--- /dev/null
+/*
+ * Implement CPU time clocks for the POSIX clock interface.
+ */
+
+#include <linux/sched.h>
+#include <linux/sched/rt.h>
+#include <linux/posix-timers.h>
+#include <linux/errno.h>
+#include <linux/math64.h>
+#include <asm/uaccess.h>
+#include <linux/kernel_stat.h>
+#include <trace/events/timer.h>
+#include <linux/random.h>
+#include <linux/tick.h>
+#include <linux/workqueue.h>
+
+/*
+ * Called after updating RLIMIT_CPU to run cpu timer and update
+ * tsk->signal->cputime_expires expiration cache if necessary. Needs
+ * siglock protection since other code may update expiration cache as
+ * well.
+ */
+void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new)
+{
+ cputime_t cputime = secs_to_cputime(rlim_new);
+
+ spin_lock_irq(&task->sighand->siglock);
+ set_process_cpu_timer(task, CPUCLOCK_PROF, &cputime, NULL);
+ spin_unlock_irq(&task->sighand->siglock);
+}
+
+static int check_clock(const clockid_t which_clock)
+{
+ int error = 0;
+ struct task_struct *p;
+ const pid_t pid = CPUCLOCK_PID(which_clock);
+
+ if (CPUCLOCK_WHICH(which_clock) >= CPUCLOCK_MAX)
+ return -EINVAL;
+
+ if (pid == 0)
+ return 0;
+
+ rcu_read_lock();
+ p = find_task_by_vpid(pid);
+ if (!p || !(CPUCLOCK_PERTHREAD(which_clock) ?
+ same_thread_group(p, current) : has_group_leader_pid(p))) {
+ error = -EINVAL;
+ }
+ rcu_read_unlock();
+
+ return error;
+}
+
+static inline unsigned long long
+timespec_to_sample(const clockid_t which_clock, const struct timespec *tp)
+{
+ unsigned long long ret;
+
+ ret = 0; /* high half always zero when .cpu used */
+ if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
+ ret = (unsigned long long)tp->tv_sec * NSEC_PER_SEC + tp->tv_nsec;
+ } else {
+ ret = cputime_to_expires(timespec_to_cputime(tp));
+ }
+ return ret;
+}
+
+static void sample_to_timespec(const clockid_t which_clock,
+ unsigned long long expires,
+ struct timespec *tp)
+{
+ if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED)
+ *tp = ns_to_timespec(expires);
+ else
+ cputime_to_timespec((__force cputime_t)expires, tp);
+}
+
+/*
+ * Update expiry time from increment, and increase overrun count,
+ * given the current clock sample.
+ */
+static void bump_cpu_timer(struct k_itimer *timer,
+ unsigned long long now)
+{
+ int i;
+ unsigned long long delta, incr;
+
+ if (timer->it.cpu.incr == 0)
+ return;
+
+ if (now < timer->it.cpu.expires)
+ return;
+
+ incr = timer->it.cpu.incr;
+ delta = now + incr - timer->it.cpu.expires;
+
+ /* Don't use (incr*2 < delta), incr*2 might overflow. */
+ for (i = 0; incr < delta - incr; i++)
+ incr = incr << 1;
+
+ for (; i >= 0; incr >>= 1, i--) {
+ if (delta < incr)
+ continue;
+
+ timer->it.cpu.expires += incr;
+ timer->it_overrun += 1 << i;
+ delta -= incr;
+ }
+}
+
+/**
+ * task_cputime_zero - Check a task_cputime struct for all zero fields.
+ *
+ * @cputime: The struct to compare.
+ *
+ * Checks @cputime to see if all fields are zero. Returns true if all fields
+ * are zero, false if any field is nonzero.
+ */
+static inline int task_cputime_zero(const struct task_cputime *cputime)
+{
+ if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime)
+ return 1;
+ return 0;
+}
+
+static inline unsigned long long prof_ticks(struct task_struct *p)
+{
+ cputime_t utime, stime;
+
+ task_cputime(p, &utime, &stime);
+
+ return cputime_to_expires(utime + stime);
+}
+static inline unsigned long long virt_ticks(struct task_struct *p)
+{
+ cputime_t utime;
+
+ task_cputime(p, &utime, NULL);
+
+ return cputime_to_expires(utime);
+}
+
+static int
+posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp)
+{
+ int error = check_clock(which_clock);
+ if (!error) {
+ tp->tv_sec = 0;
+ tp->tv_nsec = ((NSEC_PER_SEC + HZ - 1) / HZ);
+ if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
+ /*
+ * If sched_clock is using a cycle counter, we
+ * don't have any idea of its true resolution
+ * exported, but it is much more than 1s/HZ.
+ */
+ tp->tv_nsec = 1;
+ }
+ }
+ return error;
+}
+
+static int
+posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp)
+{
+ /*
+ * You can never reset a CPU clock, but we check for other errors
+ * in the call before failing with EPERM.
+ */
+ int error = check_clock(which_clock);
+ if (error == 0) {
+ error = -EPERM;
+ }
+ return error;
+}
+
+
+/*
+ * Sample a per-thread clock for the given task.
+ */
+static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p,
+ unsigned long long *sample)
+{
+ switch (CPUCLOCK_WHICH(which_clock)) {
+ default:
+ return -EINVAL;
+ case CPUCLOCK_PROF:
+ *sample = prof_ticks(p);
+ break;
+ case CPUCLOCK_VIRT:
+ *sample = virt_ticks(p);
+ break;
+ case CPUCLOCK_SCHED:
+ *sample = task_sched_runtime(p);
+ break;
+ }
+ return 0;
+}
+
+static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b)
+{
+ if (b->utime > a->utime)
+ a->utime = b->utime;
+
+ if (b->stime > a->stime)
+ a->stime = b->stime;
+
+ if (b->sum_exec_runtime > a->sum_exec_runtime)
+ a->sum_exec_runtime = b->sum_exec_runtime;
+}
+
+void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
+{
+ struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
+ struct task_cputime sum;
+ unsigned long flags;
+
+ if (!cputimer->running) {
+ /*
+ * The POSIX timer interface allows for absolute time expiry
+ * values through the TIMER_ABSTIME flag, therefore we have
+ * to synchronize the timer to the clock every time we start
+ * it.
+ */
+ thread_group_cputime(tsk, &sum);
+ raw_spin_lock_irqsave(&cputimer->lock, flags);
+ cputimer->running = 1;
+ update_gt_cputime(&cputimer->cputime, &sum);
+ } else
+ raw_spin_lock_irqsave(&cputimer->lock, flags);
+ *times = cputimer->cputime;
+ raw_spin_unlock_irqrestore(&cputimer->lock, flags);
+}
+
+/*
+ * Sample a process (thread group) clock for the given group_leader task.
