Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
new file mode 100644
index 0000000..ad85d3f
--- /dev/null
+++ b/kernel/posix-cpu-timers.c
@@ -0,0 +1,1559 @@
+/*
+ * Implement CPU time clocks for the POSIX clock interface.
+ */
+
+#include <linux/sched.h>
+#include <linux/posix-timers.h>
+#include <asm/uaccess.h>
+#include <linux/errno.h>
+
+static int check_clock(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;
+
+ read_lock(&tasklist_lock);
+ p = find_task_by_pid(pid);
+ if (!p || (CPUCLOCK_PERTHREAD(which_clock) ?
+ p->tgid != current->tgid : p->tgid != pid)) {
+ error = -EINVAL;
+ }
+ read_unlock(&tasklist_lock);
+
+ return error;
+}
+
+static inline union cpu_time_count
+timespec_to_sample(clockid_t which_clock, const struct timespec *tp)
+{
+ union cpu_time_count ret;
+ ret.sched = 0; /* high half always zero when .cpu used */
+ if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
+ ret.sched = tp->tv_sec * NSEC_PER_SEC + tp->tv_nsec;
+ } else {
+ ret.cpu = timespec_to_cputime(tp);
+ }
+ return ret;
+}
+
+static void sample_to_timespec(clockid_t which_clock,
+ union cpu_time_count cpu,
+ struct timespec *tp)
+{
+ if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
+ tp->tv_sec = div_long_long_rem(cpu.sched,
+ NSEC_PER_SEC, &tp->tv_nsec);
+ } else {
+ cputime_to_timespec(cpu.cpu, tp);
+ }
+}
+
+static inline int cpu_time_before(clockid_t which_clock,
+ union cpu_time_count now,
+ union cpu_time_count then)
+{
+ if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
+ return now.sched < then.sched;
+ } else {
+ return cputime_lt(now.cpu, then.cpu);
+ }
+}
+static inline void cpu_time_add(clockid_t which_clock,
+ union cpu_time_count *acc,
+ union cpu_time_count val)
+{
+ if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
+ acc->sched += val.sched;
+ } else {
+ acc->cpu = cputime_add(acc->cpu, val.cpu);
+ }
+}
+static inline union cpu_time_count cpu_time_sub(clockid_t which_clock,
+ union cpu_time_count a,
+ union cpu_time_count b)
+{
+ if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
+ a.sched -= b.sched;
+ } else {
+ a.cpu = cputime_sub(a.cpu, b.cpu);
+ }
+ return a;
+}
+
+/*
+ * Update expiry time from increment, and increase overrun count,
+ * given the current clock sample.
+ */
+static inline void bump_cpu_timer(struct k_itimer *timer,
+ union cpu_time_count now)
+{
+ int i;
+
+ if (timer->it.cpu.incr.sched == 0)
+ return;
+
+ if (CPUCLOCK_WHICH(timer->it_clock) == CPUCLOCK_SCHED) {
+ unsigned long long delta, incr;
+
+ if (now.sched < timer->it.cpu.expires.sched)
+ return;
+ incr = timer->it.cpu.incr.sched;
+ delta = now.sched + incr - timer->it.cpu.expires.sched;
+ /* 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.sched += incr;
+ timer->it_overrun += 1 << i;
+ delta -= incr;
+ }
+ } else {
+ cputime_t delta, incr;
+
+ if (cputime_lt(now.cpu, timer->it.cpu.expires.cpu))
+ return;
+ incr = timer->it.cpu.incr.cpu;
+ delta = cputime_sub(cputime_add(now.cpu, incr),
+ timer->it.cpu.expires.cpu);
+ /* Don't use (incr*2 < delta), incr*2 might overflow. */
+ for (i = 0; cputime_lt(incr, cputime_sub(delta, incr)); i++)
+ incr = cputime_add(incr, incr);
+ for (; i >= 0; incr = cputime_halve(incr), i--) {
+ if (cputime_le(delta, incr))
+ continue;
+ timer->it.cpu.expires.cpu =
+ cputime_add(timer->it.cpu.expires.cpu, incr);
+ timer->it_overrun += 1 << i;
+ delta = cputime_sub(delta, incr);
+ }
+ }
+}
+
+static inline cputime_t prof_ticks(struct task_struct *p)
+{
+ return cputime_add(p->utime, p->stime);
+}
+static inline cputime_t virt_ticks(struct task_struct *p)
+{
+ return p->utime;
+}
+static inline unsigned long long sched_ns(struct task_struct *p)
+{
+ return (p == current) ? current_sched_time(p) : p->sched_time;
+}
+
+int posix_cpu_clock_getres(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;
+}
+
+int posix_cpu_clock_set(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(clockid_t which_clock, struct task_struct *p,
+ union cpu_time_count *cpu)
+{
+ switch (CPUCLOCK_WHICH(which_clock)) {
+ default:
+ return -EINVAL;
+ case CPUCLOCK_PROF:
+ cpu->cpu = prof_ticks(p);
+ break;
+ case CPUCLOCK_VIRT:
+ cpu->cpu = virt_ticks(p);
+ break;
+ case CPUCLOCK_SCHED:
+ cpu->sched = sched_ns(p);
+ break;
+ }
+ return 0;
+}
+
+/*
+ * Sample a process (thread group) clock for the given group_leader task.
+ * Must be called with tasklist_lock held for reading.
