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Date: Sat, 11 Feb 2012 07:54:42 +0800
From: =?utf-8?B?6Zmz6Z+L5Lu7?= <chenwj@iis.sinica.edu.tw>
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Subject: Re: [Qemu-devel] How to follow a child process created in the guest
 OS?
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To: Paul Brook <paul@codesourcery.com>
Cc: qemu-devel@nongnu.org

On Fri, Feb 10, 2012 at 11:48:05PM +0000, Paul Brook wrote:
> >   I am running this tiny OS on QEMU then using GDB to connect it.
> >=20
> > I want to follow task 1 after the forking, but it seems that GDB
> > stick with task 0 and cannot follow task 1 even I do `set follow-fork=
-mode
> > child`.
>=20
> You have exactly one CPU. That's what the qemu GDB stub exposes.  Multi=
ple=20
> processes are an illusion created by your operating system.  It is not=20
> something qemu knows or cares about.
>=20
> In most cases if you want to do debugging within that OS created illusi=
on (aka=20
> a userspace process) then you probably don't want to be using a hardwar=
e debug=20
> probe (i.e. the qemu gdb stub) at all. Instead you want to be using the=
 debug=20
> facilities provided by your operating system.  On linux this would be p=
trace,=20
> probably via gdbserver.

  I see. Thanks.

Regards,
chenwj

--=20
Wei-Ren Chen (=E9=99=B3=E9=9F=8B=E4=BB=BB)
Computer Systems Lab, Institute of Information Science,
Academia Sinica, Taiwan (R.O.C.)
Tel:886-2-2788-3799 #1667
Homepage: http://people.cs.nctu.edu.tw/~chenwj