Re: kgdb for mainline kernel: core-lite [patch 1/3]

[Andrew Morton <akpm@osdl.org>]

"Amit S. Kale" <amitkale@emsyssoft.com> wrote:
>
> > Let me just make sure we're taking about the same thing here.  Are you
> > saying that with kgdb-lite, `info threads' is completely missing, or does
> > it just not work correctly with threads (as opposed to heavyweight
> > processes)?
> 
> info threads shows a list of threads. Heavy/light weight processes doesn't 
> matter. Thread frame shown is incorrect.

It is?  I haven't noticed any problems with it here.  George recently
changed it to also display the process name in the gdb output, which is
valuable.

> I looked at i386 dependent code again. Following code in it is incorrect. I 
> never noticed it because this code is rarely used in full version of kgdb:
> 
> +void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct 
> *p)

There is no such function in the stub in -mm kernels.

> 
> Present threads support code changes calling convention of do_IRQ. Most 
> believe that to be an absolute no.

I see no such change in George's stub, unless I'm missing something again.

> Since you consider it a must-have, I'll check whether above changes suggested 
> by me make info threads listing correct in most cases.

The only problem I have with it is that sometimes after listing all threads
the debugger can lose control of the target and will start complaining
about communication errors.  I assume the target has died.  This happens
very rarely.  Usually when you're about to find the bug ;)