From patchwork Sun Jan 3 23:12:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Scally X-Patchwork-Id: 11996085 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=-15.8 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 8AF01C433E0 for ; Sun, 3 Jan 2021 23:15:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5EF0B207C9 for ; Sun, 3 Jan 2021 23:15:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727880AbhACXOQ (ORCPT ); Sun, 3 Jan 2021 18:14:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59474 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727807AbhACXOP (ORCPT ); Sun, 3 Jan 2021 18:14:15 -0500 Received: from mail-wm1-x329.google.com (mail-wm1-x329.google.com [IPv6:2a00:1450:4864:20::329]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BAEDAC061794; Sun, 3 Jan 2021 15:13:01 -0800 (PST) Received: by mail-wm1-x329.google.com with SMTP id v14so16482219wml.1; Sun, 03 Jan 2021 15:13:01 -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=t0IksVC5+HqVFsvTagMFtY4dHxSpSETaaDeLny9BEfw=; b=Y9aPVluz7ZiRNBE0VAq/PA+USLmHzlynN076j5LcQRt5Lmd950T4iLSq8q7RGOb0WQ SGtMCrav5wg2DuBdX8vozpqDfu9GRUuPw5o+n9xc6M+bveKCXWkllqcmupfAqzoUXJF+ yOWqz+6I5qVfAwCWO3yyQjiGVwmJnxjD5nuCBZHUiM+XkjDnMUq7TNmqOH4fa/pvmLaj QelOUZ7Fnw9vkjWuxOIMiyucsXqmw0MP22MCPPSmjG3hBZBcQTZrWTEqHjSKMuQ11KV9 RzJvZxTT4v7QP6S619vzTh3HCB2ZNPbpMFhj9q916VTc/J9SxV4THDgT1C2XLsyUmfPm veAQ== 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=t0IksVC5+HqVFsvTagMFtY4dHxSpSETaaDeLny9BEfw=; b=J8vRNCpF4+hmlV5EgxUAGdSy89+ag1SjFHbxTGrAaMYoJOev278PO+WePnyYB8xs7J wywdGd4Le63xO8cqUHhvhTz+vg7XVyw0sa6AsG3deBob0+q5D8jBNc6tXoBwD5aFg6US xdL2R6IlL9OWag0RuPH7eOPbUIQlfioe9KHjX0t5/qT2KZ5QcttVHgtpjXEcEbUZfZex XEKVLLQTBzApQigCn5WD+GsCM8XVAawiRk0TgW8/WynlPI1TC4h0AFxFmLpi4fg2TuBY Wnag6IZIb2qtMP9AwwBotmF/2YzluEh9fTHMZdEZfEIoetZ+ADYdwEAiZnza8PO8s36T OpMw== X-Gm-Message-State: AOAM531nNVFaY1EVDN+HvmIkK4J5FMVCzkUCreuiqGQKMS4bRC/3Mbo+ UMTiuFH/NvS2qWGlpFT2Gedsb3bUUdftr/Mm X-Google-Smtp-Source: ABdhPJyoQNwu5kDmlT2r51ee7jBxl5CzLzgqmIhb+UFbCKBPhrz74lukUIkXZ3OIv3ESgytELY0CUw== X-Received: by 2002:a1c:e084:: with SMTP id x126mr24298282wmg.109.1609715580503; Sun, 03 Jan 2021 15:13:00 -0800 (PST) Received: from valhalla.home ([2.29.208.120]) by smtp.gmail.com with ESMTPSA id h9sm32571018wme.11.2021.01.03.15.12.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 03 Jan 2021 15:13:00 -0800 (PST) From: Daniel Scally To: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-media@vger.kernel.org, devel@acpica.org, gregkh@linuxfoundation.org, rjw@rjwysocki.net, sergey.senozhatsky@gmail.com, mchehab@kernel.org Cc: lenb@kernel.org, yong.zhi@intel.com, sakari.ailus@linux.intel.com, bingbu.cao@intel.com, tian.shu.qiu@intel.com, robert.moore@intel.com, erik.kaneda@intel.com, pmladek@suse.com, rostedt@goodmis.org, 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 v4 05/15] software_node: Enforce parent before child ordering of nodes arrays Date: Sun, 3 Jan 2021 23:12:25 +0000 Message-Id: <20210103231235.792999-6-djrscally@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210103231235.792999-1-djrscally@gmail.com> References: <20210103231235.792999-1-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 v4: - None 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);