1 files changed, 142 insertions, 0 deletions
diff --git a/lib/libc/sys/__vdso_gettimeofday.c b/lib/libc/sys/__vdso_gettimeofday.c
new file mode 100644
index 0000000..32abb69
--- /dev/null
+++ b/lib/libc/sys/__vdso_gettimeofday.c
@@ -0,0 +1,142 @@
+/*-
+ * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/elf.h>
+#include <sys/time.h>
+#include <sys/vdso.h>
+#include <errno.h>
+#include <time.h>
+#include <machine/atomic.h>
+#include "libc_private.h"
+
+static u_int
+tc_delta(const struct vdso_timehands *th)
+{
+
+	return ((__vdso_gettc(th) - th->th_offset_count) &
+	    th->th_counter_mask);
+}
+
+static int
+binuptime(struct bintime *bt, struct vdso_timekeep *tk, int abs)
+{
+	struct vdso_timehands *th;
+	uint32_t curr, gen;
+
+	do {
+		if (!tk->tk_enabled)
+			return (ENOSYS);
+
+		/*
+		 * XXXKIB. The load of tk->tk_current should use
+		 * atomic_load_acq_32 to provide load barrier. But
+		 * since tk points to r/o mapped page, x86
+		 * implementation of atomic_load_acq faults.
+		 */
+		curr = tk->tk_current;
+		rmb();
+		th = &tk->tk_th[curr];
+		if (th->th_algo != VDSO_TH_ALGO_1)
+			return (ENOSYS);
+		gen = th->th_gen;
+		*bt = th->th_offset;
+		bintime_addx(bt, th->th_scale * tc_delta(th));
+		if (abs)
+			bintime_add(bt, &th->th_boottime);
+
+		/*
+		 * Barrier for load of both tk->tk_current and th->th_gen.
+		 */
+		rmb();
+	} while (curr != tk->tk_current || gen == 0 || gen != th->th_gen);
+	return (0);
+}
+
+static struct vdso_timekeep *tk;
+
+int
+__vdso_gettimeofday(struct timeval *tv, struct timezone *tz)
+{
+	struct bintime bt;
+	int error;
+
+	if (tz != NULL)
+		return (ENOSYS);
+	if (tk == NULL) {
+		error = _elf_aux_info(AT_TIMEKEEP, &tk, sizeof(tk));
+		if (error != 0 || tk == NULL)
+			return (ENOSYS);
+	}
+	if (tk->tk_ver != VDSO_TK_VER_CURR)
+		return (ENOSYS);
+	error = binuptime(&bt, tk, 1);
+	if (error != 0)
+		return (error);
+	bintime2timeval(&bt, tv);
+	return (0);
+}
+
+int
+__vdso_clock_gettime(clockid_t clock_id, struct timespec *ts)
+{
+	struct bintime bt;
+	int abs, error;
+
+	if (tk == NULL) {
+		error = _elf_aux_info(AT_TIMEKEEP, &tk, sizeof(tk));
+		if (error != 0 || tk == NULL)
+			return (ENOSYS);
+	}
+	if (tk->tk_ver != VDSO_TK_VER_CURR)
+		return (ENOSYS);
+	switch (clock_id) {
+	case CLOCK_REALTIME:
+	case CLOCK_REALTIME_PRECISE:
+	case CLOCK_REALTIME_FAST:
+	case CLOCK_SECOND:
+		abs = 1;
+		break;
+	case CLOCK_MONOTONIC:
+	case CLOCK_MONOTONIC_PRECISE:
+	case CLOCK_MONOTONIC_FAST:
+	case CLOCK_UPTIME:
+	case CLOCK_UPTIME_PRECISE:
+	case CLOCK_UPTIME_FAST:
+		abs = 0;
+		break;
+	default:
+		return (ENOSYS);
+	}
+	error = binuptime(&bt, tk, abs);
+	if (error != 0)
+		return (error);
+	bintime2timespec(&bt, ts);
+	if (clock_id == CLOCK_SECOND)
+		ts->tv_nsec = 0;
+	return (0);
+}