[PATCH] namespaces: utsname: switch to using uts namespaces

Replace references to system_utsname to the per-process uts namespace
where appropriate.  This includes things like uname.

Changes: Per Eric Biederman's comments, use the per-process uts namespace
	for ELF_PLATFORM, sunrpc, and parts of net/ipv4/ipconfig.c

[jdike@addtoit.com: UML fix]
[clg@fr.ibm.com: cleanup]
[akpm@osdl.org: build fix]
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Andrey Savochkin <saw@sw.ru>
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/sys.c b/kernel/sys.c
index 398d579..3a4776e 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1655,7 +1655,7 @@
 	int errno = 0;
 
 	down_read(&uts_sem);
-	if (copy_to_user(name,&system_utsname,sizeof *name))
+	if (copy_to_user(name, utsname(), sizeof *name))
 		errno = -EFAULT;
 	up_read(&uts_sem);
 	return errno;
@@ -1673,8 +1673,8 @@
 	down_write(&uts_sem);
 	errno = -EFAULT;
 	if (!copy_from_user(tmp, name, len)) {
-		memcpy(system_utsname.nodename, tmp, len);
-		system_utsname.nodename[len] = 0;
+		memcpy(utsname()->nodename, tmp, len);
+		utsname()->nodename[len] = 0;
 		errno = 0;
 	}
 	up_write(&uts_sem);
@@ -1690,11 +1690,11 @@
 	if (len < 0)
 		return -EINVAL;
 	down_read(&uts_sem);
-	i = 1 + strlen(system_utsname.nodename);
+	i = 1 + strlen(utsname()->nodename);
 	if (i > len)
 		i = len;
 	errno = 0;
-	if (copy_to_user(name, system_utsname.nodename, i))
+	if (copy_to_user(name, utsname()->nodename, i))
 		errno = -EFAULT;
 	up_read(&uts_sem);
 	return errno;
@@ -1719,8 +1719,8 @@
 	down_write(&uts_sem);
 	errno = -EFAULT;
 	if (!copy_from_user(tmp, name, len)) {
-		memcpy(system_utsname.domainname, tmp, len);
-		system_utsname.domainname[len] = 0;
+		memcpy(utsname()->domainname, tmp, len);
+		utsname()->domainname[len] = 0;
 		errno = 0;
 	}
 	up_write(&uts_sem);