linux-kernel - Re: [PATCH] vsprintf: Neaten %pK kptr_restrict, save a bit of code space

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Message-Id: <20110119151613.cfbd7bb3.akpm@linux-foundation.org>
Date:	Wed, 19 Jan 2011 15:16:13 -0800
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Joe Perches <joe@...ches.com>
Cc:	Dan Rosenberg <drosenberg@...curity.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] vsprintf: Neaten %pK kptr_restrict, save a bit of code
 space

On Wed, 19 Jan 2011 15:11:02 -0800
Joe Perches <joe@...ches.com> wrote:

> On Wed, 2011-01-19 at 14:50 -0800, Andrew Morton wrote:
> > On Thu, 13 Jan 2011 12:21:12 -0800
> > Joe Perches <joe@...ches.com> wrote:
> > > If kptr restrictions are on, just set the passed pointer to NULL.
> > > diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> []
> > > +		if (!((kptr_restrict == 0) ||
> > > +		      (kptr_restrict == 1 &&
> > > +		       has_capability_noaudit(current, CAP_SYSLOG))))
> > > +			ptr = NULL;
> > > +		break;
> > This hurts my brain.   Does it work?
> 
> Some say mentally challenging puzzles help deter/delay
> onset of cognitive decline/Alzheimer's.  See: www.dakim.com
> 
> A mentally less challenging perhaps cleaner form is:
> 
> 		if (kptr_restrict == 0)
> 			break;
> 		if (kptr_restrict == 1 &&
> 		    has_capability_noaudit(current, CAP_SYSLOG))
> 			break;
> 		ptr = NULL;
> 		break;
> 
> Your choice. ;)

That wasn't the bit which hurt.

You still haven't told me if it works.  How thoroughly was it tested?
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