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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 54AF7C070C3 for ; Mon, 15 Oct 2018 01:06:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1721E20659 for ; Mon, 15 Oct 2018 01:06:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1721E20659 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=perches.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 S1726507AbeJOItk (ORCPT ); Mon, 15 Oct 2018 04:49:40 -0400 Received: from smtprelay0235.hostedemail.com ([216.40.44.235]:58313 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726357AbeJOItk (ORCPT ); Mon, 15 Oct 2018 04:49:40 -0400 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay03.hostedemail.com (Postfix) with ESMTP id B6F8C83777EE; Mon, 15 Oct 2018 01:06:43 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: home21_5785f54ad7d03 X-Filterd-Recvd-Size: 3091 Received: from XPS-9350.home (unknown [47.151.153.53]) (Authenticated sender: joe@perches.com) by omf02.hostedemail.com (Postfix) with ESMTPA; Mon, 15 Oct 2018 01:06:41 +0000 (UTC) Message-ID: Subject: Re: [PATCH v3 13/18] of: overlay: check prevents multiple fragments touching same property From: Joe Perches To: frowand.list@gmail.com, 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 Date: Sun, 14 Oct 2018 18:06:40 -0700 In-Reply-To: <1539563070-12969-14-git-send-email-frowand.list@gmail.com> References: <1539563070-12969-1-git-send-email-frowand.list@gmail.com> <1539563070-12969-14-git-send-email-frowand.list@gmail.com> Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.30.1-1build1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2018-10-14 at 17:24 -0700, frowand.list@gmail.com wrote: > From: Frank Rowand > > Add test case of two fragments updating the same property. After > adding the test case, the system hangs at end of boot, after > after slub stack dumps from kfree() in crypto modprobe code. [] > -static int check_changeset_dup_add_node(struct overlay_changeset *ovcs) > +static int changeset_dup_entry_check(struct overlay_changeset *ovcs) > { > - struct of_changeset_entry *ce_1, *ce_2; > - char *fn_1, *fn_2; > - int name_match; > + struct of_changeset_entry *ce_1; > + int dup_entry = 0; > > list_for_each_entry(ce_1, &ovcs->cset.entries, node) { > - > - if (ce_1->action == OF_RECONFIG_ATTACH_NODE || > - ce_1->action == OF_RECONFIG_DETACH_NODE) { > - > - ce_2 = ce_1; > - list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) { > - if (ce_2->action == OF_RECONFIG_ATTACH_NODE || > - ce_2->action == OF_RECONFIG_DETACH_NODE) { > - /* inexpensive name compare */ > - if (!of_node_cmp(ce_1->np->full_name, > - ce_2->np->full_name)) { > - /* expensive full path name compare */ > - fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np); > - fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np); > - name_match = !strcmp(fn_1, fn_2); > - kfree(fn_1); > - kfree(fn_2); > - if (name_match) { > - pr_err("ERROR: multiple overlay fragments add and/or delete node %pOF\n", > - ce_1->np); > - return -EINVAL; > - } > - } > - } > - } > - } > + dup_entry |= find_dup_cset_node_entry(ovcs, ce_1); > + dup_entry |= find_dup_cset_prop(ovcs, ce_1); I think this is worse performance than before. This now walks all entries when before it would return -EINVAL directly when it found a match.