C源代码反汇编（Centos7）-蒲公英云

gcc

执行指令 gcc -v，如果发现找不到gcc 指令，则执行yum install gcc 进行安装.

objdump

执行指令 whereis objdump。就会看见objdump的路径，是Linux默认的指令。

C源代码文件（文件内容如下）

#include <stdio.h>
static int add(int a, int b)
{
    return a + b;
}
int main(int argc, const char *argv[])
{
    int a = 1;
    int b = 1;
    int c;
    c = add(a, b);
    printf(" %d + %d = %d\n", a, b, c);
    return c;
}

编译C源代码和生产反汇编文件

编译：gcc -o gcc_objdump objdump.c

反汇编：objdump -l -x -d gcc_objdump > objdump.dmp
在这里插入图片描述

分析

执行gcc_objdump文件，会得到 1 + 1 = 2；执行指令是 ./gcc_objdump
gcc_objdump是一个可执行的elf文件。ELF文件由4部分组成，分别是ELF头（ELF header）、程序头表（Program header table）、节（Section）和节头表（Section header table）。实际上，一个文件中不一定包含全部内容，而且他们的位置也未必如同所示这样安排，只有ELF头的位置是固定的，其余各部分的位置、大小等信息由ELF头中的各项值来决定。
objdump.dmp文件可以由vim工具打开，也可以使用EditPlus打开。

