diff --git a/fs/proc/base.c b/fs/proc/base.c index 72a1acd03675..dd579332a7f8 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2456,13 +2456,13 @@ static void *timers_start(struct seq_file *m, loff_t *pos) if (!tp->sighand) return ERR_PTR(-ESRCH); - return seq_list_start(&tp->task->signal->posix_timers, *pos); + return seq_hlist_start(&tp->task->signal->posix_timers, *pos); } static void *timers_next(struct seq_file *m, void *v, loff_t *pos) { struct timers_private *tp = m->private; - return seq_list_next(v, &tp->task->signal->posix_timers, pos); + return seq_hlist_next(v, &tp->task->signal->posix_timers, pos); } static void timers_stop(struct seq_file *m, void *v) @@ -2491,7 +2491,7 @@ static int show_timer(struct seq_file *m, void *v) [SIGEV_THREAD] = "thread", }; - timer = list_entry((struct list_head *)v, struct k_itimer, list); + timer = hlist_entry((struct hlist_node *)v, struct k_itimer, list); notify = timer->it_sigev_notify; seq_printf(m, "ID: %d\n", timer->it_id); diff --git a/fs/signalfd.c b/fs/signalfd.c index ec7b2da2477a..d0333bce015e 100644 --- a/fs/signalfd.c +++ b/fs/signalfd.c @@ -159,7 +159,7 @@ static ssize_t signalfd_dequeue(struct signalfd_ctx *ctx, kernel_siginfo_t *info DECLARE_WAITQUEUE(wait, current); spin_lock_irq(¤t->sighand->siglock); - ret = dequeue_signal(current, &ctx->sigmask, info, &type); + ret = dequeue_signal(&ctx->sigmask, info, &type); switch (ret) { case 0: if (!nonblock) @@ -174,7 +174,7 @@ static ssize_t signalfd_dequeue(struct signalfd_ctx *ctx, kernel_siginfo_t *info add_wait_queue(¤t->sighand->signalfd_wqh, &wait); for (;;) { set_current_state(TASK_INTERRUPTIBLE); - ret = dequeue_signal(current, &ctx->sigmask, info, &type); + ret = dequeue_signal(&ctx->sigmask, info, &type); if (ret != 0) break; if (signal_pending(current)) { diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h index dc7b738de299..453691710839 100644 --- a/include/linux/posix-timers.h +++ b/include/linux/posix-timers.h @@ -158,7 +158,7 @@ static inline void posix_cputimers_init_work(void) { } * @rcu: RCU head for freeing the timer. */ struct k_itimer { - struct list_head list; + struct hlist_node list; struct hlist_node t_hash; spinlock_t it_lock; const struct k_clock *kclock; diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index 0a0e23c45406..c8ed09ac29ac 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h @@ -137,7 +137,7 @@ struct signal_struct { /* POSIX.1b Interval Timers */ unsigned int next_posix_timer_id; - struct list_head posix_timers; + struct hlist_head posix_timers; /* ITIMER_REAL timer for the process */ struct hrtimer real_timer; @@ -276,8 +276,7 @@ static inline void signal_set_stop_flags(struct signal_struct *sig, extern void flush_signals(struct task_struct *); extern void ignore_signals(struct task_struct *); extern void flush_signal_handlers(struct task_struct *, int force_default); -extern int dequeue_signal(struct task_struct *task, sigset_t *mask, - kernel_siginfo_t *info, enum pid_type *type); +extern int dequeue_signal(sigset_t *mask, kernel_siginfo_t *info, enum pid_type *type); static inline int kernel_dequeue_signal(void) { @@ -287,7 +286,7 @@ static inline int kernel_dequeue_signal(void) int ret; spin_lock_irq(&task->sighand->siglock); - ret = dequeue_signal(task, &task->blocked, &__info, &__type); + ret = dequeue_signal(&task->blocked, &__info, &__type); spin_unlock_irq(&task->sighand->siglock); return ret; diff --git a/init/init_task.c b/init/init_task.c index eeb110c65fe2..5d0399bc8d2f 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -29,7 +29,7 @@ static struct signal_struct init_signals = { .cred_guard_mutex = __MUTEX_INITIALIZER(init_signals.cred_guard_mutex), .exec_update_lock = __RWSEM_INITIALIZER(init_signals.exec_update_lock), #ifdef CONFIG_POSIX_TIMERS - .posix_timers = LIST_HEAD_INIT(init_signals.posix_timers), + .posix_timers = HLIST_HEAD_INIT, .cputimer = { .cputime_atomic = INIT_CPUTIME_ATOMIC, }, diff --git a/kernel/fork.c b/kernel/fork.c index cc760491f201..c1b343cba560 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1861,7 +1861,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) prev_cputime_init(&sig->prev_cputime); #ifdef CONFIG_POSIX_TIMERS - INIT_LIST_HEAD(&sig->posix_timers); + INIT_HLIST_HEAD(&sig->posix_timers); hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); sig->real_timer.function = it_real_fn; #endif diff --git a/kernel/signal.c b/kernel/signal.c index 60c737e423a1..6f3a5aa39b09 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -618,20 +618,18 @@ static int __dequeue_signal(struct sigpending *pending, sigset_t *mask, } /* - * Dequeue a signal and return the element to the caller, which is - * expected to free it. - * - * All callers have to hold the siglock. + * Try to dequeue a signal. If a deliverable signal is found fill in the + * caller provided siginfo and return the signal number. Otherwise return + * 0. */ -int dequeue_signal(struct task_struct *tsk, sigset_t *mask, - kernel_siginfo_t *info, enum pid_type *type) +int dequeue_signal(sigset_t *mask, kernel_siginfo_t *info, enum pid_type *type) { + struct task_struct *tsk = current; bool resched_timer = false; int signr; - /* We only dequeue private signals from ourselves, we don't let - * signalfd steal them - */ + lockdep_assert_held(&tsk->sighand->siglock); + *type = PIDTYPE_PID; signr = __dequeue_signal(&tsk->pending, mask, info, &resched_timer); if (!signr) { @@ -1940,10 +1938,11 @@ struct sigqueue *sigqueue_alloc(void) void sigqueue_free(struct sigqueue *q) { - unsigned long flags; spinlock_t *lock = ¤t->sighand->siglock; + unsigned long flags; - BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); + if (WARN_ON_ONCE(!(q->flags & SIGQUEUE_PREALLOC))) + return; /* * We must hold ->siglock while testing q->list * to serialize with collect_signal() or with @@ -1971,7 +1970,10 @@ int send_sigqueue(struct sigqueue *q, struct pid *pid, enum pid_type type) unsigned long flags; int ret, result; - BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); + if (WARN_ON_ONCE(!(q->flags & SIGQUEUE_PREALLOC))) + return 0; + if (WARN_ON_ONCE(q->info.si_code != SI_TIMER)) + return 0; ret = -1; rcu_read_lock(); @@ -2006,7 +2008,6 @@ int send_sigqueue(struct sigqueue *q, struct pid *pid, enum pid_type type) * If an SI_TIMER entry is already queue just increment * the overrun count. */ - BUG_ON(q->info.si_code != SI_TIMER); q->info.si_overrun++; result = TRACE_SIGNAL_ALREADY_PENDING; goto out; @@ -2793,8 +2794,7 @@ relock: type = PIDTYPE_PID; signr = dequeue_synchronous_signal(&ksig->info); if (!signr) - signr = dequeue_signal(current, ¤t->blocked, - &ksig->info, &type); + signr = dequeue_signal(¤t->blocked, &ksig->info, &type); if (!signr) break; /* will return 0 */ @@ -3648,7 +3648,7 @@ static int do_sigtimedwait(const sigset_t *which, kernel_siginfo_t *info, signotset(&mask); spin_lock_irq(&tsk->sighand->siglock); - sig = dequeue_signal(tsk, &mask, info, &type); + sig = dequeue_signal(&mask, info, &type); if (!sig && timeout) { /* * None ready, temporarily unblock those we're interested @@ -3667,7 +3667,7 @@ static int do_sigtimedwait(const sigset_t *which, kernel_siginfo_t *info, spin_lock_irq(&tsk->sighand->siglock); __set_task_blocked(tsk, &tsk->real_blocked); sigemptyset(&tsk->real_blocked); - sig = dequeue_signal(tsk, &mask, info, &type); + sig = dequeue_signal(&mask, info, &type); } spin_unlock_irq(&tsk->sighand->siglock); diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index 5abfa4390673..76bd4fda3472 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -574,15 +574,10 @@ static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm, it.alarm.alarmtimer); enum alarmtimer_restart result = ALARMTIMER_NORESTART; unsigned long flags; - int si_private = 0; spin_lock_irqsave(&ptr->it_lock, flags); - ptr->it_active = 0; - if (ptr->it_interval) - si_private = ++ptr->it_requeue_pending; - - if (posix_timer_event(ptr, si_private) && ptr->it_interval) { + if (posix_timer_queue_signal(ptr) && ptr->it_interval) { /* * Handle ignored signals and rearm the timer. This will go * away once we handle ignored signals proper. Ensure that diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index e9c6f9d0e42c..6bcee4704059 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -453,6 +453,7 @@ static void disarm_timer(struct k_itimer *timer, struct task_struct *p) struct cpu_timer *ctmr = &timer->it.cpu; struct posix_cputimer_base *base; + timer->it_active = 0; if (!cpu_timer_dequeue(ctmr)) return; @@ -559,6 +560,7 @@ static void arm_timer(struct k_itimer *timer, struct task_struct *p) struct cpu_timer *ctmr = &timer->it.cpu; u64 newexp = cpu_timer_getexpires(ctmr); + timer->it_active = 1; if (!cpu_timer_enqueue(&base->tqhead, ctmr)) return; @@ -584,12 +586,8 @@ 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)) { + timer->it_active = 0; + if (unlikely(timer->sigq == NULL)) { /* * This a special case for clock_nanosleep, * not a normal timer from sys_timer_create. @@ -600,9 +598,9 @@ static void cpu_timer_fire(struct k_itimer *timer) /* * One-shot timer. Clear it as soon as it's fired. */ - posix_timer_event(timer, 0); + posix_timer_queue_signal(timer); cpu_timer_setexpires(ctmr, 