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Groups > linux.kernel > #1519579 > unrolled thread

[PATCH v4 0/6] make POSIX timers optional with some Kconfig help

Started byNicolas Pitre <nicolas.pitre@linaro.org>
First post2016-11-11 06:20 +0100
Last post2016-11-16 09:40 +0100
Articles 4 — 3 participants

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Contents

  [PATCH v4 0/6] make POSIX timers optional with some Kconfig help Nicolas Pitre <nicolas.pitre@linaro.org> - 2016-11-11 06:20 +0100
    [PATCH v4 6/6] posix-timers: make it configurable Nicolas Pitre <nicolas.pitre@linaro.org> - 2016-11-11 06:20 +0100
      Re: [PATCH v4 6/6] posix-timers: make it configurable John Stultz <john.stultz@linaro.org> - 2016-11-16 01:50 +0100
      [tip:timers/core] posix-timers: Make them configurable tip-bot for Nicolas Pitre <tipbot@zytor.com> - 2016-11-16 09:40 +0100

#1519579 — [PATCH v4 0/6] make POSIX timers optional with some Kconfig help

FromNicolas Pitre <nicolas.pitre@linaro.org>
Date2016-11-11 06:20 +0100
Subject[PATCH v4 0/6] make POSIX timers optional with some Kconfig help
Message-ID<sCcpP-8on-3@gated-at.bofh.it>
Many embedded systems don't need the full POSIX timer support.
Configuring them out provides a nice kernel image size reduction.

When POSIX timers are configured out, the PTP clock subsystem should be
left out as well. However a bunch of ethernet drivers currently *select*
the later in their Kconfig entries. Therefore some more work was needed
to break that hard dependency from those drivers without preventing their
usage altogether.

Therefore this series also includes kconfig changes to implement a new
keyword to express some reverse dependencies like "select" does, named
"imply", and still allowing for the target config symbol to be disabled
if the user or a direct dependency says so.

At this point I'd like to gather ACKs especially from people in the "To"
field. Ideally this would need to go upstream as a single series to avoid
cross subsystem dependency issues.  So far it was suggested that this could
go via the kbuild tree. Given the end goal and the included timer cleanup
patches I'd lean towards the timer tree but any tree would suit me just
as well.

This is also available here for those who prefer a git tree:
git://git.linaro.org/people/nicolas.pitre/linux/ configurable_posix_timers

Changes from v3:

- Added a patch to move sys_alarm to itimer.c where the support code lives.
- Added a patch to move entropy collection out of posix-cpu-timers.c.
- Remove itimer as well when POSIX_TIMERS=n as they rely on code already
  removed. This means the getitimer, setitimer and alarm syscalls are also
  stubbed out in that case.
- Reverted the addition of empty timer stubs from posix-timers.h. Since
  there is only a few callers, it's better to conditionalize call sites
  instead, and get a link error if some were missed. Easier to clearly
  ponder the implications that way.
- Collected more ACKs.

Changes from v2:

- Dropped the patch adding the "suggest" keyword as nothing uses it.
  Requested by Paul Bolle.
- Various documentation and commit log clarifications, prompted also
  by Paul Bolle.
- Collected more ACKs.

Changes from v1:

- added "suggest" to kconfig for completeness
- various typo fixes
- small "imply" effect visibility fix

The bulk of the diffstat comes from the kconfig lex parser regeneration.

Diffstat:

