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Diffstat (limited to 'kernel/time/posix-cpu-timers.c')
-rw-r--r--kernel/time/posix-cpu-timers.c147
1 files changed, 62 insertions, 85 deletions
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index d2a1e6dd0291..60cb24ac9ebc 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -12,6 +12,11 @@
#include <trace/events/timer.h>
#include <linux/tick.h>
#include <linux/workqueue.h>
+#include <linux/compat.h>
+
+#include "posix-timers.h"
+
+static void posix_cpu_timer_rearm(struct k_itimer *timer);
/*
* Called after updating RLIMIT_CPU to run cpu timer and update
@@ -322,6 +327,8 @@ static int posix_cpu_timer_create(struct k_itimer *new_timer)
if (CPUCLOCK_WHICH(new_timer->it_clock) >= CPUCLOCK_MAX)
return -EINVAL;
+ new_timer->kclock = &clock_posix_cpu;
+
INIT_LIST_HEAD(&new_timer->it.cpu.entry);
rcu_read_lock();
@@ -524,7 +531,8 @@ static void cpu_timer_fire(struct k_itimer *timer)
* reload the timer. But we need to keep it
* ticking in case the signal is deliverable next time.
*/
- posix_cpu_timer_schedule(timer);
+ posix_cpu_timer_rearm(timer);
+ ++timer->it_requeue_pending;
}
}
@@ -572,7 +580,11 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
WARN_ON_ONCE(p == NULL);
- new_expires = timespec64_to_ns(&new->it_value);
+ /*
+ * 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
@@ -712,10 +724,8 @@ static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec64 *itp
*/
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;
+ if (!timer->it.cpu.expires)
return;
- }
/*
* Sample the clock to take the difference with the expiry time.
@@ -739,7 +749,6 @@ static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec64 *itp
* 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);
@@ -976,10 +985,10 @@ static void check_process_timers(struct task_struct *tsk,
}
/*
- * This is called from the signal code (via do_schedule_next_timer)
+ * This is called from the signal code (via posixtimer_rearm)
* when the last timer signal was delivered and we have to reload the timer.
*/
-void posix_cpu_timer_schedule(struct k_itimer *timer)
+static void posix_cpu_timer_rearm(struct k_itimer *timer)
{
struct sighand_struct *sighand;
unsigned long flags;
@@ -995,12 +1004,12 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
cpu_clock_sample(timer->it_clock, p, &now);
bump_cpu_timer(timer, now);
if (unlikely(p->exit_state))
- goto out;
+ return;
/* Protect timer list r/w in arm_timer() */
sighand = lock_task_sighand(p, &flags);
if (!sighand)
- goto out;
+ return;
} else {
/*
* Protect arm_timer() and timer sampling in case of call to
@@ -1013,11 +1022,10 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
* We can't even collect a sample any more.
*/
timer->it.cpu.expires = 0;
- goto out;
+ return;
} 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;
+ /* If the process is dying, no need to rearm */
+ goto unlock;
}
cpu_timer_sample_group(timer->it_clock, p, &now);
bump_cpu_timer(timer, now);
@@ -1029,12 +1037,8 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
*/
WARN_ON_ONCE(!irqs_disabled());
arm_timer(timer);
+unlock:
unlock_task_sighand(p, &flags);
-
-out:
- timer->it_overrun_last = timer->it_overrun;
- timer->it_overrun = -1;
- ++timer->it_requeue_pending;
}
/**
@@ -1227,9 +1231,11 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
}
static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
- struct timespec64 *rqtp, struct itimerspec64 *it)
+ const struct timespec64 *rqtp)
{
+ struct itimerspec64 it;
struct k_itimer timer;
+ u64 expires;
int error;
/*
@@ -1243,12 +1249,13 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
timer.it_process = current;
if (!error) {
static struct itimerspec64 zero_it;
+ struct restart_block *restart;
- memset(it, 0, sizeof *it);
- it->it_value = *rqtp;
+ memset(&it, 0, sizeof(it));
+ it.it_value = *rqtp;
spin_lock_irq(&timer.it_lock);
- error = posix_cpu_timer_set(&timer, flags, it, NULL);
+ error = posix_cpu_timer_set(&timer, flags, &it, NULL);
if (error) {
spin_unlock_irq(&timer.it_lock);
return error;
@@ -1277,8 +1284,8 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
/*
* We were interrupted by a signal.
*/
- *rqtp = ns_to_timespec64(timer.it.cpu.expires);
- error = posix_cpu_timer_set(&timer, 0, &zero_it, it);
+ expires = timer.it.cpu.expires;
+ error = posix_cpu_timer_set(&timer, 0, &zero_it, &it);
if (!error) {
/*
* Timer is now unarmed, deletion can not fail.
@@ -1298,7 +1305,7 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
spin_unlock_irq(&timer.it_lock);
}
- if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) {
+ if ((it.it_value.tv_sec | it.it_value.tv_nsec) == 0) {
/*
* It actually did fire already.
*/
@@ -1306,6 +1313,17 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
}
error = -ERESTART_RESTARTBLOCK;
+ /*
+ * Report back to the user the time still remaining.
+ */
+ restart = &current->restart_block;
+ restart->nanosleep.expires = expires;
+ if (restart->nanosleep.type != TT_NONE) {
+ struct timespec ts;
+
+ ts = timespec64_to_timespec(it.it_value);
+ error = nanosleep_copyout(restart, &ts);
+ }
}
return error;
@@ -1314,11 +1332,9 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
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)
+ const struct timespec64 *rqtp)
{
struct restart_block *restart_block = &current->restart_block;
- struct itimerspec64 it;
- struct timespec ts;
int error;
/*
@@ -1329,23 +1345,15 @@ static int posix_cpu_nsleep(const clockid_t which_clock, int flags,
CPUCLOCK_PID(which_clock) == task_pid_vnr(current)))
return -EINVAL;
- error = do_cpu_nanosleep(which_clock, flags, rqtp, &it);
+ error = do_cpu_nanosleep(which_clock, flags, rqtp);
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;
}
@@ -1353,28 +1361,11 @@ static int posix_cpu_nsleep(const clockid_t which_clock, int flags,
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;
-
+ return do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t);
}
#define PROCESS_CLOCK MAKE_PROCESS_CPUCLOCK(0, CPUCLOCK_SCHED)
@@ -1396,14 +1387,9 @@ static int process_cpu_timer_create(struct k_itimer *timer)
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)
+ const struct timespec64 *rqtp)
{
- return -EINVAL;
+ return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp);
}
static int thread_cpu_clock_getres(const clockid_t which_clock,
struct timespec64 *tp)
@@ -1421,36 +1407,27 @@ static int thread_cpu_timer_create(struct k_itimer *timer)
return posix_cpu_timer_create(timer);
}
-struct k_clock clock_posix_cpu = {
+const 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,
+ .timer_rearm = posix_cpu_timer_rearm,
};
-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);
+const struct k_clock clock_process = {
+ .clock_getres = process_cpu_clock_getres,
+ .clock_get = process_cpu_clock_get,
+ .timer_create = process_cpu_timer_create,
+ .nsleep = process_cpu_nsleep,
+};
- return 0;
-}
-__initcall(init_posix_cpu_timers);
+const struct k_clock clock_thread = {
+ .clock_getres = thread_cpu_clock_getres,
+ .clock_get = thread_cpu_clock_get,
+ .timer_create = thread_cpu_timer_create,
+};