Edit Question - KnowledgeHub

Title Body

#include <stdio.h> #define uint unsigned int #define AddressOfLabel(sectionname,out) __asm{mov [out],offset sectionname}; void* CreateFunction(void* start,void *end) { uint __start=(uint)start,__end=(uint)end-1 ,size,__func_runtime; void* func_runtime=malloc(size=(((__end)-(__start)))+1); __func_runtime=(uint)func_runtime; memcpy((void*)(__func_runtime),start,size); ((char*)func_runtime)[size]=0xC3; //ret return func_runtime; } void CallRuntimeFunction(void* address) { __asm { call address } } main() { void* _start,*_end; AddressOfLabel(__start,_start); AddressOfLabel(__end,_end); void* func = CreateFunction(_start,_end); CallRuntimeFunction(func); //I expected this method to print "Test" //but this method raised exception return 0; __start: printf("Test"); __end: } CreateFunction - takes two points in memory (function scope), allocate, copy it to the allocated memory and returns it (The void* used like a function to call with Assembly) CallRuntimeFunction - runs the functions that returns from CreateFunction #define AddressOfLabel(sectionname,out) - Outs the address of label (sectionname) to variable (out) When I debugged this code and stepped in the call of CallRuntimeFunction and go to disassembly , I saw alot of ??? instead of assembly code of between __start and __end labels. I tried to copy machine code between two labels and then run it. But I don't have any idea why I can't call function that allocated with malloc . Edit: I changed some code and done part of the work. Runtime Function's memory allocate: void* func_runtime=VirtualAlloc(0, size=(((__end)-(__start)))+1, MEM_COMMIT, PAGE_EXECUTE_READWRITE); Copy from function

Tags (comma-separated) Cancel