linux-kernel - Re: [-mm patch] ptrace: make {put,get}reg work again for gs and fs

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Message-ID: <20061222080539.GE18827@slug>
Date:	Fri, 22 Dec 2006 08:05:39 +0000
From:	Frederik Deweerdt <deweerdt@...e.fr>
To:	Andrew Morton <akpm@...l.org>
Cc:	Jeremy Fitzhardinge <jeremy@...p.org>, linux-kernel@...r.kernel.org
Subject: Re: [-mm patch] ptrace: make {put,get}reg work again for gs and fs

On Thu, Dec 21, 2006 at 10:54:14PM -0800, Andrew Morton wrote:
> On Fri, 22 Dec 2006 06:06:18 +0000
> Frederik Deweerdt <deweerdt@...e.fr> wrote:
> 
> > On Thu, Dec 21, 2006 at 06:11:08PM -0800, Andrew Morton wrote:
> > > On Thu, 21 Dec 2006 18:00:49 -0800
> > > Jeremy Fitzhardinge <jeremy@...p.org> wrote:
> > > 
> > > > Frederik Deweerdt wrote:
> > > > > This is a -mm1 kernel + your efl_offset fix + the attached patch.
> > > > > So the problem came from putreg still saving %gs to the stack where
> > > > > there's no slot for it, whereas getreg got things right.
> > > > >   
> > > > 
> > > > That patch looks good, but I think it is already effectively in Andrew's
> > > > queue, because I noticed some problems in there when I reviewed  the
> > > > convert-to-%fs patch.
> > > > 
> > > 
> > > The below is what I have queued for urgent mainlining to address these
> > > problems.
> > > 
> > > Is it sufficient?
> > > 
> > No, it's not. The patch below fixes the place where we get eflags, this
> > triggered the "BUG while gdb'ing" reports.
> > The one I sent was to fix a problem that only I reported, AFAIK: when
> > you use gdb/ptrace to modify %fs, the value gets written in the wrong
> > place (see gdb sessions). So, unless you have another patch fixing the
> > way putreg() writes %fs, the patch[1] I sent should also be queued for
> > mainline.
> 
> OK, but you're using -mm, yes?  And -mm has (the rather irritating)
> convert-i386-pda-code-to-use-%fs.patch in it.
> 
> So perhaps your fix is a -mm-only thing?
> 
It is sorry, I mixed things up. BTW, your mails don't seem to make it to
the lkml (see http://lkml.org/lkml/2006/12/22/10)

Regards,
Frederik
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