/* * linux/kernel/posix-timers.c * * * 2002-10-15 Posix Clocks & timers * by George Anzinger george@mvista.com * * Copyright (C) 2002 2003 by MontaVista Software. * * 2004-06-01 Fix CLOCK_REALTIME clock/timer TIMER_ABSTIME bug. * Copyright (C) 2004 Boris Hu * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or (at * your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * MontaVista Software | 1237 East Arques Avenue | Sunnyvale | CA 94085 | USA */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static struct kmem_cache *posix_timers_cache; static struct idr posix_timers_id; static DEFINE_SPINLOCK(idr_lock); #if SIGEV_THREAD_ID != (SIGEV_THREAD_ID & \ ~(SIGEV_SIGNAL | SIGEV_NONE | SIGEV_THREAD)) #error "SIGEV_THREAD_ID must not share bit with other SIGEV values!" #endif #ifndef ENOTSUP # define ENANOSLEEP_NOTSUP EOPNOTSUPP #else # define ENANOSLEEP_NOTSUP ENOTSUP #endif /* * CLOCKs: The POSIX standard calls for a couple of clocks and allows us * to implement others. This structure defines the various * clocks. * * RESOLUTION: Clock resolution is used to round up timer and interval * times, NOT to report clock times, which are reported with as * much resolution as the system can muster. In some cases this * resolution may depend on the underlying clock hardware and * may not be quantifiable until run time, and only then is the * necessary code is written. The standard says we should say * something about this issue in the documentation... * * FUNCTIONS: The CLOCKs structure defines possible functions to * handle various clock functions. * * The standard POSIX timer management code assumes the * following: 1.) The k_itimer struct (sched.h) is used for * the timer. 2.) The list, it_lock, it_clock, it_id and * it_pid fields are not modified by timer code. * * Permissions: It is assumed that the clock_settime() function defined * for each clock will take care of permission checks. Some * clocks may be set able by any user (i.e. local process * clocks) others not. Currently the only set able clock we * have is CLOCK_REALTIME and its high res counter part, both of * which we beg off on and pass to do_sys_settimeofday(). */ static struct k_clock posix_clocks[MAX_CLOCKS]; static int common_nsleep(const clockid_t, int flags, struct timespec *t, struct timespec __user *rmtp); static int common_timer_create(struct k_itimer *new_timer); static void common_timer_get(struct k_itimer *, struct itimerspec *); static int common_timer_set(struct k_itimer *, int, struct itimerspec *, struct itimerspec *); static int common_timer_del(struct k_itimer *timer); static enum hrtimer_restart posix_timer_fn(struct hrtimer *data); static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags); #define lock_timer(tid, flags) \ ({ struct k_itimer *__timr; \ __cond_lock(&__timr->it_lock, __timr = __lock_timer(tid, flags)); \ __timr; \ }) static inline void unlock_timer(struct k_itimer *timr, unsigned long flags) { spin_unlock_irqrestore(&timr->it_lock, flags); } static int posix_clock_realtime_get(clockid_t which_clock, struct timespec *tp) { ktime_get_real_ts(tp); return 0; } static int posix_clock_realtime_set(const clockid_t which_clock, const struct timespec *tp) { return do_sys_settimeofday(tp, NULL); } static int posix_clock_realtime_adj(const clockid_t which_clock, struct timex *t) { return do_adjtimex(t); } static int posix_ktime_get_ts(clockid_t which_clock, struct timespec *tp) { ktime_get_ts(tp); return 0; } static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec *tp) { getrawmonotonic(tp); return 0; } static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec *tp) { *tp = current_kernel_time(); return 0; } static int posix_get_monotonic_coarse(clockid_t which_clock, struct timespec *tp) { *tp = get_monotonic_coarse(); return 0; } static int posix_get_coarse_res(const clockid_t which_clock, struct timespec *tp) { *tp = ktime_to_timespec(KTIME_LOW_RES); return 0; } static int posix_get_boottime(const clockid_t