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 GLOBAL 109 /* deprecated, use SYM_DATA*, SYM_ENTRY, or similar */ 110 #define GLOBAL(name) \ 111 .globl name ASM_NL \ 112 name: 113 #endif 114 115 #ifndef ENTRY 116 /* deprecated, use SYM_FUNC_START */ 117 #define ENTRY(name) \ 118 SYM_FUNC_START(name) 119 #endif 120 #endif /* LINKER_SCRIPT */ 121 122 #ifndef WEAK 123 /* deprecated, use SYM_FUNC_START_WEAK* */ 124 #define WEAK(name) \ 125 SYM_FUNC_START_WEAK(name) 126 #endif 127 128 #ifndef END 129 /* deprecated, use SYM_FUNC_END, SYM_DATA_END, or SYM_END */ 130 #define END(name) \ 131 .size name, .-name 132 #endif 133 134 /* If symbol 'name' is treated as a subroutine (gets called, and returns) 135 * then please use ENDPROC to mark 'name' as STT_FUNC for the benefit of 136 * static analysis tools such as stack depth analyzer. 137 */ 138 #ifndef ENDPROC 139 /* deprecated, use SYM_FUNC_END */ 140 #define ENDPROC(name) \ 141 SYM_FUNC_END(name) 142 #endif 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 .size name, .-name 165 #endif 166 167 /* === code annotations === */ 168 169 /* 170 * FUNC -- C-like functions (proper stack frame etc.) 171 * CODE -- non-C code (e.g. irq handlers with different, special stack etc.) 172 * 173 * Objtool validates stack for FUNC, but not for CODE. 174 * Objtool generates debug info for both FUNC & CODE, but needs special 175 * annotations for each CODE's start (to describe the actual stack frame). 176 * 177 * ALIAS -- does not generate debug info -- the aliased function will 178 */ 179 180 /* SYM_INNER_LABEL_ALIGN -- only for labels in the middle of code */ 181 #ifndef SYM_INNER_LABEL_ALIGN 182 #define SYM_INNER_LABEL_ALIGN(name, linkage) \ 183 .type name SYM_T_NONE ASM_NL \ 184 SYM_ENTRY(name, linkage, SYM_A_ALIGN) 185 #endif 186 187 /* SYM_INNER_LABEL -- only for labels in the middle of code */ 188 #ifndef SYM_INNER_LABEL 189 #define SYM_INNER_LABEL(name, linkage) \ 190 .type name SYM_T_NONE ASM_NL \ 191 SYM_ENTRY(name, linkage, SYM_A_NONE) 192 #endif 193 194 /* 195 * SYM_FUNC_START_LOCAL_ALIAS -- use where there are two local names for one 196 * function 197 */ 198 #ifndef SYM_FUNC_START_LOCAL_ALIAS 199 #define SYM_FUNC_START_LOCAL_ALIAS(name) \ 200 SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN) 201 #endif 202 203 /* 204 * SYM_FUNC_START_ALIAS -- use where there are two global names for one 205 * function 206 */ 207 #ifndef SYM_FUNC_START_ALIAS 208 #define SYM_FUNC_START_ALIAS(name) \ 209 SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) 210 #endif 211 212 /* SYM_FUNC_START -- use for global functions */ 213 #ifndef SYM_FUNC_START 214 /* 215 * The same as SYM_FUNC_START_ALIAS, but we will need to distinguish these two 216 * later. 217 */ 218 #define SYM_FUNC_START(name) \ 219 SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) 220 #endif 221 222 /* SYM_FUNC_START_NOALIGN -- use for global functions, w/o alignment */ 223 #ifndef SYM_FUNC_START_NOALIGN 224 #define SYM_FUNC_START_NOALIGN(name) \ 225 SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) 226 #endif 227 228 /* SYM_FUNC_START_LOCAL -- use for local functions */ 229 #ifndef SYM_FUNC_START_LOCAL 230 /* the same as SYM_FUNC_START_LOCAL_ALIAS, see comment near SYM_FUNC_START */ 231 #define SYM_FUNC_START_LOCAL(name) \ 232 SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN) 233 #endif 234 235 /* SYM_FUNC_START_LOCAL_NOALIGN -- use for local functions, w/o alignment */ 236 #ifndef SYM_FUNC_START_LOCAL_NOALIGN 237 #define