From mboxrd@z Thu Jan  1 00:00:00 1970
From: James Cownie <jcownie@etnus.com>
To: gdb@sources.redhat.com
Subject: Re: gdb doesn't work very well with dynamic linked binaries
Date: Thu, 07 Sep 2000 01:55:00 -0000
Message-id: <200009070855.EAA00749@albacore>
X-SW-Source: 2000-09/msg00073.html

Mark Kettenis wrote :-
  I'm not sure whether the debug registers are
  per-thread or per-VM-space in Linux.  I'll probably need to look into
  the kernel source.

To save you the time, they are per-thread, just like all the 
other process' registers.

They are conceptually saved and restored on process scheduling
events (which for linuxthreads is the same thing as thread 
scheduling events, since linuxthreads _are_ processes as far as
the scheduler is concerned). 

The bug I mentioned previously is exactly that they're getting
cleared by the kernel and then not getting restored on return
to user space, leaving them wrong until the next reschedule :-(

-- 
-- Jim
James Cownie
jcownie@etnus.com
Etnus, Inc.
Phone +44 117 9071438