+ * Must be called with task sighand lock held for safe while_each_thread()
+ * traversal.
+ */
+static int cpu_clock_sample_group(const clockid_t which_clock,
+ struct task_struct *p,
+ unsigned long long *sample)
+{
+ struct task_cputime cputime;
+
+ switch (CPUCLOCK_WHICH(which_clock)) {
+ default:
+ return -EINVAL;
+ case CPUCLOCK_PROF:
+ thread_group_cputime(p, &cputime);
+ *sample = cputime_to_expires(cputime.utime + cputime.stime);
+ break;
+ case CPUCLOCK_VIRT:
+ thread_group_cputime(p, &cputime);
+ *sample = cputime_to_expires(cputime.utime);
+ break;
+ case CPUCLOCK_SCHED:
+ thread_group_cputime(p, &cputime);
+ *sample = cputime.sum_exec_runtime;
+ break;
+ }
+ return 0;
+}
+
+static int posix_cpu_clock_get_task(struct task_struct *tsk,
+ const clockid_t which_clock,
+ struct timespec *tp)
+{
+ int err = -EINVAL;
+ unsigned long long rtn;
+
+ if (CPUCLOCK_PERTHREAD(which_clock)) {
+ if (same_thread_group(tsk, current))
+ err = cpu_clock_sample(which_clock, tsk, &rtn);
+ } else {
+ if (tsk == current || thread_group_leader(tsk))
+ err = cpu_clock_sample_group(which_clock, tsk, &rtn);
+ }
+
+ if (!err)
+ sample_to_timespec(which_clock, rtn, tp);
+
+ return err;
+}
+
+
+static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
+{
+ const pid_t pid = CPUCLOCK_PID(which_clock);
+ int err = -EINVAL;
+
+ if (pid == 0) {
+ /*
+ * Special case constant value for our own clocks.
+ * We don't have to do any lookup to find ourselves.
+ */
+ err = posix_cpu_clock_get_task(current, which_clock, tp);
+ } else {
+ /*
+ * Find the given PID, and validate that the caller
+ * should be able to see it.
+ */
+ struct task_struct *p;
+ rcu_read_lock();
+ p = find_task_by_vpid(pid);
+ if (p)
+ err = posix_cpu_clock_get_task(p, which_clock, tp);
+ rcu_read_unlock();
+ }
+
+ return err;
+}
+
+
+/*
+ * Validate the clockid_t for a new CPU-clock timer, and initialize the timer.
+ * This is called from sys_timer_create() and do_cpu_nanosleep() with the
+ * new timer already all-zeros initialized.
+ */
+static int posix_cpu_timer_create(struct k_itimer *new_timer)
+{
+ int ret = 0;
+ const pid_t pid = CPUCLOCK_PID(new_timer->it_clock);
+ struct task_struct *p;
+
+ if (CPUCLOCK_WHICH(new_timer->it_clock) >= CPUCLOCK_MAX)
+ return -EINVAL;
+
+ INIT_LIST_HEAD(&new_timer->it.cpu.entry);
+
+ rcu_read_lock();
+ if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) {
+ if (pid == 0) {
+ p = current;
+ } else {
+ p = find_task_by_vpid(pid);
+ if (p && !same_thread_group(p, current))
+ p = NULL;
+ }
+ } else {
+ if (pid == 0) {
+ p = current->group_leader;
+ } else {
+ p = find_task_by_vpid(pid);
+ if (p && !has_group_leader_pid(p))
+ p = NULL;
+ }
+ }
+ new_timer->it.cpu.task = p;
+ if (p) {
+ get_task_struct(p);
+ } else {
+ ret = -EINVAL;
+ }
+ rcu_read_unlock();
+
+ return ret;
+}
+
+/*
+ * Clean up a CPU-clock timer that is about to be destroyed.
+ * This is called from timer deletion with the timer already locked.
+ * If we return TIMER_RETRY, it's necessary to release the timer's lock
+ * and try again. (This happens when the timer is in the middle of firing.)
+ */
+static int posix_cpu_timer_del(struct k_itimer *timer)
+{
+ int ret = 0;
+ unsigned long flags;
+ struct sighand_struct *sighand;
+ struct task_struct *p = timer->it.cpu.task;
+
+ WARN_ON_ONCE(p == NULL);
+
+ /*
+ * Protect against sighand release/switch in exit/exec and process/
+ * thread timer list entry concurrent read/writes.
+ */
+ sighand = lock_task_sighand(p, &flags);
+ if (unlikely(sighand == NULL)) {
+ /*
+ * We raced with the reaping of the task.
+ * The deletion should have cleared us off the list.
+ */
+ WARN_ON_ONCE(!list_empty(&timer->it.cpu.entry));
+ } else {
+ if (timer->it.cpu.firing)
+ ret = TIMER_RETRY;
+ else
+ list_del(&timer->it.cpu.entry);
+
+ unlock_task_sighand(p, &flags);
+ }
+
+ if (!ret)
+ put_task_struct(p);
+
+ return ret;
+}
+
+static void cleanup_timers_list(struct list_head *head)
+{
+ struct cpu_timer_list *timer, *next;
+
+ list_for_each_entry_safe(timer, next, head, entry)
+ list_del_init(&timer->entry);
+}
+
+/*
+ * Clean out CPU timers still ticking when a thread exited. The task
+ * pointer is cleared, and the expiry time is replaced with the residual
+ * time for later timer_gettime calls to return.
+ * This must be called with the siglock held.
+ */
+static void cleanup_timers(struct list_head *head)
+{
+ cleanup_timers_list(head);
+ cleanup_timers_list(++head);
+ cleanup_timers_list(++head);
+}
+
+/*
+ * These are both called with the siglock held, when the current thread
+ * is being reaped. When the final (leader) thread in the group is reaped,
+ * posix_cpu_timers_exit_group will be called after posix_cpu_timers_exit.
+ */
+void posix_cpu_timers_exit(struct task_struct *tsk)
+{
+ add_device_randomness((const void*) &tsk->se.sum_exec_runtime,
+ sizeof(unsigned long long));
+ cleanup_timers(tsk->cpu_timers);
+
+}
+void posix_cpu_timers_exit_group(struct task_struct *tsk)
+{
+ cleanup_timers(tsk->signal->cpu_timers);
+}
+
+static inline int expires_gt(cputime_t expires, cputime_t new_exp)
+{
+ return expires == 0 || expires > new_exp;
+}
+
+/*
+ * Insert the timer on the appropriate list before any timers that
+ * expire later. This must be called with the sighand lock held.
