1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_LINKAGE_H 3 #define _LINUX_LINKAGE_H 4 5 #include <linux/compiler_types.h> 6 #include <linux/stringify.h> 7 #include <linux/export.h> 8 #include <asm/linkage.h> 9 10 /* Some toolchains use other characters (e.g. '`') to mark new line in macro */ 11 #ifndef ASM_NL 12 #define ASM_NL ; 13 #endif 14 15 #ifdef __cplusplus 16 #define CPP_ASMLINKAGE extern "C" 17 #else 18 #define CPP_ASMLINKAGE 19 #endif 20 21 #ifndef asmlinkage 22 #define asmlinkage CPP_ASMLINKAGE 23 #endif 24 25 #ifndef cond_syscall 26 #define cond_syscall(x) asm( \ 27 ".weak " __stringify(x) "\n\t" \ 28 ".set " __stringify(x) "," \ 29 __stringify(sys_ni_syscall)) 30 #endif 31 32 #ifndef SYSCALL_ALIAS 33 #define SYSCALL_ALIAS(alias, name) asm( \ 34 ".globl " __stringify(alias) "\n\t" \ 35 ".set " __stringify(alias) "," \ 36 __stringify(name)) 37 #endif 38 39 #define __page_aligned_data __section(".data..page_aligned") __aligned(PAGE_SIZE) 40 #define __page_aligned_bss __section(".bss..page_aligned") __aligned(PAGE_SIZE) 41 42 /* 43 * For assembly routines. 44 * 45 * Note when using these that you must specify the appropriate 46 * alignment directives yourself 47 */ 48 #define __PAGE_ALIGNED_DATA .section ".data..page_aligned", "aw" 49 #define __PAGE_ALIGNED_BSS .section ".bss..page_aligned", "aw" 50 51 /* 52 * This is used by architectures to keep arguments on the stack 53 * untouched by the compiler by keeping them live until the end. 54 * The argument stack may be owned by the assembly-language 55 * caller, not the callee, and gcc doesn't always understand 56 * that. 57 * 58 * We have the return value, and a maximum of six arguments. 59 * 60 * This should always be followed by a "return ret" for the 61 * protection to work (ie no more work that the compiler might 62 * end up needing stack temporaries for). 63 */ 64 /* Assembly files may be compiled with -traditional .. */ 65 #ifndef __ASSEMBLY__ 66 #ifndef asmlinkage_protect 67 # define asmlinkage_protect(n, ret, args...) do { } while (0) 68 #endif 69 #endif 70 71 #ifndef __ALIGN 72 #define __ALIGN .balign CONFIG_FUNCTION_ALIGNMENT 73 #define __ALIGN_STR __stringify(__ALIGN) 74 #endif 75 76 #ifdef __ASSEMBLY__ 77 78 /* SYM_T_FUNC -- type used by assembler to mark functions */ 79 #ifndef SYM_T_FUNC 80 #define SYM_T_FUNC STT_FUNC 81 #endif 82 83 /* SYM_T_OBJECT -- type used by assembler to mark data */ 84 #ifndef SYM_T_OBJECT 85 #define SYM_T_OBJECT STT_OBJECT 86 #endif 87 88 /* SYM_T_NONE -- type used by assembler to mark entries of unknown type */ 89 #ifndef SYM_T_NONE 90 #define SYM_T_NONE STT_NOTYPE 91 #endif 92 93 /* SYM_A_* -- align the symbol? */ 94 #define SYM_A_ALIGN ALIGN 95 #define SYM_A_NONE /* nothing */ 96 97 /* SYM_L_* -- linkage of symbols */ 98 #define SYM_L_GLOBAL(name) .globl name 99 #define SYM_L_WEAK(name) .weak name 100 #define SYM_L_LOCAL(name) /* nothing */ 101 102 #ifndef LINKER_SCRIPT 103 #define ALIGN __ALIGN 104 #define ALIGN_STR __ALIGN_STR 105 106 /* === DEPRECATED annotations === */ 107 108 #ifndef CONFIG_ARCH_USE_SYM_ANNOTATIONS 109 #ifndef GLOBAL 110 /* deprecated, use SYM_DATA*, SYM_ENTRY, or similar */ 111 #define GLOBAL(name) \ 112 .globl name ASM_NL \ 113 name: 114 #endif 115 116 #ifndef ENTRY 117 /* deprecated, use SYM_FUNC_START */ 118 #define ENTRY(name) \ 119 SYM_FUNC_START(name) 120 #endif 121 #endif /* CONFIG_ARCH_USE_SYM_ANNOTATIONS */ 122 #endif /* LINKER_SCRIPT */ 123 124 #ifndef CONFIG_ARCH_USE_SYM_ANNOTATIONS 125 #ifndef WEAK 126 /* deprecated, use SYM_FUNC_START_WEAK* */ 127 #define WEAK(name) \ 128 SYM_FUNC_START_WEAK(name) 129 #endif 130 131 #ifndef END 132 /* deprecated, use SYM_FUNC_END, SYM_DATA_END, or SYM_END */ 133 #define END(name) \ 134 .size name, .