/*
* 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) {
unsigned long long 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, expires_to_cputime(exp)))
cputime_expires->prof_exp = expires_to_cputime(exp);
break;
case CPUCLOCK_VIRT:
if (expires_gt(cputime_expires->virt_exp, expires_to_cputime(exp)))
cputime_expires->virt_exp = expires_to_cputime(exp);
break;
case CPUCLOCK_SCHED:
if (cputime_expires->sched_exp == 0 ||
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);
}
}
/* Set CLOCK to value TP. */
int
__clock_settime (clockid_t clock_id, const struct timespec *tp)
{
int retval;
/* Make sure the time cvalue is OK. */
if (tp->tv_nsec < 0 || tp->tv_nsec >= 1000000000)
{
__set_errno (EINVAL);
return -1;
}
switch (clock_id)
{
#define HANDLE_REALTIME \
do { \
struct timeval tv; \
TIMESPEC_TO_TIMEVAL (&tv, tp); \
\
retval = settimeofday (&tv, NULL); \
} while (0)
#ifdef SYSDEP_SETTIME
SYSDEP_SETTIME;
#endif
#ifndef HANDLED_REALTIME
case CLOCK_REALTIME:
HANDLE_REALTIME;
break;
#endif
default:
#ifdef SYSDEP_SETTIME_CPU
SYSDEP_SETTIME_CPU;
#endif
#ifndef HANDLED_CPUTIME
# if HP_TIMING_AVAIL
if (CPUCLOCK_WHICH (clock_id) == CLOCK_PROCESS_CPUTIME_ID
|| CPUCLOCK_WHICH (clock_id) == CLOCK_THREAD_CPUTIME_ID)
retval = hp_timing_settime (clock_id, tp);
else
# endif
{
__set_errno (EINVAL);
retval = -1;
}
#endif
break;
}
return retval;
}
/*
* Update expiry time from increment, and increase overrun count,
* given the current clock sample.
*/
static void bump_cpu_timer(struct k_itimer *timer,
union cpu_time_count now)
{
int i;
if (timer->it.cpu.incr.sched == 0)
return;
if (CPUCLOCK_WHICH(timer->it_clock) == CPUCLOCK_SCHED) {
unsigned long long delta, incr;
if (now.sched < timer->it.cpu.expires.sched)
return;
incr = timer->it.cpu.incr.sched;
delta = now.sched + incr - timer->it.cpu.expires.sched;
/* 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.sched += incr;
timer->it_overrun += 1 << i;
delta -= incr;
}
} else {
static void sample_to_timespec(const clockid_t which_clock,
unsigned long long expires,
struct timespec *tp)
{
if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED)
*tp = ns_to_timespec(expires);
else
cputime_to_timespec((__force cputime_t)expires, tp);
}
static void sample_to_timespec(const clockid_t which_clock,
union cpu_time_count cpu,
struct timespec *tp)
{
if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED)
*tp = ns_to_timespec(cpu.sched);
else
cputime_to_timespec(cpu.cpu, tp);
}
static inline int cpu_time_before(const clockid_t which_clock,
union cpu_time_count now,
union cpu_time_count then)
{
if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
return now.sched < then.sched;
} else {
return cputime_lt(now.cpu, then.cpu);
}
}
static inline void cpu_time_add(const clockid_t which_clock,
union cpu_time_count *acc,
union cpu_time_count val)
{
if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
acc->sched += val.sched;
} else {
acc->cpu = cputime_add(acc->cpu, val.cpu);
}
}
static void sample_to_timespec(const clockid_t which_clock,
union cpu_time_count cpu,
struct timespec *tp)
{
if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
tp->tv_sec = div_long_long_rem(cpu.sched,
NSEC_PER_SEC, &tp->tv_nsec);
} else {
cputime_to_timespec(cpu.cpu, tp);
}
}
static inline union cpu_time_count cpu_time_sub(const clockid_t which_clock,
union cpu_time_count a,
union cpu_time_count b)
{
if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
a.sched -= b.sched;
} else {
a.cpu = cputime_sub(a.cpu, b.cpu);
}
return a;
}
static inline union cpu_time_count
timespec_to_sample(const clockid_t which_clock, const struct timespec *tp)
{
union cpu_time_count ret;
ret.sched = 0; /* high half always zero when .cpu used */
if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) {
ret.sched = (unsigned long long)tp->tv_sec * NSEC_PER_SEC + tp->tv_nsec;
} else {
ret.cpu = timespec_to_cputime(tp);
}
return ret;
}
static int
posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *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;
}
/*
* Sample a per-thread clock for the given task.
*/
static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p,
unsigned long long *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;
}
/*
* 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;
}
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;
read_lock(&tasklist_lock);
p = find_task_by_pid(pid);
if (!p || (CPUCLOCK_PERTHREAD(which_clock) ?
p->tgid != current->tgid : p->tgid != pid)) {
error = -EINVAL;
}
read_unlock(&tasklist_lock);
return error;
}
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;
read_lock(&tasklist_lock);
p = find_task_by_vpid(pid);
if (!p || !(CPUCLOCK_PERTHREAD(which_clock) ?
same_thread_group(p, current) : thread_group_leader(p))) {
error = -EINVAL;
}
read_unlock(&tasklist_lock);
return error;
}
/*
* 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;
}
/*
* 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,
unsigned long long *sample)
{
struct task_cputime cputime;
switch (CPUCLOCK_WHICH(which_clock)) {
default:
return -EINVAL;
case CPUCLOCK_PROF:
thread_group_cputime(p, &cputime);
*sample = cputime_to_expires(cputime.utime + cputime.stime);
break;
case CPUCLOCK_VIRT:
thread_group_cputime(p, &cputime);
*sample = cputime_to_expires(cputime.utime);
break;
case CPUCLOCK_SCHED:
thread_group_cputime(p, &cputime);
*sample = cputime.sum_exec_runtime;
break;
}
return 0;
}