0); - } else if (posix_timer_event(timer, ++timer->it_requeue_pending)) { + } else if (posix_timer_queue_signal(timer)) { /* * The signal did not get queued because the signal * was ignored, so we won't get any callback to @@ -614,6 +612,8 @@ static void cpu_timer_fire(struct k_itimer *timer) } } +static void __posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec64 *itp, u64 now); + /* * Guts of sys_timer_settime for CPU timers. * This is called with the timer locked and interrupts disabled. @@ -623,9 +623,10 @@ static void cpu_timer_fire(struct k_itimer *timer) static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags, struct itimerspec64 *new, struct itimerspec64 *old) { + bool sigev_none = timer->it_sigev_notify == SIGEV_NONE; clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock); - u64 old_expires, new_expires, old_incr, val; struct cpu_timer *ctmr = &timer->it.cpu; + u64 old_expires, new_expires, now; struct sighand_struct *sighand; struct task_struct *p; unsigned long flags; @@ -662,10 +663,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags, return -ESRCH; } - /* - * Disarm any old timer after extracting its expiry time. - */ - old_incr = timer->it_interval; + /* Retrieve the current expiry time before disarming the timer */ old_expires = cpu_timer_getexpires(ctmr); if (unlikely(timer->it.cpu.firing)) { @@ -673,157 +671,122 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags, ret = TIMER_RETRY; } else { cpu_timer_dequeue(ctmr); + timer->it_active = 0; } /* - * 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. + * Sample the current clock for saving the previous setting + * and for rearming the timer. */ if (CPUCLOCK_PERTHREAD(timer->it_clock)) - val = cpu_clock_sample(clkid, p); + now = cpu_clock_sample(clkid, p); else - val = cpu_clock_sample_group(clkid, p, true); + now = cpu_clock_sample_group(clkid, p, !sigev_none); + /* Retrieve the previous expiry value if requested. */ 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; - } - } + old->it_value = (struct timespec64){ }; + if (old_expires) + __posix_cpu_timer_get(timer, old, now); } + /* Retry if the timer expiry is running concurrently */ 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; - } + /* Convert relative expiry time to absolute */ + if (new_expires && !(timer_flags & TIMER_ABSTIME)) + new_expires += now; + + /* Set the new expiry time (might be 0) */ + cpu_timer_setexpires(ctmr, new_expires); /* - * 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). + * Arm the timer if it is not disabled, the new expiry value has + * not yet expired and the timer requires signal delivery. + * SIGEV_NONE timers are never armed. In case the timer is not + * armed, enforce the reevaluation of the timer base so that the + * process wide cputime counter can be disabled eventually. */ - cpu_timer_setexpires(ctmr, new_expires); - if (new_expires != 0 && val < new_expires) { - arm_timer(timer, p); + if (likely(!sigev_none)) { + if (new_expires && now < new_expires) + arm_timer(timer, p); + else + trigger_base_recalc_expires(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); + + posix_timer_set_common(timer, new); /* - * 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. + * If the new expiry time was already in the past the timer was not + * queued. Fire it immediately even if the thread never runs to + * accumulate more time on this clock. */ - 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: + if (!sigev_none && new_expires && now >= new_expires) + cpu_timer_fire(timer); +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, u64 now) +{ + bool sigev_none = timer->it_sigev_notify == SIGEV_NONE; + u64 expires, iv = timer->it_interval; + + /* + * Make sure that interval timers are moved forward for the + * following cases: + * - SIGEV_NONE timers which are never armed + * - Timers which expired, but the signal has not yet been + * delivered + */ + if (iv && ((timer->it_requeue_pending & REQUEUE_PENDING) || sigev_none)) + expires = bump_cpu_timer(timer, now); + else + expires = cpu_timer_getexpires(&timer->it.cpu); + + /* + * Expired interval timers cannot have a remaining time <= 0. + * The kernel has to move them forward so that the next + * timer expiry is > @now. + */ + if (now < expires) { + itp->it_value = ns_to_timespec64(expires - now); + } else { + /* + * 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 (!sigev_none) + itp->it_value.tv_nsec = 1; + } +} + 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; + u64 now; rcu_read_lock(); p = cpu_timer_task_rcu(timer); - if (!p) - goto out; + if (p && cpu_timer_getexpires(&timer->it.cpu)) { + itp->it_interval = ktime_to_timespec64(timer->it_interval); - /* - * Easy part: convert the reload time. - */ - itp->it_interval = ktime_to_timespec64(timer->it_interval); + if (CPUCLOCK_PERTHREAD(timer->it_clock)) + now = cpu_clock_sample(clkid, p); + else + now = cpu_clock_sample_group(clkid, p, false); - 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; + __posix_cpu_timer_get(timer, itp, now); } -out: rcu_read_unlock(); } diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c index b924f0f096fa..1cc830ef93a7 100644 --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -277,10 +277,17 @@ void posixtimer_rearm(struct kernel_siginfo *info) unlock_timer(timr, flags); } -int posix_timer_event(struct k_itimer *timr, int si_private) +int posix_timer_queue_signal(struct k_itimer *timr) { + int ret, si_private = 0; enum pid_type type; - int ret; + + lockdep_assert_held(&timr->it_lock); + + timr->it_active = 0; + if (timr->it_interval) + si_private = ++timr->it_requeue_pending; + /* * FIXME: if ->sigq is queued we can race with * dequeue_signal()->posixtimer_rearm(). @@ -309,19 +316,13 @@ int posix_timer_event(struct k_itimer *timr, int si_private) */ static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer) { + struct k_itimer *timr = container_of(timer, struct k_itimer, it.real.timer); enum hrtimer_restart ret = HRTIMER_NORESTART; - struct k_itimer *timr; unsigned long flags; - int si_private = 0; - timr = container_of(timer, struct k_itimer, it.real.timer); spin_lock_irqsave(&timr->it_lock, flags); - timr->it_active = 0; - if (timr->it_interval != 0) - si_private = ++timr->it_requeue_pending; - - if (posix_timer_event(timr, si_private)) { + if (posix_timer_queue_signal(timr)) { /* * The signal was not queued due to SIG_IGN. As a * consequence the timer is not going to be rearmed from @@ -515,7 +516,7 @@ static int do_timer_create(clockid_t which_clock, struct sigevent *event, spin_lock_irq(¤t->sighand->siglock); /* This makes the timer valid in the hash table */ WRITE_ONCE(new_timer->it_signal, current->signal); - list_add(&new_timer->list, ¤t->signal->posix_timers); + hlist_add_head(&new_timer->list, ¤t->signal->posix_timers); spin_unlock_irq(¤t->sighand->siglock); /* * After unlocking sighand::siglock @new_timer is subject to @@ -856,6 +857,23 @@ static struct k_itimer *timer_wait_running(struct k_itimer *timer, return lock_timer(timer_id, flags); } +/* + * 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; + + /* Prevent reloading in case there is a signal pending */ + timer->it_requeue_pending = (timer->it_requeue_pending + 2) & ~REQUEUE_PENDING; + /* 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, @@ -878,15 +896,12 @@ int common_timer_set(struct k_itimer *timr, int flags, return TIMER_RETRY; timr->it_active = 0; - timr->it_requeue_pending = (timr->it_requeue_pending + 2) & - ~REQUEUE_PENDING; - timr->it_overrun_last = 0; + posix_timer_set_common(timr, new_setting); - /* Switch off the timer when it_value is zero */ + /* Keep timer disarmed when it_value is zero */ if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec) return 0; - timr->it_interval = timespec64_to_ktime(new_setting->it_interval); expires = timespec64_to_ktime(new_setting->it_value); if (flags & TIMER_ABSTIME) expires = timens_ktime_to_host(timr->it_clock, expires); @@ -904,7 +919,7 @@ static int do_timer_settime(timer_t timer_id, int tmr_flags, const struct k_clock *kc; struct k_itimer *timr; unsigned long flags; - int error = 0; + int error; if (!timespec64_valid(&new_spec64->it_interval) || !timespec64_valid(&new_spec64->it_value)) @@ -918,6 +933,9 @@ retry: if (!timr) return -EINVAL; + if (old_spec64) + old_spec64->it_interval = ktime_to_timespec64(timr->it_interval); + kc = timr->kclock; if (WARN_ON_ONCE(!kc || !kc->timer_set)) error = -EINVAL; @@ -1021,7 +1039,7 @@ retry_delete: } spin_lock(¤t->sighand->siglock); - list_del(&timer->list); + hlist_del(&timer->list); spin_unlock(¤t->sighand->siglock); /* * A concurrent lookup could check timer::it_signal lockless. It @@ -1071,7 +1089,7 @@ retry_delete: goto retry_delete; } - list_del(&timer->list); + hlist_del(&timer->list); /* * Setting timer::it_signal to NULL is technically not required @@ -1092,22 +1110,19 @@ retry_delete: */ void exit_itimers(struct task_struct *tsk) { - struct list_head timers; - struct k_itimer *tmr; + struct hlist_head timers; - if (list_empty(&tsk->signal->posix_timers)) + if (hlist_empty(&tsk->signal->posix_timers)) return; /* Protect against concurrent