SYM_FUNC_START_LOCAL_NOALIGN(name) \ 238 SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) 239 #endif 240 241 /* SYM_FUNC_START_WEAK -- use for weak functions */ 242 #ifndef SYM_FUNC_START_WEAK 243 #define SYM_FUNC_START_WEAK(name) \ 244 SYM_START(name, SYM_L_WEAK, SYM_A_ALIGN) 245 #endif 246 247 /* SYM_FUNC_START_WEAK_NOALIGN -- use for weak functions, w/o alignment */ 248 #ifndef SYM_FUNC_START_WEAK_NOALIGN 249 #define SYM_FUNC_START_WEAK_NOALIGN(name) \ 250 SYM_START(name, SYM_L_WEAK, SYM_A_NONE) 251 #endif 252 253 /* SYM_FUNC_END_ALIAS -- the end of LOCAL_ALIASed or ALIASed function */ 254 #ifndef SYM_FUNC_END_ALIAS 255 #define SYM_FUNC_END_ALIAS(name) \ 256 SYM_END(name, SYM_T_FUNC) 257 #endif 258 259 /* 260 * SYM_FUNC_END -- the end of SYM_FUNC_START_LOCAL, SYM_FUNC_START, 261 * SYM_FUNC_START_WEAK, ... 262 */ 263 #ifndef SYM_FUNC_END 264 /* the same as SYM_FUNC_END_ALIAS, see comment near SYM_FUNC_START */ 265 #define SYM_FUNC_END(name) \ 266 SYM_END(name, SYM_T_FUNC) 267 #endif 268 269 /* SYM_CODE_START -- use for non-C (special) functions */ 270 #ifndef SYM_CODE_START 271 #define SYM_CODE_START(name) \ 272 SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) 273 #endif 274 275 /* SYM_CODE_START_NOALIGN -- use for non-C (special) functions, w/o alignment */ 276 #ifndef SYM_CODE_START_NOALIGN 277 #define SYM_CODE_START_NOALIGN(name) \ 278 SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) 279 #endif 280 281 /* SYM_CODE_START_LOCAL -- use for local non-C (special) functions */ 282 #ifndef SYM_CODE_START_LOCAL 283 #define SYM_CODE_START_LOCAL(name) \ 284 SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN) 285 #endif 286 287 /* 288 * SYM_CODE_START_LOCAL_NOALIGN -- use for local non-C (special) functions, 289 * w/o alignment 290 */ 291 #ifndef SYM_CODE_START_LOCAL_NOALIGN 292 #define SYM_CODE_START_LOCAL_NOALIGN(name) \ 293 SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) 294 #endif 295 296 /* SYM_CODE_END -- the end of SYM_CODE_START_LOCAL, SYM_CODE_START, ... */ 297 #ifndef SYM_CODE_END 298 #define SYM_CODE_END(name) \ 299 SYM_END(name, SYM_T_NONE) 300 #endif 301 302 /* === data annotations === */ 303 304 /* SYM_DATA_START -- global data symbol */ 305 #ifndef SYM_DATA_START 306 #define SYM_DATA_START(name) \ 307 SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) 308 #endif 309 310 /* SYM_DATA_START -- local data symbol */ 311 #ifndef SYM_DATA_START_LOCAL 312 #define SYM_DATA_START_LOCAL(name) \ 313 SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) 314 #endif 315 316 /* SYM_DATA_END -- the end of SYM_DATA_START symbol */ 317 #ifndef SYM_DATA_END 318 #define SYM_DATA_END(name) \ 319 SYM_END(name, SYM_T_OBJECT) 320 #endif 321 322 /* SYM_DATA_END_LABEL -- the labeled end of SYM_DATA_START symbol */ 323 #ifndef SYM_DATA_END_LABEL 324 #define SYM_DATA_END_LABEL(name, linkage, label) \ 325 linkage(label) ASM_NL \ 326 .type label SYM_T_OBJECT ASM_NL \ 327 label: \ 328 SYM_END(name, SYM_T_OBJECT) 329 #endif 330 331 /* SYM_DATA -- start+end wrapper around simple global data */ 332 #ifndef SYM_DATA 333 #define SYM_DATA(name, data...) \ 334 SYM_DATA_START(name) ASM_NL \ 335 data ASM_NL \ 336 SYM_DATA_END(name) 337 #endif 338 339 /* SYM_DATA_LOCAL -- start+end wrapper around simple local data */ 340 #ifndef SYM_DATA_LOCAL 341 #define SYM_DATA_LOCAL(name, data...) \ 342 SYM_DATA_START_LOCAL(name) ASM_NL \ 343 data ASM_NL \ 344 SYM_DATA_END(name) 345 #endif 346 347 #endif /* __ASSEMBLY__ */ 348 349 #endif /* _LINUX_LINKAGE_H */ 350