net caif: Register properly as a pernet subsystem.

[ Upstream commit 8a8ee9aff6c3077dd9c2c7a77478e8ed362b96c6 ]

caif is a subsystem and as such it needs to register with
register_pernet_subsys instead of register_pernet_device.

Among other problems using register_pernet_device was resulting in
net_generic being called before the caif_net structure was allocated.
Which has been causing net_generic to fail with either BUG_ON's or by
return NULL pointers.

A more ugly problem that could be caused is packets in flight why the
subsystem is shutting down.

To remove confusion also remove the cruft cause by inappropriately
trying to fix this bug.

With the aid of the previous patch I have tested this patch and
confirmed that using register_pernet_subsys makes the failure go away as
it should.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Tested-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/caif/caif_dev.c b/net/caif/caif_dev.c
index f1fa1f6e658d4dc84ca6eea2abceb6be6d3e8283..68223e4c4bf0d6a7bfb020ac8cef99a23f983336 100644 (file)
--- a/net/caif/caif_dev.c
+++ b/net/caif/caif_dev.c
@@ -53,7 +53,6 @@ struct cfcnfg *get_cfcnfg(struct net *net)
        struct caif_net *caifn;
        BUG_ON(!net);
        caifn = net_generic(net, caif_net_id);
-       BUG_ON(!caifn);
        return caifn->cfg;
 }
 EXPORT_SYMBOL(get_cfcnfg);
@@ -63,7 +62,6 @@ static struct caif_device_entry_list *caif_device_list(struct net *net)
        struct caif_net *caifn;
        BUG_ON(!net);
        caifn = net_generic(net, caif_net_id);
-       BUG_ON(!caifn);
        return &caifn->caifdevs;
 }
 
@@ -92,7 +90,6 @@ static struct caif_device_entry *caif_device_alloc(struct net_device *dev)
        struct caif_device_entry *caifd;
 
        caifdevs = caif_device_list(dev_net(dev));
-       BUG_ON(!caifdevs);
 
        caifd = kzalloc(sizeof(*caifd), GFP_KERNEL);
        if (!caifd)
@@ -112,7 +109,7 @@ static struct caif_device_entry *caif_get(struct net_device *dev)
        struct caif_device_entry_list *caifdevs =
            caif_device_list(dev_net(dev));
        struct caif_device_entry *caifd;
-       BUG_ON(!caifdevs);
+
        list_for_each_entry_rcu(caifd, &caifdevs->list, list) {
                if (caifd->netdev == dev)
                        return caifd;
@@ -353,7 +350,7 @@ static struct notifier_block caif_device_notifier = {
 static int caif_init_net(struct net *net)
 {
        struct caif_net *caifn = net_generic(net, caif_net_id);
-       BUG_ON(!caifn);
+
        INIT_LIST_HEAD(&caifn->caifdevs.list);
        mutex_init(&caifn->caifdevs.lock);
 
@@ -418,7 +415,7 @@ static int __init caif_device_init(void)
 {
        int result;
 
-       result = register_pernet_device(&caif_net_ops);
+       result = register_pernet_subsys(&caif_net_ops);
 
        if (result)
                return result;
@@ -431,7 +428,7 @@ static int __init caif_device_init(void)
 
 static void __exit caif_device_exit(void)
 {
-       unregister_pernet_device(&caif_net_ops);
+       unregister_pernet_subsys(&caif_net_ops);
        unregister_netdevice_notifier(&caif_device_notifier);
        dev_remove_pack(&caif_packet_type);
 }

diff --git a/net/caif/cfcnfg.c b/net/caif/cfcnfg.c
index 00523ecc4ced75ebaa1059c1eb3e0a324cae182e..86ff37c65946af271521c58c69ee40095730c56f 100644 (file)
--- a/net/caif/cfcnfg.c
+++ b/net/caif/cfcnfg.c
@@ -309,7 +309,6 @@ int caif_connect_client(struct net *net, struct caif_connect_request *conn_req,
        int err;
        struct cfctrl_link_param param;
        struct cfcnfg *cfg = get_cfcnfg(net);
-       caif_assert(cfg != NULL);
 
        rcu_read_lock();
        err = caif_connect_req_to_link_param(cfg, conn_req, &param);