objdump.dmp内容如下

gcc_objdump:     file format elf64-x86-64
gcc_objdump
architecture: i386:x86-64, flags 0x00000112:
EXEC_P, HAS_SYMS, D_PAGED
start address 0x0000000000400430
Program Header:
    PHDR off    0x0000000000000040 vaddr 0x0000000000400040 paddr 0x0000000000400040 align 2**3
         filesz 0x00000000000001f8 memsz 0x00000000000001f8 flags r-x
  INTERP off    0x0000000000000238 vaddr 0x0000000000400238 paddr 0x0000000000400238 align 2**0
         filesz 0x000000000000001c memsz 0x000000000000001c flags r--
    LOAD off    0x0000000000000000 vaddr 0x0000000000400000 paddr 0x0000000000400000 align 2**21
         filesz 0x0000000000000774 memsz 0x0000000000000774 flags r-x
    LOAD off    0x0000000000000e10 vaddr 0x0000000000600e10 paddr 0x0000000000600e10 align 2**21
         filesz 0x000000000000021c memsz 0x0000000000000220 flags rw-
 DYNAMIC off    0x0000000000000e28 vaddr 0x0000000000600e28 paddr 0x0000000000600e28 align 2**3
         filesz 0x00000000000001d0 memsz 0x00000000000001d0 flags rw-
    NOTE off    0x0000000000000254 vaddr 0x0000000000400254 paddr 0x0000000000400254 align 2**2
         filesz 0x0000000000000044 memsz 0x0000000000000044 flags r--
EH_FRAME off    0x0000000000000620 vaddr 0x0000000000400620 paddr 0x0000000000400620 align 2**2
         filesz 0x000000000000003c memsz 0x000000000000003c flags r--
   STACK off    0x0000000000000000 vaddr 0x0000000000000000 paddr 0x0000000000000000 align 2**4
         filesz 0x0000000000000000 memsz 0x0000000000000000 flags rw-
   RELRO off    0x0000000000000e10 vaddr 0x0000000000600e10 paddr 0x0000000000600e10 align 2**0
         filesz 0x00000000000001f0 memsz 0x00000000000001f0 flags r--
Dynamic Section:
  NEEDED               libc.so.6
  INIT                 0x00000000004003c8
  FINI                 0x00000000004005f4
  INIT_ARRAY           0x0000000000600e10
  INIT_ARRAYSZ         0x0000000000000008
  FINI_ARRAY           0x0000000000600e18
  FINI_ARRAYSZ         0x0000000000000008
  GNU_HASH             0x0000000000400298
  STRTAB               0x0000000000400318
  SYMTAB               0x00000000004002b8
  STRSZ                0x000000000000003f
  SYMENT               0x0000000000000018
  DEBUG                0x0000000000000000
  PLTGOT               0x0000000000601000
  PLTRELSZ             0x0000000000000030
  PLTREL               0x0000000000000007
  JMPREL               0x0000000000400398
  RELA                 0x0000000000400380
  RELASZ               0x0000000000000018
  RELAENT              0x0000000000000018
  VERNEED              0x0000000000400360
  VERNEEDNUM           0x0000000000000001
  VERSYM               0x0000000000400358
Version References:
  required from libc.so.6:
    0x09691a75 0x00 02 GLIBC_2.2.5
Sections:
Idx Name          Size      VMA               LMA               File off  Algn
  0 .interp       0000001c  0000000000400238  0000000000400238  00000238  2**0
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  1 .note.ABI-tag 00000020  0000000000400254  0000000000400254  00000254  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  2 .note.gnu.build-id 00000024  0000000000400274  0000000000400274  00000274  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  3 .gnu.hash     0000001c  0000000000400298  0000000000400298  00000298  2**3
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  4 .dynsym       00000060  00000000004002b8  00000000004002b8  000002b8  2**3
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  5 .dynstr       0000003f  0000000000400318  0000000000400318  00000318  2**0
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  6 .gnu.version  00000008  0000000000400358  0000000000400358  00000358  2**1
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  7 .gnu.version_r 00000020  0000000000400360  0000000000400360  00000360  2**3
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  8 .rela.dyn     00000018  0000000000400380  0000000000400380  00000380  2**3
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  9 .rela.plt     00000030  0000000000400398  0000000000400398  00000398  2**3
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
 10 .init         0000001a  00000000004003c8  00000000004003c8  000003c8  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
 11 .plt          00000030  00000000004003f0  00000000004003f0  000003f0  2**4
