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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 A07F7C433E1 for ; Sat, 23 May 2020 14:04:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 776BA207F7 for ; Sat, 23 May 2020 14:04:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590242661; bh=3GrDS2+LfV+5Q1mKglHDFkYxRwI4AAtXMEEXKunzq3s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=MkOH+RU4GTQCAbFgfmcKPF5a/BDQgiX3GPx3opBFu/uAXh1Llv6hVlAqvagBlZFfm Yj369gWPtBmrtuN/LmICocH4jbu4F0MHvD6I3gKb2xbFdaMgI41rVqj0G2rYn65nbT /i+Uu2sUgFqSesp3IeHSWV3DvXiTHdP9QRmjho1A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387860AbgEWOEP (ORCPT ); Sat, 23 May 2020 10:04:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:36424 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387529AbgEWOEO (ORCPT ); Sat, 23 May 2020 10:04:14 -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 75BB62072C; Sat, 23 May 2020 14:04:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590242653; bh=3GrDS2+LfV+5Q1mKglHDFkYxRwI4AAtXMEEXKunzq3s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YVZj5q+FKln2NEIeK0OZ41mzcqT7ILj9jfKpLGM4QNnhZoYBpGvPFOkPtDHvIMfGQ Jxv1rT7u92dlCkjmMv86YzODMCHGzSWqCPTV3Wc8x+ffZCX15ylxAINbASOUIPAhFA cpW/4oHZO4BEgq0cwgIOYKO5g9fRI6IH4NJKep9M= Date: Sat, 23 May 2020 16:04:11 +0200 From: Greg Kroah-Hartman To: Guenter Roeck Cc: Heikki Krogerus , linux-kernel@vger.kernel.org, Naresh Kamboju , kernel test robot , Brendan Higgins , Randy Dunlap , "Rafael J. Wysocki" Subject: Re: [PATCH] kobject: Make sure the parent does not get released before its children Message-ID: <20200523140411.GA114366@kroah.com> References: <20200513151840.36400-1-heikki.krogerus@linux.intel.com> <20200523132101.GA76443@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200523132101.GA76443@roeck-us.net> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, May 23, 2020 at 06:21:01AM -0700, Guenter Roeck wrote: > On Wed, May 13, 2020 at 06:18:40PM +0300, Heikki Krogerus wrote: > > 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 > > s/kboject/kobject/ > > > 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"") > > Cc: Brendan Higgins > > Cc: Randy Dunlap > > 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 > > Tested-by: Randy Dunlap > > 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. Ugh, ok, just when I send Linus a pull request. Let me go fix that... greg k-h