mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 01:10:04 +00:00
![Thomas Gleixner](/assets/img/avatar_default.png)
A recent commit added extra printks for CPU/RT limits. This can result in
excessive spam in dmesg.
Make the printks conditional on print_fatal_signals.
Fixes: e7ea7c9806
("rlimits: Print more information when CPU/RT limits are exceeded")
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arun Raghavan <arun@arunraghavan.net>
1456 lines
38 KiB
C
1456 lines
38 KiB
C
/*
|
|
* Implement CPU time clocks for the POSIX clock interface.
|
|
*/
|
|
|
|
#include <linux/sched/signal.h>
|
|
#include <linux/sched/cputime.h>
|
|
#include <linux/posix-timers.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/math64.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/kernel_stat.h>
|
|
#include <trace/events/timer.h>
|
|
#include <linux/tick.h>
|
|
#include <linux/workqueue.h>
|
|
|
|
/*
|
|
* Called after updating RLIMIT_CPU to run cpu timer and update
|
|
* tsk->signal->cputime_expires expiration cache if necessary. Needs
|
|
* siglock protection since other code may update expiration cache as
|
|
* well.
|
|
*/
|
|
void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new)
|
|
{
|
|
u64 nsecs = rlim_new * NSEC_PER_SEC;
|
|
|
|
spin_lock_irq(&task->sighand->siglock);
|
|
set_process_cpu_timer(task, CPUCLOCK_PROF, &nsecs, NULL);
|
|
spin_unlock_irq(&task->sighand->siglock);
|
|
}
|
|
|
|
static int check_clock(const clockid_t which_clock)
|
|
{
|
|
int error = 0;
|
|
struct task_struct *p;
|
|
const pid_t pid = CPUCLOCK_PID(which_clock);
|
|
|
|
if (CPUCLOCK_WHICH(which_clock) >= CPUCLOCK_MAX)
|
|
return -EINVAL;
|
|
|
|
if (pid == 0)
|
|
return 0;
|
|
|
|
rcu_read_lock();
|
|
p = find_task_by_vpid(pid);
|
|
if (!p || !(CPUCLOCK_PERTHREAD(which_clock) ?
|
|
same_thread_group(p, current) : has_group_leader_pid(p))) {
|
|
error = -EINVAL;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Update expiry time from increment, and increase overrun count,
|
|
* given the current clock sample.
|
|
*/
|
|
static void bump_cpu_timer(struct k_itimer *timer, u64 now)
|
|
{
|
|
int i;
|
|
u64 delta, incr;
|
|
|
|
if (timer->it.cpu.incr == 0)
|
|
return;
|
|
|
|
if (now < timer->it.cpu.expires)
|
|
return;
|
|
|
|
incr = timer->it.cpu.incr;
|
|
delta = now + incr - timer->it.cpu.expires;
|
|
|
|
/* Don't use (incr*2 < delta), incr*2 might overflow. */
|
|
for (i = 0; incr < delta - incr; i++)
|
|
incr = incr << 1;
|
|
|
|
for (; i >= 0; incr >>= 1, i--) {
|
|
if (delta < incr)
|
|
continue;
|
|
|
|
timer->it.cpu.expires += incr;
|
|
timer->it_overrun += 1 << i;
|
|
delta -= incr;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* task_cputime_zero - Check a task_cputime struct for all zero fields.
|
|
*
|
|
* @cputime: The struct to compare.
|
|
*
|
|
* Checks @cputime to see if all fields are zero. Returns true if all fields
|
|
* are zero, false if any field is nonzero.
|
|
*/
|
|
static inline int task_cputime_zero(const struct task_cputime *cputime)
|
|
{
|
|
if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static inline u64 prof_ticks(struct task_struct *p)
|
|
{
|
|
u64 utime, stime;
|
|
|
|
task_cputime(p, &utime, &stime);
|
|
|
|
return utime + stime;
|
|
}
|
|
static inline u64 virt_ticks(struct task_struct *p)
|
|
{
|
|
u64 utime, stime;
|
|
|
|
task_cputime(p, &utime, &stime);
|
|
|
|
return utime;
|
|
}
|
|
|
|
static int
|
|
posix_cpu_clock_getres(const clockid_t which_clock, struct timespec64 *tp)
|
|
{
|
|
int error = check_clock(which_clock);
|
|
if (!error) {
|
|
tp->tv_sec = 0;
|
|
tp->tv_nsec = ((NSEC_PER_SEC + HZ - 1) / HZ);
|
|
if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
|
|
/*
|
|
* If sched_clock is using a cycle counter, we
|
|
* don't have any idea of its true resolution
|
|
* exported, but it is much more than 1s/HZ.
|
|
*/
|
|
tp->tv_nsec = 1;
|
|
}
|
|
}
|
|
return error;
|
|
}
|
|
|
|
static int
|
|
posix_cpu_clock_set(const clockid_t which_clock, const struct timespec64 *tp)
|
|
{
|
|
/*
|
|
* You can never reset a CPU clock, but we check for other errors
|
|
* in the call before failing with EPERM.
|
|
*/
|
|
int error = check_clock(which_clock);
|
|
if (error == 0) {
|
|
error = -EPERM;
|
|
}
|
|
return error;
|
|
}
|
|
|
|
|
|
/*
|
|
* Sample a per-thread clock for the given task.
|
|
*/
|
|
static int cpu_clock_sample(const clockid_t which_clock,
|
|
struct task_struct *p, u64 *sample)
|
|
{
|
|
switch (CPUCLOCK_WHICH(which_clock)) {
|
|
default:
|
|
return -EINVAL;
|
|
case CPUCLOCK_PROF:
|
|
*sample = prof_ticks(p);
|
|
break;
|
|
case CPUCLOCK_VIRT:
|
|
*sample = virt_ticks(p);
|
|
break;
|
|
case CPUCLOCK_SCHED:
|
|
*sample = task_sched_runtime(p);
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Set cputime to sum_cputime if sum_cputime > cputime. Use cmpxchg
|
|
* to avoid race conditions with concurrent updates to cputime.
|
|
*/
|
|
static inline void __update_gt_cputime(atomic64_t *cputime, u64 sum_cputime)
|
|
{
|
|
u64 curr_cputime;
|
|
retry:
|
|
curr_cputime = atomic64_read(cputime);
|
|
if (sum_cputime > curr_cputime) {
|
|
if (atomic64_cmpxchg(cputime, curr_cputime, sum_cputime) != curr_cputime)
|
|
goto retry;
|
|
}
|
|
}
|
|
|
|
static void update_gt_cputime(struct task_cputime_atomic *cputime_atomic, struct task_cputime *sum)
|
|
{
|
|
__update_gt_cputime(&cputime_atomic->utime, sum->utime);
|
|
__update_gt_cputime(&cputime_atomic->stime, sum->stime);
|
|
__update_gt_cputime(&cputime_atomic->sum_exec_runtime, sum->sum_exec_runtime);
|
|
}
|
|
|
|
/* Sample task_cputime_atomic values in "atomic_timers", store results in "times". */
|
|
static inline void sample_cputime_atomic(struct task_cputime *times,
|
|
struct task_cputime_atomic *atomic_times)
|
|
{
|
|
times->utime = atomic64_read(&atomic_times->utime);
|
|
times->stime = atomic64_read(&atomic_times->stime);
|
|
times->sum_exec_runtime = atomic64_read(&atomic_times->sum_exec_runtime);
|
|
}
|
|
|
|
void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
|
|
{
|
|
struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
|
|
struct task_cputime sum;
|
|
|
|
/* Check if cputimer isn't running. This is accessed without locking. */
|
|
if (!READ_ONCE(cputimer->running)) {
|
|
/*
|
|
* The POSIX timer interface allows for absolute time expiry
|
|
* values through the TIMER_ABSTIME flag, therefore we have
|
|
* to synchronize the timer to the clock every time we start it.
|
|
*/
|
|
thread_group_cputime(tsk, &sum);
|
|
update_gt_cputime(&cputimer->cputime_atomic, &sum);
|
|
|
|
/*
|
|
* We're setting cputimer->running without a lock. Ensure
|
|
* this only gets written to in one operation. We set
|
|
* running after update_gt_cputime() as a small optimization,
|
|
* but barriers are not required because update_gt_cputime()
|
|
* can handle concurrent updates.
|
|
*/
|
|
WRITE_ONCE(cputimer->running, true);
|
|
}
|
|
sample_cputime_atomic(times, &cputimer->cputime_atomic);
|
|
}
|
|
|
|
/*
|
|
* Sample a process (thread group) clock for the given group_leader task.
|
|
* Must be called with task sighand lock held for safe while_each_thread()
|
|
* traversal.