 Documentation/kbuild/kconfig-language.txt       |   29 +
 arch/alpha/kernel/osf_sys.c                     |    8 +
 drivers/Makefile                                |    2 +-
 drivers/char/Kconfig                            |    1 +
 drivers/net/ethernet/adi/Kconfig                |    2 +-
 drivers/net/ethernet/amd/Kconfig                |    2 +-
 drivers/net/ethernet/amd/xgbe/xgbe-main.c       |    6 +-
 drivers/net/ethernet/broadcom/Kconfig           |    4 +-
 drivers/net/ethernet/cavium/Kconfig             |    2 +-
 drivers/net/ethernet/freescale/Kconfig          |    2 +-
 drivers/net/ethernet/intel/Kconfig              |   10 +-
 drivers/net/ethernet/mellanox/mlx4/Kconfig      |    2 +-
 drivers/net/ethernet/mellanox/mlx5/core/Kconfig |    2 +-
 drivers/net/ethernet/renesas/Kconfig            |    2 +-
 drivers/net/ethernet/samsung/Kconfig            |    2 +-
 drivers/net/ethernet/sfc/Kconfig                |    2 +-
 drivers/net/ethernet/stmicro/stmmac/Kconfig     |    2 +-
 drivers/net/ethernet/ti/Kconfig                 |    2 +-
 drivers/net/ethernet/tile/Kconfig               |    2 +-
 drivers/ptp/Kconfig                             |   10 +-
 fs/exec.c                                       |    2 +
 include/linux/ptp_clock_kernel.h                |   65 +-
 include/linux/time.h                            |    2 -
 init/Kconfig                                    |   17 +
 kernel/compat.c                                 |    8 +
 kernel/exit.c                                   |   15 +-
 kernel/fork.c                                   |    2 +
 kernel/signal.c                                 |    6 +
 kernel/sys.c                                    |    3 +-
 kernel/time/Makefile                            |   10 +-
 kernel/time/alarmtimer.c                        |    6 +-
 kernel/time/itimer.c                            |   15 +-
 kernel/time/posix-cpu-timers.c                  |    4 -
 kernel/time/posix-stubs.c                       |  123 ++
 kernel/time/timer.c                             |   16 +-
 scripts/kconfig/expr.h                          |    2 +
 scripts/kconfig/menu.c                          |   55 +-
 scripts/kconfig/symbol.c                        |   24 +-
 scripts/kconfig/zconf.gperf                     |    1 +
 scripts/kconfig/zconf.hash.c_shipped            |   30 +-
 scripts/kconfig/zconf.tab.c_shipped             | 1581 +++++++++++------------
 scripts/kconfig/zconf.y                         |   16 +-
 security/selinux/hooks.c                        |   11 +-
 43 files changed, 1148 insertions(+), 960 deletions(-)

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#1519580 — [PATCH v4 6/6] posix-timers: make it configurable

FromNicolas Pitre <nicolas.pitre@linaro.org>
Date2016-11-11 06:20 +0100
Subject[PATCH v4 6/6] posix-timers: make it configurable
Message-ID<sCcpP-8on-25@gated-at.bofh.it>
In reply to#1519579
Some embedded systems have no use for them.  This removes about
25KB from the kernel binary size when configured out.

Corresponding syscalls are routed to a stub logging the attempt to
use those syscalls which should be enough of a clue if they were
disabled without proper consideration. They are: timer_create,
timer_gettime: timer_getoverrun, timer_settime, timer_delete,
clock_adjtime, setitimer, getitimer, alarm.

The clock_settime, clock_gettime, clock_getres and clock_nanosleep
syscalls are replaced by simple wrappers compatible with CLOCK_REALTIME,
CLOCK_MONOTONIC and CLOCK_BOOTTIME only which should cover the vast
majority of use cases with very little code.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/alpha/kernel/osf_sys.c |   8 +++
 drivers/char/Kconfig        |   1 +
 drivers/ptp/Kconfig         |   2 +-
 fs/exec.c                   |   2 +
 init/Kconfig                |  17 ++++++
 kernel/compat.c             |   8 +++
 kernel/exit.c               |  11 +++-
 kernel/fork.c               |   2 +
 kernel/signal.c             |   6 +++
 kernel/sys.c                |   3 +-
 kernel/time/Makefile        |  10 +++-
 kernel/time/alarmtimer.c    |   6 ++-
 kernel/time/posix-stubs.c   | 123 ++++++++++++++++++++++++++++++++++++++++++++
 kernel/time/timer.c         |   3 +-
 security/selinux/hooks.c    |  11 ++--
 15 files changed, 200 insertions(+), 13 deletions(-)
 create mode 100644 kernel/time/posix-stubs.c

diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
index ffb93f499c..56e427c7aa 100644
--- a/arch/alpha/kernel/osf_sys.c
+++ b/arch/alpha/kernel/osf_sys.c
@@ -1029,11 +1029,16 @@ SYSCALL_DEFINE2(osf_settimeofday, struct timeval32 __user *, tv,
 	return do_sys_settimeofday(tv ? &kts : NULL, tz ? &ktz : NULL);
 }
 
