1 /* 2 * Helper macros to support writing architecture specific 3 * linker scripts. 4 * 5 * A minimal linker scripts has following content: 6 * [This is a sample, architectures may have special requiriements] 7 * 8 * OUTPUT_FORMAT(...) 9 * OUTPUT_ARCH(...) 10 * ENTRY(...) 11 * SECTIONS 12 * { 13 * . = START; 14 * __init_begin = .; 15 * HEAD_TEXT_SECTION 16 * INIT_TEXT_SECTION(PAGE_SIZE) 17 * INIT_DATA_SECTION(...) 18 * PERCPU_SECTION(CACHELINE_SIZE) 19 * __init_end = .; 20 * 21 * _stext = .; 22 * TEXT_SECTION = 0 23 * _etext = .; 24 * 25 * _sdata = .; 26 * RO_DATA(PAGE_SIZE) 27 * RW_DATA(...) 28 * _edata = .; 29 * 30 * EXCEPTION_TABLE(...) 31 * 32 * BSS_SECTION(0, 0, 0) 33 * _end = .; 34 * 35 * STABS_DEBUG 36 * DWARF_DEBUG 37 * ELF_DETAILS 38 * 39 * DISCARDS // must be the last 40 * } 41 * 42 * [__init_begin, __init_end] is the init section that may be freed after init 43 * // __init_begin and __init_end should be page aligned, so that we can 44 * // free the whole .init memory 45 * [_stext, _etext] is the text section 46 * [_sdata, _edata] is the data section 47 * 48 * Some of the included output section have their own set of constants. 49 * Examples are: [__initramfs_start, __initramfs_end] for initramfs and 50 * [__nosave_begin, __nosave_end] for the nosave data 51 */ 52 53 #ifndef LOAD_OFFSET 54 #define LOAD_OFFSET 0 55 #endif 56 57 /* 58 * Only some architectures want to have the .notes segment visible in 59 * a separate PT_NOTE ELF Program Header. When this happens, it needs 60 * to be visible in both the kernel text's PT_LOAD and the PT_NOTE 61 * Program Headers. In this case, though, the PT_LOAD needs to be made 62 * the default again so that all the following sections don't also end 63 * up in the PT_NOTE Program Header. 64 */ 65 #ifdef EMITS_PT_NOTE 66 #define NOTES_HEADERS :text :note 67 #define NOTES_HEADERS_RESTORE __restore_ph : { *(.__restore_ph) } :text 68 #else 69 #define NOTES_HEADERS 70 #define NOTES_HEADERS_RESTORE 71 #endif 72 73 /* 74 * Some architectures have non-executable read-only exception tables. 75 * They can be added to the RO_DATA segment by specifying their desired 76 * alignment. 77 */ 78 #ifdef RO_EXCEPTION_TABLE_ALIGN 79 #define RO_EXCEPTION_TABLE EXCEPTION_TABLE(RO_EXCEPTION_TABLE_ALIGN) 80 #else 81 #define RO_EXCEPTION_TABLE 82 #endif 83 84 /* Align . function alignment. */ 85 #define ALIGN_FUNCTION() . = ALIGN(CONFIG_FUNCTION_ALIGNMENT) 86 87 /* 88 * LD_DEAD_CODE_DATA_ELIMINATION option enables -fdata-sections, which 89 * generates .data.identifier sections, which need to be pulled in with 90 * .data. We don't want to pull in .data..other sections, which Linux 91 * has defined. Same for text and bss. 92 * 93 * With LTO_CLANG, the linker also splits sections by default, so we need 94 * these macros to combine the sections during the final link. 95 * 96 * RODATA_MAIN is not used because existing code already defines .rodata.x 97 * sections to be brought in with rodata. 98 */ 99 #if defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || defined(CONFIG_LTO_CLANG) 100 #define TEXT_MAIN .text .text.[0-9a-zA-Z_]* 101 #define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data..L* .data..compoundliteral* .data.$__unnamed_* .data.$L* 102 #define SDATA_MAIN .sdata .sdata.[0-9a-zA-Z_]* 103 #define RODATA_MAIN .rodata .rodata.[0-9a-zA-Z_]* .rodata..L* 104 #define BSS_MAIN .bss .bss.[0-9a-zA-Z_]* .bss..compoundliteral* 105 #define SBSS_MAIN .sbss .sbss.[0-9a-zA-Z_]* 106 #else 107 #define TEXT_MAIN .text 108 #define DATA_MAIN .data 109 #define SDATA_MAIN .sdata 110 #define RODATA_MAIN .rodata 111 #define BSS_MAIN .bss 112 #define SBSS_MAIN .sbss 113 #endif 114 115 /* 116 * GCC 4.5 and later have a 32 bytes section alignment for structures. 117 * Except GCC 4.9, that feels the need to align on 64 bytes. 118 */ 119 #define STRUCT_ALIGNMENT 32 120 #define STRUCT_ALIGN() . = ALIGN(STRUCT_ALIGNMENT) 121 122 /* 123 * The order of the sched class addresses are important, as they are 124 * used to determine the order of the priority of each sched class in 125 * relation to each other. 