+ * Must be called with tasklist_lock held for reading, and p->sighand->siglock.
+ */
+static int cpu_clock_sample_group_locked(unsigned int clock_idx,
+ struct task_struct *p,
+ union cpu_time_count *cpu)
+{
+ struct task_struct *t = p;
+ switch (clock_idx) {
+ default:
+ return -EINVAL;
+ case CPUCLOCK_PROF:
+ cpu->cpu = cputime_add(p->signal->utime, p->signal->stime);
+ do {
+ cpu->cpu = cputime_add(cpu->cpu, prof_ticks(t));
+ t = next_thread(t);
+ } while (t != p);
+ break;
+ case CPUCLOCK_VIRT:
+ cpu->cpu = p->signal->utime;
+ do {
+ cpu->cpu = cputime_add(cpu->cpu, virt_ticks(t));
+ t = next_thread(t);
+ } while (t != p);
+ break;
+ case CPUCLOCK_SCHED:
+ cpu->sched = p->signal->sched_time;
+ /* Add in each other live thread. */
+ while ((t = next_thread(t)) != p) {
+ cpu->sched += t->sched_time;
+ }
+ if (p->tgid == current->tgid) {
+ /*
+ * We're sampling ourselves, so include the
+ * cycles not yet banked. We still omit
+ * other threads running on other CPUs,
+ * so the total can always be behind as
+ * much as max(nthreads-1,ncpus) * (NSEC_PER_SEC/HZ).
+ */
+ cpu->sched += current_sched_time(current);
+ } else {
+ cpu->sched += p->sched_time;
+ }
+ break;
+ }
+ return 0;
+}
+
+/*
+ * Sample a process (thread group) clock for the given group_leader task.
+ * Must be called with tasklist_lock held for reading.
+ */
+static int cpu_clock_sample_group(clockid_t which_clock,
+ struct task_struct *p,
+ union cpu_time_count *cpu)
+{
+ int ret;
+ unsigned long flags;
+ spin_lock_irqsave(&p->sighand->siglock, flags);
+ ret = cpu_clock_sample_group_locked(CPUCLOCK_WHICH(which_clock), p,
+ cpu);
+ spin_unlock_irqrestore(&p->sighand->siglock, flags);
+ return ret;
+}
+
+
+int posix_cpu_clock_get(clockid_t which_clock, struct timespec *tp)
+{
+ const pid_t pid = CPUCLOCK_PID(which_clock);
+ int error = -EINVAL;
+ union cpu_time_count rtn;
+
+ if (pid == 0) {
+ /*
+ * Special case constant value for our own clocks.
+ * We don't have to do any lookup to find ourselves.
+ */
+ if (CPUCLOCK_PERTHREAD(which_clock)) {
+ /*
+ * Sampling just ourselves we can do with no locking.
+ */
+ error = cpu_clock_sample(which_clock,
+ current, &rtn);
+ } else {
+ read_lock(&tasklist_lock);
+ error = cpu_clock_sample_group(which_clock,
+ current, &rtn);
+ read_unlock(&tasklist_lock);
+ }
+ } else {
+ /*
+ * Find the given PID, and validate that the caller
+ * should be able to see it.
+ */
+ struct task_struct *p;
+ read_lock(&tasklist_lock);
+ p = find_task_by_pid(pid);
+ if (p) {
+ if (CPUCLOCK_PERTHREAD(which_clock)) {
+ if (p->tgid == current->tgid) {
+ error = cpu_clock_sample(which_clock,
+ p, &rtn);
+ }
+ } else if (p->tgid == pid && p->signal) {
+ error = cpu_clock_sample_group(which_clock,
+ p, &rtn);
+ }
+ }
+ read_unlock(&tasklist_lock);
+ }
+
+ if (error)
+ return error;
+ sample_to_timespec(which_clock, rtn, tp);
+ return 0;
+}
+
+
+/*
+ * Validate the clockid_t for a new CPU-clock timer, and initialize the timer.
+ * This is called from sys_timer_create with the new timer already locked.
+ */
+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);
+ new_timer->it.cpu.incr.sched = 0;
+ new_timer->it.cpu.expires.sched = 0;
+
+ read_lock(&tasklist_lock);
+ if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) {
+ if (pid == 0) {
+ p = current;
+ } else {
+ p = find_task_by_pid(pid);
+ if (p && p->tgid != current->tgid)
+ p = NULL;
+ }
+ } else {
+ if (pid == 0) {
+ p = current->group_leader;
+ } else {
+ p = find_task_by_pid(pid);
+ if (p && p->tgid != pid)
+ p = NULL;
+ }
+ }
+ new_timer->it.cpu.task = p;
+ if (p) {
+ get_task_struct(p);
+ } else {
+ ret = -EINVAL;
+ }
+ read_unlock(&tasklist_lock);
+
+ 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.)
+ */
+int posix_cpu_timer_del(struct k_itimer *timer)
+{
+ struct task_struct *p = timer->it.cpu.task;
+
+ if (timer->it.cpu.firing)
+ return TIMER_RETRY;
+
+ if (unlikely(p == NULL))
+ return 0;
+
+ if (!list_empty(&timer->it.cpu.entry)) {
+ read_lock(&tasklist_lock);
+ if (unlikely(p->signal == NULL)) {
+ /*
+ * We raced with the reaping of the task.
