From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luis de Bethencourt Subject: Re: [PATCH] HID: hiddev: fix returned errno code in hiddev_connect() Date: Sat, 03 Oct 2015 22:34:41 +0100 Message-ID: <561049F1.5040507@osg.samsung.com> References: <1443606749-6028-1-git-send-email-luisbg@osg.samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Jiri Kosina Cc: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, linux-input@vger.kernel.org List-Id: linux-input@vger.kernel.org On 30/09/15 20:40, Jiri Kosina wrote: > On Wed, 30 Sep 2015, Luis de Bethencourt wrote: > >> The driver is using -1 instead of the -ENOMEM defined macro to specify >> that a buffer allocation failed. Since the error number is propagated, >> the caller will get a -EPERM which is the wrong error condition. > > Generally I agree that the more specific errno, the better. > > But I am not really sure where you are seeing the bug (mapping to -EPERM) > in this case? I think the only caller of hiddev_connect() should be > hid_connect(), and the only thing that guy cares about whether individual > callbacks succeed or fail, so that it sets hdev->clamed flags accordingly. > > Could you please be more specific about the -EPERM mapping you are talking > about? > > Thanks, > I agree with you. The only caller of hiddev_connect() only checks if the callback succeded. It checks if the return < 0. What I meant is that -1 means -EPERM. [0] This patch is purely about the correctness of using -ENOMEM. The word "propagated" was not the best way to describe this problem. I could edit the commit message if you would like. Thanks for the review, Luis [0] http://lxr.free-electrons.com/source/include/uapi/asm-generic/errno-base.h#L15