1/* $NetBSD: mcontext.h,v 1.19.2.1 2026/07/19 15:57:27 martin Exp $ */
2
3/*-
4 * Copyright (c) 1999 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Klaus Klein.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#ifndef _I386_MCONTEXT_H_
33#define _I386_MCONTEXT_H_
34
35
36/*
37 * mcontext extensions to handle signal delivery.
38 */
39#define _UC_SETSTACK _UC_MD_BIT16
40#define _UC_CLRSTACK _UC_MD_BIT17
41#define _UC_VM _UC_MD_BIT18
42#define _UC_TLSBASE _UC_MD_BIT19
43#define _UC_XSAVE _UC_MD_BIT20
44
45/*
46 * Layout of mcontext_t according to the System V Application Binary Interface,
47 * Intel386(tm) Architecture Processor Supplement, Fourth Edition.
48 */
49
50/*
51 * General register state
52 */
53#define _NGREG 19
54typedef int __greg_t;
55typedef __greg_t __gregset_t[_NGREG];
56
57#define _REG_GS 0
58#define _REG_FS 1
59#define _REG_ES 2
60#define _REG_DS 3
61#define _REG_EDI 4
62#define _REG_ESI 5
63#define _REG_EBP 6
64#define _REG_ESP 7
65#define _REG_EBX 8
66#define _REG_EDX 9
67#define _REG_ECX 10
68#define _REG_EAX 11
69#define _REG_TRAPNO 12
70#define _REG_ERR 13
71#define _REG_EIP 14
72#define _REG_CS 15
73#define _REG_EFL 16
74#define _REG_UESP 17
75#define _REG_SS 18
76
77/*
78 * Floating point register state
79 */
80typedef struct {
81 union {
82 struct {
83 int __fp_state[27]; /* Environment and registers */
84 } __fpchip_state; /* x87 regs in fsave format */
85 struct {
86 char __fp_xmm[512];
87 } __fp_xmm_state; /* x87 and xmm regs in fxsave format */
88 int __fp_fpregs[128];
89 struct {
90 /*
91 * `The XSAVE feature set does not use bytes
92 * 511:416; bytes 463:416 are reserved.'
93 *
94 * We take a part out of this to form a pointer
95 * to an external XSAVE area. This way, we can
96 * replicate the FXSAVE parts for the benefit
97 * of userland programs that aren't aware of
98 * the XSAVE pointer, have used the extended
99 * CPU registers (ymmN/zmmN/&c.), and want to
100 * examine the x87/SSE register state in a
101 * signal handler. The kernel does not use
102 * this part.
103 */
104 char __fxsave[416];
105 char __rsvd[48];
106 __greg_t __xsaveptr;
107 __greg_t __xsavelen;
108 char __pad[40];
109 } __xsave;
110 } __fp_reg_set;
111 int __fp_pad[33]; /* Historic padding */
112} __fpregset_t;
113__CTASSERT(sizeof (__fpregset_t) == 512 + 33 * 4);
114
115typedef struct {
116 __gregset_t __gregs;
117 __fpregset_t __fpregs;
118 __greg_t _mc_tlsbase;
119} mcontext_t;
120
121#define _UC_FXSAVE _UC_MD_BIT5 /* FP state is in FXSAVE format in XMM space */
122
123#define _UC_MACHINE_PAD 4 /* Padding appended to ucontext_t */
124
125#define _UC_UCONTEXT_ALIGN (~0xf)
126
127#ifndef _UC_MACHINE_SP
128#define _UC_MACHINE_SP(uc) ((uc)->uc_mcontext.__gregs[_REG_UESP])
129#endif
130#define _UC_MACHINE_FP(uc) ((uc)->uc_mcontext.__gregs[_REG_EBP])
131#define _UC_MACHINE_PC(uc) ((uc)->uc_mcontext.__gregs[_REG_EIP])
132#define _UC_MACHINE_INTRV(uc) ((uc)->uc_mcontext.__gregs[_REG_EAX])
133
134#define _UC_MACHINE_SET_PC(uc, pc) _UC_MACHINE_PC(uc) = (pc)
135
136#define __UCONTEXT_SIZE 776
137
138#endif /* !_I386_MCONTEXT_H_ */