+ * The deletion should have cleared us off the list.
+ */
+ BUG_ON(!list_empty(&timer->it.cpu.entry));
+ } else {
+ /*
+ * Take us off the task's timer list.
+ */
+ spin_lock(&p->sighand->siglock);
+ list_del(&timer->it.cpu.entry);
+ spin_unlock(&p->sighand->siglock);
+ }
+ read_unlock(&tasklist_lock);
+ }
+ put_task_struct(p);
+
+ return 0;
+}
+
+/*
+ * 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,
+ cputime_t utime, cputime_t stime,
+ unsigned long long sched_time)
+{
+ struct cpu_timer_list *timer, *next;
+ cputime_t ptime = cputime_add(utime, stime);
+
+ list_for_each_entry_safe(timer, next, head, entry) {
+ timer->task = NULL;
+ list_del_init(&timer->entry);
+ if (cputime_lt(timer->expires.cpu, ptime)) {
+ timer->expires.cpu = cputime_zero;
+ } else {
+ timer->expires.cpu = cputime_sub(timer->expires.cpu,
+ ptime);
+ }
+ }
+
+ ++head;
+ list_for_each_entry_safe(timer, next, head, entry) {
+ timer->task = NULL;
+ list_del_init(&timer->entry);
+ if (cputime_lt(timer->expires.cpu, utime)) {
+ timer->expires.cpu = cputime_zero;
+ } else {
+ timer->expires.cpu = cputime_sub(timer->expires.cpu,
+ utime);
+ }
+ }
+
+ ++head;
+ list_for_each_entry_safe(timer, next, head, entry) {
+ timer->task = NULL;
+ list_del_init(&timer->entry);
+ if (timer->expires.sched < sched_time) {
+ timer->expires.sched = 0;
+ } else {
+ timer->expires.sched -= sched_time;
+ }
+ }
+}
+
+/*
+ * 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)
+{
+ cleanup_timers(tsk->cpu_timers,
+ tsk->utime, tsk->stime, tsk->sched_time);
+
+}
+void posix_cpu_timers_exit_group(struct task_struct *tsk)
+{
+ cleanup_timers(tsk->signal->cpu_timers,
+ cputime_add(tsk->utime, tsk->signal->utime),
+ cputime_add(tsk->stime, tsk->signal->stime),
+ tsk->sched_time + tsk->signal->sched_time);
+}
+
+
+/*
+ * Set the expiry times of all the threads in the process so one of them
+ * will go off before the process cumulative expiry total is reached.
+ */
+static void process_timer_rebalance(struct task_struct *p,
+ unsigned int clock_idx,
+ union cpu_time_count expires,
+ union cpu_time_count val)
+{
+ cputime_t ticks, left;
+ unsigned long long ns, nsleft;
+ struct task_struct *t = p;
+ unsigned int nthreads = atomic_read(&p->signal->live);
+
+ switch (clock_idx) {
+ default:
+ BUG();
+ break;
+ case CPUCLOCK_PROF:
+ left = cputime_div(cputime_sub(expires.cpu, val.cpu),
+ nthreads);
+ do {
+ if (!unlikely(t->exit_state)) {
+ ticks = cputime_add(prof_ticks(t), left);
+ if (cputime_eq(t->it_prof_expires,
+ cputime_zero) ||
+ cputime_gt(t->it_prof_expires, ticks)) {
+ t->it_prof_expires = ticks;
+ }
+ }
+ t = next_thread(t);
+ } while (t != p);
+ break;
+ case CPUCLOCK_VIRT:
+ left = cputime_div(cputime_sub(expires.cpu, val.cpu),
+ nthreads);
+ do {
+ if (!unlikely(t->exit_state)) {
+ ticks = cputime_add(virt_ticks(t), left);
+ if (cputime_eq(t->it_virt_expires,
+ cputime_zero) ||
+ cputime_gt(t->it_virt_expires, ticks)) {
+ t->it_virt_expires = ticks;
+ }
+ }
+ t = next_thread(t);
+ } while (t != p);
+ break;
+ case CPUCLOCK_SCHED:
+ nsleft = expires.sched - val.sched;
+ do_div(nsleft, nthreads);
+ do {
+ if (!unlikely(t->exit_state)) {
+ ns = t->sched_time + nsleft;
+ if (t->it_sched_expires == 0 ||
+ t->it_sched_expires > ns) {
+ t->it_sched_expires = ns;
+ }
+ }
+ t = next_thread(t);
+ } while (t != p);
+ break;
+ }
+}
+
+static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now)
+{
+ /*
+ * That's all for this thread or process.
+ * We leave our residual in expires to be reported.
+ */
+ put_task_struct(timer->it.cpu.task);
+ timer->it.cpu.task = NULL;
+ timer->it.cpu.expires = cpu_time_sub(timer->it_clock,
+ timer->it.cpu.expires,
+ now);
+}
+
+/*
+ * Insert the timer on the appropriate list before any timers that
+ * expire later. This must be called with the tasklist_lock held
+ * for reading, and interrupts disabled.
+ */
+static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
+{
+ struct task_struct *p = timer->it.cpu.task;
+ struct list_head *head, *listpos;
+ struct cpu_timer_list *const nt = &timer->it.cpu;
+ struct cpu_timer_list *next;
+ unsigned long i;
+
+ head = (CPUCLOCK_PERTHREAD(timer->it_clock) ?
