time/timers: Move all time(r) related files into kernel/time

Except for Kconfig.HZ. That needs a separate treatment.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 0 insertions, 1121 deletions

diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
deleted file mode 100644
index 424c2d4..0000000
--- a/kernel/posix-timers.c
+++ /dev/null
@@ -1,1121 +0,0 @@
-/*
- * 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 <asm/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>
-
-/*
- * 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);
-
-/*
- * 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_clock posix_clocks[MAX_CLOCKS];
-
-/*
- * These ones are defined below.
- */
-static int common_nsleep(const clockid_t, int flags, struct timespec *t,
-			 struct timespec __user *rmtp);
-static int common_timer_create(struct k_itimer *new_timer);
-static void common_timer_get(struct k_itimer *, struct itimerspec *);
-static int common_timer_set(struct k_itimer *, int,
-			    struct itimerspec *, struct itimerspec *);
-static int common_timer_del(struct k_itimer *timer);
-
-static enum hrtimer_restart posix_timer_fn(struct hrtimer *data);
-
-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));
-}
-
-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;
-}
-
-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);
-}
-
-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;
-}
-
-static inline void unlock_timer(struct k_itimer *timr, unsigned long flags)
-{
-	spin_unlock_irqrestore(&timr->it_lock, flags);
-}
-
-/* Get clock_realtime */
-static int posix_clock_realtime_get(clockid_t which_clock, struct timespec *tp)
-{
-	ktime_get_real_ts(tp);
-	return 0;
-}
-
-/* Set clock_realtime */
-static int posix_clock_realtime_set(const clockid_t which_clock,
-				    const struct timespec *tp)
-{
-	return do_sys_settimeofday(tp, NULL);
-}
-
-static int posix_clock_realtime_adj(const clockid_t which_clock,
-				    struct timex *t)
-{
-	return do_adjtimex(t);
-}
-
-/*
- * Get monotonic time for posix timers
- */
-static int posix_ktime_get_ts(clockid_t which_clock, struct timespec *tp)
-{
-	ktime_get_ts(tp);
-	return 0;
-}
-
-/*
- * Get monotonic-raw time for posix timers
- */
-static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec *tp)
-{
-	getrawmonotonic(tp);
-	return 0;
-}
-
-
-static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec *tp)
-{
-	*tp = current_kernel_time();
-	return 0;
-}
-
-static int posix_get_monotonic_coarse(clockid_t which_clock,
-						struct timespec *tp)
-{
-	*tp = get_monotonic_coarse();
-	return 0;
-}
-
-static int posix_get_coarse_res(const clockid_t which_clock, struct timespec *tp)
-{
-	*tp = ktime_to_timespec(KTIME_LOW_RES);
-	return 0;
-}
-
-static int posix_get_boottime(const clockid_t which_clock, struct timespec *tp)
-{
-	get_monotonic_boottime(tp);
-	return 0;
-}
-
-static int posix_get_tai(clockid_t which_clock, struct timespec *tp)
-{
-	timekeeping_clocktai(tp);
-	return 0;
-}
-
-/*
- * Initialize everything, well, just everything in Posix clocks/timers ;)
- */
-static __init int init_posix_timers(void)
-{
-	struct k_clock clock_realtime = {
-		.clock_getres	= hrtimer_get_res,
-		.clock_get	= posix_clock_realtime_get,
-		.clock_set	= posix_clock_realtime_set,
-		.clock_adj	= posix_clock_realtime_adj,
-		.nsleep		= common_nsleep,
