From 49e8ab03ebcacd8e37660ffec20c0c46721a2800 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 19 Aug 2010 06:10:45 +0000 Subject: [PATCH] net: build_ehash_secret() and rt_bind_peer() cleanups Now cmpxchg() is available on all arches, we can use it in build_ehash_secret() and rt_bind_peer() instead of using spinlocks. Signed-off-by: Eric Dumazet CC: Mathieu Desnoyers Signed-off-by: David S. Miller --- net/ipv4/af_inet.c | 8 +++----- net/ipv4/route.c | 9 +-------- 2 files changed, 4 insertions(+), 13 deletions(-) diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 6a1100c..f581f77 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -227,18 +227,16 @@ EXPORT_SYMBOL(inet_ehash_secret); /* * inet_ehash_secret must be set exactly once - * Instead of using a dedicated spinlock, we (ab)use inetsw_lock */ void build_ehash_secret(void) { u32 rnd; + do { get_random_bytes(&rnd, sizeof(rnd)); } while (rnd == 0); - spin_lock_bh(&inetsw_lock); - if (!inet_ehash_secret) - inet_ehash_secret = rnd; - spin_unlock_bh(&inetsw_lock); + + cmpxchg(&inet_ehash_secret, 0, rnd); } EXPORT_SYMBOL(build_ehash_secret); diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 3f56b6e..85a67c9 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1268,18 +1268,11 @@ skip_hashing: void rt_bind_peer(struct rtable *rt, int create) { - static DEFINE_SPINLOCK(rt_peer_lock); struct inet_peer *peer; peer = inet_getpeer(rt->rt_dst, create); - spin_lock_bh(&rt_peer_lock); - if (rt->peer == NULL) { - rt->peer = peer; - peer = NULL; - } - spin_unlock_bh(&rt_peer_lock); - if (peer) + if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL) inet_putpeer(peer); } -- 2.7.4