userns: Convert the audit loginuid  to be a kuid

Always store audit loginuids in type kuid_t.

Print loginuids by converting them into uids in the appropriate user
namespace, and then printing the resulting uid.

Modify audit_get_loginuid to return a kuid_t.

Modify audit_set_loginuid to take a kuid_t.

Modify /proc/<pid>/loginuid on read to convert the loginuid into the
user namespace of the opener of the file.

Modify /proc/<pid>/loginud on write to convert the loginuid
rom the user namespace of the opener of the file.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Paul Moore <paul@paul-moore.com> ?
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index c5a5165..2f47515 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -2630,12 +2630,12 @@
 
 	flush_work(&net->xfrm.policy_hash_work);
 #ifdef CONFIG_XFRM_SUB_POLICY
-	audit_info.loginuid = -1;
+	audit_info.loginuid = INVALID_UID;
 	audit_info.sessionid = -1;
 	audit_info.secid = 0;
 	xfrm_policy_flush(net, XFRM_POLICY_TYPE_SUB, &audit_info);
 #endif
-	audit_info.loginuid = -1;
+	audit_info.loginuid = INVALID_UID;
 	audit_info.sessionid = -1;
 	audit_info.secid = 0;
 	xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, &audit_info);
@@ -2742,7 +2742,7 @@
 }
 
 void xfrm_audit_policy_add(struct xfrm_policy *xp, int result,
-			   uid_t auid, u32 sessionid, u32 secid)
+			   kuid_t auid, u32 sessionid, u32 secid)
 {
 	struct audit_buffer *audit_buf;
 
@@ -2757,7 +2757,7 @@
 EXPORT_SYMBOL_GPL(xfrm_audit_policy_add);
 
 void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result,
-			      uid_t auid, u32 sessionid, u32 secid)
+			      kuid_t auid, u32 sessionid, u32 secid)
 {
 	struct audit_buffer *audit_buf;
 
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 5b228f9..fce6a49 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2045,7 +2045,7 @@
 	unsigned int sz;
 
 	flush_work(&net->xfrm.state_hash_work);
-	audit_info.loginuid = -1;
+	audit_info.loginuid = INVALID_UID;
 	audit_info.sessionid = -1;
 	audit_info.secid = 0;
 	xfrm_state_flush(net, IPSEC_PROTO_ANY, &audit_info);
@@ -2112,7 +2112,7 @@
 }
 
 void xfrm_audit_state_add(struct xfrm_state *x, int result,
-			  uid_t auid, u32 sessionid, u32 secid)
+			  kuid_t auid, u32 sessionid, u32 secid)
 {
 	struct audit_buffer *audit_buf;
 
@@ -2127,7 +2127,7 @@
 EXPORT_SYMBOL_GPL(xfrm_audit_state_add);
 
 void xfrm_audit_state_delete(struct xfrm_state *x, int result,
-			     uid_t auid, u32 sessionid, u32 secid)
+			     kuid_t auid, u32 sessionid, u32 secid)
 {
 	struct audit_buffer *audit_buf;
 
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index e75d8e4..9ea55db 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -575,7 +575,7 @@
 	struct xfrm_state *x;
 	int err;
 	struct km_event c;
-	uid_t loginuid = audit_get_loginuid(current);
+	kuid_t loginuid = audit_get_loginuid(current);
 	u32 sessionid = audit_get_sessionid(current);
 	u32 sid;
 
@@ -654,7 +654,7 @@
 	int err = -ESRCH;
 	struct km_event c;
 	struct xfrm_usersa_id *p = nlmsg_data(nlh);
-	uid_t loginuid = audit_get_loginuid(current);
+	kuid_t loginuid = audit_get_loginuid(current);
 	u32 sessionid = audit_get_sessionid(current);
 	u32 sid;
 
@@ -1369,7 +1369,7 @@
 	struct km_event c;
 	int err;
 	int excl;
-	uid_t loginuid = audit_get_loginuid(current);
+	kuid_t loginuid = audit_get_loginuid(current);
 	u32 sessionid = audit_get_sessionid(current);
 	u32 sid;
 
@@ -1624,7 +1624,7 @@
 					    NETLINK_CB(skb).pid);
 		}
 	} else {
-		uid_t loginuid = audit_get_loginuid(current);
+		kuid_t loginuid = audit_get_loginuid(current);
 		u32 sessionid = audit_get_sessionid(current);
 		u32 sid;
 
@@ -1918,7 +1918,7 @@
 
 	err = 0;
 	if (up->hard) {
-		uid_t loginuid = audit_get_loginuid(current);
+		kuid_t loginuid = audit_get_loginuid(current);
 		u32 sessionid = audit_get_sessionid(current);
 		u32 sid;
 
@@ -1961,7 +1961,7 @@
 	km_state_expired(x, ue->hard, current->pid);
 
 	if (ue->hard) {
-		uid_t loginuid = audit_get_loginuid(current);
+		kuid_t loginuid = audit_get_loginuid(current);
 		u32 sessionid = audit_get_sessionid(current);
 		u32 sid;