为什么“ gdb＆gt; disas /s main＆quot＆quot不告诉我源代码？

Question

我从二进制可执行文件开始，我想查看源代码，而不仅仅是汇编代码。这可能吗？ “ https://sourceware.org/gdb/onlinedocs/gdb/machine-code.html”的文档似乎生成源代码。
如果可能的话，为什么未显示源代码。我没有设置断点，代码没有条纹。我使用了GDB命令“ disas /s main”。屏幕截图从有关我的配置的一些信息开始。

──(root㉿kali)-[/home/kali/Downloads]
└─# uname -a
Linux kali 5.15.0-kali3-amd64 #1 SMP Debian 5.15.15-2kali1 (2022-01-31) x86_64 GNU/Linux
                                                                                                                                                                                             
┌──(root㉿kali)-[/home/kali/Downloads]
└─# gdb -v               
GNU gdb (Debian 10.1-2) 10.1.90.20210103-git
Copyright (C) 2021 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
                                                                                                                                                                                             
┌──(root㉿kali)-[/home/kali/Downloads]
└─# file RE1_64bit 
RE1_64bit: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.24, BuildID[sha1]=8616e4f2a4a3c325c2a1f32b8ebb8366694f7a03, not stripped
                                                                                                                                                                                             
┌──(root㉿kali)-[/home/kali/Downloads]
└─# gdb RE1_64bit 
GNU gdb (Debian 10.1-2) 10.1.90.20210103-git
Copyright (C) 2021 Free Software Foundation, Inc.                                                                                                                                            
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from RE1_64bit...
(No debugging symbols found in RE1_64bit)
(gdb) disas /s main
Dump of assembler code for function main:
   0x000000000040084e <+0>:     push   %rbp
   0x000000000040084f <+1>:     mov    %rsp,%rbp
   0x0000000000400852 <+4>:     sub    $0x40,%rsp
   0x0000000000400856 <+8>:     mov    %edi,-0x34(%rbp)
   0x0000000000400859 <+11>:    mov    %rsi,-0x40(%rbp)
   0x000000000040085d <+15>:    cmpl   $0x2,-0x34(%rbp)
   0x0000000000400861 <+19>:    je     0x400886 <main+56>
   0x0000000000400863 <+21>:    mov    -0x40(%rbp),%rax
   0x0000000000400867 <+25>:    mov    (%rax),%rax
   0x000000000040086a <+28>:    mov    %rax,%rsi
   0x000000000040086d <+31>:    mov    $0x4009a2,%edi
   0x0000000000400872 <+36>:    mov    $0x0,%eax
   0x0000000000400877 <+41>:    call   0x400580 <printf@plt>
   0x000000000040087c <+46>:    mov    $0x1,%edi
   0x0000000000400881 <+51>:    call   0x4005e0 <exit@plt>
   0x0000000000400886 <+56>:    mov    -0x40(%rbp),%rax
   0x000000000040088a <+60>:    add    $0x8,%rax
   0x000000000040088e <+64>:    mov    (%rax),%rax
   0x0000000000400891 <+67>:    mov    %rax,%rdi
   0x0000000000400894 <+70>:    call   0x400570 <strlen@plt>
   0x0000000000400899 <+75>:    cmp    $0x4,%rax
   0x000000000040089d <+79>:    je     0x4008c2 <main+116>
   0x000000000040089f <+81>:    mov    -0x40(%rbp),%rax
   0x00000000004008a3 <+85>:    mov    (%rax),%rax
   0x00000000004008a6 <+88>:    mov    %rax,%rsi
   0x00000000004008a9 <+91>:    mov    $0x4009a2,%edi
   0x00000000004008ae <+96>:    mov    $0x0,%eax
   0x00000000004008b3 <+101>:   call   0x400580 <printf@plt>
   0x00000000004008b8 <+106>:   mov    $0x1,%edi
   0x00000000004008bd <+111>:   call   0x4005e0 <exit@plt>
   0x00000000004008c2 <+116>:   movl   $0x0,-0x4(%rbp)
   0x00000000004008c9 <+123>:   mov    $0x4009b3,%edi
   0x00000000004008ce <+128>:   mov    $0x0,%eax
   0x00000000004008d3 <+133>:   call   0x400580 <printf@plt>
   0x00000000004008d8 <+138>:   lea    -0x30(%rbp),%rax
   0x00000000004008dc <+142>:   mov    %rax,%rdi
   0x00000000004008df <+145>:   call   0x4005d0 <gets@plt>
   0x00000000004008e4 <+150>:   cmpl   $0x0,-0x4(%rbp)
   0x00000000004008e8 <+154>:   je     0x4008f8 <main+170>
   0x00000000004008ea <+156>:   mov    -0x40(%rbp),%rax
   0x00000000004008ee <+160>:   mov    %rax,%rdi
   0x00000000004008f1 <+163>:   call   0x4006dd <fg>
   0x00000000004008f6 <+168>:   jmp    0x400902 <main+180>
   0x00000000004008f8 <+170>:   mov    $0x4009cd,%edi
   0x00000000004008fd <+175>:   call   0x400560 <puts@plt>
   0x0000000000400902 <+180>:   mov    $0x0,%eax
   0x0000000000400907 <+185>:   leave  
   0x0000000000400908 <+186>:   ret    
End of assembler dump.

Answer 1

正如评论中所述，这一行：

(No debugging symbols found in RE1_64bit)

表明二进制文件不包含任何调试信息，因此您将无法将汇编代码与源线匹配。

如果二进制文件确实包含调试信息，则仅包含二进制文件中的表映射地址，以文件名和行号。您仍然需要拥有实际的源文件才能查看源线，当然，源文件需要是编译到该特定二进制中的确切版本，否则调试信息中的行号将不会正确匹配。