cregit-Linux how code gets into the kernel

Release 4.15 kernel/time/posix-timers.c

Directory: kernel/time
/*
 * linux/kernel/posix-timers.c
 *
 *
 * 2002-10-15  Posix Clocks & timers
 *                           by George Anzinger george@mvista.com
 *
 *                           Copyright (C) 2002 2003 by MontaVista Software.
 *
 * 2004-06-01  Fix CLOCK_REALTIME clock/timer TIMER_ABSTIME bug.
 *                           Copyright (C) 2004 Boris Hu
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * MontaVista Software | 1237 East Arques Avenue | Sunnyvale | CA 94085 | USA
 */

/* These are all the functions necessary to implement
 * POSIX clocks & timers
 */
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/mutex.h>
#include <linux/sched/task.h>

#include <linux/uaccess.h>
#include <linux/list.h>
#include <linux/init.h>
#include <linux/compiler.h>
#include <linux/hash.h>
#include <linux/posix-clock.h>
#include <linux/posix-timers.h>
#include <linux/syscalls.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
#include <linux/export.h>
#include <linux/hashtable.h>
#include <linux/compat.h>

#include "timekeeping.h"
#include "posix-timers.h"

/*
 * Management arrays for POSIX timers. Timers are now kept in static hash table
 * with 512 entries.
 * Timer ids are allocated by local routine, which selects proper hash head by
 * key, constructed from current->signal address and per signal struct counter.
 * This keeps timer ids unique per process, but now they can intersect between
 * processes.
 */

/*
 * Lets keep our timers in a slab cache :-)
 */

static struct kmem_cache *posix_timers_cache;

static DEFINE_HASHTABLE(posix_timers_hashtable, 9);
static DEFINE_SPINLOCK(hash_lock);


static const struct k_clock * const posix_clocks[];
static const struct k_clock *clockid_to_kclock(const clockid_t id);


static const struct k_clock clock_realtime, clock_monotonic;

/*
 * we assume that the new SIGEV_THREAD_ID shares no bits with the other
 * SIGEV values.  Here we put out an error if this assumption fails.
 */
#if SIGEV_THREAD_ID != (SIGEV_THREAD_ID & \
                       ~(SIGEV_SIGNAL | SIGEV_NONE | SIGEV_THREAD))
#error "SIGEV_THREAD_ID must not share bit with other SIGEV values!"
#endif

/*
 * parisc wants ENOTSUP instead of EOPNOTSUPP
 */
#ifndef ENOTSUP

# define ENANOSLEEP_NOTSUP EOPNOTSUPP
#else

# define ENANOSLEEP_NOTSUP ENOTSUP
#endif

/*
 * The timer ID is turned into a timer address by idr_find().
 * Verifying a valid ID consists of:
 *
 * a) checking that idr_find() returns other than -1.
 * b) checking that the timer id matches the one in the timer itself.
 * c) that the timer owner is in the callers thread group.
 */

/*
 * CLOCKs: The POSIX standard calls for a couple of clocks and allows us
 *          to implement others.  This structure defines the various
 *          clocks.
 *
 * RESOLUTION: Clock resolution is used to round up timer and interval
 *          times, NOT to report clock times, which are reported with as
 *          much resolution as the system can muster.  In some cases this
 *          resolution may depend on the underlying clock hardware and
 *          may not be quantifiable until run time, and only then is the
 *          necessary code is written.  The standard says we should say
 *          something about this issue in the documentation...
 *
 * FUNCTIONS: The CLOCKs structure defines possible functions to
 *          handle various clock functions.
 *
 *          The standard POSIX timer management code assumes the
 *          following: 1.) The k_itimer struct (sched.h) is used for
 *          the timer.  2.) The list, it_lock, it_clock, it_id and
 *          it_pid fields are not modified by timer code.
 *
 * Permissions: It is assumed that the clock_settime() function defined
 *          for each clock will take care of permission checks.  Some
 *          clocks may be set able by any user (i.e. local process
 *          clocks) others not.  Currently the only set able clock we
 *          have is CLOCK_REALTIME and its high res counter part, both of
 *          which we beg off on and pass to do_sys_settimeofday().
 */
static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags);


#define lock_timer(tid, flags)						   \
({      struct k_itimer *__timr;                                           \
        __cond_lock(&__timr->it_lock, __timr = __lock_timer(tid, flags));  \
        __timr;                                                            \
})


static int hash(struct signal_struct *sig, unsigned int nr) { return hash_32(hash32_ptr(sig) ^ nr, HASH_BITS(posix_timers_hashtable)); }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov31100.00%1100.00%
Total31100.00%1100.00%


static struct k_itimer *__posix_timers_find(struct hlist_head *head, struct signal_struct *sig, timer_t id) { struct k_itimer *timer; hlist_for_each_entry_rcu(timer, head, t_hash) { if ((timer->it_signal == sig) && (timer->it_id == id)) return timer; } return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov60100.00%1100.00%
Total60100.00%1100.00%


static struct k_itimer *posix_timer_by_id(timer_t id) { struct signal_struct *sig = current->signal; struct hlist_head *head = &posix_timers_hashtable[hash(sig, id)]; return __posix_timers_find(head, sig, id); }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov46100.00%1100.00%
Total46100.00%1100.00%


static int posix_timer_add(struct k_itimer *timer) { struct signal_struct *sig = current->signal; int first_free_id = sig->posix_timer_id; struct hlist_head *head; int ret = -ENOENT; do { spin_lock(&hash_lock); head = &posix_timers_hashtable[hash(sig, sig->posix_timer_id)]; if (!__posix_timers_find(head, sig, sig->posix_timer_id)) { hlist_add_head_rcu(&timer->t_hash, head); ret = sig->posix_timer_id; } if (++sig->posix_timer_id < 0) sig->posix_timer_id = 0; if ((sig->posix_timer_id == first_free_id) && (ret == -ENOENT)) /* Loop over all possible ids completed */ ret = -EAGAIN; spin_unlock(&hash_lock); } while (ret == -ENOENT); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Pavel Emelyanov149100.00%1100.00%
Total149100.00%1100.00%


static inline void unlock_timer(struct k_itimer *timr, unsigned long flags) { spin_unlock_irqrestore(&timr->it_lock, flags); }

