5 files changed, 13 insertions, 15 deletions
diff --git a/arch/um/kernel/tt/include/mode_kern-tt.h b/arch/um/kernel/tt/include/mode_kern-tt.h
index e0ca0e0b251..2a35b15c5fe 100644
--- a/arch/um/kernel/tt/include/mode_kern-tt.h
+++ b/arch/um/kernel/tt/include/mode_kern-tt.h
@@ -11,7 +11,7 @@
 #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);
diff --git a/arch/um/kernel/tt/include/uaccess-tt.h b/arch/um/kernel/tt/include/uaccess-tt.h
index aa6db384af8..dc2ebfa8c54 100644
--- a/arch/um/kernel/tt/include/uaccess-tt.h
+++ b/arch/um/kernel/tt/include/uaccess-tt.h
@@ -33,12 +33,6 @@ extern unsigned long uml_physmem;
          (((unsigned long) (addr) <= ((unsigned long) (addr) + (size))) && \
           (under_task_size(addr, size) || is_stack(addr, size))))
 
-static inline int verify_area_tt(int type, const void __user * addr,
-                                 unsigned long size)
-{
-	return(access_ok_tt(type, addr, size) ? 0 : -EFAULT);
-}
-
 extern unsigned long get_fault_addr(void);
 
 extern int __do_copy_from_user(void *to, const void *from, int n,
diff --git a/arch/um/kernel/tt/mem_user.c b/arch/um/kernel/tt/mem_user.c
index 3085267459b..03e58989538 100644
--- a/arch/um/kernel/tt/mem_user.c
+++ b/arch/um/kernel/tt/mem_user.c
@@ -12,6 +12,7 @@
 #include "tt.h"
 #include "mem_user.h"
 #include "user_util.h"
+#include "os.h"
 
 void remap_data(void *segment_start, void *segment_end, int w)
 {
diff --git a/arch/um/kernel/tt/process_kern.c b/arch/um/kernel/tt/process_kern.c
index a189a2b9293..cfaa373a6e7 100644
--- a/arch/um/kernel/tt/process_kern.c
+++ b/arch/um/kernel/tt/process_kern.c
@@ -23,10 +23,11 @@
 #include "mem_user.h"
 #include "tlb.h"
 #include "mode.h"
+#include "mode_kern.h"
 #include "init.h"
 #include "tt.h"
 
-void *switch_to_tt(void *prev, void *next, void *last)
+void switch_to_tt(void *prev, void *next)
 {
 	struct task_struct *from, *to, *prev_sched;
 	unsigned long flags;
@@ -36,8 +37,6 @@ void *switch_to_tt(void *prev, void *next, void *last)
 	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);
@@ -53,7 +52,6 @@ void *switch_to_tt(void *prev, void *next, void *last)
 	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))
@@ -85,8 +83,6 @@ void *switch_to_tt(void *prev, void *next, void *last)
 
 	flush_tlb_all();
 	local_irq_restore(flags);
-
-	return(current->thread.prev_sched);
 }
 
 void release_thread_tt(struct task_struct *task)
diff --git a/arch/um/kernel/tt/uaccess_user.c b/arch/um/kernel/tt/uaccess_user.c
index f01475512ec..8c220f054b6 100644
--- a/arch/um/kernel/tt/uaccess_user.c
+++ b/arch/um/kernel/tt/uaccess_user.c
@@ -22,8 +22,15 @@ int __do_copy_from_user(void *to, const void *from, int n,
 			       __do_copy, &faulted);
 	TASK_REGS(get_current())->tt = save;
 
-	if(!faulted) return(0);
-	else return(n - (fault - (unsigned long) from));
+	if(!faulted)
+		return 0;
+	else if (fault)
+		return n - (fault - (unsigned long) from);
+	else
+		/* In case of a general protection fault, we don't have the
+		 * fault address, so NULL is used instead. Pretend we didn't
+		 * copy anything. */
+		return n;
 }
 
 static void __do_strncpy(void *dst, const void *src, int count)