-		.nsleep_restart	= hrtimer_nanosleep_restart,
-		.timer_create	= common_timer_create,
-		.timer_set	= common_timer_set,
-		.timer_get	= common_timer_get,
-		.timer_del	= common_timer_del,
-	};
-	struct k_clock clock_monotonic = {
-		.clock_getres	= hrtimer_get_res,
-		.clock_get	= posix_ktime_get_ts,
-		.nsleep		= common_nsleep,
-		.nsleep_restart	= hrtimer_nanosleep_restart,
-		.timer_create	= common_timer_create,
-		.timer_set	= common_timer_set,
-		.timer_get	= common_timer_get,
-		.timer_del	= common_timer_del,
-	};
-	struct k_clock clock_monotonic_raw = {
-		.clock_getres	= hrtimer_get_res,
-		.clock_get	= posix_get_monotonic_raw,
-	};
-	struct k_clock clock_realtime_coarse = {
-		.clock_getres	= posix_get_coarse_res,
-		.clock_get	= posix_get_realtime_coarse,
-	};
-	struct k_clock clock_monotonic_coarse = {
-		.clock_getres	= posix_get_coarse_res,
-		.clock_get	= posix_get_monotonic_coarse,
-	};
-	struct k_clock clock_tai = {
-		.clock_getres	= hrtimer_get_res,
-		.clock_get	= posix_get_tai,
-		.nsleep		= common_nsleep,
-		.nsleep_restart	= hrtimer_nanosleep_restart,
-		.timer_create	= common_timer_create,
-		.timer_set	= common_timer_set,
-		.timer_get	= common_timer_get,
-		.timer_del	= common_timer_del,
-	};
-	struct k_clock clock_boottime = {
-		.clock_getres	= hrtimer_get_res,
-		.clock_get	= posix_get_boottime,
-		.nsleep		= common_nsleep,
-		.nsleep_restart	= hrtimer_nanosleep_restart,
-		.timer_create	= common_timer_create,
-		.timer_set	= common_timer_set,
-		.timer_get	= common_timer_get,
-		.timer_del	= common_timer_del,
-	};
-
-	posix_timers_register_clock(CLOCK_REALTIME, &clock_realtime);
-	posix_timers_register_clock(CLOCK_MONOTONIC, &clock_monotonic);
-	posix_timers_register_clock(CLOCK_MONOTONIC_RAW, &clock_monotonic_raw);
-	posix_timers_register_clock(CLOCK_REALTIME_COARSE, &clock_realtime_coarse);
-	posix_timers_register_clock(CLOCK_MONOTONIC_COARSE, &clock_monotonic_coarse);
-	posix_timers_register_clock(CLOCK_BOOTTIME, &clock_boottime);
-	posix_timers_register_clock(CLOCK_TAI, &clock_tai);
-
-	posix_timers_cache = kmem_cache_create("posix_timers_cache",
-					sizeof (struct k_itimer), 0, SLAB_PANIC,
-					NULL);
-	return 0;
-}
-
-__initcall(init_posix_timers);
-
-static void schedule_next_timer(struct k_itimer *timr)
-{
-	struct hrtimer *timer = &timr->it.real.timer;
-
-	if (timr->it.real.interval.tv64 == 0)
-		return;
-
-	timr->it_overrun += (unsigned int) hrtimer_forward(timer,
-						timer->base->get_time(),
-						timr->it.real.interval);
-
-	timr->it_overrun_last = timr->it_overrun;
-	timr->it_overrun = -1;
-	++timr->it_requeue_pending;
-	hrtimer_restart(timer);
-}
-
-/*
- * 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 do_schedule_next_timer(struct siginfo *info)
-{
-	struct k_itimer *timr;
-	unsigned long flags;
-
-	timr = lock_timer(info->si_tid, &flags);
-
-	if (timr && timr->it_requeue_pending == info->si_sys_private) {
-		if (timr->it_clock < 0)
-			posix_cpu_timer_schedule(timr);
-		else
-			schedule_next_timer(timr);
-
-		info->si_overrun += timr->it_overrun_last;
-	}
-
-	if (timr)
-		unlock_timer(timr, flags);
-}
-
-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()->do_schedule_next_timer().
-	 *
-	 * If dequeue_signal() sees the "right" value of
-	 * si_sys_private it calls do_schedule_next_timer().
-	 * We re-queue ->sigq and drop ->it_lock().
