diff --git a/Dockerfile b/Dockerfile
index c87af49..74dc331 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -2,6 +2,10 @@
 # FROM debian
 FROM rockylinux:8.8.20230518
 
+# copy 并安装 /root/diagnose-tools/rpmbuild/RPMS/x86_64/diagnose-tools-2.1-release.el8.x86_64.rpm
+# 拷贝 RPM 文件到 Docker 镜像中
+# COPY /diagnose-tools-2.1-release.el8.x86_64.rpm 
+
 # 安装 RPM 文件
 # RUN dnf install -y /diagnose-tools-2.1-release.el8.x86_64.rpm && \
 #     rm -f /diagnose-tools-2.1-release.el8.x86_64.rpm
@@ -11,10 +15,5 @@ COPY build/userstack /userstack
 # 使拷贝进去的 userstack 文件可执行
 RUN ls /
 RUN chmod +x /userstack
-
-# copy 并安装 /root/diagnose-tools/rpmbuild/RPMS/x86_64/diagnose-tools-2.1-release.el8.x86_64.rpm
-# 拷贝 RPM 文件到 Docker 镜像中
-COPY /diagnose-tools-2.1-release.el8.x86_64.rpm /
-
 # 设置容器启动时运行的命令
 ENTRYPOINT ["/userstack"]
\ No newline at end of file
diff --git a/Makefile b/Makefile
index 7f64ff1..8640e68 100644
--- a/Makefile
+++ b/Makefile
@@ -23,7 +23,7 @@ $(OUTPUT_DIR)/%: $(TDIR)/%.c
 $(OUTPUT_DIR)/$(USTACK): $(TDIR)/$(USTACK).c
 	mkdir -p $(@D)
 	# $(CC) -g $(CFLAGS) -o $@ $< -lunwind -lunwind-x86_64
-	$(CC) -g -O2 $(CFLAGS) -o $@ $<
+	$(CC) -g -O2 $(CFLAGS) -o $@ $< -lpthread
 
 # $(SPID): $(TDIR)/stack-pid.c
 # 	mkdir -p $(OUTPUT_DIR)
diff --git a/testcase/userstack.c b/testcase/userstack.c
index 34b74d5..003f19e 100644
--- a/testcase/userstack.c
+++ b/testcase/userstack.c
@@ -1,8 +1,10 @@
 #include <stdio.h>
 // #include <libunwind.h>
 #include <unistd.h>
+#include <pthread.h>
 
-void customFunction1(int n);
+// void customFunction1(int n);
+void *customFunction1(void *n);
 void customFunction2(int n);
 void customFunction3(int n);
 
@@ -33,34 +35,61 @@ void customFunction3(int n);
 //   }
 // }
 
-void customFunction1(int n) {
-    if(n <= 0) {
+void *customFunction1(void *n) {
+    int num = *((int *)n);
+    if(num <= 0) {
         printf("End of recursion\n");
-        // output backtrace
         printf("pid: %d\n", getpid());
-        // backtrace();
         while (1) {
             sleep(1);
         } // never return, keep stack
-        return;
+        return NULL;
     } else {
         printf("Calling customFunction2\n");
-        customFunction2(n-1);
+        customFunction2(num-1);
     }
+    return NULL;
 }
 
 void customFunction2(int n) {
-    printf("Calling customFunction3\n");
-    customFunction3(n);
+    printf("Calling customFunction2\n");
+    if(n <= 0) {
+        printf("End of recursion\n");
+        printf("pid: %d\n", getpid());
+        while (1) {
+            sleep(1);
+        } // never return, keep stack
+        return NULL;
+    }
+    customFunction3(n-1);
 }
 
 void customFunction3(int n) {
-    printf("Calling customFunction1\n");
-    customFunction1(n);
+    printf("Calling customFunction3\n");
+    if(n <= 0) {
+        printf("End of recursion\n");
+        printf("pid: %d\n", getpid());
+        while (1) {
+            sleep(1);
+        } // never return, keep stack
+        return NULL;
+    }
+    customFunction2(n-1);
 }
 
 int main() {
-    customFunction1(10);
+    int num1 = 4;
+    int num2 = 5;
+    int num3 = 6;
 
+    pthread_t thread_id1, thread_id2, thread_id3;
+
+    pthread_create(&thread_id1, NULL, customFunction1, &num1);
+    pthread_create(&thread_id2, NULL, customFunction1, &num2);
+    pthread_create(&thread_id3, NULL, customFunction1, &num3);
+
+    pthread_join(thread_id1, NULL);
+    pthread_join(thread_id2, NULL);
+    pthread_join(thread_id3, NULL);
     return 0;
 }
\ No newline at end of file