From: Jason Uhlenkott <jasonuhl@jasonuhl.org>
To: Jan Engelhardt <jengelh@computergmbh.de>
Cc: Rene Herman <rene.herman@gmail.com>,
Arjan van de Ven <arjan@infradead.org>,
Tim Bird <tim.bird@am.sony.com>,
linux kernel <linux-kernel@vger.kernel.org>
Subject: Re: kfree(0) - ok?
Date: Wed, 15 Aug 2007 02:43:56 -0700 [thread overview]
Message-ID: <20070815094356.GA18253@aurum.uhlenkott.net> (raw)
In-Reply-To: <Pine.LNX.4.64.0708151113410.19270@fbirervta.pbzchgretzou.qr>
On Wed, Aug 15, 2007 at 11:20:33 +0200, Jan Engelhardt wrote:
>
> On Aug 15 2007 10:37, Rene Herman wrote:
> > On 08/15/2007 09:28 AM, Jan Engelhardt wrote:
> >> On Aug 14 2007 16:21, Jason Uhlenkott wrote:
> >
> >> > On Tue, Aug 14, 2007 at 15:55:48 -0700, Arjan van de Ven wrote:
> >> > > NULL is not 0 though.
> >> > It is. Its representation isn't guaranteed to be all-bits-zero,
> >>
> >> C guarantees that.
> >
> > C guarantees what? If you're disagreeing with Jason -- he's right.
>
> http://coding.derkeiler.com/Archive/C_CPP/comp.lang.c/2003-11/1808.html
That's about representation of integers types. Pointer types are
another matter.
C99 sections 6.2.5 and 6.2.6 cover this.
This is all just academic language lawyering, of course. Any machine
on which a pointer isn't NULL after being memset to 0 has serious
quality of implementation issues.
next prev parent reply other threads:[~2007-08-15 9:44 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-08-14 22:59 Tim Bird
2007-08-14 22:55 ` Arjan van de Ven
2007-08-14 23:21 ` Jason Uhlenkott
2007-08-15 7:28 ` Jan Engelhardt
2007-08-15 8:37 ` Rene Herman
2007-08-15 9:20 ` Jan Engelhardt
2007-08-15 9:43 ` Jason Uhlenkott [this message]
2007-08-15 9:58 ` Rene Herman
2007-08-15 10:20 ` Jan Engelhardt
2007-08-15 10:27 ` Rene Herman
2007-08-15 13:58 ` Kyle Moffett
2007-08-15 14:06 ` Jan Engelhardt
2007-08-15 14:34 ` Kyle Moffett
2007-08-15 16:01 ` H. Peter Anvin
2007-08-15 8:52 ` Jason Uhlenkott
2007-08-15 9:18 ` Andreas Schwab
2007-08-15 9:32 ` Giacomo A. Catenazzi
2007-08-14 23:42 ` Satyam Sharma
2007-08-15 0:19 ` Christoph Lameter
2007-08-17 18:22 ` Andrew Morton
2007-08-17 18:31 ` Arjan van de Ven
2007-08-17 18:50 ` Satyam Sharma
2007-08-17 18:37 ` Jan Engelhardt
2007-08-17 20:43 ` Christoph Lameter
2007-08-17 21:17 ` Satyam Sharma
2007-08-17 21:32 ` Satyam Sharma
2007-08-17 21:13 ` Satyam Sharma
2007-08-17 21:14 ` Christoph Lameter
2007-08-17 21:42 ` Pekka Enberg
2007-08-17 23:22 ` Christoph Lameter
2007-08-17 23:40 ` Thomas Gleixner
2007-08-18 0:02 ` Satyam Sharma
2007-08-18 1:03 ` Christoph Lameter
2007-08-18 8:10 ` Pekka Enberg
2007-08-18 8:21 ` Jan Engelhardt
2007-08-17 21:46 ` Satyam Sharma
2007-08-14 23:13 ` Satyam Sharma
[not found] <fa.oMJ6o9vN0dnAoFR83/o4hg1EptE@ifi.uio.no>
2007-08-14 23:05 ` Robert Hancock
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