+ p->cpu_timers : p->signal->cpu_timers);
+ head += CPUCLOCK_WHICH(timer->it_clock);
+
+ BUG_ON(!irqs_disabled());
+ spin_lock(&p->sighand->siglock);
+
+ listpos = head;
+ if (CPUCLOCK_WHICH(timer->it_clock) == CPUCLOCK_SCHED) {
+ list_for_each_entry(next, head, entry) {
+ if (next->expires.sched > nt->expires.sched) {
+ listpos = &next->entry;
+ break;
+ }
+ }
+ } else {
+ list_for_each_entry(next, head, entry) {
+ if (cputime_gt(next->expires.cpu, nt->expires.cpu)) {
+ listpos = &next->entry;
+ break;
+ }
+ }
+ }
+ list_add(&nt->entry, listpos);
+
+ if (listpos == head) {
+ /*
+ * We are the new earliest-expiring timer.
+ * If we are a thread timer, there can always
+ * be a process timer telling us to stop earlier.
+ */
+
+ if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
+ switch (CPUCLOCK_WHICH(timer->it_clock)) {
+ default:
+ BUG();
+ case CPUCLOCK_PROF:
+ if (cputime_eq(p->it_prof_expires,
+ cputime_zero) ||
+ cputime_gt(p->it_prof_expires,
+ nt->expires.cpu))
+ p->it_prof_expires = nt->expires.cpu;
+ break;
+ case CPUCLOCK_VIRT:
+ if (cputime_eq(p->it_virt_expires,
+ cputime_zero) ||
+ cputime_gt(p->it_virt_expires,
+ nt->expires.cpu))
+ p->it_virt_expires = nt->expires.cpu;
+ break;
+ case CPUCLOCK_SCHED:
+ if (p->it_sched_expires == 0 ||
+ p->it_sched_expires > nt->expires.sched)
+ p->it_sched_expires = nt->expires.sched;
+ break;
+ }
+ } else {
+ /*
+ * For a process timer, we must balance
+ * all the live threads' expirations.
+ */
+ switch (CPUCLOCK_WHICH(timer->it_clock)) {
+ default:
+ BUG();
+ case CPUCLOCK_VIRT:
+ if (!cputime_eq(p->signal->it_virt_expires,
+ cputime_zero) &&
+ cputime_lt(p->signal->it_virt_expires,
+ timer->it.cpu.expires.cpu))
+ break;
+ goto rebalance;
+ case CPUCLOCK_PROF:
+ if (!cputime_eq(p->signal->it_prof_expires,
+ cputime_zero) &&
+ cputime_lt(p->signal->it_prof_expires,
+ timer->it.cpu.expires.cpu))
+ break;
+ i = p->signal->rlim[RLIMIT_CPU].rlim_cur;
+ if (i != RLIM_INFINITY &&
+ i <= cputime_to_secs(timer->it.cpu.expires.cpu))
+ break;
+ goto rebalance;
+ case CPUCLOCK_SCHED:
+ rebalance:
+ process_timer_rebalance(
+ timer->it.cpu.task,
+ CPUCLOCK_WHICH(timer->it_clock),
+ timer->it.cpu.expires, now);
+ break;
+ }
+ }
+ }
+
+ spin_unlock(&p->sighand->siglock);
+}
+
+/*
+ * The timer is locked, fire it and arrange for its reload.
+ */
+static void cpu_timer_fire(struct k_itimer *timer)
+{
+ 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.sched = 0;
+ } else if (timer->it.cpu.incr.sched == 0) {
+ /*
+ * One-shot timer. Clear it as soon as it's fired.
+ */
+ posix_timer_event(timer, 0);
+ timer->it.cpu.expires.sched = 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);
+ }
+}
+
+/*
+ * 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.)
+ */
+int posix_cpu_timer_set(struct k_itimer *timer, int flags,
+ struct itimerspec *new, struct itimerspec *old)
+{
+ struct task_struct *p = timer->it.cpu.task;
+ union cpu_time_count old_expires, new_expires, val;
+ int ret;
+
+ if (unlikely(p == NULL)) {
+ /*
+ * Timer refers to a dead task's clock.
+ */
+ return -ESRCH;
+ }
+
+ new_expires = timespec_to_sample(timer->it_clock, &new->it_value);
+
+ read_lock(&tasklist_lock);
+ /*
+ * We need the tasklist_lock to protect against reaping that
+ * clears p->signal. If p has just been reaped, we can no
+ * longer get any information about it at all.
+ */
+ if (unlikely(p->signal == NULL)) {
+ read_unlock(&tasklist_lock);
+ put_task_struct(p);
+ timer->it.cpu.task = NULL;
+ return -ESRCH;
+ }
+
+ /*
+ * Disarm any old timer after extracting its expiry time.
+ */
+ BUG_ON(!irqs_disabled());
+ spin_lock(&p->sighand->siglock);
+ old_expires = timer->it.cpu.expires;
+ list_del_init(&timer->it.cpu.entry);
+ spin_unlock(&p->sighand->siglock);
+
+ /*
+ * 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_clock_sample_group(timer->it_clock, p, &val);
+ }
+
+ if (old) {
+ if (old_expires.sched == 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 (cpu_time_before(timer->it_clock, val,
+ timer->it.cpu.expires)) {
+ old_expires = cpu_time_sub(
+ timer->it_clock,
+ 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(timer->it.cpu.firing)) {
+ /*
+ * 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).
