignore.  I'm going to submit a v3 with
proper acknowledgments.

Thanks