1 /* Copyright (C) 2005-2021 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/sysv/linux/generic/sysdep.h> 25 26 /* Defines RTLD_PRIVATE_ERRNO and USE_DL_SYSINFO. */ 27 #include <dl-sysdep.h> 28 29 #include <tls.h> 30 31 /* In order to get __set_errno() definition in INLINE_SYSCALL. */ 32 #ifndef __ASSEMBLER__ 33 #include <errno.h> 34 #endif 35 36 /* For Linux we can use the system call table in the header file 37 /usr/include/asm/unistd.h 38 of the kernel. But these symbols do not follow the SYS_* syntax 39 so we have to redefine the `SYS_ify' macro here. */ 40 #undef SYS_ify 41 #define SYS_ify(syscall_name) (__NR_##syscall_name) 42 43 #ifdef __ASSEMBLER__ 44 45 /* Linux uses a negative return value to indicate syscall errors, 46 unlike most Unices, which use the condition codes' carry flag. 47 48 Since version 2.1 the return value of a system call might be 49 negative even if the call succeeded. E.g., the `lseek' system call 50 might return a large offset. Therefore we must not anymore test 51 for < 0, but test for a real error by making sure the value in R0 52 is a real error number. Linus said he will make sure the no syscall 53 returns a value in -1 .. -4095 as a valid result so we can safely 54 test with -4095. */ 55 56 # undef PSEUDO 57 # define PSEUDO(name, syscall_name, args) \ 58 .text; \ 59 ENTRY (name); \ 60 DO_CALL (syscall_name, args); \ 61 cmn x0, #4095; \ 62 b.cs .Lsyscall_error; 63 64 # undef PSEUDO_END 65 # define PSEUDO_END(name) \ 66 SYSCALL_ERROR_HANDLER \ 67 END (name) 68 69 # undef PSEUDO_NOERRNO 70 # define PSEUDO_NOERRNO(name, syscall_name, args) \ 71 .text; \ 72 ENTRY (name); \ 73 DO_CALL (syscall_name, args); 74 75 # undef PSEUDO_END_NOERRNO 76 # define PSEUDO_END_NOERRNO(name) \ 77 END (name) 78 79 # define ret_NOERRNO ret 80 81 /* The function has to return the error code. */ 82 # undef PSEUDO_ERRVAL 83 # define PSEUDO_ERRVAL(name, syscall_name, args) \ 84 .text; \ 85 ENTRY (name) \ 86 DO_CALL (syscall_name, args); \ 87 neg x0, x0 88 89 # undef PSEUDO_END_ERRVAL 90 # define PSEUDO_END_ERRVAL(name) \ 91 END (name) 92 93 # define ret_ERRVAL ret 94 95 # if !IS_IN (libc) 96 # define SYSCALL_ERROR .Lsyscall_error 97 # if RTLD_PRIVATE_ERRNO 98 # define SYSCALL_ERROR_HANDLER \ 99 .Lsyscall_error: \ 100 adrp x1, C_SYMBOL_NAME(rtld_errno); \ 101 neg w0, w0; \ 102 str w0, [x1, :lo12:C_SYMBOL_NAME(rtld_errno)]; \ 103 mov x0, -1; \ 104 RET; 105 # else 106 107 # define SYSCALL_ERROR_HANDLER \ 108 .Lsyscall_error: \ 109 adrp x1, :gottprel:errno; \ 110 neg w2, w0; \ 111 ldr PTR_REG(1), [x1, :gottprel_lo12:errno]; \ 112 mrs x3, tpidr_el0; \ 113 mov x0, -1; \ 114 str w2, [x1, x3]; \ 115 RET; 116 # endif 117 # else 118 # define SYSCALL_ERROR __syscall_error 119 # define