+ */
+ read_unlock(&tasklist_lock);
+ timer->it.cpu.firing = -1;
+ ret = TIMER_RETRY;
+ goto out;
+ }
+
+ if (new_expires.sched != 0 && !(flags & TIMER_ABSTIME)) {
+ cpu_time_add(timer->it_clock, &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.sched != 0 &&
+ (timer->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE &&
+ cpu_time_before(timer->it_clock, val, new_expires)) {
+ arm_timer(timer, val);
+ }
+
+ read_unlock(&tasklist_lock);
+
+ /*
+ * 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.sched != 0 &&
+ (timer->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE &&
+ !cpu_time_before(timer->it_clock, 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,
+ timer->it.cpu.incr, &old->it_interval);
+ }
+ return ret;
+}
+
+void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
+{
+ union cpu_time_count now;
+ struct task_struct *p = timer->it.cpu.task;
+ int clear_dead;
+
+ /*
+ * Easy part: convert the reload time.
+ */
+ sample_to_timespec(timer->it_clock,
+ timer->it.cpu.incr, &itp->it_interval);
+
+ if (timer->it.cpu.expires.sched == 0) { /* Timer not armed at all. */
+ itp->it_value.tv_sec = itp->it_value.tv_nsec = 0;
+ return;
+ }
+
+ if (unlikely(p == NULL)) {
+ /*
+ * This task already died and the timer will never fire.
+ * In this case, expires is actually the dead value.
+ */
+ dead:
+ sample_to_timespec(timer->it_clock, timer->it.cpu.expires,
+ &itp->it_value);
+ 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);
+ clear_dead = p->exit_state;
+ } else {
+ read_lock(&tasklist_lock);
+ if (unlikely(p->signal == NULL)) {
+ /*
+ * The process has been reaped.
+ * We can't even collect a sample any more.
+ * Call the timer disarmed, nothing else to do.
+ */
+ put_task_struct(p);
+ timer->it.cpu.task = NULL;
+ timer->it.cpu.expires.sched = 0;
+ read_unlock(&tasklist_lock);
+ goto dead;
+ } else {
+ cpu_clock_sample_group(timer->it_clock, p, &now);
+ clear_dead = (unlikely(p->exit_state) &&
+ thread_group_empty(p));
+ }
+ read_unlock(&tasklist_lock);
+ }
+
+ if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
+ if (timer->it.cpu.incr.sched == 0 &&
+ cpu_time_before(timer->it_clock,
+ timer->it.cpu.expires, now)) {
+ /*
+ * Do-nothing timer expired and has no reload,
+ * so it's as if it was never set.
+ */
+ timer->it.cpu.expires.sched = 0;
+ itp->it_value.tv_sec = itp->it_value.tv_nsec = 0;
+ return;
+ }
+ /*
+ * Account for any expirations and reloads that should
+ * have happened.
+ */
+ bump_cpu_timer(timer, now);
+ }
+
+ if (unlikely(clear_dead)) {
+ /*
+ * We've noticed that the thread is dead, but
+ * not yet reaped. Take this opportunity to
+ * drop our task ref.
+ */
+ clear_dead_task(timer, now);
+ goto dead;
+ }
+
+ if (cpu_time_before(timer->it_clock, now, timer->it.cpu.expires)) {
+ sample_to_timespec(timer->it_clock,
+ cpu_time_sub(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;
+ }
+}
+
+/*
+ * 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;
+
+ tsk->it_prof_expires = cputime_zero;
+ while (!list_empty(timers)) {
+ struct cpu_timer_list *t = list_entry(timers->next,
+ struct cpu_timer_list,
+ entry);
+ if (cputime_lt(prof_ticks(tsk), t->expires.cpu)) {
+ tsk->it_prof_expires = t->expires.cpu;
+ break;
+ }
+ t->firing = 1;
+ list_move_tail(&t->entry, firing);
+ }
+
+ ++timers;
+ tsk->it_virt_expires = cputime_zero;
+ while (!list_empty(timers)) {
+ struct cpu_timer_list *t = list_entry(timers->next,
+ struct cpu_timer_list,
+ entry);
+ if (cputime_lt(virt_ticks(tsk), t->expires.cpu)) {
+ tsk->it_virt_expires = t->expires.cpu;
+ break;
+ }
+ t->firing = 1;
+ list_move_tail(&t->entry, firing);
+ }
+
+ ++timers;
+ tsk->it_sched_expires = 0;
+ while (!list_empty(timers)) {
+ struct cpu_timer_list *t = list_entry(timers->next,
+ struct cpu_timer_list,
+ entry);
+ if (tsk->sched_time < t->expires.sched) {
+ tsk->it_sched_expires = t->expires.sched;
+ break;
+ }
+ t->firing = 1;
+ list_move_tail(&t->entry, firing);
+ }
+}
+
+/*
+ * 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;
+ cputime_t utime, stime, ptime, virt_expires, prof_expires;
+ unsigned long long sched_time, sched_expires;
+ struct task_struct *t;
+ struct list_head *timers = sig->cpu_timers;
+
+ /*
+ * Don't sample the current process CPU clocks if there are no timers.
