Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752301AbcD2SI0 (ORCPT ); Fri, 29 Apr 2016 14:08:26 -0400 Received: from mail-oi0-f48.google.com ([209.85.218.48]:36372 "EHLO mail-oi0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751615AbcD2SIY (ORCPT ); Fri, 29 Apr 2016 14:08:24 -0400 MIME-Version: 1.0 In-Reply-To: <6360fe5cab85aad424600518f645a9ac773cc72e.1461875890.git.jpoimboe@redhat.com> References: <6360fe5cab85aad424600518f645a9ac773cc72e.1461875890.git.jpoimboe@redhat.com> From: Andy Lutomirski Date: Fri, 29 Apr 2016 11:08:04 -0700 Message-ID: Subject: Re: [RFC PATCH v2 09/18] livepatch/x86: add TIF_PATCH_PENDING thread flag To: Josh Poimboeuf Cc: Jessica Yu , Jiri Kosina , Miroslav Benes , Ingo Molnar , Peter Zijlstra , Michael Ellerman , Heiko Carstens , live-patching@vger.kernel.org, "linux-kernel@vger.kernel.org" , X86 ML , linuxppc-dev@lists.ozlabs.org, "linux-s390@vger.kernel.org" , Vojtech Pavlik , Jiri Slaby , Petr Mladek , Chris J Arges , Andy Lutomirski Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 553 Lines: 14 On Thu, Apr 28, 2016 at 1:44 PM, Josh Poimboeuf wrote: > Add the TIF_PATCH_PENDING thread flag to enable the new livepatch > per-task consistency model for x86_64. The bit getting set indicates > the thread has a pending patch which needs to be applied when the thread > exits the kernel. > > The bit is placed in the least-significant word of the thread_info flags NAK to that part. The least-significant word thing is a huge hack that has gotten out of control. Please add the thing explicitly to all relevant masks. --Andy