RE: [PATCH v2] kernel/panic: Add "crash_kexec_post_notifiers" option for kdump after panic_notifers

From: Motohiro Kosaki
Date: Thu Apr 17 2014 - 11:14:16 EST




> -----Original Message-----
> From: Masami Hiramatsu [mailto:masami.hiramatsu.pt@xxxxxxxxxxx]
> Sent: Wednesday, April 16, 2014 8:13 PM
> To: linux-kernel@xxxxxxxxxxxxxxx; Vivek Goyal; Eric Biederman
> Cc: Andrew Morton; Yoshihiro YUNOMAE; Satoru MORIYA; Motohiro Kosaki; Tomoki Sekiyama
> Subject: [PATCH v2] kernel/panic: Add "crash_kexec_post_notifiers" option for kdump after panic_notifers
>
> Add a "crash_kexec_post_notifiers" option to run kdump after running panic_notifiers and dump kmsg. This can help rare situations
> which kdump drops in failure because of unstable crashed kernel or hardware failure (memory corruption on critical data/code), or
> the 2nd kernel is already broken by the 1st kernel (it's a broken behavior, but who can guarantee that the "crashed" kernel works
> correctly?).
>
> Usage: add "crash_kexec_post_notifiers" to kernel boot option.
>
> Note that this actually increases risks of the failure of kdump.
> This option should be set only if you worry about the rare case of kdump failure rather than increasing the chance of success.
>
> Changes from v1:
> - Rename late_kdump option to crash_kexec_post_notifiers.
> - Remove unneeded warning message.
>
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
> Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
> Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@xxxxxxxxxxx>
> Cc: Satoru MORIYA <satoru.moriya.br@xxxxxxxxxxx>
> Cc: Motohiro Kosaki <Motohiro.Kosaki@xxxxxxxxxxxxxx>
> Cc: Tomoki Sekiyama <tomoki.sekiyama@xxxxxxx>

I have no objection.
Acked-by: KOSAKI Motohiro <Kosaki.motohiro@xxxxxxxxxxxxxx>