From mboxrd@z Thu Jan  1 00:00:00 1970
From: ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org (Eric W. Biederman)
Subject: Re: [PATCH 1/3] panic: Disable crash_kexec_post_notifiers if kdump is not available
Date: Fri, 10 Jul 2015 08:41:28 -0500
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	<20150710113331.4368.63745.stgit@softrs>
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	message of "Fri, 10 Jul 2015 20:33:31 +0900")
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To: Hidehiro Kawai <hidehiro.kawai.ez-FCd8Q96Dh0JBDgjK7y7TUQ@public.gmane.org>
Cc: Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>, Vivek Goyal <vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, linux-mips-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org, Baoquan He <bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, linux-sh-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-s390-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Ingo Molnar <mingo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, HATAYAMA Daisuke <d.hatayama-+CUm20s59erQFUHtdCDX3A@public.gmane.org>, Masami Hiramatsu <masami.hiramatsu.pt-FCd8Q96Dh0JBDgjK7y7TUQ@public.gmane.org>, Daniel Walker <dwalker-zu3NM2574RrQT0dZR+AlfA@public.gmane.org>, linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linux-metag-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org

Hidehiro Kawai <hidehiro.kawai.ez-FCd8Q96Dh0JBDgjK7y7TUQ@public.gmane.org> writes:

> You can call panic notifiers and kmsg dumpers before kdump by
> specifying "crash_kexec_post_notifiers" as a boot parameter.
> However, it doesn't make sense if kdump is not available.  In that
> case, disable "crash_kexec_post_notifiers" boot parameter so that
> you can't change the value of the parameter.

Nacked-by: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>

You are confusing kexec on panic and CONFIG_CRASH_DUMP
which is about the tools for reading the state of the previous kernel.

Eric

> Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez-FCd8Q96Dh0JBDgjK7y7TUQ@public.gmane.org>
> Cc: Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
> Cc: Eric Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
> Cc: Vivek Goyal <vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> ---
>  kernel/panic.c |    2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/kernel/panic.c b/kernel/panic.c
> index 04e91ff..5252331 100644
> --- a/kernel/panic.c
> +++ b/kernel/panic.c
> @@ -502,12 +502,14 @@ __visible void __stack_chk_fail(void)
>  core_param(pause_on_oops, pause_on_oops, int, 0644);
>  core_param(panic_on_warn, panic_on_warn, int, 0644);
>  
> +#ifdef CONFIG_CRASH_DUMP
>  static int __init setup_crash_kexec_post_notifiers(char *s)
>  {
>  	crash_kexec_post_notifiers = true;
>  	return 0;
>  }
>  early_param("crash_kexec_post_notifiers", setup_crash_kexec_post_notifiers);
> +#endif
>  
>  static int __init oops_setup(char *s)
>  {