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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 E692AC433DB for ; Tue, 2 Mar 2021 02:28:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AF41F6186A for ; Tue, 2 Mar 2021 02:28:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240577AbhCBBWW (ORCPT ); Mon, 1 Mar 2021 20:22:22 -0500 Received: from m42-2.mailgun.net ([69.72.42.2]:38250 "EHLO m42-2.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235274AbhCATGN (ORCPT ); Mon, 1 Mar 2021 14:06:13 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1614625552; h=Content-Transfer-Encoding: MIME-Version: References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=8dusOMR2FioRvirR8Z2x+dUBqtTvzGGg36FllLPNcGY=; b=EOpG8xwzRgo+rDpRt2N0ZTVPCGlVbCze5PlXHr6lSedIwnUpmWFl9GS+Zf6Pb2u6uyMjx85e lW48Qy8xGEsmLSuXVO9XTMAALv643vwNhunM8HpA75Zp5rd+yJvIyYDob+PUop823uBT8WhB rJ9ILfvyWBOpvYGqOoHDg7hNYrY= X-Mailgun-Sending-Ip: 69.72.42.2 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n07.prod.us-west-2.postgun.com with SMTP id 603d3ae61e1364c09d1b115d (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Mon, 01 Mar 2021 19:05:10 GMT Sender: saiprakash.ranjan=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 1B1FEC433C6; Mon, 1 Mar 2021 19:05:10 +0000 (UTC) Received: from blr-ubuntu-253.qualcomm.com (blr-bdr-fw-01_GlobalNAT_AllZones-Outside.qualcomm.com [103.229.18.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: saiprakash.ranjan) by smtp.codeaurora.org (Postfix) with ESMTPSA id B0C42C433CA; Mon, 1 Mar 2021 19:05:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org B0C42C433CA Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=saiprakash.ranjan@codeaurora.org From: Sai Prakash Ranjan To: Mathieu Poirier , Suzuki K Poulose , Mike Leach , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Leo Yan Cc: Jiri Olsa , Namhyung Kim , coresight@lists.linaro.org, Stephen Boyd , Denis Nikitin , Mattias Nissler , Al Grant , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Douglas Anderson , Sai Prakash Ranjan Subject: [PATCHv2 3/4] coresight: etm4x: Add support to exclude kernel mode tracing Date: Tue, 2 Mar 2021 00:34:17 +0530 Message-Id: X-Mailer: git-send-email 2.29.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On production systems with ETMs enabled, it is preferred to exclude kernel mode(NS EL1) tracing for security concerns and support only userspace(NS EL0) tracing. Perf subsystem interface uses the newly introduced kernel config CONFIG_EXCLUDE_KERNEL_PMU_TRACE to exclude kernel mode tracing, but there is an additional interface via sysfs for ETMs which also needs to be handled to exclude kernel mode tracing. So we use this same generic kernel config to handle the sysfs mode of tracing. This config is disabled by default and would not affect the current configuration which has both kernel and userspace tracing enabled by default. Tested-by: Denis Nikitin Signed-off-by: Sai Prakash Ranjan --- drivers/hwtracing/coresight/coresight-etm4x-core.c | 6 +++++- drivers/hwtracing/coresight/coresight-etm4x-sysfs.c | 6 ++++++ 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index 15016f757828..dbd6b96f3a78 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -1235,12 +1235,16 @@ static void etm4_set_default(struct etmv4_config *config) return; /* - * Make default initialisation trace everything + * Make default initialisation trace everything when + * CONFIG_EXCLUDE_KERNEL_PMU_TRACE is disabled. * * This is done by a minimum default config sufficient to enable * full instruction trace - with a default filter for trace all * achieved by having no filtering. */ + if (IS_ENABLED(CONFIG_EXCLUDE_KERNEL_PMU_TRACE)) + config->mode |= ETM_MODE_EXCL_KERN; + etm4_set_default_config(config); etm4_set_default_filter(config); } diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c index 0995a10790f4..78ba2a0888fc 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c @@ -296,6 +296,12 @@ static ssize_t mode_store(struct device *dev, if (kstrtoul(buf, 16, &val)) return -EINVAL; + if (IS_ENABLED(CONFIG_EXCLUDE_KERNEL_PMU_TRACE) && (!(val & ETM_MODE_EXCL_KERN))) { + dev_warn(dev, + "Kernel mode tracing is not allowed, check your kernel config\n"); + return -EACCES; + } + spin_lock(&drvdata->spinlock); config->mode = val & ETMv4_MODE_ALL; -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation