Re: [PATCH 1/3] KGDB: Major refactoring

From: Jason Wessel
Date: Wed Feb 06 2008 - 19:46:17 EST


Ingo Molnar wrote:
> * Jan Kiszka <jan.kiszka@xxxxxx> wrote:
>
>
>> As most changes are tightly coupled, this refactoring patch for
>> KGDB_8250 as well as the core and the new KGDBOC driver comes as a
>> single chunk. The changes are:
>> - Reorganized configuration: I/O drivers can be independently
>> configured as module or built-in
>> - Dynamic reconfiguration for KGDB_8250 (just like for KGDBOC)
>> - Reworked KGDB_8250 configuration string format
>> - attachwait removed, arming the debugger via assigning an I/O driver
>> implies "attachwait"
>> - Cleaned up I/O driver managment of the core
>> - Matured the various boot-up, configure, unconfigure code paths for
>> both I/O drivers
>> - IRQ vs. KGDB_CONSOLE-output SMP race fixed for KGDB_8250
>> - Reduced and cleaned up hooks into serial_core/8250
>> - Kconfig cleanups
>>
>
> great stuff! I've picked these cleanups up into x86.git. (will pick up
> Jason's commits too)
>
> Could you try something else too perhaps, which would be way useful for
> me: to add a sysctl flag (or something like that) to change kgdboc to
> accept a Ctrl-C and break into kgdb mode? [this means a simple Ctrl-C on
> a kgdboc line would break into KGDB as well - but that would be an
> acceptable price.] Right now kgdboc just hangs when gdb attaches - i
> have to generate a SysRq sequence via a terminal emulator to break it
> into KGDB mode.
>

FYI, even if you were to hack in a control-c vs sysrq, gdb will still
hang on connect because it does not issue a break of any kind when it
connects. It assumes the connection is in a usable state.

The proxy spliter automatically sends the break (or in the current case
the sysrq g)
> This would make kgdboc way more practical without having to resort to a
> protocol splitting proxy, etc.
>
> Ingo
>


Jason.
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