diff options
Diffstat (limited to 'kernel/time/alarmtimer.c')
-rw-r--r-- | kernel/time/alarmtimer.c | 381 |
1 files changed, 161 insertions, 220 deletions
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index ee2f4202d82a..c991cf212c6d 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -27,6 +27,9 @@ #include <linux/posix-timers.h> #include <linux/workqueue.h> #include <linux/freezer.h> +#include <linux/compat.h> + +#include "posix-timers.h" #define CREATE_TRACE_POINTS #include <trace/events/alarmtimer.h> @@ -45,11 +48,13 @@ static struct alarm_base { clockid_t base_clockid; } alarm_bases[ALARM_NUMTYPE]; +#if defined(CONFIG_POSIX_TIMERS) || defined(CONFIG_RTC_CLASS) /* freezer information to handle clock_nanosleep triggered wakeups */ static enum alarmtimer_type freezer_alarmtype; static ktime_t freezer_expires; static ktime_t freezer_delta; static DEFINE_SPINLOCK(freezer_delta_lock); +#endif static struct wakeup_source *ws; @@ -307,38 +312,6 @@ static int alarmtimer_resume(struct device *dev) } #endif -static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type) -{ - struct alarm_base *base; - unsigned long flags; - ktime_t delta; - - switch(type) { - case ALARM_REALTIME: - base = &alarm_bases[ALARM_REALTIME]; - type = ALARM_REALTIME_FREEZER; - break; - case ALARM_BOOTTIME: - base = &alarm_bases[ALARM_BOOTTIME]; - type = ALARM_BOOTTIME_FREEZER; - break; - default: - WARN_ONCE(1, "Invalid alarm type: %d\n", type); - return; - } - - delta = ktime_sub(absexp, base->gettime()); - - spin_lock_irqsave(&freezer_delta_lock, flags); - if (!freezer_delta || (delta < freezer_delta)) { - freezer_delta = delta; - freezer_expires = absexp; - freezer_alarmtype = type; - } - spin_unlock_irqrestore(&freezer_delta_lock, flags); -} - - /** * alarm_init - Initialize an alarm structure * @alarm: ptr to alarm to be initialized @@ -488,6 +461,38 @@ u64 alarm_forward_now(struct alarm *alarm, ktime_t interval) } EXPORT_SYMBOL_GPL(alarm_forward_now); +#ifdef CONFIG_POSIX_TIMERS + +static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type) +{ + struct alarm_base *base; + unsigned long flags; + ktime_t delta; + + switch(type) { + case ALARM_REALTIME: + base = &alarm_bases[ALARM_REALTIME]; + type = ALARM_REALTIME_FREEZER; + break; + case ALARM_BOOTTIME: + base = &alarm_bases[ALARM_BOOTTIME]; + type = ALARM_BOOTTIME_FREEZER; + break; + default: + WARN_ONCE(1, "Invalid alarm type: %d\n", type); + return; + } + + delta = ktime_sub(absexp, base->gettime()); + + spin_lock_irqsave(&freezer_delta_lock, flags); + if (!freezer_delta || (delta < freezer_delta)) { + freezer_delta = delta; + freezer_expires = absexp; + freezer_alarmtype = type; + } + spin_unlock_irqrestore(&freezer_delta_lock, flags); +} /** * clock2alarm - helper that converts from clockid to alarmtypes @@ -511,22 +516,26 @@ static enum alarmtimer_type clock2alarm(clockid_t clockid) static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm, ktime_t now) { - unsigned long flags; struct k_itimer *ptr = container_of(alarm, struct k_itimer, - it.alarm.alarmtimer); + it.alarm.alarmtimer); enum alarmtimer_restart result = ALARMTIMER_NORESTART; + unsigned long flags; + int si_private = 0; spin_lock_irqsave(&ptr->it_lock, flags); - if ((ptr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) { - if (IS_ENABLED(CONFIG_POSIX_TIMERS) && - posix_timer_event(ptr, 0) != 0) - ptr->it_overrun++; - } - /* Re-add periodic