+ */
+static void arm_timer(struct k_itimer *timer)
+{
+ struct task_struct *p = timer->it.cpu.task;
+ struct list_head *head, *listpos;
+ struct task_cputime *cputime_expires;
+ struct cpu_timer_list *const nt = &timer->it.cpu;
+ struct cpu_timer_list *next;
+
+ if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
+ head = p->cpu_timers;
+ cputime_expires = &p->cputime_expires;
+ } else {
+ head = p->signal->cpu_timers;
+ cputime_expires = &p->signal->cputime_expires;
+ }
+ head += CPUCLOCK_WHICH(timer->it_clock);
+
+ listpos = head;
+ list_for_each_entry(next, head, entry) {
+ if (nt->expires < next->expires)
+ break;
+ listpos = &next->entry;
+ }
+ list_add(&nt->entry, listpos);
+
+ if (listpos == head) {
+ unsigned long long exp = nt->expires;
+
+ /*
+ * We are the new earliest-expiring POSIX 1.b timer, hence
+ * need to update expiration cache. Take into account that
+ * for process timers we share expiration cache with itimers
+ * and RLIMIT_CPU and for thread timers with RLIMIT_RTTIME.
+ */
+
+ switch (CPUCLOCK_WHICH(timer->it_clock)) {
+ case CPUCLOCK_PROF:
+ if (expires_gt(cputime_expires->prof_exp, expires_to_cputime(exp)))
+ cputime_expires->prof_exp = expires_to_cputime(exp);
+ break;
+ case CPUCLOCK_VIRT:
+ if (expires_gt(cputime_expires->virt_exp, expires_to_cputime(exp)))
+ cputime_expires->virt_exp = expires_to_cputime(exp);
+ break;
+ case CPUCLOCK_SCHED:
+ if (cputime_expires->sched_exp == 0 ||
+ cputime_expires->sched_exp > exp)
+ cputime_expires->sched_exp = exp;
+ break;
+ }
+ }
+}
+
+/*
+ * The timer is locked, fire it and arrange for its reload.
+ */
+static void cpu_timer_fire(struct k_itimer *timer)
+{
+ if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
+ /*
+ * User don't want any signal.
+ */
+ timer->it.cpu.expires = 0;
+ } else if (unlikely(timer->sigq == NULL)) {
+ /*
+ * This a special case for clock_nanosleep,
+ * not a normal timer from sys_timer_create.
+ */
+ wake_up_process(timer->it_process);
+ timer->it.cpu.expires = 0;
+ } else if (timer->it.cpu.incr == 0) {
+ /*
+ * One-shot timer. Clear it as soon as it's fired.
+ */
+ posix_timer_event(timer, 0);
+ timer->it.cpu.expires = 0;
+ } else if (posix_timer_event(timer, ++timer->it_requeue_pending)) {
+ /*
+ * The signal did not get queued because the signal
+ * was ignored, so we won't get any callback to
+ * reload the timer. But we need to keep it
+ * ticking in case the signal is deliverable next time.
+ */
+ posix_cpu_timer_schedule(timer);
+ }
+}
+
+/*
+ * Sample a process (thread group) timer for the given group_leader task.
+ * Must be called with task sighand lock held for safe while_each_thread()
+ * traversal.
+ */
+static int cpu_timer_sample_group(const clockid_t which_clock,
+ struct task_struct *p,
+ unsigned long long *sample)
+{
+ struct task_cputime cputime;
+
+ thread_group_cputimer(p, &cputime);
+ switch (CPUCLOCK_WHICH(which_clock)) {
+ default:
+ return -EINVAL;
+ case CPUCLOCK_PROF:
+ *sample = cputime_to_expires(cputime.utime + cputime.stime);
+ break;
+ case CPUCLOCK_VIRT:
+ *sample = cputime_to_expires(cputime.utime);
+ break;
+ case CPUCLOCK_SCHED:
+ *sample = cputime.sum_exec_runtime;
+ break;
+ }
+ return 0;
+}
+
+#ifdef CONFIG_NO_HZ_FULL
+static void nohz_kick_work_fn(struct work_struct *work)
+{
+ tick_nohz_full_kick_all();
+}
+
+static DECLARE_WORK(nohz_kick_work, nohz_kick_work_fn);
+
+/*
+ * We need the IPIs to be sent from sane process context.
+ * The posix cpu timers are always set with irqs disabled.
+ */
+static void posix_cpu_timer_kick_nohz(void)
+{
+ if (context_tracking_is_enabled())
+ schedule_work(&nohz_kick_work);
+}
+
+bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk)
+{
+ if (!task_cputime_zero(&tsk->cputime_expires))
+ return false;
+
+ if (tsk->signal->cputimer.running)
+ return false;
+
+ return true;
+}
+#else
+static inline void posix_cpu_timer_kick_nohz(void) { }
+#endif
+
+/*
+ * Guts of sys_timer_settime for CPU timers.
+ * This is called with the timer locked and interrupts disabled.
+ * If we return TIMER_RETRY, it's necessary to release the timer's lock
+ * and try again. (This happens when the timer is in the middle of firing.)
+ */
+static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
+ struct itimerspec *new, struct itimerspec *old)
+{
+ unsigned long flags;
+ struct sighand_struct *sighand;
+ struct task_struct *p = timer->it.cpu.task;
+ unsigned long long old_expires, new_expires, old_incr, val;
+ int ret;
+
+ WARN_ON_ONCE(p == NULL);
+
+ new_expires = timespec_to_sample(timer->it_clock, &new->it_value);
+
+ /*
+ * Protect against sighand release/switch in exit/exec and p->cpu_timers
+ * and p->signal->cpu_timers read/write in arm_timer()
+ */
+ sighand = lock_task_sighand(p, &flags);
+ /*
+ * If p has just been reaped, we can no
+ * longer get any information about it at all.
+ */
+ if (unlikely(sighand == NULL)) {
+ return -ESRCH;
+ }
+
+ /*
+ * Disarm any old timer after extracting its expiry time.
+ */
+ WARN_ON_ONCE_NONRT(!irqs_disabled());
+
+ ret = 0;
+ old_incr = timer->it.cpu.incr;
+ old_expires = timer->it.cpu.expires;
+ if (unlikely(timer->it.cpu.firing)) {
+ timer->it.cpu.firing = -1;
+ ret = TIMER_RETRY;
+ } else
+ list_del_init(&timer->it.cpu.entry);
+
+ /*
+ * We need to sample the current value to convert the new
+ * value from to relative and absolute, and to convert the
+ * old value from absolute to relative. To set a process
+ * timer, we need a sample to balance the thread expiry
+ * times (in arm_timer). With an absolute time, we must
+ * check if it's already passed. In short, we need a sample.