which_clock, struct timespec *tp) { get_monotonic_boottime(tp); return 0; } static __init int init_posix_timers(void) { struct k_clock clock_realtime = { .clock_getres = hrtimer_get_res, .clock_get = posix_clock_realtime_get, .clock_set = posix_clock_realtime_set, .clock_adj = posix_clock_realtime_adj, .nsleep = common_nsleep, .nsleep_restart = hrtimer_nanosleep_restart, .timer_create = common_timer_create, .timer_set = common_timer_set, .timer_get = common_timer_get, .timer_del = common_timer_del, }; struct k_clock clock_monotonic = { .clock_getres = hrtimer_get_res, .clock_get = posix_ktime_get_ts, .nsleep = common_nsleep, .nsleep_restart = hrtimer_nanosleep_restart, .timer_create = common_timer_create, .timer_set = common_timer_set, .timer_get = common_timer_get, .timer_del = common_timer_del, }; struct k_clock clock_monotonic_raw = { .clock_getres = hrtimer_get_res, .clock_get = posix_get_monotonic_raw, }; struct k_clock clock_realtime_coarse = { .clock_getres = posix_get_coarse_res, .clock_get = posix_get_realtime_coarse, }; struct k_clock clock_monotonic_coarse = { .clock_getres = posix_get_coarse_res, .clock_get = posix_get_monotonic_coarse, }; struct k_clock clock_boottime = { .clock_getres = hrtimer_get_res, .clock_get = posix_get_boottime, .nsleep = common_nsleep, .nsleep_restart = hrtimer_nanosleep_restart, .timer_create = common_timer_create, .timer_set = common_timer_set, .timer_get = common_timer_get, .timer_del = common_timer_del, }; posix_timers_register_clock(CLOCK_REALTIME, &clock_realtime); posix_timers_register_clock(CLOCK_MONOTONIC, &clock_monotonic); posix_timers_register_clock(CLOCK_MONOTONIC_RAW, &clock_monotonic_raw); posix_timers_register_clock(CLOCK_REALTIME_COARSE, &clock_realtime_coarse); posix_timers_register_clock(CLOCK_MONOTONIC_COARSE, &clock_monotonic_coarse); posix_timers_register_clock(CLOCK_BOOTTIME, &clock_boottime); posix_timers_cache = kmem_cache_create("posix_timers_cache", sizeof (struct k_itimer), 0, SLAB_PANIC, NULL); idr_init(&posix_timers_id); return 0; } __initcall(init_posix_timers); static void schedule_next_timer(struct k_itimer *timr) { struct hrtimer *timer = &timr->it.real.timer; if (timr->it.real.interval.tv64 == 0) return; timr->it_overrun += (unsigned int) hrtimer_forward(timer, timer->base->get_time(), timr->it.real.interval); timr->it_overrun_last = timr->it_overrun; timr->it_overrun = -1; ++timr->it_requeue_pending; hrtimer_restart(timer); } void do_schedule_next_timer(struct siginfo *info) { struct k_itimer *timr; unsigned long flags; timr = lock_timer(info->si_tid, &flags); if (timr && timr->it_requeue_pending == info->si_sys_private) { if (timr->it_clock < 0) posix_cpu_timer_schedule(timr); else schedule_next_timer(timr); info->si_overrun += timr->it_overrun_last; } if (timr) unlock_timer(timr, flags); } int posix_timer_event(struct k_itimer *timr, int si_private) { struct task_struct *task; int shared, ret = -1; timr->sigq->info.si_sys_private = si_private; rcu_read_lock(); task = pid_task(timr->it_pid, PIDTYPE_PID); if (task) { shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID); ret = send_sigqueue(timr->sigq, task, shared); } rcu_read_unlock(); return ret > 0; } EXPORT_SYMBOL_GPL(posix_timer_event); static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer) { struct k_itimer *timr; unsigned long flags; int si_private = 0; enum hrtimer_restart ret = HRTIMER_NORESTART; timr = container_of(timer, struct k_itimer, it.real.timer); spin_lock_irqsave(&timr->it_lock, flags); if (timr->it.real.interval.tv64 != 0) si_private = ++timr->it_requeue_pending; if (posix_timer_event(timr, si_private)) { if (timr->it.real.interval.tv64 != 0) { ktime_t now = hrtimer_cb_get_time(timer); #ifdef CONFIG_HIGH_RES_TIMERS { ktime_t kj = ktime_set(0, NSEC_PER_SEC / HZ); if (timr->it.real.interval.tv64 < kj.tv64) now = ktime_add(now, kj); } #endif timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, timr->it.real.interval); ret = HRTIMER_RESTART; ++timr->it_requeue_pending; } } unlock_timer(timr, flags); return ret; } static struct pid *good_sigevent(sigevent_t * event) { struct task_struct *rtn = current->group_leader; if ((event->sigev_notify & SIGEV_THREAD_ID ) && (!