From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Fri, 29 Sep 2006 00:12:31 +0200
From: Jan Kiszka <jan.kiszka@domain.hid>
MIME-Version: 1.0
Subject: Re: [Xenomai-core] [PATCH] fix for kgbd patch
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Jan Kiszka wrote:
> Hi,
>=20
> the kgdb-over-ipipe add-on patches available from gna.org contain two
> bugs that prevents stepping through Xenomai kernel threads. The attache=
d
> 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).
>=20
> Tested on 2.6.17.13 with latest kgdb from CVS.
>=20

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.


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