From patchwork Wed Jan 8 11:05:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suzuki K Poulose X-Patchwork-Id: 234235 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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 8F168C00523 for ; Wed, 8 Jan 2020 11:05:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5FC02206DA for ; Wed, 8 Jan 2020 11:05:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726281AbgAHLFq (ORCPT ); Wed, 8 Jan 2020 06:05:46 -0500 Received: from foss.arm.com ([217.140.110.172]:42374 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726276AbgAHLFq (ORCPT ); Wed, 8 Jan 2020 06:05:46 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0CD0B30E; Wed, 8 Jan 2020 03:05:46 -0800 (PST) Received: from ewhatever.cambridge.arm.com (ewhatever.cambridge.arm.com [10.1.197.1]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 0CCD53F703; Wed, 8 Jan 2020 03:05:44 -0800 (PST) From: Suzuki K Poulose To: stable@vger.kernel.org Cc: suzuki.poulose@arm.com, linux-arm-kernel@lists.infradead.org, mathieu.poirier@linaro.org, gregkh@linuxfoundation.org, Sasha Levin , linux-kernel@vger.kernel.org Subject: [stable] [PATCH 1/2] coresight: etb10: Do not call smp_processor_id from preemptible Date: Wed, 8 Jan 2020 11:05:40 +0000 Message-Id: <20200108110541.318672-1-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit 730766bae3280a25d40ea76a53dc6342e84e6513 ] During a perf session we try to allocate buffers on the "node" associated with the CPU the event is bound to. If it is not bound to a CPU, we use the current CPU node, using smp_processor_id(). However this is unsafe in a pre-emptible context and could generate the splats as below : BUG: using smp_processor_id() in preemptible [00000000] code: perf/2544 Use NUMA_NO_NODE hint instead of using the current node for events not bound to CPUs. Fixes: 2997aa4063d97fdb39 ("coresight: etb10: implementing AUX API") Cc: Mathieu Poirier Signed-off-by: Suzuki K Poulose Cc: stable # v4.9 to v4.19 Signed-off-by: Mathieu Poirier Link: https://lore.kernel.org/r/20190620221237.3536-5-mathieu.poirier@linaro.org --- drivers/hwtracing/coresight/coresight-etb10.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c index 0dad8626bcfb..6cf28b049635 100644 --- a/drivers/hwtracing/coresight/coresight-etb10.c +++ b/drivers/hwtracing/coresight/coresight-etb10.c @@ -275,9 +275,7 @@ static void *etb_alloc_buffer(struct coresight_device *csdev, int cpu, int node; struct cs_buffers *buf; - if (cpu == -1) - cpu = smp_processor_id(); - node = cpu_to_node(cpu); + node = (cpu == -1) ? NUMA_NO_NODE : cpu_to_node(cpu); buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node); if (!buf)