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tcp: Always set options to 0 before calling tcp_established_options 

tcp_established_options assumes opts->options is 0 before calling,
as it read modify writes it.

For the tcp_current_mss() case the opts structure is not zeroed,
so this can be done with uninitialized values.

This is ok, because ->options is not read in this path.
But it's still better to avoid the operation on the uninitialized
field. This shuts up a static code analyzer, and presumably
may help the optimizer.

Cc: netdev@vger.kernel.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Andi Kleen 2013-09-30 13:29:11 -07:00 committed by David S. Miller
parent 58e4e1f6ca
commit 5843ef4213
1 changed files with 2 additions and 0 deletions
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2
net/ipv4/tcp_output.c
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@ -637,6 +637,8 @@ static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb
unsigned int size = 0;
unsigned int eff_sacks;
opts->options = 0;
#ifdef CONFIG_TCP_MD5SIG
*md5 = tp->af_specific->md5_lookup(sk, sk);
if (unlikely(*md5)) {