1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2011 Konstantin Belousov <kib@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31
32#include <sys/types.h>
33#include <sys/ucontext.h>
34#include <errno.h>
35#include <stdarg.h>
36#include <stdlib.h>
37#include <machine/cpufunc.h>
38#include <machine/specialreg.h>
39#include <machine/sysarch.h>
40#include <x86/ifunc.h>
41#include <x86/fpu.h>
42
43#if defined __i386__
44#define	X86_GET_XFPUSTATE	I386_GET_XFPUSTATE
45typedef struct savexmm savex86_t ;
46typedef struct i386_get_xfpustate x86_get_xfpustate_t;
47#elif defined __amd64__
48#define	X86_GET_XFPUSTATE	AMD64_GET_XFPUSTATE
49typedef struct savefpu savex86_t;
50typedef struct amd64_get_xfpustate x86_get_xfpustate_t;
51#else
52#error "Wrong arch"
53#endif
54
55static int xstate_sz = 0;
56
57static int
58__getcontextx_size_xfpu(void)
59{
60
61	return (sizeof(ucontext_t) + xstate_sz);
62}
63
64DEFINE_UIFUNC(, int, __getcontextx_size, (void))
65{
66	u_int p[4];
67
68	if ((cpu_feature2 & CPUID2_OSXSAVE) != 0) {
69		cpuid_count(0xd, 0x0, p);
70		xstate_sz = p[1] - sizeof(savex86_t);
71	}
72	return (__getcontextx_size_xfpu);
73}
74
75static int
76__fillcontextx2_xfpu(char *ctx)
77{
78	x86_get_xfpustate_t xfpu;
79	ucontext_t *ucp;
80
81	ucp = (ucontext_t *)ctx;
82	xfpu.addr = (char *)(ucp + 1);
83	xfpu.len = xstate_sz;
84	if (sysarch(X86_GET_XFPUSTATE, &xfpu) == -1)
85		return (-1);
86	ucp->uc_mcontext.mc_xfpustate = (__register_t)xfpu.addr;
87	ucp->uc_mcontext.mc_xfpustate_len = xstate_sz;
88	ucp->uc_mcontext.mc_flags |= _MC_HASFPXSTATE;
89	return (0);
90}
91
92static int
93__fillcontextx2_noxfpu(char *ctx)
94{
95	ucontext_t *ucp;
96
97	ucp = (ucontext_t *)ctx;
98	ucp->uc_mcontext.mc_xfpustate = 0;
99	ucp->uc_mcontext.mc_xfpustate_len = 0;
100	return (0);
101}
102
103DEFINE_UIFUNC(, int, __fillcontextx2, (char *))
104{
105
106	return ((cpu_feature2 & CPUID2_OSXSAVE) != 0 ? __fillcontextx2_xfpu :
107	    __fillcontextx2_noxfpu);
108}
109
110int
111__fillcontextx(char *ctx)
112{
113	ucontext_t *ucp;
114
115	ucp = (ucontext_t *)ctx;
116	if (getcontext(ucp) == -1)
117		return (-1);
118	__fillcontextx2(ctx);
119	return (0);
120}
121
122__weak_reference(__getcontextx, getcontextx);
123
124ucontext_t *
125__getcontextx(void)
126{
127	char *ctx;
128	int error;
129
130	ctx = malloc(__getcontextx_size());
131	if (ctx == NULL)
132		return (NULL);
133	if (__fillcontextx(ctx) == -1) {
134		error = errno;
135		free(ctx);
136		errno = error;
137		return (NULL);
138	}
139	return ((ucontext_t *)ctx);
140}
141