+ */
+ if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
+ cpu_clock_sample(timer->it_clock, p, &val);
+ } else {
+ cpu_timer_sample_group(timer->it_clock, p, &val);
+ }
+
+ if (old) {
+ if (old_expires == 0) {
+ old->it_value.tv_sec = 0;
+ old->it_value.tv_nsec = 0;
+ } else {
+ /*
+ * Update the timer in case it has
+ * overrun already. If it has,
+ * we'll report it as having overrun
+ * and with the next reloaded timer
+ * already ticking, though we are
+ * swallowing that pending
+ * notification here to install the
+ * new setting.
+ */
+ bump_cpu_timer(timer, val);
+ if (val < timer->it.cpu.expires) {
+ old_expires = timer->it.cpu.expires - val;
+ sample_to_timespec(timer->it_clock,
+ old_expires,
+ &old->it_value);
+ } else {
+ old->it_value.tv_nsec = 1;
+ old->it_value.tv_sec = 0;
+ }
+ }
+ }
+
+ if (unlikely(ret)) {
+ /*
+ * We are colliding with the timer actually firing.
+ * Punt after filling in the timer's old value, and
+ * disable this firing since we are already reporting
+ * it as an overrun (thanks to bump_cpu_timer above).
+ */
+ unlock_task_sighand(p, &flags);
+ goto out;
+ }
+
+ if (new_expires != 0 && !(timer_flags & TIMER_ABSTIME)) {
+ new_expires += val;
+ }
+
+ /*
+ * Install the new expiry time (or zero).
+ * For a timer with no notification action, we don't actually
+ * arm the timer (we'll just fake it for timer_gettime).
+ */
+ timer->it.cpu.expires = new_expires;
+ if (new_expires != 0 && val < new_expires) {
+ arm_timer(timer);
+ }
+
+ unlock_task_sighand(p, &flags);
+ /*
+ * Install the new reload setting, and
+ * set up the signal and overrun bookkeeping.
+ */
+ timer->it.cpu.incr = timespec_to_sample(timer->it_clock,
+ &new->it_interval);
+
+ /*
+ * This acts as a modification timestamp for the timer,
+ * so any automatic reload attempt will punt on seeing
+ * that we have reset the timer manually.
+ */
+ timer->it_requeue_pending = (timer->it_requeue_pending + 2) &
+ ~REQUEUE_PENDING;
+ timer->it_overrun_last = 0;
+ timer->it_overrun = -1;
+
+ if (new_expires != 0 && !(val < new_expires)) {
+ /*
+ * The designated time already passed, so we notify
+ * immediately, even if the thread never runs to
+ * accumulate more time on this clock.
+ */
+ cpu_timer_fire(timer);
+ }
+
+ ret = 0;
+ out:
+ if (old) {
+ sample_to_timespec(timer->it_clock,
+ old_incr, &old->it_interval);
+ }
+ if (!ret)
+ posix_cpu_timer_kick_nohz();
+ return ret;
+}
+
+static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
+{
+ unsigned long long now;
+ struct task_struct *p = timer->it.cpu.task;
+
+ WARN_ON_ONCE(p == NULL);
+
+ /*
+ * Easy part: convert the reload time.
+ */
+ sample_to_timespec(timer->it_clock,
+ timer->it.cpu.incr, &itp->it_interval);
+
+ if (timer->it.cpu.expires == 0) { /* Timer not armed at all. */
+ itp->it_value.tv_sec = itp->it_value.tv_nsec = 0;
+ return;
+ }
+
+ /*
+ * Sample the clock to take the difference with the expiry time.
+ */
+ if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
+ cpu_clock_sample(timer->it_clock, p, &now);
+ } else {
+ struct sighand_struct *sighand;
+ unsigned long flags;
+
+ /*
+ * Protect against sighand release/switch in exit/exec and
+ * also make timer sampling safe if it ends up calling
+ * thread_group_cputime().
+ */
+ sighand = lock_task_sighand(p, &flags);
+ if (unlikely(sighand == NULL)) {
+ /*
+ * The process has been reaped.
+ * We can't even collect a sample any more.
+ * Call the timer disarmed, nothing else to do.
+ */
+ timer->it.cpu.expires = 0;
+ sample_to_timespec(timer->it_clock, timer->it.cpu.expires,
+ &itp->it_value);
+ } else {
+ cpu_timer_sample_group(timer->it_clock, p, &now);
+ unlock_task_sighand(p, &flags);
+ }
+ }
+
+ if (now < timer->it.cpu.expires) {
+ sample_to_timespec(timer->it_clock,
+ timer->it.cpu.expires - now,
+ &itp->it_value);
+ } else {
+ /*
+ * The timer should have expired already, but the firing
+ * hasn't taken place yet. Say it's just about to expire.
+ */
+ itp->it_value.tv_nsec = 1;
+ itp->it_value.tv_sec = 0;
+ }
+}
+
+static unsigned long long
+check_timers_list(struct list_head *timers,
+ struct list_head *firing,
+ unsigned long long curr)
+{
+ int maxfire = 20;
+
+ while (!list_empty(timers)) {
+ struct cpu_timer_list *t;
+
+ t = list_first_entry(timers, struct cpu_timer_list, entry);
+
+ if (!--maxfire || curr < t->expires)
+ return t->expires;
+
+ t->firing = 1;
+ list_move_tail(&t->entry, firing);
+ }
+
+ return 0;
+}
+
+/*
+ * Check for any per-thread CPU timers that have fired and move them off
+ * the tsk->cpu_timers[N] list onto the firing list. Here we update the
+ * tsk->it_*_expires values to reflect the remaining thread CPU timers.
+ */
+static void check_thread_timers(struct task_struct *tsk,
+ struct list_head *firing)
+{
+ struct list_head *timers = tsk->cpu_timers;
+ struct signal_struct *const sig = tsk->signal;
+ struct task_cputime *tsk_expires = &tsk->cputime_expires;
+ unsigned long long expires;
+ unsigned long soft;
+
+ expires = check_timers_list(timers, firing, prof_ticks(tsk));
+ tsk_expires->prof_exp = expires_to_cputime(expires);
+
+ expires = check_timers_list(++timers, firing, virt_ticks(tsk));
+ tsk_expires->virt_exp = expires_to_cputime(expires);
+
+ tsk_expires->sched_exp = check_timers_list(++timers, firing,
+ tsk->se.sum_exec_runtime);
+
+ /*
+ * Check for the special case thread timers.
+ */
+ soft = ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_cur);
+ if (soft != RLIM_INFINITY) {
+ unsigned long hard =
+ ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_max);
+
+ if (hard != RLIM_INFINITY &&
+ tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) {
+ /*
+ * At the hard limit, we just die.
