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-rw-r--r--kernel/time/Makefile10
-rw-r--r--kernel/time/alarmtimer.c59
-rw-r--r--kernel/time/hrtimer.c20
-rw-r--r--kernel/time/itimer.c15
-rw-r--r--kernel/time/posix-cpu-timers.c4
-rw-r--r--kernel/time/posix-stubs.c123
-rw-r--r--kernel/time/timekeeping.c90
-rw-r--r--kernel/time/timer.c48
8 files changed, 275 insertions, 94 deletions
diff --git a/kernel/time/Makefile b/kernel/time/Makefile
index 49eca0beed32..976840d29a71 100644
--- a/kernel/time/Makefile
+++ b/kernel/time/Makefile
@@ -1,6 +1,12 @@
-obj-y += time.o timer.o hrtimer.o itimer.o posix-timers.o posix-cpu-timers.o
+obj-y += time.o timer.o hrtimer.o
obj-y += timekeeping.o ntp.o clocksource.o jiffies.o timer_list.o
-obj-y += timeconv.o timecounter.o posix-clock.o alarmtimer.o
+obj-y += timeconv.o timecounter.o alarmtimer.o
+
+ifeq ($(CONFIG_POSIX_TIMERS),y)
+ obj-y += posix-timers.o posix-cpu-timers.o posix-clock.o itimer.o
+else
+ obj-y += posix-stubs.o
+endif
obj-$(CONFIG_GENERIC_CLOCKEVENTS) += clockevents.o tick-common.o
ifeq ($(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST),y)
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 12dd190634ab..9b08ca391aed 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -26,6 +26,9 @@
#include <linux/workqueue.h>
#include <linux/freezer.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/alarmtimer.h>
+
/**
* struct alarm_base - Alarm timer bases
* @lock: Lock for syncrhonized access to the base
@@ -40,7 +43,9 @@ static struct alarm_base {
clockid_t base_clockid;
} alarm_bases[ALARM_NUMTYPE];
-/* freezer delta & lock used to handle clock_nanosleep triggered wakeups */
+/* freezer information to handle clock_nanosleep triggered wakeups */
+static enum alarmtimer_type freezer_alarmtype;
+static ktime_t freezer_expires;
static ktime_t freezer_delta;
static DEFINE_SPINLOCK(freezer_delta_lock);
@@ -194,6 +199,7 @@ static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer)
}
spin_unlock_irqrestore(&base->lock, flags);
+ trace_alarmtimer_fired(alarm, base->gettime());
return ret;
}
@@ -218,15 +224,16 @@ EXPORT_SYMBOL_GPL(alarm_expires_remaining);
*/
static int alarmtimer_suspend(struct device *dev)
{
- struct rtc_time tm;
- ktime_t min, now;
- unsigned long flags;
+ ktime_t min, now, expires;
+ int i, ret, type;
struct rtc_device *rtc;
- int i;
- int ret;
+ unsigned long flags;
+ struct rtc_time tm;
spin_lock_irqsave(&freezer_delta_lock, flags);
min = freezer_delta;
+ expires = freezer_expires;
+ type = freezer_alarmtype;
freezer_delta = ktime_set(0, 0);
spin_unlock_irqrestore(&freezer_delta_lock, flags);
@@ -247,8 +254,11 @@ static int alarmtimer_suspend(struct device *dev)
if (!next)
continue;
delta = ktime_sub(next->expires, base->gettime());
- if (!min.tv64 || (delta.tv64 < min.tv64))
+ if (!min.tv64 || (delta.tv64 < min.tv64)) {
+ expires = next->expires;
min = delta;
+ type = i;
+ }
}
if (min.tv64 == 0)
return 0;
@@ -258,6 +268,8 @@ static int alarmtimer_suspend(struct device *dev)
return -EBUSY;
}
+ trace_alarmtimer_suspend(expires, type);
+
/* Setup an rtc timer to fire that far in the future */
rtc_timer_cancel(rtc, &rtctimer);
rtc_read_time(rtc, &tm);
@@ -295,15 +307,32 @@ static int alarmtimer_resume(struct device *dev)
static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
{
- ktime_t delta;
+ struct alarm_base *base;
unsigned long flags;
- struct alarm_base *base = &alarm_bases[type];
+ ktime_t delta;
+
+ switch(type) {
+ case ALARM_REALTIME:
+ base = &alarm_bases[ALARM_REALTIME];
+ type = ALARM_REALTIME_FREEZER;
+ break;
+ case ALARM_BOOTTIME:
+ base = &alarm_bases[ALARM_BOOTTIME];
+ type = ALARM_BOOTTIME_FREEZER;
+ break;
+ default:
+ WARN_ONCE(1, "Invalid alarm type: %d\n", type);
+ return;
+ }
delta = ktime_sub(absexp, base->gettime());
spin_lock_irqsave(&freezer_delta_lock, flags);
