[PATCH v2 15/17] [atm] switch vcc_sendmsg() to copy_from_iter()

From: Al Viro
Date: Tue Nov 25 2014 - 09:03:09 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

... 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@xxxxxxxxxxxxxxxxxx>
---
net/atm/common.c | 17 ++++++-----------
1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/net/atm/common.c b/net/atm/common.c
index 9cd1cca..f591129 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;
--
1.7.10.4

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