|
|
*/
|
|
static int cpu_clock_sample_group(const clockid_t which_clock,
|
|
struct task_struct *p,
|
|
u64 *sample)
|
|
{
|
|
struct task_cputime cputime;
|
|
|
|
switch (CPUCLOCK_WHICH(which_clock)) {
|
|
default:
|
|
return -EINVAL;
|
|
case CPUCLOCK_PROF:
|
|
thread_group_cputime(p, &cputime);
|
|
*sample = cputime.utime + cputime.stime;
|
|
break;
|
|
case CPUCLOCK_VIRT:
|
|
thread_group_cputime(p, &cputime);
|
|
*sample = cputime.utime;
|
|
break;
|
|
case CPUCLOCK_SCHED:
|
|
thread_group_cputime(p, &cputime);
|
|
*sample = cputime.sum_exec_runtime;
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int posix_cpu_clock_get_task(struct task_struct *tsk,
|
|
const clockid_t which_clock,
|
|
struct timespec64 *tp)
|
|
{
|
|
int err = -EINVAL;
|
|
u64 rtn;
|
|
|
|
if (CPUCLOCK_PERTHREAD(which_clock)) {
|
|
if (same_thread_group(tsk, current))
|
|
err = cpu_clock_sample(which_clock, tsk, &rtn);
|
|
} else {
|
|
if (tsk == current || thread_group_leader(tsk))
|
|
err = cpu_clock_sample_group(which_clock, tsk, &rtn);
|
|
}
|
|
|
|
if (!err)
|
|
*tp = ns_to_timespec64(rtn);
|
|
|
|
return err;
|
|
}
|
|
|
|
|
|
static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec64 *tp)
|
|
{
|
|
const pid_t pid = CPUCLOCK_PID(which_clock);
|
|
int err = -EINVAL;
|
|
|
|
if (pid == 0) {
|
|
/*
|
|
* Special case constant value for our own clocks.
|
|
* We don't have to do any lookup to find ourselves.
|
|
*/
|
|
err = posix_cpu_clock_get_task(current, which_clock, tp);
|
|
} else {
|
|
/*
|
|
* Find the given PID, and validate that the caller
|
|
* should be able to see it.
|
|
*/
|
|
struct task_struct *p;
|
|
rcu_read_lock();
|
|
p = find_task_by_vpid(pid);
|
|
if (p)
|
|
err = posix_cpu_clock_get_task(p, which_clock, tp);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
static int posix_cpu_timer_create(struct k_itimer *new_timer)
|
|
{
|
|
int ret = 0;
|
|
const pid_t pid = CPUCLOCK_PID(new_timer->it_clock);
|
|
struct task_struct *p;
|
|
|
|
if (CPUCLOCK_WHICH(new_timer->it_clock) >= CPUCLOCK_MAX)
|
|
return -EINVAL;
|
|
|
|
INIT_LIST_HEAD(&new_timer->it.cpu.entry);
|
|
|
|
rcu_read_lock();
|
|
if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) {
|
|
if (pid == 0) {
|
|
p = current;
|
|
} else {
|
|
p = find_task_by_vpid(pid);
|
|
if (p && !same_thread_group(p, current))
|
|
p = NULL;
|
|
}
|
|
} else {
|
|
if (pid == 0) {
|
|
p = current->group_leader;
|
|
} else {
|
|
p = find_task_by_vpid(pid);
|
|
if (p && !has_group_leader_pid(p))
|
|
p = NULL;
|
|
}
|
|
}
|
|
new_timer->it.cpu.task = p;
|
|
if (p) {
|
|
get_task_struct(p);
|
|
} else {
|
|
ret = -EINVAL;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
int ret = 0;
|
|
unsigned long flags;
|
|
struct sighand_struct *sighand;
|
|
struct task_struct *p = timer->it.cpu.task;
|
|
|
|
WARN_ON_ONCE(p == NULL);
|
|
|
|
/*
|
|
* 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)) {
|
|
/*
|
|
* We raced with the reaping of the task.
|
|
* The deletion should have cleared us off the list.
|
|
*/
|
|
WARN_ON_ONCE(!list_empty(&timer->it.cpu.entry));
|
|
} else {
|
|
if (timer->it.cpu.firing)
|
|
ret = TIMER_RETRY;
|
|
else
|
|
list_del(&timer->it.cpu.entry);
|
|
|
|
unlock_task_sighand(p, &flags);
|
|
}
|
|
|
|
if (!ret)
|
|
put_task_struct(p);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void cleanup_timers_list(struct list_head *head)
|
|
{
|
|
struct cpu_timer_list *timer, *next;
|
|
|
|
list_for_each_entry_safe(timer, next, head, entry)
|
|
list_del_init(&timer->entry);
|
|
}
|
|
|
|
/*
|
|
* Clean out CPU timers still ticking when a thread exited. The task
|
|
* pointer is cleared, and the expiry time is replaced with the residual
|
|
* time for later timer_gettime calls to return.
|
|
* This must be called with the siglock held.
