diff options
Diffstat (limited to 'kernel/time/posix-timers.c')
| -rw-r--r-- | kernel/time/posix-timers.c | 1574 |
1 files changed, 1574 insertions, 0 deletions
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c new file mode 100644 index 000000000000..80a8a09a21a0 --- /dev/null +++ b/kernel/time/posix-timers.c @@ -0,0 +1,1574 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * 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 + * + * These are all the functions necessary to implement POSIX clocks & timers + */ +#include <linux/compat.h> +#include <linux/compiler.h> +#include <linux/init.h> +#include <linux/jhash.h> +#include <linux/interrupt.h> +#include <linux/list.h> +#include <linux/memblock.h> +#include <linux/nospec.h> +#include <linux/posix-clock.h> +#include <linux/posix-timers.h> +#include <linux/prctl.h> +#include <linux/sched/task.h> +#include <linux/slab.h> +#include <linux/syscalls.h> +#include <linux/time.h> +#include <linux/time_namespace.h> +#include <linux/uaccess.h> + +#include "timekeeping.h" +#include "posix-timers.h" + +/* + * Timers are managed in a hash table for lockless lookup. The hash key is + * constructed from current::signal and the timer ID and the timer is + * matched against current::signal and the timer ID when walking the hash + * bucket list. + * + * This allows checkpoint/restore to reconstruct the exact timer IDs for + * a process. + */ +struct timer_hash_bucket { + spinlock_t lock; + struct hlist_head head; +}; + +static struct { + struct timer_hash_bucket *buckets; + unsigned long mask; + struct kmem_cache *cache; +} __timer_data __ro_after_init __aligned(4*sizeof(long)); + +#define timer_buckets (__timer_data.buckets) +#define timer_hashmask (__timer_data.mask) +#define posix_timers_cache (__timer_data.cache) + +static const struct k_clock * const posix_clocks[]; +static const struct k_clock *clockid_to_kclock(const clockid_t id); +static const struct k_clock clock_realtime, clock_monotonic; + +#define TIMER_ANY_ID INT_MIN + +/* SIGEV_THREAD_ID cannot share a bit with the other SIGEV values. */ +#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 + +static struct k_itimer *__lock_timer(timer_t timer_id); + +#define lock_timer(tid) \ +({ struct k_itimer *__timr; \ + __cond_lock(&__timr->it_lock, __timr = __lock_timer(tid)); \ + __timr; \ +}) + +static inline void unlock_timer(struct k_itimer *timr) +{ + if (likely((timr))) + spin_unlock_irq(&timr->it_lock); +} + +#define scoped_timer_get_or_fail(_id) \ + scoped_cond_guard(lock_timer, return -EINVAL, _id) + +#define scoped_timer (scope) + +DEFINE_CLASS(lock_timer, struct k_itimer *, unlock_timer(_T), __lock_timer(id), timer_t id); +DEFINE_CLASS_IS_COND_GUARD(lock_timer); + +static struct timer_hash_bucket *hash_bucket(struct signal_struct *sig, unsigned int nr) +{ + return &timer_buckets[jhash2((u32 *)&sig, sizeof(sig) / sizeof(u32), nr) & timer_hashmask]; +} + +static struct k_itimer *posix_timer_by_id(timer_t id) +{ + struct signal_struct *sig = current->signal; + struct timer_hash_bucket *bucket = hash_bucket(sig, id); + struct k_itimer *timer; + + hlist_for_each_entry_rcu(timer, &bucket->head, t_hash) { + /* timer->it_signal can be set concurrently */ + if ((READ_ONCE(timer->it_signal) == sig) && (timer->it_id == id)) + return timer; + } + return NULL; +} + +static inline struct signal_struct *posix_sig_owner(const struct k_itimer *timer) +{ + unsigned long val = (unsigned long)timer->it_signal; + + /* + * Mask out bit 0, which acts as invalid marker to prevent + * posix_timer_by_id() detecting it as valid. + */ + return (struct signal_struct *)(val & ~1UL); +} + +static bool posix_timer_hashed(struct timer_hash_bucket *bucket, struct signal_struct *sig, + timer_t id) +{ + struct hlist_head *head = &bucket->head; + struct k_itimer *timer; + + hlist_for_each_entry_rcu(timer, head, t_hash, lockdep_is_held(&bucket->lock)) { + if ((posix_sig_owner(timer) == sig) && (timer->it_id == id)) + return true; + } + return false; +} + +static bool posix_timer_add_at(struct k_itimer *timer, struct signal_struct *sig, unsigned int id) +{ + struct timer_hash_bucket *bucket = hash_bucket(sig, id); + + scoped_guard (spinlock, &bucket->lock) { + /* + * Validate under the lock as this could have raced against + * another thread ending up with the same ID, which is + * highly unlikely, but possible. + */ + if (!posix_timer_hashed(bucket, sig, id)) { + /* + * Set the timer ID and the signal pointer to make + * it identifiable in the hash table. The signal + * pointer has bit 0 set to indicate that it is not + * yet fully initialized. posix_timer_hashed() + * masks this bit out, but the syscall lookup fails + * to match due to it being set. This guarantees + * that there can't be duplicate timer IDs handed + * out. + */ + timer->it_id = (timer_t)id; + timer->it_signal = (struct signal_struct *)((unsigned long)sig | 1UL); + hlist_add_head_rcu(&timer->t_hash, &bucket->head); + return true; + } + } + return false; +} + +static int posix_timer_add(struct k_itimer *timer, int req_id) +{ + struct signal_struct *sig = current->signal; + + if (unlikely(req_id != TIMER_ANY_ID)) { + if (!posix_timer_add_at(timer, sig, req_id)) + return -EBUSY; + + /* + * Move the ID counter past the requested ID, so that after + * switching back to normal mode the IDs are outside of the + * exact allocated region. That avoids ID collisions on the + * next regular timer_create() invocations. + */ + atomic_set(&sig->next_posix_timer_id, req_id + 1); + return req_id; + } + + for (unsigned int cnt = 0; cnt <= INT_MAX; cnt++) { + /* Get the next timer ID and clamp it to positive space */ + unsigned int id = atomic_fetch_inc(&sig->next_posix_timer_id) & INT_MAX; + + if (posix_timer_add_at(timer, sig, id)) + return id; + cond_resched(); + } + /* POSIX return code when no timer ID could be allocated */ + return -EAGAIN; +} + +static int posix_get_realtime_timespec(clockid_t which_clock, struct timespec64 *tp) +{ + ktime_get_real_ts64(tp); + return 0; +} + +static ktime_t posix_get_realtime_ktime(clockid_t which_clock) +{ + return ktime_get_real(); +} + +static int posix_clock_realtime_set(const clockid_t which_clock, + const struct timespec64 *tp) +{ + return do_sys_settimeofday64(tp, NULL); +} + +static int posix_clock_realtime_adj(const clockid_t which_clock, + struct __kernel_timex *t) +{ + return do_adjtimex(t); +} + +static int posix_get_monotonic_timespec(clockid_t which_clock, struct timespec64 *tp) +{ + ktime_get_ts64(tp); + timens_add_monotonic(tp); + return 0; +} + +static ktime_t posix_get_monotonic_ktime(clockid_t which_clock) +{ + return ktime_get(); +} + +static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec64 *tp) +{ + ktime_get_raw_ts64(tp); + timens_add_monotonic(tp); + return 0; +} + +static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec64 *tp) +{ + ktime_get_coarse_real_ts64(tp); + return 0; +} + +static int posix_get_monotonic_coarse(clockid_t which_clock, + struct timespec64 *tp) +{ + ktime_get_coarse_ts64(tp); + timens_add_monotonic(tp); + return 0; +} + +static int posix_get_coarse_res(const clockid_t which_clock, struct timespec64 *tp) +{ + *tp = ktime_to_timespec64(KTIME_LOW_RES); + return 0; +} + +static int posix_get_boottime_timespec(const clockid_t which_clock, struct timespec64 *tp) +{ + ktime_get_boottime_ts64(tp); + timens_add_boottime(tp); + return 0; +} + +static ktime_t posix_get_boottime_ktime(const clockid_t which_clock) +{ + return ktime_get_boottime(); +} + +static int posix_get_tai_timespec(clockid_t which_clock, struct timespec64 *tp) +{ + ktime_get_clocktai_ts64(tp); + return 0; +} + +static ktime_t posix_get_tai_ktime(clockid_t which_clock) +{ + return ktime_get_clocktai(); +} + +static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp) +{ + tp->tv_sec = 0; + tp->tv_nsec = hrtimer_resolution; + return 0; +} + +/* + * The siginfo si_overrun field and the return value of timer_getoverrun(2) + * are of type int. Clamp the overrun value to INT_MAX + */ +static inline int timer_overrun_to_int(struct k_itimer *timr) +{ + if (timr->it_overrun_last > (s64)INT_MAX) + return INT_MAX; + + return (int)timr->it_overrun_last; +} + +static void common_hrtimer_rearm(struct k_itimer *timr) +{ + struct hrtimer *timer = &timr->it.real.timer; + + timr->it_overrun += hrtimer_forward_now(timer, timr->it_interval); + hrtimer_restart(timer); +} + +static bool __posixtimer_deliver_signal(struct kernel_siginfo *info, struct k_itimer *timr) +{ + guard(spinlock)(&timr->it_lock); + + /* + * Check if the timer is still alive or whether it got modified + * since the signal was queued. In either case, don't rearm and + * drop the signal. + */ + if (timr->it_signal_seq != timr->it_sigqueue_seq || WARN_ON_ONCE(!posixtimer_valid(timr))) + return false; + + if (!timr->it_interval || WARN_ON_ONCE(timr->it_status != POSIX_TIMER_REQUEUE_PENDING)) + return true; + + timr->kclock->timer_rearm(timr); + timr->it_status = POSIX_TIMER_ARMED; + timr->it_overrun_last = timr->it_overrun; + timr->it_overrun = -1LL; + ++timr->it_signal_seq; + info->si_overrun = timer_overrun_to_int(timr); + return true; +} + +/* + * This function is called from the signal delivery code. It decides + * whether the signal should be dropped and rearms interval timers. The + * timer can be unconditionally accessed as there is a reference held on + * it. + */ +bool posixtimer_deliver_signal(struct kernel_siginfo *info, struct sigqueue *timer_sigq) +{ + struct k_itimer *timr = container_of(timer_sigq, struct k_itimer, sigq); + bool ret; + + /* + * Release siglock to ensure proper locking order versus + * timr::it_lock. Keep interrupts disabled. + */ + spin_unlock(¤t->sighand->siglock); + + ret = __posixtimer_deliver_signal(info, timr); + + /* Drop the reference which was acquired when the signal was queued */ + posixtimer_putref(timr); + + spin_lock(¤t->sighand->siglock); + return ret; +} + +void posix_timer_queue_signal(struct k_itimer *timr) +{ + lockdep_assert_held(&timr->it_lock); + + if (!posixtimer_valid(timr)) + return; + + timr->it_status = timr->it_interval ? POSIX_TIMER_REQUEUE_PENDING : POSIX_TIMER_DISARMED; + posixtimer_send_sigqueue(timr); +} + +/* + * This function gets called when a POSIX.1b interval timer expires from + * the HRTIMER interrupt (soft interrupt on RT kernels). + * + * Handles CLOCK_REALTIME, CLOCK_MONOTONIC, CLOCK_BOOTTIME and CLOCK_TAI + * based timers. + */ +static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer) +{ + struct k_itimer *timr = container_of(timer, struct k_itimer, it.real.timer); + + guard(spinlock_irqsave)(&timr->it_lock); + posix_timer_queue_signal(timr); + return HRTIMER_NORESTART; +} + +long posixtimer_create_prctl(unsigned long ctrl) +{ + switch (ctrl) { + case PR_TIMER_CREATE_RESTORE_IDS_OFF: + current->signal->timer_create_restore_ids = 0; + return 0; + case PR_TIMER_CREATE_RESTORE_IDS_ON: + current->signal->timer_create_restore_ids = 1; + return 0; + case PR_TIMER_CREATE_RESTORE_IDS_GET: + return current->signal->timer_create_restore_ids; + } + return -EINVAL; +} + +static struct pid *good_sigevent(sigevent_t * event) +{ + struct pid *pid = task_tgid(current); + struct task_struct *rtn; + + switch (event->sigev_notify) { + case SIGEV_SIGNAL | SIGEV_THREAD_ID: + pid = find_vpid(event->sigev_notify_thread_id); + rtn = pid_task(pid, PIDTYPE_PID); + if (!rtn || !same_thread_group(rtn, current)) + return NULL; + fallthrough; + case SIGEV_SIGNAL: + case SIGEV_THREAD: + if (event->sigev_signo <= 0 || event->sigev_signo > SIGRTMAX) + return NULL; + fallthrough; + case SIGEV_NONE: + return pid; + default: + return NULL; + } +} + +static struct k_itimer *alloc_posix_timer(void) +{ + struct k_itimer *tmr; + + if (unlikely(!posix_timers_cache)) + return NULL; + + tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL); + if (!tmr) + return tmr; + + if (unlikely(!posixtimer_init_sigqueue(&tmr->sigq))) { + kmem_cache_free(posix_timers_cache, tmr); + return NULL; + } + rcuref_init(&tmr->rcuref, 1); + return tmr; +} + +void posixtimer_free_timer(struct k_itimer *tmr) +{ + put_pid(tmr->it_pid); + if (tmr->sigq.ucounts) + dec_rlimit_put_ucounts(tmr->sigq.ucounts, UCOUNT_RLIMIT_SIGPENDING); + kfree_rcu(tmr, rcu); +} + +static void posix_timer_unhash_and_free(struct k_itimer *tmr) +{ + struct timer_hash_bucket *bucket = hash_bucket(posix_sig_owner(tmr), tmr->it_id); + + scoped_guard (spinlock, &bucket->lock) + hlist_del_rcu(&tmr->t_hash); + posixtimer_putref(tmr); +} + +static int common_timer_create(struct k_itimer *new_timer) +{ + hrtimer_setup(&new_timer->it.real.timer, posix_timer_fn, new_timer->it_clock, 0); + return 0; +} + +/* Create a POSIX.1b interval timer. */ +static int do_timer_create(clockid_t which_clock, struct sigevent *event, + timer_t __user *created_timer_id) +{ + const struct k_clock *kc = clockid_to_kclock(which_clock); + timer_t req_id = TIMER_ANY_ID; + struct k_itimer *new_timer; + int error, new_timer_id; + + if (!kc) + return -EINVAL; + if (!kc->timer_create) + return -EOPNOTSUPP; + + /* Special case for CRIU to restore timers with a given timer ID. */ + if (unlikely(current->signal->timer_create_restore_ids)) { + if (copy_from_user(&req_id, created_timer_id, sizeof(req_id))) + return -EFAULT; + /* Valid IDs are 0..INT_MAX */ + if ((unsigned int)req_id > INT_MAX) + return -EINVAL; + } + + new_timer = alloc_posix_timer(); + if (unlikely(!new_timer)) + return -EAGAIN; + + spin_lock_init(&new_timer->it_lock); + + /* + * Add the timer to the hash table. The timer is not yet valid + * after insertion, but has a unique ID allocated. + */ + new_timer_id = posix_timer_add(new_timer, req_id); + if (new_timer_id < 0) { + posixtimer_free_timer(new_timer); + return new_timer_id; + } + + new_timer->it_clock = which_clock; + new_timer->kclock = kc; + new_timer->it_overrun = -1LL; + + if (event) { + scoped_guard (rcu) + new_timer->it_pid = get_pid(good_sigevent(event)); + if (!new_timer->it_pid) { + error = -EINVAL; + goto out; + } + 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; + } else { + new_timer->it_sigev_notify = SIGEV_SIGNAL; + new_timer->sigq.info.si_signo = SIGALRM; + new_timer->sigq.info.si_value.sival_int = new_timer->it_id; + new_timer->it_pid = get_pid(task_tgid(current)); + } + + if (new_timer->it_sigev_notify & SIGEV_THREAD_ID) + new_timer->it_pid_type = PIDTYPE_PID; + else + new_timer->it_pid_type = PIDTYPE_TGID; + + 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; + } + /* + * After successful copy out, the timer ID is visible to user space + * now but not yet valid because new_timer::signal low order bit is 1. + * + * Complete the initialization with the clock specific create + * callback. + */ + error = kc->timer_create(new_timer); + if (error) + goto out; + + /* + * timer::it_lock ensures that __lock_timer() observes a fully + * initialized timer when it observes a valid timer::it_signal. + * + * sighand::siglock is required to protect signal::posix_timers. + */ + scoped_guard (spinlock_irq, &new_timer->it_lock) { + guard(spinlock)(¤t->sighand->siglock); + /* + * new_timer::it_signal contains the signal pointer with + * bit 0 set, which makes it invalid for syscall operations. + * Store the unmodified signal pointer to make it valid. + */ + WRITE_ONCE(new_timer->it_signal, current->signal); + hlist_add_head_rcu(&new_timer->list, ¤t->signal->posix_timers); + } + /* + * After unlocking @new_timer is subject to concurrent removal and + * cannot be touched anymore + */ + return 0; +out: + posix_timer_unhash_and_free(new_timer); + return error; +} + +SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock, + struct sigevent __user *, timer_event_spec, + timer_t __user *, created_timer_id) +{ + if (timer_event_spec) { + sigevent_t event; + + if (copy_from_user(&event, timer_event_spec, sizeof (event))) + return -EFAULT; + return do_timer_create(which_clock, &event, created_timer_id); + } + return do_timer_create(which_clock, NULL, created_timer_id); +} + +#ifdef CONFIG_COMPAT +COMPAT_SYSCALL_DEFINE3(timer_create, clockid_t, which_clock, + struct compat_sigevent __user *, timer_event_spec, + timer_t __user *, created_timer_id) +{ + if (timer_event_spec) { + sigevent_t event; + + if (get_compat_sigevent(&event, timer_event_spec)) + return -EFAULT; + return do_timer_create(which_clock, &event, created_timer_id); + } + return do_timer_create(which_clock, NULL, created_timer_id); +} +#endif + +static struct k_itimer *__lock_timer(timer_t timer_id) +{ + struct k_itimer *timr; + + /* + * timer_t could be any type >= int and we want to make sure any + * @timer_id outside positive int range fails lookup. + */ + if ((unsigned long long)timer_id > INT_MAX) + return NULL; + + /* + * The hash lookup and the timers are RCU protected. + * + * Timers are added to the hash in invalid state where + * timr::it_signal is marked invalid. timer::it_signal is only set + * after the rest of the initialization succeeded. + * + * Timer destruction happens in steps: + * 1) Set timr::it_signal marked invalid with timr::it_lock held + * 2) Release timr::it_lock + * 3) Remove from the hash under hash_lock + * 4) Put the reference count. + * + * The reference count might not drop to zero if timr::sigq is + * queued. In that case the signal delivery or flush will put the + * last reference count. + * + * When the reference count reaches zero, the timer is scheduled + * for RCU removal after the grace period. + * + * Holding rcu_read_lock() across the lookup ensures that + * the timer cannot be freed. + * + * The lookup validates locklessly that timr::it_signal == + * current::it_signal and timr::it_id == @timer_id. timr::it_id + * can't change, but timr::it_signal can become invalid during + * destruction, which makes the locked check fail. + */ + guard(rcu)(); + timr = posix_timer_by_id(timer_id); + if (timr) { + spin_lock_irq(&timr->it_lock); + /* + * Validate under timr::it_lock that timr::it_signal is + * still valid. Pairs with #1 above. + */ + if (timr->it_signal == current->signal) + return timr; + spin_unlock_irq(&timr->it_lock); + } + return NULL; +} + +static ktime_t common_hrtimer_remaining(struct k_itimer *timr, ktime_t now) +{ + struct hrtimer *timer = &timr->it.real.timer; + + return __hrtimer_expires_remaining_adjusted(timer, now); +} + +static s64 common_hrtimer_forward(struct k_itimer *timr, ktime_t now) +{ + struct hrtimer *timer = &timr->it.real.timer; + + return hrtimer_forward(timer, now, timr->it_interval); +} + +/* + * Get the time remaining on a POSIX.1b interval timer. + * + * Two issues to handle here: + * + * 1) The timer has a requeue pending. The return value must appear as + * if the timer has been requeued right now. + * + * 2) The timer is a SIGEV_NONE timer. These timers are never enqueued + * into the hrtimer queue and therefore never expired. Emulate expiry + * here taking #1 into account. + */ +void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting) +{ + const struct k_clock *kc = timr->kclock; + ktime_t now, remaining, iv; + bool sig_none; + + sig_none = timr->it_sigev_notify == SIGEV_NONE; + iv = timr->it_interval; + + /* interval timer ? */ + if (iv) { + cur_setting->it_interval = ktime_to_timespec64(iv); + } else if (timr->it_status == POSIX_TIMER_DISARMED) { + /* + * SIGEV_NONE oneshot timers are never queued and therefore + * timr->it_status is always DISARMED. The check below + * vs. remaining time will handle this case. + * + * For all other timers there is nothing to update here, so + * return. + */ + if (!sig_none) + return; + } + + now = kc->clock_get_ktime(timr->it_clock); + + /* + * If this is an interval timer and either has requeue pending or + * is a SIGEV_NONE timer move the expiry time forward by intervals, + * so expiry is > now. + */ + if (iv && timr->it_status != POSIX_TIMER_ARMED) + timr->it_overrun += kc->timer_forward(timr, now); + + remaining = kc->timer_remaining(timr, now); + /* + * As @now is retrieved before a possible timer_forward() and + * cannot be reevaluated by the compiler @remaining is based on the + * same @now value. Therefore @remaining is consistent vs. @now. + * + * Consequently all interval timers, i.e. @iv > 0, cannot have a + * remaining time <= 0 because timer_forward() guarantees to move + * them forward so that the next timer expiry is > @now. + */ + if (remaining <= 0) { + /* + * A single shot SIGEV_NONE timer must return 0, when it is + * expired! Timers which have a real signal delivery mode + * must return a remaining time greater than 0 because the + * signal has not yet been delivered. + */ + if (!sig_none) + cur_setting->it_value.tv_nsec = 1; + } else { + cur_setting->it_value = ktime_to_timespec64(remaining); + } +} + +static int do_timer_gettime(timer_t timer_id, struct itimerspec64 *setting) +{ + memset(setting, 0, sizeof(*setting)); + scoped_timer_get_or_fail(timer_id) + scoped_timer->kclock->timer_get(scoped_timer, setting); + return 0; +} + +/* Get the time remaining on a POSIX.1b interval timer. */ +SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id, + struct __kernel_itimerspec __user *, setting) +{ + struct itimerspec64 cur_setting; + + int ret = do_timer_gettime(timer_id, &cur_setting); + if (!ret) { + if (put_itimerspec64(&cur_setting, setting)) + ret = -EFAULT; + } + return ret; +} + +#ifdef CONFIG_COMPAT_32BIT_TIME + +SYSCALL_DEFINE2(timer_gettime32, timer_t, timer_id, + struct old_itimerspec32 __user *, setting) +{ + struct itimerspec64 cur_setting; + + int ret = do_timer_gettime(timer_id, &cur_setting); + if (!ret) { + if (put_old_itimerspec32(&cur_setting, setting)) + ret = -EFAULT; + } + return ret; +} + +#endif + +/** + * sys_timer_getoverrun - Get the number of overruns of a POSIX.1b interval timer + * @timer_id: The timer ID which identifies the timer + * + * The "overrun count" of a timer is one plus the number of expiration + * intervals which have elapsed between the first expiry, which queues the + * signal and the actual signal delivery. On signal delivery the "overrun + * count" is calculated and cached, so it can be returned directly here. + * + * As this is relative to the last queued signal the returned overrun count + * is meaningless outside of the signal delivery path and even there it + * does not accurately reflect the current state when user space evaluates + * it. + * + * Returns: + * -EINVAL @timer_id is invalid + * 1..INT_MAX The number of overruns related to the last delivered signal + */ +SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id) +{ + scoped_timer_get_or_fail(timer_id) + return