（六）linux内核中的offsetof与container_of宏

参考：

• offsetof与container_of宏[总结]

#define offsetof(type, member) (size_t)&(((type*)0)->member)


#define container_of(ptr, type, member) ({ \
     const typeof( ((type *)0)->member ) *__mptr = (ptr); \
     (type *)( (char *)__mptr - offsetof(type,member) );})