diff -uNr -x '.dep*' -x '.hdep*' -x '*.[oas]' -x '*~' -x '#*' -x '*CVS*' -x '*.orig' -x '*.rej' -x '*.old' -x '.menu*' -x asm -x local.h -x System.map -x autoconf.h -x compile.h -x version.h -x .version -x defkaymap.c -x uni_hash.tbl linux-2.6.13/arch/um/kernel/process_kern.c linux-2.6.13-stack/arch/um/kernel/process_kern.c
--- linux-2.6.13/arch/um/kernel/process_kern.c	2005-08-28 19:41:01.000000000 -0400
+++ linux-2.6.13-stack/arch/um/kernel/process_kern.c	2005-08-31 17:50:17.000000000 -0400
@@ -113,8 +113,17 @@
 
 void *_switch_to(void *prev, void *next, void *last)
 {
-	return(CHOOSE_MODE(switch_to_tt(prev, next), 
-			   switch_to_skas(prev, next)));
+        struct task_struct *from=(struct task_struct*)prev;
+        struct task_struct *to=(struct task_struct*)next;
+
+        to->thread.prev_sched = from;
+        set_current(to);
+
+          CHOOSE_MODE(switch_to_tt(prev, next),
+             switch_to_skas(prev, next));
+
+        return(current->thread.prev_sched); 
+
 }
 
 void interrupt_end(void)
diff -uNr -x '.dep*' -x '.hdep*' -x '*.[oas]' -x '*~' -x '#*' -x '*CVS*' -x '*.orig' -x '*.rej' -x '*.old' -x '.menu*' -x asm -x local.h -x System.map -x autoconf.h -x compile.h -x version.h -x .version -x defkaymap.c -x uni_hash.tbl linux-2.6.13/arch/um/kernel/skas/include/mode_kern-skas.h linux-2.6.13-stack/arch/um/kernel/skas/include/mode_kern-skas.h
--- linux-2.6.13/arch/um/kernel/skas/include/mode_kern-skas.h	2005-08-28 19:41:01.000000000 -0400
+++ linux-2.6.13-stack/arch/um/kernel/skas/include/mode_kern-skas.h	2005-08-30 16:46:17.000000000 -0400
@@ -11,7 +11,7 @@
 #include "asm/ptrace.h"
 
 extern void flush_thread_skas(void);
-extern void *switch_to_skas(void *prev, void *next);
+extern int switch_to_skas(void *prev, void *next);
 extern void start_thread_skas(struct pt_regs *regs, unsigned long eip,
 			      unsigned long esp);
 extern int copy_thread_skas(int nr, unsigned long clone_flags,
diff -uNr -x '.dep*' -x '.hdep*' -x '*.[oas]' -x '*~' -x '#*' -x '*CVS*' -x '*.orig' -x '*.rej' -x '*.old' -x '.menu*' -x asm -x local.h -x System.map -x autoconf.h -x compile.h -x version.h -x .version -x defkaymap.c -x uni_hash.tbl linux-2.6.13/arch/um/kernel/skas/process_kern.c linux-2.6.13-stack/arch/um/kernel/skas/process_kern.c
--- linux-2.6.13/arch/um/kernel/skas/process_kern.c	2005-08-28 19:41:01.000000000 -0400
+++ linux-2.6.13-stack/arch/um/kernel/skas/process_kern.c	2005-08-31 15:48:35.000000000 -0400
@@ -24,7 +24,7 @@
 #include "proc_mm.h"
 #include "registers.h"
 
-void *switch_to_skas(void *prev, void *next)
+int switch_to_skas(void *prev, void *next)
 {
 	struct task_struct *from, *to;
 
@@ -35,8 +35,6 @@
 	if(current->pid == 0)
 		switch_timers(0);
 
-	to->thread.prev_sched = from;
-	set_current(to);
 
 	switch_threads(&from->thread.mode.skas.switch_buf, 
 		       to->thread.mode.skas.switch_buf);
@@ -44,7 +42,7 @@
 	if(current->pid == 0)
 		switch_timers(1);
 
-	return(current->thread.prev_sched);
+	return(0);
 }
 
 extern void schedule_tail(struct task_struct *prev);
diff -uNr -x '.dep*' -x '.hdep*' -x '*.[oas]' -x '*~' -x '#*' -x '*CVS*' -x '*.orig' -x '*.rej' -x '*.old' -x '.menu*' -x asm -x local.h -x System.map -x autoconf.h -x compile.h -x version.h -x .version -x defkaymap.c -x uni_hash.tbl linux-2.6.13/arch/um/kernel/tt/include/mode_kern-tt.h linux-2.6.13-stack/arch/um/kernel/tt/include/mode_kern-tt.h
--- linux-2.6.13/arch/um/kernel/tt/include/mode_kern-tt.h	2005-08-28 19:41:01.000000000 -0400
+++ linux-2.6.13-stack/arch/um/kernel/tt/include/mode_kern-tt.h	2005-08-31 11:15:55.000000000 -0400
@@ -11,7 +11,7 @@
 #include "asm/ptrace.h"
 #include "asm/uaccess.h"
 
-extern void *switch_to_tt(void *prev, void *next);
+extern int switch_to_tt(void *prev, void *next);
 extern void flush_thread_tt(void);
 extern void start_thread_tt(struct pt_regs *regs, unsigned long eip,
 			   unsigned long esp);
diff -uNr -x '.dep*' -x '.hdep*' -x '*.[oas]' -x '*~' -x '#*' -x '*CVS*' -x '*.orig' -x '*.rej' -x '*.old' -x '.menu*' -x asm -x local.h -x System.map -x autoconf.h -x compile.h -x version.h -x .version -x defkaymap.c -x uni_hash.tbl linux-2.6.13/arch/um/kernel/tt/process_kern.c linux-2.6.13-stack/arch/um/kernel/tt/process_kern.c
--- linux-2.6.13/arch/um/kernel/tt/process_kern.c	2005-08-28 19:41:01.000000000 -0400
+++ linux-2.6.13-stack/arch/um/kernel/tt/process_kern.c	2005-08-31 15:48:31.000000000 -0400
@@ -26,7 +26,7 @@
 #include "init.h"
 #include "tt.h"
 
-void *switch_to_tt(void *prev, void *next, void *last)
+int switch_to_tt(void *prev, void *next, void *last)
 {
 	struct task_struct *from, *to, *prev_sched;
 	unsigned long flags;
@@ -36,7 +36,6 @@
 	from = prev;
 	to = next;
 
-	to->thread.prev_sched = from;
 
 	cpu = from->thread_info->cpu;
 	if(cpu == 0)
@@ -53,7 +52,6 @@
 	forward_pending_sigio(to->thread.mode.tt.extern_pid);
 
 	c = 0;
-	set_current(to);
 
 	err = os_write_file(to->thread.mode.tt.switch_pipe[1], &c, sizeof(c));
 	if(err != sizeof(c))
@@ -86,7 +84,7 @@
 	flush_tlb_all();
 	local_irq_restore(flags);
 
-	return(current->thread.prev_sched);
+        return(0);
 }
 
 void release_thread_tt(struct task_struct *task)