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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 37A8BC742BA for ; Fri, 12 Jul 2019 12:34:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0D18720645 for ; Fri, 12 Jul 2019 12:34:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562934895; bh=dwBSzYaJrmJSkrUYPKUiap1bMlzXZIw/v4IlMT1nhsg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=K4Tm9dDyDC0lDzpE7g6iJH1wvBisy28q+JSwvXkO1pEv/kVy9BjtV4+xmqyr0xnkk CXp5jiqCTQ4S4w3pJG9h0Us08hodUpJVzSJBahvgbxmavd3xcf5n81tg7kCRQX9+KO HZybCezwbMZo6NjZSTmFdjC4tIQfzJcy33VihGQA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729796AbfGLMex (ORCPT ); Fri, 12 Jul 2019 08:34:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:55048 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729798AbfGLMew (ORCPT ); Fri, 12 Jul 2019 08:34:52 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9031320645; Fri, 12 Jul 2019 12:34:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562934892; bh=dwBSzYaJrmJSkrUYPKUiap1bMlzXZIw/v4IlMT1nhsg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZhR0/xLEYRKap9GcJKidgV9bGKF/hH55W1vDl+4+Qb1RkxY8tmOQ92zcRGmTd70+f YppwjJFJLFh785bIvF1vRZwW4o3kGPch7fRqCcque/PrIMPSzHwPFZQakcAy7kwMy+ 76ngtmIk716VhwQN4qmcC7X+c1+ZPl4HjntErCDo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mathieu Poirier , Suzuki K Poulose Subject: [PATCH 5.2 48/61] coresight: tmc-etr: alloc_perf_buf: Do not call smp_processor_id from preemptible Date: Fri, 12 Jul 2019 14:20:01 +0200 Message-Id: <20190712121623.232838861@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190712121620.632595223@linuxfoundation.org> References: <20190712121620.632595223@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Suzuki K Poulose commit 3a8710392db2c70f74aed6f06b16e8bec0f05a35 upstream. 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/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 Use NUMA_NO_NODE hint instead of using the current node for events not bound to CPUs. Fixes: 22f429f19c4135d51e9 ("coresight: etm-perf: Add support for ETR backend") Cc: Mathieu Poirier Signed-off-by: Suzuki K Poulose Cc: stable # 4.20+ Signed-off-by: Mathieu Poirier Link: https://lore.kernel.org/r/20190620221237.3536-3-mathieu.poirier@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight-tmc-etr.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1178,14 +1178,11 @@ 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_NO_NODE : cpu_to_node(event->cpu); /* * Try to match the perf ring buffer size if it is larger * than the size requested via sysfs.