[PATCH] SELinux: add task_movememory hook

This patch adds new security hook, task_movememory, to be called when memory
owened by a task is to be moved (e.g.  when migrating pages to a this hook is
identical to the setscheduler implementation, but a separate hook introduced
to allow this check to be specialized in the future if necessary.

Since the last posting, the hook has been renamed following feedback from
Christoph Lameter.

Signed-off-by: David Quigley <dpquigl@tycho.nsa.gov>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@muc.de>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/security.h b/include/linux/security.h
index 65b32a0..d2c17bd 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -601,6 +601,10 @@
  *	@p.
  *	@p contains the task_struct for process.
  *	Return 0 if permission is granted.
+ * @task_movememory
+ *	Check permission before moving memory owned by process @p.
+ *	@p contains the task_struct for process.
+ *	Return 0 if permission is granted.
  * @task_kill:
  *	Check permission before sending signal @sig to @p.  @info can be NULL,
  *	the constant 1, or a pointer to a siginfo structure.  If @info is 1 or
@@ -1220,6 +1224,7 @@
 	int (*task_setscheduler) (struct task_struct * p, int policy,
 				  struct sched_param * lp);
 	int (*task_getscheduler) (struct task_struct * p);
+	int (*task_movememory) (struct task_struct * p);
 	int (*task_kill) (struct task_struct * p,
 			  struct siginfo * info, int sig);
 	int (*task_wait) (struct task_struct * p);
@@ -1865,6 +1870,11 @@
 	return security_ops->task_getscheduler (p);
 }
 
+static inline int security_task_movememory (struct task_struct *p)
+{
+	return security_ops->task_movememory (p);
+}
+
 static inline int security_task_kill (struct task_struct *p,
 				      struct siginfo *info, int sig)
 {
@@ -2512,6 +2522,11 @@
 	return 0;
 }
 
+static inline int security_task_movememory (struct task_struct *p)
+{
+	return 0;
+}
+
 static inline int security_task_kill (struct task_struct *p,
 				      struct siginfo *info, int sig)
 {