在内存中执行机器代码 [英] Executing machine code in memory

问题描述

我想知道如何执行存储在内存中的机器码。

I'm trying to figure out how to execute machine code stored in memory.

我有以下代码：

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char* argv[])
{
    FILE* f = fopen(argv[1], "rb");

    fseek(f, 0, SEEK_END);
    unsigned int len = ftell(f);
    fseek(f, 0, SEEK_SET);

    char* bin = (char*)malloc(len);
    fread(bin, 1, len, f);

    fclose(f);

    return ((int (*)(int, char *)) bin)(argc-1, argv[1]);
}

上面的代码在GCC中编译正常，但是当我尝试并执行程序从命令行如下：

The code above compiles fine in GCC, but when I try and execute the program from the command line like this:

./my_prog /bin/echo hello

程序segfaults。我发现问题是在最后一行，因为注释它停止了segfault。

The program segfaults. I've figured out the problem is on the last line, as commenting it out stops the segfault.

我不认为我做的很对，

I don't think I'm doing it quite right, as I'm still getting my head around function pointers.

这个问题是错误的转换还是别的什么？

Is the problem a faulty cast, or something else?

推荐答案

在我看来你正在加载一个ELF图像，然后试图直接跳进ELF标题？ http://en.wikipedia.org/wiki/Executable_and_Linkable_Format

It seems to me you're loading an ELF image and then trying to jump straight into the ELF header? http://en.wikipedia.org/wiki/Executable_and_Linkable_Format

如果你试图执行另一个二进制文件，你为什么不使用你使用的平台的进程创建函数？

If you're trying to execute another binary, why don't you use the process creation functions for whichever platform you're using?

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