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 CA673C433E0 for ; Sat, 23 May 2020 15:13:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A080E2072C for ; Sat, 23 May 2020 15:13:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590246789; bh=AzSatURo6hgJG9hfj5elmyoScqdGFmOA/nnPjlEkePk=; h=Subject:To:From:Date:List-ID:From; b=DJZcMB/rg2fqa1u/aPWY8ODFXw7HI5EWBRU2ipkWczfQbJacP3e1YwOGeXOX9YcNL 7mm5EYmrZ6JcR4b/4VymNDg1TyQaFJp4q1D94Z6K38t3DsWeX4hR6WxLCCrpczVkzX E67cu1NEpGyvVN0iNc3T+rnzv3l3UmfkhJWF/wGU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387883AbgEWPNJ (ORCPT ); Sat, 23 May 2020 11:13:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:48952 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387867AbgEWPNJ (ORCPT ); Sat, 23 May 2020 11:13:09 -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 A71FB2071C; Sat, 23 May 2020 15:13:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590246787; bh=AzSatURo6hgJG9hfj5elmyoScqdGFmOA/nnPjlEkePk=; h=Subject:To:From:Date:From; b=NVSYhukFVUmhErpg/YtnsCC4tfZMUAkU+Ndg11Wfuyi7NncxrodA7fnBtX/GEoO4I U7Vmlj05pDc8peUis7KURVfDbn/px6K/mJPU39B62By3axAWklPw02D1/sjogYeyk1 3KD6uUfCNZ4tSlpUof2mt0ESZ6eBQXcX07/Iz224= Subject: patch "Revert "kobject: Make sure the parent does not get released before" added to driver-core-linus To: gregkh@linuxfoundation.org, brendanhiggins@google.com, heikki.krogerus@linux.intel.com, linux@roeck-us.net, naresh.kamboju@linaro.org, rafael@kernel.org, rdunlap@infradead.org, rong.a.chen@intel.com, stable@vger.kernel.org From: Date: Sat, 23 May 2020 17:13:04 +0200 Message-ID: <159024678421391@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 Revert "kobject: Make sure the parent does not get released before 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 e6764aa0e5530066dd969eccea2a1a7d177859a8 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Sat, 23 May 2020 17:11:11 +0200 Subject: Revert "kobject: Make sure the parent does not get released before its children" This reverts commit 4ef12f7198023c09ad6d25b652bd8748c965c7fa. Guenter reports: All my arm64be (arm64 big endian) boot tests crash with this patch applied. Reverting it fixes the problem. Crash log and bisect results (from pending-fixes branch) below. And also: arm64 images don't crash but report lots of "poison overwritten" backtraces like the one below. On arm, I see "refcount_t: underflow", also attached. I didn't bisect those, but given the context I would suspect the same culprit. Reported-by: Guenter Roeck Link: https://lore.kernel.org/r/20200513151840.36400-1-heikki.krogerus@linux.intel.com Cc: Naresh Kamboju Cc: kernel test robot Cc: "Rafael J. Wysocki" Cc: Heikki Krogerus Cc: Brendan Higgins Cc: Randy Dunlap Cc: stable Signed-off-by: Greg Kroah-Hartman --- lib/kobject.c | 30 ++++++++++-------------------- 1 file changed, 10 insertions(+), 20 deletions(-) diff --git a/lib/kobject.c b/lib/kobject.c index 2bd631460e18..83198cb37d8d 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -599,7 +599,14 @@ int kobject_move(struct kobject *kobj, struct kobject *new_parent) } EXPORT_SYMBOL_GPL(kobject_move); -static void __kobject_del(struct kobject *kobj) +/** + * 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 kernfs_node *sd; const struct kobj_type *ktype; @@ -618,23 +625,9 @@ static 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); /** @@ -670,7 +663,6 @@ 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; @@ -692,7 +684,7 @@ 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) { @@ -706,8 +698,6 @@ 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