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1/* Copyright (C) 2005-2025 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 _LINUX_AARCH64_SYSDEP_H
20#define _LINUX_AARCH64_SYSDEP_H 1
21
22#include <sysdeps/unix/sysdep.h>
23#include <sysdeps/aarch64/sysdep.h>
24#include <sysdeps/unix/sysdep.h>
25#include <sysdeps/unix/sysv/linux/sysdep.h>
26
27/* Defines RTLD_PRIVATE_ERRNO and USE_DL_SYSINFO. */
28#include <dl-sysdep.h>
29
30#include <tls.h>
31
32/* In order to get __set_errno() definition in INLINE_SYSCALL. */
33#ifndef __ASSEMBLER__
34#include <errno.h>
35#endif
36
37/* For Linux we can use the system call table in the header file
38 /usr/include/asm/unistd.h
39 of the kernel. But these symbols do not follow the SYS_* syntax
40 so we have to redefine the `SYS_ify' macro here. */
41#undef SYS_ify
42#define SYS_ify(syscall_name) (__NR_##syscall_name)
43
44#ifdef __ASSEMBLER__
45
46/* Linux uses a negative return value to indicate syscall errors,
47 unlike most Unices, which use the condition codes' carry flag.
48
49 Since version 2.1 the return value of a system call might be
50 negative even if the call succeeded. E.g., the `lseek' system call
51 might return a large offset. Therefore we must not anymore test
52 for < 0, but test for a real error by making sure the value in R0
53 is a real error number. Linus said he will make sure the no syscall
54 returns a value in -1 .. -4095 as a valid result so we can safely
55 test with -4095. */
56
57# undef PSEUDO
58# define PSEUDO(name, syscall_name, args) \
59 .text; \
60 ENTRY (name); \
61 DO_CALL (syscall_name, args); \
62 cmn x0, #4095; \
63 b.cs .Lsyscall_error;
64
65# undef PSEUDO_END
66# define PSEUDO_END(name) \
67 SYSCALL_ERROR_HANDLER \
68 END (name)
69
70# undef PSEUDO_NOERRNO
71# define PSEUDO_NOERRNO(name, syscall_name, args) \
72 .text; \
73 ENTRY (name); \
74 DO_CALL (syscall_name, args);
75
76# undef PSEUDO_END_NOERRNO
77# define PSEUDO_END_NOERRNO(name) \
78 END (name)
79
80# define ret_NOERRNO ret
81
82/* The function has to return the error code. */
83# undef PSEUDO_ERRVAL
84# define PSEUDO_ERRVAL(name, syscall_name, args) \
85 .text; \
86 ENTRY (name) \
87 DO_CALL (syscall_name, args); \
88 neg x0, x0
89
90# undef PSEUDO_END_ERRVAL
91# define PSEUDO_END_ERRVAL(name) \
92 END (name)
93
94# define ret_ERRVAL ret
95
96# if !IS_IN (libc)
97# define SYSCALL_ERROR .Lsyscall_error
98# if RTLD_PRIVATE_ERRNO
99# define SYSCALL_ERROR_HANDLER \
100.Lsyscall_error: \
101 adrp x1, C_SYMBOL_NAME(rtld_errno); \
102 neg w0, w0; \
103 str w0, [x1, :lo12:C_SYMBOL_NAME(rtld_errno)]; \
104 mov x0, -1; \
105 RET;
106# else
107
108# define SYSCALL_ERROR_HANDLER \
109.Lsyscall_error: \
110 adrp x1, :gottprel:errno; \
111 neg w2, w0; \
112 ldr PTR_REG(1), [x1, :gottprel_lo12:errno]; \
113 mrs x3, tpidr_el0; \
114 mov x0, -1; \
115 str w2, [x1, x3]; \
116 RET;
117# endif
118# else
119# define SYSCALL_ERROR __syscall_error
120# define SYSCALL_ERROR_HANDLER \
121.Lsyscall_error: \
122 b __syscall_error;
123# endif
124
125/* Linux takes system call args in registers:
126 syscall number x8
127 arg 1 x0
128 arg 2 x1
129 arg 3 x2
130 arg 4 x3
131 arg 5 x4
132 arg 6 x5
133 arg 7 x6
