Isolate the UTS namespace's domainname and hostname back

The commit

commit 7d69a1f4a72b18876c99c697692b78339d491568

Author: Cedric Le Goater <[email protected]>
Date:   Sun Jul 15 23:40:58 2007 -0700

remove CONFIG_UTS_NS and CONFIG_IPC_NS

accidentally removed the code, that prevented the uts->hostname and uts->domainname values from being overwritten from another namespace. In other words, setting hostname/domainname via sysfs (echo xxx > /proc/sys/kernel/(host|domain)name) cased the new value to be set in init UTS namespace only.

Return the isolation back.

---

index c76c064..fe3a56c 100644
@@ -18,6 +18,10 @@
 static void *get_uts(ctl_table *table, int write)
 {
 	char *which = table->data;
+	struct uts_namespace *uts_ns;
+
+	uts_ns = current->nsproxy->uts_ns;
+	which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
 
 	if (!write)
 		down_read(&uts_sem);

yep. sorry about that. I was going to send the same patch in a minute.

Thanks,

C.