From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751751AbaC2MQv (ORCPT ); Sat, 29 Mar 2014 08:16:51 -0400 Received: from mail-ee0-f45.google.com ([74.125.83.45]:57023 "EHLO mail-ee0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751432AbaC2MQt (ORCPT ); Sat, 29 Mar 2014 08:16:49 -0400 From: Elias Vanderstuyft To: dmitry.torokhov@gmail.com Cc: Elias Vanderstuyft , Anssi Hannula , =?UTF-8?q?Michal=20Mal=C3=BD?= , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/1] Input: don't modify the id of ioctl-provided ff effect on upload failure Date: Sat, 29 Mar 2014 13:16:36 +0100 Message-Id: <1396095396-23551-1-git-send-email-elias.vds@gmail.com> X-Mailer: git-send-email 1.8.3.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If a new (id == -1) ff effect was uploaded from userspace, ff-core.c::input_ff_upload() will have assigned a positive number to the new effect id. Currently, evdev.c::evdev_do_ioctl() will save this new id to userspace, regardless of whether the upload succeeded or not. On upload failure, this can be confusing because the dev->ff->effects[] array will not contain an element at the index of that new effect id. This patch fixes this by leaving the id unchanged after upload fails. Note: Unfortunately applications should still expect changed effect id for quite some time. This has been discussed on: http://www.mail-archive.com/linux-input@vger.kernel.org/msg08513.html ("ff-core effect id handling in case of a failed effect upload") Suggested-by: Dmitry Torokhov Signed-off-by: Elias Vanderstuyft Cc: Anssi Hannula Cc: Michal Malý Cc: linux-input@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- v2: Only added one line to the commit message to say what this patch actually does, instead of only stating the reason why it's submitted. drivers/input/evdev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c index a06e125..ce953d8 100644 --- a/drivers/input/evdev.c +++ b/drivers/input/evdev.c @@ -954,11 +954,13 @@ static long evdev_do_ioctl(struct file *file, unsigned int cmd, return -EFAULT; error = input_ff_upload(dev, &effect, file); + if (error) + return error; if (put_user(effect.id, &(((struct ff_effect __user *)p)->id))) return -EFAULT; - return error; + return 0; } /* Multi-number variable-length handlers */ -- 1.8.3.1