-name 135 #endif 136 137 #ifndef ENDPROC 138 /* deprecated, use SYM_FUNC_END */ 139 #define ENDPROC(name) \ 140 SYM_FUNC_END(name) 141 #endif 142 #endif /* CONFIG_ARCH_USE_SYM_ANNOTATIONS */ 143 144 /* === generic annotations === */ 145 146 /* SYM_ENTRY -- use only if you have to for non-paired symbols */ 147 #ifndef SYM_ENTRY 148 #define SYM_ENTRY(name, linkage, align...) \ 149 linkage(name) ASM_NL \ 150 align ASM_NL \ 151 name: 152 #endif 153 154 /* SYM_START -- use only if you have to */ 155 #ifndef SYM_START 156 #define SYM_START(name, linkage, align...) \ 157 SYM_ENTRY(name, linkage, align) 158 #endif 159 160 /* SYM_END -- use only if you have to */ 161 #ifndef SYM_END 162 #define SYM_END(name, sym_type) \ 163 .type name sym_type ASM_NL \ 164 .set .L__sym_size_##name, .-name ASM_NL \ 165 .size name, .L__sym_size_##name 166 #endif 167 168 /* SYM_ALIAS -- use only if you have to */ 169 #ifndef SYM_ALIAS 170 #define SYM_ALIAS(alias, name, linkage) \ 171 linkage(alias) ASM_NL \ 172 .set alias, name ASM_NL 173 #endif 174 175 /* === code annotations === */ 176 177 /* 178 * FUNC -- C-like functions (proper stack frame etc.) 179 * CODE -- non-C code (e.g. irq handlers with different, special stack etc.) 180 * 181 * Objtool validates stack for FUNC, but not for CODE. 182 * Objtool generates debug info for both FUNC & CODE, but needs special 183 * annotations for each CODE's start (to describe the actual stack frame). 184 * 185 * Objtool requires that all code must be contained in an ELF symbol. Symbol 186 * names that have a .L prefix do not emit symbol table entries. .L 187 * prefixed symbols can be used within a code region, but should be avoided for 188 * denoting a range of code via ``SYM_*_START/END`` annotations. 189 * 190 * ALIAS -- does not generate debug info -- the aliased function will 191 */ 192 193 /* SYM_INNER_LABEL_ALIGN -- only for labels in the middle of code */ 194 #ifndef SYM_INNER_LABEL_ALIGN 195 #define SYM_INNER_LABEL_ALIGN(name, linkage) \ 196 .type name SYM_T_NONE ASM_NL \ 197 SYM_ENTRY(name, linkage, SYM_A_ALIGN) 198 #endif 199 200 /* SYM_INNER_LABEL -- only for labels in the middle of code */ 201 #ifndef SYM_INNER_LABEL 202 #define SYM_INNER_LABEL(name, linkage) \ 203 .type name SYM_T_NONE ASM_NL \ 204 SYM_ENTRY(name, linkage, SYM_A_NONE) 205 #endif 206 207 /* SYM_FUNC_START -- use for global functions */ 208 #ifndef SYM_FUNC_START 209 #define SYM_FUNC_START(name) \ 210 SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) 211 #endif 212 213 /* SYM_FUNC_START_NOALIGN -- use for global functions, w/o alignment */ 214 #ifndef SYM_FUNC_START_NOALIGN 215 #define SYM_FUNC_START_NOALIGN(name) \ 216 SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) 217 #endif 218 219 /* SYM_FUNC_START_LOCAL -- use for local functions */ 220 #ifndef SYM_FUNC_START_LOCAL 221 #define SYM_FUNC_START_LOCAL(name) \ 222 SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN) 223 #endif 224 225 /* SYM_FUNC_START_LOCAL_NOALIGN -- use for local functions, w/o alignment */ 226 #ifndef SYM_FUNC_START_LOCAL_NOALIGN 227 #define SYM_FUNC_START_LOCAL_NOALIGN(name) \ 228 SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) 229 #endif 230 231 /* SYM_FUNC_START_WEAK -- use for weak functions */ 232 #ifndef SYM_FUNC_START_WEAK 233 #define SYM_FUNC_START_WEAK(name) \ 234 SYM_START(name, SYM_L_WEAK, SYM_A_ALIGN) 235 #endif 236 237 /* SYM_FUNC_START_WEAK_NOALIGN -- use for weak functions, w/o alignment */ 238 #ifndef SYM_FUNC_START_WEAK_NOALIGN 239 #define SYM_FUNC_START_WEAK_NOALIGN(name) \ 240 SYM_START(name, SYM_L_WEAK, SYM_A_NONE) 241 #endif 242 243 /* 244 * SYM_FUNC_END -- the end of SYM_FUNC_START_LOCAL, SYM_FUNC_START, 245 * SYM_FUNC_START_WEAK, ... 