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authorEric W. Biederman <ebiederm@xmission.com>2009-12-13 22:39:28 -0800
committerGreg Kroah-Hartman <gregkh@suse.de>2009-12-18 14:05:38 -0800
commitad496b34c6835a89dd3a8f6c07dfcf8a0dd7c277 (patch)
tree11ea467997f677454fa4ddf54e7632c2d522b781
parent383073d49fc78aa793c51018e29253c83410401e (diff)
downloadlwn-ad496b34c6835a89dd3a8f6c07dfcf8a0dd7c277.tar.gz
lwn-ad496b34c6835a89dd3a8f6c07dfcf8a0dd7c277.zip
net: Fix userspace RTM_NEWLINK notifications.
commit d90a909e1f3e006a1d57fe11fd417173b6494701 upstream. I received some bug reports about userspace programs having problems because after RTM_NEWLINK was received they could not immeidate access files under /proc/sys/net/ because they had not been registered yet. The problem was trivailly fixed by moving the userspace notification from rtnetlink_event to the end of register_netdevice. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--net/core/dev.c11
-rw-r--r--net/core/rtnetlink.c4
2 files changed, 12 insertions, 3 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index fe10551d3671..584046eef9cb 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4860,6 +4860,11 @@ int register_netdevice(struct net_device *dev)
rollback_registered(dev);
dev->reg_state = NETREG_UNREGISTERED;
}
+ /*
+ * Prevent userspace races by waiting until the network
+ * device is fully setup before sending notifications.
+ */
+ rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
out:
return ret;
@@ -5398,6 +5403,12 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
/* Notify protocols, that a new device appeared. */
call_netdevice_notifiers(NETDEV_REGISTER, dev);
+ /*
+ * Prevent userspace races by waiting until the network
+ * device is fully setup before sending notifications.
+ */
+ rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
+
synchronize_net();
err = 0;
out:
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index eb42873f2a3a..d4fd895e8712 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1334,13 +1334,11 @@ static int rtnetlink_event(struct notifier_block *this, unsigned long event, voi
case NETDEV_UNREGISTER:
rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
break;
- case NETDEV_REGISTER:
- rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
- break;
case NETDEV_UP:
case NETDEV_DOWN:
rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
break;
+ case NETDEV_REGISTER:
case NETDEV_CHANGE:
case NETDEV_GOING_DOWN:
break;