+ * No need to calculate anything else now.
+ */
+ __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
+ return;
+ }
+ if (tsk->rt.timeout > DIV_ROUND_UP(soft, USEC_PER_SEC/HZ)) {
+ /*
+ * At the soft limit, send a SIGXCPU every second.
+ */
+ if (soft < hard) {
+ soft += USEC_PER_SEC;
+ sig->rlim[RLIMIT_RTTIME].rlim_cur = soft;
+ }
+ printk(KERN_INFO
+ "RT Watchdog Timeout: %s[%d]\n",
+ tsk->comm, task_pid_nr(tsk));
+ __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
+ }
+ }
+}
+
+static void stop_process_timers(struct signal_struct *sig)
+{
+ struct thread_group_cputimer *cputimer = &sig->cputimer;
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&cputimer->lock, flags);
+ cputimer->running = 0;
+ raw_spin_unlock_irqrestore(&cputimer->lock, flags);
+}
+
+static u32 onecputick;
+
+static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
+ unsigned long long *expires,
+ unsigned long long cur_time, int signo)
+{
+ if (!it->expires)
+ return;
+
+ if (cur_time >= it->expires) {
+ if (it->incr) {
+ it->expires += it->incr;
+ it->error += it->incr_error;
+ if (it->error >= onecputick) {
+ it->expires -= cputime_one_jiffy;
+ it->error -= onecputick;
+ }
+ } else {
+ it->expires = 0;
+ }
+
+ trace_itimer_expire(signo == SIGPROF ?
+ ITIMER_PROF : ITIMER_VIRTUAL,
+ tsk->signal->leader_pid, cur_time);
+ __group_send_sig_info(signo, SEND_SIG_PRIV, tsk);
+ }
+
+ if (it->expires && (!*expires || it->expires < *expires)) {
+ *expires = it->expires;
+ }
+}
+
+/*
+ * Check for any per-thread CPU timers that have fired and move them
+ * off the tsk->*_timers list onto the firing list. Per-thread timers
+ * have already been taken off.
+ */
+static void check_process_timers(struct task_struct *tsk,
+ struct list_head *firing)
+{
+ struct signal_struct *const sig = tsk->signal;
+ unsigned long long utime, ptime, virt_expires, prof_expires;
+ unsigned long long sum_sched_runtime, sched_expires;
+ struct list_head *timers = sig->cpu_timers;
+ struct task_cputime cputime;
+ unsigned long soft;
+
+ /*
+ * Collect the current process totals.
+ */
+ thread_group_cputimer(tsk, &cputime);
+ utime = cputime_to_expires(cputime.utime);
+ ptime = utime + cputime_to_expires(cputime.stime);
+ sum_sched_runtime = cputime.sum_exec_runtime;
+
+ prof_expires = check_timers_list(timers, firing, ptime);
+ virt_expires = check_timers_list(++timers, firing, utime);
+ sched_expires = check_timers_list(++timers, firing, sum_sched_runtime);
+
+ /*
+ * Check for the special case process timers.
+ */
+ check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime,
+ SIGPROF);
+ check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
+ SIGVTALRM);
+ soft = ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
+ if (soft != RLIM_INFINITY) {
+ unsigned long psecs = cputime_to_secs(ptime);
+ unsigned long hard =
+ ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_max);
+ cputime_t x;
+ if (psecs >= hard) {
+ /*
+ * At the hard limit, we just die.
+ * No need to calculate anything else now.
+ */
+ __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
+ return;
+ }
+ if (psecs >= soft) {
+ /*
+ * At the soft limit, send a SIGXCPU every second.
+ */
+ __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
+ if (soft < hard) {
+ soft++;
+ sig->rlim[RLIMIT_CPU].rlim_cur = soft;
+ }
+ }
+ x = secs_to_cputime(soft);
+ if (!prof_expires || x < prof_expires) {
+ prof_expires = x;
+ }
+ }
+
+ sig->cputime_expires.prof_exp = expires_to_cputime(prof_expires);
+ sig->cputime_expires.virt_exp = expires_to_cputime(virt_expires);
+ sig->cputime_expires.sched_exp = sched_expires;
+ if (task_cputime_zero(&sig->cputime_expires))
+ stop_process_timers(sig);
+}
+
+/*
+ * This is called from the signal code (via do_schedule_next_timer)
+ * when the last timer signal was delivered and we have to reload the timer.
+ */
+void posix_cpu_timer_schedule(struct k_itimer *timer)
+{
+ struct sighand_struct *sighand;
+ unsigned long flags;
+ struct task_struct *p = timer->it.cpu.task;
+ unsigned long long now;
+
+ WARN_ON_ONCE(p == NULL);
+
+ /*
+ * Fetch the current sample and update the timer's expiry time.
+ */
+ if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
+ cpu_clock_sample(timer->it_clock, p, &now);
+ bump_cpu_timer(timer, now);
+ if (unlikely(p->exit_state))
+ goto out;
+
+ /* Protect timer list r/w in arm_timer() */
+ sighand = lock_task_sighand(p, &flags);
+ if (!sighand)
+ goto out;
+ } else {
+ /*
+ * Protect arm_timer() and timer sampling in case of call to
+ * thread_group_cputime().
+ */
+ sighand = lock_task_sighand(p, &flags);
+ if (unlikely(sighand == NULL)) {
+ /*
+ * The process has been reaped.
+ * We can't even collect a sample any more.
+ */
+ timer->it.cpu.expires = 0;
+ goto out;
+ } else if (unlikely(p->exit_state) && thread_group_empty(p)) {
+ unlock_task_sighand(p, &flags);
+ /* Optimizations: if the process is dying, no need to rearm */
+ goto out;
+ }
+ cpu_timer_sample_group(timer->it_clock, p, &now);
+ bump_cpu_timer(timer, now);
+ /* Leave the sighand locked for the call below. */
+ }
+
+ /*
+ * Now re-arm for the new expiry time.
+ */
+ WARN_ON_ONCE_NONRT(!irqs_disabled());
+ arm_timer(timer);
+ unlock_task_sighand(p, &flags);
+
+ /* Kick full dynticks CPUs in case they need to tick on the new timer */
+ posix_cpu_timer_kick_nohz();
+out:
+ timer->it_overrun_last = timer->it_overrun;
+ timer->it_overrun = -1;
+ ++timer->it_requeue_pending;
+}
+
+/**
+ * task_cputime_expired - Compare two task_cputime entities.
+ *
+ * @sample: The task_cputime structure to be checked for expiration.
+ * @expires: Expiration times, against which @sample will be checked.
