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
42 typedef struct savexmm savex86_t ;
43 typedef struct i386_get_xfpustate x86_get_xfpustate_t;
44 #elif defined __amd64__
45 #define X86_GET_XFPUSTATE AMD64_GET_XFPUSTATE
46 typedef struct savefpu savex86_t;
47 typedef struct amd64_get_xfpustate x86_get_xfpustate_t;
48 #else
49 #error "Wrong arch"
50 #endif
51
52 static int xstate_sz = 0;
53
54 static int
__getcontextx_size_xfpu(void)55 __getcontextx_size_xfpu(void)
56 {
57
58 return (sizeof(ucontext_t) + xstate_sz);
59 }
60
61 DEFINE_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
72 static int
__fillcontextx2_xfpu(char * ctx)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
89 static int
__fillcontextx2_noxfpu(char * ctx)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
100 DEFINE_UIFUNC(, int, __fillcontextx2, (char *))
101 {
102
103 return ((cpu_feature2 & CPUID2_OSXSAVE) != 0 ? __fillcontextx2_xfpu :
104 __fillcontextx2_noxfpu);
105 }
106
107 int
__fillcontextx(char * ctx)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
121 ucontext_t *
__getcontextx(void)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