// SPDX-License-Identifier: GPL-2.0
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/*
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* Implement CPU time clocks for the POSIX clock interface.
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*/
|
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#include <linux/sched/signal.h>
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#include <linux/sched/cputime.h>
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#include <linux/posix-timers.h>
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#include <linux/errno.h>
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#include <linux/math64.h>
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#include <linux/uaccess.h>
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#include <linux/kernel_stat.h>
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#include <trace/events/timer.h>
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#include <linux/tick.h>
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#include <linux/workqueue.h>
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#include <linux/compat.h>
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#include <linux/sched/deadline.h>
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#include "posix-timers.h"
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static void posix_cpu_timer_rearm(struct k_itimer *timer);
|
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void posix_cputimers_group_init(struct posix_cputimers *pct, u64 cpu_limit)
|
{
|
posix_cputimers_init(pct);
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if (cpu_limit != RLIM_INFINITY) {
|
pct->bases[CPUCLOCK_PROF].nextevt = cpu_limit * NSEC_PER_SEC;
|
pct->timers_active = true;
|
}
|
}
|
|
/*
|
* Called after updating RLIMIT_CPU to run cpu timer and update
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* tsk->signal->posix_cputimers.bases[clock].nextevt expiration cache if
|
* necessary. Needs siglock protection since other code may update the
|
* expiration cache as well.
|
*/
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void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new)
|
{
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u64 nsecs = rlim_new * NSEC_PER_SEC;
|
|
spin_lock_irq(&task->sighand->siglock);
|
set_process_cpu_timer(task, CPUCLOCK_PROF, &nsecs, NULL);
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spin_unlock_irq(&task->sighand->siglock);
|
}
|
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/*
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* Functions for validating access to tasks.
|
*/
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static struct pid *pid_for_clock(const clockid_t clock, bool gettime)
|
{
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const bool thread = !!CPUCLOCK_PERTHREAD(clock);
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const pid_t upid = CPUCLOCK_PID(clock);
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struct pid *pid;
|
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if (CPUCLOCK_WHICH(clock) >= CPUCLOCK_MAX)
|
return NULL;
|
|
/*
|
* If the encoded PID is 0, then the timer is targeted at current
|
* or the process to which current belongs.
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*/
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if (upid == 0)
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return thread ? task_pid(current) : task_tgid(current);
|
|
pid = find_vpid(upid);
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if (!pid)
|
return NULL;
|
|
if (thread) {
|
struct task_struct *tsk = pid_task(pid, PIDTYPE_PID);
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return (tsk && same_thread_group(tsk, current)) ? pid : NULL;
|
}
|
|
/*
|
* For clock_gettime(PROCESS) allow finding the process by
|
* with the pid of the current task. The code needs the tgid
|
* of the process so that pid_task(pid, PIDTYPE_TGID) can be
|
* used to find the process.
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*/
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if (gettime && (pid == task_pid(current)))
|
return task_tgid(current);
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/*
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* For processes require that pid identifies a process.
|
*/
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return pid_has_task(pid, PIDTYPE_TGID) ? pid : NULL;
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}
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static inline int validate_clock_permissions(const clockid_t clock)
|
{
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int ret;
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|
rcu_read_lock();
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ret = pid_for_clock(clock, false) ? 0 : -EINVAL;
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rcu_read_unlock();
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return ret;
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}
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static inline enum pid_type clock_pid_type(const clockid_t clock)
|
{
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return CPUCLOCK_PERTHREAD(clock) ? PIDTYPE_PID : PIDTYPE_TGID;
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}
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static inline struct task_struct *cpu_timer_task_rcu(struct k_itimer *timer)
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{
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return pid_task(timer->it.cpu.pid, clock_pid_type(timer->it_clock));
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}
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/*
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* Update expiry time from increment, and increase overrun count,
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* given the current clock sample.
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*/
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static u64 bump_cpu_timer(struct k_itimer *timer, u64 now)
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{
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u64 delta, incr, expires = timer->it.cpu.node.expires;
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int i;
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if (!timer->it_interval)
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return expires;
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if (now < expires)
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return expires;
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incr = timer->it_interval;
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delta = now + incr - expires;
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/* Don't use (incr*2 < delta), incr*2 might overflow. */
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for (i = 0; incr < delta - incr; i++)
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incr = incr << 1;
|
|
for (; i >= 0; incr >>= 1, i--) {
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if (delta < incr)
|
continue;
|
|
timer->it.cpu.node.expires += incr;
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timer->it_overrun += 1LL << i;
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delta -= incr;
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}
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return timer->it.cpu.node.expires;
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}
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/* Check whether all cache entries contain U64_MAX, i.e. eternal expiry time */
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static inline bool expiry_cache_is_inactive(const struct posix_cputimers *pct)
|
{
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return !(~pct->bases[CPUCLOCK_PROF].nextevt |
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~pct->bases[CPUCLOCK_VIRT].nextevt |
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~pct->bases[CPUCLOCK_SCHED].nextevt);
|
}
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static int
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posix_cpu_clock_getres(const clockid_t which_clock, struct timespec64 *tp)
|
{
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int error = validate_clock_permissions(which_clock);
|
|
if (!error) {
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tp->tv_sec = 0;
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tp->tv_nsec = ((NSEC_PER_SEC + HZ - 1) / HZ);
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if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
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/*
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* If sched_clock is using a cycle counter, we
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* don't have any idea of its true resolution
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* exported, but it is much more than 1s/HZ.
|
*/
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tp->tv_nsec = 1;
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}
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}
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return error;
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}
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static int
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posix_cpu_clock_set(const clockid_t clock, const struct timespec64 *tp)
|
{
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int error = validate_clock_permissions(clock);
|
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/*
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* You can never reset a CPU clock, but we check for other errors
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* in the call before failing with EPERM.
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*/
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return error ? : -EPERM;
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}
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/*
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* Sample a per-thread clock for the given task. clkid is validated.
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*/
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static u64 cpu_clock_sample(const clockid_t clkid, struct task_struct *p)
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{
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u64 utime, stime;
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if (clkid == CPUCLOCK_SCHED)
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return task_sched_runtime(p);
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task_cputime(p, &utime, &stime);
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switch (clkid) {
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case CPUCLOCK_PROF:
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return utime + stime;
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case CPUCLOCK_VIRT:
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return utime;
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default:
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WARN_ON_ONCE(1);
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}
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return 0;
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}
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static inline void store_samples(u64 *samples, u64 stime, u64 utime, u64 rtime)
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{
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samples[CPUCLOCK_PROF] = stime + utime;
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samples[CPUCLOCK_VIRT] = utime;
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samples[CPUCLOCK_SCHED] = rtime;
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}
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static void task_sample_cputime(struct task_struct *p, u64 *samples)
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{
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u64 stime, utime;
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task_cputime(p, &utime, &stime);
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store_samples(samples, stime, utime, p->se.sum_exec_runtime);
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}
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static void proc_sample_cputime_atomic(struct task_cputime_atomic *at,
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u64 *samples)
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{
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u64 stime, utime, rtime;
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utime = atomic64_read(&at->utime);
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stime = atomic64_read(&at->stime);
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rtime = atomic64_read(&at->sum_exec_runtime);
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store_samples(samples, stime, utime, rtime);
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}
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/*
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* Set cputime to sum_cputime if sum_cputime > cputime. Use cmpxchg
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* to avoid race conditions with concurrent updates to cputime.
