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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 C4E9DC282D7 for ; Wed, 30 Jan 2019 12:22:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9F43520882 for ; Wed, 30 Jan 2019 12:22:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728285AbfA3MW1 (ORCPT ); Wed, 30 Jan 2019 07:22:27 -0500 Received: from ozlabs.org ([203.11.71.1]:57287 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725768AbfA3MW0 (ORCPT ); Wed, 30 Jan 2019 07:22:26 -0500 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPSA id 43qMv31SbXz9s9h; Wed, 30 Jan 2019 23:22:23 +1100 (AEDT) From: Michael Ellerman To: Jiri Kosina , Joe Lawrence Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, live-patching@vger.kernel.org, Balbir Singh , Josh Poimboeuf , Nicolai Stange , Torsten Duwe Subject: Re: [PATCH 0/4] powerpc/livepatch: reliable stack unwinder fixes In-Reply-To: References: <20190122155724.27557-1-joe.lawrence@redhat.com> Date: Wed, 30 Jan 2019 23:22:22 +1100 Message-ID: <87y372pc75.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jiri Kosina writes: > On Tue, 22 Jan 2019, Joe Lawrence wrote: > >> This patchset fixes a false negative report (ie, unreliable) from the >> ppc64 reliable stack unwinder, discussed here [1] when it may >> inadvertently trip over a stale exception marker left on the stack. >> >> The first two patches fix this bug. Nicolai's change clears the marker >> from the stack when an exception is finished. The next patch modifies >> the unwinder to only look for such on stack elements when the ABI >> guarantees that they will actually be initialized. >> >> The final two patches consist of code cleanups that Nicolai and I >> spotted during the development of the fixes. >> >> Testing included re-running the original test scenario (loading a >> livepatch module on ppc64le) on a 5.0.0-rc2 kernel as well as a RHEL-7 >> backport. I ran internal tests on the RHEL-7 backport and no new test >> failures were introduced. I believe that Nicolai has done the same >> with respect to the first patch. >> >> [1] https://lore.kernel.org/lkml/7f468285-b149-37e2-e782-c9e538b997a9@redhat.com/ >> >> Joe Lawrence (3): >> powerpc/livepatch: relax reliable stack tracer checks for first-frame >> powerpc/livepatch: small cleanups in save_stack_trace_tsk_reliable() >> powerpc/livepatch: return -ERRNO values in >> save_stack_trace_tsk_reliable() >> >> Nicolai Stange (1): >> powerpc/64s: Clear on-stack exception marker upon exception return > > Michael, are you fine with this going through LP tree, or do you plan to > take it through yours? I'm happy to take it, unless there's some reason you'd rather it go via the LP tree? I don't have any automated live patch tests, but I assume if it's in linux-next someone can test it? :) cheers