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Eric Dumazet ef8531b64c xfrm: fix RCU bugs

This patch reverts commit 56892261ed1a (xfrm: Use rcu_dereference_bh to
deference pointer protected by rcu_read_lock_bh), and fixes bugs
introduced in commit 418a99ac6ad ( Replace rwlock on xfrm_policy_afinfo
with rcu )

1) We properly use RCU variant in this file, not a mix of RCU/RCU_BH

2) We must defer some writes after the synchronize_rcu() call or a reader
 can crash dereferencing NULL pointer.

3) Now we use the xfrm_policy_afinfo_lock spinlock only from process
context, we no longer need to block BH in xfrm_policy_register_afinfo()
and xfrm_policy_unregister_afinfo()

4) Can use RCU_INIT_POINTER() instead of rcu_assign_pointer() in
xfrm_policy_unregister_afinfo()

5) Remove a forward inline declaration (xfrm_policy_put_afinfo()),
  and also move xfrm_policy_get_afinfo() declaration.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Fan Du <fan.du@windriver.com>
Cc: Priyanka Jain <Priyanka.Jain@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2012-08-22 22:39:46 -07:00

Kconfig

xfrm: make xfrm_algo.c a module

2012-05-15 13:13:34 -04:00

Makefile

xfrm: make xfrm_algo.c a module

2012-05-15 13:13:34 -04:00

xfrm_algo.c

xfrm_algo: drop an unnecessary inclusion

2012-05-15 13:13:34 -04:00

xfrm_hash.c

net: allow GFP_HIGHMEM in __vmalloc()