126 */ 127 #define SCHED_DATA \ 128 STRUCT_ALIGN(); \ 129 __sched_class_highest = .; \ 130 *(__stop_sched_class) \ 131 *(__dl_sched_class) \ 132 *(__rt_sched_class) \ 133 *(__fair_sched_class) \ 134 *(__idle_sched_class) \ 135 __sched_class_lowest = .; 136 137 /* The actual configuration determine if the init/exit sections 138 * are handled as text/data or they can be discarded (which 139 * often happens at runtime) 140 */ 141 #ifdef CONFIG_HOTPLUG_CPU 142 #define CPU_KEEP(sec) *(.cpu##sec) 143 #define CPU_DISCARD(sec) 144 #else 145 #define CPU_KEEP(sec) 146 #define CPU_DISCARD(sec) *(.cpu##sec) 147 #endif 148 149 #if defined(CONFIG_MEMORY_HOTPLUG) 150 #define MEM_KEEP(sec) *(.mem##sec) 151 #define MEM_DISCARD(sec) 152 #else 153 #define MEM_KEEP(sec) 154 #define MEM_DISCARD(sec) *(.mem##sec) 155 #endif 156 157 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_NO_PATCHABLE 158 #define KEEP_PATCHABLE KEEP(*(__patchable_function_entries)) 159 #define PATCHABLE_DISCARDS 160 #else 161 #define KEEP_PATCHABLE 162 #define PATCHABLE_DISCARDS *(__patchable_function_entries) 163 #endif 164 165 #ifndef CONFIG_ARCH_SUPPORTS_CFI_CLANG 166 /* 167 * Simply points to ftrace_stub, but with the proper protocol. 168 * Defined by the linker script in linux/vmlinux.lds.h 169 */ 170 #define FTRACE_STUB_HACK ftrace_stub_graph = ftrace_stub; 171 #else 172 #define FTRACE_STUB_HACK 173 #endif 174 175 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 176 /* 177 * The ftrace call sites are logged to a section whose name depends on the 178 * compiler option used. A given kernel image will only use one, AKA 179 * FTRACE_CALLSITE_SECTION. We capture all of them here to avoid header 180 * dependencies for FTRACE_CALLSITE_SECTION's definition. 181 * 182 * ftrace_ops_list_func will be defined as arch_ftrace_ops_list_func 183 * as some archs will have a different prototype for that function 184 * but ftrace_ops_list_func() will have a single prototype. 185 */ 186 #define MCOUNT_REC() . = ALIGN(8); \ 187 __start_mcount_loc = .; \ 188 KEEP(*(__mcount_loc)) \ 189 KEEP_PATCHABLE \ 190 __stop_mcount_loc = .; \ 191 FTRACE_STUB_HACK \ 192 ftrace_ops_list_func = arch_ftrace_ops_list_func; 193 #else 194 # ifdef CONFIG_FUNCTION_TRACER 195 # define MCOUNT_REC() FTRACE_STUB_HACK \ 196 ftrace_ops_list_func = arch_ftrace_ops_list_func; 197 # else 198 # define MCOUNT_REC() 199 # endif 200 #endif 201 202 #define BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_) \ 203 _BEGIN_##_label_ = .; \ 204 KEEP(*(_sec_)) \ 205 _END_##_label_ = .; 206 207 #define BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_) \ 208 _label_##_BEGIN_ = .; \ 209 KEEP(*(_sec_)) \ 210 _label_##_END_ = .; 211 212 #define BOUNDED_SECTION_BY(_sec_, _label_) \ 213 BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, __start, __stop) 214 215 #define BOUNDED_SECTION(_sec) BOUNDED_SECTION_BY(_sec, _sec) 216 217 #define HEADERED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_, _HDR_) \ 218 _HDR_##_label_ = .; \ 219 KEEP(*(.gnu.linkonce.##_sec_)) \ 220 BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_) 221 222 #define HEADERED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_, _HDR_) \ 223 _label_##_HDR_ = .; \ 224 KEEP(*(.gnu.linkonce.##_sec_)) \ 225 BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_) 226 227 #define HEADERED_SECTION_BY(_sec_, _label_) \ 228 HEADERED_SECTION_PRE_LABEL(_sec_, _label_, __start, __stop) 229 230 #define HEADERED_SECTION(_sec) HEADERED_SECTION_BY(_sec, _sec) 231 232 #ifdef CONFIG_TRACE_BRANCH_PROFILING 233 #define LIKELY_PROFILE() \ 234 BOUNDED_SECTION_BY(_ftrace_annotated_branch, _annotated_branch_profile) 235 #else 236 #define LIKELY_PROFILE() 237 #endif 238 239 #ifdef CONFIG_PROFILE_ALL_BRANCHES 240 #define BRANCH_PROFILE() \ 241 BOUNDED_SECTION_BY(_ftrace_branch, _branch_profile) 242 #else 243 #define BRANCH_PROFILE() 244 #endif 245 246 #ifdef CONFIG_KPROBES 247 #define KPROBE_BLACKLIST() \ 248 . = ALIGN(8); \ 249 BOUNDED_SECTION(_kprobe_blacklist) 250 #else 251 #define KPROBE_BLACKLIST() 252 #endif 253 254 #ifdef CONFIG_FUNCTION_ERROR_INJECTION 255 #define ERROR_INJECT_WHITELIST() \ 256 STRUCT_ALIGN(); \ 257 BOUNDED_SECTION(_error_injection_whitelist) 258 #else 259 #define ERROR_INJECT_WHITELIST() 260 #endif 261 262 #ifdef CONFIG_EVENT_TRACING 263 #define FTRACE_EVENTS() \ 264 . = ALIGN(8); \ 265 BOUNDED_SECTION(_ftrace_events) \ 266 BOUNDED_SECTION_BY(_ftrace_eval_map, _ftrace_eval_maps) 267 #else 268 #define FTRACE_EVENTS() 269 #endif 270 271 #ifdef CONFIG_TRACING 272 #define TRACE_PRINTKS() BOUNDED_SECTION_BY(__trace_printk_fmt, ___trace_bprintk_fmt) 