1/* $OpenBSD: asm.h,v 1.12 2023/03/27 19:02:48 kettenis Exp $ */
2/* $NetBSD: asm.h,v 1.4 2001/07/16 05:43:32 matt Exp $ */
3
4/*
5 * Copyright (c) 1990 The Regents of the University of California.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * William Jolitz.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * from: @(#)asm.h 5.5 (Berkeley) 5/7/91
36 */
37
38#ifndef _MACHINE_ASM_H_
39#define _MACHINE_ASM_H_
40
41#define _C_LABEL(x) x
42#define _ASM_LABEL(x) x
43
44#ifdef __STDC__
45# define __CONCAT(x,y) x ## y
46# define __STRING(x) #x
47#else
48# define __CONCAT(x,y) x/**/y
49# define __STRING(x) "x"
50#endif
51
52#ifndef _ALIGN_TEXT
53# define _ALIGN_TEXT .align 0
54#endif
55
56/*
57 * gas/arm uses @ as a single comment character and thus cannot be used here
58 * Instead it recognised the # instead of an @ symbols in .type directives
59 * We define a couple of macros so that assembly code will not be dependant
60 * on one or the other.
61 */
62#define _ASM_TYPE_FUNCTION #function
63#define _ASM_TYPE_OBJECT #object
64/* NB == No Binding: use .globl or .weak as necessary */
65#define _ENTRY_NB(x) \
66 .text; _ALIGN_TEXT; .type x,_ASM_TYPE_FUNCTION; x:
67#define _ENTRY(x) .globl x; _ENTRY_NB(x)
68
69#if defined(PROF) || defined(GPROF)
70# define _PROF_PROLOGUE \
71 stp x29, x30, [sp, #-16]!; \
72 mov fp, sp; \
73 bl __mcount; \
74 ldp x29, x30, [sp], #16;
75#else
76# define _PROF_PROLOGUE
77#endif
78
79#if defined(_RET_PROTECTOR)
80# define RETGUARD_CALC_COOKIE(reg) \
81 eor reg, reg, x30
82
83# define RETGUARD_LOAD_RANDOM(x, reg) \
84 adrp reg, __CONCAT(__retguard_, x); \
85 ldr reg, [reg, :lo12:__CONCAT(__retguard_, x)]
86
87# define RETGUARD_SETUP(x, reg) \
88 RETGUARD_SYMBOL(x); \
89 RETGUARD_LOAD_RANDOM(x, reg); \
90 RETGUARD_CALC_COOKIE(reg)
91
92# define RETGUARD_CHECK(x, reg) \
93 RETGUARD_CALC_COOKIE(reg); \
94 RETGUARD_LOAD_RANDOM(x, x9); \
95 subs reg, reg, x9; \
96 cbz reg, 66f; \
97 brk #0x1; \
9866:
99
100# define RETGUARD_PUSH(reg) \
101 str reg, [sp, #-16]!
102
103# define RETGUARD_POP(reg) \
104 ldr reg, [sp, #16]!
105
106# define RETGUARD_SYMBOL(x) \
107 .ifndef __CONCAT(__retguard_, x); \
108 .hidden __CONCAT(__retguard_, x); \
109 .type __CONCAT(__retguard_, x),@object; \
110 .pushsection .openbsd.randomdata.retguard,"aw",@progbits; \
111 .weak __CONCAT(__retguard_, x); \
112 .p2align 3; \
113 __CONCAT(__retguard_, x): ; \
114 .xword 0; \
115 .size __CONCAT(__retguard_, x), 8; \
116 .popsection; \
117 .endif
118#else
119# define RETGUARD_CALC_COOKIE(reg)
120# define RETGUARD_LOAD_RANDOM(x, reg)
121# define RETGUARD_SETUP(x, reg)
122# define RETGUARD_CHECK(x, reg)
123# define RETGUARD_PUSH(reg)
124# define RETGUARD_POP(reg)
125# define RETGUARD_SYMBOL(x)
126#endif
127
128#define ENTRY(y) _ENTRY(y); bti c; _PROF_PROLOGUE
129#define ENTRY_NP(y) _ENTRY(y); bti c
130#define ENTRY_NB(y) _ENTRY_NB(y); bti c; _PROF_PROLOGUE
131#define ASENTRY(y) _ENTRY(y); bti c; _PROF_PROLOGUE
132#define ASENTRY_NP(y) _ENTRY(y); bti c
133#define END(y) .size y, . - y
134#define EENTRY(sym) .globl sym; sym:
135#define EEND(sym)
136
137#ifdef __PIC__
138#define PIC_SYM(x,y) x(y)
139#else
140#define PIC_SYM(x,y) x
141#endif
142
143#define STRONG_ALIAS(alias,sym) \
144 .global alias; \
145 alias = sym
146#define WEAK_ALIAS(alias,sym) \
147 .weak alias; \
148 alias = sym
149
150#endif /* !_MACHINE_ASM_H_ */