GDB无法访问内存我mmap

Question

在我的代码中，我映射了一些内存，可以从中读取和写入。出于某种原因，当我在gdb中运行代码时，gbd无法访问它。问题是什么？

有问题的代码

cout << "creating temp" << endl;
int *temp = mmap(... PROT_READ | PROT_WRITE ...);
*temp = 5;
cout << "temp = " << *temp << endl;

运行时的输出

creating temp
temp = 5

我的gdb提示

(gdb) n  
77        *temp = 5;  
(gdb) p temp  
$1 = (int *)0x7fffec4000;   
(gdb) x temp  
0x7fffec4000: cannot access memory at 0x7fffec4000  
(gdb) n  
78        cout << "temp = " << *temp << endl;
(gdb) x temp  
0x7fffec4000: cannot access memory at 0x7fffec4000
(gdb) n
temp = 5
(gdb) x temp  
0x7fffec4000: cannot access memory at 0x7fffec4000