Re: [PATCH] Only allow to set crash_kexec_post_notifiers on boot time

From: Andrew Morton
Date: Fri Sep 18 2020 - 20:47:47 EST

On Fri, 18 Sep 2020 11:25:46 +0800 Dave Young <dyoung@xxxxxxxxxx> wrote:

> crash_kexec_post_notifiers enables running various panic notifier
> before kdump kernel booting. This increases risks of kdump failure.
> It is well documented in kernel-parameters.txt. We do not suggest
> people to enable it together with kdump unless he/she is really sure.
> This is also not suggested to be enabled by default when users are
> not aware in distributions.
> But unfortunately it is enabled by default in systemd, see below
> discussions in a systemd report, we can not convince systemd to change
> it:
> Actually we have got reports about kdump kernel hangs in both s390x
> and powerpcle cases caused by the systemd change, also some x86 cases
> could also be caused by the same (although that is in Hyper-V code
> instead of systemd, that need to be addressed separately).
> Thus to avoid the auto enablement here just disable the param writable
> permission in sysfs.

Well. I don't think this is at all a desirable way of resolving a
disagreement with the systemd developers

At the above github address I'm seeing "ryncsn added a commit to
ryncsn/systemd that referenced this issue 9 days ago", "pstore: don't
enable crash_kexec_post_notifiers by default". So didn't that address
the issue?