[PATCH v3] Crash: add lock to serialize crash hotplug handling

[Andrew Morton]

On Tue, 26 Sep 2023 20:09:05 +0800 Baoquan He <bhe at redhat.com> wrote:

> Eric reported that handling corresponding crash hotplug event can be
> failed easily when many memory hotplug event are notified in a short
> period. They failed because failing to take __kexec_lock.

I'm assuming that this failure is sufficiently likely so as to  justify a -stable
backport of the fix.   Please let me know if this is incorrect.