+asmlinkage long sys_ni_posix_timers(void);
+
 SYSCALL_DEFINE2(osf_getitimer, int, which, struct itimerval32 __user *, it)
 {
 	struct itimerval kit;
 	int error;
 
+	if (!IS_ENABLED(CONFIG_POSIX_TIMERS))
+		return sys_ni_posix_timers();
+
 	error = do_getitimer(which, &kit);
 	if (!error && put_it32(it, &kit))
 		error = -EFAULT;
@@ -1047,6 +1052,9 @@ SYSCALL_DEFINE3(osf_setitimer, int, which, struct itimerval32 __user *, in,
 	struct itimerval kin, kout;
 	int error;
 
+	if (!IS_ENABLED(CONFIG_POSIX_TIMERS))
+		return sys_ni_posix_timers();
+
 	if (in) {
 		if (get_it32(&kin, in))
 			return -EFAULT;
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index dcc09739a5..45ba878ae0 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -542,6 +542,7 @@ config HANGCHECK_TIMER
 config MMTIMER
 	tristate "MMTIMER Memory mapped RTC for SGI Altix"
 	depends on IA64_GENERIC || IA64_SGI_SN2
+	depends on POSIX_TIMERS
 	default y
 	help
 	  The mmtimer device allows direct userspace access to the
diff --git a/drivers/ptp/Kconfig b/drivers/ptp/Kconfig
index 0f7492f8ea..bdce332911 100644
--- a/drivers/ptp/Kconfig
+++ b/drivers/ptp/Kconfig
@@ -6,7 +6,7 @@ menu "PTP clock support"
 
 config PTP_1588_CLOCK
 	tristate "PTP clock support"
-	depends on NET
+	depends on NET && POSIX_TIMERS
 	select PPS
 	select NET_PTP_CLASSIFY
 	help
diff --git a/fs/exec.c b/fs/exec.c
index 6fcfb3f7b1..a67a172332 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1164,8 +1164,10 @@ static int de_thread(struct task_struct *tsk)
 	/* we have changed execution domain */
 	tsk->exit_signal = SIGCHLD;
 
+#ifdef CONFIG_POSIX_TIMERS
 	exit_itimers(sig);
 	flush_itimer_signals();
+#endif
 
 	if (atomic_read(&oldsighand->count) != 1) {
 		struct sighand_struct *newsighand;
diff --git a/init/Kconfig b/init/Kconfig
index 34407f15e6..456e0b8912 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1445,6 +1445,23 @@ config SYSCTL_SYSCALL
 
 	  If unsure say N here.
 
+config POSIX_TIMERS
+	bool "Posix Clocks & timers" if EXPERT
+	default y
+	help
+	  This includes native support for POSIX timers to the kernel.
+	  Some embedded systems have no use for them and therefore they
+	  can be configured out to reduce the size of the kernel image.
+
+	  When this option is disabled, the following syscalls won't be
+	  available: timer_create, timer_gettime: timer_getoverrun,
+	  timer_settime, timer_delete, clock_adjtime, getitimer,
+	  setitimer, alarm. Furthermore, the clock_settime, clock_gettime,
+	  clock_getres and clock_nanosleep syscalls will be limited to
+	  CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only.
+
+	  If unsure say y.
+
 config KALLSYMS
 	 bool "Load all symbols for debugging/ksymoops" if EXPERT
 	 default y
diff --git a/kernel/compat.c b/kernel/compat.c
index 333d364be2..b3a047f208 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -307,12 +307,17 @@ static inline long put_compat_itimerval(struct compat_itimerval __user *o,
 		 __put_user(i->it_value.tv_usec, &o->it_value.tv_usec)));
 }
 
+asmlinkage long sys_ni_posix_timers(void);
+
 COMPAT_SYSCALL_DEFINE2(getitimer, int, which,
 		struct compat_itimerval __user *, it)
 {
 	struct itimerval kit;
 	int error;
 
+	if (!IS_ENABLED(CONFIG_POSIX_TIMERS))
+		return sys_ni_posix_timers();
+
 	error = do_getitimer(which, &kit);
 	if (!error && put_compat_itimerval(it, &kit))
 		error = -EFAULT;
@@ -326,6 +331,9 @@ COMPAT_SYSCALL_DEFINE3(setitimer, int, which,
 	struct itimerval kin, kout;
 	int error;
 
