On Sat, May 22, 2021 at 01:34:29PM +0800, Nguyen Dinh Phi wrote: > This commit to fix the following sparse warning: > incorrect type in assignment (different address spaces) > expected void *[assigned] userdata > got void [noderef] __user *userdata > > Signed-off-by: Nguyen Dinh Phi <phind.uet@xxxxxxxxx> > --- > .../staging/vc04_services/interface/vchiq_arm/vchiq_arm.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > index afbf01b7364c..2a4fc599f977 100644 > --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c > @@ -960,7 +960,10 @@ static int vchiq_irq_queue_bulk_tx_rx(struct vchiq_instance *instance, > current->pid); > userdata = &waiter->bulk_waiter; > } else { > - userdata = args->userdata; > + if (copy_from_user(userdata, args->userdata, sizeof(args->userdata))) { The contents of userdata (local variable of type void *) is uninitialized at that point. Just what do you think that call of copy_from_user() would do?