显示程序原始机器码

#include <stdio.h>

int main(void)
{
        printf("Hello, world\n");
        return 0;
}

技巧

使用“disassemble /r”命令可以用16进制形式显示程序的原始机器码。以上面程序为例：

(gdb) disassemble /r main
Dump of assembler code for function main:
   0x0000000000400530 <+0>:     55      push   %rbp
   0x0000000000400531 <+1>:     48 89 e5        mov    %rsp,%rbp
   0x0000000000400534 <+4>:     bf e0 05 40 00  mov    $0x4005e0,%edi
   0x0000000000400539 <+9>:     e8 d2 fe ff ff  callq  0x400410 <puts@plt>
   0x000000000040053e <+14>:    b8 00 00 00 00  mov    $0x0,%eax
   0x0000000000400543 <+19>:    5d      pop    %rbp
   0x0000000000400544 <+20>:    c3      retq
End of assembler dump.
(gdb) disassemble /r 0x0000000000400534,+4
Dump of assembler code from 0x400534 to 0x400538:
   0x0000000000400534 <main+4>: bf e0 05 40 00  mov    $0x4005e0,%edi
End of assembler dump.

详情参见 gdb手册