From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754595AbdASUWU (ORCPT ); Thu, 19 Jan 2017 15:22:20 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58320 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753872AbdASUWT (ORCPT ); Thu, 19 Jan 2017 15:22:19 -0500 Date: Thu, 19 Jan 2017 15:22:18 -0500 From: "Frank Ch. Eigler" To: Thomas Gleixner Cc: David Smith , Peter Zijlstra , Linus Torvalds , Andy Lutomirski , Ingo Molnar , "H. Peter Anvin" , "linux-kernel@vger.kernel.org" Subject: Re: [RFC][PATCH] x86: Verify access_ok() context Message-ID: <20170119202218.GB20931@redhat.com> References: <20161122095715.GN3092@twins.programming.kicks-ass.net> <20161122193720.GA3045@worktop.programming.kicks-ass.net> <20161205102747.GT3092@twins.programming.kicks-ass.net> <8758e5b4-050d-a5dd-2e58-e4f9dccc734b@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.2i X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Thu, 19 Jan 2017 20:22:20 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Thomas - On Thu, Jan 19, 2017 at 07:12:48PM +0100, Thomas Gleixner wrote: > [...] > It does matter very much, because the fact that the warning triggers tells > me that it's placed in code which is NOT executed in task context. > [...] > We are not papering over problems. Understood. We were interpreting the comments around access_ok to mean that the underlying hazard condition was different (stricter) than in_task(). If the warning could be made to match that hazard condition more precisely, then safe but non-in_task() callers can use access_ok() without the warning. - FChE