|
|
*/
|
|
static void cleanup_timers(struct list_head *head)
|
|
{
|
|
cleanup_timers_list(head);
|
|
cleanup_timers_list(++head);
|
|
cleanup_timers_list(++head);
|
|
}
|
|
|
|
/*
|
|
* 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->cpu_timers);
|
|
}
|
|
void posix_cpu_timers_exit_group(struct task_struct *tsk)
|
|
{
|
|
cleanup_timers(tsk->signal->cpu_timers);
|
|
}
|
|
|
|
static inline int expires_gt(u64 expires, u64 new_exp)
|
|
{
|
|
return expires == 0 || expires > new_exp;
|
|
}
|
|
|
|
/*
|
|
* 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 = timer->it.cpu.task;
|
|
struct list_head *head, *listpos;
|
|
struct task_cputime *cputime_expires;
|
|
struct cpu_timer_list *const nt = &timer->it.cpu;
|
|
struct cpu_timer_list *next;
|
|
|
|
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
|
|
head = p->cpu_timers;
|
|
cputime_expires = &p->cputime_expires;
|
|
} else {
|
|
head = p->signal->cpu_timers;
|
|
cputime_expires = &p->signal->cputime_expires;
|
|
}
|
|
head += CPUCLOCK_WHICH(timer->it_clock);
|
|
|
|
listpos = head;
|
|
list_for_each_entry(next, head, entry) {
|
|
if (nt->expires < next->expires)
|
|
break;
|
|
listpos = &next->entry;
|
|
}
|
|
list_add(&nt->entry, listpos);
|
|
|
|
if (listpos == head) {
|
|
u64 exp = nt->expires;
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
|
|
switch (CPUCLOCK_WHICH(timer->it_clock)) {
|
|
case CPUCLOCK_PROF:
|
|
if (expires_gt(cputime_expires->prof_exp, exp))
|
|
cputime_expires->prof_exp = exp;
|
|
break;
|
|
case CPUCLOCK_VIRT:
|
|
if (expires_gt(cputime_expires->virt_exp, exp))
|
|
cputime_expires->virt_exp = exp;
|
|
break;
|
|
case CPUCLOCK_SCHED:
|
|
if (expires_gt(cputime_expires->sched_exp, exp))
|
|
cputime_expires->sched_exp = exp;
|
|
break;
|
|
}
|
|
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)
|
|
{
|
|
if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
|
|
/*
|
|
* User don't want any signal.
|
|
*/
|
|
timer->it.cpu.expires = 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);
|
|
timer->it.cpu.expires = 0;
|
|
} else if (timer->it.cpu.incr == 0) {
|
|
/*
|
|
* One-shot timer. Clear it as soon as it's fired.
|
|
*/
|
|
posix_timer_event(timer, 0);
|
|
timer->it.cpu.expires = 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_schedule(timer);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Sample a process (thread group) timer for the given group_leader task.
|
|
* Must be called with task sighand lock held for safe while_each_thread()
|
|
* traversal.
|
|
*/
|
|
static int cpu_timer_sample_group(const clockid_t which_clock,
|
|
struct task_struct *p, u64 *sample)
|
|
{
|
|
struct task_cputime cputime;
|
|
|
|
thread_group_cputimer(p, &cputime);
|
|
switch (CPUCLOCK_WHICH(which_clock)) {
|
|
default:
|
|
return -EINVAL;
|
|
case CPUCLOCK_PROF:
|
|
*sample = cputime.utime + cputime.stime;
|
|
break;
|
|
case CPUCLOCK_VIRT:
|
|
*sample = cputime.utime;
|
|
break;
|
|
case CPUCLOCK_SCHED:
|
|
*sample = cputime.sum_exec_runtime;
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
unsigned long flags;
|
|
struct sighand_struct *sighand;
|
|
struct task_struct *p = timer->it.cpu.task;
|
|
u64 old_expires, new_expires, old_incr, val;
|
|
int ret;
|
|
|
|
WARN_ON_ONCE(p == NULL);
|
|
|
|
new_expires = timespec64_to_ns(&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)) {
|
|
return -ESRCH;
|
|
}
|
|
|
|
/*
|
|
* Disarm any old timer after extracting its expiry time.
|
|
*/
|
|
WARN_ON_ONCE(!irqs_disabled());
|
|
|
|
ret = 0;
|
|
old_incr = timer->it.cpu.incr;
|
|
old_expires = timer->it.cpu.expires;
|
|
if (unlikely(timer->it.cpu.firing)) {
|
|
timer->it.cpu.firing = -1;
|
|
ret = TIMER_RETRY;
|
|
} else
|
|
list_del_init(&timer->it.cpu.entry);
|
|
|
|
/*
|
|
* 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)) {
|
|
cpu_clock_sample(timer->it_clock, p, &val);
|
|
} else {
|
|
cpu_timer_sample_group(timer->it_clock, p, &val);
|
|
}
|
|
|
|
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.
|
|
*/
|
|
bump_cpu_timer(timer, val);
|
|
if (val < timer->it.cpu.expires) {
|
|
old_expires = timer->it.cpu.expires - 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).
|
|
*/
|
|
timer->it.cpu.expires = new_expires;
|
|
if (new_expires != 0 && val < new_expires) {
|
|
arm_timer(timer);
|
|
}
|
|
|
|
unlock_task_sighand(p, &flags);
|
|
/*
|
|
* Install the new reload setting, and
|
|
* set up the signal and overrun bookkeeping.
