static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *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;
}
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 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_???");
}