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: releng/11.0/lib/libc/i386/gen/getcontextx.c 251047 2013-05-28 04:54:16Z kib $");
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/npx.h>
36#include <machine/specialreg.h>
37#include <machine/sysarch.h>
38
39static int xstate_sz = -1;
40
41int
42__getcontextx_size(void)
43{
44	u_int p[4];
45	int cpuid_supported;
46
47	if (xstate_sz == -1) {
48		__asm __volatile(
49		    "	pushfl\n"
50		    "	popl	%%eax\n"
51		    "	movl    %%eax,%%ecx\n"
52		    "	xorl    $0x200000,%%eax\n"
53		    "	pushl	%%eax\n"
54		    "	popfl\n"
55		    "	pushfl\n"
56		    "	popl    %%eax\n"
57		    "	xorl    %%eax,%%ecx\n"
58		    "	je	1f\n"
59		    "	movl	$1,%0\n"
60		    "	jmp	2f\n"
61		    "1:	movl	$0,%0\n"
62		    "2:\n"
63		    : "=r" (cpuid_supported) : : "eax", "ecx");
64		if (cpuid_supported) {
65			__asm __volatile(
66			    "	pushl	%%ebx\n"
67			    "	cpuid\n"
68			    "	movl	%%ebx,%1\n"
69			    "	popl	%%ebx\n"
70			    : "=a" (p[0]), "=r" (p[1]), "=c" (p[2]), "=d" (p[3])
71			    :  "0" (0x1));
72			if ((p[2] & CPUID2_OSXSAVE) != 0) {
73				__asm __volatile(
74				    "	pushl	%%ebx\n"
75				    "	cpuid\n"
76				    "	movl	%%ebx,%1\n"
77				    "	popl	%%ebx\n"
78				    : "=a" (p[0]), "=r" (p[1]), "=c" (p[2]),
79					"=d" (p[3])
80				    :  "0" (0xd), "2" (0x0));
81				xstate_sz = p[1] - sizeof(struct savexmm);
82			} else
83				xstate_sz = 0;
84		} else
85			xstate_sz = 0;
86	}
87
88	return (sizeof(ucontext_t) + xstate_sz);
89}
90
91int
92__fillcontextx2(char *ctx)
93{
94	struct i386_get_xfpustate xfpu;
95	ucontext_t *ucp;
96
97	ucp = (ucontext_t *)ctx;
98	if (xstate_sz != 0) {
99		xfpu.addr = (char *)(ucp + 1);
100		xfpu.len = xstate_sz;
101		if (sysarch(I386_GET_XFPUSTATE, &xfpu) == -1)
102			return (-1);
103		ucp->uc_mcontext.mc_xfpustate = (__register_t)xfpu.addr;
104		ucp->uc_mcontext.mc_xfpustate_len = xstate_sz;
105		ucp->uc_mcontext.mc_flags |= _MC_HASFPXSTATE;
106	} else {
107		ucp->uc_mcontext.mc_xfpustate = 0;
108		ucp->uc_mcontext.mc_xfpustate_len = 0;
109	}
110	return (0);
111}
112
113int
114__fillcontextx(char *ctx)
115{
116	ucontext_t *ucp;
117
118	ucp = (ucontext_t *)ctx;
119	if (getcontext(ucp) == -1)
120		return (-1);
121	__fillcontextx2(ctx);
122	return (0);
123}
124
125__weak_reference(__getcontextx, getcontextx);
126
127ucontext_t *
128__getcontextx(void)
129{
130	char *ctx;
131	int error;
132
133	ctx = malloc(__getcontextx_size());
134	if (ctx == NULL)
135		return (NULL);
136	if (__fillcontextx(ctx) == -1) {
137		error = errno;
138		free(ctx);
139		errno = error;
140		return (NULL);
141	}
142	return ((ucontext_t *)ctx);
143}
144