滴水中级班保护模式阶段测试作业

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// 保护模式阶段测试第一题.cpp : Defines the entry point for the console application.
//

1给定一个线性地址，长度，读取内容

2-9-9-12

#include "stdafx.h"
#include <Windows.h>
typedef struct PAGE{
   DWORD PTELinkAddress;
   DWORD PDELinkAddress;
   DWORD PTELow;
   DWORD PDELow;
};
char Buf[6];
PAGE Page;
void _declspec(naked) print(){
   __asm{

       pushad
       pushf
       mov eax,dword ptr ds:[Page.PTELinkAddress]
       mov eax,dword ptr ds:[eax]
       mov dword ptr ds:[Page.PTELow],eax
       mov eax,dword ptr ds:[Page.PDELinkAddress]
       mov eax,dword ptr ds:[eax]
       mov dword ptr ds:[Page.PDELow],eax
       popf
       popad
       retf
   }
}
void Init(int LinkAddress){

   Page.PDELinkAddress=0xC0600000+((LinkAddress>>18)&0x3ff8);
   Page.PTELinkAddress=0xC0000000+((LinkAddress>>9)&0x7ffff8);
}
int MmIsAddressValid(int LinkAddress){
   Init(LinkAddress);
   __asm{
       call fword ptr Buf;
   }
   if(0==Page.PDELow&0x1){   //PDE p位为1PTT无效
       return 0;
   }
   if(0==Page.PTELow*0x1){   //PTE p位为1物理页无效
       return 0;
   }
   return true;
}
int ReadMemory(void* SrcAddress,DWORD DestAddresss,DWORD size){
   int cout=((int)DestAddresss)%0x1000;
   if(cout+size<=0x1000){               //访问的数据在一个物理页
       if(0==MmIsAddressValid(((int)DestAddresss)&0xfffff000)){
           return 0;
       }
       memcpy(SrcAddress,(void*)DestAddresss,size);
   }
   else{                               //访问的数据长度不在一个物理页上
       int n=(cout+size)/0x1000+1;       //需要访问这么多个页才能知道有没有内存能不能读
       int RoundAddress=(((int)DestAddresss)&0xfffff000);
       for(int i=0;i<n;i++){
           if(0==MmIsAddressValid(((int)RoundAddress))){
               return 0;               //只要有一个页没有挂物理页就返回失败
           }
           RoundAddress+=0x1000;
       }
       memcpy(SrcAddress,(void*)DestAddresss,size);
   }
   return 1;
}
int main(int argc, char* argv[])
{
   int* P=(int*)VirtualAlloc(NULL,0x1000,MEM_RESERVE | MEM_COMMIT,PAGE_READWRITE);
   *((WORD*)&Buf[4])=0x48;
   printf("%p\n",print);
   if(0==ReadMemory((void*)P,0x300000,0x1000)){
       MessageBox(0,0,"读取内存失败",0);
   }

printf("Hello World!\n");
return 0;
}

保护模式阶段测试第二题

#include "stdafx.h"
#include <Windows.h>
#define SRCADDRESS 0x1000
typedef struct PAGE{
   DWORD SrcLinkAddress;
   DWORD DestLinkAddress;       //把目标地址线性的物理页挂到原线性地址的屋里也出
   DWORD DestPDELinkAddress;
   DWORD DestPTELinkAddress;
   DWORD SrcPDELinkAddress;
   DWORD SrcPTELinkAddress;
};
PAGE Page;
void Init(int* P){
   Page.SrcLinkAddress=SRCADDRESS;
   Page.DestLinkAddress=(int)P;
   int a=(((Page.DestLinkAddress)>>18)&0x3ff8);
   Page.DestPDELinkAddress=0xC0600000+((Page.DestLinkAddress>>18)&0x3ff8);
   Page.DestPTELinkAddress=0xC0000000+((Page.DestLinkAddress>>9)&0x7ffff8);
   Page.SrcPDELinkAddress=0xC0600000+((Page.SrcLinkAddress>>18)&0x3ff8);
   Page.SrcPTELinkAddress=0xC0000000+((0x1000>>9)&0x7ffff8);
}//0001 000 0 0000 0000

void _declspec(naked) print(){
   __asm{

       pushad
       mov edx,dword ptr ds:[Page.SrcPDELinkAddress]       //原地址PDE的p位判断是否有
       and edx,0x1
       jne taolaod                                       //P位不等于0

       //如果把0x1000的PDE了会改变 2MB线性地址的物理页全都错乱
       //如果VirtualAlloc分配的地址是上下有2GB线性地址没有挂需要给src的线性地址挂上PTE
       //这里面是给0x1000线性地址如果该PDE堆栈就挂了 ring3堆栈就挂了 0x1000线性地址与ring3堆栈公有一个PTE，我曾经吃过亏
taolaod:
       mov eax,dword ptr ds:[Page.DestPTELinkAddress]
       mov ecx,dword ptr ds:[eax]
       mov eax,dword ptr ds:[eax+4]

       mov edx,ds:[Page.SrcPTELinkAddress]
       mov dword ptr ds:[edx],ecx
       mov dword ptr ds:[edx+4],eax
       popad
       retf
   }
}
int main(int argc, char* argv[])
{
   int i=0;
   char Buf[6];
   int* P=(int*)VirtualAlloc(NULL,0x1000,MEM_RESERVE | MEM_COMMIT,PAGE_READWRITE);
   if(NULL==P){
       MessageBox(NULL,0,"VirtualAlloc开辟内存失败",0);
   }
   for(i=0;i<100;i++){
       P[i]=(int)(P+i);
   }
   Init(P);
   *((WORD*)&Buf[4])=0x48;
   printf("%p\n",print);
   int c=0;
   __asm{
       call fword ptr Buf;
   }
   int *a=(int*)0x1000;
   for(i=0;i<100;i++){
       if(i%5){
           printf("%p\t",a[i]);
       }else{
           printf("\n");
       }
   }
   printf("Hello World!\n");
   return 0;
}