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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1E0B4C433EF for ; Tue, 12 Oct 2021 06:04:02 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6488B60EE2 for ; Tue, 12 Oct 2021 06:04:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6488B60EE2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4HT4qN0W5rz3cML for ; Tue, 12 Oct 2021 17:04:00 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.alibaba.com (client-ip=115.124.30.132; helo=out30-132.freemail.mail.aliyun.com; envelope-from=yun.wang@linux.alibaba.com; receiver=) Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4HT4L23D86z2yPP for ; Tue, 12 Oct 2021 16:42:01 +1100 (AEDT) X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R351e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=e01e04423; MF=yun.wang@linux.alibaba.com; NM=1; PH=DS; RN=31; SR=0; TI=SMTPD_---0UrXyKWV_1634017303; Received: from testdeMacBook-Pro.local(mailfrom:yun.wang@linux.alibaba.com fp:SMTPD_---0UrXyKWV_1634017303) by smtp.aliyun-inc.com(127.0.0.1); Tue, 12 Oct 2021 13:41:45 +0800 Subject: Re: [PATCH 0/2] ftrace: make sure preemption disabled on recursion testing From: =?UTF-8?B?546L6LSH?= To: Guo Ren , Steven Rostedt , Ingo Molnar , "James E.J. Bottomley" , Helge Deller , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Paul Walmsley , Palmer Dabbelt , Albert Ou , Thomas Gleixner , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , Josh Poimboeuf , Jiri Kosina , Miroslav Benes , Petr Mladek , Joe Lawrence , Colin Ian King , Masami Hiramatsu , "Peter Zijlstra (Intel)" , Nicholas Piggin , Jisheng Zhang , linux-csky@vger.kernel.org, linux-kernel@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, live-patching@vger.kernel.org References: <8c7de46d-9869-aa5e-2bb9-5dbc2eda395e@linux.alibaba.com> Message-ID: Date: Tue, 12 Oct 2021 13:41:43 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: <8c7de46d-9869-aa5e-2bb9-5dbc2eda395e@linux.alibaba.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Mailman-Approved-At: Tue, 12 Oct 2021 17:02:48 +1100 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 2021/10/12 δΈ‹εˆ1:39, ηŽ‹θ΄‡ wrote: > The testing show that perf_ftrace_function_call() are using > smp_processor_id() with preemption enabled, all the checking > on CPU could be wrong after preemption, PATCH 1/2 will fix > that. 2/2 actually. > > Besides, as Peter point out, the testing of recursion within > the section between ftrace_test_recursion_trylock()/_unlock() > pair also need the preemption disabled as the documentation > explained, PATCH 2/2 will make sure on that. 1/2 actually... Regards, Michael Wang > > Michael Wang (2): > ftrace: disable preemption on the testing of recursion > ftrace: prevent preemption in perf_ftrace_function_call() > > arch/csky/kernel/probes/ftrace.c | 2 -- > arch/parisc/kernel/ftrace.c | 2 -- > arch/powerpc/kernel/kprobes-ftrace.c | 2 -- > arch/riscv/kernel/probes/ftrace.c | 2 -- > arch/x86/kernel/kprobes/ftrace.c | 2 -- > include/linux/trace_recursion.h | 10 +++++++++- > kernel/livepatch/patch.c | 6 ------ > kernel/trace/trace_event_perf.c | 17 +++++++++++++---- > kernel/trace/trace_functions.c | 5 ----- > 9 files changed, 22 insertions(+), 26 deletions(-) >