+ */
+ if (list_empty(&timers[CPUCLOCK_PROF]) &&
+ cputime_eq(sig->it_prof_expires, cputime_zero) &&
+ sig->rlim[RLIMIT_CPU].rlim_cur == RLIM_INFINITY &&
+ list_empty(&timers[CPUCLOCK_VIRT]) &&
+ cputime_eq(sig->it_virt_expires, cputime_zero) &&
+ list_empty(&timers[CPUCLOCK_SCHED]))
+ return;
+
+ /*
+ * Collect the current process totals.
+ */
+ utime = sig->utime;
+ stime = sig->stime;
+ sched_time = sig->sched_time;
+ t = tsk;
+ do {
+ utime = cputime_add(utime, t->utime);
+ stime = cputime_add(stime, t->stime);
+ sched_time += t->sched_time;
+ t = next_thread(t);
+ } while (t != tsk);
+ ptime = cputime_add(utime, stime);
+
+ prof_expires = cputime_zero;
+ while (!list_empty(timers)) {
+ struct cpu_timer_list *t = list_entry(timers->next,
+ struct cpu_timer_list,
+ entry);
+ if (cputime_lt(ptime, t->expires.cpu)) {
+ prof_expires = t->expires.cpu;
+ break;
+ }
+ t->firing = 1;
+ list_move_tail(&t->entry, firing);
+ }
+
+ ++timers;
+ virt_expires = cputime_zero;
+ while (!list_empty(timers)) {
+ struct cpu_timer_list *t = list_entry(timers->next,
+ struct cpu_timer_list,
+ entry);
+ if (cputime_lt(utime, t->expires.cpu)) {
+ virt_expires = t->expires.cpu;
+ break;
+ }
+ t->firing = 1;
+ list_move_tail(&t->entry, firing);
+ }
+
+ ++timers;
+ sched_expires = 0;
+ while (!list_empty(timers)) {
+ struct cpu_timer_list *t = list_entry(timers->next,
+ struct cpu_timer_list,
+ entry);
+ if (sched_time < t->expires.sched) {
+ sched_expires = t->expires.sched;
+ break;
+ }
+ t->firing = 1;
+ list_move_tail(&t->entry, firing);
+ }
+
+ /*
+ * Check for the special case process timers.
+ */
+ if (!cputime_eq(sig->it_prof_expires, cputime_zero)) {
+ if (cputime_ge(ptime, sig->it_prof_expires)) {
+ /* ITIMER_PROF fires and reloads. */
+ sig->it_prof_expires = sig->it_prof_incr;
+ if (!cputime_eq(sig->it_prof_expires, cputime_zero)) {
+ sig->it_prof_expires = cputime_add(
+ sig->it_prof_expires, ptime);
+ }
+ __group_send_sig_info(SIGPROF, SEND_SIG_PRIV, tsk);
+ }
+ if (!cputime_eq(sig->it_prof_expires, cputime_zero) &&
+ (cputime_eq(prof_expires, cputime_zero) ||
+ cputime_lt(sig->it_prof_expires, prof_expires))) {
+ prof_expires = sig->it_prof_expires;
+ }
+ }
+ if (!cputime_eq(sig->it_virt_expires, cputime_zero)) {
+ if (cputime_ge(utime, sig->it_virt_expires)) {
+ /* ITIMER_VIRTUAL fires and reloads. */
+ sig->it_virt_expires = sig->it_virt_incr;
+ if (!cputime_eq(sig->it_virt_expires, cputime_zero)) {
+ sig->it_virt_expires = cputime_add(
+ sig->it_virt_expires, utime);
+ }
+ __group_send_sig_info(SIGVTALRM, SEND_SIG_PRIV, tsk);
+ }
+ if (!cputime_eq(sig->it_virt_expires, cputime_zero) &&
+ (cputime_eq(virt_expires, cputime_zero) ||
+ cputime_lt(sig->it_virt_expires, virt_expires))) {
+ virt_expires = sig->it_virt_expires;
+ }
+ }
+ if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
+ unsigned long psecs = cputime_to_secs(ptime);
+ cputime_t x;
+ if (psecs >= sig->rlim[RLIMIT_CPU].rlim_max) {
+ /*
+ * 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 >= sig->rlim[RLIMIT_CPU].rlim_cur) {
+ /*
+ * At the soft limit, send a SIGXCPU every second.
+ */
+ __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
+ if (sig->rlim[RLIMIT_CPU].rlim_cur
+ < sig->rlim[RLIMIT_CPU].rlim_max) {
+ sig->rlim[RLIMIT_CPU].rlim_cur++;
+ }
+ }
+ x = secs_to_cputime(sig->rlim[RLIMIT_CPU].rlim_cur);
+ if (cputime_eq(prof_expires, cputime_zero) ||
+ cputime_lt(x, prof_expires)) {
+ prof_expires = x;
+ }
+ }
+
+ if (!cputime_eq(prof_expires, cputime_zero) ||
+ !cputime_eq(virt_expires, cputime_zero) ||
+ sched_expires != 0) {
+ /*
+ * Rebalance the threads' expiry times for the remaining
+ * process CPU timers.
