1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2003 Peter Wemm
5 * Copyright (c) 2017, 2018 The FreeBSD Foundation
6 * All rights reserved.
7 *
8 * Portions of this software were developed by Konstantin Belousov
9 * under sponsorship from the FreeBSD Foundation.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD$");
35
36#define	IN_RTLD	1
37#include <sys/param.h>
38#undef IN_RTLD
39#include <machine/cpufunc.h>
40#include <machine/specialreg.h>
41#include <machine/sysarch.h>
42#include <x86/ifunc.h>
43#include "libc_private.h"
44
45static int
46amd64_get_fsbase_cpu(void **addr)
47{
48
49	*addr = (void *)rdfsbase();
50	return (0);
51}
52
53static int
54amd64_get_fsbase_syscall(void **addr)
55{
56
57	return (sysarch(AMD64_GET_FSBASE, addr));
58}
59
60DEFINE_UIFUNC(, int, amd64_get_fsbase, (void **), static)
61{
62
63	if (__getosreldate() >= P_OSREL_WRFSBASE &&
64	    (cpu_stdext_feature & CPUID_STDEXT_FSGSBASE) != 0)
65		return (amd64_get_fsbase_cpu);
66	return (amd64_get_fsbase_syscall);
67}
68