+	if (!IS_ENABLED(CONFIG_POSIX_TIMERS))
+		return sys_ni_posix_timers();
+
 	if (in) {
 		if (get_compat_itimerval(&kin, in))
 			return -EFAULT;
diff --git a/kernel/exit.c b/kernel/exit.c
index d16bcdd89d..684de019b6 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -92,11 +92,10 @@ static void __exit_signal(struct task_struct *tsk)
 					lockdep_tasklist_lock_is_held());
 	spin_lock(&sighand->siglock);
 
+#ifdef CONFIG_POSIX_TIMERS
 	posix_cpu_timers_exit(tsk);
 	if (group_dead) {
 		posix_cpu_timers_exit_group(tsk);
-		tty = sig->tty;
-		sig->tty = NULL;
 	} else {
 		/*
 		 * This can only happen if the caller is de_thread().
@@ -105,7 +104,13 @@ static void __exit_signal(struct task_struct *tsk)
 		 */
 		if (unlikely(has_group_leader_pid(tsk)))
 			posix_cpu_timers_exit_group(tsk);
+	}
+#endif
 
+	if (group_dead) {
+		tty = sig->tty;
+		sig->tty = NULL;
+	} else {
 		/*
 		 * If there is any task waiting for the group exit
 		 * then notify it:
@@ -803,8 +808,10 @@ void __noreturn do_exit(long code)
 	acct_update_integrals(tsk);
 	group_dead = atomic_dec_and_test(&tsk->signal->live);
 	if (group_dead) {
+#ifdef CONFIG_POSIX_TIMERS
 		hrtimer_cancel(&tsk->signal->real_timer);
 		exit_itimers(tsk->signal);
+#endif
 		if (tsk->mm)
 			setmax_mm_hiwater_rss(&tsk->signal->maxrss, tsk->mm);
 	}
diff --git a/kernel/fork.c b/kernel/fork.c
index 623259fc79..17da35fa77 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1342,8 +1342,10 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
 	seqlock_init(&sig->stats_lock);
 	prev_cputime_init(&sig->prev_cputime);
 
+#ifdef CONFIG_POSIX_TIMERS
 	hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	sig->real_timer.function = it_real_fn;
+#endif
 
 	task_lock(current->group_leader);
 	memcpy(sig->rlim, current->signal->rlim, sizeof sig->rlim);
diff --git a/kernel/signal.c b/kernel/signal.c
index 75761acc77..29a410780a 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -427,6 +427,7 @@ void flush_signals(struct task_struct *t)
 	spin_unlock_irqrestore(&t->sighand->siglock, flags);
 }
 
+#ifdef CONFIG_POSIX_TIMERS
 static void __flush_itimer_signals(struct sigpending *pending)
 {
 	sigset_t signal, retain;
@@ -460,6 +461,7 @@ void flush_itimer_signals(void)
 	__flush_itimer_signals(&tsk->signal->shared_pending);
 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
 }
+#endif
 
 void ignore_signals(struct task_struct *t)
 {
@@ -567,6 +569,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
 	if (!signr) {
 		signr = __dequeue_signal(&tsk->signal->shared_pending,
 					 mask, info);
+#ifdef CONFIG_POSIX_TIMERS
 		/*
 		 * itimer signal ?
 		 *
@@ -590,6 +593,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
 				hrtimer_restart(tmr);
 			}
 		}
+#endif
 	}
 
 	recalc_sigpending();
@@ -611,6 +615,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
 		 */
 		current->jobctl |= JOBCTL_STOP_DEQUEUED;
 	}
+#ifdef CONFIG_POSIX_TIMERS
 	if ((info->si_code & __SI_MASK) == __SI_TIMER && info->si_sys_private) {
 		/*
 		 * Release the siglock to ensure proper locking order
@@ -622,6 +627,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
 		do_schedule_next_timer(info);
 		spin_lock(&tsk->sighand->siglock);
 	}
+#endif
 	return signr;
 }
 
