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Date:   Wed, 27 Oct 2021 13:42:38 +0200 (CEST)
From:   Miroslav Benes <mbenes@suse.cz>
To:     Ming Lei <ming.lei@redhat.com>
cc:     Petr Mladek <pmladek@suse.com>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>, tj@kernel.org,
        gregkh@linuxfoundation.org, akpm@linux-foundation.org,
        minchan@kernel.org, jeyu@kernel.org, shuah@kernel.org,
        bvanassche@acm.org, dan.j.williams@intel.com, joe@perches.com,
        tglx@linutronix.de, keescook@chromium.org, rostedt@goodmis.org,
        linux-spdx@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
        live-patching@vger.kernel.org
Subject: Re: [PATCH v8 11/12] zram: fix crashes with cpu hotplug multistate
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> > 
> > The livepatch code uses workqueue because the livepatch can be
> > disabled via sysfs interface. It obviously could not wait until
> > the sysfs interface is removed in the sysfs write() callback
> > that triggered the removal.
> 
> If klp_free_patch_* is moved into module_exit() and not let enable
> store() to kill kobjects, all kobjects can be deleted in module_exit(),
> then wait_for_completion(patch->finish) may be removed, also wq isn't
> required for the async cleanup.

It sounds like a nice cleanup. If we combine kobject_del() to prevent any 
show()/store() accesses and free everything later in module_exit(), it 
could work. If I am not missing something around how we maintain internal 
lists of live patches and their modules.

Thanks

Miroslav