timers */ - if (ptr->it.alarm.interval) { - ptr->it_overrun += alarm_forward(alarm, now, - ptr->it.alarm.interval); + ptr->it_active = 0; + if (ptr->it_interval) + si_private = ++ptr->it_requeue_pending; + + if (posix_timer_event(ptr, si_private) && ptr->it_interval) { + /* + * Handle ignored signals and rearm the timer. This will go + * away once we handle ignored signals proper. + */ + ptr->it_overrun += alarm_forward_now(alarm, ptr->it_interval); + ++ptr->it_requeue_pending; + ptr->it_active = 1; result = ALARMTIMER_RESTART; } spin_unlock_irqrestore(&ptr->it_lock, flags); @@ -535,6 +544,72 @@ static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm, } /** + * alarm_timer_rearm - Posix timer callback for rearming timer + * @timr: Pointer to the posixtimer data struct + */ +static void alarm_timer_rearm(struct k_itimer *timr) +{ + struct alarm *alarm = &timr->it.alarm.alarmtimer; + + timr->it_overrun += alarm_forward_now(alarm, timr->it_interval); + alarm_start(alarm, alarm->node.expires); +} + +/** + * alarm_timer_forward - Posix timer callback for forwarding timer + * @timr: Pointer to the posixtimer data struct + * @now: Current time to forward the timer against + */ +static int alarm_timer_forward(struct k_itimer *timr, ktime_t now) +{ + struct alarm *alarm = &timr->it.alarm.alarmtimer; + + return (int) alarm_forward(alarm, timr->it_interval, now); +} + +/** + * alarm_timer_remaining - Posix timer callback to retrieve remaining time + * @timr: Pointer to the posixtimer data struct + * @now: Current time to calculate against + */ +static ktime_t alarm_timer_remaining(struct k_itimer *timr, ktime_t now) +{ + struct alarm *alarm = &timr->it.alarm.alarmtimer; + + return ktime_sub(now, alarm->node.expires); +} + +/** + * alarm_timer_try_to_cancel - Posix timer callback to cancel a timer + * @timr: Pointer to the posixtimer data struct + */ +static int alarm_timer_try_to_cancel(struct k_itimer *timr) +{ + return alarm_try_to_cancel(&timr->it.alarm.alarmtimer); +} + +/** + * alarm_timer_arm - Posix timer callback to arm a timer + * @timr: Pointer to the posixtimer data struct + * @expires: The new expiry time + * @absolute: Expiry value is absolute time + * @sigev_none: Posix timer does not deliver signals + */ +static void alarm_timer_arm(struct k_itimer *timr, ktime_t expires, + bool absolute, bool sigev_none) +{ + struct alarm *alarm = &timr->it.alarm.alarmtimer; + struct alarm_base *base = &alarm_bases[alarm->type]; + + if (!absolute) + expires = ktime_add_safe(expires, base->gettime()); + if (sigev_none) + alarm->node.expires = expires; + else + alarm_start(&timr->it.alarm.alarmtimer, expires); +} + +/** * alarm_clock_getres - posix getres interface * @which_clock: clockid * @tp: timespec to fill @@ -591,97 +666,6 @@ static int alarm_timer_create(struct k_itimer *new_timer) } /** - * alarm_timer_get - posix timer_get interface - * @new_timer: k_itimer pointer - * @cur_setting: itimerspec data to fill - * - * Copies out the current itimerspec data - */ -static void alarm_timer_get(struct k_itimer *timr, - struct itimerspec64 *cur_setting) -{ - ktime_t relative_expiry_time = - alarm_expires_remaining(&(timr->it.alarm.alarmtimer)); - - if (ktime_to_ns(relative_expiry_time) > 0) { - cur_setting->it_value = ktime_to_timespec64(relative_expiry_time); - } else { - cur_setting->it_value.tv_sec = 0; - cur_setting->it_value.tv_nsec = 0; - } - - cur_setting->it_interval = ktime_to_timespec64(timr->it.alarm.interval); -} - -/** - * alarm_timer_del - posix timer_del interface - * @timr: k_itimer pointer to be deleted - * - * Cancels any programmed alarms for the given timer. - */ -static int alarm_timer_del(struct k_itimer *timr) -{ - if (!rtcdev) - return -ENOTSUPP; - - if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0) - return TIMER_RETRY; - - return 0; -} - -/** - * alarm_timer_set - posix timer_set interface - * @timr: k_itimer pointer to be deleted - * @flags: timer flags - * @new_setting: itimerspec to be used - * @old_setting: itimerspec being replaced - * - * Sets the timer to new_setting, and starts the timer. - */ -static int alarm_timer_set(struct k_itimer *timr, int flags, - struct itimerspec64 *new_setting, - struct itimerspec64 *old_setting) -{ - ktime_t exp; - - if (!rtcdev) - return -ENOTSUPP; - - if (flags & ~TIMER_ABSTIME) - return -EINVAL; - - if (old_setting) - alarm_timer_get(timr, old_setting); - - /* If the timer was already set, cancel it */ - if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0) - return TIMER_RETRY; - - /* start the timer */ - timr->it.alarm.interval = timespec64_to_ktime(new_setting->it_interval); - - /* - * Rate limit to the tick as a hot fix to prevent DOS. Will be - * mopped up later. - */ - if (timr->it.alarm.interval < TICK_NSEC) - timr->it.alarm.interval = TICK_NSEC; - - exp = timespec64_to_ktime(new_setting->it_value); - /* Convert (if necessary) to absolute time */ - if (flags != TIMER_ABSTIME) { - ktime_t now; - - now = alarm_bases[timr->it.alarm.alarmtimer.type].gettime(); - exp = ktime_add_safe(now, exp); - } - - alarm_start(&timr->it.alarm.alarmtimer, exp); - return 0; -} - -/** * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep * @alarm: ptr to alarm that fired * @@ -705,8 +689,10 @@ static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm, * * Sets the alarm timer and sleeps until it is fired or interrupted. */ -static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp) +static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp, + enum alarmtimer_type type) { + struct restart_block *restart; alarm->data = (void *)current; do { set_current_state(TASK_INTERRUPTIBLE); @@ -719,36 +705,25 @@ static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp) __set_current_state(TASK_RUNNING); - return (alarm->data == NULL); -} - - -/** - * update_rmtp - Update remaining timespec value - * @exp: expiration time - * @type: timer type - * @rmtp: user pointer to remaining timepsec value - * - * Helper function that fills in rmtp value with time between - * now and the exp value - */ -static int update_rmtp(ktime_t exp, enum alarmtimer_type type, - struct timespec __user *rmtp) -{ - struct timespec rmt; - ktime_t rem; - - rem = ktime_sub(exp, alarm_bases[type].gettime()); - - if (rem <= 0) + if (!alarm->data) return 0; - rmt = ktime_to_timespec(rem); - if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) - return -EFAULT; + if (freezing(current)) + alarmtimer_freezerset(absexp, type); + restart = ¤t->restart_block; + if (restart->nanosleep.type != TT_NONE) { + struct timespec rmt; + ktime_t rem; + + rem = ktime_sub(absexp, alarm_bases[type].gettime()); - return 1; + if (rem <= 0) + return 0; + rmt = ktime_to_timespec(rem); + return nanosleep_copyout(restart, &rmt); + } + return -ERESTART_RESTARTBLOCK; } /** @@ -760,32 +735,12 @@ static int