From: Manfred Spraul <manfred@colorfullife.com>
To: pinotj@club-internet.fr
Cc: akpm@osdl.org, linux-kernel@vger.kernel.org
Subject: Re: [Oops] i386 mm/slab.c (cache_flusharray)
Date: Fri, 21 Nov 2003 19:58:04 +0100 [thread overview]
Message-ID: <3FBE603C.3020903@colorfullife.com> (raw)
In-Reply-To: <mnet1.1069438363.27768.pinotj@club-internet.fr>
[-- Attachment #1: Type: text/plain, Size: 1016 bytes --]
pinotj@club-internet.fr wrote:
>0. Increase verbosity of the printk (thanks to Manfred):
>(compilation of kernel)
>slab: double free detected in cache 'buffer_head', objp c4c8e3d8, objnr 10,
>slabp c4c8e000, s_mem c4c8e180, bufctl ffffffff.
>(compilation of firebird)
>slab: double free detected in cache 'pte_chain', objp c18a6600, objnr 10,
>slabp c18a6000, s_mem c18a6100, bufctl ffffffff.
>
>
The correct value for the bufctl would be 0xfffffffe - a single bit is
wrong, but OTHO 0xffffffff is also a valid value.
Two different caches are affected.
The addresses of the corrupted variable differ, the offset into the page
is identical. I think that rules out bad memory. That leaves a bug in
slab.c, a bad bit in the L1/L2 cache, or random pointer scribbling.
Jerome, could you try the attached patch? It changes the magic constants
that are used by slab.c. And please pay attention to the objnr: Is it
always objnr 10, slabp xxxxx000, or do you see other values as well?
--
Manfred
--
Manfred
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[-- Type: text/plain, Size: 496 bytes --]
--- 2.6/mm/slab.c 2003-11-18 18:18:20.000000000 +0100
+++ build-2.6/mm/slab.c 2003-11-21 19:50:02.000000000 +0100
@@ -153,9 +153,9 @@
* is less than 512 (PAGE_SIZE<<3), but greater than 256.
*/
-#define BUFCTL_END 0xffffFFFF
-#define BUFCTL_FREE 0xffffFFFE
-#define SLAB_LIMIT 0xffffFFFD
+#define BUFCTL_END 0xfeffFFFF
+#define BUFCTL_FREE 0xf7ffFFFE
+#define SLAB_LIMIT 0xf0ffFFFD
typedef unsigned int kmem_bufctl_t;
/* Max number of objs-per-slab for caches which use off-slab slabs.
next prev parent reply other threads:[~2003-11-21 19:14 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-11-21 18:12 Re: [Oops] i386 mm/slab.c (cache_flusharray) pinotj
2003-11-21 18:58 ` Manfred Spraul [this message]
2003-11-21 22:48 ` Linus Torvalds
-- strict thread matches above, loose matches on Subject: below --
2003-12-09 0:57 pinotj
2003-12-09 2:03 ` Nathan Scott
2003-12-09 7:21 ` Christoph Hellwig
2003-12-09 23:58 ` Nathan Scott
2003-12-12 19:00 ` Christoph Hellwig
2003-12-12 20:07 ` Manfred Spraul
2003-12-04 18:27 pinotj
2003-12-04 18:49 ` Linus Torvalds
2003-12-04 19:09 ` Linus Torvalds
2003-12-04 21:21 ` Nathan Scott
2003-12-05 7:14 ` Christoph Hellwig
2003-12-05 9:34 ` Nathan Scott
2003-12-05 14:22 ` Christoph Hellwig
2003-12-05 3:00 ` Nathan Scott
2003-12-05 6:40 ` Linus Torvalds
2003-12-04 19:19 ` Manfred Spraul
2003-12-04 21:26 ` Nathan Scott
2003-12-03 23:06 pinotj
2003-12-03 23:26 ` Linus Torvalds
2003-11-29 17:41 pinotj
2003-12-02 0:36 ` Linus Torvalds
2003-12-02 1:37 ` Nathan Scott
2003-12-02 6:44 ` Nathan Scott
2003-12-02 18:05 ` Mike Fedyk
2003-12-02 20:05 ` Nathan Scott
2003-11-27 18:42 pinotj
2003-11-27 18:55 ` Manfred Spraul
2003-12-02 1:03 ` Mike Fedyk
2003-11-25 17:30 pinotj
2003-11-25 22:51 ` Linus Torvalds
2003-11-27 18:07 ` Manfred Spraul
2003-11-22 7:47 Re: " pinotj
2003-11-22 10:55 ` Manfred Spraul
2003-11-20 1:50 pinotj
2003-11-20 2:09 ` Andrew Morton
2003-11-19 18:19 pinotj
2003-11-20 1:07 ` Andrew Morton
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