diff options
Diffstat (limited to 'kernel/time/posix-cpu-timers.c')
| -rw-r--r-- | kernel/time/posix-cpu-timers.c | 1692 |
1 files changed, 1692 insertions, 0 deletions
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c new file mode 100644 index 0000000000..e9c6f9d0e4 --- /dev/null +++ b/kernel/time/posix-cpu-timers.c @@ -0,0 +1,1692 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Implement CPU time clocks for the POSIX clock interface. + */ + +#include <linux/sched/signal.h> +#include <linux/sched/cputime.h> +#include <linux/posix-timers.h> +#include <linux/errno.h> +#include <linux/math64.h> +#include <linux/uaccess.h> +#include <linux/kernel_stat.h> +#include <trace/events/timer.h> +#include <linux/tick.h> +#include <linux/workqueue.h> +#include <linux/compat.h> +#include <linux/sched/deadline.h> +#include <linux/task_work.h> + +#include "posix-timers.h" + +static void posix_cpu_timer_rearm(struct k_itimer *timer); + +void posix_cputimers_group_init(struct posix_cputimers *pct, u64 cpu_limit) +{ + posix_cputimers_init(pct); + if (cpu_limit != RLIM_INFINITY) { + pct->bases[CPUCLOCK_PROF].nextevt = cpu_limit * NSEC_PER_SEC; + pct->timers_active = true; + } +} + +/* + * Called after updating RLIMIT_CPU to run cpu timer and update + * tsk->signal->posix_cputimers.bases[clock].nextevt expiration cache if + * necessary. Needs siglock protection since other code may update the + * expiration cache as well. + * + * Returns 0 on success, -ESRCH on failure. Can fail if the task is exiting and + * we cannot lock_task_sighand. Cannot fail if task is current. + */ +int update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new) +{ + u64 nsecs = rlim_new * NSEC_PER_SEC; + unsigned long irq_fl; + + if (!lock_task_sighand(task, &irq_fl)) + return -ESRCH; + set_process_cpu_timer(task, CPUCLOCK_PROF, &nsecs, NULL); + unlock_task_sighand(task, &irq_fl); + return 0; +} + +/* + * Functions for validating access to tasks. + */ +static struct pid *pid_for_clock(const clockid_t clock, bool gettime) +{ + const bool thread = !!CPUCLOCK_PERTHREAD(clock); + const pid_t upid = CPUCLOCK_PID(clock); + struct pid *pid; + + if (CPUCLOCK_WHICH(clock) >= CPUCLOCK_MAX) + return NULL; + + /* + * If the encoded PID is 0, then the timer is targeted at current + * or the process to which current belongs. + */ + if (upid == 0) + return thread ? task_pid(current) : task_tgid(current); + + pid = find_vpid(upid); + if (!pid) + return NULL; + + if (thread) { + struct task_struct *tsk = pid_task(pid, PIDTYPE_PID); + return (tsk && same_thread_group(tsk, current)) ? pid : NULL; + } + + /* + * For clock_gettime(PROCESS) allow finding the process by + * with the pid of the current task. The code needs the tgid + * of the process so that pid_task(pid, PIDTYPE_TGID) can be + * used to find the process. + */ + if (gettime && (pid == task_pid(current))) + return task_tgid(current); + + /* + * For processes require that pid identifies a process. + */ + return pid_has_task(pid, PIDTYPE_TGID) ? pid : NULL; +} + +static inline int validate_clock_permissions(const clockid_t clock) +{ + int ret; + + rcu_read_lock(); + ret = pid_for_clock(clock, false) ? 0 : -EINVAL; + rcu_read_unlock(); + + return ret; +} + +static inline enum pid_type clock_pid_type(const clockid_t clock) +{ + return CPUCLOCK_PERTHREAD(clock) ? PIDTYPE_PID : PIDTYPE_TGID; +} + +static inline struct task_struct *cpu_timer_task_rcu(struct k_itimer *timer) +{ + return pid_task(timer->it.cpu.pid, clock_pid_type(timer->it_clock)); +} + +/* + * Update expiry time from increment, and increase overrun count, + * given the current clock sample. + */ +static u64 bump_cpu_timer(struct k_itimer *timer, u64 now) +{ + u64 delta, incr, expires = timer->it.cpu.node.expires; + int i; + + if (!timer->it_interval) + return expires; + + if (now < expires) + return expires; + + incr = timer->it_interval; + delta = now + incr - expires; + + /* Don't use (incr*2 < delta), incr*2 might overflow. */ + for (i = 0; incr < delta - incr; i++) + incr = incr << 1; + + for (; i >= 0; incr >>= 1, i--) { + if (delta < incr) + continue; + + timer->it.cpu.node.expires += incr; + timer->it_overrun += 1LL << i; + delta -= incr; + } + return timer->it.cpu.node.expires; +} + +/* Check whether all cache entries contain U64_MAX, i.e. eternal expiry time */ +static inline bool expiry_cache_is_inactive(const struct posix_cputimers *pct) +{ + return !(~pct->bases[CPUCLOCK_PROF].nextevt | + ~pct->bases[CPUCLOCK_VIRT].nextevt | + ~pct->bases[CPUCLOCK_SCHED].nextevt); +} + +static int +posix_cpu_clock_getres(const clockid_t which_clock, struct timespec64 *tp) +{ + int error = validate_clock_permissions(which_clock); + + if (!error) { + tp->tv_sec = 0; + tp->tv_nsec = ((NSEC_PER_SEC + HZ - 1) / HZ); + if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { + /* + * If sched_clock is using a cycle counter, we + * don't have any idea of its true resolution + * exported, but it is much more than 1s/HZ. + */ + tp->tv_nsec = 1; + } + } + return error; +} + +static int +posix_cpu_clock_set(const clockid_t clock, const struct timespec64 *tp) +{ + int error = validate_clock_permissions(clock); + + /* + * You can never reset a CPU clock, but we check for other errors + * in the call before failing with EPERM. + */ + return error ? : -EPERM; +} + +/* + * Sample a per-thread clock for the given task. clkid is validated. + */ +static u64 cpu_clock_sample(const clockid_t clkid, struct task_struct *p) +{ + u64 utime, stime; + + if (clkid == CPUCLOCK_SCHED) + return task_sched_runtime(p); + + task_cputime(p, &utime, &stime); + + switch (clkid) { + case CPUCLOCK_PROF: + return utime + stime; + case CPUCLOCK_VIRT: + return utime; + default: + WARN_ON_ONCE(1); + } + return 0; +} + +static inline void store_samples(u64 *samples, u64 stime, u64 utime, u64 rtime) +{ + samples[CPUCLOCK_PROF] = stime + utime; + samples[CPUCLOCK_VIRT] = utime; + samples[CPUCLOCK_SCHED] = rtime; +} + +static void task_sample_cputime(struct task_struct *p, u64 *samples) +{ + u64 stime, utime; + + task_cputime(p, &utime, &stime); + store_samples(samples, stime, utime, p->se.sum_exec_runtime); +} + +static void proc_sample_cputime_atomic(struct task_cputime_atomic *at, + u64 *samples) +{ + u64 stime, utime, rtime; + + utime = atomic64_read(&at->utime); + stime = atomic64_read(&at->stime); + rtime = atomic64_read(&at->sum_exec_runtime); + store_samples(samples, stime, utime, rtime); +} + +/* + * Set cputime to sum_cputime if sum_cputime > cputime. Use cmpxchg + * to avoid race conditions with concurrent updates to cputime. + */ +static inline void __update_gt_cputime(atomic64_t *cputime, u64 sum_cputime) +{ + u64 curr_cputime = atomic64_read(cputime); + + do { + if (sum_cputime <= curr_cputime) + return; + } while (!atomic64_try_cmpxchg(cputime, &curr_cputime, sum_cputime)); +} + +static void update_gt_cputime(struct task_cputime_atomic *cputime_atomic, + struct task_cputime *sum) +{ + __update_gt_cputime(&cputime_atomic->utime, sum->utime); + __update_gt_cputime(&cputime_atomic->stime, sum->stime); + __update_gt_cputime(&cputime_atomic->sum_exec_runtime, sum->sum_exec_runtime); +} + +/** + * thread_group_sample_cputime - Sample cputime for a given task + * @tsk: Task for which cputime needs to be started + * @samples: Storage for time samples + * + * Called from sys_getitimer() to calculate the expiry time of an active + * timer. That means group cputime accounting is already active. Called + * with task sighand lock held. + * + * Updates @times with an uptodate sample of the thread group cputimes. + */ +void thread_group_sample_cputime(struct task_struct *tsk, u64 *samples) +{ + struct thread_group_cputimer *cputimer = &tsk->signal->cputimer; + struct posix_cputimers *pct = &tsk->signal->posix_cputimers; + + WARN_ON_ONCE(!pct->timers_active); + + proc_sample_cputime_atomic(&cputimer->cputime_atomic, samples); +} + +/** + * thread_group_start_cputime - Start cputime and return a sample + * @tsk: Task for which cputime needs to be started + * @samples: Storage for time samples + * + * The thread group cputime accounting is avoided when there are no posix + * CPU timers armed. Before starting a timer it's required to check whether + * the time accounting is active. If not, a full update of the atomic + * accounting store needs to be done and the accounting enabled. + * + * Updates @times with an uptodate sample of the thread group cputimes. + */ +static void thread_group_start_cputime(struct task_struct *tsk, u64 *samples) +{ + struct thread_group_cputimer *cputimer = &tsk->signal->cputimer; + struct posix_cputimers *pct = &tsk->signal->posix_cputimers; + + lockdep_assert_task_sighand_held(tsk); + + /* Check if cputimer isn't running. This is accessed without locking. */ + if (!READ_ONCE(pct->timers_active)) { + struct task_cputime sum; + + /* + * The POSIX timer interface allows for absolute time expiry + * values through the TIMER_ABSTIME flag, therefore we have + * to synchronize the timer to the clock every time we start it. + */ + thread_group_cputime(tsk, &sum); + update_gt_cputime(&cputimer->cputime_atomic, &sum); + + /* + * We're setting timers_active without a lock. Ensure this + * only gets written to in one operation. We set it after + * update_gt_cputime() as a small optimization, but + * barriers are not required because update_gt_cputime() + * can handle concurrent updates. + */ + WRITE_ONCE(pct->timers_active, true); + } + proc_sample_cputime_atomic(&cputimer->cputime_atomic, samples); +} + +static void __thread_group_cputime(struct task_struct *tsk, u64 *samples) +{ + struct task_cputime ct; + + thread_group_cputime(tsk, &ct); + store_samples(samples, ct.stime, ct.utime, ct.sum_exec_runtime); +} + +/* + * Sample a process (thread group) clock for the given task clkid. If the + * group's cputime accounting is already enabled, read the atomic + * store. Otherwise a full update is required. clkid is already validated. + */ +static u64 cpu_clock_sample_group(const clockid_t clkid, struct task_struct *p, + bool start) +{ + struct thread_group_cputimer *cputimer = &p->signal->cputimer; + struct posix_cputimers *pct = &p->signal->posix_cputimers; + u64 samples[CPUCLOCK_MAX]; + + if (!READ_ONCE(pct->timers_active)) { + if (start) + thread_group_start_cputime(p, samples); + else + __thread_group_cputime(p, samples); + } else { + proc_sample_cputime_atomic(&cputimer->cputime_atomic, samples); + } + + return samples[clkid]; +} + +static int posix_cpu_clock_get(const clockid_t clock, struct timespec64 *tp) +{ + const clockid_t clkid = CPUCLOCK_WHICH(clock); + struct task_struct *tsk; + u64 t; + + rcu_read_lock(); + tsk = pid_task(pid_for_clock(clock, true), clock_pid_type(clock)); + if (!tsk) { + rcu_read_unlock(); + return -EINVAL; + } + + if (CPUCLOCK_PERTHREAD(clock)) + t = cpu_clock_sample(clkid, tsk); + else + t = cpu_clock_sample_group(clkid, tsk, false); + rcu_read_unlock(); + + *tp = ns_to_timespec64(t); + return 0; +} + +/* + * Validate the clockid_t for a new CPU-clock timer, and initialize the timer. + * This is called from sys_timer_create() and do_cpu_nanosleep() with the + * new timer already all-zeros initialized. + */ +static int posix_cpu_timer_create(struct k_itimer *new_timer) +{ + static struct lock_class_key posix_cpu_timers_key; + struct pid *pid; + + rcu_read_lock(); + pid = pid_for_clock(new_timer->it_clock, false); + if (!pid) { + rcu_read_unlock(); + return -EINVAL; + } + + /* + * If posix timer expiry is handled in task work context then + * timer::it_lock can be taken without disabling