C源代码反汇编（Centos7）

川长思鸟来 2022-02-02 10:49 399阅读 0赞

### 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][20190511113657527.png]

#### 分析 ####

1.  执行gcc\_objdump文件，会得到 **1 + 1 = 2**； 执行指令是 **./gcc\_objdump**
2.  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**。
3.  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

[20190511113657527.png]: /images/20220202/71cbc9e9b9d848eab6457761350c68ef.png