(rtn = find_task_by_vpid(event->sigev_notify_thread_id)) || !same_thread_group(rtn, current) || (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL)) return NULL; if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) && ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX))) return NULL; return task_pid(rtn); } void posix_timers_register_clock(const clockid_t clock_id, struct k_clock *new_clock) { if ((unsigned) clock_id >= MAX_CLOCKS) { printk(KERN_WARNING "POSIX clock register failed for clock_id %d\n", clock_id); return; } if (!new_clock->clock_get) { printk(KERN_WARNING "POSIX clock id %d lacks clock_get()\n", clock_id); return; } if (!new_clock->clock_getres) { printk(KERN_WARNING "POSIX clock id %d lacks clock_getres()\n", clock_id); return; } posix_clocks[clock_id] = *new_clock; } EXPORT_SYMBOL_GPL(posix_timers_register_clock); static struct k_itimer * alloc_posix_timer(void) { struct k_itimer *tmr; tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL); if (!tmr) return tmr; if (unlikely(!(tmr->sigq = sigqueue_alloc()))) { kmem_cache_free(posix_timers_cache, tmr); return NULL; } memset(&tmr->sigq->info, 0, sizeof(siginfo_t)); return tmr; } static void k_itimer_rcu_free(struct rcu_head *head) { struct k_itimer *tmr = container_of(head, struct k_itimer, it.rcu); kmem_cache_free(posix_timers_cache, tmr); } #define IT_ID_SET 1 #define IT_ID_NOT_SET 0 static void release_posix_timer(struct k_itimer *tmr, int it_id_set) { if (it_id_set) { unsigned long flags; spin_lock_irqsave(&idr_lock, flags); idr_remove(&posix_timers_id, tmr->it_id); spin_unlock_irqrestore(&idr_lock, flags); } put_pid(tmr->it_pid); sigqueue_free(tmr->sigq); call_rcu(&tmr->it.rcu, k_itimer_rcu_free); } static struct k_clock *clockid_to_kclock(const clockid_t id) { if (id < 0) return (id & CLOCKFD_MASK) == CLOCKFD ? &clock_posix_dynamic : &clock_posix_cpu; if (id >= MAX_CLOCKS || !posix_clocks[id].clock_getres) return NULL; return &posix_clocks[id]; } static int common_timer_create(struct k_itimer *new_timer) { hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0); return 0; } SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock, struct sigevent __user *, timer_event_spec, timer_t __user *, created_timer_id) { struct k_clock *kc = clockid_to_kclock(which_clock); struct k_itimer *new_timer; int error, new_timer_id; sigevent_t event; int it_id_set = IT_ID_NOT_SET; if (!kc) return -EINVAL; if (!kc->timer_create) return -EOPNOTSUPP; new_timer = alloc_posix_timer(); if (unlikely(!new_timer)) return -EAGAIN; spin_lock_init(&new_timer->it_lock); retry: if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) { error = -EAGAIN; goto out; } spin_lock_irq(&idr_lock); error = idr_get_new(&posix_timers_id, new_timer, &new_timer_id); spin_unlock_irq(&idr_lock); if (error) { if (error == -EAGAIN) goto retry; error = -EAGAIN; goto out; } it_id_set = IT_ID_SET; new_timer->it_id = (timer_t) new_timer_id; new_timer->it_clock = which_clock; new_timer->it_overrun = -1; if (timer_event_spec) { if (copy_from_user(&event, timer_event_spec, sizeof (event))) { error = -EFAULT; goto out; } rcu_read_lock(); new_timer->it_pid = get_pid(good_sigevent(&event)); rcu_read_unlock(); if (!new_timer->it_pid) { error = -EINVAL; goto out; } } else { event.sigev_notify = SIGEV_SIGNAL; event.sigev_signo = SIGALRM; event.sigev_value.sival_int = new_timer->it_id; new_timer->it_pid = get_pid(task_tgid(current)); } new_timer->it_sigev_notify = event.sigev_notify; new_timer->sigq->info.si_signo = event.sigev_signo; new_timer->sigq->info.si_value = event.sigev_value; new_timer->sigq->info.si_tid = new_timer->it_id; new_timer->sigq->info.si_code = SI_TIMER; if (copy_to_user(created_timer_id, &new_timer_id, sizeof (new_timer_id))) { error = -EFAULT; goto out; } error = kc->timer_create(new_timer); if (error) goto out; spin_lock_irq(¤t->sighand->siglock); new_timer->it_signal = current->signal; list_add(&new_timer->list, ¤t->signal->posix_timers); spin_unlock_irq(¤t->sighand->siglock); return 0; out: release_posix_timer(new_timer, it_id_set); return error; } static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags) { struct k_itimer *timr; rcu_read_lock(); timr = idr_find(&posix_timers_id, (int)timer_id); if (timr) { spin_lock_irqsave(&timr->it_lock, *flags); if (timr->it_signal == current->signal) { rcu_read_unlock(); return timr; } spin_unlock_irqrestore(&timr->it_lock, *flags); } rcu_read_unlock(); return NULL; } static void common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting) { ktime_t now, remaining, iv; struct hrtimer *timer = &timr->it.real.timer; memset(cur_setting, 0, sizeof(struct itimerspec)); iv = timr->it.real.interval; if (iv.tv64) cur_setting->it_interval = ktime_to_timespec(iv); else if (!hrtimer_active(timer) && (timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) return; now = timer->base->get_time(); if (iv.tv64 && (timr->it_requeue_pending & REQUEUE_PENDING || (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, iv); remaining = ktime_sub(hrtimer_get_expires(timer), now); if (remaining.tv64 <= 0) { if ((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) cur_setting->it_value.tv_nsec = 1; } else cur_setting->it_value = ktime_to_timespec(remaining); } SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id, struct itimerspec __user *, setting) { struct itimerspec cur_setting; struct k_itimer *timr; struct k_clock *kc; unsigned long flags; int ret = 0; timr = lock_timer(timer_id, &flags); if (!timr) return -EINVAL; kc = clockid_to_kclock(timr->it_clock); if (WARN_ON_ONCE(!kc || !kc->timer_get)) ret = -EINVAL; else kc->timer_get(timr, &cur_setting); unlock_timer(timr, flags); if (!ret && copy_to_user(setting, &cur_setting, sizeof (cur_setting))) return -EFAULT; return ret; } SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id) { struct k_itimer *timr; int overrun; unsigned long flags; timr = lock_timer(timer_id, &flags); if (!timr) return -EINVAL; overrun = timr->it_overrun_last; unlock_timer(timr, flags); return overrun; } static int common_timer_set(struct k_itimer *timr, int flags, struct itimerspec *new_setting, struct itimerspec *old_setting) { struct hrtimer *timer = &timr->it.real.timer; enum hrtimer_mode mode; if (old_setting) common_timer_get(timr, old_setting); timr->it.real.interval.tv64 = 0; if (hrtimer_try_to_cancel(timer) < 0) return TIMER_RETRY; timr->it_requeue_pending = (timr->it_requeue_pending + 2) & ~REQUEUE_PENDING; timr->it_overrun_last = 0; if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec) return 0; mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL; hrtimer_init(&timr->it.real.timer, timr->it_clock, mode); timr->it.real.timer.function = posix_timer_fn; hrtimer_set_expires(timer, timespec_to_ktime(new_setting->it_value)); timr->it.real.interval = timespec_to_ktime(new_setting->it_interval); if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) { if (mode == HRTIMER_MODE_REL) { hrtimer_add_expires(timer, timer->base->get_time()); } return 0; } hrtimer_start_expires(timer, mode); return 0; } SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags, const struct itimerspec __user *, new_setting, struct itimerspec __user *, old_setting) { struct k_itimer *timr; struct itimerspec new_spec, old_spec; int error = 0; unsigned long flag; struct itimerspec *rtn = old_setting ? &old_spec : NULL; struct k_clock *kc; if (!new_setting) return -EINVAL; if (copy_from_user(&new_spec, new_setting, sizeof (new_spec))) return -EFAULT; if (!timespec_valid(&new_spec.it_interval) || !timespec_valid(&new_spec.it_value)) return -EINVAL; retry: timr = lock_timer(timer_id, &flag); if (!timr) return -EINVAL; kc = clockid_to_kclock(timr->it_clock); if (WARN_ON_ONCE(!kc || !kc->timer_set)) error = -EINVAL; else error = kc->timer_set(timr, flags, &new_spec, rtn); unlock_timer(timr, flag); if (error == TIMER_RETRY) { rtn = NULL; goto retry; } if (old_setting && !error && copy_to_user(old_setting, &old_spec, sizeof (old_spec))) error = -EFAULT; return error; } static int common_timer_del(struct k_itimer *timer) { timer->it.real.interval.tv64 = 0; if (hrtimer_try_to_cancel(&timer->it.real.timer) < 0) return TIMER_RETRY; return 0; } static inline int timer_delete_hook(struct k_itimer *timer) { struct k_clock *kc = clockid_to_kclock(timer->it_clock); if (WARN_ON_ONCE(!kc || !kc->timer_del)) return -EINVAL; return kc->timer_del(timer); } SYSCALL_DEFINE1(timer_delete, timer_t, timer_id) { struct k_itimer *timer; unsigned long flags; retry_delete: timer = lock_timer(timer_id, &flags); if (!timer) return -EINVAL; if (timer_delete_hook(timer) == TIMER_RETRY) { unlock_timer(timer, flags); goto retry_delete; } spin_lock(¤t->sighand->siglock); list_del(&timer->list); spin_unlock(¤t->sighand->siglock); timer->it_signal = NULL; unlock_timer(timer, flags); release_posix_timer(timer, IT_ID_SET); return 0; } static void itimer_delete(struct k_itimer *timer) { unsigned long flags; retry_delete: spin_lock_irqsave(&timer->it_lock, flags); if (timer_delete_hook(timer) == TIMER_RETRY) { unlock_timer(timer, flags); goto retry_delete; } list_del(&timer->list); timer->it_signal = NULL; unlock_timer(timer, flags); release_posix_timer(timer, IT_ID_SET); } void exit_itimers(struct signal_struct *sig) { struct k_itimer *tmr; while (!list_empty(&sig->posix_timers)) { tmr = list_entry(sig->posix_timers.next, struct k_itimer, list); itimer_delete(tmr); } } SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock, const struct timespec __user *, tp) { struct k_clock *kc = clockid_to_kclock(which_clock); struct timespec new_tp; if (!kc || !kc->clock_set) return -EINVAL; if (copy_from_user(&new_tp, tp, sizeof (*tp))) return -EFAULT; return kc->clock_set(which_clock, &new_tp); } SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock, struct timespec __user *,tp) { struct k_clock *kc = clockid_to_kclock(which_clock); struct timespec kernel_tp; int error; if (!kc) return -EINVAL; error = kc->clock_get(which_clock, &kernel_tp); if (!error && copy_to_user(tp, &kernel_tp, sizeof (kernel_tp))) error = -EFAULT; return error; } SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock, struct timex __user *, utx) { struct k_clock *kc = clockid_to_kclock(which_clock); struct timex ktx; int err; if (!kc) return -EINVAL; if (!kc->clock_adj) return -EOPNOTSUPP; if (copy_from_user(&ktx, utx, sizeof(ktx))) return -EFAULT; err = kc->clock_adj(which_clock, &ktx); if (!err && copy_to_user(utx, &ktx, sizeof(ktx))) return -EFAULT; return err; } SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock, struct timespec __user *, tp) { struct k_clock *kc = clockid_to_kclock(which_clock); struct timespec rtn_tp; int error; if (!kc) return -EINVAL; error = kc->clock_getres(which_clock, &rtn_tp); if (!error && tp && copy_to_user(tp, &rtn_tp, sizeof (rtn_tp))) error = -EFAULT; return error; } static int common_nsleep(const clockid_t which_clock, int flags, struct timespec *tsave, struct timespec __user *rmtp) { return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL, which_clock); } SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags, const struct timespec __user *, rqtp, struct timespec __user *, rmtp) { struct k_clock *kc = clockid_to_kclock(which_clock); struct timespec t; if (!kc) return -EINVAL; if (!kc->nsleep) return -ENANOSLEEP_NOTSUP; if (copy_from_user(&t, rqtp, sizeof (struct timespec))) return -EFAULT; if (!timespec_valid(&t)) return -EINVAL; return kc->nsleep(which_clock, flags, &t, rmtp); } long clock_nanosleep_restart(struct restart_block *restart_block) { clockid_t which_clock = restart_block->nanosleep.clockid; struct k_clock *kc = clockid_to_kclock(which_clock); if (WARN_ON_ONCE(!kc || !kc->nsleep_restart)) return -EINVAL; return kc->nsleep_restart(restart_block); }