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Diffstat (limited to 'kernel/posix-timers.c')
| -rw-r--r-- | kernel/posix-timers.c | 1000 |
1 files changed, 1000 insertions, 0 deletions
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c new file mode 100644 index 0000000..6c48fc8 --- /dev/null +++ b/kernel/posix-timers.c @@ -0,0 +1,1000 @@ +/* + * 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/idr.h> +#include <linux/posix-timers.h> +#include <linux/syscalls.h> +#include <linux/wait.h> +#include <linux/workqueue.h> +#include <linux/module.h> + +/* + * Management arrays for POSIX timers. Timers are kept in slab memory + * Timer ids are allocated by an external routine that keeps track of the + * id and the timer. The external interface is: + * + * void *idr_find(struct idr *idp, int id); to find timer_id <id> + * int idr_get_new(struct idr *idp, void *ptr); to get a new id and + * related it to <ptr> + * void idr_remove(struct idr *idp, int id); to release <id> + * void idr_init(struct idr *idp); to initialize <idp> + * which we supply. + * The idr_get_new *may* call slab for more memory so it must not be + * called under a spin lock. Likewise idr_remore may release memory + * (but it may be ok to do this under a lock...). + * idr_find is just a memory look up and is quite fast. A -1 return + * indicates that the requested id does not exist. + */ + +/* + * Lets keep our timers in a slab cache :-) + */ +static struct kmem_cache *posix_timers_cache; +static struct idr posix_timers_id; +static DEFINE_SPINLOCK(idr_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 + + +/* + * 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 and allows the possibility of adding others. We + * provide an interface to add clocks to the table and expect + * the "arch" code to add at least one clock that is high + * resolution. Here we define the standard CLOCK_REALTIME as a + * 1/HZ resolution clock. + * + * 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. For clocks that use the standard + * system timer code these entries should be NULL. This will + * allow dispatch without the overhead of indirect function + * calls. CLOCKS that depend on other sources (e.g. WWV or GPS) + * must supply functions here, even if the function just returns + * ENOSYS. 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_process + * fields are not modified by timer code. + * + * At this time all functions EXCEPT clock_nanosleep can be + * redirected by the CLOCKS structure. Clock_nanosleep is in + * there, but the code ignores it. + * + * 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 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); + +static inline void unlock_timer(struct k_itimer *timr, unsigned long flags) +{ + spin_unlock_irqrestore(&timr->it_lock, flags); +} + +/* + * Call the k_clock hook function if non-null, or the default function. + */ +#define CLOCK_DISPATCH(clock, call, arglist) \ + ((clock) < 0 ? posix_cpu_##call arglist : \ + (posix_clocks[clock].call != NULL \ + ? (*posix_clocks[clock].call) arglist : common_##call arglist)) + +/* + * Default clock hook functions when the struct k_clock passed + * to register_posix_clock leaves a function pointer null. + * + * The function common_CALL is the default implementation for + * the function pointer CALL in struct k_clock. + */ + +static inline int common_clock_getres(const clockid_t which_clock, + struct timespec *tp) +{ + tp->tv_sec = 0; + tp->tv_nsec = posix_clocks[which_clock].res; + return 0; +} + +/* + * Get real time for posix timers + */ +static int common_clock_get(clockid_t which_clock, struct timespec *tp) +{ + ktime_get_real_ts(tp); + return 0; +} + +static inline int common_clock_set(const clockid_t which_clock, + struct timespec *tp) +{ + return do_sys_settimeofday(tp, NULL); +} + +static int common_timer_create(struct k_itimer *new_timer) +{ + hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0); + return 0; +} + +static int no_timer_create(struct k_itimer *new_timer) +{ + return -EOPNOTSUPP; +} + +/* + * Return nonzero if we