From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753376AbcFTQeK (ORCPT ); Mon, 20 Jun 2016 12:34:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54093 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752006AbcFTQdy (ORCPT ); Mon, 20 Jun 2016 12:33:54 -0400 Date: Mon, 20 Jun 2016 17:31:11 +0200 From: Oleg Nesterov To: Andy Lutomirski Cc: Andy Lutomirski , X86 ML , "linux-kernel@vger.kernel.org" , Kees Cook , Borislav Petkov Subject: Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in ptrace Message-ID: <20160620153110.GB28057@redhat.com> References: <94bda8cd5f326ae5591c80fb5d7c1c22624accec.1466244711.git.luto@kernel.org> <20160619211906.GA14712@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Mon, 20 Jun 2016 16:33:54 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/19, Andy Lutomirski wrote: > > On Sun, Jun 19, 2016 at 2:19 PM, Oleg Nesterov wrote: > > > > And this leads to another question, why do we actually need to set/clear > > TS_COMPAT in set_personality_ia32() ?? > > Something's clearly buggy there, considering that > set_personality_64bit() does *not* clear it. Yes, yes, I too noticed this, and this doesn't match the "if (x32)" branch in set_personality_ia32(). But I think we do not really need to clear this bit. And probably set_personality_ia32() doesn't need to play with TS_COMPAT. Oleg.