| /* |
| * 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 <asm/semaphore.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; |
| } |
| |
| /* |
| * 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; |
| } |
| |
| /* |
| * 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, |
| }; |
| |
| register_posix_clock(CLOCK_REALTIME, &clock_realtime); |
| register_posix_clock(CLOCK_MONOTONIC, &clock_monotonic); |
| |
| posix_timers_cache = kmem_cache_create("posix_timers_cache", |
| sizeof (struct k_itimer), 0, 0, 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 += 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) |
| { |
| memset(&timr->sigq->info, 0, sizeof(siginfo_t)); |
| timr->sigq->info.si_sys_private = si_private; |
| /* Send signal to the process that owns this timer.*/ |
| |
| timr->sigq->info.si_signo = timr->it_sigev_signo; |
| timr->sigq->info.si_errno = 0; |
| timr->sigq->info.si_code = SI_TIMER; |
| timr->sigq->info.si_tid = timr->it_id; |
| timr->sigq->info.si_value = timr->it_sigev_value; |
| |
| if (timr->it_sigev_notify & SIGEV_THREAD_ID) { |
| struct task_struct *leader; |
| int ret = send_sigqueue(timr->it_sigev_signo, timr->sigq, |
| timr->it_process); |
| |
| if (likely(ret >= 0)) |
| return ret; |
| |
| timr->it_sigev_notify = SIGEV_SIGNAL; |
| leader = timr->it_process->group_leader; |
| put_task_struct(timr->it_process); |
| timr->it_process = leader; |
| } |
| |
| return send_group_sigqueue(timr->it_sigev_signo, timr->sigq, |
| timr->it_process); |
| } |
| 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 += |
| 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_pid(event->sigev_notify_thread_id)) || |
| rtn->tgid != current->tgid || |
| (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); |
| tmr = NULL; |
| } |
| 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); |
| if (unlikely(tmr->it_process) && |
| tmr->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) |
| put_task_struct(tmr->it_process); |
| kmem_cache_free(posix_timers_cache, tmr); |
| } |
| |
| /* Create a POSIX.1b interval timer. */ |
| |
| asmlinkage long |
| sys_timer_create(const clockid_t which_clock, |
| struct sigevent __user *timer_event_spec, |
| timer_t __user * created_timer_id) |
| { |
| int error = 0; |
| struct k_itimer *new_timer = NULL; |
| int new_timer_id; |
| struct task_struct *process = NULL; |
| unsigned long flags; |
| 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, (void *) new_timer, |
| &new_timer_id); |
| spin_unlock_irq(&idr_lock); |
| if (error == -EAGAIN) |
| goto retry; |
| else if (error) { |
| /* |
| * Wierd 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; |
| } |
| new_timer->it_sigev_notify = event.sigev_notify; |
| new_timer->it_sigev_signo = event.sigev_signo; |
| new_timer->it_sigev_value = event.sigev_value; |
| |
| read_lock(&tasklist_lock); |
| if ((process = good_sigevent(&event))) { |
| /* |
| * We may be setting up this process for another |
| * thread. It may be exiting. To catch this |
| * case the we check the PF_EXITING flag. If |
| * the flag is not set, the siglock will catch |
| * him before it is too late (in exit_itimers). |
| * |
| * The exec case is a bit more invloved but easy |
| * to code. If the process is in our thread |
| * group (and it must be or we would not allow |
| * it here) and is doing an exec, it will cause |
| * us to be killed. In this case it will wait |
| * for us to die which means we can finish this |
| * linkage with our last gasp. I.e. no code :) |
| */ |
| spin_lock_irqsave(&process->sighand->siglock, flags); |
| if (!(process->flags & PF_EXITING)) { |
| new_timer->it_process = process; |
| list_add(&new_timer->list, |
| &process->signal->posix_timers); |
| if (new_timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) |
| get_task_struct(process); |
| spin_unlock_irqrestore(&process->sighand->siglock, flags); |
| } else { |
| spin_unlock_irqrestore(&process->sighand->siglock, flags); |
| process = NULL; |
| } |
| } |
| read_unlock(&tasklist_lock); |
| if (!process) { |
| error = -EINVAL; |
| goto out; |
| } |
| } else { |
| new_timer->it_sigev_notify = SIGEV_SIGNAL; |
| new_timer->it_sigev_signo = SIGALRM; |
| new_timer->it_sigev_value.sival_int = new_timer->it_id; |
| process = current->group_leader; |
| spin_lock_irqsave(&process->sighand->siglock, flags); |
| new_timer->it_process = process; |
| list_add(&new_timer->list, &process->signal->posix_timers); |
| spin_unlock_irqrestore(&process->sighand->siglock, flags); |
| } |
| |
| /* |
| * 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: |
| if (error) |
| 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 = (struct k_itimer *) idr_find(&posix_timers_id, (int) timer_id); |
| if (timr) { |
| spin_lock(&timr->it_lock); |
| |
| if ((timr->it_id != timer_id) || !(timr->it_process) || |
| timr->it_process->tgid != current->tgid) { |
| spin_unlock(&timr->it_lock); |
| spin_unlock_irqrestore(&idr_lock, *flags); |
| timr = NULL; |
| } else |
| spin_unlock(&idr_lock); |
| } else |
| spin_unlock_irqrestore(&idr_lock, *flags); |
| |
| return timr; |
| } |
| |
| /* |
| * 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 += hrtimer_forward(timer, now, iv); |
| |
| remaining = ktime_sub(timer->expires, 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. */ |
| asmlinkage long |
| sys_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. |
| */ |
| asmlinkage long |
| sys_timer_getoverrun(timer_t timer_id) |
| { |
| struct k_itimer *timr; |
| int overrun; |
| 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; |
| |
| timer->expires = 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) |
| timer->expires = ktime_add(timer->expires, |
| timer->base->get_time()); |
| return 0; |
| } |
| |
| hrtimer_start(timer, timer->expires, mode); |
| return 0; |
| } |
| |
| /* Set a POSIX.1b interval timer */ |
| asmlinkage long |
| sys_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; |
| 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. */ |
| asmlinkage long |
| sys_timer_delete(timer_t timer_id) |
| { |
| struct k_itimer *timer; |
| 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). |
| */ |
| if (timer->it_process) { |
| if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) |
| 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). |
| */ |
| if (timer->it_process) { |
| if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) |
| 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); |
| |
| asmlinkage long sys_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)); |
| } |
| |
| asmlinkage long |
| sys_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; |
| |
| } |
| |
| asmlinkage long |
| sys_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); |
| } |
| |
| asmlinkage long |
| sys_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)); |
| } |