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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 ED01DC43219 for ; Fri, 3 May 2019 16:04:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C1A362087F for ; Fri, 3 May 2019 16:04:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728435AbfECQEm (ORCPT ); Fri, 3 May 2019 12:04:42 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:36376 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725809AbfECQEm (ORCPT ); Fri, 3 May 2019 12:04:42 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B4582374; Fri, 3 May 2019 09:04:41 -0700 (PDT) Received: from en101.cambridge.arm.com (en101.cambridge.arm.com [10.1.196.93]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 998F33F557; Fri, 3 May 2019 09:04:40 -0700 (PDT) From: Suzuki K Poulose To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, coresight@lists.linaro.org, mathieu.poirier@linaro.org, Suzuki K Poulose Subject: [PATCH 2/2] coresight: alloc_perf_buf: Do not call smp_processor_id from preemptible Date: Fri, 3 May 2019 17:04:19 +0100 Message-Id: <1556899459-27785-2-git-send-email-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1556899459-27785-1-git-send-email-suzuki.poulose@arm.com> References: <1556899459-27785-1-git-send-email-suzuki.poulose@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We find the current CPU using smp_processor_id() if the event is not bound to a CPU, to find the node for memory allocation. Use the safe numa_node_id() instead to avoid BUG(). BUG: using smp_processor_id() in preemptible [00000000] code: perf/1743 caller is tmc_alloc_etr_buffer+0x1bc/0x1f0 CPU: 1 PID: 1743 Comm: perf Not tainted 5.1.0-rc6-147786-g116841e #344 Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Feb 1 2019 Call trace: dump_backtrace+0x0/0x150 show_stack+0x14/0x20 dump_stack+0x9c/0xc4 debug_smp_processor_id+0x10c/0x110 tmc_alloc_etr_buffer+0x1bc/0x1f0 etm_setup_aux+0x1c4/0x230 rb_alloc_aux+0x1b8/0x2b8 perf_mmap+0x35c/0x478 mmap_region+0x34c/0x4f0 do_mmap+0x2d8/0x418 vm_mmap_pgoff+0xd0/0xf8 ksys_mmap_pgoff+0x88/0xf8 __arm64_sys_mmap+0x28/0x38 el0_svc_handler+0xd8/0x138 el0_svc+0x8/0xc Fixes: 22f429f19c4135d51e9 ("coresight: etm-perf: Add support for ETR backend") Cc: Mathieu Poirier Signed-off-by: Suzuki K Poulose --- drivers/hwtracing/coresight/coresight-tmc-etr.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 74578bd..104df66 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1184,14 +1184,11 @@ static struct etr_buf * alloc_etr_buf(struct tmc_drvdata *drvdata, struct perf_event *event, int nr_pages, void **pages, bool snapshot) { - int node, cpu = event->cpu; + int node; struct etr_buf *etr_buf; unsigned long size; - if (cpu == -1) - cpu = smp_processor_id(); - node = cpu_to_node(cpu); - + node = (event->cpu == -1) ? numa_node_id() : cpu_to_node(event->cpu); /* * Try to match the perf ring buffer size if it is larger * than the size requested via sysfs. -- 2.7.4