From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 15 Jul 2009 23:13:10 +0000 (+0000)
Subject: net: sock_copy() fixes
X-Git-Tag: v2.6.31-rc4~11^2~27
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4dc6dc7162c08b9965163c9ab3f9375d4adff2c7;p=pandora-kernel.git

net: sock_copy() fixes

Commit e912b1142be8f1e2c71c71001dc992c6e5eb2ec1
(net: sk_prot_alloc() should not blindly overwrite memory)
took care of not zeroing whole new socket at allocation time.

sock_copy() is another spot where we should be very careful.
We should not set refcnt to a non null value, until
we are sure other fields are correctly setup, or
a lockless reader could catch this socket by mistake,
while not fully (re)initialized.

This patch puts sk_node & sk_refcnt to the very beginning
of struct sock to ease sock_copy() & sk_prot_alloc() job.

We add appropriate smp_wmb() before sk_refcnt initializations
to match our RCU requirements (changes to sock keys should
be committed to memory before sk_refcnt setting)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

Reading git-diff-tree failed