远端gdbserver已经起来，本地使用gdb已经连接上gdbserver，但是本地提示找不到符号文件：

warning: Could not load vsyscall page because no executable was specified

try using the "file" command first.

那么使用file命令，指定被调试的可执行文件即可：

file /opt/linuxshare/helloworld/main


这里要注意一下，file指定的main已经是一个ELF可执行文件，也就是正在被调试的程序，另外，这个文件其实是存在于远端磁盘上，但是已经被mount到了本地机器上。


file成功后即可看到源码：

(gdb) file /opt/linuxshare/helloworld/main

A program is being debugged already.

Are you sure you want to change the file? (y or n) y

Reading symbols from /opt/linuxshare/helloworld/main...done.

(gdb) b main

Breakpoint 1 at 0x40055c: file main.c, line 3.

(gdb) info b

Num Type Disp Enb Address What

1 breakpoint keep y 0x000000000040055c in main at main.c:3

(gdb) l

1#include <stdio.h>

2int main() {

3 printf("Hello World\n");

4

5 int i = 0;

6 while(1)

7 {

8sleep(3);

9printf("time: %d\n", ++i);

10 }