273 #define TRACEPOINT_STR() BOUNDED_SECTION_BY(__tracepoint_str, ___tracepoint_str) 274 #else 275 #define TRACE_PRINTKS() 276 #define TRACEPOINT_STR() 277 #endif 278 279 #ifdef CONFIG_FTRACE_SYSCALLS 280 #define TRACE_SYSCALLS() \ 281 . = ALIGN(8); \ 282 BOUNDED_SECTION_BY(__syscalls_metadata, _syscalls_metadata) 283 #else 284 #define TRACE_SYSCALLS() 285 #endif 286 287 #ifdef CONFIG_BPF_EVENTS 288 #define BPF_RAW_TP() STRUCT_ALIGN(); \ 289 BOUNDED_SECTION_BY(__bpf_raw_tp_map, __bpf_raw_tp) 290 #else 291 #define BPF_RAW_TP() 292 #endif 293 294 #ifdef CONFIG_SERIAL_EARLYCON 295 #define EARLYCON_TABLE() \ 296 . = ALIGN(8); \ 297 BOUNDED_SECTION_POST_LABEL(__earlycon_table, __earlycon_table, , _end) 298 #else 299 #define EARLYCON_TABLE() 300 #endif 301 302 #ifdef CONFIG_SECURITY 303 #define LSM_TABLE() \ 304 . = ALIGN(8); \ 305 BOUNDED_SECTION_PRE_LABEL(.lsm_info.init, _lsm_info, __start, __end) 306 307 #define EARLY_LSM_TABLE() \ 308 . = ALIGN(8); \ 309 BOUNDED_SECTION_PRE_LABEL(.early_lsm_info.init, _early_lsm_info, __start, __end) 310 #else 311 #define LSM_TABLE() 312 #define EARLY_LSM_TABLE() 313 #endif 314 315 #define ___OF_TABLE(cfg, name) _OF_TABLE_##cfg(name) 316 #define __OF_TABLE(cfg, name) ___OF_TABLE(cfg, name) 317 #define OF_TABLE(cfg, name) __OF_TABLE(IS_ENABLED(cfg), name) 318 #define _OF_TABLE_0(name) 319 #define _OF_TABLE_1(name) \ 320 . = ALIGN(8); \ 321 __##name##_of_table = .; \ 322 KEEP(*(__##name##_of_table)) \ 323 KEEP(*(__##name##_of_table_end)) 324 325 #define TIMER_OF_TABLES() OF_TABLE(CONFIG_TIMER_OF, timer) 326 #define IRQCHIP_OF_MATCH_TABLE() OF_TABLE(CONFIG_IRQCHIP, irqchip) 327 #define CLK_OF_TABLES() OF_TABLE(CONFIG_COMMON_CLK, clk) 328 #define RESERVEDMEM_OF_TABLES() OF_TABLE(CONFIG_OF_RESERVED_MEM, reservedmem) 329 #define CPU_METHOD_OF_TABLES() OF_TABLE(CONFIG_SMP, cpu_method) 330 #define CPUIDLE_METHOD_OF_TABLES() OF_TABLE(CONFIG_CPU_IDLE, cpuidle_method) 331 332 #ifdef CONFIG_ACPI 333 #define ACPI_PROBE_TABLE(name) \ 334 . = ALIGN(8); \ 335 BOUNDED_SECTION_POST_LABEL(__##name##_acpi_probe_table, \ 336 __##name##_acpi_probe_table,, _end) 337 #else 338 #define ACPI_PROBE_TABLE(name) 339 #endif 340 341 #ifdef CONFIG_THERMAL 342 #define THERMAL_TABLE(name) \ 343 . = ALIGN(8); \ 344 BOUNDED_SECTION_POST_LABEL(__##name##_thermal_table, \ 345 __##name##_thermal_table,, _end) 346 #else 347 #define THERMAL_TABLE(name) 348 #endif 349 350 #define KERNEL_DTB() \ 351 STRUCT_ALIGN(); \ 352 __dtb_start = .; \ 353 KEEP(*(.dtb.init.rodata)) \ 354 __dtb_end = .; 355 356 /* 357 * .data section 358 */ 359 #define DATA_DATA \ 360 *(.xiptext) \ 361 *(DATA_MAIN) \ 362 *(.data..decrypted) \ 363 *(.ref.data) \ 364 *(.data..shared_aligned) /* percpu related */ \ 365 MEM_KEEP(init.data*) \ 366 MEM_KEEP(exit.data*) \ 367 *(.data.unlikely) \ 368 __start_once = .; \ 369 *(.data.once) \ 370 __end_once = .; \ 371 STRUCT_ALIGN(); \ 372 *(__tracepoints) \ 373 /* implement dynamic printk debug */ \ 374 . = ALIGN(8); \ 375 BOUNDED_SECTION_BY(__dyndbg_classes, ___dyndbg_classes) \ 376 BOUNDED_SECTION_BY(__dyndbg, ___dyndbg) \ 377 LIKELY_PROFILE() \ 378 BRANCH_PROFILE() \ 379 TRACE_PRINTKS() \ 380 BPF_RAW_TP() \ 381 TRACEPOINT_STR() 382 383 /* 384 * Data section helpers 385 */ 386 #define NOSAVE_DATA \ 387 . = ALIGN(PAGE_SIZE); \ 388 __nosave_begin = .; \ 389 *(.data..nosave) \ 390 . = ALIGN(PAGE_SIZE); \ 391 __nosave_end = .; 392 393 #define PAGE_ALIGNED_DATA(page_align) \ 394 . = ALIGN(page_align); \ 395 *(.data..page_aligned) \ 396 . = ALIGN(page_align); 397 398 #define READ_MOSTLY_DATA(align) \ 399 . = ALIGN(align); \ 400 *(.data..read_mostly) \ 401 . = ALIGN(align); 402 403 #define CACHELINE_ALIGNED_DATA(align) \ 404 . = ALIGN(align); \ 405 *(.data..cacheline_aligned) 406 407 #define INIT_TASK_DATA(align) \ 408 . = ALIGN(align); \ 409 __start_init_task = .; \ 410 init_thread_union = .; \ 411 init_stack = .; \ 412 KEEP(*(.data..init_task)) \ 413 KEEP(*(.data..init_thread_info)) \ 414 . = __start_init_task + THREAD_SIZE; \ 415 __end_init_task = .; 416 417 #define JUMP_TABLE_DATA \ 418 . = ALIGN(8); \ 419 BOUNDED_SECTION_BY(__jump_table, ___jump_table) 420 421 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE 422 #define STATIC_CALL_DATA \ 423 . = ALIGN(8); \ 424 BOUNDED_SECTION_BY(.static_call_sites, _static_call_sites) \ 425 BOUNDED_SECTION_BY(.static_call_tramp_key, _static_call_tramp_key) 426 #else 427 #define STATIC_CALL_DATA 428 #endif 429 430 /* 431 * Allow architectures to handle ro_after_init data on their 432 * own by defining an empty RO_AFTER_INIT_DATA. 433 */ 434 #ifndef RO_AFTER_INIT_DATA 435 #define RO_AFTER_INIT_DATA \ 436 . = ALIGN(8); \ 437 __start_ro_after_init = .; \ 438 *(.data..ro_after_init) \ 439 JUMP_TABLE_DATA \ 440 STATIC_CALL_DATA \ 441 __end_ro_after_init = .; 442 #endif 443 444 /* 445 * .kcfi_traps contains a list KCFI trap locations. 446 */ 447 #ifndef KCFI_TRAPS 448 #ifdef CONFIG_ARCH_USES_CFI_TRAPS 449 #define KCFI_TRAPS \ 450 __kcfi_traps : AT(ADDR(__kcfi_traps) - LOAD_OFFSET) { \ 451 BOUNDED_SECTION_BY(.kcfi_traps, ___kcfi_traps) \ 452 } 453 #else 454 #define KCFI_TRAPS 455 #endif 456 #endif 457 458 /* 459 * Read only Data 460 */ 461 #define RO_DATA(align) \ 462 . = ALIGN((align)); \ 463 .rodata : AT(ADDR(.rodata) - LOAD_OFFSET) { \ 464 __start_rodata = .; \ 465 *(.rodata) *(.rodata.*) \ 466 SCHED_DATA \ 467 RO_AFTER_INIT_DATA /* Read only after init */ \ 468 . = ALIGN(8); \ 469 BOUNDED_SECTION_BY(__tracepoints_ptrs, ___tracepoints_ptrs) \ 470 *(__tracepoints_strings)/* Tracepoints: strings */ \ 471 } \ 472 \ 473 .rodata1 : AT(ADDR(.rodata1) - LOAD_OFFSET) { \ 474 *(.rodata1) \ 475 } \ 476 \ 477 /* PCI quirks */ \ 478 .pci_fixup : AT(ADDR(.pci_fixup) - LOAD_OFFSET) { \ 479 BOUNDED_SECTION_PRE_LABEL(.pci_fixup_early, _pci_fixups_early, __start, __end) \ 480 BOUNDED_SECTION_PRE_LABEL(.pci_fixup_header, _pci_fixups_header, __start, __end) \ 481 BOUNDED_SECTION_PRE_LABEL(.pci_fixup_final, _pci_fixups_final, __start, __end) \ 482 BOUNDED_SECTION_PRE_LABEL(.pci_fixup_enable, _pci_fixups_enable, __start, __end) \ 483 BOUNDED_SECTION_PRE_LABEL(.pci_fixup_resume, _pci_fixups_resume, __start, __end) \ 484 BOUNDED_SECTION_PRE_LABEL(.pci_fixup_suspend, _pci_fixups_suspend, __start, __end) \ 485 BOUNDED_SECTION_PRE_LABEL(.pci_fixup_resume_early, _pci_fixups_resume_early, __start, __end) \ 486 BOUNDED_SECTION_PRE_LABEL(.pci_fixup_suspend_late, _pci_fixups_suspend_late, __start, __end) \ 487 } \ 488 \ 489 FW_LOADER_BUILT_IN_DATA \ 490 TRACEDATA \ 491 \ 492 PRINTK_INDEX \ 493 \ 494 /* Kernel symbol table: Normal symbols */ \ 495 __ksymtab : AT(ADDR(__ksymtab) - LOAD_OFFSET) { \ 496 __start___ksymtab = .; \ 497 KEEP(*(SORT(___ksymtab+*))) \ 498 __stop___ksymtab = .; \ 499 } \ 500 \ 501 /* Kernel symbol table: GPL-only symbols */ \ 502 __ksymtab_gpl : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) { \ 503 __start___ksymtab_gpl = .; \ 504 KEEP(*(SORT(___ksymtab_gpl+*))) \ 505 __stop___ksymtab_gpl = .; \ 506 } \ 507 \ 508 /* Kernel symbol table: Normal symbols */ \ 509 __kcrctab : AT(ADDR(__kcrctab) - LOAD_OFFSET) { \ 510 __start___kcrctab = .; \ 511 KEEP(*(SORT(___kcrctab+*))) \ 512 __stop___kcrctab = .; \ 513 } \ 514 \ 515 /* Kernel symbol table: GPL-only symbols */ \ 516 __kcrctab_gpl : AT(ADDR(__kcrctab_gpl) - LOAD_OFFSET) { \ 517 __start___kcrctab_gpl = .; \ 518 KEEP(*(SORT(___kcrctab_gpl+*))) \ 519 __stop___kcrctab_gpl = .; \ 520 } \ 521 \ 522 /* Kernel symbol table: strings */ \ 523 __ksymtab_strings : AT(ADDR(__ksymtab_strings) - LOAD_OFFSET) { \ 524 *(__ksymtab_strings) \ 525 } \ 526 \ 527 /* __*init sections */ \ 528 __init_rodata : AT(ADDR(__init_rodata) - LOAD_OFFSET) { \ 529 *(.ref.rodata) \ 530 MEM_KEEP(init.rodata) \ 531 MEM_KEEP(exit.rodata) \ 532 } \ 533 \ 534 /* Built-in module parameters. */ \ 535 __param : AT(ADDR(__param) - LOAD_OFFSET) { \ 536 BOUNDED_SECTION_BY(__param, ___param) \ 537 } \ 538 \ 539 /* Built-in module versions. */ \ 540 __modver : AT(ADDR(__modver) - LOAD_OFFSET) { \ 541 BOUNDED_SECTION_BY(__modver, ___modver) \ 542 } \ 543 \ 544 KCFI_TRAPS \ 545 \ 546 RO_EXCEPTION_TABLE \ 547 NOTES \ 548 BTF \ 549 \ 550 . = ALIGN((align)); \ 551 __end_rodata = .; 552 553 554 /* 555 * Non-instrumentable text section 556 */ 557 #define NOINSTR_TEXT \ 558 ALIGN_FUNCTION(); \ 559 __noinstr_text_start = .; \ 560 *(.noinstr.text) \ 561 __cpuidle_text_start = .; \ 562 *(.cpuidle.text) \ 563 __cpuidle_text_end = .; \ 564 __noinstr_text_end = .; 565 566 /* 567 * .text section. Map to function alignment to avoid address changes 568 * during second ld run in second ld pass when generating System.map 569 * 570 * TEXT_MAIN here will match .text.fixup and .text.unlikely if dead 571 * code elimination is enabled, so these sections should be converted 572 * to use ".." first. 573 */ 574 #define TEXT_TEXT \ 575 ALIGN_FUNCTION(); \ 576 *(.text.hot .text.hot.*) \ 577 *(TEXT_MAIN .text.fixup) \ 578 *(.text.unlikely .text.unlikely.*) \ 579 *(.text.unknown .text.unknown.*) \ 580 NOINSTR_TEXT \ 581 *(.text..refcount) \ 582 *(.ref.text) \ 583 *(.text.asan.* .text.tsan.*) \ 584 MEM_KEEP(init.text*) \ 585 MEM_KEEP(exit.text*) \ 586 587 588 /* sched.text is aling to function alignment to secure we have same 589 * address even at second ld pass when generating System.map */ 590 #define SCHED_TEXT \ 591 ALIGN_FUNCTION(); \ 592 __sched_text_start = .; \ 593 *(.sched.text) \ 594 __sched_text_end = .; 595 596 /* spinlock.text is aling to function alignment to secure we have same 597 * address even at second ld pass when generating System.map */ 598 #define LOCK_TEXT \ 599 ALIGN_FUNCTION(); \ 600 __lock_text_start = .; \ 601 *(.spinlock.text) \ 602 __lock_text_end = .; 603 604 #define KPROBES_TEXT \ 605 ALIGN_FUNCTION(); \ 606 __kprobes_text_start = .; \ 607 *(.kprobes.text) \ 608 __kprobes_text_end = .; 609 610 #define ENTRY_TEXT \ 611 ALIGN_FUNCTION(); \ 612 __entry_text_start = .; \ 613 *(.entry.text) \ 614 __entry_text_end = .; 615 616 #define IRQENTRY_TEXT \ 617 ALIGN_FUNCTION(); \ 618 __irqentry_text_start = .; \ 619 *(.irqentry.text) \ 620 __irqentry_text_end = .; 621 622 #define SOFTIRQENTRY_TEXT \ 623 ALIGN_FUNCTION(); \ 624 __softirqentry_text_start = .; \ 625 *(.softirqentry.text) \ 626 __softirqentry_text_end = .; 627 628 #define STATIC_CALL_TEXT \ 629 ALIGN_FUNCTION(); \ 630 __static_call_text_start = .; \ 631 *(.static_call.text) \ 632 __static_call_text_end = .; 633 634 /* Section used for early init (in .S files) */ 635 #define HEAD_TEXT KEEP(*(.head.text)) 636 637 #define HEAD_TEXT_SECTION \ 638 .head.text : AT(ADDR(.head.text) - LOAD_OFFSET) { \ 639 HEAD_TEXT \ 640 } 641 642 /* 643 * Exception table 644 */ 645 #define EXCEPTION_TABLE(align) \ 646 . = ALIGN(align); \ 647 __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) { \ 648 BOUNDED_SECTION_BY(__ex_table, ___ex_table) \ 649 } 650 651 /* 652 * .BTF 653 */ 654 #ifdef CONFIG_DEBUG_INFO_BTF 655 #define BTF \ 656 .BTF : AT(ADDR(.BTF) - LOAD_OFFSET) { \ 657 BOUNDED_SECTION_BY(.BTF, _BTF) \ 658 } \ 659 . = ALIGN(4); \ 660 .BTF_ids : AT(ADDR(.BTF_ids) - LOAD_OFFSET) { \ 661 *(.BTF_ids) \ 662 } 663 #else 664 #define BTF 665 #endif 666 667 /* 668 * Init task 669 */ 670 #define INIT_TASK_DATA_SECTION(align) \ 671 . = ALIGN(align); \ 672 .data..init_task : AT(ADDR(.data..init_task) - LOAD_OFFSET) { \ 673 INIT_TASK_DATA(align) \ 674 } 675 676 #ifdef CONFIG_CONSTRUCTORS 677 #define KERNEL_CTORS() . = ALIGN(8); \ 678 __ctors_start = .; \ 679 KEEP(*(SORT(.ctors.*))) \ 680 KEEP(*(.ctors)) \ 681 KEEP(*(SORT(.init_array.*))) \ 682 KEEP(*(.init_array)) \ 683 __ctors_end = .; 684 #else 685 #define KERNEL_CTORS() 686 #endif 687 688 /* init and exit section handling */ 689 #define INIT_DATA \ 690 KEEP(*(SORT(___kentry+*))) \ 691 *(.init.data init.data.*) \ 692 MEM_DISCARD(init.data*) \ 693 KERNEL_CTORS() \ 694 MCOUNT_REC() \ 695 *(.init.rodata .init.rodata.*) \ 696 FTRACE_EVENTS() \ 697 TRACE_SYSCALLS() \ 698 KPROBE_BLACKLIST() \ 699 ERROR_INJECT_WHITELIST() \ 700 MEM_DISCARD(init.rodata) \ 701 CLK_OF_TABLES() \ 702 RESERVEDMEM_OF_TABLES() \ 703 TIMER_OF_TABLES() \ 704 CPU_METHOD_OF_TABLES() \ 705 CPUIDLE_METHOD_OF_TABLES() \ 706 KERNEL_DTB() \ 707 IRQCHIP_OF_MATCH_TABLE() \ 708 ACPI_PROBE_TABLE(irqchip) \ 709 ACPI_PROBE_TABLE(timer) \ 710 THERMAL_TABLE(governor) \ 711 EARLYCON_TABLE() \ 712 LSM_TABLE() \ 713 EARLY_LSM_TABLE() \ 714 KUNIT_TABLE() 715 716 #define INIT_TEXT \ 717 *(.init.text .init.text.*) \ 718 *(.text.startup) \ 719 MEM_DISCARD(init.text*) 720 721 #define EXIT_DATA \ 722 *(.exit.data .exit.data.*) \ 723 *(.fini_array .fini_array.*) \ 724 *(.dtors .dtors.