[PATCH 4.14 23/37] Bluetooth: SCO: Replace use of memcpy_from_msg with bt_skb_sendmsg

Greg Kroah-Hartman
2022-07-27T16:27:10Z

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

commit 0771cbb3b97d3c1d68eecd7f00055f599954c34e upstream.

This makes use of bt_skb_sendmsg instead of allocating a different
buffer to be used with memcpy_from_msg which cause one extra copy.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/bluetooth/sco.c | 34 +++++++++++-----------------------
1 file changed, 11 insertions(+), 23 deletions(-)

--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -279,27 +279,19 @@ static int sco_connect(struct hci_dev *h
return err;
}

-static int sco_send_frame(struct sock *sk, void *buf, int len,
- unsigned int msg_flags)
+static int sco_send_frame(struct sock *sk, struct sk_buff *skb)
{
struct sco_conn *conn = sco_pi(sk)->conn;
- struct sk_buff *skb;
- int err;

/* Check outgoing MTU */
- if (len > conn->mtu)
+ if (skb->len > conn->mtu)
return -EINVAL;

- BT_DBG("sk %p len %d", sk, len);
-
- skb = bt_skb_send_alloc(sk, len, msg_flags & MSG_DONTWAIT, &err);
- if (!skb)
- return err;
+ BT_DBG("sk %p len %d", sk, skb->len);

- memcpy(skb_put(skb, len), buf, len);
hci_send_sco(conn->hcon, skb);

- return len;
+ return skb->len;
}

static void sco_recv_frame(struct sco_conn *conn, struct sk_buff *skb)
@@ -716,7 +708,7 @@ static int sco_sock_sendmsg(struct socke
size_t len)
{
struct sock *sk = sock->sk;
- void *buf;
+ struct sk_buff *skb;
int err;

BT_DBG("sock %p, sk %p", sock, sk);
@@ -728,24 +720,20 @@ static int sco_sock_sendmsg(struct socke
if (msg->msg_flags & MSG_OOB)
return -EOPNOTSUPP;

- buf = kmalloc(len, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
-
- if (memcpy_from_msg(buf, msg, len)) {
- kfree(buf);
- return -EFAULT;
- }
+ skb = bt_skb_sendmsg(sk, msg, len, len, 0, 0);
+ if (IS_ERR_OR_NULL(skb))
+ return PTR_ERR(skb);

lock_sock(sk);

if (sk->sk_state == BT_CONNECTED)
- err = sco_send_frame(sk, buf, len, msg->msg_flags);
+ err = sco_send_frame(sk, skb);
else
err = -ENOTCONN;

release_sock(sk);
- kfree(buf);
+ if (err)
+ kfree_skb(skb);
return err;
}