Jan Kiszka wrote:
> Hi,
> 
> the kgdb-over-ipipe add-on patches available from gna.org contain two
> bugs that prevents stepping through Xenomai kernel threads. The attached
> update fixes them. It also contains the workaround to build kgdb with
> gcc-3.4 (before 3.4.4) and 4.1 (before 4.1.2).
> 
> Tested on 2.6.17.13 with latest kgdb from CVS.
> 

It turned out (*) that kgdb over I-pipe only works reliably for
!CONFIG_PREEMPT (e.g. due to rcu_read_lock in the int3 notifier path).
Until some solution has been worked out, switch preemption off when you
use the debugger.

Jan


(*) Ever tried to debug a debugger? Here is one way to do this without
special hardware: Xenomai in qemu, one ddd attached to kgdb over
emulated serial port on /dev/pts/X, another ddd attached to qemu as
debugger back-end ("-s"). Sounds like fun? It isn't.