From: Pekka Enberg <penberg@cs.helsinki.fi>
To: Christoph Lameter <clameter@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org,
Jeremy Fitzhardinge <jeremy@goop.org>
Subject: Re: SLUB: Return ZERO_SIZE_PTR for kmalloc(0)
Date: Tue, 05 Jun 2007 08:27:40 +0300 [thread overview]
Message-ID: <4664F44C.4040206@cs.helsinki.fi> (raw)
In-Reply-To: <Pine.LNX.4.64.0706041607560.27346@schroedinger.engr.sgi.com>
Christoph Lameter wrote:
> SLUB: Return ZERO_SIZE_PTR for kmalloc(0) V3
>
> Instead of returning the smallest available object return ZERO_SIZE_PTR.
>
> A ZERO_SIZE_PTR can be legitimately used as an object pointer as long
> as it is not deferenced. The dereference of ZERO_SIZE_PTR causes a
> distinctive fault.
> kfree can handle a ZERO_SIZE_PTR in the same way as NULL.
FWIW, I am happy :-). We should add a comment to kmalloc() that we
return non-unique pointers for zero-length allocations though.
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
next prev parent reply other threads:[~2007-06-05 5:27 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-06-02 1:37 SLUB: Return ZERO_SIZE_PTR for kmalloc(0) Christoph Lameter
2007-06-02 2:09 ` John Anthony Kazos Jr.
2007-06-02 2:15 ` Christoph Lameter
2007-06-02 2:21 ` John Anthony Kazos Jr.
2007-06-02 2:54 ` Linus Torvalds
2007-06-02 3:06 ` Christoph Lameter
2007-06-02 3:41 ` Andrew Morton
2007-06-02 4:01 ` Christoph Lameter
2007-06-02 4:31 ` Andrew Morton
2007-06-02 4:45 ` Christoph Lameter
2007-06-02 4:54 ` Andrew Morton
2007-06-03 16:17 ` Matt Mackall
2007-06-04 17:59 ` William Lee Irwin III
2007-06-03 16:15 ` Matt Mackall
2007-06-04 14:44 ` Alan Cox
2007-06-04 15:08 ` Pekka Enberg
2007-06-04 16:16 ` Christoph Lameter
2007-06-04 16:22 ` Pekka Enberg
2007-06-04 16:26 ` Linus Torvalds
2007-06-04 16:32 ` Jeremy Fitzhardinge
2007-06-04 16:37 ` Pekka Enberg
2007-06-04 16:38 ` Jeremy Fitzhardinge
2007-06-04 16:43 ` Roland Dreier
2007-06-04 17:02 ` Pekka Enberg
2007-06-04 16:48 ` Linus Torvalds
2007-06-04 18:22 ` Cyrill Gorcunov
2007-06-04 17:20 ` Alan Cox
2007-06-04 17:50 ` Linus Torvalds
2007-06-04 18:05 ` William Lee Irwin III
2007-06-04 18:47 ` Linus Torvalds
2007-06-04 19:01 ` Christoph Lameter
2007-06-04 19:13 ` Pekka Enberg
2007-06-04 19:14 ` Christoph Lameter
2007-06-04 19:25 ` Pekka Enberg
2007-06-04 22:39 ` Christoph Lameter
2007-06-04 22:53 ` Andrew Morton
2007-06-04 23:09 ` Christoph Lameter
2007-06-05 5:27 ` Pekka Enberg [this message]
2007-06-05 17:23 ` Christoph Lameter
2007-06-05 8:50 ` Rene Herman
2007-06-05 12:07 ` John Anthony Kazos Jr.
2007-06-05 12:54 ` Rene Herman
2007-06-05 13:58 ` John Anthony Kazos Jr.
2007-06-05 14:32 ` Rene Herman
2007-06-05 19:07 ` Pekka Enberg
2007-06-05 14:40 ` Jeremy Fitzhardinge
2007-06-05 14:56 ` Rene Herman
2007-06-06 21:26 ` Pavel Machek
2007-06-06 21:58 ` Rene Herman
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