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=-8.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 B2AF8C43441 for ; Fri, 9 Nov 2018 06:07:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 715702089A for ; Fri, 9 Nov 2018 06:07:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="obSE5JEN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 715702089A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727822AbeKIPqr (ORCPT ); Fri, 9 Nov 2018 10:46:47 -0500 Received: from mail-pl1-f196.google.com ([209.85.214.196]:40441 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727485AbeKIPqq (ORCPT ); Fri, 9 Nov 2018 10:46:46 -0500 Received: by mail-pl1-f196.google.com with SMTP id q19-v6so446640pll.7; Thu, 08 Nov 2018 22:07:46 -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; bh=l5ozhvvWzyBZj5k6LPtNqGH+J//xUcwxsT/zIZkxQ34=; b=obSE5JENCbWtFID5myPmb3gngun8kkHApC5voypc3FLHUtHFxDQ7SVFv6IoZTDX+DM 8nsvPrCIt/gTNs4vLWRx+0Ke8qlUaHfnZkhaeCeoRyGHBqVdkIOmdMUuvDTL5h9+DY+b Wo5Vsut8dz8gkWUECjFEKocLWNAGqMxX+f2cMjX4HdiRp0BlP585ZAGxe4YXJu25POam QnT8b9aZo62tHQLdNAFuCv1lEEd/9f4czgXlD9/0zGnGvM3cTMen1Xed1Y1VAX1QslyZ UmkCgvsWRy3hY2qh983pXQS6k6OaQEanYR4mzpqoZsPmDp3ViT2pBGsUJgR7uVDSmZpI UnAw== 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; bh=l5ozhvvWzyBZj5k6LPtNqGH+J//xUcwxsT/zIZkxQ34=; b=R3hTVxLSoFsBgW6dxEQ21o07nnXKVU05ypJMDQHGdoFfsdwH9q+7eLAXhGSeuoQhE3 kjKoeMsJui2UesLx2KG3FzZ3w1MAuUKU/seCHru7mQak+uUrZ44Sg/VgCl61sgGZPZ5H SVRTd0ZU4D6cxeOsL4ClvZ+fm7dxnfAaM6yQb+0kz2FVLrea5Ew5TwsVMUG+mycs+1sM UrxrnsZt6Ma5f672SnkBX06/zbwQ+8J59EgZtOXfPTjbK4guDwYRFoLR5HUwJKWE1cAt TcvaZACUP4LejgkWVxvLrEVFlMOpcXDOWo+4NcTQXyBrebl9fNYXDJf94wto9e9OF+tz Xq6A== X-Gm-Message-State: AGRZ1gKmOhqqnwHKmYdtW6XwnRnqDgAtfqSe8Cl+YTwWuHkmYNNgtriB aLdbruoMP3nhNBpTwYTEtrY= X-Google-Smtp-Source: AJdET5c+zkphJnGo8gmz6T2aoEJBOSOaFnCBjhRw43wZ44XMm1hiEaVTY9xjxmhahYJieUv+/fAuTw== X-Received: by 2002:a17:902:e10f:: with SMTP id cc15-v6mr7809574plb.309.1541743665663; Thu, 08 Nov 2018 22:07:45 -0800 (PST) Received: from localhost.localdomain (c-24-6-192-50.hsd1.ca.comcast.net. [24.6.192.50]) by smtp.gmail.com with ESMTPSA id c70-v6sm6620722pfg.97.2018.11.08.22.07.44 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 08 Nov 2018 22:07:45 -0800 (PST) From: frowand.list@gmail.com To: Rob Herring , Pantelis Antoniou , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Alan Tull , Moritz Fischer Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, devicetree@vger.kernel.org, linux-fpga@vger.kernel.org Subject: [PATCH v7 01/17] of: overlay: add tests to validate kfrees from overlay removal Date: Thu, 8 Nov 2018 22:05:49 -0800 Message-Id: <1541743565-23163-2-git-send-email-frowand.list@gmail.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1541743565-23163-1-git-send-email-frowand.list@gmail.com> References: <1541743565-23163-1-git-send-email-frowand.list@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Frank Rowand 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 --- drivers/of/dynamic.c | 29 +++++++++++++++++++++++++++++ drivers/of/overlay.c | 1 + include/linux/of.h | 15 ++++++++++----- 3 files changed, 40 insertions(+), 5 deletions(-) diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c index f4f8ed9b5454..12c3f9a15e94 100644 --- a/drivers/of/dynamic.c +++ b/drivers/of/dynamic.c @@ -330,6 +330,25 @@ void of_node_release(struct kobject *kobj) 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); @@ -434,6 +453,16 @@ struct device_node *__of_node_dup(const struct device_node *np, 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); diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c index 42b1f73ac5f6..f5fc8859a7ee 100644 --- a/drivers/of/overlay.c +++ b/drivers/of/overlay.c @@ -373,6 +373,7 @@ static int add_changeset_node(struct overlay_changeset *ovcs, return -ENOMEM; tchild->parent = target_node; + of_node_set_flag(tchild, OF_OVERLAY); ret = of_changeset_attach_node(&ovcs->cset, tchild); if (ret) diff --git a/include/linux/of.h b/include/linux/of.h index a5aee3c438ad..664cd5573ae2 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -138,11 +138,16 @@ static inline void of_node_put(struct device_node *node) { } 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) -- Frank Rowand