SYSCALL_ERROR_HANDLER \ 120 .Lsyscall_error: \ 121 b __syscall_error; 122 # endif 123 124 /* Linux takes system call args in registers: 125 syscall number x8 126 arg 1 x0 127 arg 2 x1 128 arg 3 x2 129 arg 4 x3 130 arg 5 x4 131 arg 6 x5 132 arg 7 x6 133 134 The compiler is going to form a call by coming here, through PSEUDO, with 135 arguments 136 syscall number in the DO_CALL macro 137 arg 1 x0 138 arg 2 x1 139 arg 3 x2 140 arg 4 x3 141 arg 5 x4 142 arg 6 x5 143 arg 7 x6 144 145 */ 146 147 # undef DO_CALL 148 # define DO_CALL(syscall_name, args) \ 149 mov x8, SYS_ify (syscall_name); \ 150 svc 0 151 152 #else /* not __ASSEMBLER__ */ 153 154 # ifdef __LP64__ 155 # define VDSO_NAME "LINUX_2.6.39" 156 # define VDSO_HASH 123718537 157 # else 158 # define VDSO_NAME "LINUX_4.9" 159 # define VDSO_HASH 61765625 160 # endif 161 162 /* List of system calls which are supported as vsyscalls. */ 163 # define HAVE_CLOCK_GETRES64_VSYSCALL "__kernel_clock_getres" 164 # define HAVE_CLOCK_GETTIME64_VSYSCALL "__kernel_clock_gettime" 165 # define HAVE_GETTIMEOFDAY_VSYSCALL "__kernel_gettimeofday" 166 167 # define SINGLE_THREAD_BY_GLOBAL 1 168 169 # undef INTERNAL_SYSCALL_RAW 170 # define INTERNAL_SYSCALL_RAW(name, nr, args...) \ 171 ({ long _sys_result; \ 172 { \ 173 LOAD_ARGS_##nr (args) \ 174 register long _x8 asm ("x8") = (name); \ 175 asm volatile ("svc 0 // syscall " # name \ 176 : "=r" (_x0) : "r"(_x8) ASM_ARGS_##nr : "memory"); \ 177 _sys_result = _x0; \ 178 } \ 179 _sys_result; }) 180 181 # undef INTERNAL_SYSCALL 182 # define INTERNAL_SYSCALL(name, nr, args...) \ 183 INTERNAL_SYSCALL_RAW(SYS_ify(name), nr, args) 184 185 # undef INTERNAL_SYSCALL_AARCH64 186 # define INTERNAL_SYSCALL_AARCH64(name, nr, args...) \ 187 INTERNAL_SYSCALL_RAW(__ARM_NR_##name, nr, args) 188 189 # define LOAD_ARGS_0() \ 190 register long _x0 asm ("x0"); 191 # define LOAD_ARGS_1(x0) \ 192 long _x0tmp = (long) (x0); \ 193 LOAD_ARGS_0 () \ 194 _x0 = _x0tmp; 195 # define LOAD_ARGS_2(x0, x1) \ 196 long _x1tmp = (long) (x1); \ 197 LOAD_ARGS_1 (x0) \ 198 register long _x1 asm ("x1") = _x1tmp; 199 # define LOAD_ARGS_3(x0, x1, x2) \ 200 long _x2tmp = (long) (x2); \ 201 LOAD_ARGS_2 (x0, x1) \ 202 register long _x2 asm ("x2") = _x2tmp; 203 # define LOAD_ARGS_4(x0, x1, x2, x3) \ 204 long _x3tmp = (long) (x3); \ 205 LOAD_ARGS_3 (x0, x1, x2) \ 206 register long _x3 asm ("x3") = _x3tmp; 207 # define LOAD_ARGS_5(x0, x1, x2, x3, x4) \ 208 long _x4tmp = (long) (x4); \ 209 LOAD_ARGS_4 (x0, x1, x2, x3) \ 210 register long _x4 asm ("x4") = _x4tmp; 211 # define LOAD_ARGS_6(x0, x1, x2, x3, x4, x5) \ 212 long _x5tmp = (long) (x5); \ 213 LOAD_ARGS_5 (x0, x1, x2, x3, x4) \ 214 register long _x5 asm ("x5") = _x5tmp; 215 # define