- if (!freezer_delta.tv64 || (delta.tv64 < freezer_delta.tv64))
+ if (!freezer_delta.tv64 || (delta.tv64 < freezer_delta.tv64)) {
freezer_delta = delta;
+ freezer_expires = absexp;
+ freezer_alarmtype = type;
+ }
spin_unlock_irqrestore(&freezer_delta_lock, flags);
}
@@ -342,6 +371,8 @@ void alarm_start(struct alarm *alarm, ktime_t start)
alarmtimer_enqueue(base, alarm);
hrtimer_start(&alarm->timer, alarm->node.expires, HRTIMER_MODE_ABS);
spin_unlock_irqrestore(&base->lock, flags);
+
+ trace_alarmtimer_start(alarm, base->gettime());
}
EXPORT_SYMBOL_GPL(alarm_start);
@@ -390,6 +421,8 @@ int alarm_try_to_cancel(struct alarm *alarm)
if (ret >= 0)
alarmtimer_dequeue(base, alarm);
spin_unlock_irqrestore(&base->lock, flags);
+
+ trace_alarmtimer_cancel(alarm, base->gettime());
return ret;
}
EXPORT_SYMBOL_GPL(alarm_try_to_cancel);
@@ -846,8 +879,10 @@ static int __init alarmtimer_init(void)
alarmtimer_rtc_timer_init();
- posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock);
- posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock);
+ if (IS_ENABLED(CONFIG_POSIX_TIMERS)) {
+ posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock);
+ posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock);
+ }
/* Initialize alarm bases */
alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME;
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index bb5ec425dfe0..08be5c99d26b 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -1742,15 +1742,19 @@ schedule_hrtimeout_range_clock(ktime_t *expires, u64 delta,
* You can set the task state as follows -
*
* %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
- * pass before the routine returns.
+ * pass before the routine returns unless the current task is explicitly
+ * woken up, (e.g. by wake_up_process()).
*
* %TASK_INTERRUPTIBLE - the routine may return early if a signal is
- * delivered to the current task.
+ * delivered to the current task or the current task is explicitly woken
+ * up.
*
* The current task state is guaranteed to be TASK_RUNNING when this
* routine returns.
*
- * Returns 0 when the timer has expired otherwise -EINTR
+ * Returns 0 when the timer has expired. If the task was woken before the
+ * timer expired by a signal (only possible in state TASK_INTERRUPTIBLE) or
+ * by an explicit wakeup, it returns -EINTR.
*/
int __sched schedule_hrtimeout_range(ktime_t *expires, u64 delta,
const enum hrtimer_mode mode)
@@ -1772,15 +1776,19 @@ EXPORT_SYMBOL_GPL(schedule_hrtimeout_range);
* You can set the task state as follows -
*
* %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
- * pass before the routine returns.
+ * pass before the routine returns unless the current task is explicitly
+ * woken up, (e.g. by wake_up_process()).
*
* %TASK_INTERRUPTIBLE - the routine may return early if a signal is
- * delivered to the current task.
+ * delivered to the current task or the current task is explicitly woken
+ * up.
*
* The current task state is guaranteed to be TASK_RUNNING when this
* routine returns.
*
- * Returns 0 when the timer has expired otherwise -EINTR
+ * Returns 0 when the timer has expired. If the task was woken before the
+ * timer expired by a signal (only possible in state TASK_INTERRUPTIBLE) or
+ * by an explicit wakeup, it returns -EINTR.
*/
int __sched schedule_hrtimeout(ktime_t *expires,
const enum hrtimer_mode mode)
diff --git a/kernel/time/itimer.c b/kernel/time/itimer.c
index 1d5c7204ddc9..2b9f45bc955d 100644
--- a/kernel/time/itimer.c
+++ b/kernel/time/itimer.c
@@ -238,6 +238,8 @@ again:
return 0;
}
+#ifdef __ARCH_WANT_SYS_ALARM
+
/**
* alarm_setitimer - set alarm in seconds
*
@@ -250,7 +252,7 @@ again:
* On 32 bit machines the seconds value is limited to (INT_MAX/2) to avoid
* negative timeval settings which would cause immediate expiry.