diff --git a/kernel/sys.c b/kernel/sys.c
index 89d5be4181..78c9fb7dd6 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1416,7 +1416,8 @@ int do_prlimit(struct task_struct *tsk, unsigned int resource,
 	 * applications, so we live with it
 	 */
 	 if (!retval && new_rlim && resource == RLIMIT_CPU &&
-			 new_rlim->rlim_cur != RLIM_INFINITY)
+	     new_rlim->rlim_cur != RLIM_INFINITY &&
+	     IS_ENABLED(CONFIG_POSIX_TIMERS))
 		update_rlimit_cpu(tsk, new_rlim->rlim_cur);
 out:
 	read_unlock(&tasklist_lock);
diff --git a/kernel/time/Makefile b/kernel/time/Makefile
index 49eca0beed..976840d29a 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 c3aad685bb..9a878eacf9 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -848,8 +848,10 @@ 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/posix-stubs.c b/kernel/time/posix-stubs.c
new file mode 100644
index 0000000000..cd6716e115
--- /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/timer.c b/kernel/time/timer.c
index 3ed6c67e17..099e43311f 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -1601,7 +1601,8 @@ 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);
 }
 
 /**
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 0850579362..d769a136ea 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2525,7 +2525,8 @@ static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
 			rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
 		}
 		task_unlock(current);
-		update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
+		if (IS_ENABLED(CONFIG_POSIX_TIMERS))
+			update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
 	}
 }
 
@@ -2555,9 +2556,11 @@ static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
 	 */
 	rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
 	if (rc) {
-		memset(&itimer, 0, sizeof itimer);
-		for (i = 0; i < 3; i++)
-			do_setitimer(i, &itimer, NULL);
+		if (IS_ENABLED(CONFIG_POSIX_TIMERS)) {
+			memset(&itimer, 0, sizeof itimer);
+			for (i = 0; i < 3; i++)
+				do_setitimer(i, &itimer, NULL);
+		}
 		spin_lock_irq(&current->sighand->siglock);
 		if (!fatal_signal_pending(current)) {
 			flush_sigqueue(&current->pending);
-- 
2.7.4

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#1523160 — Re: [PATCH v4 6/6] posix-timers: make it configurable

FromJohn Stultz <john.stultz@linaro.org>
Date2016-11-16 01:50 +0100
SubjectRe: [PATCH v4 6/6] posix-timers: make it configurable
Message-ID<sDWAh-3L5-7@gated-at.bofh.it>
In reply to#1519580
On Thu, Nov 10, 2016 at 9:10 PM, Nicolas Pitre <nicolas.pitre@linaro.org> wrote:
> Some embedded systems have no use for them.  This removes about
> 25KB from the kernel binary size when configured out.
>
> Corresponding syscalls are routed to a stub logging the attempt to
> use those syscalls which should be enough of a clue if they were
> disabled without proper consideration. They are: timer_create,
> timer_gettime: timer_getoverrun, timer_settime, timer_delete,
> clock_adjtime, setitimer, getitimer, alarm.
>
> The clock_settime, clock_gettime, clock_getres and clock_nanosleep
> syscalls are replaced by simple wrappers compatible with CLOCK_REALTIME,
> CLOCK_MONOTONIC and CLOCK_BOOTTIME only which should cover the vast
> majority of use cases with very little code.
>
> Signed-off-by: Nicolas Pitre <nico@linaro.org>
> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
> Acked-by: Richard Cochran <richardcochran@gmail.com>
> Acked-by: Thomas Gleixner <tglx@linutronix.de>

Ok.. ran the series through the kselftest/timers series and the results look ok.

Acked-by: John Stultz <john.stultz@linaro.org>

thanks
-john

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#1523300 — [tip:timers/core] posix-timers: Make them configurable

Fromtip-bot for Nicolas Pitre <tipbot@zytor.com>
Date2016-11-16 09:40 +0100
Subject[tip:timers/core] posix-timers: Make them configurable
Message-ID<sE3V8-rc-23@gated-at.bofh.it>
In reply to#1519580
Commit-ID:  baa73d9e478ff32d62f3f9422822b59dd9a95a21
Gitweb:     http://git.kernel.org/tip/baa73d9e478ff32d62f3f9422822b59dd9a95a21
Author:     Nicolas Pitre <nicolas.pitre@linaro.org>
AuthorDate: Fri, 11 Nov 2016 00:10:10 -0500
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Wed, 16 Nov 2016 09:26:35 +0100

posix-timers: Make them configurable

Some embedded systems have no use for them.  This removes about
25KB from the kernel binary size when configured out.