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
 12 .plt.got      00000008  0000000000400420  0000000000400420  00000420  2**3
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
 13 .text         000001c2  0000000000400430  0000000000400430  00000430  2**4
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
 14 .fini         00000009  00000000004005f4  00000000004005f4  000005f4  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
 15 .rodata       0000001f  0000000000400600  0000000000400600  00000600  2**3
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
 16 .eh_frame_hdr 0000003c  0000000000400620  0000000000400620  00000620  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
 17 .eh_frame     00000114  0000000000400660  0000000000400660  00000660  2**3
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
 18 .init_array   00000008  0000000000600e10  0000000000600e10  00000e10  2**3
                  CONTENTS, ALLOC, LOAD, DATA
 19 .fini_array   00000008  0000000000600e18  0000000000600e18  00000e18  2**3
                  CONTENTS, ALLOC, LOAD, DATA
 20 .jcr          00000008  0000000000600e20  0000000000600e20  00000e20  2**3
                  CONTENTS, ALLOC, LOAD, DATA
 21 .dynamic      000001d0  0000000000600e28  0000000000600e28  00000e28  2**3
                  CONTENTS, ALLOC, LOAD, DATA
 22 .got          00000008  0000000000600ff8  0000000000600ff8  00000ff8  2**3
                  CONTENTS, ALLOC, LOAD, DATA
 23 .got.plt      00000028  0000000000601000  0000000000601000  00001000  2**3
                  CONTENTS, ALLOC, LOAD, DATA
 24 .data         00000004  0000000000601028  0000000000601028  00001028  2**0
                  CONTENTS, ALLOC, LOAD, DATA
 25 .bss          00000004  000000000060102c  000000000060102c  0000102c  2**0
                  ALLOC
 26 .comment      0000002d  0000000000000000  0000000000000000  0000102c  2**0
                  CONTENTS, READONLY
SYMBOL TABLE:
0000000000400238 l    d  .interp    0000000000000000              .interp
0000000000400254 l    d  .note.ABI-tag    0000000000000000              .note.ABI-tag
0000000000400274 l    d  .note.gnu.build-id    0000000000000000              .note.gnu.build-id
0000000000400298 l    d  .gnu.hash    0000000000000000              .gnu.hash
00000000004002b8 l    d  .dynsym    0000000000000000              .dynsym
0000000000400318 l    d  .dynstr    0000000000000000              .dynstr
0000000000400358 l    d  .gnu.version    0000000000000000              .gnu.version
0000000000400360 l    d  .gnu.version_r    0000000000000000              .gnu.version_r
0000000000400380 l    d  .rela.dyn    0000000000000000              .rela.dyn
0000000000400398 l    d  .rela.plt    0000000000000000              .rela.plt
00000000004003c8 l    d  .init    0000000000000000              .init
00000000004003f0 l    d  .plt    0000000000000000              .plt
0000000000400420 l    d  .plt.got    0000000000000000              .plt.got
0000000000400430 l    d  .text    0000000000000000              .text
00000000004005f4 l    d  .fini    0000000000000000              .fini
0000000000400600 l    d  .rodata    0000000000000000              .rodata
0000000000400620 l    d  .eh_frame_hdr    0000000000000000              .eh_frame_hdr
0000000000400660 l    d  .eh_frame    0000000000000000              .eh_frame
0000000000600e10 l    d  .init_array    0000000000000000              .init_array
0000000000600e18 l    d  .fini_array    0000000000000000              .fini_array
0000000000600e20 l    d  .jcr    0000000000000000              .jcr
0000000000600e28 l    d  .dynamic    0000000000000000              .dynamic
0000000000600ff8 l    d  .got    0000000000000000              .got
0000000000601000 l    d  .got.plt    0000000000000000              .got.plt
0000000000601028 l    d  .data    0000000000000000              .data
000000000060102c l    d  .bss    0000000000000000              .bss
0000000000000000 l    d  .comment    0000000000000000              .comment
0000000000000000 l    df *ABS*    0000000000000000              crtstuff.c
0000000000600e20 l     O .jcr    0000000000000000              __JCR_LIST__
0000000000400460 l     F .text    0000000000000000              deregister_tm_clones
0000000000400490 l     F .text    0000000000000000              register_tm_clones
