make: Entering directory `/usr/src/linux-headers-4.4.0-142-generic'
  CC [M]  /home/user/kernrk/kernrk.o
/home/user/kernrk/kernrk.c:11:8: error: redefinition of ‘struct linux_dirent64’
 struct linux_dirent64 {
        ^
In file included from /home/user/kernrk/kernrk.c:5:0:
include/linux/dirent.h:4:8: note: originally defined here
 struct linux_dirent64 {
        ^
/home/user/kernrk/kernrk.c: In function ‘getdents_post_handler’:
/home/user/kernrk/kernrk.c:28:17: error: ‘struct pt_regs’ has no member named ‘rax’
     nread = regs->rax;
                 ^
/home/user/kernrk/kernrk.c:32:50: error: ‘struct pt_regs’ has no member named ‘rdi’
     dirent = (struct linux_dirent64 __user *)regs->rdi;
                                                  ^
/home/user/kernrk/kernrk.c:57:9: error: ‘struct pt_regs’ has no member named ‘rax’
     regs->rax = new_nread;
         ^