From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Hutterer Subject: Re: [PATCH 2/4] Input: introduce ABS_MAX2/CNT2 and friends Date: Thu, 19 Dec 2013 09:55:04 +1000 Message-ID: <20131218235504.GA17958@yabbi.redhat.com> References: <1387295334-1744-1-git-send-email-dh.herrmann@gmail.com> <1387295334-1744-3-git-send-email-dh.herrmann@gmail.com> <20131218234009.GA9360@yabbi.redhat.com> <1950536.BXYYX85NB4@dtor-d630.eng.vmware.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from leo.clearchain.com ([199.73.29.74]:35480 "EHLO mail.clearchain.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751356Ab3LRXwY (ORCPT ); Wed, 18 Dec 2013 18:52:24 -0500 Content-Disposition: inline In-Reply-To: <1950536.BXYYX85NB4@dtor-d630.eng.vmware.com> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Dmitry Torokhov Cc: David Herrmann , linux-input@vger.kernel.org, Jiri Kosina , Benjamin Tissoires , Antonio Ospite , linux-kernel@vger.kernel.org, input-tools@lists.freedesktop.org On Wed, Dec 18, 2013 at 03:48:37PM -0800, Dmitry Torokhov wrote: > On Thursday, December 19, 2013 09:40:09 AM Peter Hutterer wrote: > > > + memset(&abs, 0, sizeof(abs)); > > > + for (i = valid_cnt; i < cnt; ++i) > > > + if (copy_to_user(&pinfo->info[i], &abs, sizeof(abs))) > > > + return -EFAULT; > > > + > > > + return 0; > > > > why don't you return the number of valid copied axes to the user? > > that seems better even than forcing the remainder to 0. > > Well, if your program messed up buffers that it faulted we do not know > for sure if data that did not cause fault ended up where it should have > or if it smashed something else. This condition I think should be > signaled early. not 100% sure I understand but I wasn't proposing to remove the -EFAULT, i was proposing to replace "return 0" with "return valid_cnt". Cheers, Peter