-	 * do_schedule_next_timer() 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;
-}
-EXPORT_SYMBOL_GPL(posix_timer_event);
-
-/*
- * 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);
-
-	if (timr->it.real.interval.tv64 != 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.real.interval.tv64 != 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 = ktime_set(0, NSEC_PER_SEC / HZ);
-
-				if (timr->it.real.interval.tv64 < kj.tv64)
-					now = ktime_add(now, kj);
-			}
-#endif
-			timr->it_overrun += (unsigned int)
-				hrtimer_forward(timer, now,
-						timr->it.real.interval);
-			ret = HRTIMER_RESTART;
-			++timr->it_requeue_pending;
-		}
-	}
-
-	unlock_timer(timr, flags);
-	return ret;
-}
-
-static struct pid *good_sigevent(sigevent_t * event)
-{
-	struct task_struct *rtn = current->group_leader;
-
-	if ((event->sigev_notify & SIGEV_THREAD_ID ) &&
-		(!(rtn = find_task_by_vpid(event->sigev_notify_thread_id)) ||
-		 !same_thread_group(rtn, current) ||
-		 (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL))
-		return NULL;
-
-	if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) &&
-	    ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX)))
-		return NULL;
-
-	return task_pid(rtn);
-}
-
-void posix_timers_register_clock(const clockid_t clock_id,
-				 struct k_clock *new_clock)
-{
-	if ((unsigned) clock_id >= MAX_CLOCKS) {
-		printk(KERN_WARNING "POSIX clock register failed for clock_id %d\n",
-		       clock_id);
-		return;
-	}
-
-	if (!new_clock->clock_get) {
-		printk(KERN_WARNING "POSIX clock id %d lacks clock_get()\n",
-		       clock_id);
-		return;
-	}
-	if (!new_clock->clock_getres) {
-		printk(KERN_WARNING "POSIX clock id %d lacks clock_getres()\n",
-		       clock_id);
-		return;
-	}
-
-	posix_clocks[clock_id] = *new_clock;
-}
-EXPORT_SYMBOL_GPL(posix_timers_register_clock);
-
-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;
-}
-
-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);
-}
-
-#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);
-}
-
-static 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 >= MAX_CLOCKS || !posix_clocks[id].clock_getres)
-		return NULL;
-	return &posix_clocks[id];
-}
-
-static int common_timer_create(struct k_itimer *new_timer)
-{
-	hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0);
-	return 0;
-}
-
-/* Create a POSIX.1b interval timer. */
-
-SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
-		struct sigevent __user *, timer_event_spec,
-		timer_t __user *, created_timer_id)
-{
-	struct k_clock *kc = clockid_to_kclock(which_clock);
-	struct k_itimer *new_timer;
-	int error, new_timer_id;
-	sigevent_t event;
-	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->it_overrun = -1;
-
-	if (timer_event_spec) {
-		if (copy_from_user(&event, timer_event_spec, sizeof (event))) {
-			error = -EFAULT;
-			goto out;
-		}
-		rcu_read_lock();
-		new_timer->it_pid = get_pid(good_sigevent(&event));
-		rcu_read_unlock();
-		if (!new_timer->it_pid) {
-			error = -EINVAL;
-			goto out;
-		}
-	} else {
-		event.sigev_notify = SIGEV_SIGNAL;
-		event.sigev_signo = SIGALRM;
-		event.sigev_value.sival_int = new_timer->it_id;
-		new_timer->it_pid = get_pid(task_tgid(current));
-	}
-
-	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;
-	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;
-}
-
-/*
- * 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;
-}
-
-/*
- * 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.
