1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
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/types.h>
30#include <sys/ucontext.h>
31#include <errno.h>
32#include <stdarg.h>
33#include <stdlib.h>
34#include <machine/cpufunc.h>
35#include <machine/specialreg.h>
36#include <machine/sysarch.h>
37#include <x86/ifunc.h>
38#include <x86/fpu.h>
39
40#if defined __i386__
41#define	X86_GET_XFPUSTATE	I386_GET_XFPUSTATE
42typedef struct savexmm savex86_t ;
43typedef struct i386_get_xfpustate x86_get_xfpustate_t;
44#elif defined __amd64__
45#define	X86_GET_XFPUSTATE	AMD64_GET_XFPUSTATE
46typedef struct savefpu savex86_t;
47typedef struct amd64_get_xfpustate x86_get_xfpustate_t;
48#else
49#error "Wrong arch"
50#endif
51
52static int xstate_sz = 0;
53
54static int
55__getcontextx_size_xfpu(void)
56{
57
58	return (sizeof(ucontext_t) + xstate_sz);
59}
60
61DEFINE_UIFUNC(, int, __getcontextx_size, (void))
62{
63	u_int p[4];
64
65	if ((cpu_feature2 & CPUID2_OSXSAVE) != 0) {
66		cpuid_count(0xd, 0x0, p);
67		xstate_sz = p[1] - sizeof(savex86_t);
68	}
69	return (__getcontextx_size_xfpu);
70}
71
72static int
73__fillcontextx2_xfpu(char *ctx)
74{
75	x86_get_xfpustate_t xfpu;
76	ucontext_t *ucp;
77
78	ucp = (ucontext_t *)ctx;
79	xfpu.addr = (char *)(ucp + 1);
80	xfpu.len = xstate_sz;
81	if (sysarch(X86_GET_XFPUSTATE, &xfpu) == -1)
82		return (-1);
83	ucp->uc_mcontext.mc_xfpustate = (__register_t)xfpu.addr;
84	ucp->uc_mcontext.mc_xfpustate_len = xstate_sz;
85	ucp->uc_mcontext.mc_flags |= _MC_HASFPXSTATE;
86	return (0);
87}
88
89static int
90__fillcontextx2_noxfpu(char *ctx)
91{
92	ucontext_t *ucp;
93
94	ucp = (ucontext_t *)ctx;
95	ucp->uc_mcontext.mc_xfpustate = 0;
96	ucp->uc_mcontext.mc_xfpustate_len = 0;
97	return (0);
98}
99
100DEFINE_UIFUNC(, int, __fillcontextx2, (char *))
101{
102
103	return ((cpu_feature2 & CPUID2_OSXSAVE) != 0 ? __fillcontextx2_xfpu :
104	    __fillcontextx2_noxfpu);
105}
106
107int
108__fillcontextx(char *ctx)
109{
110	ucontext_t *ucp;
111
112	ucp = (ucontext_t *)ctx;
113	if (getcontext(ucp) == -1)
114		return (-1);
115	__fillcontextx2(ctx);
116	return (0);
117}
118
119__weak_reference(__getcontextx, getcontextx);
120
121ucontext_t *
122__getcontextx(void)
123{
124	char *ctx;
125	int error;
126
127	ctx = malloc(__getcontextx_size());
128	if (ctx == NULL)
129		return (NULL);
130	if (__fillcontextx(ctx) == -1) {
131		error = errno;
132		free(ctx);
133		errno = error;
134		return (NULL);
135	}
136	return ((ucontext_t *)ctx);
137}
138