diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /kernel/posix-timers.c |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'kernel/posix-timers.c')
-rw-r--r-- | kernel/posix-timers.c | 1584 |
1 files changed, 1584 insertions, 0 deletions
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c new file mode 100644 index 00000000000..fd316c27226 --- /dev/null +++ b/kernel/posix-timers.c @@ -0,0 +1,1584 @@ +/* + * 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/smp_lock.h> +#include <linux/interrupt.h> +#include <linux/slab.h> +#include <linux/time.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> + +#ifndef div_long_long_rem +#include <asm/div64.h> + +#define div_long_long_rem(dividend,divisor,remainder) ({ \ + u64 result = dividend; \ + *remainder = do_div(result,divisor); \ + result; }) + +#endif +#define CLOCK_REALTIME_RES TICK_NSEC /* In nano seconds. */ + +static inline u64 mpy_l_X_l_ll(unsigned long mpy1,unsigned long mpy2) +{ + return (u64)mpy1 * mpy2; +} +/* + * 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 kmem_cache_t *posix_timers_cache; +static struct idr posix_timers_id; +static DEFINE_SPINLOCK(idr_lock); + +/* + * Just because the timer is not in the timer list does NOT mean it is + * inactive. It could be in the "fire" routine getting a new expire time. + */ +#define TIMER_INACTIVE 1 + +#ifdef CONFIG_SMP +# define timer_active(tmr) \ + ((tmr)->it.real.timer.entry.prev != (void *)TIMER_INACTIVE) +# define set_timer_inactive(tmr) \ + do { \ + (tmr)->it.real.timer.entry.prev = (void *)TIMER_INACTIVE; \ + } while (0) +#else +# define timer_active(tmr) BARFY // error to use outside of SMP +# define set_timer_inactive(tmr) do { } while (0) +#endif +/* + * 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]; +/* + * We only have one real clock that can be set so we need only one abs list, + * even if we should want to have several clocks with differing resolutions. + */ +static struct k_clock_abs abs_list = {.list = LIST_HEAD_INIT(abs_list.list), + .lock = SPIN_LOCK_UNLOCKED}; + +static void posix_timer_fn(unsigned long); +static u64 do_posix_clock_monotonic_gettime_parts( + struct timespec *tp, struct timespec *mo); +int do_posix_clock_monotonic_gettime(struct timespec *tp); +static int do_posix_clock_monotonic_get(clockid_t, struct timespec *tp); + +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(clockid_t which_clock, + struct timespec *tp) +{ + tp->tv_sec = 0; + tp->tv_nsec = posix_clocks[which_clock].res; + return 0; +} + +static inline int common_clock_get(clockid_t which_clock, struct timespec *tp) +{ + getnstimeofday(tp); + return 0; +} + +static inline int common_clock_set(clockid_t which_clock, struct timespec *tp) +{ + return do_sys_settimeofday(tp, NULL); +} + +static inline int common_timer_create(struct k_itimer *new_timer) +{ + INIT_LIST_HEAD(&new_timer->it.real.abs_timer_entry); + init_timer(&new_timer->it.real.timer); + new_timer->it.real.timer.data = (unsigned long) new_timer; + new_timer->it.real.timer.function = posix_timer_fn; + set_timer_inactive(new_timer); + return 0; +} + +/* + * These ones are defined below. + */ +static int common_nsleep(clockid_t, int flags, struct timespec *t); +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); + +/* + * Return nonzero iff we know a priori this clockid_t value is bogus. + */ +static inline int invalid_clockid(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; +#ifndef CLOCK_DISPATCH_DIRECT + if (posix_clocks[which_clock].res != 0) + return 0; +#endif + return 1; +} + + +/* + * Initialize everything, well, just everything in Posix clocks/timers ;) + */ +static __init int init_posix_timers(void) +{ + struct k_clock clock_realtime = {.res = CLOCK_REALTIME_RES, + .abs_struct = &abs_list + }; + struct k_clock clock_monotonic = {.res = CLOCK_REALTIME_RES, + .abs_struct = NULL, + .clock_get = do_posix_clock_monotonic_get, + .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, NULL); + idr_init(&posix_timers_id); + return 0; +} + +__initcall(init_posix_timers); + +static void tstojiffie(struct timespec *tp, int res, u64 *jiff) +{ + long sec = tp->tv_sec; + long nsec = tp->tv_nsec + res - 1; + + if (nsec > NSEC_PER_SEC) { + sec++; + nsec -= NSEC_PER_SEC; + } + + /* + * The scaling constants are defined in <linux/time.h> + * The difference between there and here is that we do the + * res rounding and compute a 64-bit result (well so does that + * but it then throws away the high bits). + */ + *jiff = (mpy_l_X_l_ll(sec, SEC_CONVERSION) + + (mpy_l_X_l_ll(nsec, NSEC_CONVERSION) >> + (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC; +} + +/* + * This function adjusts the timer as needed as a result of the clock + * being set. It should only be called for absolute timers, and then + * under the abs_list lock. It computes the time difference and sets + * the new jiffies value in the timer. It also updates the timers + * reference wall_to_monotonic value. It is complicated by the fact + * that tstojiffies() only handles positive times and it needs to work + * with both positive and negative times. Also, for negative offsets, + * we need to defeat the res round up. + * + * Return is true if there is a new time, else false. + */ +static long add_clockset_delta(struct k_itimer *timr, + struct timespec *new_wall_to) +{ + struct timespec delta; + int sign = 0; + u64 exp; + + set_normalized_timespec(&delta, + new_wall_to->tv_sec - + timr->it.real.wall_to_prev.tv_sec, + new_wall_to->tv_nsec - + timr->it.real.wall_to_prev.tv_nsec); + if (likely(!(delta.tv_sec | delta.tv_nsec))) + return 0; + if (delta.tv_sec < 0) { + set_normalized_timespec(&delta, + -delta.tv_sec, + 1 - delta.tv_nsec - + posix_clocks[timr->it_clock].res); + sign++; + } + tstojiffie(&delta, posix_clocks[timr->it_clock].res, &exp); + timr->it.real.wall_to_prev = *new_wall_to; + timr->it.real.timer.expires += (sign ? -exp : exp); + return 1; +} + +static void remove_from_abslist(struct k_itimer *timr) +{ + if (!list_empty(&timr->it.real.abs_timer_entry)) { + spin_lock(&abs_list.lock); + list_del_init(&timr->it.real.abs_timer_entry); + spin_unlock(&abs_list.lock); + } +} + +static void schedule_next_timer(struct k_itimer *timr) +{ + struct timespec new_wall_to; + struct now_struct now; + unsigned long seq; + + /* + * Set up the timer for the next interval (if there is one). + * Note: this code uses the abs_timer_lock to protect + * it.real.wall_to_prev and must hold it until exp is set, not exactly + * obvious... + + * This function is used for CLOCK_REALTIME* and + * CLOCK_MONOTONIC* timers. If we ever want to handle other + * CLOCKs, the calling code (do_schedule_next_timer) would need + * to pull the "clock" info from the timer and dispatch the + * "other" CLOCKs "next timer" code (which, I suppose should + * also be added to the k_clock structure). + */ + if (!timr->it.real.incr) + return; + + do { + seq = read_seqbegin(&xtime_lock); + new_wall_to = wall_to_monotonic; + posix_get_now(&now); + } while (read_seqretry(&xtime_lock, seq)); + + if (!list_empty(&timr->it.real.abs_timer_entry)) { + spin_lock(&abs_list.lock); + add_clockset_delta(timr, &new_wall_to); + + posix_bump_timer(timr, now); + + spin_unlock(&abs_list.lock); + } else { + posix_bump_timer(timr, now); + } + timr->it_overrun_last = timr->it_overrun; + timr->it_overrun = -1; + ++timr->it_requeue_pending; + add_timer(&timr->it.real.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) + goto exit; + + if (timr->it_clock < 0) /* CPU clock */ + posix_cpu_timer_schedule(timr); + else + schedule_next_timer(timr); + info->si_overrun = timr->it_overrun_last; +exit: + 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. + + * This code assumes that all the possible abs_lists share the + * same lock (there is only one list at this time). If this is + * not the case, the CLOCK info would need to be used to find + * the proper abs list lock. + */ + + 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) { + if (unlikely(timr->it_process->flags & PF_EXITING)) { + timr->it_sigev_notify = SIGEV_SIGNAL; + put_task_struct(timr->it_process); + timr->it_process = timr->it_process->group_leader; + goto group; + } + return send_sigqueue(timr->it_sigev_signo, timr->sigq, + timr->it_process); + } + else { + group: + 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 void posix_timer_fn(unsigned long __data) +{ + struct k_itimer *timr = (struct k_itimer *) __data; + unsigned long flags; + unsigned long seq; + struct timespec delta, new_wall_to; + u64 exp = 0; + int do_notify = 1; + + spin_lock_irqsave(&timr->it_lock, flags); + set_timer_inactive(timr); + if (!list_empty(&timr->it.real.abs_timer_entry)) { + spin_lock(&abs_list.lock); + do { + seq = read_seqbegin(&xtime_lock); + new_wall_to = wall_to_monotonic; + } while (read_seqretry(&xtime_lock, seq)); + set_normalized_timespec(&delta, + new_wall_to.tv_sec - + timr->it.real.wall_to_prev.tv_sec, + new_wall_to.tv_nsec - + timr->it.real.wall_to_prev.tv_nsec); + if (likely((delta.tv_sec | delta.tv_nsec ) == 0)) { + /* do nothing, timer is on time */ + } else if (delta.tv_sec < 0) { + /* do nothing, timer is already late */ + } else { + /* timer is early due to a clock set */ + tstojiffie(&delta, + posix_clocks[timr->it_clock].res, + &exp); + timr->it.real.wall_to_prev = new_wall_to; + timr->it.real.timer.expires += exp; + add_timer(&timr->it.real.timer); + do_notify = 0; + } + spin_unlock(&abs_list.lock); + + } + if (do_notify) { + int si_private=0; + + if (timr->it.real.incr) + si_private = ++timr->it_requeue_pending; + else { + remove_from_abslist(timr); + } + + 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. + */ + schedule_next_timer(timr); + } + unlock_timer(timr, flags); /* hold thru abs lock to keep irq off */ +} + + +static inline 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(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_alloc(posix_timers_cache, GFP_KERNEL); + if (!tmr) + return tmr; + memset(tmr, 0, sizeof (struct k_itimer)); + 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(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); + spin_unlock_irqrestore(&process->sighand->siglock, flags); + if (new_timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) + get_task_struct(process); + } 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; +} + +/* + * good_timespec + * + * This function checks the elements of a timespec structure. + * + * Arguments: + * ts : Pointer to the timespec structure to check + * + * Return value: + * If a NULL pointer was passed in, or the tv_nsec field was less than 0 + * or greater than NSEC_PER_SEC, or the tv_sec field was less than 0, + * this function returns 0. Otherwise it returns 1. + */ +static int good_timespec(const struct timespec *ts) +{ + if ((!ts) || (ts->tv_sec < 0) || + ((unsigned) ts->tv_nsec >= NSEC_PER_SEC)) + return 0; + return 1; +} + +/* + * 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); + spin_unlock(&idr_lock); + + if ((timr->it_id != timer_id) || !(timr->it_process) || + timr->it_process->tgid != current->tgid) { + unlock_timer(timr, *flags); + timr = NULL; + } + } 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) +{ + unsigned long expires; + struct now_struct now; + + do + expires = timr->it.real.timer.expires; + while ((volatile long) (timr->it.real.timer.expires) != expires); + + posix_get_now(&now); + + if (expires && + ((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) && + !timr->it.real.incr && + posix_time_before(&timr->it.real.timer, &now)) + timr->it.real.timer.expires = expires = 0; + if (expires) { + if (timr->it_requeue_pending & REQUEUE_PENDING || + (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) { + posix_bump_timer(timr, now); + expires = timr->it.real.timer.expires; + } + else + if (!timer_pending(&timr->it.real.timer)) + expires = 0; + if (expires) + expires -= now.jiffies; + } + jiffies_to_timespec(expires, &cur_setting->it_value); + jiffies_to_timespec(timr->it.real.incr, &cur_setting->it_interval); + + if (cur_setting->it_value.tv_sec < 0) { + cur_setting->it_value.tv_nsec = 1; + cur_setting->it_value.tv_sec = 0; + } +} + +/* 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; +} +/* + * Adjust for absolute time + * + * If absolute time is given and it is not CLOCK_MONOTONIC, we need to + * adjust for the offset between the timer clock (CLOCK_MONOTONIC) and + * what ever clock he is using. + * + * If it is relative time, we need to add the current (CLOCK_MONOTONIC) + * time to it to get the proper time for the timer. + */ +static int adjust_abs_time(struct k_clock *clock, struct timespec *tp, + int abs, u64 *exp, struct timespec *wall_to) +{ + struct timespec now; + struct timespec oc = *tp; + u64 jiffies_64_f; + int rtn =0; + + if (abs) { + /* + * The mask pick up the 4 basic clocks + */ + if (!((clock - &posix_clocks[0]) & ~CLOCKS_MASK)) { + jiffies_64_f = do_posix_clock_monotonic_gettime_parts( + &now, wall_to); + /* + * If we are doing a MONOTONIC clock + */ + if((clock - &posix_clocks[0]) & CLOCKS_MONO){ + now.tv_sec += wall_to->tv_sec; + now.tv_nsec += wall_to->tv_nsec; + } + } else { + /* + * Not one of the basic clocks + */ + clock->clock_get(clock - posix_clocks, &now); + jiffies_64_f = get_jiffies_64(); + } + /* + * Take away now to get delta + */ + oc.tv_sec -= now.tv_sec; + oc.tv_nsec -= now.tv_nsec; + /* + * Normalize... + */ + while ((oc.tv_nsec - NSEC_PER_SEC) >= 0) { + oc.tv_nsec -= NSEC_PER_SEC; + oc.tv_sec++; + } + while ((oc.tv_nsec) < 0) { + oc.tv_nsec += NSEC_PER_SEC; + oc.tv_sec--; + } + }else{ + jiffies_64_f = get_jiffies_64(); + } + /* + * Check if the requested time is prior to now (if so set now) + */ + if (oc.tv_sec < 0) + oc.tv_sec = oc.tv_nsec = 0; + + if (oc.tv_sec | oc.tv_nsec) + set_normalized_timespec(&oc, oc.tv_sec, + oc.tv_nsec + clock->res); + tstojiffie(&oc, clock->res, exp); + + /* + * Check if the requested time is more than the timer code + * can handle (if so we error out but return the value too). + */ + if (*exp > ((u64)MAX_JIFFY_OFFSET)) + /* + * This is a considered response, not exactly in + * line with the standard (in fact it is silent on + * possible overflows). We assume such a large + * value is ALMOST always a programming error and + * try not to compound it by setting a really dumb + * value. + */ + rtn = -EINVAL; + /* + * return the actual jiffies expire time, full 64 bits + */ + *exp += jiffies_64_f; + return rtn; +} + +/* Set a POSIX.1b interval timer. */ +/* timr->it_lock is taken. */ +static inline int +common_timer_set(struct k_itimer *timr, int flags, + struct itimerspec *new_setting, struct itimerspec *old_setting) +{ + struct k_clock *clock = &posix_clocks[timr->it_clock]; + u64 expire_64; + + if (old_setting) + common_timer_get(timr, old_setting); + + /* disable the timer */ + timr->it.real.incr = 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. + */ +#ifdef CONFIG_SMP + if (timer_active(timr) && !del_timer(&timr->it.real.timer)) + /* + * It can only be active if on an other cpu. Since + * we have cleared the interval stuff above, it should + * clear once we release the spin lock. Of course once + * we do that anything could happen, including the + * complete melt down of the timer. So return with + * a "retry" exit status. + */ + return TIMER_RETRY; + + set_timer_inactive(timr); +#else + del_timer(&timr->it.real.timer); +#endif + remove_from_abslist(timr); + + timr->it_requeue_pending = (timr->it_requeue_pending + 2) & + ~REQUEUE_PENDING; + timr->it_overrun_last = 0; + timr->it_overrun = -1; + /* + *switch off the timer when it_value is zero + */ + if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec) { + timr->it.real.timer.expires = 0; + return 0; + } + + if (adjust_abs_time(clock, + &new_setting->it_value, flags & TIMER_ABSTIME, + &expire_64, &(timr->it.real.wall_to_prev))) { + return -EINVAL; + } + timr->it.real.timer.expires = (unsigned long)expire_64; + tstojiffie(&new_setting->it_interval, clock->res, &expire_64); + timr->it.real.incr = (unsigned long)expire_64; + + /* + * We do not even queue SIGEV_NONE timers! But we do put them + * in the abs list so we can do that right. + */ + if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE)) + add_timer(&timr->it.real.timer); + + if (flags & TIMER_ABSTIME && clock->abs_struct) { + spin_lock(&clock->abs_struct->lock); + list_add_tail(&(timr->it.real.abs_timer_entry), + &(clock->abs_struct->list)); + spin_unlock(&clock->abs_struct->lock); + } + 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 ((!good_timespec(&new_spec.it_interval)) || + (!good_timespec(&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.incr = 0; +#ifdef CONFIG_SMP + if (timer_active(timer) && !del_timer(&timer->it.real.timer)) + /* + * It can only be active if on an other cpu. Since + * we have cleared the interval stuff above, it should + * clear once we release the spin lock. Of course once + * we do that anything could happen, including the + * complete melt down of the timer. So return with + * a "retry" exit status. + */ + return TIMER_RETRY; +#else + del_timer(&timer->it.real.timer); +#endif + remove_from_abslist(timer); + + 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; + +#ifdef CONFIG_SMP + int error; +retry_delete: +#endif + timer = lock_timer(timer_id, &flags); + if (!timer) + return -EINVAL; + +#ifdef CONFIG_SMP + error = timer_delete_hook(timer); + + if (error == TIMER_RETRY) { + unlock_timer(timer, flags); + goto retry_delete; + } +#else + timer_delete_hook(timer); +#endif + 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 inline void itimer_delete(struct k_itimer *timer) +{ + unsigned long flags; + +#ifdef CONFIG_SMP + int error; +retry_delete: +#endif + spin_lock_irqsave(&timer->it_lock, flags); + +#ifdef CONFIG_SMP + error = timer_delete_hook(timer); + + if (error == TIMER_RETRY) { + unlock_timer(timer, flags); + goto retry_delete; + } +#else + timer_delete_hook(timer); +#endif + 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 __exit_signal, 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); + } +} + +/* + * And now for the "clock" calls + * + * These functions are called both from timer functions (with the timer + * spin_lock_irq() held and from clock calls with no locking. They must + * use the save flags versions of locks. + */ + +/* + * We do ticks here to avoid the irq lock ( they take sooo long). + * The seqlock is great here. Since we a reader, we don't really care + * if we are interrupted since we don't take lock that will stall us or + * any other cpu. Voila, no irq lock is needed. + * + */ + +static u64 do_posix_clock_monotonic_gettime_parts( + struct timespec *tp, struct timespec *mo) +{ + u64 jiff; + unsigned int seq; + + do { + seq = read_seqbegin(&xtime_lock); + getnstimeofday(tp); + *mo = wall_to_monotonic; + jiff = jiffies_64; + + } while(read_seqretry(&xtime_lock, seq)); + + return jiff; +} + +static int do_posix_clock_monotonic_get(clockid_t clock, struct timespec *tp) +{ + struct timespec wall_to_mono; + + do_posix_clock_monotonic_gettime_parts(tp, &wall_to_mono); + + tp->tv_sec += wall_to_mono.tv_sec; + tp->tv_nsec += wall_to_mono.tv_nsec; + + if ((tp->tv_nsec - NSEC_PER_SEC) > 0) { + tp->tv_nsec -= NSEC_PER_SEC; + tp->tv_sec++; + } + return 0; +} + +int do_posix_clock_monotonic_gettime(struct timespec *tp) +{ + return do_posix_clock_monotonic_get(CLOCK_MONOTONIC, tp); +} + +int do_posix_clock_nosettime(clockid_t clockid, struct timespec *tp) +{ + return -EINVAL; +} +EXPORT_SYMBOL_GPL(do_posix_clock_nosettime); + +int do_posix_clock_notimer_create(struct k_itimer *timer) +{ + return -EINVAL; +} +EXPORT_SYMBOL_GPL(do_posix_clock_notimer_create); + +int do_posix_clock_nonanosleep(clockid_t clock, int flags, struct timespec *t) +{ +#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(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(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(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; +} + +static void nanosleep_wake_up(unsigned long __data) +{ + struct task_struct *p = (struct task_struct *) __data; + + wake_up_process(p); +} + +/* + * The standard says that an absolute nanosleep call MUST wake up at + * the requested time in spite of clock settings. Here is what we do: + * For each nanosleep call that needs it (only absolute and not on + * CLOCK_MONOTONIC* (as it can not be set)) we thread a little structure + * into the "nanosleep_abs_list". All we need is the task_struct pointer. + * When ever the clock is set we just wake up all those tasks. The rest + * is done by the while loop in clock_nanosleep(). + * + * On locking, clock_was_set() is called from update_wall_clock which + * holds (or has held for it) a write_lock_irq( xtime_lock) and is + * called from the timer bh code. Thus we need the irq save locks. + * + * Also, on the call from update_wall_clock, that is done as part of a + * softirq thing. We don't want to delay the system that much (possibly + * long list of timers to fix), so we defer that work to keventd. + */ + +static DECLARE_WAIT_QUEUE_HEAD(nanosleep_abs_wqueue); +static DECLARE_WORK(clock_was_set_work, (void(*)(void*))clock_was_set, NULL); + +static DECLARE_MUTEX(clock_was_set_lock); + +void clock_was_set(void) +{ + struct k_itimer *timr; + struct timespec new_wall_to; + LIST_HEAD(cws_list); + unsigned long seq; + + + if (unlikely(in_interrupt())) { + schedule_work(&clock_was_set_work); + return; + } + wake_up_all(&nanosleep_abs_wqueue); + + /* + * Check if there exist TIMER_ABSTIME timers to correct. + * + * Notes on locking: This code is run in task context with irq + * on. We CAN be interrupted! All other usage of the abs list + * lock is under the timer lock which holds the irq lock as + * well. We REALLY don't want to scan the whole list with the + * interrupt system off, AND we would like a sequence lock on + * this code as well. Since we assume that the clock will not + * be set often, it seems ok to take and release the irq lock + * for each timer. In fact add_timer will do this, so this is + * not an issue. So we know when we are done, we will move the + * whole list to a new location. Then as we process each entry, + * we will move it to the actual list again. This way, when our + * copy is empty, we are done. We are not all that concerned + * about preemption so we will use a semaphore lock to protect + * aginst reentry. This way we will not stall another + * processor. It is possible that this may delay some timers + * that should have expired, given the new clock, but even this + * will be minimal as we will always update to the current time, + * even if it was set by a task that is waiting for entry to + * this code. Timers that expire too early will be caught by + * the expire code and restarted. + + * Absolute timers that repeat are left in the abs list while + * waiting for the task to pick up the signal. This means we + * may find timers that are not in the "add_timer" list, but are + * in the abs list. We do the same thing for these, save + * putting them back in the "add_timer" list. (Note, these are + * left in the abs list mainly to indicate that they are + * ABSOLUTE timers, a fact that is used by the re-arm code, and + * for which we have no other flag.) + + */ + + down(&clock_was_set_lock); + spin_lock_irq(&abs_list.lock); + list_splice_init(&abs_list.list, &cws_list); + spin_unlock_irq(&abs_list.lock); + do { + do { + seq = read_seqbegin(&xtime_lock); + new_wall_to = wall_to_monotonic; + } while (read_seqretry(&xtime_lock, seq)); + + spin_lock_irq(&abs_list.lock); + if (list_empty(&cws_list)) { + spin_unlock_irq(&abs_list.lock); + break; + } + timr = list_entry(cws_list.next, struct k_itimer, + it.real.abs_timer_entry); + + list_del_init(&timr->it.real.abs_timer_entry); + if (add_clockset_delta(timr, &new_wall_to) && + del_timer(&timr->it.real.timer)) /* timer run yet? */ + add_timer(&timr->it.real.timer); + list_add(&timr->it.real.abs_timer_entry, &abs_list.list); + spin_unlock_irq(&abs_list.lock); + } while (1); + + up(&clock_was_set_lock); +} + +long clock_nanosleep_restart(struct restart_block *restart_block); + +asmlinkage long +sys_clock_nanosleep(clockid_t which_clock, int flags, + const struct timespec __user *rqtp, + struct timespec __user *rmtp) +{ + struct timespec t; + struct restart_block *restart_block = + &(current_thread_info()->restart_block); + int ret; + + if (invalid_clockid(which_clock)) + return -EINVAL; + + if (copy_from_user(&t, rqtp, sizeof (struct timespec))) + return -EFAULT; + + if ((unsigned) t.tv_nsec >= NSEC_PER_SEC || t.tv_sec < 0) + return -EINVAL; + + /* + * Do this here as nsleep function does not have the real address. + */ + restart_block->arg1 = (unsigned long)rmtp; + + ret = CLOCK_DISPATCH(which_clock, nsleep, (which_clock, flags, &t)); + + if ((ret == -ERESTART_RESTARTBLOCK) && rmtp && + copy_to_user(rmtp, &t, sizeof (t))) + return -EFAULT; + return ret; +} + + +static int common_nsleep(clockid_t which_clock, + int flags, struct timespec *tsave) +{ + struct timespec t, dum; + struct timer_list new_timer; + DECLARE_WAITQUEUE(abs_wqueue, current); + u64 rq_time = (u64)0; + s64 left; + int abs; + struct restart_block *restart_block = + ¤t_thread_info()->restart_block; + + abs_wqueue.flags = 0; + init_timer(&new_timer); + new_timer.expires = 0; + new_timer.data = (unsigned long) current; + new_timer.function = nanosleep_wake_up; + abs = flags & TIMER_ABSTIME; + + if (restart_block->fn == clock_nanosleep_restart) { + /* + * Interrupted by a non-delivered signal, pick up remaining + * time and continue. Remaining time is in arg2 & 3. + */ + restart_block->fn = do_no_restart_syscall; + + rq_time = restart_block->arg3; + rq_time = (rq_time << 32) + restart_block->arg2; + if (!rq_time) + return -EINTR; + left = rq_time - get_jiffies_64(); + if (left <= (s64)0) + return 0; /* Already passed */ + } + + if (abs && (posix_clocks[which_clock].clock_get != + posix_clocks[CLOCK_MONOTONIC].clock_get)) + add_wait_queue(&nanosleep_abs_wqueue, &abs_wqueue); + + do { + t = *tsave; + if (abs || !rq_time) { + adjust_abs_time(&posix_clocks[which_clock], &t, abs, + &rq_time, &dum); + } + + left = rq_time - get_jiffies_64(); + if (left >= (s64)MAX_JIFFY_OFFSET) + left = (s64)MAX_JIFFY_OFFSET; + if (left < (s64)0) + break; + + new_timer.expires = jiffies + left; + __set_current_state(TASK_INTERRUPTIBLE); + add_timer(&new_timer); + + schedule(); + + del_timer_sync(&new_timer); + left = rq_time - get_jiffies_64(); + } while (left > (s64)0 && !test_thread_flag(TIF_SIGPENDING)); + + if (abs_wqueue.task_list.next) + finish_wait(&nanosleep_abs_wqueue, &abs_wqueue); + + if (left > (s64)0) { + + /* + * Always restart abs calls from scratch to pick up any + * clock shifting that happened while we are away. + */ + if (abs) + return -ERESTARTNOHAND; + + left *= TICK_NSEC; + tsave->tv_sec = div_long_long_rem(left, + NSEC_PER_SEC, + &tsave->tv_nsec); + /* + * Restart works by saving the time remaing in + * arg2 & 3 (it is 64-bits of jiffies). The other + * info we need is the clock_id (saved in arg0). + * The sys_call interface needs the users + * timespec return address which _it_ saves in arg1. + * Since we have cast the nanosleep call to a clock_nanosleep + * both can be restarted with the same code. + */ + restart_block->fn = clock_nanosleep_restart; + restart_block->arg0 = which_clock; + /* + * Caller sets arg1 + */ + restart_block->arg2 = rq_time & 0xffffffffLL; + restart_block->arg3 = rq_time >> 32; + + return -ERESTART_RESTARTBLOCK; + } + + return 0; +} +/* + * This will restart clock_nanosleep. + */ +long +clock_nanosleep_restart(struct restart_block *restart_block) +{ + struct timespec t; + int ret = common_nsleep(restart_block->arg0, 0, &t); + + if ((ret == -ERESTART_RESTARTBLOCK) && restart_block->arg1 && + copy_to_user((struct timespec __user *)(restart_block->arg1), &t, + sizeof (t))) + return -EFAULT; + return ret; +} |