VEH hook acceleration - c++

Question

I am trying to accelerate the speed of VEH hook. Veh hook class that I found from https://github.com/hoangprod/LeoSpecial-VEH-Hook/blob/master/LeoSpecial.h
#pragma once
#include <Windows.h>
#include <stdio.h>
#include <iostream>
#ifdef _WIN64
#define XIP Rip
#else
#define XIP Eip
#endif
class LeoHook {
public:
static bool Hook(uintptr_t og_fun, uintptr_t hk_fun);
static bool Unhook();
private:
static uintptr_t og_fun;
static uintptr_t hk_fun;
static PVOID VEH_Handle;
static DWORD oldProtection;
static bool AreInSamePage(const uint8_t* Addr1, const uint8_t* Addr2);
static LONG WINAPI LeoHandler(EXCEPTION_POINTERS *pExceptionInfo);
};
uintptr_t LeoHook::og_fun = 0;
uintptr_t LeoHook::hk_fun = 0;
PVOID LeoHook::VEH_Handle = nullptr;
DWORD LeoHook::oldProtection = 0;
bool LeoHook::Hook(uintptr_t original_fun, uintptr_t hooked_fun)
{
LeoHook::og_fun = original_fun;
LeoHook::hk_fun = hooked_fun;
//We cannot hook two functions in the same page, because we will cause an infinite callback
if (AreInSamePage((const uint8_t*)og_fun, (const uint8_t*)hk_fun))
return false;
//Register the Custom Exception Handler
VEH_Handle = AddVectoredExceptionHandler(true, (PVECTORED_EXCEPTION_HANDLER)LeoHandler);
//Toggle PAGE_GUARD flag on the page
if(VEH_Handle && VirtualProtect((LPVOID)og_fun, 1, PAGE_EXECUTE_READ | PAGE_GUARD, &oldProtection))
return true;
return false;
}
bool LeoHook::Unhook()
{
DWORD old;
if (VEH_Handle && //Make sure we have a valid Handle to the registered VEH
VirtualProtect((LPVOID)og_fun, 1, oldProtection, &old) && //Restore old Flags
RemoveVectoredExceptionHandler(VEH_Handle)) //Remove the VEH
return true;
return false;
}
LONG WINAPI LeoHook::LeoHandler(EXCEPTION_POINTERS *pExceptionInfo)
{
if (pExceptionInfo->ExceptionRecord->ExceptionCode == STATUS_GUARD_PAGE_VIOLATION) //We will catch PAGE_GUARD Violation
{
if (pExceptionInfo->ContextRecord->XIP == (uintptr_t)og_fun) //Make sure we are at the address we want within the page
{
pExceptionInfo->ContextRecord->XIP = (uintptr_t)hk_fun; //Modify EIP/RIP to where we want to jump to instead of the original function
}
pExceptionInfo->ContextRecord->EFlags |= 0x100; //Will trigger an STATUS_SINGLE_STEP exception right after the next instruction get executed. In short, we come right back into this exception handler 1 instruction later
return EXCEPTION_CONTINUE_EXECUTION; //Continue to next instruction
}
if (pExceptionInfo->ExceptionRecord->ExceptionCode == STATUS_SINGLE_STEP) //We will also catch STATUS_SINGLE_STEP, meaning we just had a PAGE_GUARD violation
{
DWORD dwOld;
VirtualProtect((LPVOID)og_fun, 1, PAGE_EXECUTE_READ | PAGE_GUARD, &dwOld); //Reapply the PAGE_GUARD flag because everytime it is triggered, it get removes
return EXCEPTION_CONTINUE_EXECUTION; //Continue the next instruction
}
return EXCEPTION_CONTINUE_SEARCH; //Keep going down the exception handling list to find the right handler IF it is not PAGE_GUARD nor SINGLE_STEP
}
bool LeoHook::AreInSamePage(const uint8_t* Addr1, const uint8_t* Addr2)
{
MEMORY_BASIC_INFORMATION mbi1;
if (!VirtualQuery(Addr1, &mbi1, sizeof(mbi1))) //Get Page information for Addr1
return true;
MEMORY_BASIC_INFORMATION mbi2;
if (!VirtualQuery(Addr2, &mbi2, sizeof(mbi2))) //Get Page information for Addr1
return true;
if (mbi1.BaseAddress == mbi2.BaseAddress) //See if the two pages start at the same Base Address
return true; //Both addresses are in the same page, abort hooking!
return false;
}
The hook is working fine without any problem. But it cost me a lot of FPS drop from a process that I injected. As I googled the most answer is saying reduce the amount of logic that have been use in hook. My hook method
__declspec(naked) void HookSend()
{
__asm
{
jmp dwAddress
}
}
As you see it doesn't have much logic that include in a function. But it still cost me a lot of fps.
The research number two is saying to copied all page function then modify the ASM of page function. But I have no idea how to copy a page function. So I need some guide how to copy a page function or another method to accelerate the VEH hook.
Thank you.