|
|
*/
|
|
timer->it.cpu.incr = timespec64_to_ns(&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:
|
|
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)
|
|
{
|
|
u64 now;
|
|
struct task_struct *p = timer->it.cpu.task;
|
|
|
|
WARN_ON_ONCE(p == NULL);
|
|
|
|
/*
|
|
* Easy part: convert the reload time.
|
|
*/
|
|
itp->it_interval = ns_to_timespec64(timer->it.cpu.incr);
|
|
|
|
if (timer->it.cpu.expires == 0) { /* Timer not armed at all. */
|
|
itp->it_value.tv_sec = itp->it_value.tv_nsec = 0;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Sample the clock to take the difference with the expiry time.
|
|
*/
|
|
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
|
|
cpu_clock_sample(timer->it_clock, p, &now);
|
|
} else {
|
|
struct sighand_struct *sighand;
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* Protect against sighand release/switch in exit/exec and
|
|
* also make timer sampling safe if it ends up calling
|
|
* thread_group_cputime().
|
|
*/
|
|
sighand = lock_task_sighand(p, &flags);
|
|
if (unlikely(sighand == NULL)) {
|
|
/*
|
|
* The process has been reaped.
|
|
* We can't even collect a sample any more.
|
|
* Call the timer disarmed, nothing else to do.
|
|
*/
|
|
timer->it.cpu.expires = 0;
|
|
itp->it_value = ns_to_timespec64(timer->it.cpu.expires);
|
|
return;
|
|
} else {
|
|
cpu_timer_sample_group(timer->it_clock, p, &now);
|
|
unlock_task_sighand(p, &flags);
|
|
}
|
|
}
|
|
|
|
if (now < timer->it.cpu.expires) {
|
|
itp->it_value = ns_to_timespec64(timer->it.cpu.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;
|
|
}
|
|
}
|
|
|
|
static unsigned long long
|
|
check_timers_list(struct list_head *timers,
|
|
struct list_head *firing,
|
|
unsigned long long curr)
|
|
{
|
|
int maxfire = 20;
|
|
|
|
while (!list_empty(timers)) {
|
|
struct cpu_timer_list *t;
|
|
|
|
t = list_first_entry(timers, struct cpu_timer_list, entry);
|
|
|
|
if (!--maxfire || curr < t->expires)
|
|
return t->expires;
|
|
|
|
t->firing = 1;
|
|
list_move_tail(&t->entry, firing);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* 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 list_head *timers = tsk->cpu_timers;
|
|
struct signal_struct *const sig = tsk->signal;
|
|
struct task_cputime *tsk_expires = &tsk->cputime_expires;
|
|
u64 expires;
|
|
unsigned long soft;
|
|
|
|
/*
|
|
* If cputime_expires is zero, then there are no active
|
|
* per thread CPU timers.
|
|
*/
|
|
if (task_cputime_zero(&tsk->cputime_expires))
|
|
return;
|
|
|
|
expires = check_timers_list(timers, firing, prof_ticks(tsk));
|
|
tsk_expires->prof_exp = expires;
|
|
|
|
expires = check_timers_list(++timers, firing, virt_ticks(tsk));
|
|
tsk_expires->virt_exp = expires;
|
|
|
|
tsk_expires->sched_exp = check_timers_list(++timers, firing,
|
|
tsk->se.sum_exec_runtime);
|
|
|
|
/*
|
|
* Check for the special case thread timers.
|
|
*/
|
|
soft = READ_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_cur);
|
|
if (soft != RLIM_INFINITY) {
|
|
unsigned long hard =
|
|
READ_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_max);
|
|
|
|
if (hard != RLIM_INFINITY &&
|
|
tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) {
|
|
/*
|
|
* At the hard limit, we just die.
|
|
* No need to calculate anything else now.
|
|
*/
|
|
if (print_fatal_signals) {
|
|
pr_info("CPU Watchdog Timeout (hard): %s[%d]\n",
|
|
tsk->comm, task_pid_nr(tsk));
|
|
}
|
|
__group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
|
|
return;
|
|
}
|
|
if (tsk->rt.timeout > DIV_ROUND_UP(soft, USEC_PER_SEC/HZ)) {
|
|
/*
|
|
* At the soft limit, send a SIGXCPU every second.
