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=-11.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 04C72C433DF for ; Thu, 21 May 2020 09:01:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D020320738 for ; Thu, 21 May 2020 09:01:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590051701; bh=w3fxajhFTGvFDzTWBK4lEmPVYCc520Ea48JTTVi5wf4=; h=Subject:To:From:Date:List-ID:From; b=nChFK5as3At2qns8rwpqtOgLSaHDnYGdD+jfc7yGWi9YKvLOI5hOC75U9zR0RrBM+ CWIGy72DudkMaJIwI5LRUmbHP77IAUaQ3hUxh2lDBrJ/OySPq6MiIfAMHVWe5e8DAm s9UCVsFGI5kw3OtpT/XLx4Hf53BUUUBIAOYLNgVM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728588AbgEUJBl (ORCPT ); Thu, 21 May 2020 05:01:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:45398 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728560AbgEUJBl (ORCPT ); Thu, 21 May 2020 05:01:41 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.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 EDC0320721; Thu, 21 May 2020 09:01:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590051700; bh=w3fxajhFTGvFDzTWBK4lEmPVYCc520Ea48JTTVi5wf4=; h=Subject:To:From:Date:From; b=ivy4mouSX+XhTAy3O6fIAAtyOq8NyRQMjCh7Kd3QJx5LgaxJ1yd6lMSGyz2p30kMF 63ypPVXp9FTPrpvRt4l9vNNwFhYEvRhrNO+kqbveMe+jFHVKulSY5ehb1xpmnFV6/y Ooxe6E5v+gMw7cGfBDJPjBWTh+f/wC5pDJkhwhzc= Subject: patch "kobject: Make sure the parent does not get released before its" added to driver-core-linus To: heikki.krogerus@linux.intel.com, brendanhiggins@google.com, gregkh@linuxfoundation.org, naresh.kamboju@linaro.org, rafael.j.wysocki@intel.com, rafael@kernel.org, rdunlap@infradead.org, rong.a.chen@intel.com, stable@vger.kernel.org From: Date: Thu, 21 May 2020 11:01:37 +0200 Message-ID: <159005169722757@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This is a note to let you know that I've just added the patch titled kobject: Make sure the parent does not get released before its to my driver-core git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git in the driver-core-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >From 4ef12f7198023c09ad6d25b652bd8748c965c7fa Mon Sep 17 00:00:00 2001 From: Heikki Krogerus Date: Wed, 13 May 2020 18:18:40 +0300 Subject: kobject: Make sure the parent does not get released before its children In the function kobject_cleanup(), kobject_del(kobj) is called before the kobj->release(). That makes it possible to release the parent of the kobject before the kobject itself. To fix that, adding function __kboject_del() that does everything that kobject_del() does except release the parent reference. kobject_cleanup() then calls __kobject_del() instead of kobject_del(), and separately decrements the reference count of the parent kobject after kobj->release() has been called. Reported-by: Naresh Kamboju Reported-by: kernel test robot Fixes: 7589238a8cf3 ("Revert "software node: Simplify software_node_release() function"") Suggested-by: "Rafael J. Wysocki" Signed-off-by: Heikki Krogerus Reviewed-by: Rafael J. Wysocki Reviewed-by: Brendan Higgins Tested-by: Brendan Higgins Acked-by: Randy Dunlap Link: https://lore.kernel.org/r/20200513151840.36400-1-heikki.krogerus@linux.intel.com Cc: stable Signed-off-by: Greg Kroah-Hartman --- lib/kobject.c | 30 ++++++++++++++++++++---------- 1 file changed, 20 insertions(+), 10 deletions(-) diff --git a/lib/kobject.c b/lib/kobject.c index 83198cb37d8d..2bd631460e18 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -599,14 +599,7 @@ int kobject_move(struct kobject *kobj, struct kobject *new_parent) } EXPORT_SYMBOL_GPL(kobject_move); -/** - * kobject_del() - Unlink kobject from hierarchy. - * @kobj: object. - * - * This is the function that should be called to delete an object - * successfully added via kobject_add(). - */ -void kobject_del(struct kobject *kobj) +static void __kobject_del(struct kobject *kobj) { struct kernfs_node *sd; const struct kobj_type *ktype; @@ -625,9 +618,23 @@ void kobject_del(struct kobject *kobj) kobj->state_in_sysfs = 0; kobj_kset_leave(kobj); - kobject_put(kobj->parent); kobj->parent = NULL; } + +/** + * kobject_del() - Unlink kobject from hierarchy. + * @kobj: object. + * + * This is the function that should be called to delete an object + * successfully added via kobject_add(). + */ +void kobject_del(struct kobject *kobj) +{ + struct kobject *parent = kobj->parent; + + __kobject_del(kobj); + kobject_put(parent); +} EXPORT_SYMBOL(kobject_del); /** @@ -663,6 +670,7 @@ EXPORT_SYMBOL(kobject_get_unless_zero); */ static void kobject_cleanup(struct kobject *kobj) { + struct kobject *parent = kobj->parent; struct kobj_type *t = get_ktype(kobj); const char *name = kobj->name; @@ -684,7 +692,7 @@ static void kobject_cleanup(struct kobject *kobj) if (kobj->state_in_sysfs) { pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n", kobject_name(kobj), kobj); - kobject_del(kobj); + __kobject_del(kobj); } if (t && t->release) { @@ -698,6 +706,8 @@ static void kobject_cleanup(struct kobject *kobj) pr_debug("kobject: '%s': free name\n", name); kfree_const(name); } + + kobject_put(parent); } #ifdef CONFIG_DEBUG_KOBJECT_RELEASE -- 2.26.2