[atm] switch vcc_sendmsg() to copy_from_iter()

... and make it handle multi-segment iovecs - deals with that
"fix this later" issue for free.  A bit of shame, really - it
had been there since 2.3.15pre3 when the whole thing went into the
tree, practically a historical artefact by now...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 6 insertions, 11 deletions

diff --git a/net/atm/common.c b/net/atm/common.c
index 9cd1ccae9a11..f59112944c91 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -570,15 +570,16 @@ int vcc_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 }
 
 int vcc_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
-                size_t total_len)
+                size_t size)
 {
         struct sock *sk = sock->sk;
         DEFINE_WAIT(wait);
         struct atm_vcc *vcc;
         struct sk_buff *skb;
         int eff, error;
-        const void __user *buff;
-        int size;
+        struct iov_iter from;
+
+        iov_iter_init(&from, WRITE, m->msg_iov, m->msg_iovlen, size);
 
         lock_sock(sk);
         if (sock->state != SS_CONNECTED) {
@@ -589,12 +590,6 @@ int vcc_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
                 error = -EISCONN;
                 goto out;
         }
-        if (m->msg_iovlen != 1) {
-                error = -ENOSYS; /* fix this later @@@ */
-                goto out;
-        }
-        buff = m->msg_iov->iov_base;
-        size = m->msg_iov->iov_len;
         vcc = ATM_SD(sock);
         if (test_bit(ATM_VF_RELEASED, &vcc->flags) ||
             test_bit(ATM_VF_CLOSE, &vcc->flags) ||
@@ -607,7 +602,7 @@ int vcc_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
                 error = 0;
                 goto out;
         }
-        if (size < 0 || size > vcc->qos.txtp.max_sdu) {
+        if (size > vcc->qos.txtp.max_sdu) {
                 error = -EMSGSIZE;
                 goto out;
         }
@@ -639,7 +634,7 @@ int vcc_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
                 goto out;
         skb->dev = NULL; /* for paths shared with net_device interfaces */
         ATM_SKB(skb)->atm_options = vcc->atm_options;
-        if (copy_from_user(skb_put(skb, size), buff, size)) {
+        if (copy_from_iter(skb_put(skb, size), size, &from) != size) {
                 kfree_skb(skb);
                 error = -EFAULT;
                 goto out;