v4.19.13 snapshot.
diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c
new file mode 100644
index 0000000..2c6847d
--- /dev/null
+++ b/kernel/time/posix-stubs.c
@@ -0,0 +1,239 @@
+/*
+ * 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>
+#include <linux/compat.h>
+
+#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
+/* Architectures may override SYS_NI and COMPAT_SYS_NI */
+#include <asm/syscall_wrapper.h>
+#endif
+
+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;
+}
+
+#ifndef SYS_NI
+#define SYS_NI(name) SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers)
+#endif
+
+#ifndef COMPAT_SYS_NI
+#define COMPAT_SYS_NI(name) SYSCALL_ALIAS(compat_sys_##name, sys_ni_posix_timers)
+#endif
+
+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 __kernel_timespec __user *, tp)
+{
+ struct timespec64 new_tp;
+
+ if (which_clock != CLOCK_REALTIME)
+ return -EINVAL;
+ if (get_timespec64(&new_tp, tp))
+ return -EFAULT;
+
+ return do_sys_settimeofday64(&new_tp, NULL);
+}
+
+int do_clock_gettime(clockid_t which_clock, struct timespec64 *tp)
+{
+ switch (which_clock) {
+ case CLOCK_REALTIME:
+ ktime_get_real_ts64(tp);
+ break;
+ case CLOCK_MONOTONIC:
+ ktime_get_ts64(tp);
+ break;
+ case CLOCK_BOOTTIME:
+ ktime_get_boottime_ts64(tp);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
+ struct __kernel_timespec __user *, tp)
+{
+ int ret;
+ struct timespec64 kernel_tp;
+
+ ret = do_clock_gettime(which_clock, &kernel_tp);
+ if (ret)
+ return ret;
+
+ if (put_timespec64(&kernel_tp, tp))
+ return -EFAULT;
+ return 0;
+}
+
+SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock, struct __kernel_timespec __user *, tp)
+{
+ struct timespec64 rtn_tp = {
+ .tv_sec = 0,
+ .tv_nsec = hrtimer_resolution,
+ };
+
+ switch (which_clock) {
+ case CLOCK_REALTIME:
+ case CLOCK_MONOTONIC:
+ case CLOCK_BOOTTIME:
+ if (put_timespec64(&rtn_tp, tp))
+ return -EFAULT;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
+ const struct __kernel_timespec __user *, rqtp,
+ struct __kernel_timespec __user *, rmtp)
+{
+ struct timespec64 t;
+
+ switch (which_clock) {
+ case CLOCK_REALTIME:
+ case CLOCK_MONOTONIC:
+ case CLOCK_BOOTTIME:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (get_timespec64(&t, rqtp))
+ return -EFAULT;
+ if (!timespec64_valid(&t))
+ return -EINVAL;
+ if (flags & TIMER_ABSTIME)
+ rmtp = NULL;
+ current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
+ current->restart_block.nanosleep.rmtp = rmtp;
+ return hrtimer_nanosleep(&t, flags & TIMER_ABSTIME ?
+ HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
+ which_clock);
+}
+
+#ifdef CONFIG_COMPAT
+COMPAT_SYS_NI(timer_create);
+COMPAT_SYS_NI(clock_adjtime);
+COMPAT_SYS_NI(timer_settime);
+COMPAT_SYS_NI(timer_gettime);
+COMPAT_SYS_NI(getitimer);
+COMPAT_SYS_NI(setitimer);
+#endif
+
+#ifdef CONFIG_COMPAT_32BIT_TIME
+COMPAT_SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
+ struct compat_timespec __user *, tp)
+{
+ struct timespec64 new_tp;
+
+ if (which_clock != CLOCK_REALTIME)
+ return -EINVAL;
+ if (compat_get_timespec64(&new_tp, tp))
+ return -EFAULT;
+
+ return do_sys_settimeofday64(&new_tp, NULL);
+}
+
+COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t, which_clock,
+ struct compat_timespec __user *, tp)
+{
+ int ret;
+ struct timespec64 kernel_tp;
+
+ ret = do_clock_gettime(which_clock, &kernel_tp);
+ if (ret)
+ return ret;
+
+ if (compat_put_timespec64(&kernel_tp, tp))
+ return -EFAULT;
+ return 0;
+}
+
+COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
+ struct compat_timespec __user *, tp)
+{
+ struct timespec64 rtn_tp = {
+ .tv_sec = 0,
+ .tv_nsec = hrtimer_resolution,
+ };
+
+ switch (which_clock) {
+ case CLOCK_REALTIME:
+ case CLOCK_MONOTONIC:
+ case CLOCK_BOOTTIME:
+ if (compat_put_timespec64(&rtn_tp, tp))
+ return -EFAULT;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
+ struct compat_timespec __user *, rqtp,
+ struct compat_timespec __user *, rmtp)
+{
+ struct timespec64 t;
+
+ switch (which_clock) {
+ case CLOCK_REALTIME:
+ case CLOCK_MONOTONIC:
+ case CLOCK_BOOTTIME:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (compat_get_timespec64(&t, rqtp))
+ return -EFAULT;
+ if (!timespec64_valid(&t))
+ return -EINVAL;
+ if (flags & TIMER_ABSTIME)
+ rmtp = NULL;
+ current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
+ current->restart_block.nanosleep.compat_rmtp = rmtp;
+ return hrtimer_nanosleep(&t, flags & TIMER_ABSTIME ?
+ HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
+ which_clock);
+}
+#endif