|
|
*/
|
|
if (soft < hard) {
|
|
soft += USEC_PER_SEC;
|
|
sig->rlim[RLIMIT_RTTIME].rlim_cur = soft;
|
|
}
|
|
if (print_fatal_signals) {
|
|
pr_info("RT Watchdog Timeout (soft): %s[%d]\n",
|
|
tsk->comm, task_pid_nr(tsk));
|
|
}
|
|
__group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
|
|
}
|
|
}
|
|
if (task_cputime_zero(tsk_expires))
|
|
tick_dep_clear_task(tsk, TICK_DEP_BIT_POSIX_TIMER);
|
|
}
|
|
|
|
static inline void stop_process_timers(struct signal_struct *sig)
|
|
{
|
|
struct thread_group_cputimer *cputimer = &sig->cputimer;
|
|
|
|
/* Turn off cputimer->running. This is done without locking. */
|
|
WRITE_ONCE(cputimer->running, 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,
|
|
tsk->signal->leader_pid, cur_time);
|
|
__group_send_sig_info(signo, SEND_SIG_PRIV, tsk);
|
|
}
|
|
|
|
if (it->expires && (!*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;
|
|
u64 utime, ptime, virt_expires, prof_expires;
|
|
u64 sum_sched_runtime, sched_expires;
|
|
struct list_head *timers = sig->cpu_timers;
|
|
struct task_cputime cputime;
|
|
unsigned long soft;
|
|
|
|
/*
|
|
* If cputimer is not running, then there are no active
|
|
* process wide timers (POSIX 1.b, itimers, RLIMIT_CPU).
|
|
*/
|
|
if (!READ_ONCE(tsk->signal->cputimer.running))
|
|
return;
|
|
|
|
/*
|
|
* Signify that a thread is checking for process timers.
|
|
* Write access to this field is protected by the sighand lock.
|
|
*/
|
|
sig->cputimer.checking_timer = true;
|
|
|
|
/*
|
|
* Collect the current process totals.
|
|
*/
|
|
thread_group_cputimer(tsk, &cputime);
|
|
utime = cputime.utime;
|
|
ptime = utime + cputime.stime;
|
|
sum_sched_runtime = cputime.sum_exec_runtime;
|
|
|
|
prof_expires = check_timers_list(timers, firing, ptime);
|
|
virt_expires = check_timers_list(++timers, firing, utime);
|
|
sched_expires = check_timers_list(++timers, firing, sum_sched_runtime);
|
|
|
|
/*
|
|
* Check for the special case process timers.
|
|
*/
|
|
check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime,
|
|
SIGPROF);
|
|
check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
|
|
SIGVTALRM);
|
|
soft = READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
|
|
if (soft != RLIM_INFINITY) {
|
|
unsigned long psecs = div_u64(ptime, NSEC_PER_SEC);
|
|
unsigned long hard =
|
|
READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_max);
|
|
u64 x;
|
|
if (psecs >= hard) {
|
|
/*
|
|
* At the hard limit, we just die.
|
|
* No need to calculate anything else now.
|
|
*/
|
|
if (print_fatal_signals) {
|
|
pr_info("RT Watchdog Timeout (hard): %s[%d]\n",
|
|
tsk->comm, task_pid_nr(tsk));
|
|
}
|
|
__group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);
|
|
return;
|
|
}
|
|
if (psecs >= soft) {
|
|
/*
|
|
* At the soft limit, send a SIGXCPU every second.
|
|
*/
|
|
if (print_fatal_signals) {
|
|
pr_info("CPU Watchdog Timeout (soft): %s[%d]\n",
|
|
tsk->comm, task_pid_nr(tsk));
|
|
}
|
|
__group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk);
|
|
if (soft < hard) {
|
|
soft++;
|
|
sig->rlim[RLIMIT_CPU].rlim_cur = soft;
|
|
}
|
|
}
|
|
x = soft * NSEC_PER_SEC;
|
|
if (!prof_expires || x < prof_expires)
|
|
prof_expires = x;
|
|
}
|
|
|
|
sig->cputime_expires.prof_exp = prof_expires;
|
|
sig->cputime_expires.virt_exp = virt_expires;
|
|
sig->cputime_expires.sched_exp = sched_expires;
|
|
if (task_cputime_zero(&sig->cputime_expires))
|
|
stop_process_timers(sig);
|
|
|
|
sig->cputimer.checking_timer = false;
|
|
}
|
|
|
|
/*
|
|
* This is called from the signal code (via do_schedule_next_timer)
|
|
* when the last timer signal was delivered and we have to reload the timer.
|
|
*/
|
|
void posix_cpu_timer_schedule(struct k_itimer *timer)
|
|
{
|
|
struct sighand_struct *sighand;
|
|
unsigned long flags;
|
|
struct task_struct *p = timer->it.cpu.task;
|
|
u64 now;
|
|
|
|
WARN_ON_ONCE(p == NULL);
|
|
|
|
/*
|
|
* Fetch the current sample and update the timer's expiry time.
|
|
*/
|
|
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
|
|
cpu_clock_sample(timer->it_clock, p, &now);
|
|
bump_cpu_timer(timer, now);
|
|
if (unlikely(p->exit_state))
|
|
goto out;
|
|
|
|
/* Protect timer list r/w in arm_timer() */
|
|
sighand = lock_task_sighand(p, &flags);
|
|
if (!sighand)
|
|
goto out;
|
|
} else {
|
|
/*
|
|
* Protect arm_timer() and timer sampling in case of call to
|
|
* thread_group_cputime().
