1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2011 Konstantin Belousov <[email protected]>
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
45 typedef struct savexmm savex86_t ;
46 typedef struct i386_get_xfpustate x86_get_xfpustate_t;
47 #elif defined __amd64__
48 #define X86_GET_XFPUSTATE AMD64_GET_XFPUSTATE
49 typedef struct savefpu savex86_t;
50 typedef struct amd64_get_xfpustate x86_get_xfpustate_t;
51 #else
52 #error "Wrong arch"
53 #endif
54
55 static int xstate_sz = 0;
56
57 static int
__getcontextx_size_xfpu(void)58 __getcontextx_size_xfpu(void)
59 {
60
61 return (sizeof(ucontext_t) + xstate_sz);
62 }
63
64 DEFINE_UIFUNC(, int, __getcontextx_size, (void), static)
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
75 static int
__fillcontextx2_xfpu(char * ctx)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
92 static int
__fillcontextx2_noxfpu(char * ctx)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
103 DEFINE_UIFUNC(, int, __fillcontextx2, (char *), static)
104 {
105
106 return ((cpu_feature2 & CPUID2_OSXSAVE) != 0 ? __fillcontextx2_xfpu :
107 __fillcontextx2_noxfpu);
108 }
109
110 int
__fillcontextx(char * ctx)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
124 ucontext_t *
__getcontextx(void)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