在 《Linux C一站式编程》中有这样一个问题：

.section .data

 .section .text
 .globl _start
_start:
 movl $1, %eax  # this is the linux kernel command
        # number (system call) for exiting
        # a program

 movl $4, %ebx  # this is the status number we will
        # return to the operating system.
        # Change this around and it will
        # return different things to
        # echo $?

 int $0x80  # this wakes up the kernel to run
        # the exit command

在上面的汇编代码中，如果将 int $0x80 这一句去掉，也能够编译链接成功，但是却会导致一个段错误，请问这是为什么？

谢谢大家了～