From mboxrd@z Thu Jan 1 00:00:00 1970 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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 8B1A4C282C4 for ; Mon, 4 Feb 2019 10:54:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 57BB12082F for ; Mon, 4 Feb 2019 10:54:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549277697; bh=CC0GoCvPlFMcJGrtlu1zr2ImShjUeFyVjFL+SIW6wLk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=QUWckIt/vvhXsPDVZ2gMU8LJeBbYJzCmS9mubJRxbqM455LxKxytdSNlZ0X7shkig HAJi1LqQz6a647DmHRjuEN97Q4ZOGDhYaasEaHA9kcympCD4hCH1ygXMVLJHDBphCB fbfCu827OQSy905YtwH6gJdPjXjwXuvY+mSco/f0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732900AbfBDKyM (ORCPT ); Mon, 4 Feb 2019 05:54:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:51992 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732897AbfBDKyM (ORCPT ); Mon, 4 Feb 2019 05:54:12 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F405B2082E; Mon, 4 Feb 2019 10:54:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549277651; bh=CC0GoCvPlFMcJGrtlu1zr2ImShjUeFyVjFL+SIW6wLk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hj5PPKa1KEmCZvXvKEcEdphA5JOQ2/GAatZMw6WnTnAvR2GUQwaiBab5573Ml90II +vWLKcxDaSFJvQhZdfV6tjPbjQ40f8MyB+XzMesBBo20MO9n19iaf5O+OvY3rMbjNK FDya7aN+rMb3UXfkNY+lN+uI9q38PMPKQts7MQII= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alan Tull , Frank Rowand , Guenter Roeck Subject: [PATCH 4.20 75/80] of: overlay: add tests to validate kfrees from overlay removal Date: Mon, 4 Feb 2019 11:37:35 +0100 Message-Id: <20190204103630.360941616@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190204103620.287366543@linuxfoundation.org> References: <20190204103620.287366543@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ From: Frank Rowand commit 144552c786925314c1e7cb8f91a71dae1aca8798 upstream. Add checks: - attempted kfree due to refcount reaching zero before overlay is removed - properties linked to an overlay node when the node is removed - node refcount > one during node removal in a changeset destroy, if the node was created by the changeset After applying this patch, several validation warnings will be reported from the devicetree unittest during boot due to pre-existing devicetree bugs. The warnings will be similar to: OF: ERROR: of_node_release(), unexpected properties in /testcase-data/overlay-node/test-bus/test-unittest11 OF: ERROR: memory leak, expected refcount 1 instead of 2, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node /testcase-data-2/substation@100/ hvac-medium-2 Tested-by: Alan Tull Signed-off-by: Frank Rowand Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- drivers/of/dynamic.c | 29 +++++++++++++++++++++++++++++ drivers/of/overlay.c | 1 + include/linux/of.h | 15 ++++++++++----- 3 files changed, 40 insertions(+), 5 deletions(-) --- a/drivers/of/dynamic.c +++ b/drivers/of/dynamic.c @@ -333,6 +333,25 @@ void of_node_release(struct kobject *kob if (!of_node_check_flag(node, OF_DYNAMIC)) return; + if (of_node_check_flag(node, OF_OVERLAY)) { + + if (!of_node_check_flag(node, OF_OVERLAY_FREE_CSET)) { + /* premature refcount of zero, do not free memory */ + pr_err("ERROR: memory leak before free overlay changeset, %pOF\n", + node); + return; + } + + /* + * If node->properties non-empty then properties were added + * to this node either by different overlay that has not + * yet been removed, or by a non-overlay mechanism. + */ + if (node->properties) + pr_err("ERROR: %s(), unexpected properties in %pOF\n", + __func__, node); + } + property_list_free(node->properties); property_list_free(node->deadprops); @@ -437,6 +456,16 @@ struct device_node *__of_node_dup(const static void __of_changeset_entry_destroy(struct of_changeset_entry *ce) { + if (ce->action == OF_RECONFIG_ATTACH_NODE && + of_node_check_flag(ce->np, OF_OVERLAY)) { + if (kref_read(&ce->np->kobj.kref) > 1) { + pr_err("ERROR: memory leak, expected refcount 1 instead of %d, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node %pOF\n", + kref_read(&ce->np->kobj.kref), ce->np); + } else { + of_node_set_flag(ce->np, OF_OVERLAY_FREE_CSET); + } + } + of_node_put(ce->np); list_del(&ce->node); kfree(ce); --- a/drivers/of/overlay.c +++ b/drivers/of/overlay.c @@ -373,6 +373,7 @@ static int add_changeset_node(struct ove return -ENOMEM; tchild->parent = target_node; + of_node_set_flag(tchild, OF_OVERLAY); ret = of_changeset_attach_node(&ovcs->cset, tchild); if (ret) --- a/include/linux/of.h +++ b/include/linux/of.h @@ -138,11 +138,16 @@ extern struct device_node *of_aliases; extern struct device_node *of_stdout; extern raw_spinlock_t devtree_lock; -/* flag descriptions (need to be visible even when !CONFIG_OF) */ -#define OF_DYNAMIC 1 /* node and properties were allocated via kmalloc */ -#define OF_DETACHED 2 /* node has been detached from the device tree */ -#define OF_POPULATED 3 /* device already created for the node */ -#define OF_POPULATED_BUS 4 /* of_platform_populate recursed to children of this node */ +/* + * struct device_node flag descriptions + * (need to be visible even when !CONFIG_OF) + */ +#define OF_DYNAMIC 1 /* (and properties) allocated via kmalloc */ +#define OF_DETACHED 2 /* detached from the device tree */ +#define OF_POPULATED 3 /* device already created */ +#define OF_POPULATED_BUS 4 /* platform bus created for children */ +#define OF_OVERLAY 5 /* allocated for an overlay */ +#define OF_OVERLAY_FREE_CSET 6 /* in overlay cset being freed */ #define OF_BAD_ADDR ((u64)-1)