*) \ 725 MEM_DISCARD(exit.data*) \ 726 MEM_DISCARD(exit.rodata*) 727 728 #define EXIT_TEXT \ 729 *(.exit.text) \ 730 *(.text.exit) \ 731 MEM_DISCARD(exit.text) 732 733 #define EXIT_CALL \ 734 *(.exitcall.exit) 735 736 /* 737 * bss (Block Started by Symbol) - uninitialized data 738 * zeroed during startup 739 */ 740 #define SBSS(sbss_align) \ 741 . = ALIGN(sbss_align); \ 742 .sbss : AT(ADDR(.sbss) - LOAD_OFFSET) { \ 743 *(.dynsbss) \ 744 *(SBSS_MAIN) \ 745 *(.scommon) \ 746 } 747 748 /* 749 * Allow archectures to redefine BSS_FIRST_SECTIONS to add extra 750 * sections to the front of bss. 751 */ 752 #ifndef BSS_FIRST_SECTIONS 753 #define BSS_FIRST_SECTIONS 754 #endif 755 756 #define BSS(bss_align) \ 757 . = ALIGN(bss_align); \ 758 .bss : AT(ADDR(.bss) - LOAD_OFFSET) { \ 759 BSS_FIRST_SECTIONS \ 760 . = ALIGN(PAGE_SIZE); \ 761 *(.bss..page_aligned) \ 762 . = ALIGN(PAGE_SIZE); \ 763 *(.dynbss) \ 764 *(BSS_MAIN) \ 765 *(COMMON) \ 766 } 767 768 /* 769 * DWARF debug sections. 770 * Symbols in the DWARF debugging sections are relative to 771 * the beginning of the section so we begin them at 0. 772 */ 773 #define DWARF_DEBUG \ 774 /* DWARF 1 */ \ 775 .debug 0 : { *(.debug) } \ 776 .line 0 : { *(.line) } \ 777 /* GNU DWARF 1 extensions */ \ 778 .debug_srcinfo 0 : { *(.debug_srcinfo) } \ 779 .debug_sfnames 0 : { *(.debug_sfnames) } \ 780 /* DWARF 1.1 and DWARF 2 */ \ 781 .debug_aranges 0 : { *(.debug_aranges) } \ 782 .debug_pubnames 0 : { *(.debug_pubnames) } \ 783 /* DWARF 2 */ \ 784 .debug_info 0 : { *(.debug_info \ 785 .gnu.linkonce.wi.*) } \ 786 .debug_abbrev 0 : { *(.debug_abbrev) } \ 787 .debug_line 0 : { *(.debug_line) } \ 788 .debug_frame 0 : { *(.debug_frame) } \ 789 .debug_str 0 : { *(.debug_str) } \ 790 .debug_loc 0 : { *(.debug_loc) } \ 791 .debug_macinfo 0 : { *(.debug_macinfo) } \ 792 .debug_pubtypes 0 : { *(.debug_pubtypes) } \ 793 /* DWARF 3 */ \ 794 .debug_ranges 0 : { *(.debug_ranges) } \ 795 /* SGI/MIPS DWARF 2 extensions */ \ 796 .debug_weaknames 0 : { *(.debug_weaknames) } \ 797 .debug_funcnames 0 : { *(.debug_funcnames) } \ 798 .debug_typenames 0 : { *(.debug_typenames) } \ 799 .debug_varnames 0 : { *(.debug_varnames) } \ 800 /* GNU DWARF 2 extensions */ \ 801 .debug_gnu_pubnames 0 : { *(.debug_gnu_pubnames) } \ 802 .debug_gnu_pubtypes 0 : { *(.debug_gnu_pubtypes) } \ 803 /* DWARF 4 */ \ 804 .debug_types 0 : { *(.debug_types) } \ 805 /* DWARF 5 */ \ 806 .debug_addr 0 : { *(.debug_addr) } \ 807 .debug_line_str 0 : { *(.debug_line_str) } \ 808 .debug_loclists 0 : { *(.debug_loclists) } \ 809 .debug_macro 0 : { *(.debug_macro) } \ 810 .debug_names 0 : { *(.debug_names) } \ 811 .debug_rnglists 0 : { *(.debug_rnglists) } \ 812 .debug_str_offsets 0 : { *(.debug_str_offsets) } 813 814 /* Stabs debugging sections. */ 815 #define STABS_DEBUG \ 816 .stab 0 : { *(.stab) } \ 817 .stabstr 0 : { *(.stabstr) } \ 818 .stab.excl 0 : { *(.stab.excl) } \ 819 .stab.exclstr 0 : { *(.stab.exclstr) } \ 820 .stab.index 0 : { *(.stab.index) } \ 821 .stab.indexstr 0 : { *(.stab.indexstr) } 822 823 /* Required sections not related to debugging. */ 824 #define ELF_DETAILS \ 825 .comment 0 : { *(.comment) } \ 826 .symtab 0 : { *(.symtab) } \ 827 .strtab 0 : { *(.strtab) } \ 828 .shstrtab 0 : { *(.shstrtab) } 829 830 #ifdef CONFIG_GENERIC_BUG 831 #define BUG_TABLE \ 832 . = ALIGN(8); \ 833 __bug_table : AT(ADDR(__bug_table) - LOAD_OFFSET) { \ 834 BOUNDED_SECTION_BY(__bug_table, ___bug_table) \ 835 } 836 #else 837 #define BUG_TABLE 838 #endif 839 840 #ifdef CONFIG_UNWINDER_ORC 841 #define ORC_UNWIND_TABLE \ 842 . = ALIGN(4); \ 843 .orc_unwind_ip : AT(ADDR(.orc_unwind_ip) - LOAD_OFFSET) { \ 844 BOUNDED_SECTION_BY(.orc_unwind_ip, _orc_unwind_ip) \ 845 } \ 846 . = ALIGN(2); \ 847 .orc_unwind : AT(ADDR(.orc_unwind) - LOAD_OFFSET) { \ 848 BOUNDED_SECTION_BY(.orc_unwind, _orc_unwind) \ 849 } \ 850 text_size = _etext - _stext; \ 851 . = ALIGN(4); \ 852 .orc_lookup : AT(ADDR(.orc_lookup) - LOAD_OFFSET) { \ 853 orc_lookup = .; \ 854 . += (((text_size + LOOKUP_BLOCK_SIZE - 1) / \ 855 LOOKUP_BLOCK_SIZE) + 1) * 4; \ 856 orc_lookup_end = .; \ 857 } 858 #else 859 #define ORC_UNWIND_TABLE 860 #endif 861 862 /* Built-in firmware blobs */ 863 #ifdef CONFIG_FW_LOADER 864 #define FW_LOADER_BUILT_IN_DATA \ 865 .builtin_fw : AT(ADDR(.builtin_fw) - LOAD_OFFSET) ALIGN(8) { \ 866 BOUNDED_SECTION_PRE_LABEL(.builtin_fw, _builtin_fw, __start, __end) \ 867 } 868 #else 869 #define FW_LOADER_BUILT_IN_DATA 870 #endif 871 872 #ifdef CONFIG_PM_TRACE 873 #define TRACEDATA \ 874 . = ALIGN(4); \ 875 .tracedata : AT(ADDR(.tracedata) - LOAD_OFFSET) { \ 876 BOUNDED_SECTION_POST_LABEL(.tracedata, __tracedata, _start, _end) \ 877 } 878 #else 879 #define TRACEDATA 880 #endif 881 882 #ifdef CONFIG_PRINTK_INDEX 883 #define PRINTK_INDEX \ 884 .printk_index : AT(ADDR(.printk_index) - LOAD_OFFSET) { \ 885 BOUNDED_SECTION_BY(.printk_index, _printk_index) \ 886 } 887 #else 888 #define PRINTK_INDEX 889 #endif 890 891 /* 892 * Discard .note.GNU-stack, which is emitted as PROGBITS by the compiler. 