io_uring: refactor compat_msghdr import

Add an entry for user pointer to compat_msghdr into io_connect, so it's
explicit that we may use it as this, and removes annoying casts.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/73fd644dea1518f528d3648981cf777ce6e537e9.1618101759.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 9aaf323..1779306 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -570,8 +570,9 @@ struct io_connect {
 struct io_sr_msg {
        struct file                     *file;
        union {
-               struct user_msghdr __user *umsg;
-               void __user             *buf;
+               struct compat_msghdr __user     *umsg_compat;
+               struct user_msghdr __user       *umsg;
+               void __user                     *buf;
        };
        int                             msg_flags;
        int                             bgid;
@@ -4435,16 +4436,14 @@ static int __io_recvmsg_copy_hdr(struct io_kiocb *req,
 static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
                                        struct io_async_msghdr *iomsg)
 {
-       struct compat_msghdr __user *msg_compat;
        struct io_sr_msg *sr = &req->sr_msg;
        struct compat_iovec __user *uiov;
        compat_uptr_t ptr;
        compat_size_t len;
        int ret;
 
-       msg_compat = (struct compat_msghdr __user *) sr->umsg;
-       ret = __get_compat_msghdr(&iomsg->msg, msg_compat, &iomsg->uaddr,
-                                       &ptr, &len);
+       ret = __get_compat_msghdr(&iomsg->msg, sr->umsg_compat, &iomsg->uaddr,
+                                 &ptr, &len);
        if (ret)
                return ret;