面试的过程中,container_of的实现很重要:
#define container_of(ptr, type, member) ({ \
const typeof( ((type *)0)->member ) *__mptr = (ptr); \
(type *)( (char *)__mptr - offsetof(type,member) );})
offserof:
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)