Unable to handle kernel NULL pointer dereference with 2.4.27

Unable to handle kernel NULL pointer dereference with 2.4.27

[Cyril Bouthors]

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Hi,

I'm having this error several times a month on a heavy loaded production NFS server with RAID0:

Unable to handle kernel NULL pointer dereference at virtual address 00000020
 printing eip:
f884488e
*pde = 00000000
Oops: 0002
CPU:    0
EIP:    0010:[raid0:__insmod_raid0_O/lib/modules/2.4.27-1-686/kernel/drivers/md+-235378/96]    Not tainted
EFLAGS: 00010202
eax: f884d6a0   ebx: efd32600   ecx: 00000000   edx: 00000020
esi: efd32600   edi: c2825f5c   ebp: 00001ee2   esp: c2825f1c
ds: 0018   es: 0018   ss: 0018
Process kswapd (pid: 4, stackpage=c2825000)
Stack: efd32600 efd32600 c0153734 efd32600 efd32608 c015379d efd32600 f421cc28
       c0150018 c3581408 c35817c0 c35817c8 00000000 c0153a24 c2825f5c 00015d9c
       efd32428 f50ebdc8 000001d0 0000003c 00000015 c025d478 c0153bb4 00015d9c
Call Trace:    [clear_inode+196/224] [dispose_list+77/176] [__get_lease+488/608] [prune_icache+100/464] [shrink_icache_memory+36/64]
  [try_to_free_pages_zone+143/256] [kswapd_balance_pgdat+102/176] [kswapd_balance+40/64] [kswapd+152/185] [_stext+0/64] [arch_kernel_thread+46/64]
  [kswapd+0/185]

Code: ff 0a 0f 94 c0 84 c0 75 44 ba ff ff ff ff 89 93 8c 01 00 00
 <5>__alloc_pages: 0-order allocation failed (gfp=0xf0/0)

I'm running 2.4.27 compiled with Debian Sid options from the
kernel-image-2.4.27-1-686 package.

Is this a bug in raid0.c ?

Is there a way to fix this?

Thanks.
-- 
Cyril Bouthors

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Re: Unable to handle kernel NULL pointer dereference with 2.4.27

[Neil Brown]

On Monday November 29, cyril@bouthors.org wrote:
> Hi,
> 
> I'm having this error several times a month on a heavy loaded production NFS server with RAID0:
> 
> Unable to handle kernel NULL pointer dereference at virtual address 00000020
>  printing eip:
> f884488e
> *pde = 00000000
> Oops: 0002
> CPU:    0
> EIP:    0010:[raid0:__insmod_raid0_O/lib/modules/2.4.27-1-686/kernel/drivers/md+-235378/96]    Not tainted
> EFLAGS: 00010202
> eax: f884d6a0   ebx: efd32600   ecx: 00000000   edx: 00000020
> esi: efd32600   edi: c2825f5c   ebp: 00001ee2   esp: c2825f1c
> ds: 0018   es: 0018   ss: 0018
> Process kswapd (pid: 4, stackpage=c2825000)
> Stack: efd32600 efd32600 c0153734 efd32600 efd32608 c015379d efd32600 f421cc28
>        c0150018 c3581408 c35817c0 c35817c8 00000000 c0153a24 c2825f5c 00015d9c
>        efd32428 f50ebdc8 000001d0 0000003c 00000015 c025d478 c0153bb4 00015d9c
> Call Trace:    [clear_inode+196/224] [dispose_list+77/176] [__get_lease+488/608] [prune_icache+100/464] [shrink_icache_memory+36/64]
>   [try_to_free_pages_zone+143/256] [kswapd_balance_pgdat+102/176] [kswapd_balance+40/64] [kswapd+152/185] [_stext+0/64] [arch_kernel_thread+46/64]
>   [kswapd+0/185]
> 
> Code: ff 0a 0f 94 c0 84 c0 75 44 ba ff ff ff ff 89 93 8c 01 00 00
>  <5>__alloc_pages: 0-order allocation failed (gfp=0xf0/0)
> 
> I'm running 2.4.27 compiled with Debian Sid options from the
> kernel-image-2.4.27-1-686 package.
> 
> Is this a bug in raid0.c ?

No.  The reference to raid0 is purely accidental - the offset into
raid0 that is mentioned is -235378 : a negative number !!!!

> 
> Is there a way to fix this?

I suspect that it is a filesystem problem.
I recommend reporting the problem to linux-kernel@vger.kernel.org and
mentioning what filesystem you are using.

NeilBrown

> 
> Thanks.
> -- 
> Cyril Bouthors

Re: Unable to handle kernel NULL pointer dereference with 2.4.27

[Cyril Bouthors]

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On 30 Nov 2004, Neil Brown wrote:
> No.  The reference to raid0 is purely accidental - the offset into
> raid0 that is mentioned is -235378 : a negative number !!!!

Sorry about that.

> I suspect that it is a filesystem problem.
> I recommend reporting the problem to linux-kernel@vger.kernel.org
> and mentioning what filesystem you are using.

I will.

Thanks.
-- 
Cyril Bouthors

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