Re: [ANNOUNCE] Merkey's Kernel Debugger

From: jmerkey
Date: Thu Aug 07 2008 - 15:55:55 EST


> Christoph Lameter wrote:
>> Stefan Richter wrote:
>>> Christoph Lameter wrote:
>>>> The competing implementation is kdb not kgdb. kgdb is just a stub for
>>>> remote
>>>> debugging using gdb. kdb is an in-kernel debugger like the one
>>>> proposed here.
>>> Is there work underway to get kdb merged? (I'm just asking because I
>>> don't know; I personally don't need kdb nor mdb.)
>>
>> KDB still exists in patches but the merge effort was given up when Linus
>> stated that he did not want a kernel debugger. No problem to start merge
>> attempts again AFAICT. Jay?
>
> To merge KDB or any other RAS tools, you need to deal with kdump. Kdump
> hijack panic() before the die calling chain. For KDB or a RAS tool to
> work, an infrastructure such as the "add new notifier function" by
> Takenori Nagano should be in place.
>
> His last attempt fell short, in my opinion, was partly due to his
> "[PATCH 3/3] Move crash_kexec() into panic_notifier" did not do what it
> meant to do: to fit kexec/kdump into the new infrastructure. That is
> not fatal; it can be fixed to make it right. If community is interested
> in getting a kernel debugger to the kernel, we can continue Takenori's
> work. Once the infrastructure is accepted, then merging KDB or any other
> kernel debugger will make sense.
>
> Regards,
> - jay
>
>
>>

As I look through entry_32.S and traps_32.c I do not see where kdump is
hooking the notify_die handler which would intercept calls to a debugger.

Where does kdump hook this path?

Jeff


>
>


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/