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=-6.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_PASS autolearn=ham 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 C7870C43381 for ; Wed, 27 Feb 2019 23:20:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8AC07218AC for ; Wed, 27 Feb 2019 23:20:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730440AbfB0XUR (ORCPT ); Wed, 27 Feb 2019 18:20:17 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36064 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728397AbfB0XUQ (ORCPT ); Wed, 27 Feb 2019 18:20:16 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 75E4D30BADAC; Wed, 27 Feb 2019 23:20:16 +0000 (UTC) Received: from [10.10.121.150] (ovpn-121-150.rdu2.redhat.com [10.10.121.150]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AD8C4610A3; Wed, 27 Feb 2019 23:20:15 +0000 (UTC) Subject: Re: [PATCH] x86/stacktrace: export save_stack_trace_tsk_reliable From: Joe Lawrence To: Thomas Gleixner Cc: linux-kernel@vger.kernel.org, live-patching@vger.kernel.org, x86@kernel.org, Jiri Slaby , Josh Poimboeuf References: <20190227211748.9545-1-joe.lawrence@redhat.com> <07491738-dfdb-deb4-7e25-f1c173dda773@redhat.com> Message-ID: <873cd5ca-1f88-499e-e8ed-9a93f42d8239@redhat.com> Date: Wed, 27 Feb 2019 18:20:14 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.0 MIME-Version: 1.0 In-Reply-To: <07491738-dfdb-deb4-7e25-f1c173dda773@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Wed, 27 Feb 2019 23:20:16 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/27/19 5:25 PM, Joe Lawrence wrote: > On 2/27/19 4:31 PM, Thomas Gleixner wrote: >> On Wed, 27 Feb 2019, Joe Lawrence wrote: >> >>> The ppc64le implementation of save_stack_trace_tsk_reliable() is >>> exported, so do the same with x86. >> >> And what's the in tree module user of this? I can't find one and just >> because PPC has an export with no user is not a convincing argument to add >> another one. The proper solution is to remove the unused PPC export. >> > > Good point. > > For that matter, I do see in-tree modules making use of > save_stack_trace, but who is calling save_stack_trace_tsk (exported by > most arches) and save_stack_trace_regs (exported by openrisc, powerpc, > s390)? Well, at least for save_stack_trace_tsk there is the out-of-tree kpatch core module[1]. (Kpatch drops that call if the kernel provides livepatch functionality.) [1] https://github.com/dynup/kpatch/blob/master/kmod/core/core.c#L275 -- Joe