[PATCH] uevent: send events in correct order according to seqnum

[Andrew Vagin]

The queue handling in the udev daemon assumes that the events are
ordered.

Before this patch uevent_seqnum is incremented under sequence_lock,
than an event is send uner uevent_sock_mutex. I want to say that code
contained a window between incrementing seqnum and sending an event.

This patch locks uevent_sock_mutex before incrementing uevent_seqnum.

Signed-off-by: Andrew Vagin <avagin@xxxxxxxxxx>
---
 lib/kobject_uevent.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index e66e9b6..596c40d 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -243,6 +243,9 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 	else if (action == KOBJ_REMOVE)
 		kobj->state_remove_uevent_sent = 1;
 
+#if defined(CONFIG_NET)
+	mutex_lock(&uevent_sock_mutex);
+#endif
 	/* we will send an event, so request a new sequence number */
 	spin_lock(&sequence_lock);
 	seq = ++uevent_seqnum;
@@ -253,7 +256,6 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 
 #if defined(CONFIG_NET)
 	/* send netlink message */
-	mutex_lock(&uevent_sock_mutex);
 	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
 		struct sock *uevent_sock = ue_sk->sk;
 		struct sk_buff *skb;