/*
* 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);
}
}
static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
{
const pid_t pid = CPUCLOCK_PID(which_clock);
int error = -EINVAL;
unsigned long long rtn;
if (pid == 0) {
/*
* Special case constant value for our own clocks.
* We don't have to do any lookup to find ourselves.
*/
if (CPUCLOCK_PERTHREAD(which_clock)) {
/*
* Sampling just ourselves we can do with no locking.
*/
error = cpu_clock_sample(which_clock,
current, &rtn);
} else {
read_lock(&tasklist_lock);
error = cpu_clock_sample_group(which_clock,
current, &rtn);
read_unlock(&tasklist_lock);
}
} 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) {
if (CPUCLOCK_PERTHREAD(which_clock)) {
if (same_thread_group(p, current)) {
error = cpu_clock_sample(which_clock,
p, &rtn);
}
} else {
read_lock(&tasklist_lock);
if (thread_group_leader(p) && p->sighand) {
error =
cpu_clock_sample_group(which_clock,
p, &rtn);
}
read_unlock(&tasklist_lock);
}
}
rcu_read_unlock();
}
if (error)
return error;
sample_to_timespec(which_clock, rtn, tp);
return 0;
}
static int posix_cpu_clock_get_task(struct task_struct *tsk,
const clockid_t which_clock,
struct timespec *tp)
{
int err = -EINVAL;
unsigned long long rtn;
if (CPUCLOCK_PERTHREAD(which_clock)) {
if (same_thread_group(tsk, current))
err = cpu_clock_sample(which_clock, tsk, &rtn);
} else {
unsigned long flags;
struct sighand_struct *sighand;
/*
* while_each_thread() is not yet entirely RCU safe,
* keep locking the group while sampling process
* clock for now.
*/
sighand = lock_task_sighand(tsk, &flags);
if (!sighand)
return err;
if (tsk == current || thread_group_leader(tsk))
err = cpu_clock_sample_group(which_clock, tsk, &rtn);
unlock_task_sighand(tsk, &flags);
}
if (!err)
sample_to_timespec(which_clock, rtn, tp);
return err;
}
static int posix_cpu_clock_get_task(struct task_struct *tsk,
const clockid_t which_clock,
struct timespec *tp)
{
int err = -EINVAL;
unsigned long long 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)
sample_to_timespec(which_clock, rtn, tp);
return err;
}
static void
printclockname(int clockid)
{
#ifdef CLOCKID_TO_FD
if (clockid < 0) {
if ((clockid & CLOCKFD_MASK) == CLOCKFD)
tprintf("FD_TO_CLOCKID(%d)", CLOCKID_TO_FD(clockid));
else {
if(CPUCLOCK_PERTHREAD(clockid))
tprintf("MAKE_THREAD_CPUCLOCK(%d,", CPUCLOCK_PID(clockid));
else
tprintf("MAKE_PROCESS_CPUCLOCK(%d,", CPUCLOCK_PID(clockid));
printxval(cpuclocknames, clockid & CLOCKFD_MASK, "CPUCLOCK_???");
tprints(")");
}
}
else
#endif
printxval(clocknames, clockid, "CLOCK_???");
}
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;
}
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 void
printclockname(int clockid)
{
#ifdef CLOCKID_TO_FD
# include "xlat/cpuclocknames.h"
if (clockid < 0) {
if (xlat_verbose(xlat_verbosity) != XLAT_STYLE_ABBREV)
tprintf("%d", clockid);
if (xlat_verbose(xlat_verbosity) == XLAT_STYLE_RAW)
return;
if (xlat_verbose(xlat_verbosity) == XLAT_STYLE_VERBOSE)
tprints(" /* ");
if ((clockid & CLOCKFD_MASK) == CLOCKFD)
tprintf("FD_TO_CLOCKID(%d)", CLOCKID_TO_FD(clockid));
else {
tprintf("%s(%d,",
CPUCLOCK_PERTHREAD(clockid) ?
"MAKE_THREAD_CPUCLOCK" :
"MAKE_PROCESS_CPUCLOCK",
CPUCLOCK_PID(clockid));
printxval_index(cpuclocknames,
(unsigned int) clockid & CLOCKFD_MASK,
"CPUCLOCK_???");
tprints(")");
}
if (xlat_verbose(xlat_verbosity) == XLAT_STYLE_VERBOSE)
tprints(" */");
} else
#endif
printxval_index(clocknames, clockid, "CLOCK_???");
}