*/
-unsigned int alarm_setitimer(unsigned int seconds)
+static unsigned int alarm_setitimer(unsigned int seconds)
{
struct itimerval it_new, it_old;
@@ -275,6 +277,17 @@ unsigned int alarm_setitimer(unsigned int seconds)
return it_old.it_value.tv_sec;
}
+/*
+ * For backwards compatibility? This can be done in libc so Alpha
+ * and all newer ports shouldn't need it.
+ */
+SYSCALL_DEFINE1(alarm, unsigned int, seconds)
+{
+ return alarm_setitimer(seconds);
+}
+
+#endif
+
SYSCALL_DEFINE3(setitimer, int, which, struct itimerval __user *, value,
struct itimerval __user *, ovalue)
{
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index e887ffc8eef3..f246763c9947 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -9,7 +9,6 @@
#include <asm/uaccess.h>
#include <linux/kernel_stat.h>
#include <trace/events/timer.h>
-#include <linux/random.h>
#include <linux/tick.h>
#include <linux/workqueue.h>
@@ -447,10 +446,7 @@ static void cleanup_timers(struct list_head *head)
*/
void posix_cpu_timers_exit(struct task_struct *tsk)
{
- add_device_randomness((const void*) &tsk->se.sum_exec_runtime,
- sizeof(unsigned long long));
cleanup_timers(tsk->cpu_timers);
-
}
void posix_cpu_timers_exit_group(struct task_struct *tsk)
{
diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c
new file mode 100644
index 000000000000..cd6716e115e8
--- /dev/null
+++ b/kernel/time/posix-stubs.c
@@ -0,0 +1,123 @@
+/*
+ * Dummy stubs used when CONFIG_POSIX_TIMERS=n
+ *
+ * Created by: Nicolas Pitre, July 2016
+ * Copyright: (C) 2016 Linaro Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/syscalls.h>
+#include <linux/ktime.h>
+#include <linux/timekeeping.h>
+#include <linux/posix-timers.h>
+
+asmlinkage long sys_ni_posix_timers(void)
+{
+ pr_err_once("process %d (%s) attempted a POSIX timer syscall "
+ "while CONFIG_POSIX_TIMERS is not set\n",
+ current->pid, current->comm);
+ return -ENOSYS;
+}
+
+#define SYS_NI(name) SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers)
+
+SYS_NI(timer_create);
+SYS_NI(timer_gettime);
+SYS_NI(timer_getoverrun);
+SYS_NI(timer_settime);
+SYS_NI(timer_delete);
+SYS_NI(clock_adjtime);
+SYS_NI(getitimer);
+SYS_NI(setitimer);
+#ifdef __ARCH_WANT_SYS_ALARM
+SYS_NI(alarm);
+#endif
+
+/*
+ * We preserve minimal support for CLOCK_REALTIME and CLOCK_MONOTONIC
+ * as it is easy to remain compatible with little code. CLOCK_BOOTTIME
+ * is also included for convenience as at least systemd uses it.
+ */
+
+SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
+ const struct timespec __user *, tp)
+{
+ struct timespec new_tp;
+
+ if (which_clock != CLOCK_REALTIME)
+ return -EINVAL;
+ if (copy_from_user(&new_tp, tp, sizeof (*tp)))
+ return -EFAULT;
+ return do_sys_settimeofday(&new_tp, NULL);
+}
+
+SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
+ struct timespec __user *,tp)
+{
+ struct timespec kernel_tp;
+
+ switch (which_clock) {
+ case CLOCK_REALTIME: ktime_get_real_ts(&kernel_tp); break;
+ case CLOCK_MONOTONIC: ktime_get_ts(&kernel_tp); break;
+ case CLOCK_BOOTTIME: get_monotonic_boottime(&kernel_tp); break;
+ default: return -EINVAL;
+ }
+ if (copy_to_user(tp, &kernel_tp, sizeof (kernel_tp)))
+ return -EFAULT;
+ return 0;
+}
+
+SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock, struct timespec __user *, tp)
+{
+ struct timespec rtn_tp = {
+ .tv_sec = 0,
+ .tv_nsec = hrtimer_resolution,
+ };
+
+ switch (which_clock) {
+ case CLOCK_REALTIME:
+ case CLOCK_MONOTONIC:
+ case CLOCK_BOOTTIME:
+ if (copy_to_user(tp, &rtn_tp, sizeof(rtn_tp)))
+ return -EFAULT;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
+ const struct timespec __user *, rqtp,
+ struct timespec __user *, rmtp)
+{
+ struct timespec t;
+
+ switch (which_clock) {
+ case CLOCK_REALTIME:
+ case CLOCK_MONOTONIC:
+ case CLOCK_BOOTTIME:
+ if (copy_from_user(&t, rqtp, sizeof (struct timespec)))
+ return -EFAULT;
+ if (!timespec_valid(&t))
+ return -EINVAL;
+ return hrtimer_nanosleep(&t, rmtp, flags & TIMER_ABSTIME ?
+ HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
+ which_clock);
+ default:
+ return -EINVAL;
+ }
+}
+
+#ifdef CONFIG_COMPAT
+long clock_nanosleep_restart(struct restart_block *restart_block)
+{
+ return hrtimer_nanosleep_restart(restart_block);
+}
+#endif
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 37dec7e3db43..da233cdf89b0 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -258,10 +258,9 @@ static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)
tk->cycle_interval = interval;
/* Go back from cycles -> shifted ns */
- tk->xtime_interval = (u64) interval * clock->mult;
+ tk->xtime_interval = interval * clock->mult;
tk->xtime_remainder = ntpinterval - tk->xtime_interval;
- tk->raw_interval =
- ((u64) interval * clock->mult) >> clock->shift;
+ tk->raw_interval = (interval * clock->mult) >> clock->shift;
/* if changing clocks, convert xtime_nsec shift units */
if (old_clock) {
@@ -299,10 +298,10 @@ u32 (*arch_gettimeoffset)(void) = default_arch_gettimeoffset;
static inline u32 arch_gettimeoffset(void) { return 0; }
#endif
-static inline s64 timekeeping_delta_to_ns(struct tk_read_base *tkr,
+static inline u64 timekeeping_delta_to_ns(struct tk_read_base *tkr,
cycle_t delta)
{
- s64 nsec;
+ u64 nsec;
nsec = delta * tkr->mult + tkr->xtime_nsec;
nsec >>= tkr->shift;
@@ -311,7 +310,7 @@ static inline s64 timekeeping_delta_to_ns(struct tk_read_base *tkr,
return nsec + arch_gettimeoffset();
}
-static inline s64 timekeeping_get_ns(struct tk_read_base *tkr)
+static inline u64 timekeeping_get_ns(struct tk_read_base *tkr)
{
cycle_t delta;
@@ -319,8 +318,8 @@ static inline s64 timekeeping_get_ns(struct tk_read_base *tkr)
return timekeeping_delta_to_ns(tkr, delta);
}
-static inline s64 timekeeping_cycles_to_ns(struct tk_read_base *tkr,
- cycle_t cycles)
+static inline u64 timekeeping_cycles_to_ns(struct tk_read_base *tkr,
+ cycle_t cycles)
{
cycle_t delta;
@@ -425,6 +424,35 @@ u64 ktime_get_raw_fast_ns(void)
}
EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns);
+/**
+ * ktime_get_boot_fast_ns - NMI safe and fast access to boot clock.
+ *
+ * To keep it NMI safe since we're accessing from tracing, we're not using a
+ * separate timekeeper with updates to monotonic clock and boot offset
+ * protected with seqlocks. This has the following minor side effects:
+ *
+ * (1) Its possible that a timestamp be taken after the boot offset is updated
+ * but before the timekeeper is updated. If this happens, the new boot offset
+ * is added to the old timekeeping making the clock appear to update slightly
+ * earlier:
+ * CPU 0 CPU 1
+ * timekeeping_inject_sleeptime64()
+ * __timekeeping_inject_sleeptime(tk, delta);
+ * timestamp();
+ * timekeeping_update(tk, TK_CLEAR_NTP...);
+ *
+ * (2) On 32-bit systems, the 64-bit boot offset (tk->offs_boot) may be
+ * partially updated. Since the tk->offs_boot update is a rare event, this
+ * should be a rare occurrence which postprocessing should be able to handle.