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*/
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static inline void __update_gt_cputime(atomic64_t *cputime, u64 sum_cputime)
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{
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u64 curr_cputime;
|
retry:
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curr_cputime = atomic64_read(cputime);
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if (sum_cputime > curr_cputime) {
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if (atomic64_cmpxchg(cputime, curr_cputime, sum_cputime) != curr_cputime)
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goto retry;
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}
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}
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static void update_gt_cputime(struct task_cputime_atomic *cputime_atomic,
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struct task_cputime *sum)
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{
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__update_gt_cputime(&cputime_atomic->utime, sum->utime);
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__update_gt_cputime(&cputime_atomic->stime, sum->stime);
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__update_gt_cputime(&cputime_atomic->sum_exec_runtime, sum->sum_exec_runtime);
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}
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/**
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* thread_group_sample_cputime - Sample cputime for a given task
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* @tsk: Task for which cputime needs to be started
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* @samples: Storage for time samples
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*
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* Called from sys_getitimer() to calculate the expiry time of an active
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* timer. That means group cputime accounting is already active. Called
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* with task sighand lock held.
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*
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* Updates @times with an uptodate sample of the thread group cputimes.
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*/
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void thread_group_sample_cputime(struct task_struct *tsk, u64 *samples)
|
{
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struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
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struct posix_cputimers *pct = &tsk->signal->posix_cputimers;
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WARN_ON_ONCE(!pct->timers_active);
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proc_sample_cputime_atomic(&cputimer->cputime_atomic, samples);
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}
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/**
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* thread_group_start_cputime - Start cputime and return a sample
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* @tsk: Task for which cputime needs to be started
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* @samples: Storage for time samples
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*
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* The thread group cputime accouting is avoided when there are no posix
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* CPU timers armed. Before starting a timer it's required to check whether
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* the time accounting is active. If not, a full update of the atomic
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* accounting store needs to be done and the accounting enabled.
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*
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* Updates @times with an uptodate sample of the thread group cputimes.
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*/
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static void thread_group_start_cputime(struct task_struct *tsk, u64 *samples)
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{
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struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
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struct posix_cputimers *pct = &tsk->signal->posix_cputimers;
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/* Check if cputimer isn't running. This is accessed without locking. */
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if (!READ_ONCE(pct->timers_active)) {
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struct task_cputime sum;
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/*
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* The POSIX timer interface allows for absolute time expiry
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* values through the TIMER_ABSTIME flag, therefore we have
|
* to synchronize the timer to the clock every time we start it.
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*/
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thread_group_cputime(tsk, &sum);
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update_gt_cputime(&cputimer->cputime_atomic, &sum);
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/*
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* We're setting timers_active without a lock. Ensure this
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* only gets written to in one operation. We set it after
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* update_gt_cputime() as a small optimization, but
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* barriers are not required because update_gt_cputime()
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* can handle concurrent updates.
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*/
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WRITE_ONCE(pct->timers_active, true);
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}
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proc_sample_cputime_atomic(&cputimer->cputime_atomic, samples);
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}
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static void __thread_group_cputime(struct task_struct *tsk, u64 *samples)
|
{
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struct task_cputime ct;
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|
thread_group_cputime(tsk, &ct);
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store_samples(samples, ct.stime, ct.utime, ct.sum_exec_runtime);
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}
|
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/*
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* Sample a process (thread group) clock for the given task clkid. If the
|
* group's cputime accounting is already enabled, read the atomic
|
* store. Otherwise a full update is required. clkid is already validated.
|
*/
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static u64 cpu_clock_sample_group(const clockid_t clkid, struct task_struct *p,
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bool start)
|
{
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struct thread_group_cputimer *cputimer = &p->signal->cputimer;
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struct posix_cputimers *pct = &p->signal->posix_cputimers;
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u64 samples[CPUCLOCK_MAX];
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if (!READ_ONCE(pct->timers_active)) {
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if (start)
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thread_group_start_cputime(p, samples);
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else
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__thread_group_cputime(p, samples);
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} else {
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proc_sample_cputime_atomic(&cputimer->cputime_atomic, samples);
|
}
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|
return samples[clkid];
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}
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static int posix_cpu_clock_get(const clockid_t clock, struct timespec64 *tp)
|
{
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const clockid_t clkid = CPUCLOCK_WHICH(clock);
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struct task_struct *tsk;
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u64 t;
|
|
rcu_read_lock();
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tsk = pid_task(pid_for_clock(clock, true), clock_pid_type(clock));
|
if (!tsk) {
|
rcu_read_unlock();
|
return -EINVAL;
|
}
|
|
if (CPUCLOCK_PERTHREAD(clock))
|
t = cpu_clock_sample(clkid, tsk);
|
else
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t = cpu_clock_sample_group(clkid, tsk, false);
|
rcu_read_unlock();
|
|
*tp = ns_to_timespec64(t);
|
return 0;
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}
|
|
/*
|
* Validate the clockid_t for a new CPU-clock timer, and initialize the timer.
|
* This is called from sys_timer_create() and do_cpu_nanosleep() with the
|
* new timer already all-zeros initialized.
|
*/
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static int posix_cpu_timer_create(struct k_itimer *new_timer)
|
{
|
static struct lock_class_key posix_cpu_timers_key;
|
struct pid *pid;
|
|
rcu_read_lock();
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pid = pid_for_clock(new_timer->it_clock, false);
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if (!pid) {
|
rcu_read_unlock();
|
return -EINVAL;
|
}
|
|
/*
|
* If posix timer expiry is handled in task work context then
|
* timer::it_lock can be taken without disabling interrupts as all
|
* other locking happens in task context. This requires a seperate
|
* lock class key otherwise regular posix timer expiry would record
|
* the lock class being taken in interrupt context and generate a
|
* false positive warning.
|
*/
|
if (IS_ENABLED(CONFIG_POSIX_CPU_TIMERS_TASK_WORK))
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lockdep_set_class(&new_timer->it_lock, &posix_cpu_timers_key);
|
|
new_timer->kclock = &clock_posix_cpu;
|
timerqueue_init(&new_timer->it.cpu.node);
|
new_timer->it.cpu.pid = get_pid(pid);
|
rcu_read_unlock();
|
return 0;
|
}
|
|
/*
|
* Clean up a CPU-clock timer that is about to be destroyed.
