diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-04-21 09:45:37 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-04-28 13:16:35 -0700 |
| commit | f6d8bd051c391c1c0458a30b2a7abcd939329259 (patch) | |
| tree | 1dc4daecdeb0b42c2c6b59d7d6b41e091c11db5f /include/net/inet_sock.h | |
| parent | 0a14842f5a3c0e88a1e59fac5c3025db39721f74 (diff) | |
inet: add RCU protection to inet->opt
We lack proper synchronization to manipulate inet->opt ip_options
Problem is ip_make_skb() calls ip_setup_cork() and
ip_setup_cork() possibly makes a copy of ipc->opt (struct ip_options),
without any protection against another thread manipulating inet->opt.
Another thread can change inet->opt pointer and free old one under us.
Use RCU to protect inet->opt (changed to inet->inet_opt).
Instead of handling atomic refcounts, just copy ip_options when
necessary, to avoid cache line dirtying.
We cant insert an rcu_head in struct ip_options since its included in
skb->cb[], so this patch is large because I had to introduce a new
ip_options_rcu structure.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/inet_sock.h')
| -rw-r--r-- | include/net/inet_sock.h | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h index 7a37369f8ea..ed2ba6eca72 100644 --- a/include/net/inet_sock.h +++ b/include/net/inet_sock.h @@ -57,7 +57,15 @@ struct ip_options { unsigned char __data[0]; }; -#define optlength(opt) (sizeof(struct ip_options) + opt->optlen) +struct ip_options_rcu { + struct rcu_head rcu; + struct ip_options opt; +}; + +struct ip_options_data { + struct ip_options_rcu opt; + char data[40]; +}; struct inet_request_sock { struct request_sock req; @@ -78,7 +86,7 @@ struct inet_request_sock { acked : 1, no_srccheck: 1; kmemcheck_bitfield_end(flags); - struct ip_options *opt; + struct ip_options_rcu *opt; }; static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk) @@ -140,7 +148,7 @@ struct inet_sock { __be16 inet_sport; __u16 inet_id; - struct ip_options *opt; + struct ip_options_rcu __rcu *inet_opt; __u8 tos; __u8 min_ttl; __u8 mc_ttl; |