mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 16:29:59 +00:00
![Thomas Gleixner](/assets/img/avatar_default.png)
Remove the unused variable *node introduced by commit 5ed67f05
(posix
timers: Allocate timer id per process)
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Pavel Emelyanov <xemul@parallels.com>
1121 lines
30 KiB
C
1121 lines
30 KiB
C
/*
|
|
* 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(¤t->sighand->siglock);
|
|
new_timer->it_signal = current->signal;
|
|
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;
|
|
|
|
/*
|
|
* 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(¤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).
|
|
*/
|
|
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);
|
|
}
|