00000000004004d0 l     F .text    0000000000000000              __do_global_dtors_aux
000000000060102c l     O .bss    0000000000000001              completed.6355
0000000000600e18 l     O .fini_array    0000000000000000              __do_global_dtors_aux_fini_array_entry
00000000004004f0 l     F .text    0000000000000000              frame_dummy
0000000000600e10 l     O .init_array    0000000000000000              __frame_dummy_init_array_entry
0000000000000000 l    df *ABS*    0000000000000000              objdump.c
000000000040051d l     F .text    0000000000000014              add_a_and_b
0000000000000000 l    df *ABS*    0000000000000000              crtstuff.c
0000000000400770 l     O .eh_frame    0000000000000000              __FRAME_END__
0000000000600e20 l     O .jcr    0000000000000000              __JCR_END__
0000000000000000 l    df *ABS*    0000000000000000              
0000000000600e18 l       .init_array    0000000000000000              __init_array_end
0000000000600e28 l     O .dynamic    0000000000000000              _DYNAMIC
0000000000600e10 l       .init_array    0000000000000000              __init_array_start
0000000000400620 l       .eh_frame_hdr    0000000000000000              __GNU_EH_FRAME_HDR
0000000000601000 l     O .got.plt    0000000000000000              _GLOBAL_OFFSET_TABLE_
00000000004005f0 g     F .text    0000000000000002              __libc_csu_fini
0000000000601028  w      .data    0000000000000000              data_start
000000000060102c g       .data    0000000000000000              _edata
00000000004005f4 g     F .fini    0000000000000000              _fini
0000000000000000       F *UND*    0000000000000000              printf@@GLIBC_2.2.5
0000000000000000       F *UND*    0000000000000000              __libc_start_main@@GLIBC_2.2.5
0000000000601028 g       .data    0000000000000000              __data_start
0000000000000000  w      *UND*    0000000000000000              __gmon_start__
0000000000400608 g     O .rodata    0000000000000000              .hidden __dso_handle
0000000000400600 g     O .rodata    0000000000000004              _IO_stdin_used
0000000000400580 g     F .text    0000000000000065              __libc_csu_init
0000000000601030 g       .bss    0000000000000000              _end
0000000000400430 g     F .text    0000000000000000              _start
000000000060102c g       .bss    0000000000000000              __bss_start
0000000000400531 g     F .text    000000000000004e              main
0000000000601030 g     O .data    0000000000000000              .hidden __TMC_END__
00000000004003c8 g     F .init    0000000000000000              _init
Disassembly of section .init:
00000000004003c8 <_init>:
_init():
  4003c8:    48 83 ec 08              sub    $0x8,%rsp
  4003cc:    48 8b 05 25 0c 20 00     mov    0x200c25(%rip),%rax        # 600ff8 <__gmon_start__>
  4003d3:    48 85 c0                 test   %rax,%rax
  4003d6:    74 05                    je     4003dd <_init+0x15>
  4003d8:    e8 43 00 00 00           callq  400420 <.plt.got>
  4003dd:    48 83 c4 08              add    $0x8,%rsp
  4003e1:    c3                       retq   
Disassembly of section .plt:
00000000004003f0 <.plt>:
  4003f0:    ff 35 12 0c 20 00        pushq  0x200c12(%rip)        # 601008 <_GLOBAL_OFFSET_TABLE_+0x8>
  4003f6:    ff 25 14 0c 20 00        jmpq   *0x200c14(%rip)        # 601010 <_GLOBAL_OFFSET_TABLE_+0x10>
  4003fc:    0f 1f 40 00              nopl   0x0(%rax)
0000000000400400 <printf@plt>:
  400400:    ff 25 12 0c 20 00        jmpq   *0x200c12(%rip)        # 601018 <printf@GLIBC_2.2.5>
  400406:    68 00 00 00 00           pushq  $0x0
  40040b:    e9 e0 ff ff ff           jmpq   4003f0 <.plt>
0000000000400410 <__libc_start_main@plt>:
  400410:    ff 25 0a 0c 20 00        jmpq   *0x200c0a(%rip)        # 601020 <__libc_start_main@GLIBC_2.2.5>
  400416:    68 01 00 00 00           pushq  $0x1
  40041b:    e9 d0 ff ff ff           jmpq   4003f0 <.plt>
Disassembly of section .plt.got:
0000000000400420 <.plt.got>:
  400420:    ff 25 d2 0b 20 00        jmpq   *0x200bd2(%rip)        # 600ff8 <__gmon_start__>
  400426:    66 90                    xchg   %ax,%ax
Disassembly of section .text:
0000000000400430 <_start>:
_start():
  400430:    31 ed                    xor    %ebp,%ebp
  400432:    49 89 d1                 mov    %rdx,%r9
  400435:    5e                       pop    %rsi
  400436:    48 89 e2                 mov    %rsp,%rdx
  400439:    48 83 e4 f0              and    $0xfffffffffffffff0,%rsp
  40043d:    50                       push   %rax
  40043e:    54                       push   %rsp
  40043f:    49 c7 c0 f0 05 40 00     mov    $0x4005f0,%r8
  400446:    48 c7 c1 80 05 40 00     mov    $0x400580,%rcx
  40044d:    48 c7 c7 31 05 40 00     mov    $0x400531,%rdi
  400454:    e8 b7 ff ff ff           callq  400410 <__libc_start_main@plt>
  400459:    f4                       hlt    
  40045a:    66 0f 1f 44 00 00        nopw   0x0(%rax,%rax,1)
0000000000400460 <deregister_tm_clones>:
deregister_tm_clones():
  400460:    b8 37 10 60 00           mov    $0x601037,%eax
  400465:    55                       push   %rbp
  400466:    48 2d 30 10 60 00        sub    $0x601030,%rax
  40046c:    48 83 f8 0e              cmp    $0xe,%rax
  400470:    48 89 e5                 mov    %rsp,%rbp
  400473:    77 02                    ja     400477 <deregister_tm_clones+0x17>
  400475:    5d                       pop    %rbp
  400476:    c3                       retq   
  400477:    b8 00 00 00 00           mov    $0x0,%eax
  40047c:    48 85 c0                 test   %rax,%rax
  40047f:    74 f4                    je     400475 <deregister_tm_clones+0x15>
  400481:    5d                       pop    %rbp
  400482:    bf 30 10 60 00           mov    $0x601030,%edi
  400487:    ff e0                    jmpq   *%rax
  400489:    0f 1f 80 00 00 00 00     nopl   0x0(%rax)
0000000000400490 <register_tm_clones>:
register_tm_clones():
  400490:    b8 30 10 60 00           mov    $0x601030,%eax
  400495:    55                       push   %rbp
  400496:    48 2d 30 10 60 00        sub    $0x601030,%rax
  40049c:    48 c1 f8 03              sar    $0x3,%rax
  4004a0:    48 89 e5                 mov    %rsp,%rbp
  4004a3:    48 89 c2                 mov    %rax,%rdx
  4004a6:    48 c1 ea 3f              shr    $0x3f,%rdx
  4004aa:    48 01 d0                 add    %rdx,%rax
  4004ad:    48 d1 f8                 sar    %rax
  4004b0:    75 02                    jne    4004b4 <register_tm_clones+0x24>
  4004b2:    5d                       pop    %rbp
  4004b3:    c3                       retq   
  4004b4:    ba 00 00 00 00           mov    $0x0,%edx
  4004b9:    48 85 d2                 test   %rdx,%rdx
  4004bc:    74 f4                    je     4004b2 <register_tm_clones+0x22>
  4004be:    5d                       pop    %rbp
  4004bf:    48 89 c6                 mov    %rax,%rsi
  4004c2:    bf 30 10 60 00           mov    $0x601030,%edi
  4004c7:    ff e2                    jmpq   *%rdx
  4004c9:    0f 1f 80 00 00 00 00     nopl   0x0(%rax)
00000000004004d0 <__do_global_dtors_aux>:
__do_global_dtors_aux():
  4004d0:    80 3d 55 0b 20 00 00     cmpb   $0x0,0x200b55(%rip)        # 60102c <_edata>
  4004d7:    75 11                    jne    4004ea <__do_global_dtors_aux+0x1a>
  4004d9:    55                       push   %rbp
  4004da:    48 89 e5                 mov    %rsp,%rbp
  4004dd:    e8 7e ff ff ff           callq  400460 <deregister_tm_clones>
  4004e2:    5d                       pop    %rbp
  4004e3:    c6 05 42 0b 20 00 01     movb   $0x1,0x200b42(%rip)        # 60102c <_edata>
  4004ea:    f3 c3                    repz retq 
  4004ec:    0f 1f 40 00              nopl   0x0(%rax)
00000000004004f0 <frame_dummy>:
frame_dummy():
  4004f0:    48 83 3d 28 09 20 00     cmpq   $0x0,0x200928(%rip)        # 600e20 <__JCR_END__>
  4004f7:    00 
  4004f8:    74 1e                    je     400518 <frame_dummy+0x28>
  4004fa:    b8 00 00 00 00           mov    $0x0,%eax
  4004ff:    48 85 c0                 test   %rax,%rax
  400502:    74 14                    je     400518 <frame_dummy+0x28>
  400504:    55                       push   %rbp
  400505:    bf 20 0e 60 00           mov    $0x600e20,%edi
  40050a:    48 89 e5                 mov    %rsp,%rbp
  40050d:    ff d0                    callq  *%rax
  40050f:    5d                       pop    %rbp
  400510:    e9 7b ff ff ff           jmpq   400490 <register_tm_clones>
  400515:    0f 1f 00                 nopl   (%rax)
  400518:    e9 73 ff ff ff           jmpq   400490 <register_tm_clones>
000000000040051d <add_a_and_b>:
add_a_and_b():
  40051d:    55                       push   %rbp
