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 .align 4,0x90 73 #define __ALIGN_STR ".align 4,0x90" 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 /* If symbol 'name' is treated as a subroutine (gets called, and returns) 138 * then please use ENDPROC to mark 'name' as STT_FUNC for the benefit of 139 * static analysis tools such as stack depth analyzer. 140 */ 141 #ifndef ENDPROC 142 /* deprecated, use SYM_FUNC_END */ 143 #define ENDPROC(name) \ 144 SYM_FUNC_END(name) 145 #endif 146 #endif /* CONFIG_ARCH_USE_SYM_ANNOTATIONS */ 147 148 /* === generic annotations === */ 149 150 /* SYM_ENTRY -- use only if you have to for non-paired symbols */ 151 #ifndef SYM_ENTRY 152 #define SYM_ENTRY(name, linkage, align...) \ 153 linkage(name) ASM_NL \ 154 align ASM_NL \ 155 name: 156 #endif 157 158 /* SYM_START -- use only if you have to */ 159 #ifndef SYM_START 160 #define SYM_START(name, linkage, align...) \ 161 SYM_ENTRY(name, linkage, align) 162 #endif 163 164 /* SYM_END -- use only if you have to */ 165 #ifndef SYM_END 166 #define SYM_END(name, sym_type) \ 167 .type name sym_type ASM_NL \ 168 .size name, .-name 169 #endif 170 171 /* === code annotations === */ 172 173 /* 174 * FUNC -- C-like functions (proper stack frame etc.) 175 * CODE -- non-C code (e.g. irq handlers with different, special stack etc.) 176 * 177 * Objtool validates stack for FUNC, but not for CODE. 178 * Objtool generates debug info for both FUNC & CODE, but needs special 179 * annotations for each CODE's start (to describe the actual stack frame). 180 * 181 * Objtool requires that all code must be contained in an ELF symbol. Symbol 182 * names that have a .L prefix do not emit symbol table entries. .L 183 * prefixed symbols can be used within a code region, but should be avoided for 184 * denoting a range of code via ``SYM_*_START/END`` annotations. 185 * 186 * ALIAS -- does not generate debug info -- the aliased function will 187 */ 188 189 /* SYM_INNER_LABEL_ALIGN -- only for labels in the middle of code */ 190 #ifndef SYM_INNER_LABEL_ALIGN 191 #define SYM_INNER_LABEL_ALIGN(name, linkage) \ 192 .type name SYM_T_NONE ASM_NL \ 193 SYM_ENTRY(name, linkage, SYM_A_ALIGN) 194 #endif 195 196 /* SYM_INNER_LABEL -- only for labels in the middle of code */ 197 #ifndef SYM_INNER_LABEL 198 #define SYM_INNER_LABEL(name, linkage) \ 199 .type name SYM_T_NONE ASM_NL \ 200 SYM_ENTRY(name, linkage, SYM_A_NONE) 201 #endif 202 203 /* 204 * SYM_FUNC_START_LOCAL_ALIAS -- use where there are two local names for one 205 * function 206 */ 207 #ifndef SYM_FUNC_START_LOCAL_ALIAS 208 #define SYM_FUNC_START_LOCAL_ALIAS(name) \ 209 SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN) 210 #endif 211 212 /* 213 * SYM_FUNC_START_ALIAS -- use where there are two global names for one 214 * function 215 */ 216 #ifndef SYM_FUNC_START_ALIAS 217 #define SYM_FUNC_START_ALIAS(name) \ 218 SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) 219 #endif 220 221 /* SYM_FUNC_START -- use for global functions */ 222 #ifndef SYM_FUNC_START 223 /* 224 * The same as SYM_FUNC_START_ALIAS, but we will need to distinguish these two 225 * later. 226 */ 227 #define SYM_FUNC_START(name) \ 228 SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) 229 #endif 230 231 /* SYM_FUNC_START_NOALIGN -- use for global functions, w/o alignment */ 232 #ifndef SYM_FUNC_START_NOALIGN 233 #define SYM_FUNC_START_NOALIGN(name) \ 234 SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) 235 #endif 236 237 /* SYM_FUNC_START_LOCAL -- use for local functions */ 238 #ifndef SYM_FUNC_START_LOCAL 239 /* the same as SYM_FUNC_START_LOCAL_ALIAS, see comment near SYM_FUNC_START */ 240 #define SYM_FUNC_START_LOCAL(name) \ 241 SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN) 242 #endif 243 244 /* SYM_FUNC_START_LOCAL_NOALIGN -- use for local functions, w/o alignment */ 245 #ifndef SYM_FUNC_START_LOCAL_NOALIGN 246 #define SYM_FUNC_START_LOCAL_NOALIGN(name) \ 247 SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) 248 #endif 249 250 /* SYM_FUNC_START_WEAK -- use for weak functions */ 251 #ifndef SYM_FUNC_START_WEAK 252 #define SYM_FUNC_START_WEAK(name) \ 253 SYM_START(name, SYM_L_WEAK, SYM_A_ALIGN) 254 #endif 255 256 /* SYM_FUNC_START_WEAK_NOALIGN -- use for weak functions, w/o alignment */ 257 #ifndef SYM_FUNC_START_WEAK_NOALIGN 258 #define SYM_FUNC_START_WEAK_NOALIGN(name) \ 259 SYM_START(name, SYM_L_WEAK, SYM_A_NONE) 260 #endif 261 262 /* SYM_FUNC_END_ALIAS -- the end of LOCAL_ALIASed or ALIASed function */ 263 #ifndef SYM_FUNC_END_ALIAS 264 #define SYM_FUNC_END_ALIAS(name) \ 265 SYM_END(name, SYM_T_FUNC) 266 #endif 267 268 /* 269 * SYM_FUNC_END -- the end of SYM_FUNC_START_LOCAL, SYM_FUNC_START, 270 * SYM_FUNC_START_WEAK, ... 271 */ 272 #ifndef SYM_FUNC_END 273 /* the same as SYM_FUNC_END_ALIAS, see comment near SYM_FUNC_START */ 274 #define SYM_FUNC_END(name) \ 275 SYM_END(name, SYM_T_FUNC) 276 #endif 277 278 /* SYM_CODE_START -- use for non-C (special) functions */ 279 #ifndef SYM_CODE_START 280 #define SYM_CODE_START(name) \ 281 SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) 282 #endif 283 284 /* SYM_CODE_START_NOALIGN -- use for non-C (special) functions, w/o alignment */ 285 #ifndef SYM_CODE_START_NOALIGN 286 #define SYM_CODE_START_NOALIGN(name) \ 287 SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) 288 #endif 289 290 /* SYM_CODE_START_LOCAL -- use for local non-C (special) functions */ 291 #ifndef SYM_CODE_START_LOCAL 292 #define SYM_CODE_START_LOCAL(name) \ 293 SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN) 294 #endif 295 296 /* 297 * SYM_CODE_START_LOCAL_NOALIGN -- use for local non-C (special) functions, 298 * w/o alignment 299 */ 300 #ifndef SYM_CODE_START_LOCAL_NOALIGN 301 #define SYM_CODE_START_LOCAL_NOALIGN(name) \ 302 SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) 303 #endif 304 305 /* SYM_CODE_END -- the end of SYM_CODE_START_LOCAL, SYM_CODE_START, ... */ 306 #ifndef SYM_CODE_END 307 #define SYM_CODE_END(name) \ 308 SYM_END(name, SYM_T_NONE) 309 #endif 310 311 /* === data annotations === */ 312 313 /* SYM_DATA_START -- global data symbol */ 314 #ifndef SYM_DATA_START 315 #define SYM_DATA_START(name) \ 316 SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) 317 #endif 318 319 /* SYM_DATA_START -- local data symbol */ 320 #ifndef SYM_DATA_START_LOCAL 321 #define SYM_DATA_START_LOCAL(name) \ 322 SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) 323 #endif 324 325 /* SYM_DATA_END -- the end of SYM_DATA_START symbol */ 326 #ifndef SYM_DATA_END 327 #define SYM_DATA_END(name) \ 328 SYM_END(name, SYM_T_OBJECT) 329 #endif 330 331 /* SYM_DATA_END_LABEL -- the labeled end of SYM_DATA_START symbol */ 332 #ifndef SYM_DATA_END_LABEL 333 #define SYM_DATA_END_LABEL(name, linkage, label) \ 334 linkage(label) ASM_NL \ 335 .type label SYM_T_OBJECT ASM_NL \ 336 label: \ 337 SYM_END(name, SYM_T_OBJECT) 338 #endif 339 340 /* SYM_DATA -- start+end wrapper around simple global data */ 341 #ifndef SYM_DATA 342 #define SYM_DATA(name, data...) \ 343 SYM_DATA_START(name) ASM_NL \ 344 data ASM_NL \ 345 SYM_DATA_END(name) 346 #endif 347 348 /* SYM_DATA_LOCAL -- start+end wrapper around simple local data */ 349 #ifndef SYM_DATA_LOCAL 350 #define SYM_DATA_LOCAL(name, data...) \ 351 SYM_DATA_START_LOCAL(name) ASM_NL \ 352 data ASM_NL \ 353 SYM_DATA_END(name) 354 #endif 355 356 #endif /* __ASSEMBLY__ */ 357 358 #endif /* _LINUX_LINKAGE_H */ 359