Contributors

PersonTokensPropCommitsCommitProp
Roland McGrath26100.00%1100.00%
Total26100.00%1100.00%

/* Get clock_realtime */
static int posix_clock_realtime_get(clockid_t which_clock, struct timespec64 *tp) { ktime_get_real_ts64(tp); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner2090.91%150.00%
Deepa Dinamani29.09%150.00%
Total22100.00%2100.00%

/* Set clock_realtime */
static int posix_clock_realtime_set(const clockid_t which_clock, const struct timespec64 *tp) { return do_sys_settimeofday64(tp, NULL); }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner1979.17%133.33%
Deepa Dinamani520.83%266.67%
Total24100.00%3100.00%


static int posix_clock_realtime_adj(const clockid_t which_clock, struct timex *t) { return do_adjtimex(t); }

Contributors

PersonTokensPropCommitsCommitProp
Richard Cochran21100.00%1100.00%
Total21100.00%1100.00%

/* * Get monotonic time for posix timers */
static int posix_ktime_get_ts(clockid_t which_clock, struct timespec64 *tp) { ktime_get_ts64(tp); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner2090.91%150.00%
Deepa Dinamani29.09%150.00%
Total22100.00%2100.00%

/* * Get monotonic-raw time for posix timers */
static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec64 *tp) { getrawmonotonic64(tp); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
John Stultz2090.91%150.00%
Deepa Dinamani29.09%150.00%
Total22100.00%2100.00%


static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec64 *tp) { *tp = current_kernel_time64(); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
John Stultz2191.30%150.00%
Deepa Dinamani28.70%150.00%
Total23100.00%2100.00%


static int posix_get_monotonic_coarse(clockid_t which_clock, struct timespec64 *tp) { *tp = get_monotonic_coarse64(); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
John Stultz2191.30%150.00%
Deepa Dinamani28.70%150.00%
Total23100.00%2100.00%


static int posix_get_coarse_res(const clockid_t which_clock, struct timespec64 *tp) { *tp = ktime_to_timespec64(KTIME_LOW_RES); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
John Stultz2388.46%133.33%
Deepa Dinamani27.69%133.33%
H Hartley Sweeten13.85%133.33%
Total26100.00%3100.00%


static int posix_get_boottime(const clockid_t which_clock, struct timespec64 *tp) { get_monotonic_boottime64(tp); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
John Stultz2191.30%150.00%
Deepa Dinamani28.70%150.00%
Total23100.00%2100.00%


static int posix_get_tai(clockid_t which_clock, struct timespec64 *tp) { timekeeping_clocktai64(tp); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
John Stultz2090.91%150.00%
Deepa Dinamani29.09%150.00%
Total22100.00%2100.00%


static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp) { tp->tv_sec = 0; tp->tv_nsec = hrtimer_resolution; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner2896.55%150.00%
Deepa Dinamani13.45%150.00%
Total29100.00%2100.00%

/* * Initialize everything, well, just everything in Posix clocks/timers ;) */
static __init int init_posix_timers(void) { posix_timers_cache = kmem_cache_create("posix_timers_cache", sizeof (struct k_itimer), 0, SLAB_PANIC, NULL); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner2993.55%266.67%
George Anzinger26.45%133.33%
Total31100.00%3100.00%

__initcall(init_posix_timers);
static void common_hrtimer_rearm(struct k_itimer *timr) { struct hrtimer *timer = &timr->it.real.timer; if (!timr->it_interval) return; timr->it_overrun += (unsigned int) hrtimer_forward(timer, timer->base->get_time(), timr->it_interval); hrtimer_restart(timer); }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner5893.55%466.67%
George Anzinger34.84%116.67%
Christoph Hellwig11.61%116.67%
Total62100.00%6100.00%

/* * This function is exported for use by the signal deliver code. It is * called just prior to the info block being released and passes that * block to us. It's function is to update the overrun entry AND to * restart the timer. It should only be called if the timer is to be * restarted (i.e. we have flagged this in the sys_private entry of the * info block). * * To protect against the timer going away while the interrupt is queued, * we require that the it_requeue_pending flag be set. */
void posixtimer_rearm(struct siginfo *info) { struct k_itimer *timr; unsigned long flags; timr = lock_timer(info->si_tid, &flags); if (!timr) return; if (timr->it_requeue_pending == info->si_sys_private) { timr->kclock->timer_rearm(timr); timr->it_active = 1; timr->it_overrun_last = timr->it_overrun; timr->it_overrun = -1; ++timr->it_requeue_pending; info->si_overrun += timr->it_overrun_last; } unlock_timer(timr, flags); }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner9696.97%583.33%
John Stultz33.03%116.67%
Total99100.00%6100.00%


int posix_timer_event(struct k_itimer *timr, int si_private) { struct task_struct *task; int shared, ret = -1; /* * FIXME: if ->sigq is queued we can race with * dequeue_signal()->posixtimer_rearm(). * * If dequeue_signal() sees the "right" value of * si_sys_private it calls posixtimer_rearm(). * We re-queue ->sigq and drop ->it_lock(). * posixtimer_rearm() locks the timer * and re-schedules it while ->sigq is pending. * Not really bad, but not that we want. */ timr->sigq->info.si_sys_private = si_private; rcu_read_lock(); task = pid_task(timr->it_pid, PIDTYPE_PID); if (task) { shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID); ret = send_sigqueue(timr->sigq, task, shared); } rcu_read_unlock(); /* If we failed to send the signal the timer stops. */ return ret > 0; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner8392.22%266.67%
John Stultz77.78%133.33%
Total90100.00%3100.00%

