From patchwork Thu Dec 24 01:08:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Scally X-Patchwork-Id: 351966 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 ACD1FC4332E for ; Thu, 24 Dec 2020 01:10:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8EEAA22BF3 for ; Thu, 24 Dec 2020 01:10:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728663AbgLXBKK (ORCPT ); Wed, 23 Dec 2020 20:10:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48220 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728292AbgLXBKJ (ORCPT ); Wed, 23 Dec 2020 20:10:09 -0500 Received: from mail-wm1-x331.google.com (mail-wm1-x331.google.com [IPv6:2a00:1450:4864:20::331]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7DA03C061282; Wed, 23 Dec 2020 17:09:28 -0800 (PST) Received: by mail-wm1-x331.google.com with SMTP id a6so367993wmc.2; Wed, 23 Dec 2020 17:09:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=wLRZYS/XiFpA/R+VzuFliJ0iKwXJ0mePFvVmHUGHhWQ=; b=aKcyi/CgywK90dDzZFtZ/njuCWzotaIGtsSYSRuoHC+plDqIPX0WDn40fCdVK52yNH Kgg8YDTW+zOgrCpG28FLB2UdS8wa6K/v7VnkPInvmVrsX3gIMLV1FI8o3vG+wv8Ig7bJ RtyAFKMafLWmJaP48it1UYSS4zZIa83X4Phwnk2uFN1zh+lywKinGmnJvX2WSBUqUgwj 3mYzDSBlIjVs01apC7euovzWmbltt2X65BMUIbeERDh2j1PirWyz6L6D0ldMvj/eTTRY EOHjsR8vTSUh6B41lZBkqg+orZdKDFTbplSQX0gppOPnZ3Baxc9mdZqB3IjTxnoo0lu/ wtzg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=wLRZYS/XiFpA/R+VzuFliJ0iKwXJ0mePFvVmHUGHhWQ=; b=JdklmcNd0wGmh+pcNvDPwPZZMU8Gmnmdh4GNspnvjKIPWDRWa21P2GS3dM9jfnOxXS WcY8h3LAhA/uF3SG4zHSFWK41uPBPyQiqD1gSUYHWRqcERFc75k3ttLjB9K9RjjjK8c3 nFl3soXPPUO5IzHYizkChvA9N/jFcAD2R1d9pwGFumvQdhGrdybOoov0xonvnYPxTX/o dZb9xfT/IojodzjaPVHEYA8iJ/6ast4kgMgDFs7zXmi/23ytW1AX1gCRhVQNWnJFfHr5 vdXW6rAe5SwoqE6jntiYQNYFqYtr+Ux+FRgUlLOrKix40z5ksma9J5/Tl6Pz2EGIUlFr 48+g== X-Gm-Message-State: AOAM533UpplNIrH5C5LXX72M/2W07MU2YiABxSLLL9uXg9J7mOUpeCRi Cq055bJMWBLenE0U9oHSqKA8Xv6eVSjrV5Iv X-Google-Smtp-Source: ABdhPJx1zBodos95DtqoTr9JbuG6zQ6De8U6dLDJudQOFpHdRJ2p5ZuAkxs3B3U2ES5FDevopyB5Tw== X-Received: by 2002:a05:600c:218a:: with SMTP id e10mr1944501wme.27.1608772167161; Wed, 23 Dec 2020 17:09:27 -0800 (PST) Received: from valhalla.home ([2.31.224.116]) by smtp.gmail.com with ESMTPSA id b200sm1598653wmb.10.2020.12.23.17.09.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 23 Dec 2020 17:09:26 -0800 (PST) From: Daniel Scally To: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-media@vger.kernel.org, devel@acpica.org Cc: rjw@rjwysocki.net, lenb@kernel.org, gregkh@linuxfoundation.org, yong.zhi@intel.com, sakari.ailus@linux.intel.com, bingbu.cao@intel.com, tian.shu.qiu@intel.com, mchehab@kernel.org, robert.moore@intel.com, erik.kaneda@intel.com, pmladek@suse.com, rostedt@goodmis.org, sergey.senozhatsky@gmail.com, andriy.shevchenko@linux.intel.com, linux@rasmusvillemoes.dk, laurent.pinchart+renesas@ideasonboard.com, jacopo+renesas@jmondi.org, kieran.bingham+renesas@ideasonboard.com, hverkuil-cisco@xs4all.nl, m.felsch@pengutronix.de, niklas.soderlund+renesas@ragnatech.se, slongerbeam@gmail.com, heikki.krogerus@linux.intel.com, linus.walleij@linaro.org, Laurent Pinchart Subject: [PATCH v3 04/14] software_node: Enforce parent before child ordering of nodes arrays Date: Thu, 24 Dec 2020 01:08:57 +0000 Message-Id: <20201224010907.263125-5-djrscally@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201224010907.263125-1-djrscally@gmail.com> References: <20201224010907.263125-1-djrscally@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Registering