interrupts as all + * other locking happens in task context. This requires a separate + * lock class key otherwise regular posix timer expiry would record + * the lock class being taken in interrupt context and generate a + * false positive warning. + */ + if (IS_ENABLED(CONFIG_POSIX_CPU_TIMERS_TASK_WORK)) + lockdep_set_class(&new_timer->it_lock, &posix_cpu_timers_key); + + new_timer->kclock = &clock_posix_cpu; + timerqueue_init(&new_timer->it.cpu.node); + new_timer->it.cpu.pid = get_pid(pid); + rcu_read_unlock(); + return 0; +} + +static struct posix_cputimer_base *timer_base(struct k_itimer *timer, + struct task_struct *tsk) +{ + int clkidx = CPUCLOCK_WHICH(timer->it_clock); + + if (CPUCLOCK_PERTHREAD(timer->it_clock)) + return tsk->posix_cputimers.bases + clkidx; + else + return tsk->signal->posix_cputimers.bases + clkidx; +} + +/* + * Force recalculating the base earliest expiration on the next tick. + * This will also re-evaluate the need to keep around the process wide + * cputime counter and tick dependency and eventually shut these down + * if necessary. + */ +static void trigger_base_recalc_expires(struct k_itimer *timer, + struct task_struct *tsk) +{ + struct posix_cputimer_base *base = timer_base(timer, tsk); + + base->nextevt = 0; +} + +/* + * Dequeue the timer and reset the base if it was its earliest expiration. + * It makes sure the next tick recalculates the base next expiration so we + * don't keep the costly process wide cputime counter around for a random + * amount of time, along with the tick dependency. + * + * If another timer gets queued between this and the next tick, its + * expiration will update the base next event if necessary on the next + * tick. + */ +static void disarm_timer(struct k_itimer *timer, struct task_struct *p) +{ + struct cpu_timer *ctmr = &timer->it.cpu; + struct posix_cputimer_base *base; + + if (!cpu_timer_dequeue(ctmr)) + return; + + base = timer_base(timer, p); + if (cpu_timer_getexpires(ctmr) == base->nextevt) + trigger_base_recalc_expires(timer, p); +} + + +/* + * Clean up a CPU-clock timer that is about to be destroyed. + * This is called from timer deletion with the timer already locked. + * If we return TIMER_RETRY, it's necessary to release the timer's lock + * and try again. (This happens when the timer is in the middle of firing.) + */ +static int posix_cpu_timer_del(struct k_itimer *timer) +{ + struct cpu_timer *ctmr = &timer->it.cpu; + struct sighand_struct *sighand; + struct task_struct *p; + unsigned long flags; + int ret = 0; + + rcu_read_lock(); + p = cpu_timer_task_rcu(timer); + if (!p) + goto out; + + /* + * Protect against sighand release/switch in exit/exec and process/ + * thread timer list entry concurrent read/writes. + */ + sighand = lock_task_sighand(p, &flags); + if (unlikely(sighand == NULL)) { + /* + * This raced with the reaping of the task. The exit cleanup + * should have removed this timer from the timer queue. + */ + WARN_ON_ONCE(ctmr->head || timerqueue_node_queued(&ctmr->node)); + } else { + if (timer->it.cpu.firing) + ret = TIMER_RETRY; + else + disarm_timer(timer, p); + + unlock_task_sighand(p, &flags); + } + +out: + rcu_read_unlock(); + if (!ret) + put_pid(ctmr->pid); + + return ret; +} + +static void cleanup_timerqueue(struct timerqueue_head *head) +{ + struct timerqueue_node *node; + struct cpu_timer *ctmr; + + while ((node = timerqueue_getnext(head))) { + timerqueue_del(head, node); + ctmr = container_of(node, struct cpu_timer, node); + ctmr->head = NULL; + } +} + +/* + * Clean out CPU timers which are still armed when a thread exits. The + * timers are only removed from the list. No other updates are done. The + * corresponding posix timers are still accessible, but cannot be rearmed. + * + * This must be called with the siglock held. + */ +static void cleanup_timers(struct posix_cputimers *pct) +{ + cleanup_timerqueue(&pct->bases[CPUCLOCK_PROF].tqhead); + cleanup_timerqueue(&pct->bases[CPUCLOCK_VIRT].tqhead); + cleanup_timerqueue(&pct->bases[CPUCLOCK_SCHED].tqhead); +} + +/* + * 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->posix_cputimers); +} +void posix_cpu_timers_exit_group(struct task_struct *tsk) +{ + cleanup_timers(&tsk->signal->posix_cputimers); +} + +/* + * Insert the timer on the appropriate list before any timers that + * expire later. This must be called with the sighand lock held. + */ +static void arm_timer(struct k_itimer *timer, struct task_struct *p) +{ + struct posix_cputimer_base *base = timer_base(timer, p); + struct cpu_timer *ctmr = &timer->it.cpu; + u64 newexp = cpu_timer_getexpires(ctmr); + + if (!cpu_timer_enqueue(&base->tqhead, ctmr)) + return; + + /* + * We are the new earliest-expiring POSIX 1.b timer, hence + * need to update expiration cache. Take into account that + * for process timers we share expiration cache with itimers + * and RLIMIT_CPU and for thread timers with RLIMIT_RTTIME. + */ + if (newexp < base->nextevt) + base->nextevt = newexp; + + if (CPUCLOCK_PERTHREAD(timer->it_clock)) + tick_dep_set_task(p, TICK_DEP_BIT_POSIX_TIMER); + else + tick_dep_set_signal(p, TICK_DEP_BIT_POSIX_TIMER); +} + +/* + * The timer is locked, fire it and arrange for its reload. + */ +static void cpu_timer_fire(struct k_itimer *timer) +{ + struct cpu_timer *ctmr = &timer->it.cpu; + + if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) { + /* + * User don't want any signal. + */ + cpu_timer_setexpires(ctmr, 0); + } else if (unlikely(timer->sigq == NULL)) { + /* + * This a special case for clock_nanosleep, + * not a normal timer from sys_timer_create. + */ + wake_up_process(timer->it_process); + cpu_timer_setexpires(ctmr, 0); + } else if (!timer->it_interval) { + /* + * One-shot timer. Clear it as soon as it's fired. + */ + posix_timer_event(timer, 