|
* This is called from timer deletion with the timer already locked.
|
* If we return TIMER_RETRY, it's necessary to release the timer's lock
|
* and try again. (This happens when the timer is in the middle of firing.)
|
*/
|
static int posix_cpu_timer_del(struct k_itimer *timer)
|
{
|
struct cpu_timer *ctmr = &timer->it.cpu;
|
struct sighand_struct *sighand;
|
struct task_struct *p;
|
unsigned long flags;
|
int ret = 0;
|
|
rcu_read_lock();
|
p = cpu_timer_task_rcu(timer);
|
if (!p)
|
goto out;
|
|
/*
|
* Protect against sighand release/switch in exit/exec and process/
|
* thread timer list entry concurrent read/writes.
|
*/
|
sighand = lock_task_sighand(p, &flags);
|
if (unlikely(sighand == NULL)) {
|
/*
|
* This raced with the reaping of the task. The exit cleanup
|
* should have removed this timer from the timer queue.
|
*/
|
WARN_ON_ONCE(ctmr->head || timerqueue_node_queued(&ctmr->node));
|
} else {
|
if (timer->it.cpu.firing)
|
ret = TIMER_RETRY;
|
else
|
cpu_timer_dequeue(ctmr);
|
|
unlock_task_sighand(p, &flags);
|
}
|
|
out:
|
rcu_read_unlock();
|
if (!ret)
|
put_pid(ctmr->pid);
|
|
return ret;
|
}
|
|
static void cleanup_timerqueue(struct timerqueue_head *head)
|
{
|
struct timerqueue_node *node;
|
struct cpu_timer *ctmr;
|
|
while ((node = timerqueue_getnext(head))) {
|
timerqueue_del(head, node);
|
ctmr = container_of(node, struct cpu_timer, node);
|
ctmr->head = NULL;
|
}
|
}
|
|
/*
|
* Clean out CPU timers which are still armed when a thread exits. The
|
* timers are only removed from the list. No other updates are done. The
|
* corresponding posix timers are still accessible, but cannot be rearmed.
|
*
|
* This must be called with the siglock held.
|
*/
|
static void cleanup_timers(struct posix_cputimers *pct)
|
{
|
cleanup_timerqueue(&pct->bases[CPUCLOCK_PROF].tqhead);
|
cleanup_timerqueue(&pct->bases[CPUCLOCK_VIRT].tqhead);
|
cleanup_timerqueue(&pct->bases[CPUCLOCK_SCHED].tqhead);
|
}
|
|
/*
|
* These are both called with the siglock held, when the current thread
|
* is being reaped. When the final (leader) thread in the group is reaped,
|
* posix_cpu_timers_exit_group will be called after posix_cpu_timers_exit.
|
*/
|
void posix_cpu_timers_exit(struct task_struct *tsk)
|
{
|
cleanup_timers(&tsk->posix_cputimers);
|
}
|
void posix_cpu_timers_exit_group(struct task_struct *tsk)
|
{
|
cleanup_timers(&tsk->signal->posix_cputimers);
|
}
|
|
/*
|
* Insert the timer on the appropriate list before any timers that
|
* expire later. This must be called with the sighand lock held.
|
*/
|
static void arm_timer(struct k_itimer *timer, struct task_struct *p)
|
{
|
int clkidx = CPUCLOCK_WHICH(timer->it_clock);
|
struct cpu_timer *ctmr = &timer->it.cpu;
|
u64 newexp = cpu_timer_getexpires(ctmr);
|
struct posix_cputimer_base *base;
|
|
if (CPUCLOCK_PERTHREAD(timer->it_clock))
|
base = p->posix_cputimers.bases + clkidx;
|
else
|
base = p->signal->posix_cputimers.bases + clkidx;
|
|
if (!cpu_timer_enqueue(&base->tqhead, ctmr))
|
return;
|
|
/*
|
* We are the new earliest-expiring POSIX 1.b timer, hence
|
* need to update expiration cache. Take into account that
|
* for process timers we share expiration cache with itimers
|
* and RLIMIT_CPU and for thread timers with RLIMIT_RTTIME.
|
*/
|
if (newexp < base->nextevt)
|
base->nextevt = newexp;
|
|
if (CPUCLOCK_PERTHREAD(timer->it_clock))
|
tick_dep_set_task(p, TICK_DEP_BIT_POSIX_TIMER);
|
else
|
tick_dep_set_signal(p->signal, TICK_DEP_BIT_POSIX_TIMER);
|
}
|
|
/*
|
* The timer is locked, fire it and arrange for its reload.
|
*/
|
static void cpu_timer_fire(struct k_itimer *timer)
|
{
|
struct cpu_timer *ctmr = &timer->it.cpu;
|
|
if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
|
/*
|
* User don't want any signal.
|
*/
|
cpu_timer_setexpires(ctmr, 0);
|
} else if (unlikely(timer->sigq == NULL)) {
|
/*
|
* This a special case for clock_nanosleep,
|
* not a normal timer from sys_timer_create.
|
*/
|
wake_up_process(timer->it_process);
|
cpu_timer_setexpires(ctmr, 0);
|
} else if (!timer->it_interval) {
|
/*
|
* One-shot timer. Clear it as soon as it's fired.
|
*/
|
posix_timer_event(timer, 0);
|
cpu_timer_setexpires(ctmr, 0);
|
} else if (posix_timer_event(timer, ++timer->it_requeue_pending)) {
|
/*
|
* The signal did not get queued because the signal
|
* was ignored, so we won't get any callback to
|
* reload the timer. But we need to keep it
|
* ticking in case the signal is deliverable next time.
|
*/
|
posix_cpu_timer_rearm(timer);
|
++timer->it_requeue_pending;
|
}
|
}
|
|
/*
|
* Guts of sys_timer_settime for CPU timers.
|
* This is called with the timer locked and interrupts disabled.
|
* If we return TIMER_RETRY, it's necessary to release the timer's lock
|
* and try again. (This happens when the timer is in the middle of firing.)
|
*/
|
static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
|
struct itimerspec64 *new, struct itimerspec64 *old)
|
{
|
clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock);
|
u64 old_expires, new_expires, old_incr, val;
|
struct cpu_timer *ctmr = &timer->it.cpu;
|
struct sighand_struct *sighand;
|
struct task_struct *p;
|
unsigned long flags;
|
int ret = 0;
|
|
rcu_read_lock();
|
p = cpu_timer_task_rcu(timer);
|
if (!p) {
|
/*
|
* If p has just been reaped, we can no
|
* longer get any information about it at all.