timer_overrun_to_int(scoped_timer); +} + +static void common_hrtimer_arm(struct k_itimer *timr, ktime_t expires, + bool absolute, bool sigev_none) +{ + struct hrtimer *timer = &timr->it.real.timer; + enum hrtimer_mode mode; + + mode = absolute ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL; + /* + * Posix magic: Relative CLOCK_REALTIME timers are not affected by + * clock modifications, so they become CLOCK_MONOTONIC based under the + * hood. See hrtimer_setup(). Update timr->kclock, so the generic + * functions which use timr->kclock->clock_get_*() work. + * + * Note: it_clock stays unmodified, because the next timer_set() might + * use ABSTIME, so it needs to switch back. + */ + if (timr->it_clock == CLOCK_REALTIME) + timr->kclock = absolute ? &clock_realtime : &clock_monotonic; + + hrtimer_setup(&timr->it.real.timer, posix_timer_fn, timr->it_clock, mode); + + if (!absolute) + expires = ktime_add_safe(expires, hrtimer_cb_get_time(timer)); + hrtimer_set_expires(timer, expires); + + if (!sigev_none) + hrtimer_start_expires(timer, HRTIMER_MODE_ABS); +} + +static int common_hrtimer_try_to_cancel(struct k_itimer *timr) +{ + return hrtimer_try_to_cancel(&timr->it.real.timer); +} + +static void common_timer_wait_running(struct k_itimer *timer) +{ + hrtimer_cancel_wait_running(&timer->it.real.timer); +} + +/* + * On PREEMPT_RT this prevents priority inversion and a potential livelock + * against the ksoftirqd thread in case that ksoftirqd gets preempted while + * executing a hrtimer callback. + * + * See the comments in hrtimer_cancel_wait_running(). For PREEMPT_RT=n this + * just results in a cpu_relax(). + * + * For POSIX CPU timers with CONFIG_POSIX_CPU_TIMERS_TASK_WORK=n this is + * just a cpu_relax(). With CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y this + * prevents spinning on an eventually scheduled out task and a livelock + * when the task which tries to delete or disarm the timer has preempted + * the task which runs the expiry in task work context. + */ +static void timer_wait_running(struct k_itimer *timer) +{ + /* + * kc->timer_wait_running() might drop RCU lock. So @timer + * cannot be touched anymore after the function returns! + */ + timer->kclock->timer_wait_running(timer); +} + +/* + * Set up the new interval and reset the signal delivery data + */ +void posix_timer_set_common(struct k_itimer *timer, struct itimerspec64 *new_setting) +{ + if (new_setting->it_value.tv_sec || new_setting->it_value.tv_nsec) + timer->it_interval = timespec64_to_ktime(new_setting->it_interval); + else + timer->it_interval = 0; + + /* Reset overrun accounting */ + timer->it_overrun_last = 0; + timer->it_overrun = -1LL; +} + +/* Set a POSIX.1b interval timer. */ +int common_timer_set(struct k_itimer *timr, int flags, + struct itimerspec64 *new_setting, + struct itimerspec64 *old_setting) +{ + const struct k_clock *kc = timr->kclock; + bool sigev_none; + ktime_t expires; + + if (old_setting) + common_timer_get(timr, old_setting); + + /* + * Careful here. On SMP systems the timer expiry function could be + * active and spinning on timr->it_lock. + */ + if (kc->timer_try_to_cancel(timr) < 0) + return TIMER_RETRY; + + timr->it_status = POSIX_TIMER_DISARMED; + posix_timer_set_common(timr, new_setting); + + /* Keep timer disarmed when it_value is zero */ + if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec) + return 0; + + expires = timespec64_to_ktime(new_setting->it_value); + if (flags & TIMER_ABSTIME) + expires = timens_ktime_to_host(timr->it_clock, expires); + sigev_none = timr->it_sigev_notify == SIGEV_NONE; + + kc->timer_arm(timr, expires, flags & TIMER_ABSTIME, sigev_none); + if (!sigev_none) + timr->it_status = POSIX_TIMER_ARMED; + return 0; +} + +static int do_timer_settime(timer_t timer_id, int tmr_flags, struct itimerspec64 *new_spec64, + struct itimerspec64 *old_spec64) +{ + if (!timespec64_valid(&new_spec64->it_interval) || + !timespec64_valid(&new_spec64->it_value)) + return -EINVAL; + + if (old_spec64) + memset(old_spec64, 0, sizeof(*old_spec64)); + + for (; ; old_spec64 = NULL) { + struct k_itimer *timr; + + scoped_timer_get_or_fail(timer_id) { + timr = scoped_timer; + + if (old_spec64) + old_spec64->it_interval = ktime_to_timespec64(timr->it_interval); + + /* Prevent signal delivery and rearming. */ + timr->it_signal_seq++; + + int ret = timr->kclock->timer_set(timr, tmr_flags, new_spec64, old_spec64); + if (ret != TIMER_RETRY) + return ret; + + /* Protect the timer from being freed when leaving the lock scope */ + rcu_read_lock(); + } + timer_wait_running(timr); + rcu_read_unlock(); + } +} + +/* Set a POSIX.1b interval timer */ +SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags, + const struct __kernel_itimerspec __user *, new_setting, + struct __kernel_itimerspec __user *, old_setting) +{ + struct itimerspec64 new_spec, old_spec, *rtn; + int error = 0; + + if (!new_setting) + return -EINVAL; + + if (get_itimerspec64(&new_spec, new_setting)) + return -EFAULT; + + rtn = old_setting ? &old_spec : NULL; + error = do_timer_settime(timer_id, flags, &new_spec, rtn); + if (!error && old_setting) { + if (put_itimerspec64(&old_spec, old_setting)) + error = -EFAULT; + } + return error; +} + +#ifdef CONFIG_COMPAT_32BIT_TIME +SYSCALL_DEFINE4(timer_settime32, timer_t, timer_id, int, flags, + struct old_itimerspec32 __user *, new, + struct old_itimerspec32 __user *, old) +{ + struct itimerspec64 new_spec, old_spec; + struct itimerspec64 *rtn = old ? &old_spec : NULL; + int error = 0; + + if (!new) + return -EINVAL; + if (get_old_itimerspec32(&new_spec, new)) + return -EFAULT; + + error = do_timer_settime(timer_id, flags, &new_spec, rtn); + if (!error && old) { + if (put_old_itimerspec32(&old_spec, old)) + error = -EFAULT; + } + return error; +} +#endif + +int common_timer_del(struct k_itimer *timer) +{ + const struct k_clock *kc = timer->kclock; + + if (kc->timer_try_to_cancel(timer) < 0) + return TIMER_RETRY; + timer->it_status = POSIX_TIMER_DISARMED; + return 0; +} + +/* + * If the deleted timer is on the ignored list, remove it and + * drop the associated reference. + */ +static inline void posix_timer_cleanup_ignored(struct k_itimer *tmr) +{ + if (!hlist_unhashed(&tmr->ignored_list)) { + hlist_del_init(&tmr->ignored_list); + posixtimer_putref(tmr); + } +} + +static void posix_timer_delete(struct k_itimer *timer) +{ + /* + * Invalidate the timer, remove it from the linked list and remove + * it from the ignored list if pending. + * + * The invalidation must be written with siglock held so that the + * signal code observes the invalidated timer::it_signal in + * do_sigaction(), which prevents it from moving a pending signal + * of a deleted timer to the ignore list. + * + * The invalidation also prevents signal queueing, signal delivery + * and therefore rearming from the signal delivery path. + * + * A concurrent lookup can still find the timer in the hash, but it + * will check timer::it_signal with timer::it_lock held and observe + * bit 0 set, which invalidates it. That also prevents the timer ID + * from being handed out before this timer is completely gone. + */ + timer->it_signal_seq++; + + scoped_guard (spinlock, ¤t->sighand->siglock) { + unsigned long sig = (unsigned long)timer->it_signal | 1UL; + + WRITE_ONCE(timer->it_signal, (struct signal_struct *)sig); + hlist_del_rcu(&timer->list); + posix_timer_cleanup_ignored(timer); + } + + while (timer->kclock->timer_del(timer) == TIMER_RETRY) { + guard(rcu)(); + spin_unlock_irq(&timer->it_lock); + timer_wait_running(timer); + spin_lock_irq(&timer->it_lock); + } +} + +/* Delete a POSIX.1b interval timer. */ +SYSCALL_DEFINE1(timer_delete, timer_t, timer_id) +{ + struct k_itimer *timer; + + scoped_timer_get_or_fail(timer_id) { + timer = scoped_timer; + posix_timer_delete(timer); + } + /* Remove it from the hash, which frees up the timer ID */ + posix_timer_unhash_and_free(timer); + return 0; +} + +/* + * Invoked from do_exit() when the last thread of a thread group exits. + * At that point no other task can access the timers of the dying + * task anymore. + */ +void exit_itimers(struct task_struct *tsk) +{ + struct hlist_head timers; + struct hlist_node *next; + struct k_itimer *timer; + + /* Clear restore mode for exec() */ + tsk->signal->timer_create_restore_ids = 0; + + if (hlist_empty(&tsk->signal->posix_timers)) + return; + + /* Protect against concurrent read via /proc/$PID/timers */ + scoped_guard (spinlock_irq, &tsk->sighand->siglock) + hlist_move_list(&tsk->signal->posix_timers, &timers); + + /* The timers are not longer accessible via tsk::signal */ + hlist_for_each_entry_safe(timer, next, &timers, list) { + scoped_guard (spinlock_irq, &timer->it_lock) + posix_timer_delete(timer); + posix_timer_unhash_and_free(timer); + cond_resched(); + } + + /* + * There should be no timers on the ignored list. itimer_delete() has + * mopped them up. + */ + if (!WARN_ON_ONCE(!hlist_empty(&tsk->signal->ignored_posix_timers))) + return; + + hlist_move_list(&tsk->signal->ignored_posix_timers, &timers); + while (!hlist_empty(&timers)) { + posix_timer_cleanup_ignored(hlist_entry(timers.first, struct k_itimer, + ignored_list)); + } +} + +SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock, + const struct __kernel_timespec __user *, tp) +{ + const struct k_clock *kc = clockid_to_kclock(which_clock); + struct timespec64 new_tp; + + if (!kc || !kc->clock_set) + return -EINVAL; + + if (get_timespec64(&new_tp, tp)) + return -EFAULT; + + /* + * Permission checks have to be done inside the clock specific + * setter callback. + */ + return kc->clock_set(which_clock, &new_tp); +} + +SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock, + struct __kernel_timespec __user *, tp) +{ + const struct k_clock *kc = clockid_to_kclock(which_clock); + struct timespec64 kernel_tp; + int error; + + if (!kc) + return -EINVAL; + + error = kc->clock_get_timespec(which_clock, &kernel_tp); + + if (!error && put_timespec64(&kernel_tp, tp)) + error = -EFAULT; + + return error; +} + +int do_clock_adjtime(const clockid_t which_clock, struct __kernel_timex * ktx) +{ + const struct k_clock *kc = clockid_to_kclock(which_clock); + + if (!kc) + return -EINVAL; + if (!kc->clock_adj) + return -EOPNOTSUPP; + + return kc->clock_adj(which_clock, ktx); +} + +SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock, + struct __kernel_timex __user *, utx) +{ + struct __kernel_timex ktx; + int err; + + if (copy_from_user(&ktx, utx, sizeof(ktx))) + return -EFAULT; + + err = do_clock_adjtime(which_clock, &ktx); + + if (err >= 0 && copy_to_user(utx, &ktx, sizeof(ktx))) + return -EFAULT; + + return err; +} + +/** + * sys_clock_getres - Get the resolution of a clock + * @which_clock: The clock to get the resolution for + * @tp: Pointer to a a user space timespec64 for storage + * + * POSIX defines: + * + * "The clock_getres() function shall return the resolution of any + * clock. Clock resolutions are implementation-defined and cannot be set by + * a process. If the argument res is not NULL, the resolution of the + * specified clock shall be stored in the location pointed to by res. If + * res is NULL, the clock resolution is not returned. If the time argument + * of clock_settime() is not a multiple of res, then the value is truncated + * to a multiple of res." + * + * Due