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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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9886f44412
David pointed out, that WARN_ONCE() to report usage of an deprecated misfeature make folks unhappy. Use printk_once() instead. Andrew told me to stop grumbling and to remove the silly typecast while touching the file. Reported-by: David Rientjes <rientjes@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
302 lines
7.3 KiB
C
302 lines
7.3 KiB
C
/*
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* linux/kernel/itimer.c
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*
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* Copyright (C) 1992 Darren Senn
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*/
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/* These are all the functions necessary to implement itimers */
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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#include <linux/syscalls.h>
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#include <linux/time.h>
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#include <linux/posix-timers.h>
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#include <linux/hrtimer.h>
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#include <trace/events/timer.h>
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#include <asm/uaccess.h>
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/**
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* itimer_get_remtime - get remaining time for the timer
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*
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* @timer: the timer to read
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*
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* Returns the delta between the expiry time and now, which can be
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* less than zero or 1usec for an pending expired timer
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*/
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static struct timeval itimer_get_remtime(struct hrtimer *timer)
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{
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ktime_t rem = hrtimer_get_remaining(timer);
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/*
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* Racy but safe: if the itimer expires after the above
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* hrtimer_get_remtime() call but before this condition
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* then we return 0 - which is correct.
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*/
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if (hrtimer_active(timer)) {
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if (rem.tv64 <= 0)
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rem.tv64 = NSEC_PER_USEC;
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} else
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rem.tv64 = 0;
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return ktime_to_timeval(rem);
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}
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static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
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struct itimerval *const value)
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{
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cputime_t cval, cinterval;
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struct cpu_itimer *it = &tsk->signal->it[clock_id];
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spin_lock_irq(&tsk->sighand->siglock);
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cval = it->expires;
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cinterval = it->incr;
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if (cval) {
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struct task_cputime cputime;
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cputime_t t;
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thread_group_cputimer(tsk, &cputime);
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if (clock_id == CPUCLOCK_PROF)
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t = cputime.utime + cputime.stime;
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else
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/* CPUCLOCK_VIRT */
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t = cputime.utime;
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if (cval < t)
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/* about to fire */
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cval = cputime_one_jiffy;
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else
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cval = cval - t;
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}
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spin_unlock_irq(&tsk->sighand->siglock);
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cputime_to_timeval(cval, &value->it_value);
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cputime_to_timeval(cinterval, &value->it_interval);
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}
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int do_getitimer(int which, struct itimerval *value)
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{
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struct task_struct *tsk = current;
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switch (which) {
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case ITIMER_REAL:
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spin_lock_irq(&tsk->sighand->siglock);
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value->it_value = itimer_get_remtime(&tsk->signal->real_timer);
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value->it_interval =
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ktime_to_timeval(tsk->signal->it_real_incr);
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spin_unlock_irq(&tsk->sighand->siglock);
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break;
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case ITIMER_VIRTUAL:
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get_cpu_itimer(tsk, CPUCLOCK_VIRT, value);
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break;
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case ITIMER_PROF:
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get_cpu_itimer(tsk, CPUCLOCK_PROF, value);
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break;
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default:
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return(-EINVAL);
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}
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return 0;
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}
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SYSCALL_DEFINE2(getitimer, int, which, struct itimerval __user *, value)
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{
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int error = -EFAULT;
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struct itimerval get_buffer;
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if (value) {
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error = do_getitimer(which, &get_buffer);
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if (!error &&
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copy_to_user(value, &get_buffer, sizeof(get_buffer)))
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error = -EFAULT;
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}
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return error;
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}
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/*
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* The timer is automagically restarted, when interval != 0
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*/
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enum hrtimer_restart it_real_fn(struct hrtimer *timer)
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{
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struct signal_struct *sig =
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container_of(timer, struct signal_struct, real_timer);
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trace_itimer_expire(ITIMER_REAL, sig->leader_pid, 0);
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kill_pid_info(SIGALRM, SEND_SIG_PRIV, sig->leader_pid);
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return HRTIMER_NORESTART;
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}
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static inline u32 cputime_sub_ns(cputime_t ct, s64 real_ns)
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{
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struct timespec ts;
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s64 cpu_ns;
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cputime_to_timespec(ct, &ts);
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cpu_ns = timespec_to_ns(&ts);
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return (cpu_ns <= real_ns) ? 0 : cpu_ns - real_ns;
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}
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static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
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const struct itimerval *const value,
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struct itimerval *const ovalue)
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{
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cputime_t cval, nval, cinterval, ninterval;
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s64 ns_ninterval, ns_nval;
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u32 error, incr_error;
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struct cpu_itimer *it = &tsk->signal->it[clock_id];
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nval = timeval_to_cputime(&value->it_value);
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ns_nval = timeval_to_ns(&value->it_value);
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ninterval = timeval_to_cputime(&value->it_interval);
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ns_ninterval = timeval_to_ns(&value->it_interval);
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error = cputime_sub_ns(nval, ns_nval);
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incr_error = cputime_sub_ns(ninterval, ns_ninterval);
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spin_lock_irq(&tsk->sighand->siglock);
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cval = it->expires;
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cinterval = it->incr;
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if (cval || nval) {
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if (nval > 0)
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nval += cputime_one_jiffy;
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set_process_cpu_timer(tsk, clock_id, &nval, &cval);
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}
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it->expires = nval;
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it->incr = ninterval;
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it->error = error;
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it->incr_error = incr_error;
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trace_itimer_state(clock_id == CPUCLOCK_VIRT ?