/* * This function gets called when a POSIX.1b interval timer expires. It * is used as a callback from the kernel internal timer. The * run_timer_list code ALWAYS calls with interrupts on. * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers. */
static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer) { struct k_itimer *timr; unsigned long flags; int si_private = 0; enum hrtimer_restart ret = HRTIMER_NORESTART; timr = container_of(timer, struct k_itimer, it.real.timer); spin_lock_irqsave(&timr->it_lock, flags); timr->it_active = 0; if (timr->it_interval != 0) si_private = ++timr->it_requeue_pending; if (posix_timer_event(timr, si_private)) { /* * signal was not sent because of sig_ignor * we will not get a call back to restart it AND * it should be restarted. */ if (timr->it_interval != 0) { ktime_t now = hrtimer_cb_get_time(timer); /* * FIXME: What we really want, is to stop this * timer completely and restart it in case the * SIG_IGN is removed. This is a non trivial * change which involves sighand locking * (sigh !), which we don't want to do late in * the release cycle. * * For now we just let timers with an interval * less than a jiffie expire every jiffie to * avoid softirq starvation in case of SIG_IGN * and a very small interval, which would put * the timer right back on the softirq pending * list. By moving now ahead of time we trick * hrtimer_forward() to expire the timer * later, while we still maintain the overrun * accuracy, but have some inconsistency in * the timer_gettime() case. This is at least * better than a starved softirq. A more * complex fix which solves also another related * inconsistency is already in the pipeline. */ #ifdef CONFIG_HIGH_RES_TIMERS { ktime_t kj = NSEC_PER_SEC / HZ; if (timr->it_interval < kj) now = ktime_add(now, kj); } #endif timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, timr->it_interval); ret = HRTIMER_RESTART; ++timr->it_requeue_pending; timr->it_active = 1; } } unlock_timer(timr, flags); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner14980.54%430.77%
George Anzinger2111.35%323.08%
John Stultz94.86%323.08%
Davide Libenzi42.16%17.69%
Roman Zippel10.54%17.69%
Christoph Hellwig10.54%17.69%
Total185100.00%13100.00%


static struct pid *good_sigevent(sigevent_t * event) { struct task_struct *rtn = current->group_leader; switch (event->sigev_notify) { case SIGEV_SIGNAL | SIGEV_THREAD_ID: rtn = find_task_by_vpid(event->sigev_notify_thread_id); if (!rtn || !same_thread_group(rtn, current)) return NULL; /* FALLTHRU */ case SIGEV_SIGNAL: case SIGEV_THREAD: if (event->sigev_signo <= 0 || event->sigev_signo > SIGRTMAX) return NULL; /* FALLTHRU */ case SIGEV_NONE: return task_pid(rtn); default: return NULL; } }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner7779.38%360.00%
George Anzinger1818.56%120.00%
Roland McGrath22.06%120.00%
Total97100.00%5100.00%


static struct k_itimer * alloc_posix_timer(void) { struct k_itimer *tmr; tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL); if (!tmr) return tmr; if (unlikely(!(tmr->sigq = sigqueue_alloc()))) { kmem_cache_free(posix_timers_cache, tmr); return NULL; } memset(&tmr->sigq->info, 0, sizeof(siginfo_t)); return tmr; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner4860.76%112.50%
Oleg Nesterov2025.32%450.00%
George Anzinger78.86%112.50%
Christoph Lameter22.53%112.50%
Andrew Morton22.53%112.50%
Total79100.00%8100.00%


static void k_itimer_rcu_free(struct rcu_head *head) { struct k_itimer *tmr = container_of(head, struct k_itimer, it.rcu); kmem_cache_free(posix_timers_cache, tmr); }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner1748.57%250.00%
Roman Zippel1131.43%125.00%
George Anzinger720.00%125.00%
Total35100.00%4100.00%

#define IT_ID_SET 1 #define IT_ID_NOT_SET 0
static void release_posix_timer(struct k_itimer *tmr, int it_id_set) { if (it_id_set) { unsigned long flags; spin_lock_irqsave(&hash_lock, flags); hlist_del_rcu(&tmr->t_hash); spin_unlock_irqrestore(&hash_lock, flags); } put_pid(tmr->it_pid); sigqueue_free(tmr->sigq); call_rcu(&tmr->it.rcu, k_itimer_rcu_free); }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner6993.24%375.00%
Christoph Lameter56.76%125.00%
Total74100.00%4100.00%


static int common_timer_create(struct k_itimer *new_timer) { hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner2578.12%240.00%
George Anzinger515.62%120.00%
Davide Libenzi13.12%120.00%
Roman Zippel13.12%120.00%
Total32100.00%5100.00%

