1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * ld script for the x86 kernel 4 * 5 * Historic 32-bit version written by Martin Mares <mj@atrey.karlin.mff.cuni.cz> 6 * 7 * Modernisation, unification and other changes and fixes: 8 * Copyright (C) 2007-2009 Sam Ravnborg <sam@ravnborg.org> 9 * 10 * 11 * Don't define absolute symbols until and unless you know that symbol 12 * value is should remain constant even if kernel image is relocated 13 * at run time. Absolute symbols are not relocated. If symbol value should 14 * change if kernel is relocated, make the symbol section relative and 15 * put it inside the section definition. 16 */ 17 18#ifdef CONFIG_X86_32 19#define LOAD_OFFSET __PAGE_OFFSET 20#else 21#define LOAD_OFFSET __START_KERNEL_map 22#endif 23 24#include <asm-generic/vmlinux.lds.h> 25#include <asm/asm-offsets.h> 26#include <asm/thread_info.h> 27#include <asm/page_types.h> 28#include <asm/orc_lookup.h> 29#include <asm/cache.h> 30#include <asm/boot.h> 31 32#undef i386 /* in case the preprocessor is a 32bit one */ 33 34OUTPUT_FORMAT(CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT) 35 36#ifdef CONFIG_X86_32 37OUTPUT_ARCH(i386) 38ENTRY(phys_startup_32) 39jiffies = jiffies_64; 40#else 41OUTPUT_ARCH(i386:x86-64) 42ENTRY(phys_startup_64) 43jiffies_64 = jiffies; 44#endif 45 46#if defined(CONFIG_X86_64) 47/* 48 * On 64-bit, align RODATA to 2MB so we retain large page mappings for 49 * boundaries spanning kernel text, rodata and data sections. 50 * 51 * However, kernel identity mappings will have different RWX permissions 52 * to the pages mapping to text and to the pages padding (which are freed) the 53 * text section. Hence kernel identity mappings will be broken to smaller 54 * pages. For 64-bit, kernel text and kernel identity mappings are different, 55 * so we can enable protection checks as well as retain 2MB large page 56 * mappings for kernel text. 57 */ 58#define X64_ALIGN_RODATA_BEGIN . = ALIGN(HPAGE_SIZE); 59 60#define X64_ALIGN_RODATA_END \ 61 . = ALIGN(HPAGE_SIZE); \ 62 __end_rodata_hpage_align = .; 63 64#define ALIGN_ENTRY_TEXT_BEGIN . = ALIGN(PMD_SIZE); 65#define ALIGN_ENTRY_TEXT_END . = ALIGN(PMD_SIZE); 66 67#else 68 69#define X64_ALIGN_RODATA_BEGIN 70#define X64_ALIGN_RODATA_END 71 72#define ALIGN_ENTRY_TEXT_BEGIN 73#define ALIGN_ENTRY_TEXT_END 74 75#endif 76 77PHDRS { 78 text PT_LOAD FLAGS(5); /* R_E */ 79 data PT_LOAD FLAGS(6); /* RW_ */ 80#ifdef CONFIG_X86_64 81#ifdef CONFIG_SMP 82 percpu PT_LOAD FLAGS(6); /* RW_ */ 83#endif 84 init PT_LOAD FLAGS(7); /* RWE */ 85#endif 86 note PT_NOTE FLAGS(0); /* ___ */ 87} 88 89SECTIONS 90{ 91#ifdef CONFIG_X86_32 92 . = LOAD_OFFSET + LOAD_PHYSICAL_ADDR; 93 phys_startup_32 = ABSOLUTE(startup_32 - LOAD_OFFSET); 94#else 95 . = __START_KERNEL; 96 phys_startup_64 = ABSOLUTE(startup_64 - LOAD_OFFSET); 97#endif 98 99 /* Text and read-only data */ 100 .text : AT(ADDR(.text) - LOAD_OFFSET) { 101 _text = .; 102 _stext = .; 103 /* bootstrapping code */ 104 HEAD_TEXT 105 . = ALIGN(8); 106 TEXT_TEXT 107 SCHED_TEXT 108 CPUIDLE_TEXT 109 LOCK_TEXT 110 KPROBES_TEXT 111 ALIGN_ENTRY_TEXT_BEGIN 112 ENTRY_TEXT 113 IRQENTRY_TEXT 114 ALIGN_ENTRY_TEXT_END 115 SOFTIRQENTRY_TEXT 116 *(.fixup) 117 *(.gnu.warning) 118 119#ifdef CONFIG_X86_64 120 . = ALIGN(PAGE_SIZE); 121 _entry_trampoline = .; 122 *(.entry_trampoline) 123 . = ALIGN(PAGE_SIZE); 124 ASSERT(. - _entry_trampoline == PAGE_SIZE, "entry trampoline is too big"); 125#endif 126 127 /* End of text section */ 128 _etext = .; 129 } :text = 0x9090 130 131 NOTES :text :note 132 133 EXCEPTION_TABLE(16) :text = 0x9090 134 135 /* .text should occupy whole number of pages */ 136 . = ALIGN(PAGE_SIZE); 137 