From: Paul Brook <paul@codesourcery.com>
To: qemu-devel@nongnu.org
Cc: "Stefan Hajnoczi" <stefanha@gmail.com>, 陳韋任 <chenwj@iis.sinica.edu.tw>
Subject: Re: [Qemu-devel] How to follow a child process created in the guest OS?
Date: Fri, 10 Feb 2012 23:48:05 +0000 [thread overview]
Message-ID: <201202102348.06492.paul@codesourcery.com> (raw)
In-Reply-To: <20120210102604.GA9791@cs.nctu.edu.tw>
> I am running this tiny OS on QEMU then using GDB to connect it.
>
> 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`.
You have exactly one CPU. That's what the qemu GDB stub exposes. Multiple
processes are an illusion created by your operating system. It is not
something qemu knows or cares about.
In most cases if you want to do debugging within that OS created illusion (aka
a userspace process) then you probably don't want to be using a hardware debug
probe (i.e. the qemu gdb stub) at all. Instead you want to be using the debug
facilities provided by your operating system. On linux this would be ptrace,
probably via gdbserver.
Paul
next prev parent reply other threads:[~2012-02-10 23:48 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-09 10:33 [Qemu-devel] How to follow a child process created in the guest OS? 陳韋任
2012-02-10 8:14 ` Stefan Hajnoczi
2012-02-10 10:26 ` 陳韋任
2012-02-10 23:48 ` Paul Brook [this message]
2012-02-10 23:54 ` 陳韋任
2012-02-11 0:42 ` Andreas Färber
2012-02-11 0:50 ` malc
2012-02-12 3:00 ` Wei Yang
2012-02-13 10:49 ` Stefan Hajnoczi
2012-02-10 9:24 ` Max Filippov
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