|
*/
|
rcu_read_unlock();
|
return -ESRCH;
|
}
|
|
/*
|
* Use the to_ktime conversion because that clamps the maximum
|
* value to KTIME_MAX and avoid multiplication overflows.
|
*/
|
new_expires = ktime_to_ns(timespec64_to_ktime(new->it_value));
|
|
/*
|
* Protect against sighand release/switch in exit/exec and p->cpu_timers
|
* and p->signal->cpu_timers read/write in arm_timer()
|
*/
|
sighand = lock_task_sighand(p, &flags);
|
/*
|
* If p has just been reaped, we can no
|
* longer get any information about it at all.
|
*/
|
if (unlikely(sighand == NULL)) {
|
rcu_read_unlock();
|
return -ESRCH;
|
}
|
|
/*
|
* Disarm any old timer after extracting its expiry time.
|
*/
|
old_incr = timer->it_interval;
|
old_expires = cpu_timer_getexpires(ctmr);
|
|
if (unlikely(timer->it.cpu.firing)) {
|
timer->it.cpu.firing = -1;
|
ret = TIMER_RETRY;
|
} else {
|
cpu_timer_dequeue(ctmr);
|
}
|
|
/*
|
* We need to sample the current value to convert the new
|
* value from to relative and absolute, and to convert the
|
* old value from absolute to relative. To set a process
|
* timer, we need a sample to balance the thread expiry
|
* times (in arm_timer). With an absolute time, we must
|
* check if it's already passed. In short, we need a sample.
|
*/
|
if (CPUCLOCK_PERTHREAD(timer->it_clock))
|
val = cpu_clock_sample(clkid, p);
|
else
|
val = cpu_clock_sample_group(clkid, p, true);
|
|
if (old) {
|
if (old_expires == 0) {
|
old->it_value.tv_sec = 0;
|
old->it_value.tv_nsec = 0;
|
} else {
|
/*
|
* Update the timer in case it has overrun already.
|
* If it has, we'll report it as having overrun and
|
* with the next reloaded timer already ticking,
|
* though we are swallowing that pending
|
* notification here to install the new setting.
|
*/
|
u64 exp = bump_cpu_timer(timer, val);
|
|
if (val < exp) {
|
old_expires = exp - val;
|
old->it_value = ns_to_timespec64(old_expires);
|
} else {
|
old->it_value.tv_nsec = 1;
|
old->it_value.tv_sec = 0;
|
}
|
}
|
}
|
|
if (unlikely(ret)) {
|
/*
|
* We are colliding with the timer actually firing.
|
* Punt after filling in the timer's old value, and
|
* disable this firing since we are already reporting
|
* it as an overrun (thanks to bump_cpu_timer above).
|
*/
|
unlock_task_sighand(p, &flags);
|
goto out;
|
}
|
|
if (new_expires != 0 && !(timer_flags & TIMER_ABSTIME)) {
|
new_expires += val;
|
}
|
|
/*
|
* Install the new expiry time (or zero).
|
* For a timer with no notification action, we don't actually
|
* arm the timer (we'll just fake it for timer_gettime).
|
*/
|
cpu_timer_setexpires(ctmr, new_expires);
|
if (new_expires != 0 && val < new_expires) {
|
arm_timer(timer, p);
|
}
|
|
unlock_task_sighand(p, &flags);
|
/*
|
* Install the new reload setting, and
|
* set up the signal and overrun bookkeeping.
|
*/
|
timer->it_interval = timespec64_to_ktime(new->it_interval);
|
|
/*
|
* This acts as a modification timestamp for the timer,
|
* so any automatic reload attempt will punt on seeing
|
* that we have reset the timer manually.
|
*/
|
timer->it_requeue_pending = (timer->it_requeue_pending + 2) &
|
~REQUEUE_PENDING;
|
timer->it_overrun_last = 0;
|
timer->it_overrun = -1;
|
|
if (new_expires != 0 && !(val < new_expires)) {
|
/*
|
* The designated time already passed, so we notify
|
* immediately, even if the thread never runs to
|
* accumulate more time on this clock.
|
*/
|
cpu_timer_fire(timer);
|
}
|
|
ret = 0;
|
out:
|
rcu_read_unlock();
|
if (old)
|
old->it_interval = ns_to_timespec64(old_incr);
|
|
return ret;
|
}
|
|
static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec64 *itp)
|
{
|
clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock);
|
struct cpu_timer *ctmr = &timer->it.cpu;
|
u64 now, expires = cpu_timer_getexpires(ctmr);
|
struct task_struct *p;
|
|
rcu_read_lock();
|
p = cpu_timer_task_rcu(timer);
|
if (!p)
|
goto out;
|
|
/*
|
* Easy part: convert the reload time.
|
*/
|
itp->it_interval = ktime_to_timespec64(timer->it_interval);
|
|
if (!expires)
|
goto out;
|
|
/*
|
* Sample the clock to take the difference with the expiry time.
|
*/
|
if (CPUCLOCK_PERTHREAD(timer->it_clock))
|
now = cpu_clock_sample(clkid, p);
|
else
|
now = cpu_clock_sample_group(clkid, p, false);
|
|
if (now < expires) {
|
itp->it_value = ns_to_timespec64(expires - now);
|
} else {
|
/*
|
* The timer should have expired already, but the firing
|
* hasn't taken place yet. Say it's just about to expire.
|
*/
|
itp->it_value.tv_nsec = 1;
|
itp->it_value.tv_sec = 0;
|
}
|
out:
|
rcu_read_unlock();
|
}
|
|
#define MAX_COLLECTED 20
|
|
static u64 collect_timerqueue(struct timerqueue_head *head,
|
struct list_head *firing, u64 now)
|
{
|
struct timerqueue_node *next;
|
int i = 0;
|
|
while ((next = timerqueue_getnext(head))) {
|
struct cpu_timer *ctmr;
|
u64 expires;
|
|
ctmr = container_of(next, struct cpu_timer, node);
|
expires = cpu_timer_getexpires(ctmr);
|
/* Limit the number of timers to expire at once */
|
if (++i == MAX_COLLECTED || now < expires)
|
return expires;
|
|
ctmr->firing = 1;
|
cpu_timer_dequeue(ctmr);
|
list_add_tail(&ctmr->elist, firing);
|
}
|
|
return U64_MAX;
|
}
|
|
static void collect_posix_cputimers(struct posix_cputimers *pct, u64 *samples,
|
struct list_head *firing)
|
{
|
struct posix_cputimer_base *base = pct->bases;
|
int i;
|
|
for (i = 0; i < CPUCLOCK_MAX; i++, base++) {
|
base->nextevt = collect_timerqueue(&base->tqhead, firing,
|
samples[i]);
|
}
|
}
|
|
static inline void check_dl_overrun(struct task_struct *tsk)
|
{
|
if (tsk->dl.dl_overrun) {
|
tsk->dl.dl_overrun = 0;
|
__group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
|
}
|
}
|
|
static bool check_rlimit(u64 time, u64 limit, int signo, bool rt, bool hard)
|
{
|
if (time < limit)
|
return false;
|
|
if (print_fatal_signals) {
|
pr_info("%s Watchdog Timeout (%s): %s[%d]\n",
|
rt ? "RT" : "CPU", hard ? "hard" : "soft",
|
current->comm, task_pid_nr(current));
|
}
|
__group_send_sig_info(signo, SEND_SIG_PRIV, current);
|
return true;
|
}
|
|
/*
|
* Check for any per-thread CPU timers that have fired and move them off
|
* the tsk->cpu_timers[N] list onto the firing list. Here we update the
|
* tsk->it_*_expires values to reflect the remaining thread CPU timers.
