diff --git a/b/2/clone.c b/b/2/clone.c
new file mode 100644
index 0000000..2208dc0
--- /dev/null
+++ b/b/2/clone.c
@@ -0,0 +1,66 @@
+/*
+ * 测试成功时输出：
+ *   "clone success."
+ * 测试失败时输出：
+ *   "clone error."
+ */
+#define __LIBRARY__
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <assert.h>
+#include <signal.h>
+#include "new.h"
+
+int clone(int (*fn)(void *), void *child_stack, ...)
+{
+	register int res;
+	va_list arg;
+
+	va_start(arg,child_stack);
+	__asm__("int $0x80"
+		:"=a" (res)
+		:"0" (__NR_clone),"b" (fn),"c" (child_stack),
+		"d" (va_arg(arg,int)));
+	if (res>=0)
+		return res;
+	errno = -res;
+	return -1;
+}
+
+int g_shared = 0;
+size_t stack[1024] = {0};
+int child_pid;
+
+static int child_func(void * arg){
+    g_shared = 1;
+    printf("  Child says hello.\n");
+    exit(0);
+}
+
+void test_clone(void){
+    int wstatus, ret;
+    child_pid = clone(child_func, stack+1024, SIGCHLD|CLONE_VM);
+    assert(child_pid != -1);
+
+    if (child_pid == 0){
+        exit(0);
+    }
+    printf("child pid: %d\n", child_pid);
+
+	ret = wait(&wstatus);
+	if(ret == child_pid) {
+        if (g_shared == 1) {
+            printf("clone success.\n");                
+        }
+    }
+	else {
+        printf("clone error.\n");    
+    }
+}
+
+int main(void){
+    test_clone();
+    return 0;
+}