程序集传递函数指针 [英] Assembly pass pointer to function

问题描述

我正在尝试将DWORD变量作为指针参数发送给函数

I'm trying to sent DWORD variable into function as pointer paramater

variable1 dd 1
...
push [variable1]  ; push variable adress
call _InitPoiner
...
_InitPoiner:
    ;
    push ebp
    mov ebp, esp
    ;
    lea eax, [ebp+8]       ; load address
    mov dword [eax], 10    ; move value 10 into that address

    pop ebp
    ret
...
push [variable1]
push sdigit ; where sdigit db '%d', 0x0D, 0x0A, 0
call [printf]

但是variable1是1，而不是11，为什么?

but variable1 is 1, not 11 , why?

推荐答案

您确定要在完成后弹出变量吗?

You are making sure that you pop your vars when done?

以您的示例为例，我看不到该变量永远是11.在dd赋值处它从1开始，那么如果您的数学正确，那么它将是10.要通过调试器逐步执行此操作，可以检查lea / mov组合是否正常工作.无论哪种方式，我都希望1或10，而不是11.

Looking at your example, I see no way that the variable could ever be 11. It starts as 1 at the dd assignment, then if your math in the lea is correct, it would then be 10. If you were to step this through a debugger, you could check if your lea / mov combo is working right. Either way, I would expect 1 or 10, not 11.

也许您是要add而不是mov?

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