From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1754744AbbJ1AIt (ORCPT <rfc822;w@1wt.eu>);
	Tue, 27 Oct 2015 20:08:49 -0400
Received: from g2t4619.austin.hp.com ([15.73.212.82]:37791 "EHLO
	g2t4619.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1753385AbbJ1AIs (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Tue, 27 Oct 2015 20:08:48 -0400
Message-ID: <1445990693.20657.98.camel@hpe.com>
Subject: Re: [PATCH v2 0/4] x86: sigcontext fixes, again
From: Toshi Kani <toshi.kani@hpe.com>
To: Linus Torvalds <torvalds@linux-foundation.org>,
        Stas Sergeev <stsp@list.ru>, Andrew Morton <akpm@linux-foundation.org>,
        Toshi Kani <toshi.kani@hp.com>, Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>, Andy Lutomirski <luto@kernel.org>,
        X86 ML <x86@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Brian Gerst <brgerst@gmail.com>, Denys Vlasenko <dvlasenk@redhat.com>,
        Borislav Petkov <bp@alien8.de>,
        Stas Sergeev <stsp@users.sourceforge.net>
Date: Tue, 27 Oct 2015 18:04:53 -0600
In-Reply-To: <CA+55aFw9YAcNZDSStidcq8r-Fn7OqMMScrM6Pf=XOmBSC1aq2Q@mail.gmail.com>
References: <cover.1445822498.git.luto@kernel.org>
	 <562E126E.6030300@list.ru>
	 <CALCETrViit0LaXEcSOZHF99gdEbFDPGwLoO6q6aCfq2okToC7Q@mail.gmail.com>
	 <562F84AE.1030500@list.ru>
	 <CA+55aFw9YAcNZDSStidcq8r-Fn7OqMMScrM6Pf=XOmBSC1aq2Q@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
X-Mailer: Evolution 3.16.5 (3.16.5-3.fc22) 
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Wed, 2015-10-28 at 07:37 +0900, Linus Torvalds wrote:
> On Tue, Oct 27, 2015 at 11:05 PM, Stas Sergeev <stsp@list.ru> wrote:
> > 
> > I can't easily post an Oops: under X it doesn't even appear -
> > machine freezes immediately, and under non-KMS console it is
> > possible to get one, but difficult to screen-shot (using bare
> > metal, not VM). Also the Oops was seemingly unrelated.
> > And if you run "dosemu -s" under non-KMS console, you'll also
> > reproduce this one:
> > https://bugzilla.kernel.org/show_bug.cgi?id=97321
> 
> Hmm. Andrew Morton responded to that initially, but then nothing
> happened, and now it's been another six months. Andrew?
> 
> The arch/x86/mm/pat.c error handling does seem to be suspect. This is
> all code several years old, so none of this is new, and I think Suresh
> is gone.  Adding a few other people with recent sign-offs to that
> file, in the hope that somebody feels like they own it..

In the case of PFNMAP, the range should always be mapped.  So, I wonder why
follow_phys() failed with the !pte_present() check.

Stas, do you have a test program that can reproduce 97321?

-Toshi