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 <eric.dumazet@gmail.com>
CC: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 @@
/*
* 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 @@
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);
}