1/* Copyright (C) 1997-2026 Free Software Foundation, Inc.
2
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 2.1 of the
8 License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#ifndef _AARCH64_SYSDEP_H
20#define _AARCH64_SYSDEP_H
21
22#include <sysdeps/generic/sysdep.h>
23
24#ifdef __ASSEMBLER__
25
26/* CFI directive for return address. */
27#define cfi_negate_ra_state .cfi_negate_ra_state
28
29/* Syntactic details of assembler. */
30
31#define ASM_SIZE_DIRECTIVE(name) .size name,.-name
32
33/* Guarded Control Stack support. */
34#define CHKFEAT_X16 hint 40
35#define MRS_GCSPR(x) mrs x, s3_3_c2_c5_1
36#define GCSPOPM(x) sysl x, #3, c7, c7, #1
37#define GCSSS1(x) sys #3, c7, c7, #2, x
38#define GCSSS2(x) sysl x, #3, c7, c7, #3
39
40/* GNU_PROPERTY_AARCH64_* macros from elf.h for use in asm code. */
41#define FEATURE_1_AND 0xc0000000
42#define FEATURE_1_BTI 1
43#define FEATURE_1_PAC 2
44#define FEATURE_1_GCS 4
45
46#define GNU_PROPERTY(type, value) \
47 .section .note.gnu.property, "a"; \
48 .p2align 3; \
49 .word 4; \
50 .word 16; \
51 .word 5; \
52 .asciz "GNU"; \
53 .word type; \
54 .word 4; \
55 .word value; \
56 .word 0; \
57 .text
58
59#ifdef __ARM_BUILDATTR64_FV
60/* Add AArch64 feature bits build attributes. */
61# define FEATURE_1_AND_MARK(value) \
62 .aeabi_subsection aeabi_feature_and_bits, optional, ULEB128; \
63 .if ((value) & FEATURE_1_BTI); \
64 .aeabi_attribute Tag_Feature_BTI, 1; \
65 .else; \
66 .aeabi_attribute Tag_Feature_BTI, 0; \
67 .endif; \
68 .if ((value) & FEATURE_1_GCS); \
69 .aeabi_attribute Tag_Feature_GCS, 1; \
70 .else; \
71 .aeabi_attribute Tag_Feature_GCS, 0; \
72 .endif; \
73 .if ((value) & FEATURE_1_PAC); \
74 .aeabi_attribute Tag_Feature_PAC, 1; \
75 .else; \
76 .aeabi_attribute Tag_Feature_PAC, 0; \
77 .endif; \
78 .text
79#else
80/* Add a NT_GNU_PROPERTY_TYPE_0 note. */
81# define FEATURE_1_AND_MARK(value) GNU_PROPERTY (FEATURE_1_AND, value)
82#endif /* __ARM_BUILDATTR64_FV */
83
84/* Add marking with the supported features to all asm code where sysdep.h
85 is included. */
86FEATURE_1_AND_MARK (FEATURE_1_BTI | FEATURE_1_PAC | FEATURE_1_GCS)
87
88/* Define an entry point visible from C. */
89#define ENTRY(name) \
90 .globl C_SYMBOL_NAME(name); \
91 .type C_SYMBOL_NAME(name),%function; \
92 .p2align 6; \
93 C_LABEL(name) \
94 cfi_startproc; \
95 bti c; \
96 CALL_MCOUNT
97
98/* Define an entry point visible from C. */
99#define ENTRY_ALIGN(name, align) \
100 .globl C_SYMBOL_NAME(name); \
101 .type C_SYMBOL_NAME(name),%function; \
102 .p2align align; \
103 C_LABEL(name) \
104 cfi_startproc; \
105 bti c; \
106 CALL_MCOUNT
107
108/* Define an entry point visible from C with a specified alignment and
109 pre-padding with NOPs. This can be used to ensure that a critical
110 loop within a function is cache line aligned. Note this version
111 does not adjust the padding if CALL_MCOUNT is defined. */
112
113#define ENTRY_ALIGN_AND_PAD(name, align, padding) \
114 .globl C_SYMBOL_NAME(name); \
115 .type C_SYMBOL_NAME(name),%function; \
116 .p2align align; \
117 .rep padding - 1; /* -1 for bti c. */ \
118 nop; \
119 .endr; \
120 C_LABEL(name) \
121 cfi_startproc; \
122 bti c; \
123 CALL_MCOUNT
124
125#undef END
126#define END(name) \
127 cfi_endproc; \
128 ASM_SIZE_DIRECTIVE(name)
129
130/* If compiled for profiling, call `mcount' at the start of each function. */
131#ifdef PROF
132# define CALL_MCOUNT \
133 str x30, [sp, #-80]!; \
134 cfi_adjust_cfa_offset (80); \
135 cfi_rel_offset (x30, 0); \
136 stp x0, x1, [sp, #16]; \
137 cfi_rel_offset (x0, 16); \
138 cfi_rel_offset (x1, 24); \
139 stp x2, x3, [sp, #32]; \
140 cfi_rel_offset (x2, 32); \
141 cfi_rel_offset (x3, 40); \
142 stp x4, x5, [sp, #48]; \
143 cfi_rel_offset (x4, 48); \
144 cfi_rel_offset (x5, 56); \
145 stp x6, x7, [sp, #64]; \
146 cfi_rel_offset (x6, 64); \
147 cfi_rel_offset (x7, 72); \
148 mov x0, x30; \
149 bl mcount; \
150 ldp x0, x1, [sp, #16]; \
151 cfi_restore (x0); \
152 cfi_restore (x1); \
153 ldp x2, x3, [sp, #32]; \
154 cfi_restore (x2); \
155 cfi_restore (x3); \
156 ldp x4, x5, [sp, #48]; \
157 cfi_restore (x4); \
158 cfi_restore (x5); \
159 ldp x6, x7, [sp, #64]; \
160 cfi_restore (x6); \
161 cfi_restore (x7); \
162 ldr x30, [sp], #80; \
163 cfi_adjust_cfa_offset (-80); \
164 cfi_restore (x30);
165#else
166# define CALL_MCOUNT /* Do nothing. */
167#endif
168
169/* Local label name for asm code. */
170#ifndef L
171# define L(name) .L##name
172#endif
173
174/* Since C identifiers are not normally prefixed with an underscore
175 on this system, the asm identifier `syscall_error' intrudes on the
176 C name space. Make sure we use an innocuous name. */
177#define syscall_error __syscall_error
178#define mcount _mcount
179
180#endif /* __ASSEMBLER__ */
181
182#endif /* _AARCH64_SYSDEP_H */