From patchwork Fri Jan 29 19:05:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sai Prakash Ranjan X-Patchwork-Id: 373411 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=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 3937CC433DB for ; Fri, 29 Jan 2021 19:09:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F309564E0E for ; Fri, 29 Jan 2021 19:09:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232654AbhA2TIP (ORCPT ); Fri, 29 Jan 2021 14:08:15 -0500 Received: from a1.mail.mailgun.net ([198.61.254.60]:31405 "EHLO a1.mail.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232976AbhA2TGt (ORCPT ); Fri, 29 Jan 2021 14:06:49 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1611947188; h=Content-Transfer-Encoding: MIME-Version: References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=VMujPUGd1jiuhd+wcY5Jmmw6odhxrHztTpfyjzjg/Dk=; b=BeIIEJP/GdJQDlr/O1Y1ijhpUBSM6GHH2j82OUtgTrixWRJcCbSvYQ+2paBCOrnW/7lTJOhO 3eSngqzwH5V7xk1ET+R70FDSdTpkzX3Kpf7kqUVr42PxrGmQ6sD4FsK/reKLcqU+aa6PKzoy 2TAPJW6KR/JBeFo4n2azoGvg5NM= X-Mailgun-Sending-Ip: 198.61.254.60 X-Mailgun-Sid: WyI1MzIzYiIsICJsaW51eC1hcm0tbXNtQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n01.prod.us-west-2.postgun.com with SMTP id 60145c926776573488be8bc7 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Fri, 29 Jan 2021 19:05:54 GMT Sender: saiprakash.ranjan=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 88302C4346D; Fri, 29 Jan 2021 19:05:54 +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 A92AEC433ED; Fri, 29 Jan 2021 19:05:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org A92AEC433ED 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 , Jiri Olsa , Namhyung Kim , Leo Yan Cc: 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, Sai Prakash Ranjan Subject: [PATCH 3/4] coresight: etm4x: Add support to exclude kernel mode tracing Date: Sat, 30 Jan 2021 00:35:12 +0530 Message-Id: <5d063d6035ff079b10e34cee110a26b856957ebe.1611909025.git.saiprakash.ranjan@codeaurora.org> X-Mailer: git-send-email 2.29.0 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@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 for ETMs use the newly introduced kernel config CONFIG_EXCLUDE_KERNEL_HW_ITRACE 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 | 14 +++++++++++++- .../hwtracing/coresight/coresight-etm4x-sysfs.c | 3 ++- 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index b20b6ff17cf6..f94143057bb8 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -1052,12 +1052,16 @@ static void etm4_set_default(struct etmv4_config *config) return; /* - * Make default initialisation trace everything + * Make default initialisation trace everything when + * CONFIG_EXCLUDE_KERNEL_HW_ITRACE 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_HW_ITRACE)) + config->mode |= ETM_MODE_EXCL_KERN; + etm4_set_default_config(config); etm4_set_default_filter(config); } @@ -1195,6 +1199,7 @@ static int etm4_set_event_filters(struct etmv4_drvdata *drvdata, void etm4_config_trace_mode(struct etmv4_config *config) { u32 mode; + struct etmv4_drvdata *drvdata = container_of(config, struct etmv4_drvdata, config); mode = config->mode; mode &= (ETM_MODE_EXCL_KERN | ETM_MODE_EXCL_USER); @@ -1202,6 +1207,13 @@ void etm4_config_trace_mode(struct etmv4_config *config) /* excluding kernel AND user space doesn't make sense */ WARN_ON_ONCE(mode == (ETM_MODE_EXCL_KERN | ETM_MODE_EXCL_USER)); + if (!(mode & ETM_MODE_EXCL_KERN) && IS_ENABLED(CONFIG_EXCLUDE_KERNEL_HW_ITRACE)) { + dev_err(&drvdata->csdev->dev, + "Kernel mode tracing is not allowed, check your kernel config\n"); + config->mode |= ETM_MODE_EXCL_KERN; + return; + } + /* nothing to do if neither flags are set */ if (!(mode & ETM_MODE_EXCL_KERN) && !(mode & ETM_MODE_EXCL_USER)) return; diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c index 989ce7b8ade7..f1d19d69d151 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c @@ -426,7 +426,8 @@ static ssize_t mode_store(struct device *dev, else config->vinst_ctrl &= ~BIT(11); - if (config->mode & (ETM_MODE_EXCL_KERN | ETM_MODE_EXCL_USER)) + if ((config->mode & (ETM_MODE_EXCL_KERN | ETM_MODE_EXCL_USER)) || + IS_ENABLED(CONFIG_EXCLUDE_KERNEL_HW_ITRACE)) etm4_config_trace_mode(config); spin_unlock(&drvdata->spinlock);