893 * Otherwise, the type of .notes section would become PROGBITS instead of NOTES. 894 * 895 * Also, discard .note.gnu.property, otherwise it forces the notes section to 896 * be 8-byte aligned which causes alignment mismatches with the kernel's custom 897 * 4-byte aligned notes. 898 */ 899 #define NOTES \ 900 /DISCARD/ : { \ 901 *(.note.GNU-stack) \ 902 *(.note.gnu.property) \ 903 } \ 904 .notes : AT(ADDR(.notes) - LOAD_OFFSET) { \ 905 BOUNDED_SECTION_BY(.note.*, _notes) \ 906 } NOTES_HEADERS \ 907 NOTES_HEADERS_RESTORE 908 909 #define INIT_SETUP(initsetup_align) \ 910 . = ALIGN(initsetup_align); \ 911 BOUNDED_SECTION_POST_LABEL(.init.setup, __setup, _start, _end) 912 913 #define INIT_CALLS_LEVEL(level) \ 914 __initcall##level##_start = .; \ 915 KEEP(*(.initcall##level##.init)) \ 916 KEEP(*(.initcall##level##s.init)) \ 917 918 #define INIT_CALLS \ 919 __initcall_start = .; \ 920 KEEP(*(.initcallearly.init)) \ 921 INIT_CALLS_LEVEL(0) \ 922 INIT_CALLS_LEVEL(1) \ 923 INIT_CALLS_LEVEL(2) \ 924 INIT_CALLS_LEVEL(3) \ 925 INIT_CALLS_LEVEL(4) \ 926 INIT_CALLS_LEVEL(5) \ 927 INIT_CALLS_LEVEL(rootfs) \ 928 INIT_CALLS_LEVEL(6) \ 929 INIT_CALLS_LEVEL(7) \ 930 __initcall_end = .; 931 932 #define CON_INITCALL \ 933 BOUNDED_SECTION_POST_LABEL(.con_initcall.init, __con_initcall, _start, _end) 934 935 /* Alignment must be consistent with (kunit_suite *) in include/kunit/test.h */ 936 #define KUNIT_TABLE() \ 937 . = ALIGN(8); \ 938 BOUNDED_SECTION_POST_LABEL(.kunit_test_suites, __kunit_suites, _start, _end) 939 940 #ifdef CONFIG_BLK_DEV_INITRD 941 #define INIT_RAM_FS \ 942 . = ALIGN(4); \ 943 __initramfs_start = .; \ 944 KEEP(*(.init.ramfs)) \ 945 . = ALIGN(8); \ 946 KEEP(*(.init.ramfs.info)) 947 #else 948 #define INIT_RAM_FS 949 #endif 950 951 /* 952 * Memory encryption operates on a page basis. Since we need to clear 953 * the memory encryption mask for this section, it needs to be aligned 954 * on a page boundary and be a page-size multiple in length. 955 * 956 * Note: We use a separate section so that only this section gets 957 * decrypted to avoid exposing more than we wish. 958 */ 959 #ifdef CONFIG_AMD_MEM_ENCRYPT 960 #define PERCPU_DECRYPTED_SECTION \ 961 . = ALIGN(PAGE_SIZE); \ 962 *(.data..percpu..decrypted) \ 963 . = ALIGN(PAGE_SIZE); 964 #else 965 #define PERCPU_DECRYPTED_SECTION 966 #endif 967 968 969 /* 970 * Default discarded sections. 971 * 972 * Some archs want to discard exit text/data at runtime rather than 973 * link time due to cross-section references such as alt instructions, 974 * bug table, eh_frame, etc. DISCARDS must be the last of output 975 * section definitions so that such archs put those in earlier section 976 * definitions. 977 */ 978 #ifdef RUNTIME_DISCARD_EXIT 979 #define EXIT_DISCARDS 980 #else 981 #define EXIT_DISCARDS \ 982 EXIT_TEXT \ 983 EXIT_DATA 984 #endif 985 986 /* 987 * Clang's -fprofile-arcs, -fsanitize=kernel-address, and 988 * -fsanitize=thread produce unwanted sections (.eh_frame 989 * and .init_array.*), but CONFIG_CONSTRUCTORS wants to 990 * keep any .init_array.* sections. 991 * https://bugs.llvm.org/show_bug.cgi?id=46478 992 */ 993 #ifdef CONFIG_UNWIND_TABLES 994 #define DISCARD_EH_FRAME 995 #else 996 #define DISCARD_EH_FRAME *(.eh_frame) 997 #endif 998 #if defined(CONFIG_GCOV_KERNEL) || defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KCSAN) 999 # ifdef CONFIG_CONSTRUCTORS 1000 # define SANITIZER_DISCARDS \ 1001 DISCARD_EH_FRAME 1002 # else 1003 # define SANITIZER_DISCARDS \ 1004 *(.init_array) *(.init_array.*) \ 1005 DISCARD_EH_FRAME 1006 # endif 1007 #else 1008 # define SANITIZER_DISCARDS 1009 #endif 1010 1011 #define COMMON_DISCARDS \ 1012 SANITIZER_DISCARDS \ 1013 PATCHABLE_DISCARDS \ 1014 *(.discard) \ 1015 *(.discard.*) \ 1016 *(.modinfo) \ 1017 /* ld.bfd warns about .gnu.version* even when not emitted */ \ 1018 *(.gnu.version*) \ 1019 1020 #define DISCARDS \ 1021 /DISCARD/ : { \ 1022 EXIT_DISCARDS \ 1023 EXIT_CALL \ 1024 COMMON_DISCARDS \ 1025 } 1026 1027 /** 1028 * PERCPU_INPUT - the percpu input sections 1029 * @cacheline: cacheline size 1030 * 1031 * The core percpu section names and core symbols which do not rely 1032 * directly upon load addresses. 