+ *
+ * Checks @sample against @expires to see if any field of @sample has expired.
+ * Returns true if any field of the former is greater than the corresponding
+ * field of the latter if the latter field is set. Otherwise returns false.
+ */
+static inline int task_cputime_expired(const struct task_cputime *sample,
+ const struct task_cputime *expires)
+{
+ if (expires->utime && sample->utime >= expires->utime)
+ return 1;
+ if (expires->stime && sample->utime + sample->stime >= expires->stime)
+ return 1;
+ if (expires->sum_exec_runtime != 0 &&
+ sample->sum_exec_runtime >= expires->sum_exec_runtime)
+ return 1;
+ return 0;
+}
+
+/**
+ * fastpath_timer_check - POSIX CPU timers fast path.
+ *
+ * @tsk: The task (thread) being checked.
+ *
+ * Check the task and thread group timers. If both are zero (there are no
+ * timers set) return false. Otherwise snapshot the task and thread group
+ * timers and compare them with the corresponding expiration times. Return
+ * true if a timer has expired, else return false.
+ */
+static inline int fastpath_timer_check(struct task_struct *tsk)
+{
+ struct signal_struct *sig;
+ cputime_t utime, stime;
+
+ task_cputime(tsk, &utime, &stime);
+
+ if (!task_cputime_zero(&tsk->cputime_expires)) {
+ struct task_cputime task_sample = {
+ .utime = utime,
+ .stime = stime,
+ .sum_exec_runtime = tsk->se.sum_exec_runtime
+ };
+
+ if (task_cputime_expired(&task_sample, &tsk->cputime_expires))
+ return 1;
+ }
+
+ sig = tsk->signal;
+ if (sig->cputimer.running) {
+ struct task_cputime group_sample;
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&sig->cputimer.lock, flags);
+ group_sample = sig->cputimer.cputime;
+ raw_spin_unlock_irqrestore(&sig->cputimer.lock, flags);
+
+ if (task_cputime_expired(&group_sample, &sig->cputime_expires))
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ * This is called from the timer interrupt handler. The irq handler has
+ * already updated our counts. We need to check if any timers fire now.
+ * Interrupts are disabled.
+ */
+static void __run_posix_cpu_timers(struct task_struct *tsk)
+{
+ LIST_HEAD(firing);
+ struct k_itimer *timer, *next;
+ unsigned long flags;
+
+ WARN_ON_ONCE_NONRT(!irqs_disabled());
+
+ /*
+ * The fast path checks that there are no expired thread or thread
+ * group timers. If that's so, just return.
+ */
+ if (!fastpath_timer_check(tsk))
+ return;
+
+ if (!lock_task_sighand(tsk, &flags))
+ return;
+ /*
+ * Here we take off tsk->signal->cpu_timers[N] and
+ * tsk->cpu_timers[N] all the timers that are firing, and
+ * put them on the firing list.
+ */
+ check_thread_timers(tsk, &firing);
+ /*
+ * If there are any active process wide timers (POSIX 1.b, itimers,
+ * RLIMIT_CPU) cputimer must be running.
+ */
+ if (tsk->signal->cputimer.running)
+ check_process_timers(tsk, &firing);
+
+ /*
+ * We must release these locks before taking any timer's lock.
+ * There is a potential race with timer deletion here, as the
+ * siglock now protects our private firing list. We have set
+ * the firing flag in each timer, so that a deletion attempt
+ * that gets the timer lock before we do will give it up and
+ * spin until we've taken care of that timer below.
+ */
+ unlock_task_sighand(tsk, &flags);
+
+ /*
+ * Now that all the timers on our list have the firing flag,
+ * no one will touch their list entries but us. We'll take
+ * each timer's lock before clearing its firing flag, so no
+ * timer call will interfere.
+ */
+ list_for_each_entry_safe(timer, next, &firing, it.cpu.entry) {
+ int cpu_firing;
+
+ spin_lock(&timer->it_lock);
+ list_del_init(&timer->it.cpu.entry);
+ cpu_firing = timer->it.cpu.firing;
+ timer->it.cpu.firing = 0;
+ /*
+ * The firing flag is -1 if we collided with a reset
+ * of the timer, which already reported this
+ * almost-firing as an overrun. So don't generate an event.
+ */
+ if (likely(cpu_firing >= 0))
+ cpu_timer_fire(timer);
+ spin_unlock(&timer->it_lock);
+ }
+}
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+#include <linux/kthread.h>
+#include <linux/cpu.h>
+DEFINE_PER_CPU(struct task_struct *, posix_timer_task);
+DEFINE_PER_CPU(struct task_struct *, posix_timer_tasklist);
+
+static int posix_cpu_timers_thread(void *data)
+{
+ int cpu = (long)data;
+
+ BUG_ON(per_cpu(posix_timer_task,cpu) != current);
+
+ while (!kthread_should_stop()) {
+ struct task_struct *tsk = NULL;
+ struct task_struct *next = NULL;
+
+ if (cpu_is_offline(cpu))
+ goto wait_to_die;
+
+ /* grab task list */
+ raw_local_irq_disable();
+ tsk = per_cpu(posix_timer_tasklist, cpu);
+ per_cpu(posix_timer_tasklist, cpu) = NULL;
+ raw_local_irq_enable();
+
+ /* its possible the list is empty, just return */
+ if (!tsk) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule();
+ __set_current_state(TASK_RUNNING);
+ continue;
+ }
+
+ /* Process task list */
+ while (1) {
+ /* save next */
+ next = tsk->posix_timer_list;
+
+ /* run the task timers, clear its ptr and
+ * unreference it
+ */
+ __run_posix_cpu_timers(tsk);
+ tsk->posix_timer_list = NULL;
+ put_task_struct(tsk);
+
+ /* check if this is the last on the list */
+ if (next == tsk)
+ break;
+ tsk = next;
+ }
+ }
+ return 0;
+
+wait_to_die:
+ /* Wait for kthread_stop */
+ set_current_state(TASK_INTERRUPTIBLE);
+ while (!kthread_should_stop()) {
+ schedule();
+ set_current_state(TASK_INTERRUPTIBLE);
+ }
+ __set_current_state(TASK_RUNNING);
+ return 0;
+}
+
+static inline int __fastpath_timer_check(struct task_struct *tsk)
+{
+ /* tsk == current, ensure it is safe to use ->signal/sighand */
+ if (unlikely(tsk->exit_state))
+ return 0;
+
+ if (!task_cputime_zero(&tsk->cputime_expires))
+ return 1;
+
+ if (!task_cputime_zero(&tsk->signal->cputime_expires))
+ return 1;
+
+ return 0;
+}
+
+void run_posix_cpu_timers(struct task_struct *tsk)
+{
+ unsigned long cpu = smp_processor_id();
+ struct task_struct *tasklist;
+
+ BUG_ON(!irqs_disabled());
+ if(!per_cpu(posix_timer_task, cpu))
+ return;
+ /* get per-cpu references */
+ tasklist = per_cpu(posix_timer_tasklist, cpu);
+
+ /* check to see if we're already queued */
+ if (!tsk->posix_timer_list && __fastpath_timer_check(tsk)) {
+ get_task_struct(tsk);
+ if (tasklist) {
+ tsk->posix_timer_list = tasklist;
+ } else {
+ /*
+ * The list is terminated by a self-pointing
+ * task_struct
+ */
+ tsk->posix_timer_list = tsk;
+ }
+ per_cpu(posix_timer_tasklist, cpu) = tsk;
+
+ wake_up_process(per_cpu(posix_timer_task, cpu));
+ }
+}
+
+/*
+ * posix_cpu_thread_call - callback that gets triggered when a CPU is added.