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ITIMER_VIRTUAL : ITIMER_PROF, value, nval);
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spin_unlock_irq(&tsk->sighand->siglock);
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if (ovalue) {
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cputime_to_timeval(cval, &ovalue->it_value);
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cputime_to_timeval(cinterval, &ovalue->it_interval);
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}
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}
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/*
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* Returns true if the timeval is in canonical form
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*/
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#define timeval_valid(t) \
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(((t)->tv_sec >= 0) && (((unsigned long) (t)->tv_usec) < USEC_PER_SEC))
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int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
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{
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struct task_struct *tsk = current;
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struct hrtimer *timer;
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ktime_t expires;
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/*
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* Validate the timevals in value.
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*/
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if (!timeval_valid(&value->it_value) ||
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!timeval_valid(&value->it_interval))
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return -EINVAL;
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switch (which) {
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case ITIMER_REAL:
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again:
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spin_lock_irq(&tsk->sighand->siglock);
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timer = &tsk->signal->real_timer;
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if (ovalue) {
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ovalue->it_value = itimer_get_remtime(timer);
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ovalue->it_interval
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= ktime_to_timeval(tsk->signal->it_real_incr);
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}
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/* We are sharing ->siglock with it_real_fn() */
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if (hrtimer_try_to_cancel(timer) < 0) {
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spin_unlock_irq(&tsk->sighand->siglock);
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goto again;
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}
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expires = timeval_to_ktime(value->it_value);
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if (expires.tv64 != 0) {
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tsk->signal->it_real_incr =
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timeval_to_ktime(value->it_interval);
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hrtimer_start(timer, expires, HRTIMER_MODE_REL);
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} else
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tsk->signal->it_real_incr.tv64 = 0;
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trace_itimer_state(ITIMER_REAL, value, 0);
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spin_unlock_irq(&tsk->sighand->siglock);
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break;
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case ITIMER_VIRTUAL:
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set_cpu_itimer(tsk, CPUCLOCK_VIRT, value, ovalue);
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break;
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case ITIMER_PROF:
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set_cpu_itimer(tsk, CPUCLOCK_PROF, value, ovalue);
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break;
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default:
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return -EINVAL;
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}
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return 0;
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}
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/**
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* alarm_setitimer - set alarm in seconds
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*
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* @seconds: number of seconds until alarm
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* 0 disables the alarm
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*
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* Returns the remaining time in seconds of a pending timer or 0 when
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* the timer is not active.
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*
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* On 32 bit machines the seconds value is limited to (INT_MAX/2) to avoid
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* negative timeval settings which would cause immediate expiry.
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*/
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unsigned int alarm_setitimer(unsigned int seconds)
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{
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struct itimerval it_new, it_old;
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#if BITS_PER_LONG < 64
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if (seconds > INT_MAX)
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seconds = INT_MAX;
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#endif
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it_new.it_value.tv_sec = seconds;
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it_new.it_value.tv_usec = 0;
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it_new.it_interval.tv_sec = it_new.it_interval.tv_usec = 0;
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do_setitimer(ITIMER_REAL, &it_new, &it_old);
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/*
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* We can't return 0 if we have an alarm pending ... And we'd
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* better return too much than too little anyway
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*/
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if ((!it_old.it_value.tv_sec && it_old.it_value.tv_usec) ||
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it_old.it_value.tv_usec >= 500000)
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it_old.it_value.tv_sec++;
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return it_old.it_value.tv_sec;
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}
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SYSCALL_DEFINE3(setitimer, int, which, struct itimerval __user *, value,
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struct itimerval __user *, ovalue)
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{
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struct itimerval set_buffer, get_buffer;
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int error;
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if (value) {
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if(copy_from_user(&set_buffer, value, sizeof(set_buffer)))
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return -EFAULT;
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} else {
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memset(&set_buffer, 0, sizeof(set_buffer));
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printk_once(KERN_WARNING "%s calls setitimer() with new_value NULL pointer."
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" Misfeature support will be removed\n",
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current->comm);
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}
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error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : NULL);
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if (error || !ovalue)
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return error;
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if (copy_to_user(ovalue, &get_buffer, sizeof(get_buffer)))
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return -EFAULT;
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return 0;
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}
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