From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753119AbcJCOZ7 (ORCPT ); Mon, 3 Oct 2016 10:25:59 -0400 Received: from mout.web.de ([212.227.17.11]:54943 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753007AbcJCOZw (ORCPT ); Mon, 3 Oct 2016 10:25:52 -0400 Subject: Re: KVM: s390: Use memdup_user() rather than duplicating code To: Geert Uytterhoeven References: <82b84c9c-38a4-4d17-910f-312668dbae01@users.sourceforge.net> <73d5a586-2178-a311-f19c-c16c6e8cbb22@users.sourceforge.net> <9ee60162-110b-1305-5a97-624de425d072@users.sourceforge.net> Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, =?UTF-8?Q?Christian_Borntr=c3=a4ger?= , Cornelia Huck , David Hildenbrand , Heiko Carstens , Martin Schwidefsky , Paolo Bonzini , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , LKML , kernel-janitors@vger.kernel.org, Julia Lawall , Walter Harms From: SF Markus Elfring Message-ID: Date: Mon, 3 Oct 2016 16:25:34 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K0:V6o9JC9PMG++7KlL2GlDDt2EEuZpMUfBlFF/bxXv1NgzrPvLAtX QTAukI0Dx8kDX6t4OuPE+25RKsk08Wd9ZK1XQKXT4WupVXziBii6MGzEBKy3N0IGWVh9njg zFyoFcqMxtgg7SoBF1FuhjZ64ffN0GzNf41bTzbJGlnrhKfEtCP7g5QlmHcOczOov8HT5S4 fRp4qveaOOF0+XsQSd+EQ== X-UI-Out-Filterresults: notjunk:1;V01:K0:vHwfbk/ssHk=:yVfRWD7XUSXEJAmiKp2ffN glCPfrqethRAiNjW0fRTk7Wy9+kjU5c4sSvUG1/Vs64GjyC0u5bzVKQn5d+bPcjaSarDy4PQe Pr/a2iXSyC/5o49Mboq0hrhgThnR3MctL7Ctcd/osrR4B7EhGc9ID6cVUGu+AkKSgxFpAESVS pS1MNsEpIQyJXyxtEm//LhyxigWteNNw1Lr8IrIf2DAdtbMqkXK6z3XgUfGvNn9iUAKfw2iKd XzzD020nyW/+50FB3NWt7D6xqUuFcpgWLk6zqaKcCSYzn+c6S+wFeFUib7rx6pwd/dv5UBC+s NhnTAcbtwQlHfe5tEY4MnmaPGz6yObx9MJhJwuf2bCabydHngfFa+qkKDQaizaOjYvw6/BGwZ Qn1yOVX91lE2XXIbKSip6oO4BwLAWZggT+9i1IFiy4YO23suNFfI2SGCXt1Q42DpajyHK0u6M +K/ugT8IDeeex/bAcLYtaEHo27eV0w0mkfbnTpn752RvKGoZojQCw8x/BOEqT9qwFAEBR5w9I q+vd+JDrSPHuelcDS8TTBgHKs1WdARdeXcbZtHkdFBvHxRDnm0eOop0z27UZ2I5UPPURjnmF5 9Mr4wG3ojtonZLj3fxWE4OXFnCB79vuO+Pju0I1pDMMFCjxaPAnnISdGLJ01Mebg7J6CY/V8T trjJIbmdxVp1d3cBZnDX4jpbHVTJ3EOhcg9nPPB8hS6J4A94Gm1PXEmvTb4FpI2EWo1TPVnmZ 9/snYIRiF19wiUvVfgX9HCi630N0Sd1PHo3KFEziZ+FvgmwWtKIkkdZ/F5L9yg0lFZQdIFyda BDtHi1b Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> * Does there really a probability remain that an inappropriate product >> would be calculated here (as the situation was before my two update steps >> for this software module)? > > Perhaps not. Hence my "Probably not an issue here, ...". Thanks for your clarification. >> * Can it be that you are looking for a variant of a function like "memdup_user" >> where values can be passed as separate parameters "count" and "size" so that >> the needed multiplication and corresponding overflow check would be performed >> together as desired? > > If there are enough uses, and people like it, adding memdup_user_array() > may be a good idea... How are the chances of such an addition for the Linux programming interface? > P.S. Why do your questions make me think of a scientific paper? ;-) Would you like to recommend any for further reading? ;-) Regards, Markus