|
*/
|
static void check_thread_timers(struct task_struct *tsk,
|
struct list_head *firing)
|
{
|
struct posix_cputimers *pct = &tsk->posix_cputimers;
|
u64 samples[CPUCLOCK_MAX];
|
unsigned long soft;
|
|
if (dl_task(tsk))
|
check_dl_overrun(tsk);
|
|
if (expiry_cache_is_inactive(pct))
|
return;
|
|
task_sample_cputime(tsk, samples);
|
collect_posix_cputimers(pct, samples, firing);
|
|
/*
|
* Check for the special case thread timers.
|
*/
|
soft = task_rlimit(tsk, RLIMIT_RTTIME);
|
if (soft != RLIM_INFINITY) {
|
/* Task RT timeout is accounted in jiffies. RTTIME is usec */
|
unsigned long rttime = tsk->rt.timeout * (USEC_PER_SEC / HZ);
|
unsigned long hard = task_rlimit_max(tsk, RLIMIT_RTTIME);
|
|
/* At the hard limit, send SIGKILL. No further action. */
|
if (hard != RLIM_INFINITY &&
|
check_rlimit(rttime, hard, SIGKILL, true, true))
|
return;
|
|
/* At the soft limit, send a SIGXCPU every second */
|
if (check_rlimit(rttime, soft, SIGXCPU, true, false)) {
|
soft += USEC_PER_SEC;
|
tsk->signal->rlim[RLIMIT_RTTIME].rlim_cur = soft;
|
}
|
}
|
|
if (expiry_cache_is_inactive(pct))
|
tick_dep_clear_task(tsk, TICK_DEP_BIT_POSIX_TIMER);
|
}
|
|
static inline void stop_process_timers(struct signal_struct *sig)
|
{
|
struct posix_cputimers *pct = &sig->posix_cputimers;
|
|
/* Turn off the active flag. This is done without locking. */
|
WRITE_ONCE(pct->timers_active, false);
|
tick_dep_clear_signal(sig, TICK_DEP_BIT_POSIX_TIMER);
|
}
|
|
static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
|
u64 *expires, u64 cur_time, int signo)
|
{
|
if (!it->expires)
|
return;
|
|
if (cur_time >= it->expires) {
|
if (it->incr)
|
it->expires += it->incr;
|
else
|
it->expires = 0;
|
|
trace_itimer_expire(signo == SIGPROF ?
|
ITIMER_PROF : ITIMER_VIRTUAL,
|
task_tgid(tsk), cur_time);
|
__group_send_sig_info(signo, SEND_SIG_PRIV, tsk);
|
}
|
|
if (it->expires && it->expires < *expires)
|
*expires = it->expires;
|
}
|
|
/*
|
* Check for any per-thread CPU timers that have fired and move them
|
* off the tsk->*_timers list onto the firing list. Per-thread timers
|
* have already been taken off.
|
*/
|
static void check_process_timers(struct task_struct *tsk,
|
struct list_head *firing)
|
{
|
struct signal_struct *const sig = tsk->signal;
|
struct posix_cputimers *pct = &sig->posix_cputimers;
|
u64 samples[CPUCLOCK_MAX];
|
unsigned long soft;
|
|
/*
|
* If there are no active process wide timers (POSIX 1.b, itimers,
|
* RLIMIT_CPU) nothing to check. Also skip the process wide timer
|
* processing when there is already another task handling them.
|
*/
|
if (!READ_ONCE(pct->timers_active) || pct->expiry_active)
|
return;
|
|
/*
|
* Signify that a thread is checking for process timers.
|
* Write access to this field is protected by the sighand lock.
|
*/
|
pct->expiry_active = true;
|
|
/*
|
* Collect the current process totals. Group accounting is active
|
* so the sample can be taken directly.
|
*/
|
proc_sample_cputime_atomic(&sig->cputimer.cputime_atomic, samples);
|
collect_posix_cputimers(pct, samples, firing);
|
|
/*
|
* Check for the special case process timers.
|
*/
|
check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF],
|
&pct->bases[CPUCLOCK_PROF].nextevt,
|
samples[CPUCLOCK_PROF], SIGPROF);
|
check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT],
|
&pct->bases[CPUCLOCK_VIRT].nextevt,
|
samples[CPUCLOCK_VIRT], SIGVTALRM);
|
|
soft = task_rlimit(tsk, RLIMIT_CPU);
|
if (soft != RLIM_INFINITY) {
|
/* RLIMIT_CPU is in seconds. Samples are nanoseconds */
|
unsigned long hard = task_rlimit_max(tsk, RLIMIT_CPU);
|
u64 ptime = samples[CPUCLOCK_PROF];
|
u64 softns = (u64)soft * NSEC_PER_SEC;
|
u64 hardns = (u64)hard * NSEC_PER_SEC;
|
|
/* At the hard limit, send SIGKILL. No further action. */
|
if (hard != RLIM_INFINITY &&
|
check_rlimit(ptime, hardns, SIGKILL, false, true))
|
return;
|
|
/* At the soft limit, send a SIGXCPU every second */
|
if (check_rlimit(ptime, softns, SIGXCPU, false, false)) {
|
sig->rlim[RLIMIT_CPU].rlim_cur = soft + 1;
|
softns += NSEC_PER_SEC;
|
}
|
|
/* Update the expiry cache */
|
if (softns < pct->bases[CPUCLOCK_PROF].nextevt)
|
pct->bases[CPUCLOCK_PROF].nextevt = softns;
|
}
|
|
if (expiry_cache_is_inactive(pct))
|
stop_process_timers(sig);
|
|
pct->expiry_active = false;
|
}
|
|
/*
|
* This is called from the signal code (via posixtimer_rearm)
|
* when the last timer signal was delivered and we have to reload the timer.