+ * Here we can start up the necessary migration thread for the new CPU.
+ */
+static int posix_cpu_thread_call(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ int cpu = (long)hcpu;
+ struct task_struct *p;
+ struct sched_param param;
+
+ switch (action) {
+ case CPU_UP_PREPARE:
+ p = kthread_create(posix_cpu_timers_thread, hcpu,
+ "posixcputmr/%d",cpu);
+ if (IS_ERR(p))
+ return NOTIFY_BAD;
+ p->flags |= PF_NOFREEZE;
+ kthread_bind(p, cpu);
+ /* Must be high prio to avoid getting starved */
+ param.sched_priority = MAX_RT_PRIO-1;
+ sched_setscheduler(p, SCHED_FIFO, ¶m);
+ per_cpu(posix_timer_task,cpu) = p;
+ break;
+ case CPU_ONLINE:
+ /* Strictly unneccessary, as first user will wake it. */
+ wake_up_process(per_cpu(posix_timer_task,cpu));
+ break;
+#ifdef CONFIG_HOTPLUG_CPU
+ case CPU_UP_CANCELED:
+ /* Unbind it from offline cpu so it can run. Fall thru. */
+ kthread_bind(per_cpu(posix_timer_task, cpu),
+ cpumask_any(cpu_online_mask));
+ kthread_stop(per_cpu(posix_timer_task,cpu));
+ per_cpu(posix_timer_task,cpu) = NULL;
+ break;
+ case CPU_DEAD:
+ kthread_stop(per_cpu(posix_timer_task,cpu));
+ per_cpu(posix_timer_task,cpu) = NULL;
+ break;
+#endif
+ }
+ return NOTIFY_OK;
+}
+
+/* Register at highest priority so that task migration (migrate_all_tasks)
+ * happens before everything else.
+ */
+static struct notifier_block posix_cpu_thread_notifier = {
+ .notifier_call = posix_cpu_thread_call,
+ .priority = 10
+};
+
+static int __init posix_cpu_thread_init(void)
+{
+ void *hcpu = (void *)(long)smp_processor_id();
+ /* Start one for boot CPU. */
+ unsigned long cpu;
+
+ /* init the per-cpu posix_timer_tasklets */
+ for_each_possible_cpu(cpu)
+ per_cpu(posix_timer_tasklist, cpu) = NULL;
+
+ posix_cpu_thread_call(&posix_cpu_thread_notifier, CPU_UP_PREPARE, hcpu);
+ posix_cpu_thread_call(&posix_cpu_thread_notifier, CPU_ONLINE, hcpu);
+ register_cpu_notifier(&posix_cpu_thread_notifier);
+ return 0;
+}
+early_initcall(posix_cpu_thread_init);
+#else /* CONFIG_PREEMPT_RT_BASE */
+void run_posix_cpu_timers(struct task_struct *tsk)
+{
+ __run_posix_cpu_timers(tsk);
+}
+#endif /* CONFIG_PREEMPT_RT_BASE */
+
+/*
+ * Set one of the process-wide special case CPU timers or RLIMIT_CPU.
+ * The tsk->sighand->siglock must be held by the caller.
+ */
+void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
+ cputime_t *newval, cputime_t *oldval)
+{
+ unsigned long long now;
+
+ WARN_ON_ONCE(clock_idx == CPUCLOCK_SCHED);
+ cpu_timer_sample_group(clock_idx, tsk, &now);
+
+ if (oldval) {
+ /*
+ * We are setting itimer. The *oldval is absolute and we update
+ * it to be relative, *newval argument is relative and we update
+ * it to be absolute.
+ */
+ if (*oldval) {
+ if (*oldval <= now) {
+ /* Just about to fire. */
+ *oldval = cputime_one_jiffy;
+ } else {
+ *oldval -= now;
+ }
+ }
+
+ if (!*newval)
+ goto out;
+ *newval += now;
+ }
+
+ /*
+ * Update expiration cache if we are the earliest timer, or eventually
+ * RLIMIT_CPU limit is earlier than prof_exp cpu timer expire.
+ */
+ switch (clock_idx) {
+ case CPUCLOCK_PROF:
+ if (expires_gt(tsk->signal->cputime_expires.prof_exp, *newval))
+ tsk->signal->cputime_expires.prof_exp = *newval;
+ break;
+ case CPUCLOCK_VIRT:
+ if (expires_gt(tsk->signal->cputime_expires.virt_exp, *newval))
+ tsk->signal->cputime_expires.virt_exp = *newval;
+ break;
+ }
+out:
+ posix_cpu_timer_kick_nohz();
+}
+
+static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
+ struct timespec *rqtp, struct itimerspec *it)
+{
+ struct k_itimer timer;
+ int error;
+
+ /*
+ * Set up a temporary timer and then wait for it to go off.
+ */
+ memset(&timer, 0, sizeof timer);
+ spin_lock_init(&timer.it_lock);
+ timer.it_clock = which_clock;
+ timer.it_overrun = -1;
+ error = posix_cpu_timer_create(&timer);
+ timer.it_process = current;
+ if (!error) {
+ static struct itimerspec zero_it;
+
+ memset(it, 0, sizeof *it);
+ it->it_value = *rqtp;
+
+ spin_lock_irq(&timer.it_lock);
+ error = posix_cpu_timer_set(&timer, flags, it, NULL);
+ if (error) {
+ spin_unlock_irq(&timer.it_lock);
+ return error;
+ }
+
+ while (!signal_pending(current)) {
+ if (timer.it.cpu.expires == 0) {
+ /*
+ * Our timer fired and was reset, below
+ * deletion can not fail.