0); + cpu_timer_setexpires(ctmr, 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_rearm(timer); + ++timer->it_requeue_pending; + } +} + +/* + * Guts of sys_timer_settime for CPU timers. + * This is called with the timer locked and interrupts disabled. + * If we return TIMER_RETRY, it's necessary to release the timer's lock + * and try again. (This happens when the timer is in the middle of firing.) + */ +static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags, + struct itimerspec64 *new, struct itimerspec64 *old) +{ + clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock); + u64 old_expires, new_expires, old_incr, val; + struct cpu_timer *ctmr = &timer->it.cpu; + struct sighand_struct *sighand; + struct task_struct *p; + unsigned long flags; + int ret = 0; + + rcu_read_lock(); + p = cpu_timer_task_rcu(timer); + if (!p) { + /* + * If p has just been reaped, we can no + * longer get any information about it at all. + */ + rcu_read_unlock(); + return -ESRCH; + } + + /* + * Use the to_ktime conversion because that clamps the maximum + * value to KTIME_MAX and avoid multiplication overflows. + */ + new_expires = ktime_to_ns(timespec64_to_ktime(new->it_value)); + + /* + * Protect against sighand release/switch in exit/exec and p->cpu_timers + * and p->signal->cpu_timers read/write in arm_timer() + */ + sighand = lock_task_sighand(p, &flags); + /* + * If p has just been reaped, we can no + * longer get any information about it at all. + */ + if (unlikely(sighand == NULL)) { + rcu_read_unlock(); + return -ESRCH; + } + + /* + * Disarm any old timer after extracting its expiry time. + */ + old_incr = timer->it_interval; + old_expires = cpu_timer_getexpires(ctmr); + + if (unlikely(timer->it.cpu.firing)) { + timer->it.cpu.firing = -1; + ret = TIMER_RETRY; + } else { + cpu_timer_dequeue(ctmr); + } + + /* + * 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)) + val = cpu_clock_sample(clkid, p); + else + val = cpu_clock_sample_group(clkid, p, true); + + if (old) { + if (old_expires == 0) { + old->it_value.tv_sec = 0; + old->it_value.tv_nsec = 0; + } else { + /* + * Update the timer in case it has overrun already. + * If it has, we'll report it as having overrun and + * with the next reloaded timer already ticking, + * though we are swallowing that pending + * notification here to install the new setting. + */ + u64 exp = bump_cpu_timer(timer, val); + + if (val < exp) { + old_expires = exp - val; + old->it_value = ns_to_timespec64(old_expires); + } else { + old->it_value.tv_nsec = 1; + old->it_value.tv_sec = 0; + } + } + } + + if (unlikely(ret)) { + /* + * We are colliding with the timer actually firing. + * Punt after filling in the timer's old value, and + * disable this firing since we are already reporting + * it as an overrun (thanks to bump_cpu_timer above). + */ + unlock_task_sighand(p, &flags); + goto out; + } + + if (new_expires != 0 && !(timer_flags & TIMER_ABSTIME)) { + new_expires += val; + } + + /* + * Install the new expiry time (or zero). + * For a timer with no notification action, we don't actually + * arm the timer (we'll just fake it for timer_gettime). + */ + cpu_timer_setexpires(ctmr, new_expires); + if (new_expires != 0 && val < new_expires) { + arm_timer(timer, p); + } + + unlock_task_sighand(p, &flags); + /* + * Install the new reload setting, and + * set up the signal and overrun bookkeeping. + */ + timer->it_interval = timespec64_to_ktime(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 (val >= new_expires) { + if (new_expires != 0) { + /* + * 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); + } + + /* + * Make sure we don't keep around the process wide cputime + * counter or the tick dependency if they are not necessary. + */ + sighand = lock_task_sighand(p, &flags); + if (!sighand) + goto out; + + if (!cpu_timer_queued(ctmr)) + trigger_base_recalc_expires(timer, p); + + unlock_task_sighand(p, &flags); + } + out: + rcu_read_unlock(); + if (old) + old->it_interval = ns_to_timespec64(old_incr); + + return ret; +} + +static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec64 *itp) +{ + clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock); + struct cpu_timer *ctmr = &timer->it.cpu; + u64 now, expires = cpu_timer_getexpires(ctmr); + struct task_struct *p; + + rcu_read_lock(); + p = cpu_timer_task_rcu(timer); + if (!p) + goto out; + + /* + * Easy part: convert the reload time. + */ + itp->it_interval = ktime_to_timespec64(timer->it_interval); + + if (!expires) + goto out; + + /* + * Sample the clock to take the difference with the expiry time. + */ + if (CPUCLOCK_PERTHREAD(timer->it_clock)) + now = cpu_clock_sample(clkid, p); + else + now = cpu_clock_sample_group(clkid, p, false); + + if (now < expires) { + itp->it_value = ns_to_timespec64(expires - now); + } 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; + } +out: + rcu_read_unlock(); +} + +#define MAX_COLLECTED 20 + +static u64 collect_timerqueue(struct timerqueue_head *head, + struct list_head *firing, u64 now) +{ + struct timerqueue_node *next; + int i = 0; + + while ((next = timerqueue_getnext(head))) { + struct cpu_timer *ctmr; + u64 expires; + + ctmr = container_of(next, struct cpu_timer, node); + expires = cpu_timer_getexpires(ctmr); + /* Limit the number of timers to expire at once */ + if (++i == MAX_COLLECTED || now < expires) + return expires; + + ctmr->firing = 1; + /* See posix_cpu_timer_wait_running() */ + rcu_assign_pointer(ctmr->handling, current); + cpu_timer_dequeue(ctmr); + list_add_tail(&ctmr->elist, firing); + } + + return U64_MAX; +} + +static void collect_posix_cputimers(struct posix_cputimers *pct, u64 *samples, + struct list_head *firing) +{ + struct posix_cputimer_base *base = pct->bases; + int i; + + for (i = 0; i < CPUCLOCK_MAX; i++, base++) { + base->nextevt = collect_timerqueue(&base->tqhead, firing, + samples[i]); + } +} + +static inline void check_dl_overrun(struct task_struct *tsk) +{ + if (tsk->dl.dl_overrun) { + tsk->dl.dl_overrun = 0; + send_signal_locked(SIGXCPU, SEND_SIG_PRIV, tsk, PIDTYPE_TGID); + } +} + +static bool check_rlimit(u64 time, u64 limit, int signo, bool rt, bool hard) +{ + if (time < limit) + return false; + + if (print_fatal_signals) { + pr_info("%s Watchdog Timeout (%s): %s[%d]\n", + rt ? "RT" : "CPU", hard ? "hard" : "soft", + current->comm, task_pid_nr(current)); + } + send_signal_locked(signo, SEND_SIG_PRIV, current, PIDTYPE_TGID); + return true; +} + +/* + * 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 posix_cputimers *pct = &tsk->posix_cputimers; + u64 samples[CPUCLOCK_MAX]; + unsigned long soft; + + if (dl_task(tsk)) + check_dl_overrun(tsk); + + if (expiry_cache_is_inactive(pct)) + return; + + task_sample_cputime(tsk, samples); + collect_posix_cputimers(pct, samples, firing); + + /* + * Check for the special case thread timers. + */ + soft = task_rlimit(tsk, RLIMIT_RTTIME); + if (soft != RLIM_INFINITY) { + /* Task RT timeout is accounted in jiffies. RTTIME is usec */ + unsigned long rttime = tsk->rt.timeout * (USEC_PER_SEC / HZ); + unsigned long hard = task_rlimit_max(tsk, RLIMIT_RTTIME); + + /* At the hard limit, send SIGKILL. No further action. */ + if (hard != RLIM_INFINITY && + check_rlimit(rttime, hard, SIGKILL, true, true)) + return; + + /* At the soft limit, send a SIGXCPU every second */ + if (check_rlimit(rttime, soft, SIGXCPU, true, false)) { + soft += USEC_PER_SEC; + tsk->signal->rlim[RLIMIT_RTTIME].rlim_cur = soft; + } + } + + if (expiry_cache_is_inactive(pct)) + tick_dep_clear_task(tsk, TICK_DEP_BIT_POSIX_TIMER); +} + +static inline void stop_process_timers(struct signal_struct *sig) +{ + struct posix_cputimers *pct = &sig->posix_cputimers; + + /* Turn off the active flag. This is done without locking. */ + WRITE_ONCE(pct->timers_active, false); + tick_dep_clear_signal(sig, TICK_DEP_BIT_POSIX_TIMER); +} + +static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, + u64 *expires, u64 cur_time, int signo) +{ + if (!it->expires) + return; + + if (cur_time >= it->expires) { + if (it->incr) + it->expires += it->incr; + else + it->expires = 0; + + trace_itimer_expire(signo == SIGPROF ? + ITIMER_PROF : ITIMER_VIRTUAL, + task_tgid(tsk), cur_time); + send_signal_locked(signo, SEND_SIG_PRIV, tsk, PIDTYPE_TGID); + } + + if (it->expires && it->expires < *expires) + *expires = it->expires; +} + +/* + * Check for any per-thread CPU timers that have fired and move them + * off the tsk->*_timers list onto the firing list. Per-thread timers + * have already been taken off. + */ +static void check_process_timers(struct task_struct *tsk, + struct list_head *firing) +{ + struct signal_struct *const sig = tsk->signal; + struct posix_cputimers *pct = &sig->posix_cputimers; + u64 samples[CPUCLOCK_MAX]; + unsigned long soft; + + /* + * If there are no active process wide timers (POSIX 1.b, itimers, + * RLIMIT_CPU) nothing to check. Also skip the process wide timer + * processing when there is already another task handling them. + */ + if (!READ_ONCE(pct->timers_active) || pct->expiry_active) + return; + + /* + * Signify that a thread is checking for process timers. + * Write access to this field is protected by the sighand lock. + */ + pct->expiry_active = true; + + /* + * Collect the current process totals. Group accounting is active + * so the sample can be taken directly. + */ + proc_sample_cputime_atomic(&sig->cputimer.cputime_atomic, samples); + collect_posix_cputimers(pct, samples, firing); + + /* + * Check for the special case process timers. + */ + check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], + &pct->bases[CPUCLOCK_PROF].nextevt, + samples[CPUCLOCK_PROF], SIGPROF); + check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], + &pct->bases[CPUCLOCK_VIRT].nextevt, + samples[CPUCLOCK_VIRT], SIGVTALRM); + + soft = task_rlimit(tsk, RLIMIT_CPU); + if (soft != RLIM_INFINITY) { + /* RLIMIT_CPU is in seconds. Samples are nanoseconds */ + unsigned long hard = task_rlimit_max(tsk, RLIMIT_CPU); + u64 ptime = samples[CPUCLOCK_PROF]; + u64 softns = (u64)soft * NSEC_PER_SEC; + u64 hardns = (u64)hard * NSEC_PER_SEC; + + /* At the hard limit, send SIGKILL. No further action. */ + if (hard != RLIM_INFINITY && + check_rlimit(ptime, hardns, SIGKILL, false, true)) + return; + + /* At the soft limit, send a SIGXCPU every second */ + if (check_rlimit(ptime, softns, SIGXCPU, false, false)) { + sig->rlim[RLIMIT_CPU].rlim_cur = soft + 1; + softns += NSEC_PER_SEC; + } + + /* Update the expiry cache */ + if (softns < pct->bases[CPUCLOCK_PROF].nextevt) + pct->bases[CPUCLOCK_PROF].nextevt = softns; + } + + if (expiry_cache_is_inactive(pct)) + stop_process_timers(sig); + + pct->expiry_active = false; +} + +/* + * This is called from the signal code (via posixtimer_rearm) + * when the last timer signal was delivered and we have to reload the timer. + */ +static void posix_cpu_timer_rearm(struct k_itimer *timer) +{ + clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock); + struct task_struct *p; + struct sighand_struct *sighand; + unsigned long flags; + u64 now; + + rcu_read_lock(); + p = cpu_timer_task_rcu(timer); + if (!p) + goto out; + + /* Protect timer list r/w in arm_timer() */ + sighand = lock_task_sighand(p, &flags); + if (unlikely(sighand == NULL)) + goto out; + + /* + * Fetch the current sample and update the timer's expiry time. + */ + if (CPUCLOCK_PERTHREAD(timer->it_clock)) + now = cpu_clock_sample(clkid, p); + else + now = cpu_clock_sample_group(clkid, p, true); + + bump_cpu_timer(timer, now); + + /* + * Now re-arm for the new expiry time. + */ + arm_timer(timer, p); + unlock_task_sighand(p, &flags); +out: + rcu_read_unlock(); +} + +/** + * task_cputimers_expired - Check whether posix CPU timers are expired + * + * @samples: Array of current samples for the CPUCLOCK clocks + * @pct: Pointer to a posix_cputimers container + * + * Returns true if any member of @samples is greater than the corresponding + * member of @pct->bases[CLK].nextevt. False otherwise + */ +static inline bool +task_cputimers_expired(const u64 *samples, struct posix_cputimers *pct) +{ + int i; + + for (i = 0; i < CPUCLOCK_MAX; i++) { + if (samples[i] >= pct->bases[i].nextevt) + return true; + } + return false; +} + +/** + * fastpath_timer_check - POSIX CPU timers fast path. + * + * @tsk: The task (thread) being checked. + * + * Check the task and thread group timers. If both are zero (there are no + * timers set) return false. Otherwise snapshot the task and thread group + * timers and compare them with the corresponding expiration times. Return + * true if a timer has expired, else return false. + */ +static inline bool fastpath_timer_check(struct task_struct *tsk) +{ + struct posix_cputimers *pct = &tsk->posix_cputimers; + struct signal_struct *sig; + + if (!expiry_cache_is_inactive(pct)) { + u64 samples[CPUCLOCK_MAX]; + + task_sample_cputime(tsk, samples); + if (task_cputimers_expired(samples, pct)) + return true; + } + + sig = tsk->signal; + pct = &sig->posix_cputimers; + /* + * Check if thread group timers expired when timers are active and + * no other thread in the group is already handling expiry for + * thread group cputimers. These fields are read without the + * sighand lock. However, this is fine because this is meant to be + * a fastpath heuristic to determine whether we should try to + * acquire the sighand lock to handle timer expiry. + * + * In the worst case scenario, if concurrently timers_active is set + * or expiry_active is cleared, but the current thread doesn't see + * the change yet, the timer checks are delayed until the next + * thread in the group gets a scheduler interrupt to handle the + * timer. This isn't an issue in practice because these types of + * delays with signals actually getting sent are expected. + */ + if (READ_ONCE(pct->timers_active) && !READ_ONCE(pct->expiry_active)) { + u64 samples[CPUCLOCK_MAX]; + + proc_sample_cputime_atomic(&sig->cputimer.cputime_atomic, + samples); + + if (task_cputimers_expired(samples, pct)) + return true; + } + + if (dl_task(tsk) && tsk->dl.dl_overrun) + return true; + + return false; +} + +static void handle_posix_cpu_timers(struct task_struct *tsk); + +#ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK +static void posix_cpu_timers_work(struct callback_head *work) +{ + struct posix_cputimers_work *cw = container_of(work, typeof(*cw), work); + + mutex_lock(&cw->mutex); + handle_posix_cpu_timers(current); + mutex_unlock(&cw->mutex); +} + +/* + * Invoked from the posix-timer core when a cancel operation failed because + * the timer is marked firing. The caller holds rcu_read_lock(), which + * protects the timer and the task which is expiring it from being freed. + */ +static void posix_cpu_timer_wait_running(struct k_itimer *timr) +{ + struct task_struct *tsk = rcu_dereference(timr->it.cpu.handling); + + /* Has the handling task completed expiry already? */ + if (!tsk) + return; + + /* Ensure that the task cannot go away */ + get_task_struct(tsk); + /* Now drop the RCU protection so the mutex can be locked */ + rcu_read_unlock(); + /* Wait on the expiry mutex */ + mutex_lock(&tsk->posix_cputimers_work.mutex); + /* Release it immediately again. */ + mutex_unlock(&tsk->posix_cputimers_work.mutex); + /* Drop the task reference. */ + put_task_struct(tsk); + /* Relock RCU so the callsite is balanced */ + rcu_read_lock(); +} + +static void posix_cpu_timer_wait_running_nsleep(struct k_itimer *timr) +{ + /* Ensure that timr->it.cpu.handling task cannot go away */ + rcu_read_lock(); + spin_unlock_irq(&timr->it_lock); + posix_cpu_timer_wait_running(timr); + rcu_read_unlock(); + /* @timr is on stack and is valid */ + spin_lock_irq(&timr->it_lock); +} + +/* + * Clear existing posix CPU timers task work. + */ +void clear_posix_cputimers_work(struct task_struct *p) +{ + /* + * A copied work entry from the old task is not meaningful, clear it. + * N.B. init_task_work will not do this. + */ + memset(&p->posix_cputimers_work.work, 0, + sizeof(p->posix_cputimers_work.work)); + init_task_work(&p->posix_cputimers_work.work, + posix_cpu_timers_work); + mutex_init(&p->posix_cputimers_work.mutex); + p->posix_cputimers_work.scheduled = false; +} + +/* + * Initialize posix CPU timers task work in init task. Out of line to + * keep the callback static and to avoid header recursion hell. + */ +void __init posix_cputimers_init_work(void) +{ + clear_posix_cputimers_work(current); +} + +/* + * Note: All operations on tsk->posix_cputimer_work.scheduled happen either + * in hard interrupt context or in task context with interrupts + * disabled. Aside of that the writer/reader interaction is always in the + * context of the current task, which means they are strict per CPU. + */ +static inline bool posix_cpu_timers_work_scheduled(struct task_struct *tsk) +{ + return tsk->posix_cputimers_work.scheduled; +} + +static inline void __run_posix_cpu_timers(struct task_struct *tsk) +{ + if (WARN_ON_ONCE(tsk->posix_cputimers_work.scheduled)) + return; + + /* Schedule task work to actually expire the timers */ + tsk->posix_cputimers_work.scheduled = true; + task_work_add(tsk, &tsk->posix_cputimers_work.work, TWA_RESUME); +} + +static inline bool posix_cpu_timers_enable_work(struct task_struct *tsk, + unsigned long start) +{ + bool ret = true; + + /* + * On !RT kernels interrupts are disabled while collecting expired + * timers, so no tick