read via /proc/$PID/timers */ spin_lock_irq(&tsk->sighand->siglock); - list_replace_init(&tsk->signal->posix_timers, &timers); + hlist_move_list(&tsk->signal->posix_timers, &timers); spin_unlock_irq(&tsk->sighand->siglock); /* The timers are not longer accessible via tsk::signal */ - while (!list_empty(&timers)) { - tmr = list_first_entry(&timers, struct k_itimer, list); - itimer_delete(tmr); - } + while (!hlist_empty(&timers)) + itimer_delete(hlist_entry(timers.first, struct k_itimer, list)); } SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock, diff --git a/kernel/time/posix-timers.h b/kernel/time/posix-timers.h index f32a2ebba9b8..4784ea65f685 100644 --- a/kernel/time/posix-timers.h +++ b/kernel/time/posix-timers.h @@ -36,10 +36,11 @@ extern const struct k_clock clock_process; extern const struct k_clock clock_thread; extern const struct k_clock alarm_clock; -int posix_timer_event(struct k_itimer *timr, int si_private); +int posix_timer_queue_signal(struct k_itimer *timr); void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting); int common_timer_set(struct k_itimer *timr, int flags, struct itimerspec64 *new_setting, struct itimerspec64 *old_setting); +void posix_timer_set_common(struct k_itimer *timer, struct itimerspec64 *new_setting); int common_timer_del(struct k_itimer *timer); diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c index 07c81c0093c0..16bd49492efa 100644 --- a/tools/testing/selftests/timers/posix_timers.c +++ b/tools/testing/selftests/timers/posix_timers.c @@ -6,10 +6,13 @@ * * Kernel loop code stolen from Steven Rostedt */ - +#define _GNU_SOURCE #include +#include #include #include +#include +#include #include #include #include @@ -18,6 +21,21 @@ #define DELAY 2 #define USECS_PER_SEC 1000000 +#define NSECS_PER_SEC 1000000000 + +static void __fatal_error(const char *test, const char *name, const char *what) +{ + char buf[64]; + + strerror_r(errno, buf, sizeof(buf)); + + if (name && strlen(name)) + ksft_exit_fail_msg("%s %s %s %s\n", test, name, what, buf); + else + ksft_exit_fail_msg("%s %s %s\n", test, what, buf); +} + +#define fatal_error(name, what) __fatal_error(__func__, name, what) static volatile int done; @@ -74,24 +92,13 @@ static int check_diff(struct timeval start, struct timeval end) return 0; } -static int check_itimer(int which) +static void check_itimer(int which, const char *name) { - const char *name; - int err; struct timeval start, end; struct itimerval val = { .it_value.tv_sec = DELAY, }; - if (which == ITIMER_VIRTUAL) - name = "ITIMER_VIRTUAL"; - else if (which == ITIMER_PROF) - name = "ITIMER_PROF"; - else if (which == ITIMER_REAL) - name = "ITIMER_REAL"; - else - return -1; - done = 0; if (which == ITIMER_VIRTUAL) @@ -101,17 +108,11 @@ static int check_itimer(int which) else if (which == ITIMER_REAL) signal(SIGALRM, sig_handler); - err = gettimeofday(&start, NULL); - if (err < 0) { - ksft_perror("Can't call gettimeofday()"); - return -1; - } + if (gettimeofday(&start, NULL) < 0) + fatal_error(name, "gettimeofday()"); - err = setitimer(which, &val, NULL); - if (err < 0) { - ksft_perror("Can't set timer"); - return -1; - } + if (setitimer(which, &val, NULL) < 0) + fatal_error(name, "setitimer()"); if (which == ITIMER_VIRTUAL) user_loop(); @@ -120,68 +121,41 @@ static int check_itimer(int which) else if (which == ITIMER_REAL) idle_loop(); - err = gettimeofday(&end, NULL); - if (err < 0) { - ksft_perror("Can't call gettimeofday()"); - return -1; - } + if (gettimeofday(&end, NULL) < 0) + fatal_error(name, "gettimeofday()"); ksft_test_result(check_diff(start, end) == 0, "%s\n", name); - - return 0; } -static int check_timer_create(int which) +static void check_timer_create(int which, const char *name) { - const char *type; - int err; - timer_t id; struct timeval start, end; struct itimerspec val = { .it_value.tv_sec = DELAY, }; - - if (which == CLOCK_THREAD_CPUTIME_ID) { - type = "thread"; - } else if (which == CLOCK_PROCESS_CPUTIME_ID) { - type = "process"; - } else { - ksft_print_msg("Unknown timer_create() type %d\n", which); - return -1; - } + timer_t id; done = 0; - err = timer_create(which, NULL, &id); - if (err < 0) { - ksft_perror("Can't create timer"); - return -1; - } - signal(SIGALRM, sig_handler); - err = gettimeofday(&start, NULL); - if (err < 0) { - ksft_perror("Can't call gettimeofday()"); - return -1; - } + if (timer_create(which, NULL, &id) < 0) + fatal_error(name, "timer_create()"); - err = timer_settime(id, 0, &val, NULL); - if (err < 0) { - ksft_perror("Can't set timer"); - return -1; - } + if (signal(SIGALRM, sig_handler) == SIG_ERR) + fatal_error(name, "signal()"); + + if (gettimeofday(&start, NULL) < 0) + fatal_error(name, "gettimeofday()"); + + if (timer_settime(id, 0, &val, NULL) < 0) + fatal_error(name, "timer_settime()"); user_loop(); - err = gettimeofday(&end, NULL); - if (err < 0) { - ksft_perror("Can't call gettimeofday()"); - return -1; - } + if (gettimeofday(&end, NULL) < 0) + fatal_error(name, "gettimeofday()"); ksft_test_result(check_diff(start, end) == 0, - "timer_create() per %s\n", type); - - return 0; + "timer_create() per %s\n", name); } static pthread_t ctd_thread; @@ -209,15 +183,14 @@ static void *ctd_thread_func(void *arg) ctd_count = 100; if (timer_create(CLOCK_PROCESS_CPUTIME_ID, NULL, &id)) - return "Can't create timer\n"; + fatal_error(NULL, "timer_create()"); if (timer_settime(id, 0, &val, NULL)) - return "Can't set timer\n"; - + fatal_error(NULL, "timer_settime()"); while (ctd_count > 0 && !ctd_failed) ; if (timer_delete(id)) - return "Can't delete timer\n"; + fatal_error(NULL, "timer_delete()"); return NULL; } @@ -225,19 +198,16 @@ static void *ctd_thread_func(void *arg) /* * Test that only the running thread receives the timer signal. */ -static int check_timer_distribution(void) +static void check_timer_distribution(void) { - const char *errmsg; + if (signal(SIGALRM, ctd_sighandler) == SIG_ERR) + fatal_error(NULL, "signal()"); - signal(SIGALRM, ctd_sighandler); - - errmsg = "Can't create thread\n"; if (pthread_create(&ctd_thread, NULL, ctd_thread_func, NULL)) - goto err; + fatal_error(NULL, "pthread_create()"); - errmsg = "Can't join thread\n"; - if (pthread_join(ctd_thread, (void **)&errmsg) || errmsg) - goto err; + if (pthread_join(ctd_thread, NULL)) + fatal_error(NULL, "pthread_join()"); if (!ctd_failed) ksft_test_result_pass("check signal distribution\n"); @@ -245,31 +215,399 @@ static int check_timer_distribution(void) ksft_test_result_fail("check signal distribution\n"); else ksft_test_result_skip("check signal distribution (old kernel)\n"); - return 0; -err: - ksft_print_msg("%s", errmsg); - return -1; +} + +struct tmrsig { + int signals; + int overruns; +}; + +static void siginfo_handler(int sig, siginfo_t *si, void *uc) +{ + struct tmrsig *tsig = si ? si->si_ptr : NULL; + + if (tsig) { + tsig->signals++; + tsig->overruns += si->si_overrun; + } +} + +static void *ignore_thread(void *arg) +{ + unsigned int *tid = arg; + sigset_t set; + + sigemptyset(&set); + sigaddset(&set, SIGUSR1); + if (sigprocmask(SIG_BLOCK, &set, NULL)) + fatal_error(NULL, "sigprocmask(SIG_BLOCK)"); + + *tid = gettid(); + sleep(100); + + if (sigprocmask(SIG_UNBLOCK, &set, NULL)) + fatal_error(NULL, "sigprocmask(SIG_UNBLOCK)"); + return NULL; +} + +static void check_sig_ign(int thread) +{ + struct tmrsig tsig = { }; + struct itimerspec its; + unsigned int tid = 0; + struct sigaction sa; + struct sigevent sev; + pthread_t pthread; + timer_t timerid; + sigset_t set; + + if (thread) { + if (pthread_create(&pthread, NULL, ignore_thread, &tid)) + fatal_error(NULL, "pthread_create()"); + sleep(1); + } + + sa.sa_flags = SA_SIGINFO; + sa.sa_sigaction = siginfo_handler; + sigemptyset(&sa.sa_mask); + if (sigaction(SIGUSR1, &sa, NULL)) + fatal_error(NULL, "sigaction()"); + + /* Block the signal */ + sigemptyset(&set); + sigaddset(&set, SIGUSR1); + if (sigprocmask(SIG_BLOCK, &set, NULL)) + fatal_error(NULL, "sigprocmask(SIG_BLOCK)"); + + memset(&sev, 0, sizeof(sev)); + sev.sigev_notify = SIGEV_SIGNAL; + sev.sigev_signo = SIGUSR1; + sev.sigev_value.sival_ptr = &tsig; + if (thread) { + sev.sigev_notify = SIGEV_THREAD_ID; + sev._sigev_un._tid = tid; + } + + if (timer_create(CLOCK_MONOTONIC, &sev, &timerid)) + fatal_error(NULL, "timer_create()"); + + /* Start the timer to expire in 100ms and 100ms intervals */ + its.it_value.tv_sec = 0; + its.it_value.tv_nsec = 100000000; + its.it_interval.tv_sec = 0; + its.it_interval.tv_nsec = 100000000; + timer_settime(timerid, 0, &its, NULL); + + sleep(1); + + /* Set the signal to be ignored */ + if (signal(SIGUSR1, SIG_IGN) == SIG_ERR) + fatal_error(NULL, "signal(SIG_IGN)"); + + sleep(1); + + if (thread) { + /* Stop the thread first. No signal should be delivered to it */ + if (pthread_cancel(pthread)) + fatal_error(NULL, "pthread_cancel()"); + if (pthread_join(pthread, NULL)) + fatal_error(NULL, "pthread_join()"); + } + + /* Restore the handler */ + if (sigaction(SIGUSR1, &sa, NULL)) + fatal_error(NULL, "sigaction()"); + + sleep(1); + + /* Unblock it, which should deliver the signal in the !thread case*/ + if (sigprocmask(SIG_UNBLOCK, &set, NULL)) + fatal_error(NULL, "sigprocmask(SIG_UNBLOCK)"); + + if (timer_delete(timerid)) + fatal_error(NULL, "timer_delete()"); + + if (!thread) { + ksft_test_result(tsig.signals == 1 && tsig.overruns == 29, + "check_sig_ign SIGEV_SIGNAL\n"); + } else { + ksft_test_result(tsig.signals == 0 && tsig.overruns == 0, + "check_sig_ign SIGEV_THREAD_ID\n"); + } +} + +static void check_rearm(void) +{ + struct tmrsig tsig = { }; + struct itimerspec its; + struct sigaction sa; + struct sigevent sev; + timer_t timerid; + sigset_t set; + + sa.sa_flags = SA_SIGINFO; + sa.sa_sigaction = siginfo_handler; + sigemptyset(&sa.sa_mask); + if (sigaction(SIGUSR1, &sa, NULL)) + fatal_error(NULL, "sigaction()"); + + /* Block the signal */ + sigemptyset(&set); + sigaddset(&set, SIGUSR1); + if (sigprocmask(SIG_BLOCK, &set, NULL)) + fatal_error(NULL, "sigprocmask(SIG_BLOCK)"); + + memset(&sev, 0, sizeof(sev)); + sev.sigev_notify = SIGEV_SIGNAL; + sev.sigev_signo = SIGUSR1; + sev.sigev_value.sival_ptr = &tsig; + if (timer_create(CLOCK_MONOTONIC, &sev, &timerid)) + fatal_error(NULL, "timer_create()"); + + /* Start the timer to expire in 100ms and 100ms intervals */ + its.it_value.tv_sec = 0; + its.it_value.tv_nsec = 100000000; + its.it_interval.tv_sec = 0; + its.it_interval.tv_nsec = 100000000; + if (timer_settime(timerid, 0, &its, NULL)) + fatal_error(NULL, "timer_settime()"); + + sleep(1); + + /* Reprogram the timer to single shot */ + its.it_value.tv_sec = 10; + its.it_value.tv_nsec = 0; + its.it_interval.tv_sec = 0; + its.it_interval.tv_nsec = 0; + if (timer_settime(timerid, 0, &its, NULL)) + fatal_error(NULL, "timer_settime()"); + + /* Unblock it, which should not deliver a signal */ + if (sigprocmask(SIG_UNBLOCK, &set, NULL)) + fatal_error(NULL, "sigprocmask(SIG_UNBLOCK)"); + + if (timer_delete(timerid)) + fatal_error(NULL, "timer_delete()"); + + ksft_test_result(!tsig.signals, "check_rearm\n"); +} + +static void check_delete(void) +{ + struct tmrsig tsig = { }; + struct itimerspec its; + struct sigaction sa; + struct sigevent sev; + timer_t timerid; + sigset_t set; + + sa.sa_flags = SA_SIGINFO; + sa.sa_sigaction = siginfo_handler; + sigemptyset(&sa.sa_mask); + if (sigaction(SIGUSR1, &sa, NULL)) + fatal_error(NULL, "sigaction()"); + + /* Block the signal */ + sigemptyset(&set); + sigaddset(&set, SIGUSR1); + if (sigprocmask(SIG_BLOCK, &set, NULL)) + fatal_error(NULL, "sigprocmask(SIG_BLOCK)"); + + memset(&sev, 0, sizeof(sev)); + sev.sigev_notify = SIGEV_SIGNAL; + sev.sigev_signo = SIGUSR1; + sev.sigev_value.sival_ptr = &tsig; + if (timer_create(CLOCK_MONOTONIC, &sev, &timerid)) + fatal_error(NULL, "timer_create()"); + + /* Start the timer to expire in 100ms and 100ms intervals */ + its.it_value.tv_sec = 0; + its.it_value.tv_nsec = 100000000; + its.it_interval.tv_sec = 0; + its.it_interval.tv_nsec = 100000000; + if (timer_settime(timerid, 0, &its, NULL)) + fatal_error(NULL, "timer_settime()"); + + sleep(1); + + if (timer_delete(timerid)) + fatal_error(NULL, "timer_delete()"); + + /* Unblock it, which should not deliver a signal */ + if (sigprocmask(SIG_UNBLOCK, &set, NULL)) + fatal_error(NULL, "sigprocmask(SIG_UNBLOCK)"); + + ksft_test_result(!tsig.signals, "check_delete\n"); +} + +static inline int64_t calcdiff_ns(struct timespec t1, struct timespec t2) +{ + int64_t diff; + + diff = NSECS_PER_SEC * (int64_t)((int) t1.tv_sec - (int) t2.tv_sec); + diff += ((int) t1.tv_nsec - (int) t2.tv_nsec); + return diff; +} + +static void check_sigev_none(int which, const char *name) +{ + struct timespec start, now; + struct itimerspec its; + struct sigevent sev; + timer_t timerid; + + memset(&sev, 0, sizeof(sev)); + sev.sigev_notify = SIGEV_NONE; + + if (timer_create(which, &sev, &timerid)) + fatal_error(name, "timer_create()"); + + /* Start the timer to expire in 100ms and 100ms intervals */ + its.it_value.tv_sec = 0; + its.it_value.tv_nsec = 100000000; + its.it_interval.tv_sec = 0; + its.it_interval.tv_nsec = 100000000; + timer_settime(timerid, 0, &its, NULL); + + if (clock_gettime(which, &start)) + fatal_error(name, "clock_gettime()"); + + do { + if (clock_gettime(which, &now)) + fatal_error(name, "clock_gettime()"); + } while (calcdiff_ns(now, start) < NSECS_PER_SEC); + + if (timer_gettime(timerid, &its)) + fatal_error(name, "timer_gettime()"); + + if (timer_delete(timerid)) + fatal_error(name, "timer_delete()"); + + ksft_test_result(its.it_value.tv_sec || its.it_value.tv_nsec, + "check_sigev_none %s\n", name); +} + +static void check_gettime(int which, const char *name) +{ + struct itimerspec its, prev; + struct timespec start, now; + struct sigevent sev; + timer_t timerid; + int wraps = 0; + sigset_t