From: Pekka Enberg <penberg@kernel.org>
To: Christoph Lameter <cl@linux.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
glommer@parallels.com, linux-kernel@vger.kernel.org
Subject: Re: [linux-next-20130422] Bug in SLAB?
Date: Wed, 01 May 2013 11:05:20 +0300 [thread overview]
Message-ID: <5180CCC0.8070703@kernel.org> (raw)
In-Reply-To: <0000013e5bfc7c4d-54fa9464-dccd-4157-b4a5-22594261eaf3-000000@email.amazonses.com>
On 4/30/13 8:27 PM, Christoph Lameter wrote:
>> "kmalloc() returning NULL for these allocations" is needed by "try kmalloc()
>> first, fallback to vmalloc()" allocation. There are kernel modules which expect
>> kmalloc() to return NULL rather than oops when the requested size is larger
>> than KMALLOC_MAX_SIZE bytes. If kmalloc() suddenly starts triggering oops, such
>> modules will break.
>
> This behavior has been in there for years. Why try a kmalloc that
> always fails since the size is too big?
...because want the extra protection for cases where size is controlled
by userspace. This is consistent with kcalloc() that returns NULL on
integer overflow.
Pekka
next prev parent reply other threads:[~2013-05-01 8:05 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-24 12:08 [linux-next-20130422] Bug in bootup code or debug code? Tetsuo Handa
2013-04-25 12:20 ` [linux-next-20130422] Bug in SLAB? Tetsuo Handa
2013-04-29 2:40 ` Tetsuo Handa
2013-04-29 10:12 ` Pekka Enberg
2013-04-29 14:44 ` Glauber Costa
2013-04-29 14:59 ` Christoph Lameter
2013-04-29 15:16 ` Glauber Costa
2013-04-29 15:46 ` Christoph Lameter
2013-04-29 15:54 ` Glauber Costa
2013-04-29 15:28 ` Tetsuo Handa
2013-04-29 16:16 ` Tetsuo Handa
2013-05-09 12:25 ` Tetsuo Handa
2013-05-09 14:14 ` Christoph Lameter
2013-05-09 21:54 ` Tetsuo Handa
2013-05-10 12:38 ` Tetsuo Handa
2013-05-10 15:57 ` Christoph Lameter
[not found] ` <201305272153.HEH51089.OHFQMOOtFLSFVJ@I-love.SAKURA.ne.jp>
2013-06-17 11:59 ` Tetsuo Handa
2013-04-29 17:48 ` Christoph Lameter
2013-04-29 21:45 ` Tetsuo Handa
2013-04-30 14:26 ` Christoph Lameter
2013-04-30 16:01 ` Tetsuo Handa
2013-04-30 17:27 ` Christoph Lameter
2013-05-01 8:05 ` Pekka Enberg [this message]
2013-05-02 15:12 ` Christoph Lameter
2013-05-01 12:14 ` Tetsuo Handa
2013-05-02 11:51 ` Tetsuo Handa
2013-05-02 20:53 ` Christoph Lameter
2013-05-03 8:26 ` Tetsuo Handa
2013-05-03 15:43 ` Christoph Lameter
2013-05-06 6:59 ` Geert Uytterhoeven
2013-05-06 7:27 ` Pekka Enberg
2013-05-03 18:04 ` Christoph Lameter
2013-05-03 18:48 ` Tetsuo Handa
2013-05-03 19:21 ` Christoph Lameter
2013-05-04 0:15 ` Tetsuo Handa
2013-05-06 13:46 ` Christoph Lameter
2013-05-07 10:38 ` Tetsuo Handa
2013-05-07 14:28 ` Christoph Lameter
2013-07-01 20:09 ` Andrew Morton
2013-07-01 21:45 ` Tetsuo Handa
2013-07-01 21:53 ` Andrew Morton
2013-07-02 12:49 ` Tetsuo Handa
2013-07-02 19:12 ` Andrew Morton
2013-07-07 15:58 ` Pekka Enberg
2013-05-06 6:32 ` Pekka Enberg
2013-05-06 13:47 ` Christoph Lameter
2013-05-06 20:24 ` Pekka Enberg
2013-05-07 14:23 ` Christoph Lameter
2013-05-07 14:44 ` Pekka Enberg
2013-05-07 15:40 ` Christoph Lameter
2013-04-30 14:34 ` Christoph Lameter
2013-05-01 8:03 ` Pekka Enberg
2013-05-02 15:13 ` Christoph Lameter
2013-04-30 15:16 ` Fix off by one error in slab.h Christoph Lameter
2013-04-29 2:56 ` [linux-next-20130422] Bug in SLAB? Zhan Jianyu
2013-04-29 2:56 ` Zhan Jianyu
2013-04-29 3:56 ` Tetsuo Handa
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