linux-kernel - Re: [PATCH v7 2/3] trivial: PM / Hibernate: clean up checkpatch in hibernate.c

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Date:	Wed, 05 Feb 2014 01:03:29 +0100
From:	"Rafael J. Wysocki" <rjw@...ysocki.net>
To:	Sebastian Capella <sebastian.capella@...aro.org>
Cc:	linux-kernel@...r.kernel.org, linux-mm@...ck.org,
	linux-pm@...r.kernel.org, linaro-kernel@...ts.linaro.org,
	patches@...aro.org, Pavel Machek <pavel@....cz>,
	Len Brown <len.brown@...el.com>
Subject: Re: [PATCH v7 2/3] trivial: PM / Hibernate: clean up checkpatch in hibernate.c

On Tuesday, February 04, 2014 03:22:22 PM Sebastian Capella wrote:
> Quoting Sebastian Capella (2014-02-04 14:37:33)
> > Quoting Rafael J. Wysocki (2014-02-04 13:36:29)
> > > >  static int __init resumedelay_setup(char *str)
> > > >  {
> > > > -     resume_delay = simple_strtoul(str, NULL, 0);
> > > > +     int ret = kstrtoint(str, 0, &resume_delay);
> > > > +     /* mask must_check warn; on failure, leaves resume_delay unchanged */
> > > > +     (void)ret;
> 
> One unintended consequence of this change is that it'll now accept a
> negative integer parameter.

Well, what about using kstrtouint(), then?

> I'll rework this to have the same behavior as before.
> 
> BTW, one question, is the __must_check really needed on kstrtoint?
> Wouldn't it be acceptable to rely on kstrtoint to not update resume_delay
> if it's unable to parse an integer out of the string?  Couldn't that be
> a sufficient effect without requiring checking the return?

Well, kstrtoint() is used in some security-sensitive places AFAICS, so it
really is better to check its return value in general.  The __must_check
reminds people about that.

Thanks!

-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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