diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 2a8ccb9238b4719036aef70780b282e60f58acdd..b6b508ea71106f414deed5d11a9f43bbc8f6eb02 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -754,12 +754,12 @@ unsigned long get_wchan(struct task_struct *p)
 	if (!p || p == current || p->state == TASK_RUNNING)
 		return 0;
 	stack = (unsigned long)task_stack_page(p);
-	if (p->thread.sp < stack || p->thread.sp > stack+THREAD_SIZE)
+	if (p->thread.sp < stack || p->thread.sp >= stack+THREAD_SIZE)
 		return 0;
 	fp = *(u64 *)(p->thread.sp);
 	do {
 		if (fp < (unsigned long)stack ||
-		    fp > (unsigned long)stack+THREAD_SIZE)
+		    fp >= (unsigned long)stack+THREAD_SIZE)
 			return 0;
 		ip = *(u64 *)(fp+8);
 		if (!in_sched_functions(ip))