/* Create a POSIX.1b interval timer. */
static int do_timer_create(clockid_t which_clock, struct sigevent *event, timer_t __user *created_timer_id) { const struct k_clock *kc = clockid_to_kclock(which_clock); struct k_itimer *new_timer; int error, new_timer_id; int it_id_set = IT_ID_NOT_SET; if (!kc) return -EINVAL; if (!kc->timer_create) return -EOPNOTSUPP; new_timer = alloc_posix_timer(); if (unlikely(!new_timer)) return -EAGAIN; spin_lock_init(&new_timer->it_lock); new_timer_id = posix_timer_add(new_timer); if (new_timer_id < 0) { error = new_timer_id; goto out; } it_id_set = IT_ID_SET; new_timer->it_id = (timer_t) new_timer_id; new_timer->it_clock = which_clock; new_timer->kclock = kc; new_timer->it_overrun = -1; if (event) { rcu_read_lock(); new_timer->it_pid = get_pid(good_sigevent(event)); rcu_read_unlock(); if (!new_timer->it_pid) { error = -EINVAL; goto out; } new_timer->it_sigev_notify = event->sigev_notify; new_timer->sigq->info.si_signo = event->sigev_signo; new_timer->sigq->info.si_value = event->sigev_value; } else { new_timer->it_sigev_notify = SIGEV_SIGNAL; new_timer->sigq->info.si_signo = SIGALRM; memset(&new_timer->sigq->info.si_value, 0, sizeof(sigval_t)); new_timer->sigq->info.si_value.sival_int = new_timer->it_id; new_timer->it_pid = get_pid(task_tgid(current)); } new_timer->sigq->info.si_tid = new_timer->it_id; new_timer->sigq->info.si_code = SI_TIMER; if (copy_to_user(created_timer_id, &new_timer_id, sizeof (new_timer_id))) { error = -EFAULT; goto out; } error = kc->timer_create(new_timer); if (error) goto out; spin_lock_irq(&current->sighand->siglock); new_timer->it_signal = current->signal; list_add(&new_timer->list, &current->signal->posix_timers); spin_unlock_irq(&current->sighand->siglock); return 0; /* * In the case of the timer belonging to another task, after * the task is unlocked, the timer is owned by the other task * and may cease to exist at any time. Don't use or modify * new_timer after the unlock call. */ out: release_posix_timer(new_timer, it_id_set); return error; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner12631.27%418.18%
Al Viro7719.11%14.55%
Oleg Nesterov7217.87%836.36%
George Anzinger5012.41%14.55%
Andrey Vagin389.43%29.09%
Andrew Morton194.71%29.09%
Jim Houston92.23%14.55%
Corey Minyard71.74%14.55%
Eric Dumazet30.74%14.55%
Dan Carpenter20.50%14.55%
Total403100.00%22100.00%

SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock, struct sigevent __user *, timer_event_spec, timer_t __user *, created_timer_id) { if (timer_event_spec) { sigevent_t event; if (copy_from_user(&event, timer_event_spec, sizeof (event))) return -EFAULT; return do_timer_create(which_clock, &event, created_timer_id); } return do_timer_create(which_clock, NULL, created_timer_id); } #ifdef CONFIG_COMPAT COMPAT_SYSCALL_DEFINE3(timer_create, clockid_t, which_clock, struct compat_sigevent __user *, timer_event_spec, timer_t __user *, created_timer_id) { if (timer_event_spec) { sigevent_t event; if (get_compat_sigevent(&event, timer_event_spec)) return -EFAULT; return do_timer_create(which_clock, &event, created_timer_id); } return do_timer_create(which_clock, NULL, created_timer_id); } #endif /* * Locking issues: We need to protect the result of the id look up until * we get the timer locked down so it is not deleted under us. The * removal is done under the idr spinlock so we use that here to bridge * the find to the timer lock. To avoid a dead lock, the timer id MUST * be release with out holding the timer lock. */
static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags) { struct k_itimer *timr; /* * timer_t could be any type >= int and we want to make sure any * @timer_id outside positive int range fails lookup. */ if ((unsigned long long)timer_id > INT_MAX) return NULL; rcu_read_lock(); timr = posix_timer_by_id(timer_id); if (timr) { spin_lock_irqsave(&timr->it_lock, *flags); if (timr->it_signal == current->signal) { rcu_read_unlock(); return timr; } spin_unlock_irqrestore(&timr->it_lock, *flags); } rcu_read_unlock(); return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
George Anzinger5556.12%111.11%
Tejun Heo1515.31%111.11%
Eric Dumazet1313.27%111.11%
Oleg Nesterov1010.20%222.22%
Thomas Gleixner22.04%111.11%
Pavel Emelyanov11.02%111.11%
Andi Kleen11.02%111.11%
Namhyung Kim11.02%111.11%
Total98100.00%9100.00%


static ktime_t common_hrtimer_remaining(struct k_itimer *timr, ktime_t now) { struct hrtimer *timer = &timr->it.real.timer; return __hrtimer_expires_remaining_adjusted(timer, now); }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner36100.00%1100.00%
Total36100.00%1100.00%


static int common_hrtimer_forward(struct k_itimer *timr, ktime_t now) { struct hrtimer *timer = &timr->it.real.timer; return (int)hrtimer_forward(timer, now, timr->it_interval); }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner43100.00%1100.00%
Total43100.00%1100.00%

