From patchwork Tue Oct 12 05:39:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?546L6LSH?= X-Patchwork-Id: 12551527 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 1DEE7C433FE for ; Tue, 12 Oct 2021 05:39:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EEF59610A3 for ; Tue, 12 Oct 2021 05:39:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230449AbhJLFlZ (ORCPT ); Tue, 12 Oct 2021 01:41:25 -0400 Received: from out30-130.freemail.mail.aliyun.com ([115.124.30.130]:33227 "EHLO out30-130.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229688AbhJLFlY (ORCPT ); Tue, 12 Oct 2021 01:41:24 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R861e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04400;MF=yun.wang@linux.alibaba.com;NM=1;PH=DS;RN=31;SR=0;TI=SMTPD_---0UrXmxxi_1634017156; Received: from testdeMacBook-Pro.local(mailfrom:yun.wang@linux.alibaba.com fp:SMTPD_---0UrXmxxi_1634017156) by smtp.aliyun-inc.com(127.0.0.1); Tue, 12 Oct 2021 13:39:18 +0800 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 Subject: [PATCH 0/2] ftrace: make sure preemption disabled on recursion testing Message-ID: <8c7de46d-9869-aa5e-2bb9-5dbc2eda395e@linux.alibaba.com> Date: Tue, 12 Oct 2021 13:39:16 +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 Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org 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. 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. 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(-) Acked-by: Palmer Dabbelt # RISC-V