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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 968E4C433E6 for ; Tue, 23 Feb 2021 20:09:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 51AA264EBB for ; Tue, 23 Feb 2021 20:09:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234143AbhBWUI2 (ORCPT ); Tue, 23 Feb 2021 15:08:28 -0500 Received: from mout.kundenserver.de ([212.227.126.134]:38615 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232377AbhBWUGi (ORCPT ); Tue, 23 Feb 2021 15:06:38 -0500 Received: from [192.168.1.155] ([77.9.11.4]) by mrelayeu.kundenserver.de (mreue009 [212.227.15.167]) with ESMTPSA (Nemesis) id 1MjSHa-1lhxDs1SHa-00kzQO; Tue, 23 Feb 2021 20:54:18 +0100 Subject: Re: [PATCH] lib: vsprintf: check for NULL device_node name in device_node_string() To: Andy Shevchenko , "Enrico Weigelt, metux IT consult" Cc: linux-kernel@vger.kernel.org, pmladek@suse.com, rostedt@goodmis.org, sergey.senozhatsky@gmail.com, linux@rasmusvillemoes.dk, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org References: <20210217121543.13010-1-info@metux.net> From: "Enrico Weigelt, metux IT consult" Message-ID: <1a010bef-4b13-06ea-e153-e76c4afe0ad1@metux.net> Date: Tue, 23 Feb 2021 20:54:16 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: tl Content-Transfer-Encoding: 8bit X-Provags-ID: V03:K1:YArMsHWW8jRv/C9fmYWhQh5832I+zbo3b4sJZ+Kji3zOWKTF5qJ F+3UJWlMcxIz05Z8xghblfwXa5/Ya/GhCGFQjxK2oyzy+1BN/G18Lo2hqQjWBVLf7X9vk1l 471KYi6PVGLAEE8r9tjU3Gm/UutBPxFlWliPCBevOjF5e4lFDSoVClZq9v3xcYjhHkWzCqd 0HuQvdlNxwobVrdodbX9g== X-UI-Out-Filterresults: notjunk:1;V03:K0:ApSgkXDKLug=:myUB82SlknbqEKvr3bQCXL bm6DgRYOF4GP5zpTkqChvX1ttjZovPU45MeTYYjKCIP7E6maerdyDXCDIuirAhhLzqKQdb6mc zab/NEOw23pNWSH9f6h3zvfn/ABeYzwscXLfmpcJXomF0XNFkR9M0tbP4BDr0FTk6ZxHBXK25 2WOWNobfJGquJL/ULjpvgdOrxPRxfOcm7vVZ03hVGTB83umemdKvZ5LMd4rXC8j/WmU3UOa4O FXWGUHeQH75DKwKyjknYd9iNUYy3AadP/H+vjZblae1MBs6L0OGHbSBZWqAstCt3bpaa12Vdi bymro8tKK4EfhPMXZ/7yLZ5GujcuSFgwy27DahCYeYHUl2p7Utoma7xeQ8E6KCKQNTBFmGyzn gRCyChLS/Dxd46IcEOcGJ24ZYL0/1ALUSKfa7GCj1FZB5dZTz9dEaacKu7kIQ Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 17.02.21 14:50, Andy Shevchenko wrote: > On Wed, Feb 17, 2021 at 01:15:43PM +0100, Enrico Weigelt, metux IT consult wrote: >> Under rare circumstances it may happen that a device node's name is NULL >> (most likely kernel bug in some other place). > > What circumstances? How can I reproduce this? More information, please! Observed it when applying a broken overlay. (sorry, didn't keep that broken code :o). In this case, the device_node was left without a name (pointing to NULL). >> + pr_warn("device_node without name. Kernel bug ?\n"); > > If it's not once, then it's possible to have log spammed with this, right? It only has occoured once for me. I don't think spamming could happen, unless one's hacking deeply in the oftree code. >> + p = ""; > > We have different standard de facto for NULL pointers to be printed. Actually > if you wish, you may gather them under one definition (maybe somewhere under > printk) and export to everybody to use. Seen it in Petr's reply ... going to use that in v2. --mtx -- --- Hinweis: unverschlüsselte E-Mails können leicht abgehört und manipuliert werden ! Für eine vertrauliche Kommunikation senden Sie bitte ihren GPG/PGP-Schlüssel zu. --- Enrico Weigelt, metux IT consult Free software and Linux embedded engineering info@metux.net -- +49-151-27565287