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 11D51C282C3 for ; Tue, 22 Jan 2019 15:57:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DB04A217F9 for ; Tue, 22 Jan 2019 15:57:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729098AbfAVP5c (ORCPT ); Tue, 22 Jan 2019 10:57:32 -0500 Received: from mx1.redhat.com ([209.132.183.28]:53346 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728756AbfAVP5c (ORCPT ); Tue, 22 Jan 2019 10:57:32 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E837A87622; Tue, 22 Jan 2019 15:57:31 +0000 (UTC) Received: from jlaw-desktop.bos.redhat.com (dhcp-17-208.bos.redhat.com [10.18.17.208]) by smtp.corp.redhat.com (Postfix) with ESMTP id 932381019637; Tue, 22 Jan 2019 15:57:30 +0000 (UTC) From: Joe Lawrence To: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, live-patching@vger.kernel.org Cc: Balbir Singh , Jiri Kosina , Josh Poimboeuf , Michael Ellerman , Nicolai Stange , Torsten Duwe Subject: [PATCH 0/4] powerpc/livepatch: reliable stack unwinder fixes Date: Tue, 22 Jan 2019 10:57:20 -0500 Message-Id: <20190122155724.27557-1-joe.lawrence@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Tue, 22 Jan 2019 15:57:32 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 arch/powerpc/Kconfig | 2 +- arch/powerpc/kernel/entry_64.S | 7 +++ arch/powerpc/kernel/stacktrace.c | 74 +++++++++++++++++--------------- 3 files changed, 47 insertions(+), 36 deletions(-) -- 2.20.1