  40051e:    48 89 e5                 mov    %rsp,%rbp
  400521:    89 7d fc                 mov    %edi,-0x4(%rbp)
  400524:    89 75 f8                 mov    %esi,-0x8(%rbp)
  400527:    8b 45 f8                 mov    -0x8(%rbp),%eax
  40052a:    8b 55 fc                 mov    -0x4(%rbp),%edx
  40052d:    01 d0                    add    %edx,%eax
  40052f:    5d                       pop    %rbp
  400530:    c3                       retq   
0000000000400531 <main>:
main():
  400531:    55                       push   %rbp
  400532:    48 89 e5                 mov    %rsp,%rbp
  400535:    48 83 ec 20              sub    $0x20,%rsp
  400539:    89 7d ec                 mov    %edi,-0x14(%rbp)
  40053c:    48 89 75 e0              mov    %rsi,-0x20(%rbp)
  400540:    c7 45 fc 01 00 00 00     movl   $0x1,-0x4(%rbp)
  400547:    c7 45 f8 02 00 00 00     movl   $0x2,-0x8(%rbp)
  40054e:    8b 55 f8                 mov    -0x8(%rbp),%edx
  400551:    8b 45 fc                 mov    -0x4(%rbp),%eax
  400554:    89 d6                    mov    %edx,%esi
  400556:    89 c7                    mov    %eax,%edi
  400558:    e8 c0 ff ff ff           callq  40051d <add_a_and_b>
  40055d:    89 45 f4                 mov    %eax,-0xc(%rbp)
  400560:    8b 4d f4                 mov    -0xc(%rbp),%ecx
  400563:    8b 55 f8                 mov    -0x8(%rbp),%edx
  400566:    8b 45 fc                 mov    -0x4(%rbp),%eax
  400569:    89 c6                    mov    %eax,%esi
  40056b:    bf 10 06 40 00           mov    $0x400610,%edi
  400570:    b8 00 00 00 00           mov    $0x0,%eax
  400575:    e8 86 fe ff ff           callq  400400 <printf@plt>
  40057a:    8b 45 f4                 mov    -0xc(%rbp),%eax
  40057d:    c9                       leaveq 
  40057e:    c3                       retq   
  40057f:    90                       nop
0000000000400580 <__libc_csu_init>:
__libc_csu_init():
  400580:    41 57                    push   %r15
  400582:    41 89 ff                 mov    %edi,%r15d
  400585:    41 56                    push   %r14
  400587:    49 89 f6                 mov    %rsi,%r14
  40058a:    41 55                    push   %r13
  40058c:    49 89 d5                 mov    %rdx,%r13
  40058f:    41 54                    push   %r12
  400591:    4c 8d 25 78 08 20 00     lea    0x200878(%rip),%r12        # 600e10 <__frame_dummy_init_array_entry>
  400598:    55                       push   %rbp
  400599:    48 8d 2d 78 08 20 00     lea    0x200878(%rip),%rbp        # 600e18 <__init_array_end>
  4005a0:    53                       push   %rbx
  4005a1:    4c 29 e5                 sub    %r12,%rbp
  4005a4:    31 db                    xor    %ebx,%ebx
  4005a6:    48 c1 fd 03              sar    $0x3,%rbp
  4005aa:    48 83 ec 08              sub    $0x8,%rsp
  4005ae:    e8 15 fe ff ff           callq  4003c8 <_init>
  4005b3:    48 85 ed                 test   %rbp,%rbp
  4005b6:    74 1e                    je     4005d6 <__libc_csu_init+0x56>
  4005b8:    0f 1f 84 00 00 00 00     nopl   0x0(%rax,%rax,1)
  4005bf:    00 
  4005c0:    4c 89 ea                 mov    %r13,%rdx
  4005c3:    4c 89 f6                 mov    %r14,%rsi
  4005c6:    44 89 ff                 mov    %r15d,%edi
  4005c9:    41 ff 14 dc              callq  *(%r12,%rbx,8)
  4005cd:    48 83 c3 01              add    $0x1,%rbx
  4005d1:    48 39 eb                 cmp    %rbp,%rbx
  4005d4:    75 ea                    jne    4005c0 <__libc_csu_init+0x40>
  4005d6:    48 83 c4 08              add    $0x8,%rsp
  4005da:    5b                       pop    %rbx
  4005db:    5d                       pop    %rbp
  4005dc:    41 5c                    pop    %r12
  4005de:    41 5d                    pop    %r13
  4005e0:    41 5e                    pop    %r14
  4005e2:    41 5f                    pop    %r15
  4005e4:    c3                       retq   
  4005e5:    90                       nop
  4005e6:    66 2e 0f 1f 84 00 00     nopw   %cs:0x0(%rax,%rax,1)
  4005ed:    00 00 00 
00000000004005f0 <__libc_csu_fini>:
__libc_csu_fini():
  4005f0:    f3 c3                    repz retq 
Disassembly of section .fini:
00000000004005f4 <_fini>:
_fini():
  4005f4:    48 83 ec 08              sub    $0x8,%rsp
  4005f8:    48 83 c4 08              add    $0x8,%rsp
  4005fc:    c3                       retq

