Thread (10 messages) 10 messages, 5 authors, 2011-09-06

analysis of kernel panic logs.

From: sandeep kumar <hidden>
Date: 2011-09-05 05:51:19

Hi Dave,

The problem is solved.
But i have one doubt.
So the PC is 0, and the LR is C92F. That tells me that the code at
C92F in your init process is trying to call a function through a NULL
pointer. You can try disassembling your init process. Something like
arm-eabi-objdump --disassemble init
In this case we came to know the process name 'init'. But in some
cases we might just have the link register address, and no process name.
say some user-space process has caused the panic.

Can u tell me ..how to debug in that case?

Thank you so much..
Sandeep




On Fri, Sep 2, 2011 at 8:43 PM, Dave Hylands [off-list ref] wrote:
Hi Sandeep,

On Fri, Sep 2, 2011 at 4:11 AM, sandeep kumar [off-list ref]
wrote:
quoted
Logs after enabling the CONFIG_DEBUG_USER and setting user_debug to 255,
to
quoted
get more info....(as suggested by Dave..)

<3>[   89.663286] init: [boot time] processing action 0x4c5e8
(property:init.svc.samsungani=stopped)
<3>[   89.663988] init: [boot time] processing action 0x4ef20
(property:init.svc.samsungani=stopped)
<7>[   89.664049] init: unhandled page fault (11) at 0x00000000, code
0x80000007
<1>[   89.664080] pgd = de370000
<1>[   89.664110] [00000000] *pgd=5eb83031, *pte=00000000, *ppte=00000000
<4>[   89.664141]
<4>[   89.664171] Pid: 1, comm:                 init
<4>[   89.664202] CPU: 1    Not tainted  (2.6.35.11 #4)
<4>[   89.664232] PC is at 0x0
<4>[   89.664232] LR is at 0xc92f
<4>[   89.664263] pc : [<00000000>]    lr : [<0000c92f>]    psr: 60000010
So the PC is 0, and the LR is C92F. That tells me that the code at
C92F in your init process is trying to call a function through a NULL
pointer. You can try disassembling your init process. Something like

arm-eabi-objdump --disassemble init

You'll need to figure out which toolchain was used to compile the init
process. I'm jjust taking a guess that it was arm-eabi-gcc.

You may need to recompile with debug symbols or dig up the unstripped
executable from your build.

--
Dave Hylands
Shuswap, BC, Canada
http://www.davehylands.com


-- 
With regards,
Sandeep Kumar Anantapalli,
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