From mboxrd@z Thu Jan 1 00:00:00 1970 From: Elias Vanderstuyft 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> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Sender: linux-kernel-owner@vger.kernel.org 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 List-Id: linux-input@vger.kernel.org If a new (id =3D=3D -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 Mal=C3=BD 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, uns= igned int cmd, return -EFAULT; =20 error =3D input_ff_upload(dev, &effect, file); + if (error) + return error; =20 if (put_user(effect.id, &(((struct ff_effect __user *)p)->id))) return -EFAULT; =20 - return error; + return 0; } =20 /* Multi-number variable-length handlers */ --=20 1.8.3.1