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 Using this recent sparse build: hch@brick:~/work/linux$ sparse --version v0.6.2-49-g707c5017
