xfrm: state: use rcu_deref and assign_pointer helpers
Before xfrm_state_find() can use rcu_read_lock instead of xfrm_state_lock
we need to switch users of the hash table to assign/obtain the pointers
with the appropriate rcu helpers.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index ac4037c..53e7867 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -28,6 +28,9 @@
#include "xfrm_hash.h"
+#define xfrm_state_deref_prot(table, net) \
+ rcu_dereference_protected((table), lockdep_is_held(&(net)->xfrm.xfrm_state_lock))
+
/* Each xfrm_state may be linked to two tables:
1. Hash table by (spi,daddr,ah/esp) to find SA by SPI. (input,ctl)
@@ -131,18 +134,17 @@
write_seqcount_begin(&xfrm_state_hash_generation);
nhashmask = (nsize / sizeof(struct hlist_head)) - 1U;
+ odst = xfrm_state_deref_prot(net->xfrm.state_bydst, net);
for (i = net->xfrm.state_hmask; i >= 0; i--)
- xfrm_hash_transfer(net->xfrm.state_bydst+i, ndst, nsrc, nspi,
- nhashmask);
+ xfrm_hash_transfer(odst + i, ndst, nsrc, nspi, nhashmask);
- odst = net->xfrm.state_bydst;
- osrc = net->xfrm.state_bysrc;
- ospi = net->xfrm.state_byspi;
+ osrc = xfrm_state_deref_prot(net->xfrm.state_bysrc, net);
+ ospi = xfrm_state_deref_prot(net->xfrm.state_byspi, net);
ohashmask = net->xfrm.state_hmask;
- net->xfrm.state_bydst = ndst;
- net->xfrm.state_bysrc = nsrc;
- net->xfrm.state_byspi = nspi;
+ rcu_assign_pointer(net->xfrm.state_bydst, ndst);
+ rcu_assign_pointer(net->xfrm.state_bysrc, nsrc);
+ rcu_assign_pointer(net->xfrm.state_byspi, nspi);
net->xfrm.state_hmask = nhashmask;
write_seqcount_end(&xfrm_state_hash_generation);
