#define _CHECKMEMOVERFLOW_H_
#define CHECK_MEM_OVERFLOW
#ifdef CHECK_MEM_OVERFLOW
//鎿嶄綔緋葷粺鍐呭瓨鍒嗛厤綺掑害涓洪〉闈紙4K錛?/span>
#define PAGE_SIZE 4096
#define PLATFORM_WIN32
#ifdef PLATFORM_WIN32
#include <stdlib.h>
#include <windows.h>
/*
* oooooooo
ooooo | ********
(*)acture memory pages | protect page*/
inline void * operator new (size_t size)
{
size_t page_num = (size_t)(size / PAGE_SIZE);
size_t offset = 0;
if(0 != (size % PAGE_SIZE))
{
page_num++;
offset = PAGE_SIZE - size % PAGE_SIZE;
}
void *p = VirtualAlloc(NULL,page_num*PAGE_SIZE+1,MEM_COMMIT,PAGE_READWRITE);
void *pchecker = (char*)p + page_num*PAGE_SIZE;
DWORD old_value;
VirtualProtect(pchecker,PAGE_SIZE,PAGE_NOACCESS,&old_value);
return (char *)p + offset;
}
inline void operator delete(void *p)
{
void* address = (char *)p - (size_t)(p) % PAGE_SIZE;
VirtualFree(address,0,MEM_RELEASE);
}
#else
#include <stdlib.h>
#include <sys/mman.h>
#include <stdio.h>
/*
* ********* |oooooooooooooooo
ooooo | ************ size page |
(*)acture memory pages | protect page*/
//gcc : connot be inline
void * operator new (size_t size)
{
//calc page num and offset
int page_num = (int)(size / PAGE_SIZE + 1);
size_t offset = page_num * PAGE_SIZE - size;
//alloc memory pages
void *p = mmap(NULL,page_num*PAGE_SIZE+2,PROT_READ|PROT_WRITE,MAP_PRIVATE | MAP_ANON, -1, 0);
//saved page num
size_t* pSize = (size_t*)((char*)p+PAGE_SIZE-sizeof(size_t));
*pSize = page_num+2;
mprotect(p, PAGE_SIZE, PROT_NONE);
//set memory overflow protect page
void *pchecker = (char*)p + page_num*PAGE_SIZE;
mprotect(pchecker, PAGE_SIZE, PROT_NONE);
return (char *)p + offset;
}
void operator delete(void *p)
{
//calc acture memory page start address
void* address = (char *)p - (size_t)p % PAGE_SIZE;
mprotect((char*)address-PAGE_SIZE, PAGE_SIZE, PROT_READ);
size_t pagenum = (size_t)*((char*)address-sizeof(size_t));
munmap((char*)address-PAGE_SIZE, pagenum*PAGE_SIZE);
}
#endif
#endif
//#define TEST_OVERFLOW
#ifdef TEST_OVERFLOW
#include <stdio.h>
int main(int argc,char *argv[])
{
printf("test start
\n");char * a = new char[12340];
printf("%c\n",a[12340]); //紼嬪簭榪愯鍒拌繖閲屽皢鍑虹幇debug涓柇
delete[] a;
printf("test done
\n");return 0;
}
#endif
#endif
鍘熺悊錛?/p>
1錛岄噸杞藉叏灞new/delete錛屾帴綆″唴瀛樼敵璇?閲婃斁錛?/p>
2.a錛屽湪windows涓嬶紝欏甸潰鏈灝忓垎閰嶅崟浣嶄負4K錛岃皟鐢╒irtualAlloc鍒嗛厤鍐呭瓨錛屽茍鍦ㄦ渶鍚庝竴涓〉闈㈠悗闈㈡坊鍔犱竴涓?#8220;鍝ㄥ叺”欏甸潰錛岄〉闈㈠睘鎬т負NOACCESS錛岃鍐欒欏甸潰鍧嘽rash錛?/p>
2.b錛屽湪linux涓嬶紝鍘熺悊鍚屼笂錛屼絾蹇呴』鍦ㄧ敵璇風殑鍐呭瓨鍓嶉潰澶氱敵璇蜂竴涓〉闈繚瀛樼敵璇風殑欏甸潰鏁幫紱
娉ㄦ剰錛?/p>
鍙兘鍦–++涓嬌鐢紝windows/mac涓嬫祴璇曢氳繃銆?/p>
浣跨敤鏂規(guī)硶錛?br />
鍙include榪欎釜澶存枃浠跺嵆鍙紝涓斿唴瀛樺繀欏繪槸new鍑烘潵鐨勶紝鑰岄潪malloc鐨勩?/p>
鍙傝冿細
1錛宧ttp://www.wangchao.net.cn/bbsdetail_65784.html
2錛宧ttp://blog.csdn.net/cjfeii/article/details/9122279
]]>