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To:     "Guilherme G. Piccoli" <gpiccoli@igalia.com>,
        "kexec@lists.infradead.org" <kexec@lists.infradead.org>,
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        "kernel@gpiccoli.net" <kernel@gpiccoli.net>,
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Subject: Re: [PATCH V4] notifier/panic: Introduce panic_notifier_filter
Thread-Topic: [PATCH V4] notifier/panic: Introduce panic_notifier_filter
Thread-Index: AQHYBKVl3QVmCewphUe4SBvooFofu6xzugqqgAAMboCAAAhAVg==
Date:   Tue, 25 Jan 2022 13:06:47 +0000
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> Hi, thanks for the review. First of all, notice that it's very likely=0A=
> this patch isn't gonna get merged this way, we are considering a=0A=
> refactor that included 2 panic notifiers: one a bit earlier (pre_dump),=
=0A=
> that includes functions less risky, as watchdog unloaders, kernel offset=
=0A=
> dump, etc, and the second panic notifier (post_dump) will keep the=0A=
> majority of callbacks, and can be conditionally executed on kdump=0A=
> through the usage of "crash_kexec_post_notifiers".=0A=
=0A=
But the pre_dump cannot avoid calling multiple unnecessary handlers, right?=
=0A=
It's more risky than the previous idea...=0A=
=0A=
> Anyway, I'm curious with your code review - how can we use this filter=0A=
> with modules, if the filter setup is invoked as early_param(), before=0A=
> modules load? In that case, module functions won't have a valid address,=
=0A=
> correct? So, in that moment, this lookup fails, we cannot record an=0A=
> unloaded module address in such list. Please, correct me if I'm wrong.=0A=
=0A=
For example, how about simply maintaining function symbol names in the list=
=0A=
as string, not address.=0A=
=0A=
Thanks.=0A=
HATAYAMA, Daisuke=0A=