From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi1-f200.google.com (mail-oi1-f200.google.com [209.85.167.200]) by kanga.kvack.org (Postfix) with ESMTP id 29B666B3158 for ; Fri, 23 Nov 2018 09:48:18 -0500 (EST) Received: by mail-oi1-f200.google.com with SMTP id n10-v6so5611389oib.5 for ; Fri, 23 Nov 2018 06:48:18 -0800 (PST) Received: from www262.sakura.ne.jp (www262.sakura.ne.jp. [202.181.97.72]) by mx.google.com with ESMTPS id r128si6399934oig.167.2018.11.23.06.48.16 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 23 Nov 2018 06:48:16 -0800 (PST) Subject: Re: [PATCH] mm: debug: Fix a width vs precision bug in printk References: <20181123072135.gqvblm2vdujbvfjs@kili.mountain> <20181123090125.GC8625@dhcp22.suse.cz> <20181123143605.GB2970@unbuntlaptop> From: Tetsuo Handa Message-ID: Date: Fri, 23 Nov 2018 23:48:06 +0900 MIME-Version: 1.0 In-Reply-To: <20181123143605.GB2970@unbuntlaptop> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Dan Carpenter , Michal Hocko Cc: Andrew Morton , Pavel Tatashin , Alexander Duyck , Matthew Wilcox , linux-mm@kvack.org, kernel-janitors@vger.kernel.org On 2018/11/23 23:36, Dan Carpenter wrote: > On Fri, Nov 23, 2018 at 10:01:25AM +0100, Michal Hocko wrote: >> On Fri 23-11-18 10:21:35, Dan Carpenter wrote: >>> We had intended to only print dentry->d_name.len characters but there is >>> a width vs precision typo so if the name isn't NUL terminated it will >>> read past the end of the buffer. >> >> OK, it took me quite some time to grasp what you mean here. The code >> works as expected because d_name.len and dname.name are in sync so there >> no spacing going to happen. Anyway what you propose is formally more >> correct I guess. >> > > Yeah. If we are sure that the name has a NUL terminator then this > change has no effect. There seems to be %pd which is designed for printing "struct dentry".