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Date: Wed, 16 Aug 2017 16:50:07 +0200
From: Petr Mladek <pmladek@suse.com>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Miroslav Benes <mbenes@suse.cz>, jeyu@kernel.org, jikos@kernel.org,
        lpechacek@suse.cz, live-patching@vger.kernel.org,
        linux-kernel@vger.kernel.org, Andy Lutomirski <luto@kernel.org>,
        "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
        Michael Ellerman <mpe@ellerman.id.au>, Oleg Nesterov <oleg@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH v2 0/3] livepatch: Introduce force sysfs attribute
Message-ID: <20170816145007.GD601@pathway.suse.cz>
References: <20170810104815.14727-1-mbenes@suse.cz>
 <20170811211131.n7mo4xsucteba7hz@treble>
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On Fri 2017-08-11 16:11:31, Josh Poimboeuf wrote:
> On Thu, Aug 10, 2017 at 12:48:12PM +0200, Miroslav Benes wrote:
> > Now there is a sysfs attribute called "force", which provides two
> > functionalities, "signal" and "force" (previously "unmark"). I haven't
> > managed to come up with better names. Proposals are welcome. On the
> > other hand I do not mind it much.
> 
> Now "force" has two meanings, which is a little confusing.  What do you
> think about just having two separate write-only sysfs flags?
> 
>   echo 1 > /sys/kernel/livepatch/signal
>   echo 1 > /sys/kernel/livepatch/force

I like the simplicity but I wonder if there might be more actions
that need to be forced in the future. Then this might cause
confusion.

For example, we have force_module_load attribute in kGraft.
It allows to load a module even when it is refused by a livepatch.
It is handy when there is a harmless bug in the patch.

Best Regards,
Petr