--- olpc-2.6-master.00/kernel/sys.c	2007-02-28 20:05:29.000000000 -0500
+++ olpc-2.6-master-vs22x.02/kernel/sys.c	2007-03-01 11:52:20.000000000 -0500
@@ -632,7 +637,8 @@ asmlinkage long sys_setpriority(int whic
 			if (!who)
 				who = current->uid;
 			else
-				if ((who != current->uid) && !(user = find_user(who)))
+				if ((who != current->uid) &&
+					!(user = find_user(vx_current_xid(), who)))
 					goto out_unlock;	/* No processes for this user */
 
 			do_each_thread(g, p)
--- olpc-2.6-master.00/kernel/sys.c	2007-02-28 20:05:29.000000000 -0500
+++ olpc-2.6-master-vs22x.02/kernel/sys.c	2007-03-01 11:52:20.000000000 -0500
@@ -694,7 +700,8 @@ asmlinkage long sys_getpriority(int whic
 			if (!who)
 				who = current->uid;
 			else
-				if ((who != current->uid) && !(user = find_user(who)))
+				if ((who != current->uid) &&
+					!(user = find_user(vx_current_xid(), who)))
 					goto out_unlock;	/* No processes for this user */
 
 			do_each_thread(g, p)
--- olpc-2.6-master.00/kernel/sys.c	2007-02-28 20:05:29.000000000 -0500
+++ olpc-2.6-master-vs22x.02/kernel/sys.c	2007-03-01 11:52:20.000000000 -0500
@@ -1016,7 +1029,7 @@ static int set_user(uid_t new_ruid, int 
 {
 	struct user_struct *new_user;
 
-	new_user = alloc_uid(new_ruid);
+	new_user = alloc_uid(vx_current_xid(), new_ruid);
 	if (!new_user)
 		return -EAGAIN;
 
--- olpc-2.6-master.00/kernel/user.c	2007-02-28 20:05:29.000000000 -0500
+++ olpc-2.6-master-vs22x.02/kernel/user.c	2007-03-01 11:52:20.000000000 -0500
@@ -23,8 +23,8 @@
 #define UIDHASH_BITS (CONFIG_BASE_SMALL ? 3 : 8)
 #define UIDHASH_SZ		(1 << UIDHASH_BITS)
 #define UIDHASH_MASK		(UIDHASH_SZ - 1)
-#define __uidhashfn(uid)	(((uid >> UIDHASH_BITS) + uid) & UIDHASH_MASK)
-#define uidhashentry(uid)	(uidhash_table + __uidhashfn((uid)))
+#define __uidhashfn(xid,uid)	((((uid) >> UIDHASH_BITS) + ((uid)^(xid))) & UIDHASH_MASK)
+#define uidhashentry(xid,uid)	(uidhash_table + __uidhashfn((xid),(uid)))
 
 static struct kmem_cache *uid_cachep;
 static struct list_head uidhash_table[UIDHASH_SZ];
--- olpc-2.6-master.00/kernel/user.c	2007-02-28 20:05:29.000000000 -0500
+++ olpc-2.6-master-vs22x.02/kernel/user.c	2007-03-01 11:52:20.000000000 -0500
@@ -66,7 +66,7 @@ static inline void uid_hash_remove(struc
 	list_del(&up->uidhash_list);
 }
 
-static inline struct user_struct *uid_hash_find(uid_t uid, struct list_head *hashent)
+static inline struct user_struct *uid_hash_find(xid_t xid, uid_t uid, struct list_head *hashent)
 {
 	struct list_head *up;
 
--- olpc-2.6-master.00/kernel/user.c	2007-02-28 20:05:29.000000000 -0500
+++ olpc-2.6-master-vs22x.02/kernel/user.c	2007-03-01 11:52:20.000000000 -0500
@@ -75,7 +75,7 @@ static inline struct user_struct *uid_ha
 
 		user = list_entry(up, struct user_struct, uidhash_list);
 
-		if(user->uid == uid) {
+		if(user->uid == uid && user->xid == xid) {
 			atomic_inc(&user->__count);
 			return user;
 		}
--- olpc-2.6-master.00/kernel/user.c	2007-02-28 20:05:29.000000000 -0500
+++ olpc-2.6-master-vs22x.02/kernel/user.c	2007-03-01 11:52:20.000000000 -0500
@@ -90,7 +90,7 @@ static inline struct user_struct *uid_ha
  *
  * If the user_struct could not be found, return NULL.
  */
-struct user_struct *find_user(uid_t uid)
+struct user_struct *find_user(xid_t xid, uid_t uid)
 {
 	struct user_struct *ret;
 	unsigned long flags;
--- olpc-2.6-master.00/kernel/user.c	2007-02-28 20:05:29.000000000 -0500
+++ olpc-2.6-master-vs22x.02/kernel/user.c	2007-03-01 11:52:20.000000000 -0500
@@ -96,7 +96,7 @@ *****
 	unsigned long flags;
 
 	spin_lock_irqsave(&uidhash_lock, flags);
-	ret = uid_hash_find(uid, uidhashentry(uid));
+	ret = uid_hash_find(xid, uid, uidhashentry(xid, uid));
 	spin_unlock_irqrestore(&uidhash_lock, flags);
 	return ret;
 }
--- olpc-2.6-master.00/kernel/user.c	2007-02-28 20:05:29.000000000 -0500
+++ olpc-2.6-master-vs22x.02/kernel/user.c	2007-03-01 11:52:20.000000000 -0500
@@ -120,9 +120,9 @@ void free_uid(struct user_struct *up)
 	}
 }
 