can happen and the fast path check can be + * reenabled without further checks. + */ + if (!IS_ENABLED(CONFIG_PREEMPT_RT)) { + tsk->posix_cputimers_work.scheduled = false; + return true; + } + + /* + * On RT enabled kernels ticks can happen while the expired timers + * are collected under sighand lock. But any tick which observes + * the CPUTIMERS_WORK_SCHEDULED bit set, does not run the fastpath + * checks. So reenabling the tick work has do be done carefully: + * + * Disable interrupts and run the fast path check if jiffies have + * advanced since the collecting of expired timers started. If + * jiffies have not advanced or the fast path check did not find + * newly expired timers, reenable the fast path check in the timer + * interrupt. If there are newly expired timers, return false and + * let the collection loop repeat. + */ + local_irq_disable(); + if (start != jiffies && fastpath_timer_check(tsk)) + ret = false; + else + tsk->posix_cputimers_work.scheduled = false; + local_irq_enable(); + + return ret; +} +#else /* CONFIG_POSIX_CPU_TIMERS_TASK_WORK */ +static inline void __run_posix_cpu_timers(struct task_struct *tsk) +{ + lockdep_posixtimer_enter(); + handle_posix_cpu_timers(tsk); + lockdep_posixtimer_exit(); +} + +static void posix_cpu_timer_wait_running(struct k_itimer *timr) +{ + cpu_relax(); +} + +static void posix_cpu_timer_wait_running_nsleep(struct k_itimer *timr) +{ + spin_unlock_irq(&timr->it_lock); + cpu_relax(); + spin_lock_irq(&timr->it_lock); +} + +static inline bool posix_cpu_timers_work_scheduled(struct task_struct *tsk) +{ + return false; +} + +static inline bool posix_cpu_timers_enable_work(struct task_struct *tsk, + unsigned long start) +{ + return true; +} +#endif /* CONFIG_POSIX_CPU_TIMERS_TASK_WORK */ + +static void handle_posix_cpu_timers(struct task_struct *tsk) +{ + struct k_itimer *timer, *next; + unsigned long flags, start; + LIST_HEAD(firing); + + if (!lock_task_sighand(tsk, &flags)) + return; + + do { + /* + * On RT locking sighand lock does not disable interrupts, + * so this needs to be careful vs. ticks. Store the current + * jiffies value. + */ + start = READ_ONCE(jiffies); + barrier(); + + /* + * Here we take off tsk->signal->cpu_timers[N] and + * tsk->cpu_timers[N] all the timers that are firing, and + * put them on the firing list. + */ + check_thread_timers(tsk, &firing); + + check_process_timers(tsk, &firing); + + /* + * The above timer checks have updated the expiry cache and + * because nothing can have queued or modified timers after + * sighand lock was taken above it is guaranteed to be + * consistent. So the next timer interrupt fastpath check + * will find valid data. + * + * If timer expiry runs in the timer interrupt context then + * the loop is not relevant as timers will be directly + * expired in interrupt context. The stub function below + * returns always true which allows the compiler to + * optimize the loop out. + * + * If timer expiry is deferred to task work context then + * the following rules apply: + * + * - On !RT kernels no tick can have happened on this CPU + * after sighand lock was acquired because interrupts are + * disabled. So reenabling task work before dropping + * sighand lock and reenabling interrupts is race free. + * + * - On RT kernels ticks might have happened but the tick + * work ignored posix CPU timer handling because the + * CPUTIMERS_WORK_SCHEDULED bit is set. Reenabling work + * must be done very carefully including a check whether + * ticks have happened since the start of the timer + * expiry checks. posix_cpu_timers_enable_work() takes + * care of that and eventually lets the expiry checks + * run again. + */ + } while (!posix_cpu_timers_enable_work(tsk, start)); + + /* + * We must release sighand lock before taking any timer's lock. + * There is a potential race with timer deletion here, as the + * siglock now protects our private firing list. We have set + * the firing flag in each timer, so that a deletion attempt + * that gets the timer lock before we do will give it up and + * spin until we've taken care of that timer below. + */ + unlock_task_sighand(tsk, &flags); + + /* + * Now that all the timers on our list have the firing flag, + * no one will touch their list entries but us. We'll take + * each timer's lock before clearing its firing flag, so no + * timer call will interfere. + */ + list_for_each_entry_safe(timer, next, &firing, it.cpu.elist) { + int cpu_firing; + + /* + * spin_lock() is sufficient here even independent of the + * expiry context. If expiry happens in hard interrupt + * context it's obvious. For task work context it's safe + * because all other operations on timer::it_lock happen in + * task context (syscall or exit). + */ + spin_lock(&timer->it_lock); + list_del_init(&timer->it.cpu.elist); + cpu_firing = timer->it.cpu.firing; + timer->it.cpu.firing = 0; + /* + * The firing flag is -1 if we collided with a reset + * of the timer, which already reported this + * almost-firing as an overrun. So don't generate an event. + */ + if (likely(cpu_firing >= 0)) + cpu_timer_fire(timer); + /* See posix_cpu_timer_wait_running() */ + rcu_assign_pointer(timer->it.cpu.handling, NULL); + spin_unlock(&timer->it_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(void) +{ + struct task_struct *tsk = current; + + lockdep_assert_irqs_disabled(); + + /* + * If the actual expiry is deferred to task work context and the + * work is already scheduled there is no point to do anything here. + */ + if (posix_cpu_timers_work_scheduled(tsk)) + return; + + /* + * The fast path checks that there are no expired thread or thread + * group timers. If that's so, just return. + */ + if (!fastpath_timer_check(tsk)) + return; + + __run_posix_cpu_timers(tsk); +} + +/* + * Set one of the process-wide