/* * Get the time remaining on a POSIX.1b interval timer. This function * is ALWAYS called with spin_lock_irq on the timer, thus it must not * mess with irq. * * We have a couple of messes to clean up here. First there is the case * of a timer that has a requeue pending. These timers should appear to * be in the timer list with an expiry as if we were to requeue them * now. * * The second issue is the SIGEV_NONE timer which may be active but is * not really ever put in the timer list (to save system resources). * This timer may be expired, and if so, we will do it here. Otherwise * it is the same as a requeue pending timer WRT to what we should * report. */
void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting) { const struct k_clock *kc = timr->kclock; ktime_t now, remaining, iv; struct timespec64 ts64; bool sig_none; sig_none = timr->it_sigev_notify == SIGEV_NONE; iv = timr->it_interval; /* interval timer ? */ if (iv) { cur_setting->it_interval = ktime_to_timespec64(iv); } else if (!timr->it_active) { /* * SIGEV_NONE oneshot timers are never queued. Check them * below. */ if (!sig_none) return; } /* * The timespec64 based conversion is suboptimal, but it's not * worth to implement yet another callback. */ kc->clock_get(timr->it_clock, &ts64); now = timespec64_to_ktime(ts64); /* * When a requeue is pending or this is a SIGEV_NONE timer move the * expiry time forward by intervals, so expiry is > now. */ if (iv && (timr->it_requeue_pending & REQUEUE_PENDING || sig_none)) timr->it_overrun += kc->timer_forward(timr, now); remaining = kc->timer_remaining(timr, now); /* Return 0 only, when the timer is expired and not pending */ if (remaining <= 0) { /* * A single shot SIGEV_NONE timer must return 0, when * it is expired ! */ if (!sig_none) cur_setting->it_value.tv_nsec = 1; } else { cur_setting->it_value = ktime_to_timespec64(remaining); } }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner8949.44%545.45%
George Anzinger5228.89%218.18%
Roman Zippel3418.89%19.09%
Deepa Dinamani31.67%19.09%
Roland McGrath10.56%19.09%
Arjan van de Ven10.56%19.09%
Total180100.00%11100.00%

/* Get the time remaining on a POSIX.1b interval timer. */
static int do_timer_gettime(timer_t timer_id, struct itimerspec64 *setting) { struct k_itimer *timr; const struct k_clock *kc; unsigned long flags; int ret = 0; timr = lock_timer(timer_id, &flags); if (!timr) return -EINVAL; memset(setting, 0, sizeof(*setting)); kc = timr->kclock; if (WARN_ON_ONCE(!kc || !kc->timer_get)) ret = -EINVAL; else kc->timer_get(timr, setting); unlock_timer(timr, flags); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner4944.55%436.36%
George Anzinger3733.64%218.18%
Al Viro1917.27%19.09%
Roland McGrath21.82%19.09%
Deepa Dinamani10.91%19.09%
Andi Kleen10.91%19.09%
Christoph Hellwig10.91%19.09%
Total110100.00%11100.00%

/* Get the time remaining on a POSIX.1b interval timer. */ SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id, struct itimerspec __user *, setting) { struct itimerspec64 cur_setting; int ret = do_timer_gettime(timer_id, &cur_setting); if (!ret) { if (put_itimerspec64(&cur_setting, setting)) ret = -EFAULT; } return ret; } #ifdef CONFIG_COMPAT COMPAT_SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id, struct compat_itimerspec __user *, setting) { struct itimerspec64 cur_setting; int ret = do_timer_gettime(timer_id, &cur_setting); if (!ret) { if (put_compat_itimerspec64(&cur_setting, setting)) ret = -EFAULT; } return ret; } #endif /* * Get the number of overruns of a POSIX.1b interval timer. This is to * be the overrun of the timer last delivered. At the same time we are * accumulating overruns on the next timer. The overrun is frozen when * the signal is delivered, either at the notify time (if the info block * is not queued) or at the actual delivery time (as we are informed by * the call back to posixtimer_rearm(). So all we need to do is * to pick up the frozen overrun. */ SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id) { struct k_itimer *timr; int overrun; unsigned long flags; timr = lock_timer(timer_id, &flags); if (!timr) return -EINVAL; overrun = timr->it_overrun_last; unlock_timer(timr, flags); return overrun; }
static void common_hrtimer_arm(struct k_itimer *timr, ktime_t expires, bool absolute, bool sigev_none) { struct hrtimer *timer = &timr->it.real.timer; enum hrtimer_mode mode; mode = absolute ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL; /* * Posix magic: Relative CLOCK_REALTIME timers are not affected by * clock modifications, so they become CLOCK_MONOTONIC based under the * hood. See hrtimer_init(). Update timr->kclock, so the generic * functions which use timr->kclock->clock_get() work. * * Note: it_clock stays unmodified, because the next timer_set() might * use ABSTIME, so it needs to switch back. */ if (timr->it_clock == CLOCK_REALTIME) timr->kclock = absolute ? &clock_realtime : &clock_monotonic; hrtimer_init(&timr->it.real.timer, timr->it_clock, mode); timr->it.real.timer.function = posix_timer_fn; if (!absolute) expires = ktime_add_safe(expires, timer->base->get_time()); hrtimer_set_expires(timer, expires); if (!sigev_none) hrtimer_start_expires(timer, HRTIMER_MODE_ABS); }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner135100.00%2100.00%
Total135100.00%2100.00%


static int common_hrtimer_try_to_cancel(struct k_itimer *timr) { return hrtimer_try_to_cancel(&timr->it.real.timer); }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner24100.00%1100.00%
Total24100.00%1100.00%

