xref: /openbsd/sys/arch/arm64/include/asm.h (revision 771fbea0)
1 /*	$OpenBSD: asm.h,v 1.6 2019/05/04 16:18:35 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 #ifdef __ELF__
42 # define _C_LABEL(x)	x
43 #else
44 # ifdef __STDC__
45 #  define _C_LABEL(x)	_ ## x
46 # else
47 #  define _C_LABEL(x)	_/**/x
48 # endif
49 #endif
50 #define	_ASM_LABEL(x)	x
51 
52 #ifdef __STDC__
53 # define __CONCAT(x,y)	x ## y
54 # define __STRING(x)	#x
55 #else
56 # define __CONCAT(x,y)	x/**/y
57 # define __STRING(x)	"x"
58 #endif
59 
60 #ifndef _ALIGN_TEXT
61 # define _ALIGN_TEXT .align 0
62 #endif
63 
64 /*
65  * gas/arm uses @ as a single comment character and thus cannot be used here
66  * Instead it recognised the # instead of an @ symbols in .type directives
67  * We define a couple of macros so that assembly code will not be dependant
68  * on one or the other.
69  */
70 #define _ASM_TYPE_FUNCTION	#function
71 #define _ASM_TYPE_OBJECT	#object
72 #define _ENTRY(x) \
73 	.text; _ALIGN_TEXT; .globl x; .type x,_ASM_TYPE_FUNCTION; x:
74 
75 #if defined(PROF) || defined(GPROF)
76 #  define _PROF_PROLOGUE	\
77 	stp	x29, x30, [sp, #-16]!; \
78 	mov fp, sp;		\
79 	bl __mcount; 		\
80 	ldp	x29, x30, [sp], #16;
81 #else
82 # define _PROF_PROLOGUE
83 #endif
84 
85 #if defined(_RET_PROTECTOR)
86 # define RETGUARD_CALC_COOKIE(reg) \
87 	eor     reg, reg, x30
88 
89 # define RETGUARD_LOAD_RANDOM(x, reg) \
90 	adrp    reg, __CONCAT(__retguard_, x); \
91 	ldr     reg, [reg, :lo12:__CONCAT(__retguard_, x)]
92 
93 # define RETGUARD_SETUP(x, reg) \
94 	RETGUARD_SYMBOL(x); \
95 	RETGUARD_LOAD_RANDOM(x, reg); \
96 	RETGUARD_CALC_COOKIE(reg)
97 
98 # define RETGUARD_CHECK(x, reg) \
99 	RETGUARD_CALC_COOKIE(reg); \
100 	RETGUARD_LOAD_RANDOM(x, x9); \
101 	subs    reg, reg, x9; \
102 	cbz     reg, 66f; \
103 	brk     #0x1; \
104 66:
105 
106 # define RETGUARD_PUSH(reg) \
107 	str     reg, [sp, #-16]!
108 
109 # define RETGUARD_POP(reg) \
110 	ldr     reg, [sp, #16]!
111 
112 # define RETGUARD_SYMBOL(x) \
113 	.ifndef __CONCAT(__retguard_, x); \
114 	.hidden __CONCAT(__retguard_, x); \
115 	.type   __CONCAT(__retguard_, x),@object; \
116 	.pushsection .openbsd.randomdata.retguard,"aw",@progbits; \
117 	.weak   __CONCAT(__retguard_, x); \
118 	.p2align 3; \
119 	__CONCAT(__retguard_, x): ; \
120 	.xword 0; \
121 	.size __CONCAT(__retguard_, x), 8; \
122 	.popsection; \
123 	.endif
124 #else
125 # define RETGUARD_CALC_COOKIE(reg)
126 # define RETGUARD_LOAD_RANDOM(x, reg)
127 # define RETGUARD_SETUP(x, reg)
128 # define RETGUARD_CHECK(x, reg)
129 # define RETGUARD_PUSH(reg)
130 # define RETGUARD_POP(reg)
131 # define RETGUARD_SYMBOL(x)
132 #endif
133 
134 #define	ENTRY(y)	_ENTRY(_C_LABEL(y)); _PROF_PROLOGUE
135 #define	ENTRY_NP(y)	_ENTRY(_C_LABEL(y))
136 #define	ASENTRY(y)	_ENTRY(_ASM_LABEL(y)); _PROF_PROLOGUE
137 #define	ASENTRY_NP(y)	_ENTRY(_ASM_LABEL(y))
138 #define	END(y)		.size y, . - y
139 #define EENTRY(sym)	 .globl  sym; sym:
140 #define EEND(sym)
141 
142 #if defined(__ELF__) && defined(__PIC__)
143 #ifdef __STDC__
144 #define	PIC_SYM(x,y)	x ## ( ## y ## )
145 #else
146 #define	PIC_SYM(x,y)	x/**/(/**/y/**/)
147 #endif
148 #else
149 #define	PIC_SYM(x,y)	x
150 #endif
151 
152 #ifdef __ELF__
153 #define	STRONG_ALIAS(alias,sym)						\
154 	.global alias;							\
155 	alias = sym
156 #define	WEAK_ALIAS(alias,sym)						\
157 	.weak alias;							\
158 	alias = sym
159 #endif
160 
161 #ifdef __STDC__
162 #define	WARN_REFERENCES(sym,msg)					\
163 	.stabs msg ## ,30,0,0,0 ;					\
164 	.stabs __STRING(_C_LABEL(sym)) ## ,1,0,0,0
165 #elif defined(__ELF__)
166 #define	WARN_REFERENCES(sym,msg)					\
167 	.stabs msg,30,0,0,0 ;						\
168 	.stabs __STRING(sym),1,0,0,0
169 #else
170 #define	WARN_REFERENCES(sym,msg)					\
171 	.stabs msg,30,0,0,0 ;						\
172 	.stabs __STRING(_/**/sym),1,0,0,0
173 #endif /* __STDC__ */
174 
175 #endif /* !_MACHINE_ASM_H_ */
176