special case CPU timers or RLIMIT_CPU. + * The tsk->sighand->siglock must be held by the caller. + */ +void set_process_cpu_timer(struct task_struct *tsk, unsigned int clkid, + u64 *newval, u64 *oldval) +{ + u64 now, *nextevt; + + if (WARN_ON_ONCE(clkid >= CPUCLOCK_SCHED)) + return; + + nextevt = &tsk->signal->posix_cputimers.bases[clkid].nextevt; + now = cpu_clock_sample_group(clkid, tsk, true); + + if (oldval) { + /* + * We are setting itimer. The *oldval is absolute and we update + * it to be relative, *newval argument is relative and we update + * it to be absolute. + */ + if (*oldval) { + if (*oldval <= now) { + /* Just about to fire. */ + *oldval = TICK_NSEC; + } else { + *oldval -= now; + } + } + + if (*newval) + *newval += now; + } + + /* + * Update expiration cache if this is the earliest timer. CPUCLOCK_PROF + * expiry cache is also used by RLIMIT_CPU!. + */ + if (*newval < *nextevt) + *nextevt = *newval; + + tick_dep_set_signal(tsk, TICK_DEP_BIT_POSIX_TIMER); +} + +static int do_cpu_nanosleep(const clockid_t which_clock, int flags, + const struct timespec64 *rqtp) +{ + struct itimerspec64 it; + struct k_itimer timer; + u64 expires; + int error; + + /* + * Set up a temporary timer and then wait for it to go off. + */ + memset(&timer, 0, sizeof timer); + spin_lock_init(&timer.it_lock); + timer.it_clock = which_clock; + timer.it_overrun = -1; + error = posix_cpu_timer_create(&timer); + timer.it_process = current; + + if (!error) { + static struct itimerspec64 zero_it; + struct restart_block *restart; + + memset(&it, 0, sizeof(it)); + it.it_value = *rqtp; + + spin_lock_irq(&timer.it_lock); + error = posix_cpu_timer_set(&timer, flags, &it, NULL); + if (error) { + spin_unlock_irq(&timer.it_lock); + return error; + } + + while (!signal_pending(current)) { + if (!cpu_timer_getexpires(&timer.it.cpu)) { + /* + * Our timer fired and was reset, below + * deletion can not fail. + */ + posix_cpu_timer_del(&timer); + spin_unlock_irq(&timer.it_lock); + return 0; + } + + /* + * Block until cpu_timer_fire (or a signal) wakes us. + */ + __set_current_state(TASK_INTERRUPTIBLE); + spin_unlock_irq(&timer.it_lock); + schedule(); + spin_lock_irq(&timer.it_lock); + } + + /* + * We were interrupted by a signal. + */ + expires = cpu_timer_getexpires(&timer.it.cpu); + error = posix_cpu_timer_set(&timer, 0, &zero_it, &it); + if (!error) { + /* Timer is now unarmed, deletion can not fail. */ + posix_cpu_timer_del(&timer); + } else { + while (error == TIMER_RETRY) { + posix_cpu_timer_wait_running_nsleep(&timer); + error = posix_cpu_timer_del(&timer); + } + } + + spin_unlock_irq(&timer.it_lock); + + if ((it.it_value.tv_sec | it.it_value.tv_nsec) == 0) { + /* + * It actually did fire already. + */ + return 0; + } + + error = -ERESTART_RESTARTBLOCK; + /* + * Report back to the user the time still remaining. + */ + restart = ¤t->restart_block; + restart->nanosleep.expires = expires; + if (restart->nanosleep.type != TT_NONE) + error = nanosleep_copyout(restart, &it.it_value); + } + + return error; +} + +static long posix_cpu_nsleep_restart(struct restart_block *restart_block); + +static int posix_cpu_nsleep(const clockid_t which_clock, int flags, + const struct timespec64 *rqtp) +{ + struct restart_block *restart_block = ¤t->restart_block; + int error; + + /* + * Diagnose required errors first. + */ + if (CPUCLOCK_PERTHREAD(which_clock) && + (CPUCLOCK_PID(which_clock) == 0 || + CPUCLOCK_PID(which_clock) == task_pid_vnr(current))) + return -EINVAL; + + error = do_cpu_nanosleep(which_clock, flags, rqtp); + + if (error == -ERESTART_RESTARTBLOCK) { + + if (flags & TIMER_ABSTIME) + return -ERESTARTNOHAND; + + restart_block->nanosleep.clockid = which_clock; + set_restart_fn(restart_block, posix_cpu_nsleep_restart); + } + return error; +} + +static long posix_cpu_nsleep_restart(struct restart_block *restart_block) +{ + clockid_t which_clock = restart_block->nanosleep.clockid; + struct timespec64 t; + + t = ns_to_timespec64(restart_block->nanosleep.expires); + + return do_cpu_nanosleep(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(const clockid_t which_clock, + struct timespec64 *tp) +{ + return posix_cpu_clock_getres(PROCESS_CLOCK, tp); +} +static int process_cpu_clock_get(const clockid_t which_clock, + struct timespec64 *tp) +{ + return posix_cpu_clock_get(PROCESS_CLOCK, tp); +} +static int process_cpu_timer_create(struct k_itimer *timer) +{ + timer->it_clock = PROCESS_CLOCK; + return posix_cpu_timer_create(timer); +} +static int process_cpu_nsleep(const clockid_t which_clock, int flags, + const struct timespec64 *rqtp) +{ + return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp); +} +static int thread_cpu_clock_getres(const clockid_t which_clock, + struct timespec64 *tp) +{ + return posix_cpu_clock_getres(THREAD_CLOCK, tp); +} +static int thread_cpu_clock_get(const clockid_t which_clock, + struct timespec64 *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); +} + +const struct k_clock clock_posix_cpu = { + .clock_getres = posix_cpu_clock_getres, + .clock_set = posix_cpu_clock_set, + .clock_get_timespec = posix_cpu_clock_get, + .timer_create = posix_cpu_timer_create, + .nsleep = posix_cpu_nsleep, + .timer_set = posix_cpu_timer_set, + .timer_del = posix_cpu_timer_del, + .timer_get = posix_cpu_timer_get, + .timer_rearm = posix_cpu_timer_rearm, + .timer_wait_running = posix_cpu_timer_wait_running, +}; + +const struct k_clock clock_process = { + .clock_getres = process_cpu_clock_getres, + .clock_get_timespec = process_cpu_clock_get, + .timer_create = process_cpu_timer_create, + .nsleep = process_cpu_nsleep, +}; + +const struct k_clock clock_thread = { + .clock_getres = thread_cpu_clock_getres, + .clock_get_timespec = thread_cpu_clock_get, + .timer_create = thread_cpu_timer_create, +}; |