+ */
+
+ cputime_t prof_left, virt_left, ticks;
+ unsigned long long sched_left, sched;
+ const unsigned int nthreads = atomic_read(&sig->live);
+
+ prof_left = cputime_sub(prof_expires, utime);
+ prof_left = cputime_sub(prof_left, stime);
+ prof_left = cputime_div(prof_left, nthreads);
+ virt_left = cputime_sub(virt_expires, utime);
+ virt_left = cputime_div(virt_left, nthreads);
+ if (sched_expires) {
+ sched_left = sched_expires - sched_time;
+ do_div(sched_left, nthreads);
+ } else {
+ sched_left = 0;
+ }
+ t = tsk;
+ do {
+ ticks = cputime_add(cputime_add(t->utime, t->stime),
+ prof_left);
+ if (!cputime_eq(prof_expires, cputime_zero) &&
+ (cputime_eq(t->it_prof_expires, cputime_zero) ||
+ cputime_gt(t->it_prof_expires, ticks))) {
+ t->it_prof_expires = ticks;
+ }
+
+ ticks = cputime_add(t->utime, virt_left);
+ if (!cputime_eq(virt_expires, cputime_zero) &&
+ (cputime_eq(t->it_virt_expires, cputime_zero) ||
+ cputime_gt(t->it_virt_expires, ticks))) {
+ t->it_virt_expires = ticks;
+ }
+
+ sched = t->sched_time + sched_left;
+ if (sched_expires && (t->it_sched_expires == 0 ||
+ t->it_sched_expires > sched)) {
+ t->it_sched_expires = sched;
+ }
+
+ do {
+ t = next_thread(t);
+ } while (unlikely(t->exit_state));
+ } while (t != tsk);
+ }
+}
+
+/*
+ * 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 task_struct *p = timer->it.cpu.task;
+ union cpu_time_count now;
+
+ if (unlikely(p == NULL))
+ /*
+ * The task was cleaned up already, no future firings.
+ */
+ return;
+
+ /*
+ * 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)) {
+ clear_dead_task(timer, now);
+ return;
+ }
+ read_lock(&tasklist_lock); /* arm_timer needs it. */
+ } else {
+ read_lock(&tasklist_lock);
+ if (unlikely(p->signal == NULL)) {
+ /*
+ * The process has been reaped.
+ * We can't even collect a sample any more.
+ */
+ put_task_struct(p);
+ timer->it.cpu.task = p = NULL;
+ timer->it.cpu.expires.sched = 0;
+ read_unlock(&tasklist_lock);
+ return;
+ } else if (unlikely(p->exit_state) && thread_group_empty(p)) {
+ /*
+ * We've noticed that the thread is dead, but
+ * not yet reaped. Take this opportunity to
+ * drop our task ref.
+ */
+ clear_dead_task(timer, now);
+ read_unlock(&tasklist_lock);
+ return;
+ }
+ cpu_clock_sample_group(timer->it_clock, p, &now);
+ bump_cpu_timer(timer, now);
+ /* Leave the tasklist_lock locked for the call below. */
+ }
+
+ /*
+ * Now re-arm for the new expiry time.
+ */
+ arm_timer(timer, now);
+
+ read_unlock(&tasklist_lock);
+}
+
+/*
+ * 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.
+ */
+void run_posix_cpu_timers(struct task_struct *tsk)
+{
+ LIST_HEAD(firing);
+ struct k_itimer *timer, *next;
+
+ BUG_ON(!irqs_disabled());
+
+#define UNEXPIRED(clock) \
+ (cputime_eq(tsk->it_##clock##_expires, cputime_zero) || \
+ cputime_lt(clock##_ticks(tsk), tsk->it_##clock##_expires))
+
+ if (UNEXPIRED(prof) && UNEXPIRED(virt) &&
+ (tsk->it_sched_expires == 0 ||
+ tsk->sched_time < tsk->it_sched_expires))
+ return;
+
+#undef UNEXPIRED
+
+ BUG_ON(tsk->exit_state);
+
+ /*
+ * Double-check with locks held.
+ */
+ read_lock(&tasklist_lock);
+ spin_lock(&tsk->sighand->siglock);
+
+ /*
+ * Here we take off tsk->cpu_timers[N] and tsk->signal->cpu_timers[N]
+ * all the timers that are firing, and put them on the firing list.
+ */
+ check_thread_timers(tsk, &firing);
+ 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.
+ */
+ spin_unlock(&tsk->sighand->siglock);
+ read_unlock(&tasklist_lock);
+
+ /*
+ * Now that all the timers on our list have the firing flag,
+ * noone 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 firing;
+ spin_lock(&timer->it_lock);
+ list_del_init(&timer->it.cpu.entry);
+ 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(firing >= 0)) {
+ cpu_timer_fire(timer);
+ }
+ spin_unlock(&timer->it_lock);
+ }
+}
+
+/*
+ * Set one of the process-wide special case CPU timers.
+ * The tasklist_lock and tsk->sighand->siglock must be held by the caller.
+ * The oldval argument is null for the RLIMIT_CPU timer, where *newval is
+ * absolute; non-null for ITIMER_*, where *newval is relative and we update
+ * it to be absolute, *oldval is absolute and we update it to be relative.
+ */
+void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
+ cputime_t *newval, cputime_t *oldval)
+{
+ union cpu_time_count now;
+ struct list_head *head;
+
+ BUG_ON(clock_idx == CPUCLOCK_SCHED);
+ cpu_clock_sample_group_locked(clock_idx, tsk, &now);
+
+ if (oldval) {
+ if (!cputime_eq(*oldval, cputime_zero)) {
+ if (cputime_le(*oldval, now.cpu)) {
+ /* Just about to fire. */
+ *oldval = jiffies_to_cputime(1);
+ } else {
+ *oldval = cputime_sub(*oldval, now.cpu);
+ }
+ }
+
+ if (cputime_eq(*newval, cputime_zero))
+ return;
+ *newval = cputime_add(*newval, now.cpu);
+
+ /*
+ * If the RLIMIT_CPU timer will expire before the
+ * ITIMER_PROF timer, we have nothing else to do.
