Re: [PATCH v2 1/3] livepatch: Add force sysfs attribute

From: Miroslav Benes <mbenes@suse.cz>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: jeyu@kernel.org, jikos@kernel.org, pmladek@suse.com,
	lpechacek@suse.cz, live-patching@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/3] livepatch: Add force sysfs attribute
Date: Mon, 14 Aug 2017 16:03:49 +0200 (CEST)	[thread overview]
Message-ID: <alpine.LSU.2.20.1708141600240.31485@pobox.suse.cz> (raw)
In-Reply-To: <20170811211321.uwn4clccx6pjnbxw@treble>

On Fri, 11 Aug 2017, Josh Poimboeuf wrote:

> On Thu, Aug 10, 2017 at 12:48:13PM +0200, Miroslav Benes wrote:
> > +static ssize_t force_store(struct kobject *kobj, struct kobj_attribute *attr,
> > +			   const char *buf, size_t count)
> > +{
> > +	/*
> > +	 * klp_mutex lock is not grabbed here intentionally. It is not really
> > +	 * needed. The race window is harmless and grabbing the lock would only
> > +	 * hold the action back.
> > +	 */
> > +	if (!klp_transition_patch) {
> > +		pr_info("no patching in progress, forced action ineffective\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	return -EINVAL;
> > +}
> 
> I think this is really a minor issue, and the -EINVAL is enough.  As the
> comment says, the race window is harmless.  So I'd say there's no need
> to scare the user with a printk.

Ok, I'll remove it in v3.

Miroslav