net: Remove all uses of LL_ALLOCATED_SPACE

net: Remove all uses of LL_ALLOCATED_SPACE

The macro LL_ALLOCATED_SPACE was ill-conceived.  It applies the
alignment to the sum of needed_headroom and needed_tailroom.  As
the amount that is then reserved for head room is needed_headroom
with alignment, this means that the tail room left may be too small.

This patch replaces all uses of LL_ALLOCATED_SPACE with the macro
LL_RESERVED_SPACE and direct reference to needed_tailroom.

This also fixes the problem with needed_headroom changing between
allocating the skb and reserving the head room.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 2 deletions

diff --git a/net/ieee802154/dgram.c b/net/ieee802154/dgram.c
index faecf648123f..1b09eaabaac1 100644
--- a/net/ieee802154/dgram.c
+++ b/net/ieee802154/dgram.c
@@ -209,6 +209,7 @@ static int dgram_sendmsg(struct kiocb *iocb, struct sock *sk,
         unsigned mtu;
         struct sk_buff *skb;
         struct dgram_sock *ro = dgram_sk(sk);
+        int hlen, tlen;
         int err;
 
         if (msg->msg_flags & MSG_OOB) {
@@ -229,13 +230,15 @@ static int dgram_sendmsg(struct kiocb *iocb, struct sock *sk,
         mtu = dev->mtu;
         pr_debug("name = %s, mtu = %u\n", dev->name, mtu);
 
-        skb = sock_alloc_send_skb(sk, LL_ALLOCATED_SPACE(dev) + size,
+        hlen = LL_RESERVED_SPACE(dev);
+        tlen = dev->needed_tailroom;
+        skb = sock_alloc_send_skb(sk, hlen + tlen + size,
                         msg->msg_flags & MSG_DONTWAIT,
                         &err);
         if (!skb)
                 goto out_dev;
 
-        skb_reserve(skb, LL_RESERVED_SPACE(dev));
+        skb_reserve(skb, hlen);
 
         skb_reset_network_header(skb);