Hi Andrej,
On Wed, Oct 02, 2024 at 04:12:17PM +0200, Andrej Shadura wrote:
> Change the type of len to size_t in both rfcomm_sock_bind and
> rfcomm_sock_getsockopt_old and replace min_t() with min().
rfcomm_sock_bind doesn't use copy_to_user, are you sure it has the same
issue?
> @@ -328,14 +328,15 @@ static int rfcomm_sock_bind(struct socket *sock, struct sockaddr *addr, int addr
> {
> struct sockaddr_rc sa;
> struct sock *sk = sock->sk;
> - int len, err = 0;
> + int err = 0;
> + size_t len;
>
> if (!addr || addr_len < offsetofend(struct sockaddr, sa_family) ||
> addr->sa_family != AF_BLUETOOTH)
> return -EINVAL;
>
> memset(&sa, 0, sizeof(sa));
> - len = min_t(unsigned int, sizeof(sa), addr_len);
> + len = min(sizeof(sa), addr_len);
> memcpy(&sa, addr, len);
>
> BT_DBG("sk %p %pMR", sk, &sa.rc_bdaddr);
This change produces a compilation error around min expression, as
"kernel test robot" notices below. And I think rfcomm_sock_bind
shouldn't be touched at all, it doesn't use copy_to_user and doesn't
produce compile errors with latest Clang.
> @@ -729,7 +730,8 @@ static int rfcomm_sock_getsockopt_old(struct socket *sock, int optname, char __u
> struct sock *l2cap_sk;
> struct l2cap_conn *conn;
> struct rfcomm_conninfo cinfo;
> - int len, err = 0;
> + int err = 0;
> + size_t len;
> u32 opt;
>
> BT_DBG("sk %p", sk);
> @@ -783,7 +785,7 @@ static int rfcomm_sock_getsockopt_old(struct socket *sock, int optname, char __u
> cinfo.hci_handle = conn->hcon->handle;
> memcpy(cinfo.dev_class, conn->hcon->dev_class, 3);
>
> - len = min_t(unsigned int, len, sizeof(cinfo));
> + len = min(len, sizeof(cinfo));
> if (copy_to_user(optval, (char *) &cinfo, len))
> err = -EFAULT;
>
This looks ok. But there is the same pattern in rfcomm_sock_getsockopt
(without old prefix) and it also uses copy_to_user and produces compile
error with latest Clang.
Could you remove rfcomm_sock_bind patch and apply it to
rfcomm_sock_getsockopt instead? Or I can send my version of the patch:
we've encountered the same compile errors in rfcomm_sock_getsockopt and
rfcomm_sock_getsockopt_old after updating Clang and would like to get it
fixed.
