diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-09-19 23:39:12 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-09-21 00:23:00 -0400 |
| commit | b2d3ea4a730f812b9c0f67a67b6762ce66ddb17c (patch) | |
| tree | 3d854b9e251be86efe1d816201163f8f33c0c4b5 /net | |
| parent | 77879147a3481babffd7e368d977ab682545a6bd (diff) | |
tcp: switch back to proper tcp_skb_cb size check in tcp_init()
Revert to the tcp_skb_cb size check that tcp_init() had before commit
b4772ef879a8 ("net: use common macro for assering skb->cb[] available
size in protocol families"). As related commit 744d5a3e9fe2 ("net:
move skb->dropcount to skb->cb[]") explains, the
sock_skb_cb_check_size() mechanism was added to ensure that there is
space for dropcount, "for protocol families using it". But TCP is not
a protocol using dropcount, so tcp_init() doesn't need to provision
space for dropcount in the skb->cb[], and thus we can revert to the
older form of the tcp_skb_cb size check. Doing so allows TCP to use 4
more bytes of the skb->cb[] space.
Fixes: b4772ef879a8 ("net: use common macro for assering skb->cb[] available size in protocol families")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index e79ed17ccfd6..de02fb4b1349 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3261,11 +3261,12 @@ static void __init tcp_init_mem(void) void __init tcp_init(void) { - unsigned long limit; int max_rshare, max_wshare, cnt; + unsigned long limit; unsigned int i; - sock_skb_cb_check_size(sizeof(struct tcp_skb_cb)); + BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > + FIELD_SIZEOF(struct sk_buff, cb)); percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL); percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL); |