-struct user_struct * alloc_uid(uid_t uid)
+struct user_struct * alloc_uid(xid_t xid, uid_t uid)
 {
-	struct list_head *hashent = uidhashentry(uid);
+	struct list_head *hashent = uidhashentry(xid, uid);
 	struct user_struct *up;
 
 	spin_lock_irq(&uidhash_lock);
--- olpc-2.6-master.00/kernel/user.c	2007-02-28 20:05:29.000000000 -0500
+++ olpc-2.6-master-vs22x.02/kernel/user.c	2007-03-01 11:52:20.000000000 -0500
@@ -126,7 +126,7 @@ *****
 	struct user_struct *up;
 
 	spin_lock_irq(&uidhash_lock);
-	up = uid_hash_find(uid, hashent);
+	up = uid_hash_find(xid, uid, hashent);
 	spin_unlock_irq(&uidhash_lock);
 
 	if (!up) {
--- olpc-2.6-master.00/kernel/user.c	2007-02-28 20:05:29.000000000 -0500
+++ olpc-2.6-master-vs22x.02/kernel/user.c	2007-03-01 11:52:20.000000000 -0500
@@ -136,6 +136,7 @@ struct user_struct * alloc_uid(uid_t uid
 		if (!new)
 			return NULL;
 		new->uid = uid;
+		new->xid = xid;
 		atomic_set(&new->__count, 1);
 		atomic_set(&new->processes, 0);
 		atomic_set(&new->files, 0);
--- olpc-2.6-master.00/kernel/user.c	2007-02-28 20:05:29.000000000 -0500
+++ olpc-2.6-master-vs22x.02/kernel/user.c	2007-03-01 11:52:20.000000000 -0500
@@ -158,7 +159,7 @@ struct user_struct * alloc_uid(uid_t uid
 		 * on adding the same user already..
 		 */
 		spin_lock_irq(&uidhash_lock);
-		up = uid_hash_find(uid, hashent);
+		up = uid_hash_find(xid, uid, hashent);
 		if (up) {
 			key_put(new->uid_keyring);
 			key_put(new->session_keyring);
--- olpc-2.6-master.00/kernel/user.c	2007-02-28 20:05:29.000000000 -0500
+++ olpc-2.6-master-vs22x.02/kernel/user.c	2007-03-01 11:52:20.000000000 -0500
@@ -215,7 +216,7 @@ static int __init uid_cache_init(void)
 
 	/* Insert the root user immediately (init already runs as root) */
 	spin_lock_irq(&uidhash_lock);
-	uid_hash_insert(&root_user, uidhashentry(0));
+	uid_hash_insert(&root_user, uidhashentry(0,0));
 	spin_unlock_irq(&uidhash_lock);
 
 	return 0;
--- olpc-2.6-master.00/include/linux/sched.h	2007-02-28 20:05:29.000000000 -0500
+++ olpc-2.6-master-vs22x.02/include/linux/sched.h	2007-03-01 11:52:20.000000000 -0500
@@ -555,9 +562,10 @@ struct user_struct {
 	/* Hash table maintenance information */
 	struct list_head uidhash_list;
 	uid_t uid;
+	xid_t xid;
 };
 
-extern struct user_struct *find_user(uid_t);
+extern struct user_struct *find_user(xid_t, uid_t);
 
 extern struct user_struct root_user;
 #define INIT_USER (&root_user)
--- olpc-2.6-master.00/include/linux/sched.h	2007-02-28 20:05:29.000000000 -0500
+++ olpc-2.6-master-vs22x.02/include/linux/sched.h	2007-03-01 11:52:20.000000000 -0500
@@ -1270,7 +1290,7 @@ *****
 extern void __set_special_pids(pid_t session, pid_t pgrp);
 
 /* per-UID process charging. */
-extern struct user_struct * alloc_uid(uid_t);
+extern struct user_struct * alloc_uid(xid_t, uid_t);
 static inline struct user_struct *get_uid(struct user_struct *u)
 {
 	atomic_inc(&u->__count);
--- olpc-2.6-master.00/fs/ioprio.c	2007-02-28 20:05:28.000000000 -0500
+++ olpc-2.6-master-vs22x.02/fs/ioprio.c	2007-03-01 11:52:20.000000000 -0500
@@ -112,7 +113,7 @@ asmlinkage long sys_ioprio_set(int which
 			if (!who)
 				user = current->user;
 			else
-				user = find_user(who);
+				user = find_user(vx_current_xid(), who);
 
 			if (!user)
 				break;
--- olpc-2.6-master.00/fs/ioprio.c	2007-02-28 20:05:28.000000000 -0500
+++ olpc-2.6-master-vs22x.02/fs/ioprio.c	2007-03-01 11:52:20.000000000 -0500
@@ -203,7 +204,7 @@ asmlinkage long sys_ioprio_get(int which
 			if (!who)
 				user = current->user;
 			else
-				user = find_user(who);
+				user = find_user(vx_current_xid(), who);
 
 			if (!user)
 				break;