linux-mips
[Top] [All Lists]

Re: [PATCH 2/2] x86-64: seccomp: fix 32/64 syscall hole

To: Roland McGrath <roland@redhat.com>
Subject: Re: [PATCH 2/2] x86-64: seccomp: fix 32/64 syscall hole
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sat, 28 Feb 2009 09:23:36 -0800 (PST)
Cc: Andrew Morton <akpm@linux-foundation.org>, x86@kernel.org, linux-kernel@vger.kernel.org, stable@kernel.org, linux-mips@linux-mips.org, sparclinux@vger.kernel.org, linuxppc-dev@ozlabs.org
In-reply-to: <20090228072554.CFEA6FC3DA@magilla.sf.frob.com>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <20090228030226.C0D34FC3DA@magilla.sf.frob.com> <20090228030413.5B915FC3DA@magilla.sf.frob.com> <alpine.LFD.2.00.0902271932520.3111@localhost.localdomain> <alpine.LFD.2.00.0902271948570.3111@localhost.localdomain> <20090228072554.CFEA6FC3DA@magilla.sf.frob.com>
Sender: linux-mips-bounce@linux-mips.org
User-agent: Alpine 2.00 (LFD 1167 2008-08-23)

On Fri, 27 Feb 2009, Roland McGrath wrote:
> 
> I don't know any other arch well enough to be sure that TIF_32BIT isn't the
> wrong test there too.  I'd like to leave that worry to the arch maintainers.

Agreed - it may be that others will want to not use TIF_32BIT too. It 
really does make much more sense to have it as a thread-local status flag 
than as an atomic (and thus expensive to modify) thread-flag, not just on 
x86.

But I think other architectures will find it easier to see what's going on 
if the code is straightforward and they can just fix their 
'is_compat_task()' function. And:

> But here is the patch you asked for.

Yes, this looks much more straightforward. 

And I guess the seccomp interaction means that this is potentially a 
2.6.29 thing. Not that I know whether anybody actually _uses_ seccomp. It 
does seem to be enabled in at least Fedora kernels, but it might not be 
used anywhere.

                Linus

<Prev in Thread] Current Thread [Next in Thread>