- */
-static void
-common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting)
-{
-	ktime_t now, remaining, iv;
-	struct hrtimer *timer = &timr->it.real.timer;
-
-	memset(cur_setting, 0, sizeof(struct itimerspec));
-
-	iv = timr->it.real.interval;
-
-	/* interval timer ? */
-	if (iv.tv64)
-		cur_setting->it_interval = ktime_to_timespec(iv);
-	else if (!hrtimer_active(timer) &&
-		 (timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
-		return;
-
-	now = timer->base->get_time();
-
-	/*
-	 * 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.tv64 && (timr->it_requeue_pending & REQUEUE_PENDING ||
-	    (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE))
-		timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, iv);
-
-	remaining = ktime_sub(hrtimer_get_expires(timer), now);
-	/* Return 0 only, when the timer is expired and not pending */
-	if (remaining.tv64 <= 0) {
-		/*
-		 * A single shot SIGEV_NONE timer must return 0, when
-		 * it is expired !
-		 */
-		if ((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)
-			cur_setting->it_value.tv_nsec = 1;
-	} else
-		cur_setting->it_value = ktime_to_timespec(remaining);
-}
-
-/* Get the time remaining on a POSIX.1b interval timer. */
-SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
-		struct itimerspec __user *, setting)
-{
-	struct itimerspec cur_setting;
-	struct k_itimer *timr;
-	struct k_clock *kc;
-	unsigned long flags;
-	int ret = 0;
-
-	timr = lock_timer(timer_id, &flags);
-	if (!timr)
-		return -EINVAL;
-
-	kc = clockid_to_kclock(timr->it_clock);
-	if (WARN_ON_ONCE(!kc || !kc->timer_get))
-		ret = -EINVAL;
-	else
-		kc->timer_get(timr, &cur_setting);
-
-	unlock_timer(timr, flags);
-
-	if (!ret && copy_to_user(setting, &cur_setting, sizeof (cur_setting)))
-		return -EFAULT;
-
-	return ret;
-}
-
-/*
- * 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 do_schedule_next_timer().  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;
-}
-
-/* Set a POSIX.1b interval timer. */
-/* timr->it_lock is taken. */
-static int
-common_timer_set(struct k_itimer *timr, int flags,
-		 struct itimerspec *new_setting, struct itimerspec *old_setting)
-{
-	struct hrtimer *timer = &timr->it.real.timer;
-	enum hrtimer_mode mode;
-
-	if (old_setting)
-		common_timer_get(timr, old_setting);
-
-	/* disable the timer */
-	timr->it.real.interval.tv64 = 0;
-	/*
-	 * careful here.  If smp we could be in the "fire" routine which will
-	 * be spinning as we hold the lock.  But this is ONLY an SMP issue.
-	 */
-	if (hrtimer_try_to_cancel(timer) < 0)
-		return TIMER_RETRY;
-
-	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;
-
-	mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL;
-	hrtimer_init(&timr->it.real.timer, timr->it_clock, mode);
-	timr->it.real.timer.function = posix_timer_fn;
-
-	hrtimer_set_expires(timer, timespec_to_ktime(new_setting->it_value));
-
-	/* Convert interval */
-	timr->it.real.interval = timespec_to_ktime(new_setting->it_interval);
-
-	/* SIGEV_NONE timers are not queued ! See common_timer_get */
-	if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) {
-		/* Setup correct expiry time for relative timers */
-		if (mode == HRTIMER_MODE_REL) {
-			hrtimer_add_expires(timer, timer->base->get_time());
-		}
-		return 0;
-	}
-
-	hrtimer_start_expires(timer, mode);
-	return 0;
-}
-
-/* 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 k_itimer *timr;
-	struct itimerspec new_spec, old_spec;
-	int error = 0;
-	unsigned long flag;
-	struct itimerspec *rtn = old_setting ? &old_spec : NULL;
-	struct k_clock *kc;
-
-	if (!new_setting)
-		return -EINVAL;
-
-	if (copy_from_user(&new_spec, new_setting, sizeof (new_spec)))
-		return -EFAULT;
-
-	if (!timespec_valid(&new_spec.it_interval) ||
-	    !timespec_valid(&new_spec.it_value))
-		return -EINVAL;
-retry:
-	timr = lock_timer(timer_id, &flag);
-	if (!timr)
-		return -EINVAL;
-
-	kc = clockid_to_kclock(timr->it_clock);
-	if (WARN_ON_ONCE(!kc || !kc->timer_set))
-		error = -EINVAL;
-	else
-		error = kc->timer_set(timr, flags, &new_spec, rtn);
-
-	unlock_timer(timr, flag);
-	if (error == TIMER_RETRY) {
-		rtn = NULL;	// We already got the old time...