Corresponding syscalls are routed to a stub logging the attempt to
use those syscalls which should be enough of a clue if they were
disabled without proper consideration. They are: timer_create,
timer_gettime: timer_getoverrun, timer_settime, timer_delete,
clock_adjtime, setitimer, getitimer, alarm.

The clock_settime, clock_gettime, clock_getres and clock_nanosleep
syscalls are replaced by simple wrappers compatible with CLOCK_REALTIME,
CLOCK_MONOTONIC and CLOCK_BOOTTIME only which should cover the vast
majority of use cases with very little code.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: linux-kbuild@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: Michal Marek <mmarek@suse.com>
Cc: Edward Cree <ecree@solarflare.com>
Link: http://lkml.kernel.org/r/1478841010-28605-7-git-send-email-nicolas.pitre@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 arch/alpha/kernel/osf_sys.c |   8 +++
 drivers/char/Kconfig        |   1 +
 drivers/ptp/Kconfig         |   2 +-
 fs/exec.c                   |   2 +
 init/Kconfig                |  17 ++++++
 kernel/compat.c             |   8 +++
 kernel/exit.c               |  11 +++-
 kernel/fork.c               |   2 +
 kernel/signal.c             |   6 +++
 kernel/sys.c                |   3 +-
 kernel/time/Makefile        |  10 +++-
 kernel/time/alarmtimer.c    |   6 ++-
 kernel/time/posix-stubs.c   | 123 ++++++++++++++++++++++++++++++++++++++++++++
 kernel/time/timer.c         |   3 +-
 security/selinux/hooks.c    |  11 ++--
 15 files changed, 200 insertions(+), 13 deletions(-)

diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
index ffb93f49..56e427c 100644
--- a/arch/alpha/kernel/osf_sys.c
+++ b/arch/alpha/kernel/osf_sys.c
@@ -1029,11 +1029,16 @@ SYSCALL_DEFINE2(osf_settimeofday, struct timeval32 __user *, tv,
 	return do_sys_settimeofday(tv ? &kts : NULL, tz ? &ktz : NULL);
 }
 
+asmlinkage long sys_ni_posix_timers(void);
+
 SYSCALL_DEFINE2(osf_getitimer, int, which, struct itimerval32 __user *, it)
 {
 	struct itimerval kit;
 	int error;
 
+	if (!IS_ENABLED(CONFIG_POSIX_TIMERS))
+		return sys_ni_posix_timers();
+
 	error = do_getitimer(which, &kit);
 	if (!error && put_it32(it, &kit))
 		error = -EFAULT;
@@ -1047,6 +1052,9 @@ SYSCALL_DEFINE3(osf_setitimer, int, which, struct itimerval32 __user *, in,
 	struct itimerval kin, kout;
 	int error;
 
+	if (!IS_ENABLED(CONFIG_POSIX_TIMERS))
+		return sys_ni_posix_timers();
+
 	if (in) {
 		if (get_it32(&kin, in))
 			return -EFAULT;
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index dcc0973..45ba878 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -542,6 +542,7 @@ config HANGCHECK_TIMER
 config MMTIMER
 	tristate "MMTIMER Memory mapped RTC for SGI Altix"
 	depends on IA64_GENERIC || IA64_SGI_SN2
+	depends on POSIX_TIMERS
 	default y
 	help
 	  The mmtimer device allows direct userspace access to the
diff --git a/drivers/ptp/Kconfig b/drivers/ptp/Kconfig
index 0f7492f..bdce332 100644
--- a/drivers/ptp/Kconfig
+++ b/drivers/ptp/Kconfig
@@ -6,7 +6,7 @@ menu "PTP clock support"
 
 config PTP_1588_CLOCK
 	tristate "PTP clock support"
-	depends on NET
+	depends on NET && POSIX_TIMERS
 	select PPS
 	select NET_PTP_CLASSIFY
 	help
diff --git a/fs/exec.c b/fs/exec.c
index 4e497b9..923c57d 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1169,8 +1169,10 @@ no_thread_group:
 	/* we have changed execution domain */
 	tsk->exit_signal = SIGCHLD;
 
