如何longjmp的工作? [英] How does longjmp work?
本文介绍了如何longjmp的工作?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我需要了解如何longjmp函数工程;我知道它做什么,但我需要知道它是怎么做的。
I need to understand HOW longjmp function works; I know what it does, but I need to know how it does it.
我试图disas在GDB中code,但我不明白一些步骤。在code是:
I tried to disas the code in gdb but I can't understand some steps. The code is:
0xb7ead420 <siglongjmp+0>: push %ebp
0xb7ead421 <siglongjmp+1>: mov %esp,%ebp
0xb7ead423 <siglongjmp+3>: sub $0x18,%esp
0xb7ead426 <siglongjmp+6>: mov %ebx,-0xc(%ebp)
0xb7ead429 <siglongjmp+9>: call 0xb7e9828f <_Unwind_Find_FDE@plt+119>
0xb7ead42e <siglongjmp+14>: add $0x12bbc6,%ebx
0xb7ead434 <siglongjmp+20>: mov %esi,-0x8(%ebp)
0xb7ead437 <siglongjmp+23>: mov 0xc(%ebp),%esi
0xb7ead43a <siglongjmp+26>: mov %edi,-0x4(%ebp)
0xb7ead43d <siglongjmp+29>: mov 0x8(%ebp),%edi
0xb7ead440 <siglongjmp+32>: mov %esi,0x4(%esp)
0xb7ead444 <siglongjmp+36>: mov %edi,(%esp)
0xb7ead447 <siglongjmp+39>: call 0xb7ead4d0
0xb7ead44c <siglongjmp+44>: mov 0x18(%edi),%eax
0xb7ead44f <siglongjmp+47>: test %eax,%eax
0xb7ead451 <siglongjmp+49>: jne 0xb7ead470 <siglongjmp+80>
0xb7ead453 <siglongjmp+51>: test %esi,%esi
0xb7ead455 <siglongjmp+53>: mov $0x1,%eax
0xb7ead45a <siglongjmp+58>: cmove %eax,%esi
0xb7ead45d <siglongjmp+61>: mov %esi,0x4(%esp)
0xb7ead461 <siglongjmp+65>: mov %edi,(%esp)
0xb7ead464 <siglongjmp+68>: call 0xb7ead490
0xb7ead469 <siglongjmp+73>: lea 0x0(%esi,%eiz,1),%esi
0xb7ead470 <siglongjmp+80>: lea 0x1c(%edi),%eax
0xb7ead473 <siglongjmp+83>: movl $0x0,0x8(%esp)
0xb7ead47b <siglongjmp+91>: mov %eax,0x4(%esp)
0xb7ead47f <siglongjmp+95>: movl $0x2,(%esp)
0xb7ead486 <siglongjmp+102>: call 0xb7ead890 <sigprocmask>
0xb7ead48b <siglongjmp+107>: jmp 0xb7ead453 <siglongjmp+51>
有人能简单介绍一下我的code,或说明在哪里可以找到系统中的源$ C $ C?
Can someone briefly explain me the code, or indicate where I can find the source code in the system?
推荐答案
下面是的longjmp
的I386 code,在标准的i386 ABI,没有任何疯狂扩展使用C ++,异常,清理功能,信号屏蔽等互动:
Here is the i386 code for longjmp
, in the standard i386 ABI, without any crazy extensions for interaction with C++, exceptions, cleanup functions, signal mask, etc.:
mov 4(%esp),%edx
mov 8(%esp),%eax
test %eax,%eax
jnz 1f
inc %eax
1:
mov (%edx),%ebx
mov 4(%edx),%esi
mov 8(%edx),%edi
mov 12(%edx),%ebp
mov 16(%edx),%ecx
mov %ecx,%esp
mov 20(%edx),%ecx
jmp *%ecx
这篇关于如何longjmp的工作?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文