Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751465AbbHQEQb (ORCPT ); Mon, 17 Aug 2015 00:16:31 -0400 Received: from mx2.suse.de ([195.135.220.15]:55676 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750839AbbHQEQa (ORCPT ); Mon, 17 Aug 2015 00:16:30 -0400 Date: Mon, 17 Aug 2015 06:16:34 +0200 From: Borislav Petkov To: yalin wang Cc: Thomas Gleixner , mingo@redhat.com, hpa@zytor.com, x86@kernel.org, open list , Will Deacon Subject: Re: [x86] copy_from{to}_user question Message-ID: <20150817041634.GA9387@nazgul.tnic> References: <7FD389F5-C677-4439-8082-EB0CAE2814F6@gmail.com> <20150812100738.GA14020@nazgul.tnic> <9232AF8E-87A3-40B2-852A-D07889F9E1B4@gmail.com> <20150813164302.GA15881@nazgul.tnic> <6ABF6137-251E-47EF-B824-AC77C9C9AB24@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <6ABF6137-251E-47EF-B824-AC77C9C9AB24@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1308 Lines: 36 On Mon, Aug 17, 2015 at 11:27:01AM +0800, yalin wang wrote: > i just want the x86 copy_from{to,in}_user() function have > the same behaviour as other platforms. Back to the original question from 2 mails ago: How else would we be able to use the same function in copy_to and copy_from variants? > and can disclose potential BUGs in kernel, if do like this. Back to my other question: Do you have any real life examples where you can trigger such bugs or is this only "potential"? IOW, what I *think* you're trying to do sounds to me like unnecessary complication with no apparent gain *at* *all*. So show me why you want to do it: code it up, trigger a bug and show me why your version is better. No "but but it might be a good idea", no "potentially maybe", none of that maybe stuff. Write it, send it with instructions how someone else can apply it and trigger the issue. Ok? -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/