+ */
+ if (tsk->signal->rlim[RLIMIT_CPU].rlim_cur
+ < cputime_to_secs(*newval))
+ return;
+ }
+
+ /*
+ * Check whether there are any process timers already set to fire
+ * before this one. If so, we don't have anything more to do.
+ */
+ head = &tsk->signal->cpu_timers[clock_idx];
+ if (list_empty(head) ||
+ cputime_ge(list_entry(head->next,
+ struct cpu_timer_list, entry)->expires.cpu,
+ *newval)) {
+ /*
+ * Rejigger each thread's expiry time so that one will
+ * notice before we hit the process-cumulative expiry time.
+ */
+ union cpu_time_count expires = { .sched = 0 };
+ expires.cpu = *newval;
+ process_timer_rebalance(tsk, clock_idx, expires, now);
+ }
+}
+
+static long posix_cpu_clock_nanosleep_restart(struct restart_block *);
+
+int posix_cpu_nsleep(clockid_t which_clock, int flags,
+ struct timespec *rqtp)
+{
+ struct restart_block *restart_block =
+ ¤t_thread_info()->restart_block;
+ struct k_itimer timer;
+ int error;
+
+ /*
+ * Diagnose required errors first.
+ */
+ if (CPUCLOCK_PERTHREAD(which_clock) &&
+ (CPUCLOCK_PID(which_clock) == 0 ||
+ CPUCLOCK_PID(which_clock) == current->pid))
+ return -EINVAL;
+
+ /*
+ * 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) {
+ struct timespec __user *rmtp;
+ static struct itimerspec zero_it;
+ struct itimerspec it = { .it_value = *rqtp,
+ .it_interval = {} };
+
+ 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.sched == 0) {
+ /*
+ * Our timer fired and was reset.
+ */
+ 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);
+ posix_cpu_timer_set(&timer, 0, &zero_it, &it);
+ 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;
+ }
+
+ /*
+ * Report back to the user the time still remaining.
+ */
+ rmtp = (struct timespec __user *) restart_block->arg1;
+ if (rmtp != NULL && !(flags & TIMER_ABSTIME) &&
+ copy_to_user(rmtp, &it.it_value, sizeof *rmtp))
+ return -EFAULT;
+
+ restart_block->fn = posix_cpu_clock_nanosleep_restart;
+ /* Caller already set restart_block->arg1 */
+ restart_block->arg0 = which_clock;
+ restart_block->arg2 = rqtp->tv_sec;
+ restart_block->arg3 = rqtp->tv_nsec;
+
+ error = -ERESTART_RESTARTBLOCK;
+ }
+
+ return error;
+}
+
+static long
+posix_cpu_clock_nanosleep_restart(struct restart_block *restart_block)
+{
+ clockid_t which_clock = restart_block->arg0;
+ struct timespec t = { .tv_sec = restart_block->arg2,
+ .tv_nsec = restart_block->arg3 };
+ restart_block->fn = do_no_restart_syscall;
+ return posix_cpu_nsleep(which_clock, TIMER_ABSTIME, &t);
+}
+
+
+#define PROCESS_CLOCK MAKE_PROCESS_CPUCLOCK(0, CPUCLOCK_SCHED)
+#define THREAD_CLOCK MAKE_THREAD_CPUCLOCK(0, CPUCLOCK_SCHED)
+
+static int process_cpu_clock_getres(clockid_t which_clock, struct timespec *tp)
+{
+ return posix_cpu_clock_getres(PROCESS_CLOCK, tp);
+}
+static int process_cpu_clock_get(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(clockid_t which_clock, int flags,
+ struct timespec *rqtp)
+{
+ return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp);
+}
+static int thread_cpu_clock_getres(clockid_t which_clock, struct timespec *tp)
+{
+ return posix_cpu_clock_getres(THREAD_CLOCK, tp);
+}
+static int thread_cpu_clock_get(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);
+}
+static int thread_cpu_nsleep(clockid_t which_clock, int flags,
+ struct timespec *rqtp)
+{
+ return -EINVAL;
+}
+
+static __init int init_posix_cpu_timers(void)
+{
+ struct k_clock process = {
+ .clock_getres = process_cpu_clock_getres,
+ .clock_get = process_cpu_clock_get,
+ .clock_set = do_posix_clock_nosettime,
+ .timer_create = process_cpu_timer_create,
+ .nsleep = process_cpu_nsleep,
+ };
+ struct k_clock thread = {
+ .clock_getres = thread_cpu_clock_getres,
+ .clock_get = thread_cpu_clock_get,
+ .clock_set = do_posix_clock_nosettime,
+ .timer_create = thread_cpu_timer_create,
+ .nsleep = thread_cpu_nsleep,
+ };
+
+ register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &process);
+ register_posix_clock(CLOCK_THREAD_CPUTIME_ID, &thread);
+
+ return 0;
+}
+__initcall(init_posix_cpu_timers);