|
|
*/
|
|
sighand = lock_task_sighand(p, &flags);
|
|
if (unlikely(sighand == NULL)) {
|
|
/*
|
|
* The process has been reaped.
|
|
* We can't even collect a sample any more.
|
|
*/
|
|
timer->it.cpu.expires = 0;
|
|
goto out;
|
|
} else if (unlikely(p->exit_state) && thread_group_empty(p)) {
|
|
unlock_task_sighand(p, &flags);
|
|
/* Optimizations: if the process is dying, no need to rearm */
|
|
goto out;
|
|
}
|
|
cpu_timer_sample_group(timer->it_clock, p, &now);
|
|
bump_cpu_timer(timer, now);
|
|
/* Leave the sighand locked for the call below. */
|
|
}
|
|
|
|
/*
|
|
* Now re-arm for the new expiry time.
|
|
*/
|
|
WARN_ON_ONCE(!irqs_disabled());
|
|
arm_timer(timer);
|
|
unlock_task_sighand(p, &flags);
|
|
|
|
out:
|
|
timer->it_overrun_last = timer->it_overrun;
|
|
timer->it_overrun = -1;
|
|
++timer->it_requeue_pending;
|
|
}
|
|
|
|
/**
|
|
* task_cputime_expired - Compare two task_cputime entities.
|
|
*
|
|
* @sample: The task_cputime structure to be checked for expiration.
|
|
* @expires: Expiration times, against which @sample will be checked.
|
|
*
|
|
* Checks @sample against @expires to see if any field of @sample has expired.
|
|
* Returns true if any field of the former is greater than the corresponding
|
|
* field of the latter if the latter field is set. Otherwise returns false.
|
|
*/
|
|
static inline int task_cputime_expired(const struct task_cputime *sample,
|
|
const struct task_cputime *expires)
|
|
{
|
|
if (expires->utime && sample->utime >= expires->utime)
|
|
return 1;
|
|
if (expires->stime && sample->utime + sample->stime >= expires->stime)
|
|
return 1;
|
|
if (expires->sum_exec_runtime != 0 &&
|
|
sample->sum_exec_runtime >= expires->sum_exec_runtime)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* 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 int fastpath_timer_check(struct task_struct *tsk)
|
|
{
|
|
struct signal_struct *sig;
|
|
|
|
if (!task_cputime_zero(&tsk->cputime_expires)) {
|
|
struct task_cputime task_sample;
|
|
|
|
task_cputime(tsk, &task_sample.utime, &task_sample.stime);
|
|
task_sample.sum_exec_runtime = tsk->se.sum_exec_runtime;
|
|
if (task_cputime_expired(&task_sample, &tsk->cputime_expires))
|
|
return 1;
|
|
}
|
|
|
|
sig = tsk->signal;
|
|
/*
|
|
* Check if thread group timers expired when the cputimer is
|
|
* running and no other thread in the group is already checking
|
|
* 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 check/handle timers.
|
|
*
|
|
* In the worst case scenario, if 'running' or 'checking_timer' gets
|
|
* set but the current thread doesn't see the change yet, we'll wait
|
|
* 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(sig->cputimer.running) &&
|
|
!READ_ONCE(sig->cputimer.checking_timer)) {
|
|
struct task_cputime group_sample;
|
|
|
|
sample_cputime_atomic(&group_sample, &sig->cputimer.cputime_atomic);
|
|
|
|
if (task_cputime_expired(&group_sample, &sig->cputime_expires))
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* 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(struct task_struct *tsk)
|
|
{
|
|
LIST_HEAD(firing);
|
|
struct k_itimer *timer, *next;
|
|
unsigned long flags;
|
|
|
|
WARN_ON_ONCE(!irqs_disabled());
|
|
|
|
/*
|
|
* 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;
|
|
|
|
if (!lock_task_sighand(tsk, &flags))
|
|
return;
|
|
/*
|
|
* 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);
|
|
|
|
/*
|
|
* We must release these locks 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.entry) {
|
|
int cpu_firing;
|
|
|
|
spin_lock(&timer->it_lock);
|
|
list_del_init(&timer->it.cpu.entry);
|
|
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);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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 clock_idx,
|
|
u64 *newval, u64 *oldval)
|
|
{
|
|
u64 now;
|
|
|
|
WARN_ON_ONCE(clock_idx == CPUCLOCK_SCHED);
|
|
cpu_timer_sample_group(clock_idx, tsk, &now);
|
|
|
|
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 we are the earliest timer, or eventually
|
|
* RLIMIT_CPU limit is earlier than prof_exp cpu timer expire.