set; + + /* Block the signal */ + sigemptyset(&set); + sigaddset(&set, SIGUSR1); + if (sigprocmask(SIG_BLOCK, &set, NULL)) + fatal_error(name, "sigprocmask(SIG_BLOCK)"); + + memset(&sev, 0, sizeof(sev)); + sev.sigev_notify = SIGEV_SIGNAL; + sev.sigev_signo = SIGUSR1; + + if (timer_create(which, &sev, &timerid)) + fatal_error(name, "timer_create()"); + + /* Start the timer to expire in 100ms and 100ms intervals */ + its.it_value.tv_sec = 0; + its.it_value.tv_nsec = 100000000; + its.it_interval.tv_sec = 0; + its.it_interval.tv_nsec = 100000000; + if (timer_settime(timerid, 0, &its, NULL)) + fatal_error(name, "timer_settime()"); + + if (timer_gettime(timerid, &prev)) + fatal_error(name, "timer_gettime()"); + + if (clock_gettime(which, &start)) + fatal_error(name, "clock_gettime()"); + + do { + if (clock_gettime(which, &now)) + fatal_error(name, "clock_gettime()"); + if (timer_gettime(timerid, &its)) + fatal_error(name, "timer_gettime()"); + if (its.it_value.tv_nsec > prev.it_value.tv_nsec) + wraps++; + prev = its; + + } while (calcdiff_ns(now, start) < NSECS_PER_SEC); + + if (timer_delete(timerid)) + fatal_error(name, "timer_delete()"); + + ksft_test_result(wraps > 1, "check_gettime %s\n", name); +} + +static void check_overrun(int which, const char *name) +{ + struct timespec start, now; + struct tmrsig tsig = { }; + struct itimerspec its; + struct sigaction sa; + struct sigevent sev; + timer_t timerid; + sigset_t set; + + sa.sa_flags = SA_SIGINFO; + sa.sa_sigaction = siginfo_handler; + sigemptyset(&sa.sa_mask); + if (sigaction(SIGUSR1, &sa, NULL)) + fatal_error(name, "sigaction()"); + + /* Block the signal */ + sigemptyset(&set); + sigaddset(&set, SIGUSR1); + if (sigprocmask(SIG_BLOCK, &set, NULL)) + fatal_error(name, "sigprocmask(SIG_BLOCK)"); + + memset(&sev, 0, sizeof(sev)); + sev.sigev_notify = SIGEV_SIGNAL; + sev.sigev_signo = SIGUSR1; + sev.sigev_value.sival_ptr = &tsig; + if (timer_create(which, &sev, &timerid)) + fatal_error(name, "timer_create()"); + + /* Start the timer to expire in 100ms and 100ms intervals */ + its.it_value.tv_sec = 0; + its.it_value.tv_nsec = 100000000; + its.it_interval.tv_sec = 0; + its.it_interval.tv_nsec = 100000000; + if (timer_settime(timerid, 0, &its, NULL)) + fatal_error(name, "timer_settime()"); + + if (clock_gettime(which, &start)) + fatal_error(name, "clock_gettime()"); + + do { + if (clock_gettime(which, &now)) + fatal_error(name, "clock_gettime()"); + } while (calcdiff_ns(now, start) < NSECS_PER_SEC); + + /* Unblock it, which should deliver a signal */ + if (sigprocmask(SIG_UNBLOCK, &set, NULL)) + fatal_error(name, "sigprocmask(SIG_UNBLOCK)"); + + if (timer_delete(timerid)) + fatal_error(name, "timer_delete()"); + + ksft_test_result(tsig.signals == 1 && tsig.overruns == 9, + "check_overrun %s\n", name); } int main(int argc, char **argv) { ksft_print_header(); - ksft_set_plan(6); + ksft_set_plan(18); ksft_print_msg("Testing posix timers. False negative may happen on CPU execution \n"); ksft_print_msg("based timers if other threads run on the CPU...\n"); - if (check_itimer(ITIMER_VIRTUAL) < 0) - ksft_exit_fail(); - - if (check_itimer(ITIMER_PROF) < 0) - ksft_exit_fail(); - - if (check_itimer(ITIMER_REAL) < 0) - ksft_exit_fail(); - - if (check_timer_create(CLOCK_THREAD_CPUTIME_ID) < 0) - ksft_exit_fail(); + check_itimer(ITIMER_VIRTUAL, "ITIMER_VIRTUAL"); + check_itimer(ITIMER_PROF, "ITIMER_PROF"); + check_itimer(ITIMER_REAL, "ITIMER_REAL"); + check_timer_create(CLOCK_THREAD_CPUTIME_ID, "CLOCK_THREAD_CPUTIME_ID"); /* * It's unfortunately hard to reliably test a timer expiration @@ -280,11 +618,21 @@ int main(int argc, char **argv) * to ensure true parallelism. So test only one thread until we * find a better solution. */ - if (check_timer_create(CLOCK_PROCESS_CPUTIME_ID) < 0) - ksft_exit_fail(); + check_timer_create(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID"); + check_timer_distribution(); - if (check_timer_distribution() < 0) - ksft_exit_fail(); + check_sig_ign(0); + check_sig_ign(1); + check_rearm(); + check_delete(); + check_sigev_none(CLOCK_MONOTONIC, "CLOCK_MONOTONIC"); + check_sigev_none(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID"); + check_gettime(CLOCK_MONOTONIC, "CLOCK_MONOTONIC"); + check_gettime(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID"); + check_gettime(CLOCK_THREAD_CPUTIME_ID, "CLOCK_THREAD_CPUTIME_ID"); + check_overrun(CLOCK_MONOTONIC, "CLOCK_MONOTONIC"); + check_overrun(CLOCK_PROCESS_CPUTIME_ID, "CLOCK_PROCESS_CPUTIME_ID"); + check_overrun(CLOCK_THREAD_CPUTIME_ID, "CLOCK_THREAD_CPUTIME_ID"); ksft_finished(); }