static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, const struct itimerval *const value, struct itimerval *const ovalue) { u64 oval, nval, ointerval, ninterval; struct cpu_itimer *it = &tsk->signal->it[clock_id]; /* * Use the to_ktime conversion because that clamps the maximum * value to KTIME_MAX and avoid multiplication overflows. */ nval = ktime_to_ns(timeval_to_ktime(value->it_value)); ninterval = ktime_to_ns(timeval_to_ktime(value->it_interval)); spin_lock_irq(&tsk->sighand->siglock); oval = it->expires; ointerval = it->incr; if (oval || nval) { if (nval > 0) nval += TICK_NSEC; set_process_cpu_timer(tsk, clock_id, &nval, &oval); } it->expires = nval; it->incr = ninterval; trace_itimer_state(clock_id == CPUCLOCK_VIRT ? ITIMER_VIRTUAL : ITIMER_PROF, value, nval); spin_unlock_irq(&tsk->sighand->siglock); if (ovalue) { ovalue->it_value = ns_to_timeval(oval); ovalue->it_interval = ns_to_timeval(ointerval); } }
int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue) { struct task_struct *tsk = current; struct hrtimer *timer; ktime_t expires; /* * Validate the timevals in value. */ if (!timeval_valid(&value->it_value) || !timeval_valid(&value->it_interval)) return -EINVAL; trace_timer_itimer_set(which, value); switch (which) { case ITIMER_REAL: again: spin_lock_irq(&tsk->sighand->siglock); timer = &tsk->signal->real_timer; if (ovalue) { ovalue->it_value = itimer_get_remtime(timer); ovalue->it_interval = ktime_to_timeval(tsk->signal->it_real_incr); } /* We are sharing ->siglock with it_real_fn() */ if (hrtimer_try_to_cancel(timer) < 0) { spin_unlock_irq(&tsk->sighand->siglock); goto again; } expires = timeval_to_ktime(value->it_value); if (expires.tv64 != 0) { tsk->signal->it_real_incr = timeval_to_ktime(value->it_interval); hrtimer_start(timer, expires, HRTIMER_MODE_REL); } else tsk->signal->it_real_incr.tv64 = 0; trace_itimer_state(ITIMER_REAL, value, 0); spin_unlock_irq(&tsk->sighand->siglock); break; case ITIMER_VIRTUAL: set_cpu_itimer(tsk, CPUCLOCK_VIRT, value, ovalue); break; case ITIMER_PROF: set_cpu_itimer(tsk, CPUCLOCK_PROF, value, ovalue); break; default: return -EINVAL; } return 0; }
static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, const struct itimerval *const value, struct itimerval *const ovalue) { cputime_t cval, nval, cinterval, ninterval; s64 ns_ninterval, ns_nval; u32 error, incr_error; struct cpu_itimer *it = &tsk->signal->it[clock_id]; nval = timeval_to_cputime(&value->it_value); ns_nval = timeval_to_ns(&value->it_value); ninterval = timeval_to_cputime(&value->it_interval); ns_ninterval = timeval_to_ns(&value->it_interval); error = cputime_sub_ns(nval, ns_nval); incr_error = cputime_sub_ns(ninterval, ns_ninterval); spin_lock_irq(&tsk->sighand->siglock); cval = it->expires; cinterval = it->incr; if (!cputime_eq(cval, cputime_zero) || !cputime_eq(nval, cputime_zero)) { if (cputime_gt(nval, cputime_zero)) nval = cputime_add(nval, cputime_one_jiffy); set_process_cpu_timer(tsk, clock_id, &nval, &cval); } it->expires = nval; it->incr = ninterval; it->error = error; it->incr_error = incr_error; trace_itimer_state(clock_id == CPUCLOCK_VIRT ? ITIMER_VIRTUAL : ITIMER_PROF, value, nval); spin_unlock_irq(&tsk->sighand->siglock); if (ovalue) { cputime_to_timeval(cval, &ovalue->it_value); cputime_to_timeval(cinterval, &ovalue->it_interval); } }