main函数

0000000000400531 <main>:
main():
  400531:    55                       push   %rbp
  400532:    48 89 e5                 mov    %rsp,%rbp
  400535:    48 83 ec 20              sub    $0x20,%rsp
  400539:    89 7d ec                 mov    %edi,-0x14(%rbp)
  40053c:    48 89 75 e0              mov    %rsi,-0x20(%rbp)
  400540:    c7 45 fc 01 00 00 00     movl   $0x1,-0x4(%rbp)
  400547:    c7 45 f8 02 00 00 00     movl   $0x2,-0x8(%rbp)
  40054e:    8b 55 f8                 mov    -0x8(%rbp),%edx
  400551:    8b 45 fc                 mov    -0x4(%rbp),%eax
  400554:    89 d6                    mov    %edx,%esi
  400556:    89 c7                    mov    %eax,%edi
  400558:    e8 c0 ff ff ff           callq  40051d <add_a_and_b>
  40055d:    89 45 f4                 mov    %eax,-0xc(%rbp)
  400560:    8b 4d f4                 mov    -0xc(%rbp),%ecx
  400563:    8b 55 f8                 mov    -0x8(%rbp),%edx
  400566:    8b 45 fc                 mov    -0x4(%rbp),%eax
  400569:    89 c6                    mov    %eax,%esi
  40056b:    bf 10 06 40 00           mov    $0x400610,%edi
  400570:    b8 00 00 00 00           mov    $0x0,%eax
  400575:    e8 86 fe ff ff           callq  400400 <printf@plt>
  40057a:    8b 45 f4                 mov    -0xc(%rbp),%eax
  40057d:    c9                       leaveq 
  40057e:    c3                       retq   
  40057f:    90                       nop

add函数

000000000040051d <add_a_and_b>:
add_a_and_b():
  40051d:    55                       push   %rbp
  40051e:    48 89 e5                 mov    %rsp,%rbp
  400521:    89 7d fc                 mov    %edi,-0x4(%rbp)
  400524:    89 75 f8                 mov    %esi,-0x8(%rbp)
  400527:    8b 45 f8                 mov    -0x8(%rbp),%eax
  40052a:    8b 55 fc                 mov    -0x4(%rbp),%edx
  40052d:    01 d0                    add    %edx,%eax
  40052f:    5d                       pop    %rbp
  400530:    c3                       retq