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[23.128.96.18]) by mx.google.com with ESMTP id e26si16247609edr.556.2021.03.03.11.18.59; Wed, 03 Mar 2021 11:19:42 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@mg.codeaurora.org header.s=smtp header.b=K+ccLQol; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238617AbhCBBU5 (ORCPT + 99 others); Mon, 1 Mar 2021 20:20:57 -0500 Received: from z11.mailgun.us ([104.130.96.11]:25468 "EHLO z11.mailgun.us" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240390AbhCATFw (ORCPT ); Mon, 1 Mar 2021 14:05:52 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1614625528; h=Content-Transfer-Encoding: MIME-Version: References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=Ba6OQaTorWDoty4vE97fErAm92Zsz5cMQKE02H+Mmlk=; b=K+ccLQol8RDL/ESvMzqK26gFg4a2yG5HSxlFjUhbevQ1W4VVswnECO8/CHngD4pjUX8uhM3E /kTUkAE+4qmgu6BNZASaIuh/tkNDjJ18PaV88GuiSa7n3ds1e7naVThOmPRvEU0yXJFV7Bco I5/aXA8XEfcZ9lT6561a9RPfhN4= X-Mailgun-Sending-Ip: 104.130.96.11 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-n05.prod.us-east-1.postgun.com with SMTP id 603d3aee1d4da3b75d0a4387 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Mon, 01 Mar 2021 19:05:18 GMT Sender: saiprakash.ranjan=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id C110CC433CA; Mon, 1 Mar 2021 19:05:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-caf-mail-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=ALL_TRUSTED,BAYES_00,SPF_FAIL autolearn=no autolearn_force=no version=3.4.0 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 6EC70C433C6; Mon, 1 Mar 2021 19:05:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 6EC70C433C6 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 4/4] coresight: etm3x: Add support to exclude kernel mode tracing Date: Tue, 2 Mar 2021 00:34:18 +0530 Message-Id: <0b165b2608eed1a61240539f4b812bd80b6ad1bd.1614624041.git.saiprakash.ranjan@codeaurora.org> 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. Signed-off-by: Sai Prakash Ranjan --- drivers/hwtracing/coresight/coresight-etm3x-core.c | 3 +++ drivers/hwtracing/coresight/coresight-etm3x-sysfs.c | 6 ++++++ 2 files changed, 9 insertions(+) diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c index cf64ce73a741..d94f6b01ca09 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c @@ -195,6 +195,9 @@ void etm_set_default(struct etm_config *config) if (WARN_ON_ONCE(!config)) return; + if (IS_ENABLED(CONFIG_EXCLUDE_KERNEL_PMU_TRACE)) + config->mode |= ETM_MODE_EXCL_KERN; + /* * Taken verbatim from the TRM: * diff --git a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c index e8c7649f123e..f522fc2e01b3 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c @@ -116,6 +116,12 @@ static ssize_t mode_store(struct device *dev, if (ret) return ret; + 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 & ETM_MODE_ALL; -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation