CRED: Separate task security context from task_struct

Separate the task security context from task_struct.  At this point, the
security data is temporarily embedded in the task_struct with two pointers
pointing to it.

Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in
entry.S via asm-offsets.

With comment fixes Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com>

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S
index 5fc61e2..f77345b 100644
--- a/arch/alpha/kernel/entry.S
+++ b/arch/alpha/kernel/entry.S
@@ -850,8 +850,9 @@
 sys_getxuid:
 	.prologue 0
 	ldq	$2, TI_TASK($8)
-	ldl	$0, TASK_UID($2)
-	ldl	$1, TASK_EUID($2)
+	ldq	$3, TASK_CRED($2)
+	ldl	$0, CRED_UID($3)
+	ldl	$1, CRED_EUID($3)
 	stq	$1, 80($sp)
 	ret
 .end sys_getxuid
@@ -862,8 +863,9 @@
 sys_getxgid:
 	.prologue 0
 	ldq	$2, TI_TASK($8)
-	ldl	$0, TASK_GID($2)
-	ldl	$1, TASK_EGID($2)
+	ldq	$3, TASK_CRED($2)
+	ldl	$0, CRED_GID($3)
+	ldl	$1, CRED_EGID($3)
 	stq	$1, 80($sp)
 	ret
 .end sys_getxgid