/* Set a POSIX.1b interval timer. */
int common_timer_set(struct k_itimer *timr, int flags, struct itimerspec64 *new_setting, struct itimerspec64 *old_setting) { const struct k_clock *kc = timr->kclock; bool sigev_none; ktime_t expires; if (old_setting) common_timer_get(timr, old_setting); /* Prevent rearming by clearing the interval */ timr->it_interval = 0; /* * Careful here. On SMP systems the timer expiry function could be * active and spinning on timr->it_lock. */ if (kc->timer_try_to_cancel(timr) < 0) return TIMER_RETRY; timr->it_active = 0; timr->it_requeue_pending = (timr->it_requeue_pending + 2) & ~REQUEUE_PENDING; timr->it_overrun_last = 0; /* Switch off the timer 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); sigev_none = timr->it_sigev_notify == SIGEV_NONE; kc->timer_arm(timr, expires, flags & TIMER_ABSTIME, sigev_none); timr->it_active = !sigev_none; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
George Anzinger10058.14%425.00%
Thomas Gleixner6034.88%637.50%
Deepa Dinamani42.33%16.25%
Roland McGrath21.16%16.25%
Ingo Molnar21.16%16.25%
Oleg Nesterov21.16%16.25%
Andrew Morton10.58%16.25%
Arjan van de Ven10.58%16.25%
Total172100.00%16100.00%


static int do_timer_settime(timer_t timer_id, int flags, struct itimerspec64 *new_spec64, struct itimerspec64 *old_spec64) { const struct k_clock *kc; struct k_itimer *timr; unsigned long flag; int error = 0; if (!timespec64_valid(&new_spec64->it_interval) || !timespec64_valid(&new_spec64->it_value)) return -EINVAL; if (old_spec64) memset(old_spec64, 0, sizeof(*old_spec64)); retry: timr = lock_timer(timer_id, &flag); if (!timr) return -EINVAL; kc = timr->kclock; if (WARN_ON_ONCE(!kc || !kc->timer_set)) error = -EINVAL; else error = kc->timer_set(timr, flags, new_spec64, old_spec64); unlock_timer(timr, flag); if (error == TIMER_RETRY) { old_spec64 = NULL; // We already got the old time... goto retry; } return error; }

Contributors

PersonTokensPropCommitsCommitProp
George Anzinger7544.12%111.11%
Thomas Gleixner4425.88%333.33%
Al Viro3017.65%222.22%
Deepa Dinamani1911.18%111.11%
Roland McGrath10.59%111.11%
Ingo Molnar10.59%111.11%
Total170100.00%9100.00%

/* Set a POSIX.1b interval timer */ SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags, const struct itimerspec __user *, new_setting, struct itimerspec __user *, old_setting) { struct itimerspec64 new_spec, old_spec; struct itimerspec64 *rtn = old_setting ? &old_spec : NULL; int error = 0; if (!new_setting) return -EINVAL; if (get_itimerspec64(&new_spec, new_setting)) return -EFAULT; error = do_timer_settime(timer_id, flags, &new_spec, rtn); if (!error && old_setting) { if (put_itimerspec64(&old_spec, old_setting)) error = -EFAULT; } return error; } #ifdef CONFIG_COMPAT COMPAT_SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags, struct compat_itimerspec __user *, new, struct compat_itimerspec __user *, old) { struct itimerspec64 new_spec, old_spec; struct itimerspec64 *rtn = old ? &old_spec : NULL; int error = 0; if (!new) return -EINVAL; if (get_compat_itimerspec64(&new_spec, new)) return -EFAULT; error = do_timer_settime(timer_id, flags, &new_spec, rtn); if (!error && old) { if (put_compat_itimerspec64(&old_spec, old)) error = -EFAULT; } return error; } #endif
int common_timer_del(struct k_itimer *timer) { const struct k_clock *kc = timer->kclock; timer->it_interval = 0; if (kc->timer_try_to_cancel(timer) < 0) return TIMER_RETRY; timer->it_active = 0; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
George Anzinger2551.02%114.29%
Thomas Gleixner2040.82%342.86%
Oleg Nesterov24.08%114.29%
Roland McGrath24.08%228.57%
Total49100.00%7100.00%


static inline int timer_delete_hook(struct k_itimer *timer) { const struct k_clock *kc = timer->kclock; if (WARN_ON_ONCE(!kc || !kc->timer_del)) return -EINVAL; return kc->timer_del(timer); }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner2859.57%250.00%
Roland McGrath1838.30%125.00%
Christoph Hellwig12.13%125.00%
Total47100.00%4100.00%

/* Delete a POSIX.1b interval timer. */ SYSCALL_DEFINE1(timer_delete, timer_t, timer_id) { struct k_itimer *timer; unsigned long flags; retry_delete: timer = lock_timer(timer_id, &flags); if (!timer) return -EINVAL; if (timer_delete_hook(timer) == TIMER_RETRY) { unlock_timer(timer, flags); goto retry_delete; } spin_lock(&current->sighand->siglock); list_del(&timer->list); spin_unlock(&current->sighand->siglock); /* * This keeps any tasks waiting on the spin lock from thinking * they got something (see the lock code above). */ timer->it_signal = NULL; unlock_timer(timer, flags); release_posix_timer(timer, IT_ID_SET); return 0; } /* * return timer owned by the process, used by exit_itimers */
static void itimer_delete(struct k_itimer *timer) { unsigned long flags; retry_delete: spin_lock_irqsave(&timer->it_lock, flags); if (timer_delete_hook(timer) == TIMER_RETRY) { unlock_timer(timer, flags); goto retry_delete; } list_del(&timer->list); /* * This keeps any tasks waiting on the spin lock from thinking * they got something (see the lock code above). */ timer->it_signal = NULL; unlock_timer(timer, flags); release_posix_timer(timer, IT_ID_SET); }