+ */
+u64 notrace ktime_get_boot_fast_ns(void)
+{
+ struct timekeeper *tk = &tk_core.timekeeper;
+
+ return (ktime_get_mono_fast_ns() + ktime_to_ns(tk->offs_boot));
+}
+EXPORT_SYMBOL_GPL(ktime_get_boot_fast_ns);
+
/* Suspend-time cycles value for halted fast timekeeper. */
static cycle_t cycles_at_suspend;
@@ -623,7 +651,7 @@ static void timekeeping_forward_now(struct timekeeper *tk)
{
struct clocksource *clock = tk->tkr_mono.clock;
cycle_t cycle_now, delta;
- s64 nsec;
+ u64 nsec;
cycle_now = tk->tkr_mono.read(clock);
delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask);
@@ -652,7 +680,7 @@ int __getnstimeofday64(struct timespec64 *ts)
{
struct timekeeper *tk = &tk_core.timekeeper;
unsigned long seq;
- s64 nsecs = 0;
+ u64 nsecs;
do {
seq = read_seqcount_begin(&tk_core.seq);
@@ -692,7 +720,7 @@ ktime_t ktime_get(void)
struct timekeeper *tk = &tk_core.timekeeper;
unsigned int seq;
ktime_t base;
- s64 nsecs;
+ u64 nsecs;
WARN_ON(timekeeping_suspended);
@@ -735,7 +763,7 @@ ktime_t ktime_get_with_offset(enum tk_offsets offs)
struct timekeeper *tk = &tk_core.timekeeper;
unsigned int seq;
ktime_t base, *offset = offsets[offs];
- s64 nsecs;
+ u64 nsecs;
WARN_ON(timekeeping_suspended);
@@ -779,7 +807,7 @@ ktime_t ktime_get_raw(void)
struct timekeeper *tk = &tk_core.timekeeper;
unsigned int seq;
ktime_t base;
- s64 nsecs;
+ u64 nsecs;
do {
seq = read_seqcount_begin(&tk_core.seq);
@@ -804,8 +832,8 @@ void ktime_get_ts64(struct timespec64 *ts)
{
struct timekeeper *tk = &tk_core.timekeeper;
struct timespec64 tomono;
- s64 nsec;
unsigned int seq;
+ u64 nsec;
WARN_ON(timekeeping_suspended);
@@ -893,8 +921,8 @@ void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot)
unsigned long seq;
ktime_t base_raw;
ktime_t base_real;
- s64 nsec_raw;
- s64 nsec_real;
+ u64 nsec_raw;
+ u64 nsec_real;
cycle_t now;
WARN_ON_ONCE(timekeeping_suspended);
@@ -1052,7 +1080,7 @@ int get_device_system_crosststamp(int (*get_time_fn)
cycle_t cycles, now, interval_start;
unsigned int clock_was_set_seq = 0;
ktime_t base_real, base_raw;
- s64 nsec_real, nsec_raw;
+ u64 nsec_real, nsec_raw;
u8 cs_was_changed_seq;
unsigned long seq;
bool do_interp;
@@ -1365,7 +1393,7 @@ void getrawmonotonic64(struct timespec64 *ts)
struct timekeeper *tk = &tk_core.timekeeper;
struct timespec64 ts64;
unsigned long seq;
- s64 nsecs;
+ u64 nsecs;
do {
seq = read_seqcount_begin(&tk_core.seq);
@@ -1616,7 +1644,7 @@ void timekeeping_resume(void)
struct clocksource *clock = tk->tkr_mono.clock;
unsigned long flags;
struct timespec64 ts_new, ts_delta;
- cycle_t cycle_now, cycle_delta;
+ cycle_t cycle_now;
sleeptime_injected = false;
read_persistent_clock64(&ts_new);
@@ -1642,27 +1670,11 @@ void timekeeping_resume(void)
cycle_now = tk->tkr_mono.read(clock);
if ((clock->flags & CLOCK_SOURCE_SUSPEND_NONSTOP) &&
cycle_now > tk->tkr_mono.cycle_last) {
- u64 num, max = ULLONG_MAX;
- u32 mult = clock->mult;
- u32 shift = clock->shift;
- s64 nsec = 0;
-
- cycle_delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last,
- tk->tkr_mono.mask);
-
- /*
- * "cycle_delta * mutl" may cause 64 bits overflow, if the
- * suspended time is too long. In that case we need do the
- * 64 bits math carefully
- */
- do_div(max, mult);
- if (cycle_delta > max) {
- num = div64_u64(cycle_delta, max);
- nsec = (((u64) max * mult) >> shift) * num;
- cycle_delta -= num * max;
- }
