diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
old mode 100644
new mode 100755
index 65562d0b14a65fc0b5d14909c1bf9c4fa8eec8aa..7e41ac5033adc4ecbaf7dd3aba22e53e93d0275f
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -43,6 +43,7 @@
 #include <asm/io_bitmap.h>
 #include <asm/proto.h>
 #include <asm/frame.h>
+#include <asm/unwind.h>
 
 #include "process.h"
 
@@ -918,13 +919,23 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
  */
 unsigned long get_wchan(struct task_struct *p)
 {
-	unsigned long entry = 0;
+	struct unwind_state state;
+	unsigned long addr = 0;
 
 	if (p == current || p->state == TASK_RUNNING)
 		return 0;
 
-	stack_trace_save_tsk(p, &entry, 1, 0);
-	return entry;
+	for (unwind_start(&state, p, NULL, NULL); !unwind_done(&state);
+	     unwind_next_frame(&state)) {
+	        addr = unwind_get_return_address(&state);
+	        if (!addr)
+	                break;
+	        if (in_sched_functions(addr))
+	                continue;
+	        break;
+	}
+
+	return addr;
 }
 
 long do_arch_prctl_common(struct task_struct *task, int option,