From c8406998b80183ef87895ab1de4dbed8bb2d53a0 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 9 Aug 2016 12:16:08 +0200 Subject: [PATCH] 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 Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_state.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c index ac4037cf6a29..53e7867f9254 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 @@ static void xfrm_hash_resize(struct work_struct *work) 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); -- 2.34.1