On Tue, Jul 21, 2020 at 07:23:26AM +0200, Christoph Hellwig wrote: > On Tue, Jul 21, 2020 at 04:40:16AM +0200, Luc Van Oostenryck wrote: > > > req.pid = current->pid; > > > req.cmd = optname; > > > - req.addr = (long __force __user)optval; > > > + req.addr = (__force long)optval; > > > > For casts to integers, even '__force' is not needed (since integers > > can't be dereferenced, the concept of address-space is meaningless > > for them, so it's never useful to warn when it's dropped and > > '__force' is thus not needed). > > That's what I thought. but if I remove it here I actually do get a > warning: > > CHECK net/bpfilter/bpfilter_kern.c > net/bpfilter/bpfilter_kern.c:52:21: warning: cast removes address space '__user' of expression Cast to unsigned long. Or to uintptr_t if you want to be fancy.
