[Crash-utility] [PATCH] diskdump: Allow zero CPUs for s390

[Dave Anderson]

----- Original Message -----
> Hi Dave,
> 
> For s390 there are cases where makedumpfile generated dumps do not have CPU
> information in the dump header. This happens when old s390 dump tools are
> used to create a dump that do not write the CPU information into the s390
> dump header. We can deal with this situation because we have a fallback that
> gets the CPU register information out of memory (see s390x_get_lowcore).
> 
> So for s390 it would be better that we only get a warning, when crash
> does not find CPU information in a makedumpfile generated dump.
> 
> Signed-off-by: Michael Holzheu <holzheu at linux.vnet.ibm.com>
> ---
>  diskdump.c |    5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> --- a/diskdump.c
> +++ b/diskdump.c
> @@ -369,7 +369,10 @@ restart:
>                  error(INFO, "%s: invalid nr_cpus value: %d\n",
>                          DISKDUMP_VALID() ? "diskdump" : "compressed
>                          kdump",
>                          header->nr_cpus);
> -                        goto err;
> +#if !defined(S390) && !defined(S390X)
> +		/* s390 can get register information also from memory */
> +		goto err;
> +#endif
>          }
>  
>  	/* read sub header */

Queued for crash-5.1.9.

Thanks,
  Dave