Hi Sasha, On Mon, Oct 22, 2018 at 06:19:05AM -0400, Sasha Levin wrote: > From: Dmitry Torokhov <dmitry.torok...@gmail.com> > > [ Upstream commit 36d2582ff235b4e01ad64a734c877a52dc762d9c ] > > Large writes to evdev interface may cause rcu stalls. Let's add > cond_resched() to the loop to avoid this.
This is not needed in stable: - the interfaces are not accessible for unprivileged users so there is no DOS concerns - the issue can only happen on non-preemptible kernels - the issue only showed up with synthetic test and not real life use cases - this is not a regression The same goes to similar patches to mousedev, joydev and uinput that you autoselected. Thanks. > > Reviewed-by: Paul E. McKenney <paul...@linux.ibm.com> > Signed-off-by: Dmitry Torokhov <dmitry.torok...@gmail.com> > Signed-off-by: Sasha Levin <sas...@kernel.org> > --- > drivers/input/evdev.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c > index c81c79d01d93..718d5622267d 100644 > --- a/drivers/input/evdev.c > +++ b/drivers/input/evdev.c > @@ -564,6 +564,7 @@ static ssize_t evdev_write(struct file *file, const char > __user *buffer, > > input_inject_event(&evdev->handle, > event.type, event.code, event.value); > + cond_resched(); > } > > out: > -- > 2.17.1 > -- Dmitry