software_nodes with the .parent member set to point to a currently unregistered software_node has the potential for problems, so enforce parent -> child ordering in arrays passed in to software_node_register_nodes(). Software nodes that are children of another software node should be unregistered before their parent. To allow easy unregistering of an array of software_nodes ordered parent to child, reverse the order in which software_node_unregister_nodes() unregisters software_nodes. Suggested-by: Andy Shevchenko Reviewed-by: Laurent Pinchart Signed-off-by: Daniel Scally --- Changes in v3 - kerneldoc comment cleanup drivers/base/swnode.c | 42 ++++++++++++++++++++++++++++++------------ 1 file changed, 30 insertions(+), 12 deletions(-) diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c index 615a0c93e116..ade49173ff8d 100644 --- a/drivers/base/swnode.c +++ b/drivers/base/swnode.c @@ -692,7 +692,11 @@ swnode_register(const struct software_node *node, struct swnode *parent, * software_node_register_nodes - Register an array of software nodes * @nodes: Zero terminated array of software nodes to be registered * - * Register multiple software nodes at once. + * Register multiple software nodes at once. If any node in the array + * has its .parent pointer set (which can only be to another software_node), + * then its parent **must** have been registered before it is; either outside + * of this function or by ordering the array such that parent comes before + * child. */ int software_node_register_nodes(const struct software_node *nodes) { @@ -700,14 +704,23 @@ int software_node_register_nodes(const struct software_node *nodes) int i; for (i = 0; nodes[i].name; i++) { - ret = software_node_register(&nodes[i]); - if (ret) { - software_node_unregister_nodes(nodes); - return ret; + const struct software_node *parent = nodes[i].parent; + + if (parent && !software_node_to_swnode(parent)) { + ret = -EINVAL; + goto err_unregister_nodes; } + + ret = software_node_register(&nodes[i]); + if (ret) + goto err_unregister_nodes; } return 0; + +err_unregister_nodes: + software_node_unregister_nodes(nodes); + return ret; } EXPORT_SYMBOL_GPL(software_node_register_nodes); @@ -715,18 +728,23 @@ EXPORT_SYMBOL_GPL(software_node_register_nodes); * software_node_unregister_nodes - Unregister an array of software nodes * @nodes: Zero terminated array of software nodes to be unregistered * - * Unregister multiple software nodes at once. + * Unregister multiple software nodes at once. If parent pointers are set up + * in any of the software nodes then the array **must** be ordered such that + * parents come before their children. * - * NOTE: Be careful using this call if the nodes had parent pointers set up in - * them before registering. If so, it is wiser to remove the nodes - * individually, in the correct order (child before parent) instead of relying - * on the sequential order of the list of nodes in the array. + * NOTE: If you are uncertain whether the array is ordered such that + * parents will be unregistered before their children, it is wiser to + * remove the nodes individually, in the correct order (child before + * parent). */ void software_node_unregister_nodes(const struct software_node *nodes) { - int i; + unsigned int i = 0; + + while (nodes[i].name) + i++; - for (i = 0; nodes[i].name; i++) + while (i--) software_node_unregister(&nodes[i]); } EXPORT_SYMBOL_GPL(software_node_unregister_nodes);