- nsec += ((u64) cycle_delta * mult) >> shift;
+ u64 nsec, cyc_delta;
+ cyc_delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last,
+ tk->tkr_mono.mask);
+ nsec = mul_u64_u32_shr(cyc_delta, clock->mult, clock->shift);
ts_delta = ns_to_timespec64(nsec);
sleeptime_injected = true;
} else if (timespec64_compare(&ts_new, &timekeeping_suspend_time) > 0) {
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index c611c47de884..ea4fbf8477a9 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -1615,7 +1615,8 @@ void update_process_times(int user_tick)
irq_work_tick();
#endif
scheduler_tick();
- run_posix_cpu_timers(p);
+ if (IS_ENABLED(CONFIG_POSIX_TIMERS))
+ run_posix_cpu_timers(p);
}
/**
@@ -1676,19 +1677,6 @@ void run_local_timers(void)
raise_softirq(TIMER_SOFTIRQ);
}
-#ifdef __ARCH_WANT_SYS_ALARM
-
-/*
- * For backwards compatibility? This can be done in libc so Alpha
- * and all newer ports shouldn't need it.
- */
-SYSCALL_DEFINE1(alarm, unsigned int, seconds)
-{
- return alarm_setitimer(seconds);
-}
-
-#endif
-
static void process_timeout(unsigned long __data)
{
wake_up_process((struct task_struct *)__data);
@@ -1705,11 +1693,12 @@ static void process_timeout(unsigned long __data)
* You can set the task state as follows -
*
* %TASK_UNINTERRUPTIBLE - at least @timeout jiffies are guaranteed to
- * pass before the routine returns. The routine will return 0
+ * pass before the routine returns unless the current task is explicitly
+ * woken up, (e.g. by wake_up_process())".
*
* %TASK_INTERRUPTIBLE - the routine may return early if a signal is
- * delivered to the current task. In this case the remaining time
- * in jiffies will be returned, or 0 if the timer expired in time
+ * delivered to the current task or the current task is explicitly woken
+ * up.
*
* The current task state is guaranteed to be TASK_RUNNING when this
* routine returns.
@@ -1718,7 +1707,9 @@ static void process_timeout(unsigned long __data)
* the CPU away without a bound on the timeout. In this case the return
* value will be %MAX_SCHEDULE_TIMEOUT.
*
- * In all cases the return value is guaranteed to be non-negative.
+ * Returns 0 when the timer has expired otherwise the remaining time in
+ * jiffies will be returned. In all cases the return value is guaranteed
+ * to be non-negative.
*/
signed long __sched schedule_timeout(signed long timeout)
{
@@ -1910,16 +1901,6 @@ unsigned long msleep_interruptible(unsigned int msecs)
EXPORT_SYMBOL(msleep_interruptible);
-static void __sched do_usleep_range(unsigned long min, unsigned long max)
-{
- ktime_t kmin;
- u64 delta;
-
- kmin = ktime_set(0, min * NSEC_PER_USEC);
- delta = (u64)(max - min) * NSEC_PER_USEC;
- schedule_hrtimeout_range(&kmin, delta, HRTIMER_MODE_REL);
-}
-
/**
* usleep_range - Sleep for an approximate time
* @min: Minimum time in usecs to sleep
@@ -1933,7 +1914,14 @@ static void __sched do_usleep_range(unsigned long min, unsigned long max)
*/
void __sched usleep_range(unsigned long min, unsigned long max)
{
- __set_current_state(TASK_UNINTERRUPTIBLE);
- do_usleep_range(min, max);
+ ktime_t exp = ktime_add_us(ktime_get(), min);
+ u64 delta = (u64)(max - min) * NSEC_PER_USEC;
+
+ for (;;) {
+ __set_current_state(TASK_UNINTERRUPTIBLE);
+ /* Do not return before the requested sleep time has elapsed */
+ if (!schedule_hrtimeout_range(&exp, delta, HRTIMER_MODE_ABS))
+ break;
+ }
}
EXPORT_SYMBOL(usleep_range);