From b1042d356305cd183459dea145fd59c0f7491e00 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Wed, 6 Dec 2017 15:03:20 -0800 Subject: [PATCH] netlink: convert netlink tap spinlock to mutex Both netlink_add_tap() and netlink_remove_tap() are called in process context, no need to bother spinlock. Note, in fact, currently we always hold RTNL when calling these two functions, so we don't need any other lock at all, but keeping this lock doesn't harm anything. Cc: Daniel Borkmann Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/netlink/af_netlink.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 1dda94c..b0fe1fb 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -176,7 +176,7 @@ static unsigned int netlink_tap_net_id; struct netlink_tap_net { struct list_head netlink_tap_all; - spinlock_t netlink_tap_lock; + struct mutex netlink_tap_lock; }; int netlink_add_tap(struct netlink_tap *nt) @@ -187,9 +187,9 @@ int netlink_add_tap(struct netlink_tap *nt) if (unlikely(nt->dev->type != ARPHRD_NETLINK)) return -EINVAL; - spin_lock(&nn->netlink_tap_lock); + mutex_lock(&nn->netlink_tap_lock); list_add_rcu(&nt->list, &nn->netlink_tap_all); - spin_unlock(&nn->netlink_tap_lock); + mutex_unlock(&nn->netlink_tap_lock); __module_get(nt->module); @@ -204,7 +204,7 @@ static int __netlink_remove_tap(struct netlink_tap *nt) bool found = false; struct netlink_tap *tmp; - spin_lock(&nn->netlink_tap_lock); + mutex_lock(&nn->netlink_tap_lock); list_for_each_entry(tmp, &nn->netlink_tap_all, list) { if (nt == tmp) { @@ -216,7 +216,7 @@ static int __netlink_remove_tap(struct netlink_tap *nt) pr_warn("__netlink_remove_tap: %p not found\n", nt); out: - spin_unlock(&nn->netlink_tap_lock); + mutex_unlock(&nn->netlink_tap_lock); if (found) module_put(nt->module); @@ -240,7 +240,7 @@ static __net_init int netlink_tap_init_net(struct net *net) struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); INIT_LIST_HEAD(&nn->netlink_tap_all); - spin_lock_init(&nn->netlink_tap_lock); + mutex_init(&nn->netlink_tap_lock); return 0; } -- 2.7.4