From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=py8C=WU=vger.kernel.org=linux-kernel-owner@kernel.org>
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on
	aws-us-west-2-korg-lkml-1.web.codeaurora.org
X-Spam-Level: 
X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1
	autolearn=no autolearn_force=no version=3.4.0
Received: from mail.kernel.org (mail.kernel.org [198.145.29.99])
	by smtp.lore.kernel.org (Postfix) with ESMTP id 19E4BC3A5A2
	for <linux-kernel@archiver.kernel.org>; Sat, 24 Aug 2019 00:00:44 +0000 (UTC)
Received: from vger.kernel.org (vger.kernel.org [209.132.180.67])
	by mail.kernel.org (Postfix) with ESMTP id EDB8C206BA
	for <linux-kernel@archiver.kernel.org>; Sat, 24 Aug 2019 00:00:43 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1726370AbfHXAAn (ORCPT
        <rfc822;linux-kernel@archiver.kernel.org>);
        Fri, 23 Aug 2019 20:00:43 -0400
Received: from Galois.linutronix.de ([193.142.43.55]:36853 "EHLO
        Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1725857AbfHXAAm (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Fri, 23 Aug 2019 20:00:42 -0400
Received: from p5de0b6c5.dip0.t-ipconnect.de ([93.224.182.197] helo=nanos)
        by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256)
        (Exim 4.80)
        (envelope-from <tglx@linutronix.de>)
        id 1i1JTz-0002n5-Fw; Sat, 24 Aug 2019 02:00:39 +0200
Date:   Sat, 24 Aug 2019 02:00:38 +0200 (CEST)
From:   Thomas Gleixner <tglx@linutronix.de>
To:     Andy Lutomirski <luto@amacapital.net>
cc:     Sebastian Mayr <me@sam.st>, Ingo Molnar <mingo@redhat.com>,
        Borislav Petkov <bp@alien8.de>,
        "H. Peter Anvin" <hpa@zytor.com>, x86@kernel.org,
        LKML <linux-kernel@vger.kernel.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Andy Lutomirski <luto@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Dmitry Safonov <dsafonov@virtuozzo.com>,
        Oleg Nesterov <oleg@redhat.com>,
        Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Subject: Re: [PATCH] uprobes/x86: fix detection of 32-bit user mode
In-Reply-To: <32D5D6B1-B29E-426E-90B6-48565A3B8F3B@amacapital.net>
Message-ID: <alpine.DEB.2.21.1908240200070.1939@nanos.tec.linutronix.de>
References: <20190728152617.7308-1-me@sam.st> <alpine.DEB.2.21.1908232343470.1939@nanos.tec.linutronix.de> <alpine.DEB.2.21.1908240142000.1939@nanos.tec.linutronix.de> <32D5D6B1-B29E-426E-90B6-48565A3B8F3B@amacapital.net>
User-Agent: Alpine 2.21 (DEB 202 2017-01-01)
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="8323329-92855562-1566604839=:1939"
X-Linutronix-Spam-Score: -1.0
X-Linutronix-Spam-Level: -
X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required,  ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

  This message is in MIME format.  The first part should be readable text,
  while the remaining parts are likely unreadable without MIME-aware tools.

--8323329-92855562-1566604839=:1939
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8BIT

On Fri, 23 Aug 2019, Andy Lutomirski wrote:
> > On Aug 23, 2019, at 4:44 PM, Thomas Gleixner <tglx@linutronix.de> wrote:
> > 
> >> On Sat, 24 Aug 2019, Thomas Gleixner wrote:
> >>> On Sun, 28 Jul 2019, Sebastian Mayr wrote:
> >>> 
> >>> -static inline int sizeof_long(void)
> >>> +static inline int sizeof_long(struct pt_regs *regs)
> >>> {
> >>> -    return in_ia32_syscall() ? 4 : 8;
> >> 
> >>  This wants a comment.
> >> 
> >>> +    return user_64bit_mode(regs) ? 8 : 4;
> > 
> > The more simpler one liner is to check
> > 
> >    test_thread_flag(TIF_IA32)
> 
> I still want to finish killing TIF_IA32 some day.  Let’s please not add new users.

Well, yes and no. This needs to be backported ....
--8323329-92855562-1566604839=:1939--