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/*-
* 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;
#pragma weak __vdso_gettimeofday
int
__vdso_gettimeofday(struct timeval *tv, struct timezone *tz)
{
struct bintime bt;
int error;
if (tz != NULL)
return (ENOSYS);
if (tk == NULL) {
error = __vdso_gettimekeep(&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);
}
#pragma weak __vdso_clock_gettime
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);
}
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