io_uring/net: unify *mshot_prep calls with compat

Instead of duplicating a io_recvmsg_mshot_prep() call in the compat
path, let the common code handle it. For that, copy necessary compat
fields into struct user_msghdr. Note, it zeroes user_msghdr to be on the
safe side as compat is not that interesting and overhead shouldn't be
high.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/94e62386dec570f83b4a4270a46ac60bc415fb71.1740569495.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/net.c b/io_uring/net.c
index 36e218b62319c28666a604668b0cbb0ae7e49801..efa2d901762f55d038ec3310036071fcd5ecf582 100644 (file)
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -714,20 +714,20 @@ static int io_recvmsg_copy_hdr(struct io_kiocb *req,
        iomsg->msg.msg_name = &iomsg->addr;
        iomsg->msg.msg_iter.nr_segs = 0;
 
-#ifdef CONFIG_COMPAT
        if (io_is_compat(req->ctx)) {
+#ifdef CONFIG_COMPAT
                struct compat_msghdr cmsg;
 
                ret = io_compat_msg_copy_hdr(req, iomsg, &cmsg, ITER_DEST,
                                             &iomsg->uaddr);
-               if (unlikely(ret))
-                       return ret;
-               return io_recvmsg_mshot_prep(req, iomsg, cmsg.msg_namelen,
-                                               cmsg.msg_controllen);
-       }
+               memset(&msg, 0, sizeof(msg));
+               msg.msg_namelen = cmsg.msg_namelen;
+               msg.msg_controllen = cmsg.msg_controllen;
 #endif
+       } else {
+               ret = io_msg_copy_hdr(req, iomsg, &msg, ITER_DEST, &iomsg->uaddr);
+       }
 
-       ret = io_msg_copy_hdr(req, iomsg, &msg, ITER_DEST, &iomsg->uaddr);
        if (unlikely(ret))
                return ret;
        return io_recvmsg_mshot_prep(req, iomsg, msg.msg_namelen,