134
135 The compiler is going to form a call by coming here, through PSEUDO, with
136 arguments
137 syscall number in the DO_CALL macro
138 arg 1 x0
139 arg 2 x1
140 arg 3 x2
141 arg 4 x3
142 arg 5 x4
143 arg 6 x5
144 arg 7 x6
145
146*/
147
148# undef DO_CALL
149# define DO_CALL(syscall_name, args) \
150 mov x8, SYS_ify (syscall_name); \
151 svc 0
152
153#else /* not __ASSEMBLER__ */
154
155# define VDSO_NAME "LINUX_2.6.39"
156# define VDSO_HASH 123718537
157
158/* List of system calls which are supported as vsyscalls. */
159# define HAVE_CLOCK_GETRES64_VSYSCALL "__kernel_clock_getres"
160# define HAVE_CLOCK_GETTIME64_VSYSCALL "__kernel_clock_gettime"
161# define HAVE_GETTIMEOFDAY_VSYSCALL "__kernel_gettimeofday"
162# define HAVE_GETRANDOM_VSYSCALL "__kernel_getrandom"
163
164# define HAVE_CLONE3_WRAPPER 1
165
166# undef INTERNAL_SYSCALL_RAW
167# define INTERNAL_SYSCALL_RAW(name, nr, args...) \
168 ({ long _sys_result; \
169 { \
170 LOAD_ARGS_##nr (args) \
171 register long _x8 asm ("x8") = (name); \
172 asm volatile ("svc 0 // syscall " # name \
173 : "=r" (_x0) : "r"(_x8) ASM_ARGS_##nr : "memory"); \
174 _sys_result = _x0; \
175 } \
176 _sys_result; })
177
178# undef INTERNAL_SYSCALL
179# define INTERNAL_SYSCALL(name, nr, args...) \
180 INTERNAL_SYSCALL_RAW(SYS_ify(name), nr, args)
181
182# undef INTERNAL_SYSCALL_AARCH64
183# define INTERNAL_SYSCALL_AARCH64(name, nr, args...) \
184 INTERNAL_SYSCALL_RAW(__ARM_NR_##name, nr, args)
185
186# define LOAD_ARGS_0() \
187 register long _x0 asm ("x0");
188# define LOAD_ARGS_1(x0) \
189 long _x0tmp = (long) (x0); \
190 LOAD_ARGS_0 () \
191 _x0 = _x0tmp;
192# define LOAD_ARGS_2(x0, x1) \
193 long _x1tmp = (long) (x1); \
194 LOAD_ARGS_1 (x0) \
195 register long _x1 asm ("x1") = _x1tmp;
196# define LOAD_ARGS_3(x0, x1, x2) \
197 long _x2tmp = (long) (x2); \
198 LOAD_ARGS_2 (x0, x1) \
199 register long _x2 asm ("x2") = _x2tmp;
200# define LOAD_ARGS_4(x0, x1, x2, x3) \
201 long _x3tmp = (long) (x3); \
202 LOAD_ARGS_3 (x0, x1, x2) \
203 register long _x3 asm ("x3") = _x3tmp;
204# define LOAD_ARGS_5(x0, x1, x2, x3, x4) \
205 long _x4tmp = (long) (x4); \
206 LOAD_ARGS_4 (x0, x1, x2, x3) \
207 register long _x4 asm ("x4") = _x4tmp;
208# define LOAD_ARGS_6(x0, x1, x2, x3, x4, x5) \
209 long _x5tmp = (long) (x5); \
210 LOAD_ARGS_5 (x0, x1, x2, x3, x4) \
211 register long _x5 asm ("x5") = _x5tmp;
212# define LOAD_ARGS_7(x0, x1, x2, x3, x4, x5, x6)\
213 long _x6tmp = (long) (x6); \
214 LOAD_ARGS_6 (x0, x1, x2, x3, x4, x5) \
215 register long _x6 asm ("x6") = _x6tmp;
216
217# define ASM_ARGS_0
218# define ASM_ARGS_1 , "r" (_x0)
219# define ASM_ARGS_2 ASM_ARGS_1, "r" (_x1)
220# define ASM_ARGS_3 ASM_ARGS_2, "r" (_x2)
221# define ASM_ARGS_4 ASM_ARGS_3, "r" (_x3)
222# define ASM_ARGS_5 ASM_ARGS_4, "r" (_x4)
223# define ASM_ARGS_6 ASM_ARGS_5, "r" (_x5)
224# define ASM_ARGS_7 ASM_ARGS_6, "r" (_x6)
225
226# undef INTERNAL_SYSCALL_NCS
227# define INTERNAL_SYSCALL_NCS(number, nr, args...) \
228 INTERNAL_SYSCALL_RAW (number, nr, args)
229
230#undef HAVE_INTERNAL_BRK_ADDR_SYMBOL
231#define HAVE_INTERNAL_BRK_ADDR_SYMBOL 1
232
233#endif /* __ASSEMBLER__ */
234
235#endif /* linux/aarch64/sysdep.h */