|
|
*/
|
|
switch (clock_idx) {
|
|
case CPUCLOCK_PROF:
|
|
if (expires_gt(tsk->signal->cputime_expires.prof_exp, *newval))
|
|
tsk->signal->cputime_expires.prof_exp = *newval;
|
|
break;
|
|
case CPUCLOCK_VIRT:
|
|
if (expires_gt(tsk->signal->cputime_expires.virt_exp, *newval))
|
|
tsk->signal->cputime_expires.virt_exp = *newval;
|
|
break;
|
|
}
|
|
|
|
tick_dep_set_signal(tsk->signal, TICK_DEP_BIT_POSIX_TIMER);
|
|
}
|
|
|
|
static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
|
|
struct timespec64 *rqtp, struct itimerspec64 *it)
|
|
{
|
|
struct k_itimer timer;
|
|
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;
|
|
|
|
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 (timer.it.cpu.expires == 0) {
|
|
/*
|
|
* 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.
|
|
*/
|
|
*rqtp = ns_to_timespec64(timer.it.cpu.expires);
|
|
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;
|
|
}
|
|
|
|
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,
|
|
struct timespec64 *rqtp, struct timespec __user *rmtp)
|
|
{
|
|
struct restart_block *restart_block = ¤t->restart_block;
|
|
struct itimerspec64 it;
|
|
struct timespec ts;
|
|
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, &it);
|
|
|
|
if (error == -ERESTART_RESTARTBLOCK) {
|
|
|
|
if (flags & TIMER_ABSTIME)
|
|
return -ERESTARTNOHAND;
|
|
/*
|
|
* Report back to the user the time still remaining.
|
|
*/
|
|
ts = timespec64_to_timespec(it.it_value);
|
|
if (rmtp && copy_to_user(rmtp, &ts, sizeof(*rmtp)))
|
|
return -EFAULT;
|
|
|
|
restart_block->fn = posix_cpu_nsleep_restart;
|
|
restart_block->nanosleep.clockid = which_clock;
|
|
restart_block->nanosleep.rmtp = rmtp;
|
|
restart_block->nanosleep.expires = timespec64_to_ns(rqtp);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
static long posix_cpu_nsleep_restart(struct restart_block *restart_block)
|
|
{
|
|
clockid_t which_clock = restart_block->nanosleep.clockid;
|
|
struct itimerspec64 it;
|
|
struct timespec64 t;
|
|
struct timespec tmp;
|
|
int error;
|
|
|
|
t = ns_to_timespec64(restart_block->nanosleep.expires);
|
|
|
|
error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it);
|
|
|
|
if (error == -ERESTART_RESTARTBLOCK) {
|
|
struct timespec __user *rmtp = restart_block->nanosleep.rmtp;
|
|
/*
|
|
* Report back to the user the time still remaining.
|
|
*/
|
|
tmp = timespec64_to_timespec(it.it_value);
|
|
if (rmtp && copy_to_user(rmtp, &tmp, sizeof(*rmtp)))
|
|
return -EFAULT;
|
|
|
|
restart_block->nanosleep.expires = timespec64_to_ns(&t);
|
|
}
|
|
return error;
|
|
|
|
}
|
|
|
|
#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,
|
|
struct timespec64 *rqtp,
|
|
struct timespec __user *rmtp)
|
|
{
|
|
return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp, rmtp);
|
|
}
|
|
static long process_cpu_nsleep_restart(struct restart_block *restart_block)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
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);
|
|
}
|
|
|
|
struct k_clock clock_posix_cpu = {
|
|
.clock_getres = posix_cpu_clock_getres,
|
|
.clock_set = posix_cpu_clock_set,
|
|
.clock_get = posix_cpu_clock_get,
|
|
.timer_create = posix_cpu_timer_create,
|
|
.nsleep = posix_cpu_nsleep,
|
|
.nsleep_restart = posix_cpu_nsleep_restart,
|
|
.timer_set = posix_cpu_timer_set,
|
|
.timer_del = posix_cpu_timer_del,
|
|
.timer_get = posix_cpu_timer_get,
|
|
};
|
|
|
|
static __init int init_posix_cpu_timers(void)
|
|
{
|
|
struct k_clock process = {
|
|
.clock_getres = process_cpu_clock_getres,
|
|
.clock_get = process_cpu_clock_get,
|
|
.timer_create = process_cpu_timer_create,
|
|
.nsleep = process_cpu_nsleep,
|
|
.nsleep_restart = process_cpu_nsleep_restart,
|
|
};
|
|
struct k_clock thread = {
|
|
.clock_getres = thread_cpu_clock_getres,
|
|
.clock_get = thread_cpu_clock_get,
|
|
.timer_create = thread_cpu_timer_create,
|
|
};
|
|
|
|
posix_timers_register_clock(CLOCK_PROCESS_CPUTIME_ID, &process);
|
|
posix_timers_register_clock(CLOCK_THREAD_CPUTIME_ID, &thread);
|
|
|
|
return 0;
|
|
}
|
|
__initcall(init_posix_cpu_timers);
|