Debug Kernel Modules With KGDB

[Raghavendra]

Hi Zhang,

On Monday 01 December 2014 04:32 PM, Freeman Zhang wrote:
> Hi Raghavendra,
>
> Thanks for your reply, but `sudo` doesn't solve the problem :(
Well then I guess 'sudo' isn't implemented in android. Any way, 
ultimately you may wan't to login as root and then try reading the file 
in order to get the address.
Regards,
Raghavendra
>
> All the best!
>
> Freeman Zhang
>
> -------- Original Message --------
>> On Monday 01 December 2014 03:26 PM, Freeman Zhang wrote:
>>> Hi list,
>>>
>>> I've been trying to setup a debug environment for linux
>>> kernel(v3.4,Android,ARM) with kgdb. It worked fine untill I tried to use
>>> it to debug a module. Under the instruction from LDD, I add module debug
>>> info in gdb with command:
>>>
>>>      add-symbol-file test-module.ko  address
>>>
>>> LDD uses `cat /sys/module/test-module/sections/.text` to get the address
>>> where the module has been loaded. However, I got:
>>>      
>>>      0x00000000
>> Try reading the file as a root.
>> $ sudo cat /sys/module/test-module/sections/.text
>>> When I use `lsmod`, I got:
>>>
>>>      test-module 15278 0 - Live 0x00000000 (O)
>>>
>>> Why nothing but 0x00000000 ??
>>>
>>> So I have to do some research in kernel/module.c, and find out that
>>> struct module -> module_core = 0xbf000000. But when I try these in gdb:
>>>
>>>      add-symbol-file test-module.ko  0xbf000000
>>>      break one_of_my_function
>>>
>>> I got:
>>>
>>>      Cannot access memory at address 0xbf002350
>>>
>>> :(
>>> Could somebody help?
>>>
>>>
>>> All the best!
>>> Freeman Zhang
>>>
>>>      
>>>      
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> Kernelnewbies mailing list
>>> Kernelnewbies at kernelnewbies.org
>>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>>
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