1033 * 1034 * @cacheline is used to align subsections to avoid false cacheline 1035 * sharing between subsections for different purposes. 1036 */ 1037 #define PERCPU_INPUT(cacheline) \ 1038 __per_cpu_start = .; \ 1039 *(.data..percpu..first) \ 1040 . = ALIGN(PAGE_SIZE); \ 1041 *(.data..percpu..page_aligned) \ 1042 . = ALIGN(cacheline); \ 1043 *(.data..percpu..read_mostly) \ 1044 . = ALIGN(cacheline); \ 1045 *(.data..percpu) \ 1046 *(.data..percpu..shared_aligned) \ 1047 PERCPU_DECRYPTED_SECTION \ 1048 __per_cpu_end = .; 1049 1050 /** 1051 * PERCPU_VADDR - define output section for percpu area 1052 * @cacheline: cacheline size 1053 * @vaddr: explicit base address (optional) 1054 * @phdr: destination PHDR (optional) 1055 * 1056 * Macro which expands to output section for percpu area. 1057 * 1058 * @cacheline is used to align subsections to avoid false cacheline 1059 * sharing between subsections for different purposes. 1060 * 1061 * If @vaddr is not blank, it specifies explicit base address and all 1062 * percpu symbols will be offset from the given address. If blank, 1063 * @vaddr always equals @laddr + LOAD_OFFSET. 1064 * 1065 * @phdr defines the output PHDR to use if not blank. Be warned that 1066 * output PHDR is sticky. If @phdr is specified, the next output 1067 * section in the linker script will go there too. @phdr should have 1068 * a leading colon. 1069 * 1070 * Note that this macros defines __per_cpu_load as an absolute symbol. 1071 * If there is no need to put the percpu section at a predetermined 1072 * address, use PERCPU_SECTION. 1073 */ 1074 #define PERCPU_VADDR(cacheline, vaddr, phdr) \ 1075 __per_cpu_load = .; \ 1076 .data..percpu vaddr : AT(__per_cpu_load - LOAD_OFFSET) { \ 1077 PERCPU_INPUT(cacheline) \ 1078 } phdr \ 1079 . = __per_cpu_load + SIZEOF(.data..percpu); 1080 1081 /** 1082 * PERCPU_SECTION - define output section for percpu area, simple version 1083 * @cacheline: cacheline size 1084 * 1085 * Align to PAGE_SIZE and outputs output section for percpu area. This 1086 * macro doesn't manipulate @vaddr or @phdr and __per_cpu_load and 1087 * __per_cpu_start will be identical. 1088 * 1089 * This macro is equivalent to ALIGN(PAGE_SIZE); PERCPU_VADDR(@cacheline,,) 1090 * except that __per_cpu_load is defined as a relative symbol against 1091 * .data..percpu which is required for relocatable x86_32 configuration. 1092 */ 1093 #define PERCPU_SECTION(cacheline) \ 1094 . = ALIGN(PAGE_SIZE); \ 1095 .data..percpu : AT(ADDR(.data..percpu) - LOAD_OFFSET) { \ 1096 __per_cpu_load = .; \ 1097 PERCPU_INPUT(cacheline) \ 1098 } 1099 1100 1101 /* 1102 * Definition of the high level *_SECTION macros 1103 * They will fit only a subset of the architectures 1104 */ 1105 1106 1107 /* 1108 * Writeable data. 1109 * All sections are combined in a single .data section. 1110 * The sections following CONSTRUCTORS are arranged so their 1111 * typical alignment matches. 1112 * A cacheline is typical/always less than a PAGE_SIZE so 1113 * the sections that has this restriction (or similar) 1114 * is located before the ones requiring PAGE_SIZE alignment. 1115 * NOSAVE_DATA starts and ends with a PAGE_SIZE alignment which 1116 * matches the requirement of PAGE_ALIGNED_DATA. 1117 * 1118 * use 0 as page_align if page_aligned data is not used */ 1119 #define RW_DATA(cacheline, pagealigned, inittask) \ 1120 . = ALIGN(PAGE_SIZE); \ 1121 .data : AT(ADDR(.data) - LOAD_OFFSET) { \ 1122 INIT_TASK_DATA(inittask) \ 1123 NOSAVE_DATA \ 1124 PAGE_ALIGNED_DATA(pagealigned) \ 1125 CACHELINE_ALIGNED_DATA(cacheline) \ 1126 READ_MOSTLY_DATA(cacheline) \ 1127 DATA_DATA \ 1128 CONSTRUCTORS \ 1129 } \ 1130 BUG_TABLE \ 1131 1132 #define INIT_TEXT_SECTION(inittext_align) \ 1133 . = ALIGN(inittext_align); \ 1134 .init.text : AT(ADDR(.init.text) - LOAD_OFFSET) { \ 1135 _sinittext = .; \ 1136 INIT_TEXT \ 1137 _einittext = .; \ 1138 } 1139 1140 #define INIT_DATA_SECTION(initsetup_align) \ 1141 .init.data : AT(ADDR(.init.data) - LOAD_OFFSET) { \ 1142 INIT_DATA \ 1143 INIT_SETUP(initsetup_align) \ 1144 INIT_CALLS \ 1145 CON_INITCALL \ 1146 INIT_RAM_FS \ 1147 } 1148 1149 #define BSS_SECTION(sbss_align, bss_align, stop_align) \ 1150 . = ALIGN(sbss_align); \ 1151 __bss_start = .; \ 1152 SBSS(sbss_align) \ 1153 BSS(bss_align) \ 1154 . = ALIGN(stop_align); \ 1155 __bss_stop = .; 1156