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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 B99F4C43387 for ; Tue, 18 Dec 2018 23:44:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F567218A2 for ; Tue, 18 Dec 2018 23:44:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727657AbeLRXoz (ORCPT ); Tue, 18 Dec 2018 18:44:55 -0500 Received: from ozlabs.org ([203.11.71.1]:54157 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726746AbeLRXoz (ORCPT ); Tue, 18 Dec 2018 18:44:55 -0500 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPSA id 43KF4P1jyFz9s3Z; Wed, 19 Dec 2018 10:44:53 +1100 (AEDT) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au From: Michael Ellerman To: Rob Herring , Frank Rowand Cc: mwb@linux.vnet.ibm.com, linuxppc-dev , Tyrel Datwyler , tlfalcon@linux.vnet.ibm.com, minkim@us.ibm.com, devicetree@vger.kernel.org, "linux-kernel\@vger.kernel.org" Subject: Re: [PATCH v2 2/2] of: __of_detach_node() - remove node from phandle cache In-Reply-To: References: <1545033396-24485-1-git-send-email-frowand.list@gmail.com> <1545033396-24485-3-git-send-email-frowand.list@gmail.com> <871s6gv30z.fsf@concordia.ellerman.id.au> <893d9327-4353-066d-2efa-414a3db4c282@gmail.com> <6b6a3d11-e60a-f55c-04fa-deafdd58ccec@gmail.com> Date: Wed, 19 Dec 2018 10:44:53 +1100 Message-ID: <87pntys8lm.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Rob Herring writes: > On Tue, Dec 18, 2018 at 2:33 PM Frank Rowand wrote: >> >> On 12/18/18 12:09 PM, Frank Rowand wrote: >> > On 12/18/18 12:01 PM, Rob Herring wrote: >> >> On Tue, Dec 18, 2018 at 12:57 PM Frank Rowand wrote: >> >>> >> >>> On 12/17/18 2:52 AM, Michael Ellerman wrote: >> >>>> Hi Frank, >> >>>> >> >>>> frowand.list@gmail.com writes: >> >>>>> From: Frank Rowand >> >>>>> >> >>>>> Non-overlay dynamic devicetree node removal may leave the node in >> >>>>> the phandle cache. Subsequent calls to of_find_node_by_phandle() >> >>>>> will incorrectly find the stale entry. Remove the node from the >> >>>>> cache. >> >>>>> >> >>>>> Add paranoia checks in of_find_node_by_phandle() as a second level >> >>>>> of defense (do not return cached node if detached, do not add node >> >>>>> to cache if detached). >> >>>>> >> >>>>> Reported-by: Michael Bringmann >> >>>>> Signed-off-by: Frank Rowand >> >>>>> --- >> >>>> >> >>>> Similarly here can we add: >> >>>> >> >>>> Fixes: 0b3ce78e90fc ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()") >> >>> >> >>> Yes, thanks. >> >>> >> >>> >> >>>> Cc: stable@vger.kernel.org # v4.17+ >> >>> >> >>> Nope, 0b3ce78e90fc does not belong in stable (it is a feature, not a bug >> >>> fix). So the bug will not be in stable. >> >> >> >> 0b3ce78e90fc landed in v4.17, so Michael's line above is correct. >> >> Annotating it with 4.17 only saves Greg from trying and then emailing >> >> us to backport this patch as it wouldn't apply. >> > >> > Thanks for the correction. I was both under-thinking and over-thinking, >> > ending up with an incorrect answer. >> > >> > Can you add the Cc: to version 3 patch comments (both 1/2 and 2/2) or do >> > you want me to re-spin? >> >> Now that my thinking has been straightened out, a little bit more checking >> for the other pre-requisite patches show: >> >> v4.18: commit b9952b5218ad ("of: overlay: update phandle cache on overlay apply and remove") >> v4.19: commit e54192b48da7 ("of: fix phandle cache creation for DTs with no phandles") >> >> These can be addressed by changing the "Cc:" to ... # v4.19+ >> because stable v4.17.* and v4.18.* are end of life. > > EOL shouldn't factor into it. There's always the possibility someone > else picks any kernel version. Yeah, there are other stable branches out there, so the tag should point to the correct version regardless of whether it's currently EOL on kernel.org. >> Or the pre-requisites can be listed: >> >> # v4.17: b9952b5218ad of: overlay: update phandle cache >> # v4.17: e54192b48da7 of: fix phandle cache creation >> # v4.17 >> >> # v4.18: e54192b48da7 of: fix phandle cache creation >> # v4.18 >> >> # v4.19+ >> >> Do you have a preference? > > I think we just list v4.17 and be done with it. Yep, anyone who wants to backport it can work it out, or ask us. cheers