|
*/
|
static void posix_cpu_timer_rearm(struct k_itimer *timer)
|
{
|
clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock);
|
struct task_struct *p;
|
struct sighand_struct *sighand;
|
unsigned long flags;
|
u64 now;
|
|
rcu_read_lock();
|
p = cpu_timer_task_rcu(timer);
|
if (!p)
|
goto out;
|
|
/* Protect timer list r/w in arm_timer() */
|
sighand = lock_task_sighand(p, &flags);
|
if (unlikely(sighand == NULL))
|
goto out;
|
|
/*
|
* Fetch the current sample and update the timer's expiry time.
|
*/
|
if (CPUCLOCK_PERTHREAD(timer->it_clock))
|
now = cpu_clock_sample(clkid, p);
|
else
|
now = cpu_clock_sample_group(clkid, p, true);
|
|
bump_cpu_timer(timer, now);
|
|
/*
|
* Now re-arm for the new expiry time.
|
*/
|
arm_timer(timer, p);
|
unlock_task_sighand(p, &flags);
|
out:
|
rcu_read_unlock();
|
}
|
|
/**
|
* task_cputimers_expired - Check whether posix CPU timers are expired
|
*
|
* @samples: Array of current samples for the CPUCLOCK clocks
|
* @pct: Pointer to a posix_cputimers container
|
*
|
* Returns true if any member of @samples is greater than the corresponding
|
* member of @pct->bases[CLK].nextevt. False otherwise
|
*/
|
static inline bool
|
task_cputimers_expired(const u64 *samples, struct posix_cputimers *pct)
|
{
|
int i;
|
|
for (i = 0; i < CPUCLOCK_MAX; i++) {
|
if (samples[i] >= pct->bases[i].nextevt)
|
return true;
|
}
|
return false;
|
}
|
|
/**
|
* fastpath_timer_check - POSIX CPU timers fast path.
|
*
|
* @tsk: The task (thread) being checked.
|
*
|
* Check the task and thread group timers. If both are zero (there are no
|
* timers set) return false. Otherwise snapshot the task and thread group
|
* timers and compare them with the corresponding expiration times. Return
|
* true if a timer has expired, else return false.
|
*/
|
static inline bool fastpath_timer_check(struct task_struct *tsk)
|
{
|
struct posix_cputimers *pct = &tsk->posix_cputimers;
|
struct signal_struct *sig;
|
|
if (!expiry_cache_is_inactive(pct)) {
|
u64 samples[CPUCLOCK_MAX];
|
|
task_sample_cputime(tsk, samples);
|
if (task_cputimers_expired(samples, pct))
|
return true;
|
}
|
|
sig = tsk->signal;
|
pct = &sig->posix_cputimers;
|
/*
|
* Check if thread group timers expired when timers are active and
|
* no other thread in the group is already handling expiry for
|
* thread group cputimers. These fields are read without the
|
* sighand lock. However, this is fine because this is meant to be
|
* a fastpath heuristic to determine whether we should try to
|
* acquire the sighand lock to handle timer expiry.
|
*
|
* In the worst case scenario, if concurrently timers_active is set
|
* or expiry_active is cleared, but the current thread doesn't see
|
* the change yet, the timer checks are delayed until the next
|
* thread in the group gets a scheduler interrupt to handle the
|
* timer. This isn't an issue in practice because these types of
|
* delays with signals actually getting sent are expected.
|
*/
|
if (READ_ONCE(pct->timers_active) && !READ_ONCE(pct->expiry_active)) {
|
u64 samples[CPUCLOCK_MAX];
|
|
proc_sample_cputime_atomic(&sig->cputimer.cputime_atomic,
|
samples);
|
|
if (task_cputimers_expired(samples, pct))
|
return true;
|
}
|
|
if (dl_task(tsk) && tsk->dl.dl_overrun)
|
return true;
|
|
return false;
|
}
|
|
static void handle_posix_cpu_timers(struct task_struct *tsk);
|
|
#ifdef CONFIG_POSIX_CPU_TIMERS_TASK_WORK
|
static void posix_cpu_timers_work(struct callback_head *work)
|
{
|
handle_posix_cpu_timers(current);
|
}
|
|
/*
|
* Clear existing posix CPU timers task work.
|
*/
|
void clear_posix_cputimers_work(struct task_struct *p)
|
{
|
/*
|
* A copied work entry from the old task is not meaningful, clear it.
|
* N.B. init_task_work will not do this.
|
*/
|
memset(&p->posix_cputimers_work.work, 0,
|
sizeof(p->posix_cputimers_work.work));
|
init_task_work(&p->posix_cputimers_work.work,
|
posix_cpu_timers_work);
|
p->posix_cputimers_work.scheduled = false;
|
}
|
|
/*
|
* Initialize posix CPU timers task work in init task. Out of line to
|
* keep the callback static and to avoid header recursion hell.
|
*/
|
void __init posix_cputimers_init_work(void)
|
{
|
clear_posix_cputimers_work(current);
|
}
|
|
/*
|
* Note: All operations on tsk->posix_cputimer_work.scheduled happen either
|
* in hard interrupt context or in task context with interrupts
|
* disabled. Aside of that the writer/reader interaction is always in the
|
* context of the current task, which means they are strict per CPU.
|
*/
|
static inline bool posix_cpu_timers_work_scheduled(struct task_struct *tsk)
|
{
|
return tsk->posix_cputimers_work.scheduled;
|
}
|
|
static inline void __run_posix_cpu_timers(struct task_struct *tsk)
|
{
|
if (WARN_ON_ONCE(tsk->posix_cputimers_work.scheduled))
|
return;
|
|
/* Schedule task work to actually expire the timers */
|
tsk->posix_cputimers_work.scheduled = true;
|
task_work_add(tsk, &tsk->posix_cputimers_work.work, TWA_RESUME);
|
}
|
|
static inline bool posix_cpu_timers_enable_work(struct task_struct *tsk,
|
unsigned long start)
|
{
|
bool ret = true;
|
|
/*
|
* On !RT kernels interrupts are disabled while collecting expired
|
* timers, so no tick can happen and the fast path check can be
|
* reenabled without further checks.
|
*/
|
if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
|
tsk->posix_cputimers_work.scheduled = false;
|
return true;
|
}
|
|
/*
|
* On RT enabled kernels ticks can happen while the expired timers
|
* are collected under sighand lock. But any tick which observes
|
* the CPUTIMERS_WORK_SCHEDULED bit set, does not run the fastpath
|
* checks. So reenabling the tick work has do be done carefully:
|
*
|
* Disable interrupts and run the fast path check if jiffies have
|
* advanced since the collecting of expired timers started. If
|
* jiffies have not advanced or the fast path check did not find
|
* newly expired timers, reenable the fast path check in the timer
|
* interrupt. If there are newly expired timers, return false and
|
* let the collection loop repeat.