know a priori this clockid_t value is bogus. + */ +static inline int invalid_clockid(const clockid_t which_clock) +{ + if (which_clock < 0) /* CPU clock, posix_cpu_* will check it */ + return 0; + if ((unsigned) which_clock >= MAX_CLOCKS) + return 1; + if (posix_clocks[which_clock].clock_getres != NULL) + return 0; + if (posix_clocks[which_clock].res != 0) + return 0; + return 1; +} + +/* + * 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 time for posix timers + */ +static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec *tp) +{ + getrawmonotonic(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, + }; + struct k_clock clock_monotonic = { + .clock_getres = hrtimer_get_res, + .clock_get = posix_ktime_get_ts, + .clock_set = do_posix_clock_nosettime, + }; + struct k_clock clock_monotonic_raw = { + .clock_getres = hrtimer_get_res, + .clock_get = posix_get_monotonic_raw, + .clock_set = do_posix_clock_nosettime, + .timer_create = no_timer_create, + }; + + register_posix_clock(CLOCK_REALTIME, &clock_realtime); + register_posix_clock(CLOCK_MONOTONIC, &clock_monotonic); + register_posix_clock(CLOCK_MONOTONIC_RAW, &clock_monotonic_raw); + + posix_timers_cache = kmem_cache_create("posix_timers_cache", + sizeof (struct k_itimer), 0, SLAB_PANIC, + NULL); + idr_init(&posix_timers_id); + 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 aginst 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) +{ + int shared, ret; + /* + * 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; + + shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID); + ret = send_sigqueue(timr->sigq, timr->it_process, shared); + /* 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 task_struct * 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 rtn; +} + +void register_posix_clock(const clockid_t clock_id, struct k_clock *new_clock) +{ + if ((unsigned) clock_id >= MAX_CLOCKS) { + printk("POSIX clock register failed for clock_id %d\n", + clock_id); + return; + } + + posix_clocks[clock_id] = *new_clock; +} +EXPORT_SYMBOL_GPL(register_posix_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; +} + +#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(&idr_lock, flags); + idr_remove(&posix_timers_id, tmr->it_id); + spin_unlock_irqrestore(&idr_lock, flags); + } + sigqueue_free(tmr->sigq); + kmem_cache_free(posix_timers_cache, tmr); +} + +/* 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_itimer *new_timer; + int error, new_timer_id; + struct task_struct *process; + sigevent_t event; + int it_id_set = IT_ID_NOT_SET; + + if (invalid_clockid(which_clock)) + return -EINVAL; + + new_timer = alloc_posix_timer(); + if (unlikely(!new_timer)) + return -EAGAIN; + + spin_lock_init(&new_timer->it_lock); + retry: + if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) { + error = -EAGAIN; + goto out; + } + spin_lock_irq(&idr_lock); + error = idr_get_new(&posix_timers_id, new_timer, &new_timer_id); + spin_unlock_irq(&idr_lock); + if (error) { + if (error == -EAGAIN) + goto retry; + /* + * Weird looking, but we return EAGAIN if the IDR is + * full (proper POSIX return value for this) + */ + error = -EAGAIN; + 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; + error = CLOCK_DISPATCH(which_clock, timer_create, (new_timer)); + if (error) + goto out; + + /* + * return the timer_id now. The next step is hard to + * back out if there is an error. + */ + if (copy_to_user(created_timer_id, + &new_timer_id, sizeof (new_timer_id))) { + error = -EFAULT; + goto out; + } + if (timer_event_spec) { + if (copy_from_user(&event, timer_event_spec, sizeof (event))) { + error = -EFAULT; + goto out; + } + rcu_read_lock(); + process = good_sigevent(&event); + if (process) + get_task_struct(process); + rcu_read_unlock(); + if (!process) { + error = -EINVAL; + goto out; + } + } else { + event.sigev_notify = SIGEV_SIGNAL; + event.sigev_signo = SIGALRM; + event.sigev_value.sival_int = new_timer->it_id; + process = current->group_leader; + get_task_struct(process); + } + + 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; + + spin_lock_irq(¤t->sighand->siglock); + new_timer->it_process = process; + list_add(&new_timer->list, ¤t->signal->posix_timers); + spin_unlock_irq(¤t->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; + /* + * Watch out here. We do a irqsave on the idr_lock and pass the + * flags part over to the timer lock. Must not let interrupts in + * while we are moving the lock. + */ + spin_lock_irqsave(&idr_lock, *flags); + timr = idr_find(&posix_timers_id, (int)timer_id); + if (timr) { + spin_lock(&timr->it_lock); + if (timr->it_process && + same_thread_group(timr->it_process, current)) { + spin_unlock(&idr_lock); + return timr; + } + spin_unlock(&timr->it_lock); + } + spin_unlock_irqrestore(&idr_lock, *flags); + + 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 k_itimer *timr; + struct itimerspec cur_setting; + unsigned long flags; + + timr = lock_timer(timer_id, &flags); + if (!timr) + return -EINVAL; + + CLOCK_DISPATCH(timr->it_clock, timer_get, (timr, &cur_setting)); + + unlock_timer(timr, flags); + + if (copy_to_user(setting, &cur_setting, sizeof (cur_setting))) + return -EFAULT; + + return 0; +} + +/* + * 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; + + 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; + + error = CLOCK_DISPATCH(timr->it_clock, 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 inline 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) +{ + return CLOCK_DISPATCH(timer->it_clock, 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(¤t->sighand->siglock); + list_del(&timer->list); + spin_unlock(¤t->sighand->siglock); + /* + * This keeps any tasks waiting on the spin lock from thinking + * they got something (see the lock code above). + */ + put_task_struct(timer->it_process); + timer->it_process = 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). + */ + put_task_struct(timer->it_process); + timer->it_process = 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); + } +} + +/* Not available / possible... functions */ +int do_posix_clock_nosettime(const clockid_t clockid, struct timespec *tp) +{ + return -EINVAL; +} +EXPORT_SYMBOL_GPL(do_posix_clock_nosettime); + +int do_posix_clock_nonanosleep(const clockid_t clock, int flags, + struct timespec *t, struct timespec __user *r) +{ +#ifndef ENOTSUP + return -EOPNOTSUPP; /* aka ENOTSUP in userland for POSIX */ +#else /* parisc does define it separately. */ + return -ENOTSUP; +#endif +} +EXPORT_SYMBOL_GPL(do_posix_clock_nonanosleep); + +SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock, + const struct timespec __user *, tp) +{ + struct timespec new_tp; + + if (invalid_clockid(which_clock)) + return -EINVAL; + if (copy_from_user(&new_tp, tp, sizeof (*tp))) + return -EFAULT; + + return CLOCK_DISPATCH(which_clock, clock_set, (which_clock, &new_tp)); +} + +SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock, + struct timespec __user *,tp) +{ + struct timespec kernel_tp; + int error; + + if (invalid_clockid(which_clock)) + return -EINVAL; + error = CLOCK_DISPATCH(which_clock, clock_get, + (which_clock, &kernel_tp)); + if (!error && copy_to_user(tp, &kernel_tp, sizeof (kernel_tp))) + error = -EFAULT; + + return error; + +} + +SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock, + struct timespec __user *, tp) +{ + struct timespec rtn_tp; + int error; + + if (invalid_clockid(which_clock)) + return -EINVAL; + + error = CLOCK_DISPATCH(which_clock, 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 timespec t; + + if (invalid_clockid(which_clock)) + return -EINVAL; + + if (copy_from_user(&t, rqtp, sizeof (struct timespec))) + return -EFAULT; + + if (!timespec_valid(&t)) + return -EINVAL; + + return CLOCK_DISPATCH(which_clock, nsleep, + (which_clock, flags, &t, rmtp)); +} + +/* + * nanosleep_restart for monotonic and realtime clocks + */ +static int common_nsleep_restart(struct restart_block *restart_block) +{ + return hrtimer_nanosleep_restart(restart_block); +} + +/* + * 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->arg0; + + return CLOCK_DISPATCH(which_clock, nsleep_restart, + (restart_block)); +} |
