How to analyze kernel Oops dump

[Mark Einon]

On 6 February 2013 14:44, Mark Einon <mark.einon at gmail.com> wrote:
> On 5 February 2013 13:27, Manavendra Nath Manav <mnm.kernel at gmail.com> wrote:
>> I am running Linux 3.4.0 on embedded ARM target and getting following
>> Oops every-time. I am not able to pin-point the reason for crash and
>> which driver module triggered it. How can I decode the values in the
>> registers at the time of crash. It's showing all in hex.
>>
>> [  492.713897] ------------[ cut here ]------------
>> [  492.718841] WARNING: at mm/slub.c:3415 ksize+0x70/0xc4()
>> [  492.725311] ---[ end trace 90a5ae2bdb3ab657 ]---
>> [  492.915618] ------------[ cut here ]------------
>> [  492.920593] WARNING: at mm/slub.c:3415 ksize+0x70/0xc4()
>> [  492.927032] ---[ end trace 90a5ae2bdb3ab658 ]---
>> [  493.113464] Unable to handle kernel paging request at virtual
>> address f6b9f777
> <snip>
>> [  494.068664] Backtrace:
>> [  494.071289] [<80109434>] (__kmalloc_track_caller+0x0/0x1ec) from
>> [<80335ec0>] (__alloc_skb+0x60/0xfc)
>> [  494.081085] [<80335e60>] (__alloc_skb+0x0/0xfc) from [<80336530>]
>> (__netdev_alloc_skb+0x2c/0x54)
>> [  494.090423] [<80336504>] (__netdev_alloc_skb+0x0/0x54) from
>> [<7f078788>] (stmmac_poll+0x590/0x794 [stmmac])
>> [  494.100738]  r4:ed0b84c0 r3:00000000
>> [  494.104553] [<7f0781f8>] (stmmac_poll+0x0/0x794 [stmmac]) from

Also, btw, this looks like it's triggered by the stmmac network driver.

I would attempt to boot your board with no network attached (if
possible) to see if my previous theory that bad memory is the culprit.
If it is, I assume that eventually some other slub error caused by a
different module would cause an oops - but your board should last a
bit longer with no network attached.

Cheers,

Mark