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Date: Fri, 28 Jul 2017 13:29:00 -0500
From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Petr Mladek <pmladek@suse.com>, live-patching@vger.kernel.org,
        linux-kernel@vger.kernel.org, Jessica Yu <jeyu@kernel.org>,
        Jiri Kosina <jikos@kernel.org>, Miroslav Benes <mbenes@suse.cz>,
        Chris J Arges <chris.j.arges@canonical.com>
Subject: Re: [PATCH] livepatch: add (un)patch hooks
Message-ID: <20170728182900.7ea7dnnvditaestd@treble>
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On Fri, Jul 28, 2017 at 02:08:33PM -0400, Joe Lawrence wrote:
> On 07/27/2017 05:36 PM, Josh Poimboeuf wrote:
> > On Thu, Jul 27, 2017 at 04:43:58PM -0400, Joe Lawrence wrote:
> >> On 07/20/2017 12:17 AM, Josh Poimboeuf wrote:
> >>> - The post-patch and post-unpatch hooks will need to be run from either
> >>>   klp_complete_transition() or klp_module_coming/going(), depending on
> >>>   whether the to-be-patched module is already loaded or is being
> >>>   loaded/unloaded.
> >>
> >> You're suggesting that post-(un)patch-hooks:
> >>
> >>   1 - Notify klp_objects when a KLP_(UN)PATCHED transition completes
> > 
> > Right. (From klp_complete_transition())
> 
> We should be careful to only call hooks for those klp_objects that were
> actually (un)patched.  I don't think there is such state that makes it
> all the way out to klp_complete_transition(), but since both the
> completion and module_coming/going code both operate under the
> klp_mutex, perhaps klp_is_object_loaded() is a sufficient check?

Yeah, the mutex makes it safe to just check klp_is_object_loaded().

-- 
Josh