+#ifdef CONFIG_POSIX_TIMERS
 	exit_itimers(sig);
 	flush_itimer_signals();
+#endif
 
 	if (atomic_read(&oldsighand->count) != 1) {
 		struct sighand_struct *newsighand;
diff --git a/init/Kconfig b/init/Kconfig
index 34407f1..456e0b8 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1445,6 +1445,23 @@ config SYSCTL_SYSCALL
 
 	  If unsure say N here.
 
+config POSIX_TIMERS
+	bool "Posix Clocks & timers" if EXPERT
+	default y
+	help
+	  This includes native support for POSIX timers to the kernel.
+	  Some embedded systems have no use for them and therefore they
+	  can be configured out to reduce the size of the kernel image.
+
+	  When this option is disabled, the following syscalls won't be
+	  available: timer_create, timer_gettime: timer_getoverrun,
+	  timer_settime, timer_delete, clock_adjtime, getitimer,
+	  setitimer, alarm. Furthermore, the clock_settime, clock_gettime,
+	  clock_getres and clock_nanosleep syscalls will be limited to
+	  CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only.
+
+	  If unsure say y.
+
 config KALLSYMS
 	 bool "Load all symbols for debugging/ksymoops" if EXPERT
 	 default y
diff --git a/kernel/compat.c b/kernel/compat.c
index 333d364..b3a047f 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -307,12 +307,17 @@ static inline long put_compat_itimerval(struct compat_itimerval __user *o,
 		 __put_user(i->it_value.tv_usec, &o->it_value.tv_usec)));
 }
 
+asmlinkage long sys_ni_posix_timers(void);
+
 COMPAT_SYSCALL_DEFINE2(getitimer, int, which,
 		struct compat_itimerval __user *, it)
 {
 	struct itimerval kit;
 	int error;
 
+	if (!IS_ENABLED(CONFIG_POSIX_TIMERS))
+		return sys_ni_posix_timers();
+
 	error = do_getitimer(which, &kit);
 	if (!error && put_compat_itimerval(it, &kit))
 		error = -EFAULT;
@@ -326,6 +331,9 @@ COMPAT_SYSCALL_DEFINE3(setitimer, int, which,
 	struct itimerval kin, kout;
 	int error;
 
+	if (!IS_ENABLED(CONFIG_POSIX_TIMERS))
+		return sys_ni_posix_timers();
+
 	if (in) {
 		if (get_compat_itimerval(&kin, in))
 			return -EFAULT;
diff --git a/kernel/exit.c b/kernel/exit.c
index d16bcdd..684de01 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -92,11 +92,10 @@ static void __exit_signal(struct task_struct *tsk)
 					lockdep_tasklist_lock_is_held());
 	spin_lock(&sighand->siglock);
 
+#ifdef CONFIG_POSIX_TIMERS
 	posix_cpu_timers_exit(tsk);
 	if (group_dead) {
 		posix_cpu_timers_exit_group(tsk);
-		tty = sig->tty;
-		sig->tty = NULL;
 	} else {
 		/*
 		 * This can only happen if the caller is de_thread().
@@ -105,7 +104,13 @@ static void __exit_signal(struct task_struct *tsk)
 		 */
 		if (unlikely(has_group_leader_pid(tsk)))
 			posix_cpu_timers_exit_group(tsk);
+	}
+#endif
 
+	if (group_dead) {
+		tty = sig->tty;
+		sig->tty = NULL;
+	} else {
 		/*
 		 * If there is any task waiting for the group exit
 		 * then notify it:
@@ -803,8 +808,10 @@ void __noreturn do_exit(long code)
 	acct_update_integrals(tsk);
 	group_dead = atomic_dec_and_test(&tsk->signal->live);
 	if (group_dead) {
+#ifdef CONFIG_POSIX_TIMERS
 		hrtimer_cancel(&tsk->signal->real_timer);
 		exit_itimers(tsk->signal);
+#endif
 		if (tsk->mm)
 			setmax_mm_hiwater_rss(&tsk->signal->maxrss, tsk->mm);
 	}
diff --git a/kernel/fork.c b/kernel/fork.c
index 623259f..17da35f 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1342,8 +1342,10 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
 	seqlock_init(&sig->stats_lock);
 	prev_cputime_init(&sig->prev_cputime);
 
