使用XCode 4.6在MacOSX 10.8.2下編寫mmap將導致程序崩潰

我嘗試使用XCode 4.6在MacOSX 10.8.2下運行一個簡單的mmap測試。該程序如下，映射爲讀取的文件是OK的，而對寫入指針「target」的訪問會使程序崩潰。錯誤消息是「EXC_BAD_ACCESS」。使用XCode 4.6在MacOSX 10.8.2下編寫mmap將導致程序崩潰

有沒有人與我有同樣的情況？非常感謝。

#include <stdio.h> 
#include <string.h> 
#include <sys/mman.h> 
#include <fcntl.h> 
#include <unistd.h> 
int main(int argc, const char * argv[]) { 
int input, output; 
size_t size; 

char *source, *target; 

input = open("SEK2.txt", O_RDONLY); 
if (input == -1) { 
    printf("Open source file failed"); 
    return -1; 
} 
output = open("test.txt", O_RDWR|O_CREAT|O_TRUNC); 
if (output == -1) { 
    printf("Open Output file failed"); 
    return -1; 
} 

size = lseek(input, 0, SEEK_END); 
printf("File size = %d\n", size); 

source = (char*)mmap(0, size, PROT_READ, MAP_PRIVATE, input, 0); 
if (source == (void*)-1) { 
    printf("Source MMap Error\n"); 
    return -1; 
} 

target = (char*)mmap(0, size, PROT_EXEC, MAP_PRIVATE, output, 0); 
if (target == (void*)-1) { 
    printf("Target MMap Error\n"); 
    return -1; 
} 

memcpy(target, source, size); // EXC_BAD_ACCESS to "target" 
munmap(source, size); 
munmap(target, size); 

close(input); 
close(output); 

printf("Successed"); 
return 0;

}

來源

2013-04-27 user2327236