to the various hardware constraints the real resolution can vary + * wildly and even change during runtime when the underlying devices are + * replaced. The kernel also can use hardware devices with different + * resolutions for reading the time and for arming timers. + * + * The kernel therefore deviates from the POSIX spec in various aspects: + * + * 1) The resolution returned to user space + * + * For CLOCK_REALTIME, CLOCK_MONOTONIC, CLOCK_BOOTTIME, CLOCK_TAI, + * CLOCK_REALTIME_ALARM, CLOCK_BOOTTIME_ALAREM and CLOCK_MONOTONIC_RAW + * the kernel differentiates only two cases: + * + * I) Low resolution mode: + * + * When high resolution timers are disabled at compile or runtime + * the resolution returned is nanoseconds per tick, which represents + * the precision at which timers expire. + * + * II) High resolution mode: + * + * When high resolution timers are enabled the resolution returned + * is always one nanosecond independent of the actual resolution of + * the underlying hardware devices. + * + * For CLOCK_*_ALARM the actual resolution depends on system + * state. When system is running the resolution is the same as the + * resolution of the other clocks. During suspend the actual + * resolution is the resolution of the underlying RTC device which + * might be way less precise than the clockevent device used during + * running state. + * + * For CLOCK_REALTIME_COARSE and CLOCK_MONOTONIC_COARSE the resolution + * returned is always nanoseconds per tick. + * + * For CLOCK_PROCESS_CPUTIME and CLOCK_THREAD_CPUTIME the resolution + * returned is always one nanosecond under the assumption that the + * underlying scheduler clock has a better resolution than nanoseconds + * per tick. + * + * For dynamic POSIX clocks (PTP devices) the resolution returned is + * always one nanosecond. + * + * 2) Affect on sys_clock_settime() + * + * The kernel does not truncate the time which is handed in to + * sys_clock_settime(). The kernel internal timekeeping is always using + * nanoseconds precision independent of the clocksource device which is + * used to read the time from. The resolution of that device only + * affects the precision of the time returned by sys_clock_gettime(). + * + * Returns: + * 0 Success. @tp contains the resolution + * -EINVAL @which_clock is not a valid clock ID + * -EFAULT Copying the resolution to @tp faulted + * -ENODEV Dynamic POSIX clock is not backed by a device + * -EOPNOTSUPP Dynamic POSIX clock does not support getres() + */ +SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock, + struct __kernel_timespec __user *, tp) +{ + const struct k_clock *kc = clockid_to_kclock(which_clock); + struct timespec64 rtn_tp; + int error; + + if (!kc) + return -EINVAL; + + error = kc->clock_getres(which_clock, &rtn_tp); + + if (!error && tp && put_timespec64(&rtn_tp, tp)) + error = -EFAULT; + + return error; +} + +#ifdef CONFIG_COMPAT_32BIT_TIME + +SYSCALL_DEFINE2(clock_settime32, clockid_t, which_clock, + struct old_timespec32 __user *, tp) +{ + const struct k_clock *kc = clockid_to_kclock(which_clock); + struct timespec64 ts; + + if (!kc || !kc->clock_set) + return -EINVAL; + + if (get_old_timespec32(&ts, tp)) + return -EFAULT; + + return kc->clock_set(which_clock, &ts); +} + +SYSCALL_DEFINE2(clock_gettime32, clockid_t, which_clock, + struct old_timespec32 __user *, tp) +{ + const struct k_clock *kc = clockid_to_kclock(which_clock); + struct timespec64 ts; + int err; + + if (!kc) + return -EINVAL; + + err = kc->clock_get_timespec(which_clock, &ts); + + if (!err && put_old_timespec32(&ts, tp)) + err = -EFAULT; + + return err; +} + +SYSCALL_DEFINE2(clock_adjtime32, clockid_t, which_clock, + struct old_timex32 __user *, utp) +{ + struct __kernel_timex ktx; + int err; + + err = get_old_timex32(&ktx, utp); + if (err) + return err; + + err = do_clock_adjtime(which_clock, &ktx); + + if (err >= 0 && put_old_timex32(utp, &ktx)) + return -EFAULT; + + return err; +} + +SYSCALL_DEFINE2(clock_getres_time32, clockid_t, which_clock, + struct old_timespec32 __user *, tp) +{ + const struct k_clock *kc = clockid_to_kclock(which_clock); + struct timespec64 ts; + int err; + + if (!kc) + return -EINVAL; + + err = kc->clock_getres(which_clock, &ts); + if (!err && tp && put_old_timespec32(&ts, tp)) + return -EFAULT; + + return err; +} + +#endif + +/* + * sys_clock_nanosleep() for CLOCK_REALTIME and CLOCK_TAI + */ +static int common_nsleep(const clockid_t which_clock, int flags, + const struct timespec64 *rqtp) +{ + ktime_t texp = timespec64_to_ktime(*rqtp); + + return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ? + HRTIMER_MODE_ABS : HRTIMER_MODE_REL, + which_clock); +} + +/* + * sys_clock_nanosleep() for CLOCK_MONOTONIC and CLOCK_BOOTTIME + * + * Absolute nanosleeps for these clocks are time-namespace adjusted. + */ +static int common_nsleep_timens(const clockid_t which_clock, int flags, + const struct timespec64 *rqtp) +{ + ktime_t texp = timespec64_to_ktime(*rqtp); + + if (flags & TIMER_ABSTIME) + texp = timens_ktime_to_host(which_clock, texp); + + return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ? + HRTIMER_MODE_ABS : HRTIMER_MODE_REL, + which_clock); +} + +SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags, + const struct __kernel_timespec __user *, rqtp, + struct __kernel_timespec __user *, rmtp) +{ + const struct k_clock *kc = clockid_to_kclock(which_clock); + struct timespec64 t; + + if (!kc) + return -EINVAL; + if (!kc->nsleep) + return -EOPNOTSUPP; + + if (get_timespec64(&t, rqtp)) + return -EFAULT; + + if (!timespec64_valid(&t)) + return -EINVAL; + if (flags & TIMER_ABSTIME) + rmtp = NULL; + current->restart_block.fn = do_no_restart_syscall; + current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE; + current->restart_block.nanosleep.rmtp = rmtp; + + return kc->nsleep(which_clock, flags, &t); +} + +#ifdef CONFIG_COMPAT_32BIT_TIME + +SYSCALL_DEFINE4(clock_nanosleep_time32, clockid_t, which_clock, int, flags, + struct old_timespec32 __user *, rqtp, + struct old_timespec32 __user *, rmtp) +{ + const struct k_clock *kc = clockid_to_kclock(which_clock); + struct timespec64 t; + + if (!kc) + return -EINVAL; + if (!kc->nsleep) + return -EOPNOTSUPP; + + if (get_old_timespec32(&t, rqtp)) + return -EFAULT; + + if (!timespec64_valid(&t)) + return -EINVAL; + if (flags & TIMER_ABSTIME) + rmtp = NULL; + current->restart_block.fn = do_no_restart_syscall; + current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE; + current->restart_block.nanosleep.compat_rmtp = rmtp; + + return kc->nsleep(which_clock, flags, &t); +} + +#endif + +static const struct k_clock clock_realtime = { + .clock_getres = posix_get_hrtimer_res, + .clock_get_timespec = posix_get_realtime_timespec, + .clock_get_ktime = posix_get_realtime_ktime, + .clock_set = posix_clock_realtime_set, + .clock_adj = posix_clock_realtime_adj, + .nsleep = common_nsleep, + .timer_create = common_timer_create, + .timer_set = common_timer_set, + .timer_get = common_timer_get, + .timer_del = common_timer_del, + .timer_rearm = common_hrtimer_rearm, + .timer_forward = common_hrtimer_forward, + .timer_remaining = common_hrtimer_remaining, + .timer_try_to_cancel = common_hrtimer_try_to_cancel, + .timer_wait_running = common_timer_wait_running, + .timer_arm = common_hrtimer_arm, +}; + +static const struct k_clock clock_monotonic = { + .clock_getres = posix_get_hrtimer_res, + .clock_get_timespec = posix_get_monotonic_timespec, + .clock_get_ktime = posix_get_monotonic_ktime, + .nsleep = common_nsleep_timens, + .timer_create = common_timer_create, + .timer_set = common_timer_set, + .timer_get = common_timer_get, + .timer_del = common_timer_del, + .timer_rearm = common_hrtimer_rearm, + .timer_forward = common_hrtimer_forward, + .timer_remaining = common_hrtimer_remaining, + .timer_try_to_cancel = common_hrtimer_try_to_cancel, + .timer_wait_running = common_timer_wait_running, + .timer_arm = common_hrtimer_arm, +}; + +static const struct k_clock clock_monotonic_raw = { + .clock_getres = posix_get_hrtimer_res, + .clock_get_timespec = posix_get_monotonic_raw, +}; + +static const struct k_clock clock_realtime_coarse = { + .clock_getres = posix_get_coarse_res, + .clock_get_timespec = posix_get_realtime_coarse, +}; + +static const struct k_clock clock_monotonic_coarse = { + .clock_getres = posix_get_coarse_res, + .clock_get_timespec = posix_get_monotonic_coarse, +}; + +static const struct k_clock clock_tai = { + .clock_getres = posix_get_hrtimer_res, + .clock_get_ktime = posix_get_tai_ktime, + .clock_get_timespec = posix_get_tai_timespec, + .nsleep = common_nsleep, + .timer_create = common_timer_create, + .timer_set = common_timer_set, + .timer_get = common_timer_get, + .timer_del = common_timer_del, + .timer_rearm = common_hrtimer_rearm, + .timer_forward = common_hrtimer_forward, + .timer_remaining = common_hrtimer_remaining, + .timer_try_to_cancel = common_hrtimer_try_to_cancel, + .timer_wait_running = common_timer_wait_running, + .timer_arm = common_hrtimer_arm, +}; + +static const struct k_clock clock_boottime = { + .clock_getres = posix_get_hrtimer_res, + .clock_get_ktime = posix_get_boottime_ktime, + .clock_get_timespec = posix_get_boottime_timespec, + .nsleep = common_nsleep_timens, + .timer_create = common_timer_create, + .timer_set = common_timer_set, + .timer_get = common_timer_get, + .timer_del = common_timer_del, + .timer_rearm = common_hrtimer_rearm, + .timer_forward = common_hrtimer_forward, + .timer_remaining = common_hrtimer_remaining, + .timer_try_to_cancel = common_hrtimer_try_to_cancel, + .timer_wait_running = common_timer_wait_running, + .timer_arm = common_hrtimer_arm, +}; + +static const struct k_clock * const posix_clocks[] = { + [CLOCK_REALTIME] = &clock_realtime, + [CLOCK_MONOTONIC] = &clock_monotonic, + [CLOCK_PROCESS_CPUTIME_ID] = &clock_process, + [CLOCK_THREAD_CPUTIME_ID] = &clock_thread, + [CLOCK_MONOTONIC_RAW] = &clock_monotonic_raw, + [CLOCK_REALTIME_COARSE] = &clock_realtime_coarse, + [CLOCK_MONOTONIC_COARSE] = &clock_monotonic_coarse, + [CLOCK_BOOTTIME] = &clock_boottime, + [CLOCK_REALTIME_ALARM] = &alarm_clock, + [CLOCK_BOOTTIME_ALARM] = &alarm_clock, + [CLOCK_TAI] = &clock_tai, +#ifdef CONFIG_POSIX_AUX_CLOCKS + [CLOCK_AUX ... CLOCK_AUX_LAST] = &clock_aux, +#endif +}; + +static const struct k_clock *clockid_to_kclock(const clockid_t id) +{ + clockid_t idx = id; + + if (id < 0) { + return (id & CLOCKFD_MASK) == CLOCKFD ? + &clock_posix_dynamic : &clock_posix_cpu; + } + + if (id >= ARRAY_SIZE(posix_clocks)) + return NULL; + + return posix_clocks[array_index_nospec(idx, ARRAY_SIZE(posix_clocks))]; +} + +static int __init posixtimer_init(void) +{ + unsigned long i, size; + unsigned int shift; + + posix_timers_cache = kmem_cache_create("posix_timers_cache", + sizeof(struct k_itimer), + __alignof__(struct k_itimer), + SLAB_ACCOUNT, NULL); + + if (IS_ENABLED(CONFIG_BASE_SMALL)) + size = 512; + else + size = roundup_pow_of_two(512 * num_possible_cpus()); + + timer_buckets = alloc_large_system_hash("posixtimers", sizeof(*timer_buckets), + size, 0, 0, &shift, NULL, size, size); + size = 1UL << shift; + timer_hashmask = size - 1; + + for (i = 0; i < size; i++) { + spin_lock_init(&timer_buckets[i].lock); + INIT_HLIST_HEAD(&timer_buckets[i].head); + } + return 0; +} +core_initcall(posixtimer_init); |