LOAD_ARGS_7(x0, x1, x2, x3, x4, x5, x6)\ 216 long _x6tmp = (long) (x6); \ 217 LOAD_ARGS_6 (x0, x1, x2, x3, x4, x5) \ 218 register long _x6 asm ("x6") = _x6tmp; 219 220 # define ASM_ARGS_0 221 # define ASM_ARGS_1 , "r" (_x0) 222 # define ASM_ARGS_2 ASM_ARGS_1, "r" (_x1) 223 # define ASM_ARGS_3 ASM_ARGS_2, "r" (_x2) 224 # define ASM_ARGS_4 ASM_ARGS_3, "r" (_x3) 225 # define ASM_ARGS_5 ASM_ARGS_4, "r" (_x4) 226 # define ASM_ARGS_6 ASM_ARGS_5, "r" (_x5) 227 # define ASM_ARGS_7 ASM_ARGS_6, "r" (_x6) 228 229 # undef INTERNAL_SYSCALL_NCS 230 # define INTERNAL_SYSCALL_NCS(number, nr, args...) \ 231 INTERNAL_SYSCALL_RAW (number, nr, args) 232 233 #undef HAVE_INTERNAL_BRK_ADDR_SYMBOL 234 #define HAVE_INTERNAL_BRK_ADDR_SYMBOL 1 235 236 #endif /* __ASSEMBLER__ */ 237 238 /* Pointer mangling is supported for AArch64. */ 239 #if (IS_IN (rtld) \ 240 || (!defined SHARED && (IS_IN (libc) \ 241 || IS_IN (libpthread)))) 242 # ifdef __ASSEMBLER__ 243 /* Note, dst, src, guard, and tmp are all register numbers rather than 244 register names so they will work with both ILP32 and LP64. */ 245 # define PTR_MANGLE(dst, src, guard, tmp) \ 246 LDST_PCREL (ldr, guard, tmp, C_SYMBOL_NAME(__pointer_chk_guard_local)); \ 247 PTR_MANGLE2 (dst, src, guard) 248 /* Use PTR_MANGLE2 for efficiency if guard is already loaded. */ 249 # define PTR_MANGLE2(dst, src, guard)\ 250 eor x##dst, x##src, x##guard 251 # define PTR_DEMANGLE(dst, src, guard, tmp)\ 252 PTR_MANGLE (dst, src, guard, tmp) 253 # define PTR_DEMANGLE2(dst, src, guard)\ 254 PTR_MANGLE2 (dst, src, guard) 255 # else 256 extern uintptr_t __pointer_chk_guard_local attribute_relro attribute_hidden; 257 # define PTR_MANGLE(var) \ 258 (var) = (__typeof (var)) ((uintptr_t) (var) ^ __pointer_chk_guard_local) 259 # define PTR_DEMANGLE(var) PTR_MANGLE (var) 260 # endif 261 #else 262 # ifdef __ASSEMBLER__ 263 /* Note, dst, src, guard, and tmp are all register numbers rather than 264 register names so they will work with both ILP32 and LP64. */ 265 # define PTR_MANGLE(dst, src, guard, tmp) \ 266 LDST_GLOBAL (ldr, guard, tmp, C_SYMBOL_NAME(__pointer_chk_guard)); \ 267 PTR_MANGLE2 (dst, src, guard) 268 /* Use PTR_MANGLE2 for efficiency if guard is already loaded. */ 269 # define PTR_MANGLE2(dst, src, guard)\ 270 eor x##dst, x##src, x##guard 271 # define PTR_DEMANGLE(dst, src, guard, tmp)\ 272 PTR_MANGLE (dst, src, guard, tmp) 273 # define PTR_DEMANGLE2(dst, src, guard)\ 274 PTR_MANGLE2 (dst, src, guard) 275 # else 276 extern uintptr_t __pointer_chk_guard attribute_relro; 277 # define PTR_MANGLE(var) \ 278 (var) = (__typeof (var)) ((uintptr_t) (var) ^ __pointer_chk_guard) 279 # define PTR_DEMANGLE(var) PTR_MANGLE (var) 280 # endif 281 #endif 282 283 #endif /* linux/aarch64/sysdep.h */ 284