update_rmtp(ktime_t exp, enum alarmtimer_type type, static long __sched alarm_timer_nsleep_restart(struct restart_block *restart) { enum alarmtimer_type type = restart->nanosleep.clockid; - ktime_t exp; - struct timespec __user *rmtp; + ktime_t exp = restart->nanosleep.expires; struct alarm alarm; - int ret = 0; - exp = restart->nanosleep.expires; alarm_init(&alarm, type, alarmtimer_nsleep_wakeup); - if (alarmtimer_do_nsleep(&alarm, exp)) - goto out; - - if (freezing(current)) - alarmtimer_freezerset(exp, type); - - rmtp = restart->nanosleep.rmtp; - if (rmtp) { - ret = update_rmtp(exp, type, rmtp); - if (ret <= 0) - goto out; - } - - - /* The other values in restart are already filled in */ - ret = -ERESTART_RESTARTBLOCK; -out: - return ret; + return alarmtimer_do_nsleep(&alarm, exp, type); } /** @@ -798,11 +753,10 @@ out: * Handles clock_nanosleep calls against _ALARM clockids */ static int alarm_timer_nsleep(const clockid_t which_clock, int flags, - struct timespec64 *tsreq, - struct timespec __user *rmtp) + const struct timespec64 *tsreq) { enum alarmtimer_type type = clock2alarm(which_clock); - struct restart_block *restart; + struct restart_block *restart = ¤t->restart_block; struct alarm alarm; ktime_t exp; int ret = 0; @@ -825,35 +779,36 @@ static int alarm_timer_nsleep(const clockid_t which_clock, int flags, exp = ktime_add(now, exp); } - if (alarmtimer_do_nsleep(&alarm, exp)) - goto out; - - if (freezing(current)) - alarmtimer_freezerset(exp, type); + ret = alarmtimer_do_nsleep(&alarm, exp, type); + if (ret != -ERESTART_RESTARTBLOCK) + return ret; /* abs timers don't set remaining time or restart */ - if (flags == TIMER_ABSTIME) { - ret = -ERESTARTNOHAND; - goto out; - } + if (flags == TIMER_ABSTIME) + return -ERESTARTNOHAND; - if (rmtp) { - ret = update_rmtp(exp, type, rmtp); - if (ret <= 0) - goto out; - } - - restart = ¤t->restart_block; restart->fn = alarm_timer_nsleep_restart; restart->nanosleep.clockid = type; restart->nanosleep.expires = exp; - restart->nanosleep.rmtp = rmtp; - ret = -ERESTART_RESTARTBLOCK; - -out: return ret; } +const struct k_clock alarm_clock = { + .clock_getres = alarm_clock_getres, + .clock_get = alarm_clock_get, + .timer_create = alarm_timer_create, + .timer_set = common_timer_set, + .timer_del = common_timer_del, + .timer_get = common_timer_get, + .timer_arm = alarm_timer_arm, + .timer_rearm = alarm_timer_rearm, + .timer_forward = alarm_timer_forward, + .timer_remaining = alarm_timer_remaining, + .timer_try_to_cancel = alarm_timer_try_to_cancel, + .nsleep = alarm_timer_nsleep, +}; +#endif /* CONFIG_POSIX_TIMERS */ + /* Suspend hook structures */ static const struct dev_pm_ops alarmtimer_pm_ops = { @@ -879,23 +834,9 @@ static int __init alarmtimer_init(void) struct platform_device *pdev; int error = 0; int i; - struct k_clock alarm_clock = { - .clock_getres = alarm_clock_getres, - .clock_get = alarm_clock_get, - .timer_create = alarm_timer_create, - .timer_set = alarm_timer_set, - .timer_del = alarm_timer_del, - .timer_get = alarm_timer_get, - .nsleep = alarm_timer_nsleep, - }; alarmtimer_rtc_timer_init(); - if (IS_ENABLED(CONFIG_POSIX_TIMERS)) { - posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock); - posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock); - } - /* Initialize alarm bases */ alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME; alarm_bases[ALARM_REALTIME].gettime = &ktime_get_real; |