From patchwork Wed Feb 9 09:03:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Puranjay Mohan X-Patchwork-Id: 12740199 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B953C433EF for ; Wed, 9 Feb 2022 12:14:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229683AbiBIMN5 (ORCPT ); Wed, 9 Feb 2022 07:13:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232841AbiBIMNp (ORCPT ); Wed, 9 Feb 2022 07:13:45 -0500 Received: from lelv0142.ext.ti.com (lelv0142.ext.ti.com [198.47.23.249]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 850D5E01A22A; Wed, 9 Feb 2022 03:58:30 -0800 (PST) Received: from fllv0034.itg.ti.com ([10.64.40.246]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 21996C76083007; Wed, 9 Feb 2022 03:06:12 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1644397572; bh=Fn0tXBQRpBz/aFWd0LHh4mdtpypyY2LI48sKNyRaWbs=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=LgumQn26hUfrJRqhpE74LR89hwQXUutNLELMIwHTpgtIAQJPE65MZF8coAZy4Fybz 685grtGdv/LvWxwSA19Bi/OUrcEEDZOMoEPkpaOFfBaSX1UZs/Po2/Z3fQROoVTO+n MP0qsxbJYl3k+H2Rcx4dqex6FMB4O1f212+D6Hvs= Received: from DFLE109.ent.ti.com (dfle109.ent.ti.com [10.64.6.30]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 21996CjP045827 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 9 Feb 2022 03:06:12 -0600 Received: from DFLE105.ent.ti.com (10.64.6.26) by DFLE109.ent.ti.com (10.64.6.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.14; Wed, 9 Feb 2022 03:06:12 -0600 Received: from lelv0327.itg.ti.com (10.180.67.183) by DFLE105.ent.ti.com (10.64.6.26) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.14 via Frontend Transport; Wed, 9 Feb 2022 03:06:12 -0600 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id 21996A0b040498; Wed, 9 Feb 2022 03:06:11 -0600 From: Puranjay Mohan To: , , , , , , , , CC: Puranjay Mohan Subject: [PATCH v4 1/2] remoteproc: Introduce deny_sysfs_ops flag Date: Wed, 9 Feb 2022 14:33:41 +0530 Message-ID: <20220209090342.13220-2-p-mohan@ti.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220209090342.13220-1-p-mohan@ti.com> References: <20220209090342.13220-1-p-mohan@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: linux-remoteproc@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. Implement attribute_group->is_visible() to hide the sysfs state/firmware/recovery entries when deny_sysfs_ops flag is set. Signed-off-by: Puranjay Mohan Reviewed-by: Mathieu Poirier --- Changes in v3->v4: Use mode = 0444 in rproc_is_visible() to make the sysfs entries read-only when the deny_sysfs_ops flag is set. --- drivers/remoteproc/remoteproc_sysfs.c | 18 +++++++++++++++++- include/linux/remoteproc.h | 2 ++ 2 files changed, 19 insertions(+), 1 deletion(-) diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c index ea8b89f97d7b..da2d0eecfa44 100644 --- a/drivers/remoteproc/remoteproc_sysfs.c +++ b/drivers/remoteproc/remoteproc_sysfs.c @@ -230,6 +230,21 @@ static ssize_t name_show(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_RO(name); +static umode_t rproc_is_visible(struct kobject *kobj, struct attribute *attr, + int n) +{ + struct device *dev = kobj_to_dev(kobj); + struct rproc *rproc = to_rproc(dev); + umode_t mode = attr->mode; + + if (rproc->deny_sysfs_ops && (attr == &dev_attr_recovery.attr || + attr == &dev_attr_firmware.attr || + attr == &dev_attr_state.attr)) + mode = 0444; + + return mode; +} + static struct attribute *rproc_attrs[] = { &dev_attr_coredump.attr, &dev_attr_recovery.attr, @@ -240,7 +255,8 @@ static struct attribute *rproc_attrs[] = { }; static const struct attribute_group rproc_devgroup = { - .attrs = rproc_attrs + .attrs = rproc_attrs, + .is_visible = rproc_is_visible, }; static const struct attribute_group *rproc_devgroups[] = { diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h index e0600e1e5c17..3849c66ce38f 100644 --- a/include/linux/remoteproc.h +++ b/include/linux/remoteproc.h @@ -523,6 +523,7 @@ struct rproc_dump_segment { * @table_sz: size of @cached_table * @has_iommu: flag to indicate if remote processor is behind an MMU * @auto_boot: flag to indicate if remote processor should be auto-started + * @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 * @elf_class: firmware ELF class @@ -562,6 +563,7 @@ struct rproc { size_t table_sz; bool has_iommu; bool auto_boot; + bool deny_sysfs_ops; struct list_head dump_segments; int nb_vdev; u8 elf_class;