+#ifdef CONFIG_POSIX_TIMERS
 	hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	sig->real_timer.function = it_real_fn;
+#endif
 
 	task_lock(current->group_leader);
 	memcpy(sig->rlim, current->signal->rlim, sizeof sig->rlim);
diff --git a/kernel/signal.c b/kernel/signal.c
index 75761ac..29a4107 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -427,6 +427,7 @@ void flush_signals(struct task_struct *t)
 	spin_unlock_irqrestore(&t->sighand->siglock, flags);
 }
 
+#ifdef CONFIG_POSIX_TIMERS
 static void __flush_itimer_signals(struct sigpending *pending)
 {
 	sigset_t signal, retain;
@@ -460,6 +461,7 @@ void flush_itimer_signals(void)
 	__flush_itimer_signals(&tsk->signal->shared_pending);
 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
 }
+#endif
 
 void ignore_signals(struct task_struct *t)
 {
@@ -567,6 +569,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
 	if (!signr) {
 		signr = __dequeue_signal(&tsk->signal->shared_pending,
 					 mask, info);
+#ifdef CONFIG_POSIX_TIMERS
 		/*
 		 * itimer signal ?
 		 *
@@ -590,6 +593,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
 				hrtimer_restart(tmr);
 			}
 		}
+#endif
 	}
 
 	recalc_sigpending();
@@ -611,6 +615,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
 		 */
 		current->jobctl |= JOBCTL_STOP_DEQUEUED;
 	}
+#ifdef CONFIG_POSIX_TIMERS
 	if ((info->si_code & __SI_MASK) == __SI_TIMER && info->si_sys_private) {
 		/*
 		 * Release the siglock to ensure proper locking order
@@ -622,6 +627,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
 		do_schedule_next_timer(info);
 		spin_lock(&tsk->sighand->siglock);
 	}
+#endif
 	return signr;
 }
 
diff --git a/kernel/sys.c b/kernel/sys.c
index 89d5be4..78c9fb7 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1416,7 +1416,8 @@ int do_prlimit(struct task_struct *tsk, unsigned int resource,
 	 * applications, so we live with it
 	 */
 	 if (!retval && new_rlim && resource == RLIMIT_CPU &&
-			 new_rlim->rlim_cur != RLIM_INFINITY)
+	     new_rlim->rlim_cur != RLIM_INFINITY &&
+	     IS_ENABLED(CONFIG_POSIX_TIMERS))
 		update_rlimit_cpu(tsk, new_rlim->rlim_cur);
 out:
 	read_unlock(&tasklist_lock);
diff --git a/kernel/time/Makefile b/kernel/time/Makefile
index 49eca0b..976840d 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 12dd190..a15caa3 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -846,8 +846,10 @@ 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/posix-stubs.c b/kernel/time/posix-stubs.c
new file mode 100644
index 0000000..cd6716e
--- /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/timer.c b/kernel/time/timer.c
index 42d27aa..e2892e4 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -1601,7 +1601,8 @@ 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);
 }
 
 /**
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 09fd610..38b79d7 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2525,7 +2525,8 @@ static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
 			rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
 		}
 		task_unlock(current);
-		update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
+		if (IS_ENABLED(CONFIG_POSIX_TIMERS))
+			update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
 	}
 }
 
@@ -2555,9 +2556,11 @@ static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
 	 */
 	rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
 	if (rc) {
-		memset(&itimer, 0, sizeof itimer);
-		for (i = 0; i < 3; i++)
-			do_setitimer(i, &itimer, NULL);
+		if (IS_ENABLED(CONFIG_POSIX_TIMERS)) {
+			memset(&itimer, 0, sizeof itimer);
+			for (i = 0; i < 3; i++)
+				do_setitimer(i, &itimer, NULL);
+		}
 		spin_lock_irq(&current->sighand->siglock);
 		if (!fatal_signal_pending(current)) {
 			flush_sigqueue(&current->pending);

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