246 */ 247 #ifndef SYM_FUNC_END 248 #define SYM_FUNC_END(name) \ 249 SYM_END(name, SYM_T_FUNC) 250 #endif 251 252 /* 253 * SYM_FUNC_ALIAS -- define a global alias for an existing function 254 */ 255 #ifndef SYM_FUNC_ALIAS 256 #define SYM_FUNC_ALIAS(alias, name) \ 257 SYM_ALIAS(alias, name, SYM_L_GLOBAL) 258 #endif 259 260 /* 261 * SYM_FUNC_ALIAS_LOCAL -- define a local alias for an existing function 262 */ 263 #ifndef SYM_FUNC_ALIAS_LOCAL 264 #define SYM_FUNC_ALIAS_LOCAL(alias, name) \ 265 SYM_ALIAS(alias, name, SYM_L_LOCAL) 266 #endif 267 268 /* 269 * SYM_FUNC_ALIAS_WEAK -- define a weak global alias for an existing function 270 */ 271 #ifndef SYM_FUNC_ALIAS_WEAK 272 #define SYM_FUNC_ALIAS_WEAK(alias, name) \ 273 SYM_ALIAS(alias, name, SYM_L_WEAK) 274 #endif 275 276 /* SYM_CODE_START -- use for non-C (special) functions */ 277 #ifndef SYM_CODE_START 278 #define SYM_CODE_START(name) \ 279 SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) 280 #endif 281 282 /* SYM_CODE_START_NOALIGN -- use for non-C (special) functions, w/o alignment */ 283 #ifndef SYM_CODE_START_NOALIGN 284 #define SYM_CODE_START_NOALIGN(name) \ 285 SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) 286 #endif 287 288 /* SYM_CODE_START_LOCAL -- use for local non-C (special) functions */ 289 #ifndef SYM_CODE_START_LOCAL 290 #define SYM_CODE_START_LOCAL(name) \ 291 SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN) 292 #endif 293 294 /* 295 * SYM_CODE_START_LOCAL_NOALIGN -- use for local non-C (special) functions, 296 * w/o alignment 297 */ 298 #ifndef SYM_CODE_START_LOCAL_NOALIGN 299 #define SYM_CODE_START_LOCAL_NOALIGN(name) \ 300 SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) 301 #endif 302 303 /* SYM_CODE_END -- the end of SYM_CODE_START_LOCAL, SYM_CODE_START, ... */ 304 #ifndef SYM_CODE_END 305 #define SYM_CODE_END(name) \ 306 SYM_END(name, SYM_T_NONE) 307 #endif 308 309 /* === data annotations === */ 310 311 /* SYM_DATA_START -- global data symbol */ 312 #ifndef SYM_DATA_START 313 #define SYM_DATA_START(name) \ 314 SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) 315 #endif 316 317 /* SYM_DATA_START -- local data symbol */ 318 #ifndef SYM_DATA_START_LOCAL 319 #define SYM_DATA_START_LOCAL(name) \ 320 SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) 321 #endif 322 323 /* SYM_DATA_END -- the end of SYM_DATA_START symbol */ 324 #ifndef SYM_DATA_END 325 #define SYM_DATA_END(name) \ 326 SYM_END(name, SYM_T_OBJECT) 327 #endif 328 329 /* SYM_DATA_END_LABEL -- the labeled end of SYM_DATA_START symbol */ 330 #ifndef SYM_DATA_END_LABEL 331 #define SYM_DATA_END_LABEL(name, linkage, label) \ 332 linkage(label) ASM_NL \ 333 .type label SYM_T_OBJECT ASM_NL \ 334 label: \ 335 SYM_END(name, SYM_T_OBJECT) 336 #endif 337 338 /* SYM_DATA -- start+end wrapper around simple global data */ 339 #ifndef SYM_DATA 340 #define SYM_DATA(name, data...) \ 341 SYM_DATA_START(name) ASM_NL \ 342 data ASM_NL \ 343 SYM_DATA_END(name) 344 #endif 345 346 /* SYM_DATA_LOCAL -- start+end wrapper around simple local data */ 347 #ifndef SYM_DATA_LOCAL 348 #define SYM_DATA_LOCAL(name, data...) \ 349 SYM_DATA_START_LOCAL(name) ASM_NL \ 350 data ASM_NL \ 351 SYM_DATA_END(name) 352 #endif 353 354 #endif /* __ASSEMBLY__ */ 355 356 #endif /* _LINUX_LINKAGE_H */ 357