Re: [patch] Fix attaching to Linux stopped processes

[Daniel Jacobowitz <drow@false.org>]

On Mon, Sep 18, 2006 at 11:53:31AM +0200, Jan Kratochvil wrote:
> > Is this new in kernel.org?  Or is it a Red Hat kernel patch?  Where
> > did it come from?
> 
> Thanks for checking it.
> OK, the patch was originally for GDB on Red Hat "kernel-2.6.17-1.2647.fc6".
> 
> Still it is reproducible even on both linux-2.6.17.13 and linux-2.6.18-rc4, you
> just need to "kill -CONT $pid" the inferior as gdb(1) will hang during
> attaching to it.  Screenshot (sorry for graphics):
> 	http://www.jankratochvil.net/priv/gdb.png

Oh right - I've seen this crash before.

> Also the patch looks right to me - after `PT_ATTACH' it is appropriate that
> `WSTOPSIG (status)' will report the original signal that stopped process,
> (WSTOPSIG (status) == SIGSTOP) <=> (process was in running/sleeping mode).

The part I was dubious about was the zero if already stopped by
sigstop.  In any case, I agree.  The patch to linux-nat.c is OK
to apply.

I'm not sure about the testcase though :-(  I don't think it'll work
without the RH patched kernel, will it?

-- 
Daniel Jacobowitz
CodeSourcery