On Fri, Oct 6, 2023 at 10:45 AM Breno Leitao <leitao@xxxxxxxxxx> wrote: > > Hello Jakub, > > On Tue, Sep 05, 2023 at 03:49:51PM -0700, Jakub Kicinski wrote: > > On Mon, 4 Sep 2023 09:24:53 -0700 Breno Leitao wrote: > > > Patches 1-2: Modify the BPF hooks to support sockptr_t, so, these functions > > > become flexible enough to accept user or kernel pointers for optval/optlen. > > > > Have you seen: > > > > https://lore.kernel.org/all/CAHk-=wgGV61xrG=gO0=dXH64o2TDWWrXn1mx-CX885JZ7h84Og@xxxxxxxxxxxxxx/ > > > > ? I wasn't aware that Linus felt this way, now I wonder if having > > sockptr_t spread will raise any red flags as this code flows back > > to him. > > Thanks for the heads-up. I've been thinking about it for a while and I'd > like to hear what are the next steps here. > > 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?
