Question

我正在研究PE Loader，就像windows loader

一样

我的目标是一个可执行文件而不是DLL，我尝试了第一个loadlibrary但遇到了重新分配问题，得到了一些代码来修复它，但是它不适用于所有目标（某些exe需要在同一个BaseAdress上加载才能工作）

所以我明白了，我要实现我的加载器以确保BaseAddress问题而不需要重新分配

我正在强制我的应用程序加载到高地址（0x10000000），同时使用VirtualAlloc为标题分配内存和目标应用的部分

我使用VirtualQuery来查看我想要分配的地址的状态，如果不是免费的话我使用UnMapViewOfFile如果页面类型为MEM_MAPPED，则为VirtualFree（MEM_RELEASE）

问题是如果内存页面是MEM_MAPPED＆amp; MEM_COMMIT（始终是页面文件支持的页面）所有方法都失败，错误代码为0x57 ERROR_INVALID_PARAMETER

在这里寻找解决方案/想法是代码：

MylpAddr = (DWORD)lpAddr ;
MemInfo.RegionSize = 0 ;
NtUnmapViewOfSection=       (NTUNMAPVIEWOFSECTION)GetProcAddress(LoadLibrary(TEXT("ntdll.dll")), "NtUnmapViewOfSection");
NtProtectVirtualMemory=     (NTPROTECTVIRTUALMEMORY)GetProcAddress(LoadLibrary(TEXT("ntdll.dll")), "NtProtectVirtualMemory");
NtUnlockVirtualMemory=      (NTUNLOCKVIRTUALMEMORY)GetProcAddress(LoadLibrary(TEXT("ntdll.dll")), "NtUnlockVirtualMemory");
GetSystemInfo(&siSysInfo);
szPage = siSysInfo.dwPageSize ;

i = VirtualQuery( (LPCVOID)MylpAddr , &MemInfo , 0x20 ) ;
if (!i) return NULL ;

if ( !(MemInfo.State & MEM_FREE) )
{
    if ( MemInfo.Type & MEM_MAPPED )
    {
        hProc = GetCurrentProcess() ;
        szPage = MemInfo.RegionSize ;
        i = NtUnlockVirtualMemory(hProc , (PVOID *)MemInfo.AllocationBase , (PULONG)szPage , LOCK_VM_IN_WORKING_SET | LOCK_VM_IN_RAM );
        i = NtProtectVirtualMemory(hProc , (PVOID *)MemInfo.AllocationBase , (PULONG)szPage , PAGE_READWRITE , &OldProt ) ;
        i = NtUnmapViewOfSection( hProc , (LPVOID)MemInfo.AllocationBase );
        i = UnmapViewOfFile( (LPVOID)MemInfo.AllocationBase );
        if (!i) i =1 ;
    }
    else
    {
        j = VirtualUnlock(MemInfo.BaseAddress , MemInfo.RegionSize);
        i = VirtualFree( (LPVOID)MemInfo.AllocationBase , NULL , MEM_RELEASE ) ;
    }
    if (!i) return NULL ;

}

MylpAddr = (DWORD)VirtualAlloc( lpAddr , dwSize , AllocType , ProtFlags );

Answer 1

很抱歉提出这么老的问题，我只是觉得这对某人有帮助。
据我所知，要分叉一个进程，你必须使用CreateProcess函数。因此，您需要使用VirtualQueryEx和VirtualAllocEx而不是VirtualQuery和VirtualAlloc。还可以使用创建过程的句柄替换hProc值。我还注意到你已明确使用0x20作为dwLength，你可能需要用dwSize来改变它。

总结：

PROCESS_INFORMATION piProcessInformation;
ZeroMemory(&piProcessInformation,sizeof(PROCESS_INFORMATION));
if(CreateProcess(NULL,processName,NULL,NULL,false,CREATE_SUSPENDED,NULL,NULL,&suStartUpInformation,&piProcessInformation))
{
            cContext.ContextFlags = CONTEXT_FULL;
            GetThreadContext(piProcessInformation.hThread,&cContext);
            i = VirtualQueryEx(piProcessInformation.hProcess, (LPCVOID)MylpAddr , &MemInfo , dwSize ) ;
            if (!i) return NULL ;

            if ( !(MemInfo.State & MEM_FREE) )
            {
                if ( MemInfo.Type & MEM_MAPPED )
                {
                    // hProc = GetCurrentProcess() ; No need to this line
                    szPage = MemInfo.RegionSize ;
                    i = NtUnlockVirtualMemory(piProcessInformation.hProcess , (PVOID *)MemInfo.AllocationBase , (PULONG)szPage , LOCK_VM_IN_WORKING_SET | LOCK_VM_IN_RAM );
                    i = NtProtectVirtualMemory(piProcessInformation.hProcess , (PVOID *)MemInfo.AllocationBase , (PULONG)szPage , PAGE_READWRITE , &OldProt ) ;
                    i = NtUnmapViewOfSection( piProcessInformation.hProcess , (LPVOID)MemInfo.AllocationBase );
                    i = UnmapViewOfFile( (LPVOID)MemInfo.AllocationBase );
                    if (!i) i =1 ;
                }
                else
                {
                    j = VirtualUnlock(MemInfo.BaseAddress , MemInfo.RegionSize);
                    i = VirtualFreeEx(piProcessInformation.hProcess, (LPVOID)MemInfo.AllocationBase , NULL , MEM_RELEASE ) ;
                }
                if (!i) return NULL ;

            }

            MylpAddr = (DWORD)VirtualAllocEx(piProcessInformation.hProcess, lpAddr , dwSize , AllocType , ProtFlags );
}

虚拟内存处理

1 个答案: