From 5cee964597260237dd2cabb3ec22bba0da24b25d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 22 Jun 2014 12:06:40 +0200 Subject: time/timers: Move all time(r) related files into kernel/time Except for Kconfig.HZ. That needs a separate treatment. Signed-off-by: Thomas Gleixner --- kernel/time/itimer.c | 301 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 301 insertions(+) create mode 100644 kernel/time/itimer.c (limited to 'kernel/time/itimer.c') diff --git a/kernel/time/itimer.c b/kernel/time/itimer.c new file mode 100644 index 000000000000..8d262b467573 --- /dev/null +++ b/kernel/time/itimer.c @@ -0,0 +1,301 @@ +/* + * linux/kernel/itimer.c + * + * Copyright (C) 1992 Darren Senn + */ + +/* These are all the functions necessary to implement itimers */ + +#include +#include +#include +#include +#include +#include +#include + +#include + +/** + * itimer_get_remtime - get remaining time for the timer + * + * @timer: the timer to read + * + * Returns the delta between the expiry time and now, which can be + * less than zero or 1usec for an pending expired timer + */ +static struct timeval itimer_get_remtime(struct hrtimer *timer) +{ + ktime_t rem = hrtimer_get_remaining(timer); + + /* + * Racy but safe: if the itimer expires after the above + * hrtimer_get_remtime() call but before this condition + * then we return 0 - which is correct. + */ + if (hrtimer_active(timer)) { + if (rem.tv64 <= 0) + rem.tv64 = NSEC_PER_USEC; + } else + rem.tv64 = 0; + + return ktime_to_timeval(rem); +} + +static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, + struct itimerval *const value) +{ + cputime_t cval, cinterval; + struct cpu_itimer *it = &tsk->signal->it[clock_id]; + + spin_lock_irq(&tsk->sighand->siglock); + + cval = it->expires; + cinterval = it->incr; + if (cval) { + struct task_cputime cputime; + cputime_t t; + + thread_group_cputimer(tsk, &cputime); + if (clock_id == CPUCLOCK_PROF) + t = cputime.utime + cputime.stime; + else + /* CPUCLOCK_VIRT */ + t = cputime.utime; + + if (cval < t) + /* about to fire */ + cval = cputime_one_jiffy; + else + cval = cval - t; + } + + spin_unlock_irq(&tsk->sighand->siglock); + + cputime_to_timeval(cval, &value->it_value); + cputime_to_timeval(cinterval, &value->it_interval); +} + +int do_getitimer(int which, struct itimerval *value) +{ + struct task_struct *tsk = current; + + switch (which) { + case ITIMER_REAL: + spin_lock_irq(&tsk->sighand->siglock); + value->it_value = itimer_get_remtime(&tsk->signal->real_timer); + value->it_interval = + ktime_to_timeval(tsk->signal->it_real_incr); + spin_unlock_irq(&tsk->sighand->siglock); + break; + case ITIMER_VIRTUAL: + get_cpu_itimer(tsk, CPUCLOCK_VIRT, value); + break; + case ITIMER_PROF: + get_cpu_itimer(tsk, CPUCLOCK_PROF, value); + break; + default: + return(-EINVAL); + } + return 0; +} + +SYSCALL_DEFINE2(getitimer, int, which, struct itimerval __user *, value) +{ + int error = -EFAULT; + struct itimerval get_buffer; + + if (value) { + error = do_getitimer(which, &get_buffer); + if (!error && + copy_to_user(value, &get_buffer, sizeof(get_buffer))) + error = -EFAULT; + } + return error; +} + + +/* + * The timer is automagically restarted, when interval != 0 + */ +enum hrtimer_restart it_real_fn(struct hrtimer *timer) +{ + struct signal_struct *sig = + container_of(timer, struct signal_struct, real_timer); + + trace_itimer_expire(ITIMER_REAL, sig->leader_pid, 0); + kill_pid_info(SIGALRM, SEND_SIG_PRIV, sig->leader_pid); + + return HRTIMER_NORESTART; +} + +static inline u32 cputime_sub_ns(cputime_t ct, s64 real_ns) +{ + struct timespec ts; + s64 cpu_ns; + + cputime_to_timespec(ct, &ts); + cpu_ns = timespec_to_ns(&ts); + + return (cpu_ns <= real_ns) ? 0 : cpu_ns - real_ns; +} + +static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, + const struct itimerval *const value, + struct itimerval *const ovalue) +{ + cputime_t cval, nval, cinterval, ninterval; + s64 ns_ninterval, ns_nval; + u32 error, incr_error; + struct cpu_itimer *it = &tsk->signal->it[clock_id]; + + nval = timeval_to_cputime(&value->it_value); + ns_nval = timeval_to_ns(&value->it_value); + ninterval = timeval_to_cputime(&value->it_interval); + ns_ninterval = timeval_to_ns(&value->it_interval); + + error = cputime_sub_ns(nval, ns_nval); + incr_error = cputime_sub_ns(ninterval, ns_ninterval); + + spin_lock_irq(&tsk->sighand->siglock); + + cval = it->expires; + cinterval = it->incr; + if (cval || nval) { + if (nval > 0) + nval += cputime_one_jiffy; + set_process_cpu_timer(tsk, clock_id, &nval, &cval); + } + it->expires = nval; + it->incr = ninterval; + it->error = error; + it->incr_error = incr_error; + trace_itimer_state(clock_id == CPUCLOCK_VIRT ? + ITIMER_VIRTUAL : ITIMER_PROF, value, nval); + + spin_unlock_irq(&tsk->sighand->siglock); + + if (ovalue) { + cputime_to_timeval(cval, &ovalue->it_value); + cputime_to_timeval(cinterval, &ovalue->it_interval); + } +} + +/* + * Returns true if the timeval is in canonical form + */ +#define timeval_valid(t) \ + (((t)->tv_sec >= 0) && (((unsigned long) (t)->tv_usec) < USEC_PER_SEC)) + +int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue) +{ + struct task_struct *tsk = current; + struct hrtimer *timer; + ktime_t expires; + + /* + * Validate the timevals in value. + */ + if (!timeval_valid(&value->it_value) || + !timeval_valid(&value->it_interval)) + return -EINVAL; + + switch (which) { + case ITIMER_REAL: +again: + spin_lock_irq(&tsk->sighand->siglock); + timer = &tsk->signal->real_timer; + if (ovalue) { + ovalue->it_value = itimer_get_remtime(timer); + ovalue->it_interval + = ktime_to_timeval(tsk->signal->it_real_incr); + } + /* We are sharing ->siglock with it_real_fn() */ + if (hrtimer_try_to_cancel(timer) < 0) { + spin_unlock_irq(&tsk->sighand->siglock); + goto again; + } + expires = timeval_to_ktime(value->it_value); + if (expires.tv64 != 0) { + tsk->signal->it_real_incr = + timeval_to_ktime(value->it_interval); + hrtimer_start(timer, expires, HRTIMER_MODE_REL); + } else + tsk->signal->it_real_incr.tv64 = 0; + + trace_itimer_state(ITIMER_REAL, value, 0); + spin_unlock_irq(&tsk->sighand->siglock); + break; + case ITIMER_VIRTUAL: + set_cpu_itimer(tsk, CPUCLOCK_VIRT, value, ovalue); + break; + case ITIMER_PROF: + set_cpu_itimer(tsk, CPUCLOCK_PROF, value, ovalue); + break; + default: + return -EINVAL; + } + return 0; +} + +/** + * alarm_setitimer - set alarm in seconds + * + * @seconds: number of seconds until alarm + * 0 disables the alarm + * + * Returns the remaining time in seconds of a pending timer or 0 when + * the timer is not active. + * + * On 32 bit machines the seconds value is limited to (INT_MAX/2) to avoid + * negative timeval settings which would cause immediate expiry. + */ +unsigned int alarm_setitimer(unsigned int seconds) +{ + struct itimerval it_new, it_old; + +#if BITS_PER_LONG < 64 + if (seconds > INT_MAX) + seconds = INT_MAX; +#endif + it_new.it_value.tv_sec = seconds; + it_new.it_value.tv_usec = 0; + it_new.it_interval.tv_sec = it_new.it_interval.tv_usec = 0; + + do_setitimer(ITIMER_REAL, &it_new, &it_old); + + /* + * We can't return 0 if we have an alarm pending ... And we'd + * better return too much than too little anyway + */ + if ((!it_old.it_value.tv_sec && it_old.it_value.tv_usec) || + it_old.it_value.tv_usec >= 500000) + it_old.it_value.tv_sec++; + + return it_old.it_value.tv_sec; +} + +SYSCALL_DEFINE3(setitimer, int, which, struct itimerval __user *, value, + struct itimerval __user *, ovalue) +{ + struct itimerval set_buffer, get_buffer; + int error; + + if (value) { + if(copy_from_user(&set_buffer, value, sizeof(set_buffer))) + return -EFAULT; + } else { + memset(&set_buffer, 0, sizeof(set_buffer)); + printk_once(KERN_WARNING "%s calls setitimer() with new_value NULL pointer." + " Misfeature support will be removed\n", + current->comm); + } + + error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : NULL); + if (error || !ovalue) + return error; + + if (copy_to_user(ovalue, &get_buffer, sizeof(get_buffer))) + return -EFAULT; + return 0; +} -- cgit v1.2.3