+ */
+ posix_cpu_timer_del(&timer);
+ spin_unlock_irq(&timer.it_lock);
+ return 0;
+ }
+
+ /*
+ * Block until cpu_timer_fire (or a signal) wakes us.
+ */
+ __set_current_state(TASK_INTERRUPTIBLE);
+ spin_unlock_irq(&timer.it_lock);
+ schedule();
+ spin_lock_irq(&timer.it_lock);
+ }
+
+ /*
+ * We were interrupted by a signal.
+ */
+ sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp);
+ error = posix_cpu_timer_set(&timer, 0, &zero_it, it);
+ if (!error) {
+ /*
+ * Timer is now unarmed, deletion can not fail.
+ */
+ posix_cpu_timer_del(&timer);
+ }
+ spin_unlock_irq(&timer.it_lock);
+
+ while (error == TIMER_RETRY) {
+ /*
+ * We need to handle case when timer was or is in the
+ * middle of firing. In other cases we already freed
+ * resources.
+ */
+ spin_lock_irq(&timer.it_lock);
+ error = posix_cpu_timer_del(&timer);
+ spin_unlock_irq(&timer.it_lock);
+ }
+
+ if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) {
+ /*
+ * It actually did fire already.
+ */
+ return 0;
+ }
+
+ error = -ERESTART_RESTARTBLOCK;
+ }
+
+ return error;
+}
+
+static long posix_cpu_nsleep_restart(struct restart_block *restart_block);
+
+static int posix_cpu_nsleep(const clockid_t which_clock, int flags,
+ struct timespec *rqtp, struct timespec __user *rmtp)
+{
+ struct restart_block *restart_block = ¤t->restart_block;
+ struct itimerspec it;
+ int error;
+
+ /*
+ * Diagnose required errors first.
+ */
+ if (CPUCLOCK_PERTHREAD(which_clock) &&
+ (CPUCLOCK_PID(which_clock) == 0 ||
+ CPUCLOCK_PID(which_clock) == current->pid))
+ return -EINVAL;
+
+ error = do_cpu_nanosleep(which_clock, flags, rqtp, &it);
+
+ if (error == -ERESTART_RESTARTBLOCK) {
+
+ if (flags & TIMER_ABSTIME)
+ return -ERESTARTNOHAND;
+ /*
+ * Report back to the user the time still remaining.
+ */
+ if (rmtp && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
+ return -EFAULT;
+
+ restart_block->fn = posix_cpu_nsleep_restart;
+ restart_block->nanosleep.clockid = which_clock;
+ restart_block->nanosleep.rmtp = rmtp;
+ restart_block->nanosleep.expires = timespec_to_ns(rqtp);
+ }
+ return error;
+}
+
+static long posix_cpu_nsleep_restart(struct restart_block *restart_block)
+{
+ clockid_t which_clock = restart_block->nanosleep.clockid;
+ struct timespec t;
+ struct itimerspec it;
+ int error;
+
+ t = ns_to_timespec(restart_block->nanosleep.expires);
+
+ error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it);
+
+ if (error == -ERESTART_RESTARTBLOCK) {
+ struct timespec __user *rmtp = restart_block->nanosleep.rmtp;
+ /*
+ * Report back to the user the time still remaining.
+ */
+ if (rmtp && copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
+ return -EFAULT;
+
+ restart_block->nanosleep.expires = timespec_to_ns(&t);
+ }
+ return error;
+
+}
+
+#define PROCESS_CLOCK MAKE_PROCESS_CPUCLOCK(0, CPUCLOCK_SCHED)
+#define THREAD_CLOCK MAKE_THREAD_CPUCLOCK(0, CPUCLOCK_SCHED)
+
+static int process_cpu_clock_getres(const clockid_t which_clock,
+ struct timespec *tp)
+{
+ return posix_cpu_clock_getres(PROCESS_CLOCK, tp);
+}
+static int process_cpu_clock_get(const clockid_t which_clock,
+ struct timespec *tp)
+{
+ return posix_cpu_clock_get(PROCESS_CLOCK, tp);
+}
+static int process_cpu_timer_create(struct k_itimer *timer)
+{
+ timer->it_clock = PROCESS_CLOCK;
+ return posix_cpu_timer_create(timer);
+}
+static int process_cpu_nsleep(const clockid_t which_clock, int flags,
+ struct timespec *rqtp,
+ struct timespec __user *rmtp)
+{
+ return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp, rmtp);
+}
+static long process_cpu_nsleep_restart(struct restart_block *restart_block)
+{
+ return -EINVAL;
+}
+static int thread_cpu_clock_getres(const clockid_t which_clock,
+ struct timespec *tp)
+{
+ return posix_cpu_clock_getres(THREAD_CLOCK, tp);
+}
+static int thread_cpu_clock_get(const clockid_t which_clock,
+ struct timespec *tp)
+{
+ return posix_cpu_clock_get(THREAD_CLOCK, tp);
+}
+static int thread_cpu_timer_create(struct k_itimer *timer)
+{
+ timer->it_clock = THREAD_CLOCK;
+ return posix_cpu_timer_create(timer);
+}
+
+struct k_clock clock_posix_cpu = {
+ .clock_getres = posix_cpu_clock_getres,
+ .clock_set = posix_cpu_clock_set,
+ .clock_get = posix_cpu_clock_get,
+ .timer_create = posix_cpu_timer_create,
+ .nsleep = posix_cpu_nsleep,
+ .nsleep_restart = posix_cpu_nsleep_restart,
+ .timer_set = posix_cpu_timer_set,
+ .timer_del = posix_cpu_timer_del,
+ .timer_get = posix_cpu_timer_get,
+};
+
+static __init int init_posix_cpu_timers(void)
+{
+ struct k_clock process = {
+ .clock_getres = process_cpu_clock_getres,
+ .clock_get = process_cpu_clock_get,
+ .timer_create = process_cpu_timer_create,
+ .nsleep = process_cpu_nsleep,
+ .nsleep_restart = process_cpu_nsleep_restart,
+ };
+ struct k_clock thread = {
+ .clock_getres = thread_cpu_clock_getres,
+ .clock_get = thread_cpu_clock_get,
+ .timer_create = thread_cpu_timer_create,
+ };
+ struct timespec ts;
+
+ posix_timers_register_clock(CLOCK_PROCESS_CPUTIME_ID, &process);
+ posix_timers_register_clock(CLOCK_THREAD_CPUTIME_ID, &thread);
+
+ cputime_to_timespec(cputime_one_jiffy, &ts);
+ onecputick = ts.tv_nsec;
+ WARN_ON(ts.tv_sec != 0);
+
+ return 0;
+}
+__initcall(init_posix_cpu_timers);
Code Review / kvmfornfv.git / blobdiff