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 = prev;
+        struct task_struct *to= next;
+
+        to->thread.prev_sched = from;
+        set_current(to);
+
+       CHOOSE_MODE_PROC(switch_to_tt, switch_to_skas, prev, next);
+
+        return(current->thread.prev_sched);
+
 }
 
 void interrupt_end(void)
 
 #include "asm/ptrace.h"
 
 extern void flush_thread_skas(void);
-extern void *switch_to_skas(void *prev, void *next);
+extern void 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,
 
 #include "proc_mm.h"
 #include "registers.h"
 
-void *switch_to_skas(void *prev, void *next)
+void switch_to_skas(void *prev, void *next)
 {
        struct task_struct *from, *to;
 
        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);
 
        if(current->pid == 0)
                switch_timers(1);
-
-       return(current->thread.prev_sched);
 }
 
 extern void schedule_tail(struct task_struct *prev);
 
 #include "asm/ptrace.h"
 #include "asm/uaccess.h"
 
-extern void *switch_to_tt(void *prev, void *next);
+extern void 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);
 
 #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;
        from = prev;
        to = next;
 
-       to->thread.prev_sched = from;
-
        cpu = from->thread_info->cpu;
        if(cpu == 0)
                forward_interrupts(to->thread.mode.tt.extern_pid);
        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))
 
        flush_tlb_all();
        local_irq_restore(flags);
-
-       return(current->thread.prev_sched);
 }
 
 void release_thread_tt(struct task_struct *task)