And another observation about debugging, it seems that 'step' and 'next'
do the same thing with kgdb:
***
Breakpoint 5, ath_pci_probe (pdev=0xdf8e6c00, id=0xe155f24c) at
/root/dev/madwifi-9999/ath/if_ath_pci.c:230
230 pci_disable_device(pdev);
***
I don't want to step in pci_disable_device function, I want to pass over
it, so I press 'next' command:
***
(kgdb) n
pci_disable_device (dev=0xdf8e6c00) at drivers/pci/pci.c:1018
1018 {
***
but as your see, I'm inside pci_disable_device function. I want to step
out, so I use 'finish' command:
***
(kgdb) finish
Run till exit from #0 pci_disable_device (dev=0xdf8e6c00) at
drivers/pci/pci.c:1018
Warning:
Cannot insert breakpoint 0.
Error accessing memory address 0xff6085c7: Unknown error 4294967295.
***
but it shows error. Of course I can work without it, using my own
breakpoints, but it is inconvinient.
Regards,
Dmitry.
Dmitry Mikhin wrote:
> Hello,
>
> I solved the problem, it was my mistake.
> In first case breakpoint doesn't work because I haven't executed 'info
> shared'.
> In second case breakpoint doesn't work, because of 'rmmod and modprobe
> again' -
> this operation clears all SW breakpoints hooks on target.
>
> So I inserted sleep operation before ath_attach function:
> ***
> set_current_state(TASK_INTERRUPTIBLE);
> schedule_timeout (15000);
> ***
> During this sleep operation I'm connecting to target, executing info
> shared, and then
> setting breakpoint on ath_attach, and finally it works :)
>
> Regards,
> Dmitry.
>
> Caz Yokoyama wrote:
>> Hello Dmitry,
>> Please clarify if you can set a break point after "info shared". It is
>> known
>> that symbol reading is done on "info shared". -caz
>>
>> -----Original Message-----
>> From: Dmitry Mikhin [mailto:[email protected]] Sent: Wednesday, April
>> 29, 2009 9:32 AM
>> To: Mithlesh Thukral
>> Cc: [email protected]; Caz Yokoyama
>> Subject: Re: [Kgdb-bugreport] debugging kernel modules with kgdb-light in
>> 2.6.29.1
>>
>> Thanks Mithlesh, it helps me.
>>
>> Caz, but after series of experiments I came up to fact, that
>> breakpoints doesn't work in modules :(
>> I do the following:
>>
>> 1. boot up target with no modules loaded
>> 2. connect gdb-kgdblight to target
>> 3. in gdb I'm setting breakpoint:
>> ***
>> (kgdb) b ath_attach
>> Function "ath_attach" not defined.
>> Make breakpoint pending on future shared library load? (y or [n]) y
>> Breakpoint 1 (ath_attach) pending.
>> ***
>> 4. then I'm loading module on target:
>> ***
>> modprobe ath_pci
>> ***
>> and I see printk messages from ath_attach (this function is executed
>> on module load), breakpoint doen't work in this case.
>> 5. then in gdb I do following:
>> ***
>> (kgdb) d
>> Delete all breakpoints? (y or n) y
>> (kgdb) info shared
>> Reading symbols from /root/dev/objs/ath_pci.ko...expanding to full
>> symbols...done.
>> Loaded symbols for /root/dev/objs/ath_pci.ko
>> Reading symbols from /root/dev/objs/ath_rate_ctrl.ko...expanding to
>> full symbols...done.
>> Loaded symbols for /root/dev/objs/ath_rate_ctrl.ko
>> Reading symbols from /root/dev/objs/wlan.ko...expanding to full
>> symbols...done.
>> Loaded symbols for /root/dev/objs/wlan.ko
>> Reading symbols from /root/dev/objs/ath_dfs.ko...expanding to full
>> symbols...done.
>> Loaded symbols for /root/dev/objs/ath_dfs.ko
>> Reading symbols from /root/dev/objs/ath_hal.ko...expanding to full
>> symbols...done.
>> Loaded symbols for /root/dev/objs/ath_hal.ko
>> From To Syms Read Shared Object Library
>> 0xe0766000 0xe07660f4 Yes /root/dev/objs/pcspkr.ko
>> 0xe076b000 0xe076e714 Yes /root/dev/objs/e100.ko
>> 0xe13df000 0xe13ecec0 Yes /root/dev/objs/ath_pci.ko
>> 0xe1236000 0xe1237950 Yes /root/dev/objs/ath_rate_ctrl.ko
>> 0xe1024000 0xe103ea34 Yes /root/dev/objs/wlan.ko
>> 0xe0a17000 0xe0a1ab9c Yes /root/dev/objs/ath_dfs.ko
>> 0xe0934000 0xe0952968 Yes /root/dev/objs/ath_hal.ko
>> (kgdb) b ath_attach
>> Breakpoint 3 at 0xe13e8cb0: file /root/dev/madwifi-9999/ath/if_ath.c,
>> line 426.
>> ***
>> 6. then on target i do rmmod and modprobe again, and even in this case
>> I see printk messages from ath_attach so breakpoint didn't stop code
>> execution what is wrong.
>>
>> Regards,
>> Dmitry.
>>
>> Mithlesh Thukral wrote:
>>> These messages are coming because you turned enabled remote debugging
>>> by :
>>> "set debug remote 1"
>>>
>>> HTH,
>>> Mithlesh Thukral
>>
>>
>
>
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