Contributors

PersonTokensPropCommitsCommitProp
Andrew Morton5571.43%116.67%
George Anzinger1620.78%116.67%
Corey Minyard22.60%116.67%
Thomas Gleixner22.60%116.67%
Roland McGrath11.30%116.67%
Oleg Nesterov11.30%116.67%
Total77100.00%6100.00%

/* * This is called by do_exit or de_thread, only when there are no more * references to the shared signal_struct. */
void exit_itimers(struct signal_struct *sig) { struct k_itimer *tmr; while (!list_empty(&sig->posix_timers)) { tmr = list_entry(sig->posix_timers.next, struct k_itimer, list); itimer_delete(tmr); } }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner2244.90%120.00%
George Anzinger1836.73%120.00%
Roland McGrath510.20%120.00%
Andrew Morton36.12%120.00%
Ingo Molnar12.04%120.00%
Total49100.00%5100.00%

SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock, const struct timespec __user *, tp) { const struct k_clock *kc = clockid_to_kclock(which_clock); struct timespec64 new_tp; if (!kc || !kc->clock_set) return -EINVAL; if (get_timespec64(&new_tp, tp)) return -EFAULT; return kc->clock_set(which_clock, &new_tp); } SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock, struct timespec __user *,tp) { const struct k_clock *kc = clockid_to_kclock(which_clock); struct timespec64 kernel_tp; int error; if (!kc) return -EINVAL; error = kc->clock_get(which_clock, &kernel_tp); if (!error && put_timespec64(&kernel_tp, tp)) error = -EFAULT; return error; } SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock, struct timex __user *, utx) { const struct k_clock *kc = clockid_to_kclock(which_clock); struct timex ktx; int err; if (!kc) return -EINVAL; if (!kc->clock_adj) return -EOPNOTSUPP; if (copy_from_user(&ktx, utx, sizeof(ktx))) return -EFAULT; err = kc->clock_adj(which_clock, &ktx); if (err >= 0 && copy_to_user(utx, &ktx, sizeof(ktx))) return -EFAULT; return err; } SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock, struct timespec __user *, tp) { const struct k_clock *kc = clockid_to_kclock(which_clock); struct timespec64 rtn_tp; int error; if (!kc) return -EINVAL; error = kc->clock_getres(which_clock, &rtn_tp); if (!error && tp && put_timespec64(&rtn_tp, tp)) error = -EFAULT; return error; } #ifdef CONFIG_COMPAT COMPAT_SYSCALL_DEFINE2(clock_settime, clockid_t, which_clock, struct compat_timespec __user *, tp) { const struct k_clock *kc = clockid_to_kclock(which_clock); struct timespec64 ts; if (!kc || !kc->clock_set) return -EINVAL; if (compat_get_timespec64(&ts, tp)) return -EFAULT; return kc->clock_set(which_clock, &ts); } COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t, which_clock, struct compat_timespec __user *, tp) { const struct k_clock *kc = clockid_to_kclock(which_clock); struct timespec64 ts; int err; if (!kc) return -EINVAL; err = kc->clock_get(which_clock, &ts); if (!err && compat_put_timespec64(&ts, tp)) err = -EFAULT; return err; } COMPAT_SYSCALL_DEFINE2(clock_adjtime, clockid_t, which_clock, struct compat_timex __user *, utp) { const struct k_clock *kc = clockid_to_kclock(which_clock); struct timex ktx; int err; if (!kc) return -EINVAL; if (!kc->clock_adj) return -EOPNOTSUPP; err = compat_get_timex(&ktx, utp); if (err) return err; err = kc->clock_adj(which_clock, &ktx); if (err >= 0) err = compat_put_timex(utp, &ktx); return err; } COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock, struct compat_timespec __user *, tp) { const struct k_clock *kc = clockid_to_kclock(which_clock); struct timespec64 ts; int err; if (!kc) return -EINVAL; err = kc->clock_getres(which_clock, &ts); if (!err && tp && compat_put_timespec64(&ts, tp)) return -EFAULT; return err; } #endif /* * nanosleep for monotonic and realtime clocks */
static int common_nsleep(const clockid_t which_clock, int flags, const struct timespec64 *rqtp) { return hrtimer_nanosleep(rqtp, flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL, which_clock); }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner35100.00%2100.00%
Total35100.00%2100.00%

SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags, const struct timespec __user *, rqtp, struct timespec __user *, rmtp) { const struct k_clock *kc = clockid_to_kclock(which_clock); struct timespec64 t; if (!kc) return -EINVAL; if (!kc->nsleep) return -ENANOSLEEP_NOTSUP; if (get_timespec64(&t, rqtp)) return -EFAULT; if (!timespec64_valid(&t)) return -EINVAL; if (flags & TIMER_ABSTIME) rmtp = NULL; current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE; current->restart_block.nanosleep.rmtp = rmtp; return kc->nsleep(which_clock, flags, &t); } #ifdef CONFIG_COMPAT COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags, struct compat_timespec __user *, rqtp, struct compat_timespec __user *, rmtp) { const struct k_clock *kc = clockid_to_kclock(which_clock); struct timespec64 t; if (!kc) return -EINVAL; if (!kc->nsleep) return -ENANOSLEEP_NOTSUP; if (compat_get_timespec64(&t, rqtp)) return -EFAULT; if (!timespec64_valid(&t)) return -EINVAL; if (flags & TIMER_ABSTIME) rmtp = NULL; current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE; current->restart_block.nanosleep.compat_rmtp = rmtp; return kc->nsleep(which_clock, flags, &t); } #endif static const struct k_clock clock_realtime = { .clock_getres = posix_get_hrtimer_res, .clock_get = posix_clock_realtime_get, .clock_set = posix_clock_realtime_set, .clock_adj = posix_clock_realtime_adj, .nsleep = common_nsleep, .timer_create = common_timer_create, .timer_set = common_timer_set, .timer_get = common_timer_get, .timer_del = common_timer_del, .timer_rearm = common_hrtimer_rearm, .timer_forward = common_hrtimer_forward, .timer_remaining = common_hrtimer_remaining, .timer_try_to_cancel = common_hrtimer_try_to_cancel, .timer_arm = common_hrtimer_arm, }; static const struct k_clock clock_monotonic = { .clock_getres = posix_get_hrtimer_res, .clock_get = posix_ktime_get_ts, .nsleep = common_nsleep, .timer_create = common_timer_create, .timer_set = common_timer_set, .timer_get = common_timer_get, .timer_del = common_timer_del, .timer_rearm = common_hrtimer_rearm, .timer_forward = common_hrtimer_forward, .timer_remaining = common_hrtimer_remaining, .timer_try_to_cancel = common_hrtimer_try_to_cancel, .timer_arm = common_hrtimer_arm, }; static const struct k_clock clock_monotonic_raw = { .clock_getres = posix_get_hrtimer_res, .clock_get = posix_get_monotonic_raw, }; static const struct k_clock clock_realtime_coarse = { .clock_getres = posix_get_coarse_res, .clock_get = posix_get_realtime_coarse, }; static const struct k_clock clock_monotonic_coarse = { .clock_getres = posix_get_coarse_res, .clock_get = posix_get_monotonic_coarse, }; static const struct k_clock clock_tai = { .clock_getres = posix_get_hrtimer_res, .clock_get = posix_get_tai, .nsleep = common_nsleep, .timer_create = common_timer_create, .timer_set = common_timer_set, .timer_get = common_timer_get, .timer_del = common_timer_del, .timer_rearm = common_hrtimer_rearm, .timer_forward = common_hrtimer_forward, .timer_remaining = common_hrtimer_remaining, .timer_try_to_cancel = common_hrtimer_try_to_cancel, .timer_arm = common_hrtimer_arm, }; static const struct k_clock clock_boottime = { .clock_getres = posix_get_hrtimer_res, .clock_get = posix_get_boottime, .nsleep = common_nsleep, .timer_create = common_timer_create, .timer_set = common_timer_set, .timer_get = common_timer_get, .timer_del = common_timer_del, .timer_rearm = common_hrtimer_rearm, .timer_forward = common_hrtimer_forward, .timer_remaining = common_hrtimer_remaining, .timer_try_to_cancel = common_hrtimer_try_to_cancel, .timer_arm = common_hrtimer_arm, }; static const struct k_clock * const posix_clocks[] = { [CLOCK_REALTIME] = &clock_realtime, [CLOCK_MONOTONIC] = &clock_monotonic, [CLOCK_PROCESS_CPUTIME_ID] = &clock_process, [CLOCK_THREAD_CPUTIME_ID] = &clock_thread, [CLOCK_MONOTONIC_RAW] = &clock_monotonic_raw, [CLOCK_REALTIME_COARSE] = &clock_realtime_coarse, [CLOCK_MONOTONIC_COARSE] = &clock_monotonic_coarse, [CLOCK_BOOTTIME] = &clock_boottime, [CLOCK_REALTIME_ALARM] = &alarm_clock, [CLOCK_BOOTTIME_ALARM] = &alarm_clock, [CLOCK_TAI] = &clock_tai, };
static const struct k_clock *clockid_to_kclock(const clockid_t id) { if (id < 0) return (id & CLOCKFD_MASK) == CLOCKFD ? &clock_posix_dynamic : &clock_posix_cpu; if (id >= ARRAY_SIZE(posix_clocks) || !posix_clocks[id]) return NULL; return posix_clocks[id]; }

Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner4882.76%450.00%
George Anzinger610.34%112.50%
Toyo Abe23.45%112.50%
Christoph Hellwig11.72%112.50%
Andrew Morton11.72%112.50%
Total58100.00%8100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Thomas Gleixner223342.67%3731.36%
Al Viro98718.86%86.78%
George Anzinger71113.59%54.24%
Pavel Emelyanov3005.73%10.85%
John Stultz1462.79%54.24%
Andrew Morton1352.58%43.39%
Richard Cochran1302.48%32.54%
Deepa Dinamani1152.20%86.78%
Oleg Nesterov1082.06%1311.02%
Roland McGrath931.78%32.54%
Heiko Carstens500.96%10.85%
Roman Zippel470.90%43.39%
Andrey Vagin380.73%21.69%
Linus Torvalds180.34%21.69%
Eric Dumazet160.31%10.85%
Tejun Heo150.29%10.85%
Ingo Molnar150.29%21.69%
Namhyung Kim120.23%10.85%
Christoph Lameter110.21%32.54%
Corey Minyard110.21%10.85%
Christoph Hellwig90.17%10.85%
Jim Houston90.17%10.85%
Arjan van de Ven50.10%21.69%
Davide Libenzi50.10%10.85%
Arnd Bergmann30.06%10.85%
Dan Carpenter20.04%10.85%
Toyo Abe20.04%10.85%
Miroslav Lichvar20.04%10.85%
Andi Kleen20.04%10.85%
H Hartley Sweeten10.02%10.85%
Uwe Zeisberger10.02%10.85%
Paul Gortmaker10.02%10.85%
Total5233100.00%118100.00%
Directory: kernel/time
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.