linux-kernel - Re: [PATCH] CodingStyle: Clarify and complete chapter 7

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Message-ID: <20160814144543.1a12bced@lwn.net>
Date:	Sun, 14 Aug 2016 14:45:43 -0600
From:	Jonathan Corbet <corbet@....net>
To:	Mark D Rustad <mrustad@...il.com>
Cc:	Jean Delvare <jdelvare@...e.de>, linux-doc@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Markus Elfring <elfring@...rs.sourceforge.net>
Subject: Re: [PATCH] CodingStyle: Clarify and complete chapter 7

On Sun, 14 Aug 2016 13:12:33 -0700
Mark D Rustad <mrustad@...il.com> wrote:

> >> +	 err:
> >>  		kfree(foo->bar);
> >>  		kfree(foo);
> >>  		return ret;
> >>
> >>  The bug in this code is that on some exit paths "foo" is NULL.  Normally the  
> >
> > ...except that kfree() can handle null pointers just fine, so this isn't
> > actually a bug, right?  Someday when somebody has time it would be good to
> > come up with a better example.  
> 
> But if foo is NULL, foo->bar is not NULL and so kfree will have a problem  
> with it. So this is a bug.

Oops, sigh, duh.  OK, ignore me. (Though technically kfree will not have a
problem with it, since things won't get that far.. :)

jon