-		goto retry;
-	}
-
-	if (old_setting && !error &&
-	    copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
-		error = -EFAULT;
-
-	return error;
-}
-
-static int common_timer_del(struct k_itimer *timer)
-{
-	timer->it.real.interval.tv64 = 0;
-
-	if (hrtimer_try_to_cancel(&timer->it.real.timer) < 0)
-		return TIMER_RETRY;
-	return 0;
-}
-
-static inline int timer_delete_hook(struct k_itimer *timer)
-{
-	struct k_clock *kc = clockid_to_kclock(timer->it_clock);
-
-	if (WARN_ON_ONCE(!kc || !kc->timer_del))
-		return -EINVAL;
-	return kc->timer_del(timer);
-}
-
-/* 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);
-}
-
-/*
- * 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);
-	}
-}
-
-SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
-		const struct timespec __user *, tp)
-{
-	struct k_clock *kc = clockid_to_kclock(which_clock);
-	struct timespec new_tp;
-
-	if (!kc || !kc->clock_set)
-		return -EINVAL;
-
-	if (copy_from_user(&new_tp, tp, sizeof (*tp)))
-		return -EFAULT;
-
-	return kc->clock_set(which_clock, &new_tp);
-}
-
-SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
-		struct timespec __user *,tp)
-{
-	struct k_clock *kc = clockid_to_kclock(which_clock);
-	struct timespec kernel_tp;
-	int error;
-
-	if (!kc)
-		return -EINVAL;
-
-	error = kc->clock_get(which_clock, &kernel_tp);
-
-	if (!error && copy_to_user(tp, &kernel_tp, sizeof (kernel_tp)))
-		error = -EFAULT;
-
-	return error;
-}
-
-SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock,
-		struct timex __user *, utx)
-{
-	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)
-{
-	struct k_clock *kc = clockid_to_kclock(which_clock);
-	struct timespec rtn_tp;
-	int error;
-
-	if (!kc)
-		return -EINVAL;
-
-	error = kc->clock_getres(which_clock, &rtn_tp);
-
-	if (!error && tp && copy_to_user(tp, &rtn_tp, sizeof (rtn_tp)))
-		error = -EFAULT;
-
-	return error;
-}
-
-/*
- * nanosleep for monotonic and realtime clocks
- */
-static int common_nsleep(const clockid_t which_clock, int flags,
-			 struct timespec *tsave, struct timespec __user *rmtp)
-{
-	return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ?
-				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
-				 which_clock);
-}
-
-SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
-		const struct timespec __user *, rqtp,
-		struct timespec __user *, rmtp)
-{
-	struct k_clock *kc = clockid_to_kclock(which_clock);
-	struct timespec t;
-
-	if (!kc)
-		return -EINVAL;
-	if (!kc->nsleep)
-		return -ENANOSLEEP_NOTSUP;
-
-	if (copy_from_user(&t, rqtp, sizeof (struct timespec)))
-		return -EFAULT;
-
-	if (!timespec_valid(&t))
-		return -EINVAL;
-
-	return kc->nsleep(which_clock, flags, &t, rmtp);
-}
-
-/*
- * This will restart clock_nanosleep. This is required only by
- * compat_clock_nanosleep_restart for now.
- */
-long clock_nanosleep_restart(struct restart_block *restart_block)
-{
-	clockid_t which_clock = restart_block->nanosleep.clockid;
-	struct k_clock *kc = clockid_to_kclock(which_clock);
-
-	if (WARN_ON_ONCE(!kc || !kc->nsleep_restart))
-		return -EINVAL;
-
-	return kc->nsleep_restart(restart_block);
-}