On Mon, Oct 09, 2023 at 03:11:05AM -0700, Willem de Bruijn wrote: > On Fri, Oct 6, 2023 at 10:45 AM Breno Leitao <leitao@xxxxxxxxxx> wrote: > > Let me first back up and state where we are, and what is the current > > situation: > > > > 1) __sys_getsockopt() uses __user pointers for both optval and optlen > > 2) For io_uring command, Jens[1] suggested we get optlen from the io_uring > > sqe, which is a kernel pointer/value. > > > > Thus, we need to make the common code (callbacks) able to handle __user > > and kernel pointers (for optlen, at least). > > > > From a proto_ops callback perspective, ->setsockopt() uses sockptr. > > > > int (*setsockopt)(struct socket *sock, int level, > > int optname, sockptr_t optval, > > unsigned int optlen); > > > > Getsockopt() uses sockptr() for level=SOL_SOCKET: > > > > int sk_getsockopt(struct sock *sk, int level, int optname, > > sockptr_t optval, sockptr_t optlen) > > > > But not for the other levels: > > > > int (*getsockopt)(struct socket *sock, int level, > > int optname, char __user *optval, int __user *optlen); > > > > > > That said, if this patchset shouldn't use sockptr anymore, what is the > > recommendation? > > > > If we move this patchset to use iov_iter instead of sockptr, then I > > understand we want to move *all* these callbacks to use iov_vec. Is this > > the right direction? > > > > Thanks for the guidance! > > > > [1] https://lore.kernel.org/all/efe602f1-8e72-466c-b796-0083fd1c6d82@xxxxxxxxx/ > > Since sockptr_t is already used by __sys_setsockopt and > __sys_setsockopt, patches 1 and 2 don't introduce any new sockptr code > paths. > > setsockopt callbacks also already use sockptr as of commit > a7b75c5a8c41 ("net: pass a sockptr_t into ->setsockopt"). > > getsockopt callbacks do take user pointers, just not sockptr. > > Is the only issue right now the optlen kernel pointer? Correct. The current discussion is only related to optlen in the getsockopt() callbacks (invoked when level != SOL_SOCKET). Everything else (getsockopt(level=SOL_SOCKET..) and setsockopt) is using sockptr. Is it bad if we review/merge this code as is (using sockptr), and start the iov_iter/getsockopt() refactor in a follow-up thread? Thanks!
