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