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      1 /*	$NetBSD: mcontext.h,v 1.20 2026/07/10 15:11:25 riastradh 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
     54 typedef	int		__greg_t;
     55 typedef	__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  */
     80 typedef 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 
    115 typedef 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_ */
    139