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,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 67247C2D0DB for ; Tue, 28 Jan 2020 14:25:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3CD4024681 for ; Tue, 28 Jan 2020 14:25:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580221543; bh=oy15risqczpxp08ZvCccyI4B4+/51RZGwN9W5BYJFnY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=EG5BJWymaXUXLD98RdZhptQ5gG6RloTt20faYUbASjv55+Pg26QIM6CrpVMCiw3An b7PnUIyqpr+AspTF6OEW9cP6H6l5QDnr7Ry5vNUeruJGOnOrK+4+SoXbJgxiH3fZmv AQPoyCtKw4UxNxr9169yp3ITcWylnw6yeDpNIqLA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733071AbgA1OZm (ORCPT ); Tue, 28 Jan 2020 09:25:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:52730 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733041AbgA1OZk (ORCPT ); Tue, 28 Jan 2020 09:25:40 -0500 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 DF4DB21739; Tue, 28 Jan 2020 14:25:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580221540; bh=oy15risqczpxp08ZvCccyI4B4+/51RZGwN9W5BYJFnY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1zdZL2gHKZ76p/OiAWqNB/hXC8DuKv6braQkTHsRsWJY+4uuxpHFGQPy2ZrxNGoRM EnJlByKddXIJffk8WjNwWbzV4g9ldGt6QF2JYOx/QodB3D4d7zeZOWa01hbX9uUFYw PwBJPHfK1OXOtbQsxzHreW7vmuJ0g6zT/Y2GYOl4= 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 4.9 264/271] coresight: tmc-etf: Do not call smp_processor_id from preemptible Date: Tue, 28 Jan 2020 15:06:53 +0100 Message-Id: <20200128135912.242546591@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200128135852.449088278@linuxfoundation.org> References: <20200128135852.449088278@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Suzuki K Poulose commit 024c1fd9dbcc1d8a847f1311f999d35783921b7f 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/2544 caller is tmc_alloc_etf_buffer+0x5c/0x60 CPU: 2 PID: 2544 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_etf_buffer+0x5c/0x60 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: 2e499bbc1a929ac ("coresight: tmc: implementing TMC-ETF AUX space API") Cc: Mathieu Poirier Signed-off-by: Suzuki K Poulose Cc: stable # 4.7+ Signed-off-by: Mathieu Poirier Link: https://lore.kernel.org/r/20190620221237.3536-4-mathieu.poirier@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight-tmc-etf.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c @@ -292,9 +292,7 @@ static void *tmc_alloc_etf_buffer(struct 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); /* Allocate memory structure for interaction with Perf */ buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);