|
*/
|
local_irq_disable();
|
if (start != jiffies && fastpath_timer_check(tsk))
|
ret = false;
|
else
|
tsk->posix_cputimers_work.scheduled = false;
|
local_irq_enable();
|
|
return ret;
|
}
|
#else /* CONFIG_POSIX_CPU_TIMERS_TASK_WORK */
|
static inline void __run_posix_cpu_timers(struct task_struct *tsk)
|
{
|
lockdep_posixtimer_enter();
|
handle_posix_cpu_timers(tsk);
|
lockdep_posixtimer_exit();
|
}
|
|
static inline bool posix_cpu_timers_work_scheduled(struct task_struct *tsk)
|
{
|
return false;
|
}
|
|
static inline bool posix_cpu_timers_enable_work(struct task_struct *tsk,
|
unsigned long start)
|
{
|
return true;
|
}
|
#endif /* CONFIG_POSIX_CPU_TIMERS_TASK_WORK */
|
|
static void handle_posix_cpu_timers(struct task_struct *tsk)
|
{
|
struct k_itimer *timer, *next;
|
unsigned long flags, start;
|
LIST_HEAD(firing);
|
|
if (!lock_task_sighand(tsk, &flags))
|
return;
|
|
do {
|
/*
|
* On RT locking sighand lock does not disable interrupts,
|
* so this needs to be careful vs. ticks. Store the current
|
* jiffies value.
|
*/
|
start = READ_ONCE(jiffies);
|
barrier();
|
|
/*
|
* Here we take off tsk->signal->cpu_timers[N] and
|
* tsk->cpu_timers[N] all the timers that are firing, and
|
* put them on the firing list.
|
*/
|
check_thread_timers(tsk, &firing);
|
|
check_process_timers(tsk, &firing);
|
|
/*
|
* The above timer checks have updated the exipry cache and
|
* because nothing can have queued or modified timers after
|
* sighand lock was taken above it is guaranteed to be
|
* consistent. So the next timer interrupt fastpath check
|
* will find valid data.
|
*
|
* If timer expiry runs in the timer interrupt context then
|
* the loop is not relevant as timers will be directly
|
* expired in interrupt context. The stub function below
|
* returns always true which allows the compiler to
|
* optimize the loop out.
|
*
|
* If timer expiry is deferred to task work context then
|
* the following rules apply:
|
*
|
* - On !RT kernels no tick can have happened on this CPU
|
* after sighand lock was acquired because interrupts are
|
* disabled. So reenabling task work before dropping
|
* sighand lock and reenabling interrupts is race free.
|
*
|
* - On RT kernels ticks might have happened but the tick
|
* work ignored posix CPU timer handling because the
|
* CPUTIMERS_WORK_SCHEDULED bit is set. Reenabling work
|
* must be done very carefully including a check whether
|
* ticks have happened since the start of the timer
|
* expiry checks. posix_cpu_timers_enable_work() takes
|
* care of that and eventually lets the expiry checks
|
* run again.
|
*/
|
} while (!posix_cpu_timers_enable_work(tsk, start));
|
|
/*
|
* We must release sighand lock before taking any timer's lock.
|
* There is a potential race with timer deletion here, as the
|
* siglock now protects our private firing list. We have set
|
* the firing flag in each timer, so that a deletion attempt
|
* that gets the timer lock before we do will give it up and
|
* spin until we've taken care of that timer below.
|
*/
|
unlock_task_sighand(tsk, &flags);
|
|
/*
|
* Now that all the timers on our list have the firing flag,
|
* no one will touch their list entries but us. We'll take
|
* each timer's lock before clearing its firing flag, so no
|
* timer call will interfere.
|
*/
|
list_for_each_entry_safe(timer, next, &firing, it.cpu.elist) {
|
int cpu_firing;
|
|
/*
|
* spin_lock() is sufficient here even independent of the
|
* expiry context. If expiry happens in hard interrupt
|
* context it's obvious. For task work context it's safe
|
* because all other operations on timer::it_lock happen in
|
* task context (syscall or exit).
|
*/
|
spin_lock(&timer->it_lock);
|
list_del_init(&timer->it.cpu.elist);
|
cpu_firing = timer->it.cpu.firing;
|
timer->it.cpu.firing = 0;
|
/*
|
* The firing flag is -1 if we collided with a reset
|
* of the timer, which already reported this
|
* almost-firing as an overrun. So don't generate an event.
|
*/
|
if (likely(cpu_firing >= 0))
|
cpu_timer_fire(timer);
|
spin_unlock(&timer->it_lock);
|
}
|
}
|
|
/*
|
* This is called from the timer interrupt handler. The irq handler has
|
* already updated our counts. We need to check if any timers fire now.
|
* Interrupts are disabled.
|
*/
|
void run_posix_cpu_timers(void)
|
{
|
struct task_struct *tsk = current;
|
|
lockdep_assert_irqs_disabled();
|
|
/*
|
* If the actual expiry is deferred to task work context and the
|
* work is already scheduled there is no point to do anything here.
|
*/
|
if (posix_cpu_timers_work_scheduled(tsk))
|
return;
|
|
/*
|
* The fast path checks that there are no expired thread or thread
|
* group timers. If that's so, just return.
|
*/
|
if (!fastpath_timer_check(tsk))
|
return;
|
|
__run_posix_cpu_timers(tsk);
|
}
|
|
/*
|
* Set one of the process-wide special case CPU timers or RLIMIT_CPU.
|
* The tsk->sighand->siglock must be held by the caller.
|
*/
|
void set_process_cpu_timer(struct task_struct *tsk, unsigned int clkid,
|
u64 *newval, u64 *oldval)
|
{
|
u64 now, *nextevt;
|
|
if (WARN_ON_ONCE(clkid >= CPUCLOCK_SCHED))
|
return;
|
|
nextevt = &tsk->signal->posix_cputimers.bases[clkid].nextevt;
|
now = cpu_clock_sample_group(clkid, tsk, true);
|
|
if (oldval) {
|
/*
|
* We are setting itimer. The *oldval is absolute and we update
|
* it to be relative, *newval argument is relative and we update
|
* it to be absolute.
|
*/
|
if (*oldval) {
|
if (*oldval <= now) {
|
/* Just about to fire. */
|
*oldval = TICK_NSEC;
|
} else {
|
*oldval -= now;
|
}
|
}
|
|
if (!*newval)
|
return;
|
*newval += now;
|
}
|
|
/*
|
* Update expiration cache if this is the earliest timer. CPUCLOCK_PROF
|
* expiry cache is also used by RLIMIT_CPU!.
|
*/
|
if (*newval < *nextevt)
|
*nextevt = *newval;
|
|
tick_dep_set_signal(tsk->signal, TICK_DEP_BIT_POSIX_TIMER);
|
}
|
|
static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
|
const struct timespec64 *rqtp)
|
{
|
struct itimerspec64 it;
|
struct k_itimer timer;
|
u64 expires;
|
int error;
|
|
/*
|
* Set up a temporary timer and then wait for it to go off.
