From patchwork Sat Nov 21 03:01:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suman Anna X-Patchwork-Id: 330517 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 CF4E6C64E7A for ; Sat, 21 Nov 2020 03:02:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8446A22403 for ; Sat, 21 Nov 2020 03:02:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="Lqj+7k29" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727162AbgKUDCO (ORCPT ); Fri, 20 Nov 2020 22:02:14 -0500 Received: from fllv0016.ext.ti.com ([198.47.19.142]:50548 "EHLO fllv0016.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727244AbgKUDCL (ORCPT ); Fri, 20 Nov 2020 22:02:11 -0500 Received: from fllv0034.itg.ti.com ([10.64.40.246]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id 0AL323Ii047239; Fri, 20 Nov 2020 21:02:03 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1605927723; bh=HMdSdR7V2x6ONvh3fs4KsUST5GUzlhQZ7uiFijupU2c=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=Lqj+7k291l4uOnCc3kVwF8kQYBHb0BW5o8eF8kGAj9iRLYLA9cz/1vUohnuLBztDk +tviOeX/3dnyBSKwLsqhK6rmttpuzlfodLBoQdPnCM6UKKYlhCGssWYgYqfldg4y3S MEoKytFEBXH64ai8JApLvpaTOXndTo9ORGocMOs4= Received: from DLEE108.ent.ti.com (dlee108.ent.ti.com [157.170.170.38]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 0AL323oP021875 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 20 Nov 2020 21:02:03 -0600 Received: from DLEE102.ent.ti.com (157.170.170.32) by DLEE108.ent.ti.com (157.170.170.38) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3; Fri, 20 Nov 2020 21:02:02 -0600 Received: from lelv0327.itg.ti.com (10.180.67.183) by DLEE102.ent.ti.com (157.170.170.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3 via Frontend Transport; Fri, 20 Nov 2020 21:02:03 -0600 Received: from fllv0103.dal.design.ti.com (fllv0103.dal.design.ti.com [10.247.120.73]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id 0AL322tm006992; Fri, 20 Nov 2020 21:02:02 -0600 Received: from localhost ([10.250.68.46]) by fllv0103.dal.design.ti.com (8.14.7/8.14.7) with ESMTP id 0AL322mX038651; Fri, 20 Nov 2020 21:02:02 -0600 From: Suman Anna To: Bjorn Andersson , Mathieu Poirier CC: Arnaud Pouliquen , Loic Pallardy , Grzegorz Jaszczyk , Tony Lindgren , , , , Suman Anna Subject: [PATCH v2 2/3] remoteproc: Introduce deny_sysfs_ops flag Date: Fri, 20 Nov 2020 21:01:55 -0600 Message-ID: <20201121030156.22857-3-s-anna@ti.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201121030156.22857-1-s-anna@ti.com> References: <20201121030156.22857-1-s-anna@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org The remoteproc framework provides sysfs interfaces for changing the firmware name and for starting/stopping a remote processor through the sysfs files 'state' and 'firmware'. The 'recovery' sysfs file can also be used similarly to control the error recovery state machine of a remoteproc. These interfaces are currently allowed irrespective of how the remoteprocs were booted (like remoteproc self auto-boot, remoteproc client-driven boot etc). These interfaces can adversely affect a remoteproc and its clients especially when a remoteproc is being controlled by a remoteproc client driver(s). Also, not all remoteproc drivers may want to support the sysfs interfaces by default. Add support to deny the sysfs state/firmware/recovery change by introducing a state flag 'deny_sysfs_ops' that the individual remoteproc drivers can set based on their usage needs. The default behavior is to allow the sysfs operations as before. Signed-off-by: Suman Anna --- v2: revised to account for the 'recovery' sysfs file as well, patch description updated accordingly v1: https://patchwork.kernel.org/project/linux-remoteproc/patch/20180915003725.17549-5-s-anna@ti.com/ drivers/remoteproc/remoteproc_sysfs.c | 12 ++++++++++++ include/linux/remoteproc.h | 2 ++ 2 files changed, 14 insertions(+) diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c index bd2950a246c9..3fd18a71c188 100644 --- a/drivers/remoteproc/remoteproc_sysfs.c +++ b/drivers/remoteproc/remoteproc_sysfs.c @@ -49,6 +49,10 @@ static ssize_t recovery_store(struct device *dev, { struct rproc *rproc = to_rproc(dev); + /* restrict sysfs operations if not allowed by remoteproc drivers */ + if (rproc->deny_sysfs_ops) + return -EPERM; + if (sysfs_streq(buf, "enabled")) { /* change the flag and begin the recovery process if needed */ rproc->recovery_disabled = false; @@ -158,6 +162,10 @@ static ssize_t firmware_store(struct device *dev, char *p; int err, len = count; + /* restrict sysfs operations if not allowed by remoteproc drivers */ + if (rproc->deny_sysfs_ops) + return -EPERM; + err = mutex_lock_interruptible(&rproc->lock); if (err) { dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, err); @@ -225,6 +233,10 @@ static ssize_t state_store(struct device *dev, struct rproc *rproc = to_rproc(dev); int ret = 0; + /* restrict sysfs operations if not allowed by remoteproc drivers */ + if (rproc->deny_sysfs_ops) + return -EPERM; + if (sysfs_streq(buf, "start")) { if (rproc->state == RPROC_RUNNING) return -EBUSY; diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h index 3fa3ba6498e8..dbc3767f7d0e 100644 --- a/include/linux/remoteproc.h +++ b/include/linux/remoteproc.h @@ -508,6 +508,7 @@ struct rproc_dump_segment { * @has_iommu: flag to indicate if remote processor is behind an MMU * @auto_boot: flag to indicate if remote processor should be auto-started * @autonomous: true if an external entity has booted the remote processor + * @deny_sysfs_ops: flag to not permit sysfs operations on state, firmware and recovery * @dump_segments: list of segments in the firmware * @nb_vdev: number of vdev currently handled by rproc * @char_dev: character device of the rproc @@ -545,6 +546,7 @@ struct rproc { bool has_iommu; bool auto_boot; bool autonomous; + bool deny_sysfs_ops; struct list_head dump_segments; int nb_vdev; u8 elf_class;