Hi, Simon

I compiled the kernel two times, one time with the original code and
one time with
#define container_of(ptr, type, member) ({			\
	(type *)( (char *)ptr - offsetof(type,member) );})

try with following version:

#define container_of(ptr, type, member) ({ \
	(type *)((char *)(ptr) - offsetof(type, member));})