可以32bit gdb调试64bit二进制文件吗？

Question

32bit gdb debug 64bit二进制文件？

Answer 1

是的。至少在最新版本上，32位gdb在Solaris上很好地调试了64位二进制文​​件。

$ cat /etc/release 
         Oracle Solaris 11 Express snv_151a X86 
    Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved. 
          Assembled 04 November 2010 
$ file /usr/bin/gdb 
/usr/bin/gdb: ELF 32-bit LSB executable 80386 Version 1 [FPU], dynamically linked, not stripped, no debugging information available 
$ file a 
a:    ELF 64-bit LSB executable AMD64 Version 1, dynamically linked, not stripped 
$ gdb a         
GNU gdb 6.8 
Copyright (C) 2008 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 "i386-pc-solaris2.11"... 
(gdb) b main 
Breakpoint 1 at 0x400e9c: file a.c, line 3. 
(gdb) run 
Starting program: /tmp/a 

Breakpoint 1, main() at a.c:3 
3    printf("hello world !"); 
(gdb) quit 
The program is running. Exit anyway? (y or n) y 
$ 

但是，如果你仔细看，这32 GDB的引擎盖下推出了64位GDB：

$ truss -f -t execve /usr/bin/gdb a 
1793: execve("/usr/bin/gdb", 0x0804755C, 0x08047568) argc = 2 
1793: execve("/usr/bin/amd64/gdb", 0x0804755C, 0x08047568) argc = 2 
GNU gdb 6.8 
Copyright (C) 2008 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 "i386-pc-solaris2.11"... 
(gdb) 

它做它无论调试的二进制是32位还是64位。

我仍然认为调试器与Solaris下的进程交互的方式与尺寸无关，因此从技术上讲，只有32位二进制调试器应该能够调试64位程序。

64位gdb能够调试32位和64位二进制文​​件，但32位gdb无法调试64位二进制文​​件。这就是你正在经历的。

Answer 2

以上答案不正确。您需要一个64位调试器来调试64位进程。这正是gdb为什么在后台分配64位副本的原因。