From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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,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 B5A6DC3A5A5 for ; Thu, 5 Sep 2019 13:42:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 408302070C for ; Thu, 5 Sep 2019 13:42:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730822AbfIENms (ORCPT ); Thu, 5 Sep 2019 09:42:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41426 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725975AbfIENms (ORCPT ); Thu, 5 Sep 2019 09:42:48 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4FAB9307D976; Thu, 5 Sep 2019 13:42:48 +0000 (UTC) Received: from treble (ovpn-120-170.rdu2.redhat.com [10.10.120.170]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AE3E75DAAC; Thu, 5 Sep 2019 13:42:41 +0000 (UTC) Date: Thu, 5 Sep 2019 08:42:39 -0500 From: Josh Poimboeuf To: Jiri Kosina Cc: Petr Mladek , Joe Lawrence , Miroslav Benes , linux-kernel@vger.kernel.org, live-patching@vger.kernel.org Subject: Re: [RFC PATCH 2/2] livepatch: Clear relocation targets on a module removal Message-ID: <20190905134239.fmoknq3z422tflst@treble> References: <20190826145449.wyo7avwpqyriem46@treble> <5c649320-a9bf-ae7f-5102-483bc34d219f@redhat.com> <20190904084932.gndrtewubqiaxmzy@pathway.suse.cz> <20190905025055.36loaatxtkhdo4q5@treble> <20190905110955.wl4lwjbnpqybhkcn@pathway.suse.cz> <20190905132344.byfybt6s42cajtfz@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Thu, 05 Sep 2019 13:42:48 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 05, 2019 at 03:31:56PM +0200, Jiri Kosina wrote: > On Thu, 5 Sep 2019, Josh Poimboeuf wrote: > > > > All the indirect jumps are turned into alternatives when retpolines > > > are in place. > > > > Actually in C code those are done by the compiler as calls/jumps to > > __x86_indirect_thunk_*. > > Sure, and the thunks do the redirection via JMP_NOSPEC / CALL_NOSPEC, > which has alternative in it. But the thunks are isolated to arch/x86/lib/retpoline.S. We can't patch that code anyway. -- Josh