| Message ID | 1396095396-23551-1-git-send-email-elias.vds@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, Mar 29, 2014 at 01:16:36PM +0100, Elias Vanderstuyft wrote: > 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 <dmitry.torokhov@gmail.com> > Signed-off-by: Elias Vanderstuyft <elias.vds@gmail.com> > Cc: Anssi Hannula <anssi.hannula@iki.fi> > Cc: Michal Malý <madcatxster@devoid-pointer.net> > Cc: linux-input@vger.kernel.org > Cc: linux-kernel@vger.kernel.org Applied, thank you, and sorry for the delay. > --- > 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 >
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 */
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 <dmitry.torokhov@gmail.com> Signed-off-by: Elias Vanderstuyft <elias.vds@gmail.com> Cc: Anssi Hannula <anssi.hannula@iki.fi> Cc: Michal Malý <madcatxster@devoid-pointer.net> 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(-)