Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753700AbcKCGc3 (ORCPT ); Thu, 3 Nov 2016 02:32:29 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:36597 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751492AbcKCGc1 (ORCPT ); Thu, 3 Nov 2016 02:32:27 -0400 Date: Thu, 3 Nov 2016 07:32:23 +0100 From: Ingo Molnar To: Linus Torvalds Cc: Tetsuo Handa , Peter Zijlstra , Ingo Molnar , Andrew Lutomirski , the arch/x86 maintainers , Linux Kernel Mailing List , Brian Gerst , Borislav Petkov , Jann Horn , Linux API , Kees Cook , Tycho Andersen Subject: Re: [4.9-rc3] BUG: unable to handle kernel paging request at ffffc900144dfc60 Message-ID: <20161103063223.GA3267@gmail.com> References: <201611012336.IAC18714.VLMOQSHOFtOFJF@I-love.SAKURA.ne.jp> <201611021950.FEJ34368.HFFJOOMLtQOVSF@I-love.SAKURA.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 759 Lines: 23 * Linus Torvalds wrote: > On Wed, Nov 2, 2016 at 4:50 AM, Tetsuo Handa > wrote: > >> > >> So I _think_ the fix is to just remove this. Perhaps something like > >> the attached? Adding scheduler people since this is in their code.. > > > > That is not sufficient, for another Oops occurs inside stack_not_used(). > > Since I don't want to break stack_not_used(), can we tolerate nested > > try_get_task_stack() usage and protect the whole sched_show_task()? > > Sure, looks good to me. > > But as Andy says, we should probably apply my patch too, just to get > rid of the useless hex printk and the ugly ifdeffery. Agreed, and I have applied both fixes to sched/urgent. Thanks, Ingo