Re: [RFC] [PATCH] In-kernel gdbstub based on utrace Infrastructure.

[Srikar Dronamraju <srikar@linux.vnet.ibm.com>]

> > 
> > I guess Christoph, Roland and Frank would be able to explain in a better
> > fashion the rational and advantages of this stub over convential gdb.
> 
> Hmm,. wouldn't it make much more sense to extend the current kgdb stub
> to include userspace debugging, providing an all-in-one solution?

I see two limitations but I guess there could be ways to get over it.
1. gdb requiring file that needs to be debugged. I always
thought it can either be a user program or a vmlinux file. gdb makes
most of the information(i.e registers) from the remote protocol to
display the backtrace, variable values and the like by reading this
file. 

2.  Also I am not sure if gdb has a way to tell the remote to switch the
context and provide information(registers) pertaining to the user mode/
kernel mode.

There could be other limitations too that I may not be aware.
> 
> I think it would be much more powerful to be able to observe the full
> software stack and not be limited by this user<->kernel barrier.
> 
> (Provided the user has sufficient privileges of course).

In this implementation, the current user can debug his/her own
processes. May be if we can debug both the context from same gdb then we
might have to place restrictions.. 

--
Thanks and Regards
Srikar
>