|
*/
|
memset(&timer, 0, sizeof timer);
|
spin_lock_init(&timer.it_lock);
|
timer.it_clock = which_clock;
|
timer.it_overrun = -1;
|
error = posix_cpu_timer_create(&timer);
|
timer.it_process = current;
|
|
if (!error) {
|
static struct itimerspec64 zero_it;
|
struct restart_block *restart;
|
|
memset(&it, 0, sizeof(it));
|
it.it_value = *rqtp;
|
|
spin_lock_irq(&timer.it_lock);
|
error = posix_cpu_timer_set(&timer, flags, &it, NULL);
|
if (error) {
|
spin_unlock_irq(&timer.it_lock);
|
return error;
|
}
|
|
while (!signal_pending(current)) {
|
if (!cpu_timer_getexpires(&timer.it.cpu)) {
|
/*
|
* Our timer fired and was reset, below
|
* deletion can not fail.
|
*/
|
posix_cpu_timer_del(&timer);
|
spin_unlock_irq(&timer.it_lock);
|
return 0;
|
}
|
|
/*
|
* Block until cpu_timer_fire (or a signal) wakes us.
|
*/
|
__set_current_state(TASK_INTERRUPTIBLE);
|
spin_unlock_irq(&timer.it_lock);
|
schedule();
|
spin_lock_irq(&timer.it_lock);
|
}
|
|
/*
|
* We were interrupted by a signal.
|
*/
|
expires = cpu_timer_getexpires(&timer.it.cpu);
|
error = posix_cpu_timer_set(&timer, 0, &zero_it, &it);
|
if (!error) {
|
/*
|
* Timer is now unarmed, deletion can not fail.
|
*/
|
posix_cpu_timer_del(&timer);
|
}
|
spin_unlock_irq(&timer.it_lock);
|
|
while (error == TIMER_RETRY) {
|
/*
|
* We need to handle case when timer was or is in the
|
* middle of firing. In other cases we already freed
|
* resources.
|
*/
|
spin_lock_irq(&timer.it_lock);
|
error = posix_cpu_timer_del(&timer);
|
spin_unlock_irq(&timer.it_lock);
|
}
|
|
if ((it.it_value.tv_sec | it.it_value.tv_nsec) == 0) {
|
/*
|
* It actually did fire already.
|
*/
|
return 0;
|
}
|
|
error = -ERESTART_RESTARTBLOCK;
|
/*
|
* Report back to the user the time still remaining.
|
*/
|
restart = ¤t->restart_block;
|
restart->nanosleep.expires = expires;
|
if (restart->nanosleep.type != TT_NONE)
|
error = nanosleep_copyout(restart, &it.it_value);
|
}
|
|
return error;
|
}
|
|
static long posix_cpu_nsleep_restart(struct restart_block *restart_block);
|
|
static int posix_cpu_nsleep(const clockid_t which_clock, int flags,
|
const struct timespec64 *rqtp)
|
{
|
struct restart_block *restart_block = ¤t->restart_block;
|
int error;
|
|
/*
|
* Diagnose required errors first.
|
*/
|
if (CPUCLOCK_PERTHREAD(which_clock) &&
|
(CPUCLOCK_PID(which_clock) == 0 ||
|
CPUCLOCK_PID(which_clock) == task_pid_vnr(current)))
|
return -EINVAL;
|
|
error = do_cpu_nanosleep(which_clock, flags, rqtp);
|
|
if (error == -ERESTART_RESTARTBLOCK) {
|
|
if (flags & TIMER_ABSTIME)
|
return -ERESTARTNOHAND;
|
|
restart_block->nanosleep.clockid = which_clock;
|
set_restart_fn(restart_block, posix_cpu_nsleep_restart);
|
}
|
return error;
|
}
|
|
static long posix_cpu_nsleep_restart(struct restart_block *restart_block)
|
{
|
clockid_t which_clock = restart_block->nanosleep.clockid;
|
struct timespec64 t;
|
|
t = ns_to_timespec64(restart_block->nanosleep.expires);
|
|
return do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t);
|
}
|
|
#define PROCESS_CLOCK make_process_cpuclock(0, CPUCLOCK_SCHED)
|
#define THREAD_CLOCK make_thread_cpuclock(0, CPUCLOCK_SCHED)
|
|
static int process_cpu_clock_getres(const clockid_t which_clock,
|
struct timespec64 *tp)
|
{
|
return posix_cpu_clock_getres(PROCESS_CLOCK, tp);
|
}
|
static int process_cpu_clock_get(const clockid_t which_clock,
|
struct timespec64 *tp)
|
{
|
return posix_cpu_clock_get(PROCESS_CLOCK, tp);
|
}
|
static int process_cpu_timer_create(struct k_itimer *timer)
|
{
|
timer->it_clock = PROCESS_CLOCK;
|
return posix_cpu_timer_create(timer);
|
}
|
static int process_cpu_nsleep(const clockid_t which_clock, int flags,
|
const struct timespec64 *rqtp)
|
{
|
return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp);
|
}
|
static int thread_cpu_clock_getres(const clockid_t which_clock,
|
struct timespec64 *tp)
|
{
|
return posix_cpu_clock_getres(THREAD_CLOCK, tp);
|
}
|
static int thread_cpu_clock_get(const clockid_t which_clock,
|
struct timespec64 *tp)
|
{
|
return posix_cpu_clock_get(THREAD_CLOCK, tp);
|
}
|
static int thread_cpu_timer_create(struct k_itimer *timer)
|
{
|
timer->it_clock = THREAD_CLOCK;
|
return posix_cpu_timer_create(timer);
|
}
|
|
const struct k_clock clock_posix_cpu = {
|
.clock_getres = posix_cpu_clock_getres,
|
.clock_set = posix_cpu_clock_set,
|
.clock_get_timespec = posix_cpu_clock_get,
|
.timer_create = posix_cpu_timer_create,
|
.nsleep = posix_cpu_nsleep,
|
.timer_set = posix_cpu_timer_set,
|
.timer_del = posix_cpu_timer_del,
|
.timer_get = posix_cpu_timer_get,
|
.timer_rearm = posix_cpu_timer_rearm,
|
};
|
|
const struct k_clock clock_process = {
|
.clock_getres = process_cpu_clock_getres,
|
.clock_get_timespec = process_cpu_clock_get,
|
.timer_create = process_cpu_timer_create,
|
.nsleep = process_cpu_nsleep,
|
};
|
|
const struct k_clock clock_thread = {
|
.clock_getres = thread_cpu_clock_getres,
|
.clock_get_timespec = thread_cpu_clock_get,
|
.timer_create = thread_cpu_timer_create,
|
};
|
