sys_clock_gettime
asmlinkage long sys_clock_gettime(clockid_t which_clock,
__SC_3264(__NR_clock_gettime, sys_clock_gettime32, sys_clock_gettime)
__SYSCALL(__NR_clock_gettime64, sys_clock_gettime)
__SC_3264(__NR_clock_gettime, sys_clock_gettime32, sys_clock_gettime)
__SYSCALL(__NR_clock_gettime64, sys_clock_gettime)
if (sys_clock_gettime(clock, &start) < 0) {
end_ret = sys_clock_gettime(clock, &end);