X64_ALIGN_RODATA_BEGIN 138 RO_DATA(PAGE_SIZE) 139 X64_ALIGN_RODATA_END 140 141 /* Data */ 142 .data : AT(ADDR(.data) - LOAD_OFFSET) { 143 /* Start of data section */ 144 _sdata = .; 145 146 /* init_task */ 147 INIT_TASK_DATA(THREAD_SIZE) 148 149#ifdef CONFIG_X86_32 150 /* 32 bit has nosave before _edata */ 151 NOSAVE_DATA 152#endif 153 154 PAGE_ALIGNED_DATA(PAGE_SIZE) 155 156 CACHELINE_ALIGNED_DATA(L1_CACHE_BYTES) 157 158 DATA_DATA 159 CONSTRUCTORS 160 161 /* rarely changed data like cpu maps */ 162 READ_MOSTLY_DATA(INTERNODE_CACHE_BYTES) 163 164 /* End of data section */ 165 _edata = .; 166 } :data 167 168 BUG_TABLE 169 170 ORC_UNWIND_TABLE 171 172 . = ALIGN(PAGE_SIZE); 173 __vvar_page = .; 174 175 .vvar : AT(ADDR(.vvar) - LOAD_OFFSET) { 176 /* work around gold bug 13023 */ 177 __vvar_beginning_hack = .; 178 179 /* Place all vvars at the offsets in asm/vvar.h. */ 180#define EMIT_VVAR(name, offset) \ 181 . = __vvar_beginning_hack + offset; \ 182 *(.vvar_ ## name) 183#define __VVAR_KERNEL_LDS 184#include <asm/vvar.h> 185#undef __VVAR_KERNEL_LDS 186#undef EMIT_VVAR 187 188 /* 189 * Pad the rest of the page with zeros. Otherwise the loader 190 * can leave garbage here. 191 */ 192 . = __vvar_beginning_hack + PAGE_SIZE; 193 } :data 194 195 . = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE); 196 197 /* Init code and data - will be freed after init */ 198 . = ALIGN(PAGE_SIZE); 199 .init.begin : AT(ADDR(.init.begin) - LOAD_OFFSET) { 200 __init_begin = .; /* paired with __init_end */ 201 } 202 203#if defined(CONFIG_X86_64) && defined(CONFIG_SMP) 204 /* 205 * percpu offsets are zero-based on SMP. PERCPU_VADDR() changes the 206 * output PHDR, so the next output section - .init.text - should 207 * start another segment - init. 208 */ 209 PERCPU_VADDR(INTERNODE_CACHE_BYTES, 0, :percpu) 210 ASSERT(SIZEOF(.data..percpu) < CONFIG_PHYSICAL_START, 211 "per-CPU data too large - increase CONFIG_PHYSICAL_START") 212#endif 213 214 INIT_TEXT_SECTION(PAGE_SIZE) 215#ifdef CONFIG_X86_64 216 :init 217#endif 218 219 /* 220 * Section for code used exclusively before alternatives are run. All 221 * references to such code must be patched out by alternatives, normally 222 * by using X86_FEATURE_ALWAYS CPU feature bit. 223 * 224 * See static_cpu_has() for an example. 225 */ 226 .altinstr_aux : AT(ADDR(.altinstr_aux) - LOAD_OFFSET) { 227 *(.altinstr_aux) 228 } 229 230 INIT_DATA_SECTION(16) 231 232 .x86_cpu_dev.init : AT(ADDR(.x86_cpu_dev.init) - LOAD_OFFSET) { 233 __x86_cpu_dev_start = .; 234 *(.x86_cpu_dev.init) 235 __x86_cpu_dev_end = .; 236 } 237 238#ifdef CONFIG_X86_INTEL_MID 239 .x86_intel_mid_dev.init : AT(ADDR(.x86_intel_mid_dev.init) - \ 240 LOAD_OFFSET) { 241 __x86_intel_mid_dev_start = .; 242 *(.x86_intel_mid_dev.init) 243 __x86_intel_mid_dev_end = .; 244 } 245#endif 246 247 /* 248 * start address and size of operations which during runtime 249 * can be patched with virtualization friendly instructions or 250 * baremetal native ones. Think page table operations. 251 * Details in paravirt_types.h 252 */ 253 . = ALIGN(8); 254 .parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) { 255 __parainstructions = .; 256 *(.parainstructions) 257 __parainstructions_end = .; 258 } 259 260 /* 261 * struct alt_inst entries. From the header (alternative.h): 262 * "Alternative instructions for different CPU types or capabilities" 263 * Think locking instructions on spinlocks. 264 */ 265 . = ALIGN(8); 266 .altinstructions : AT(ADDR(.altinstructions) - LOAD_OFFSET) { 267 __alt_instructions = .; 268 *(.altinstructions) 269 __alt_instructions_end = .; 270 } 271 272 /* 273 * And here are the replacement instructions. The linker sticks 274 * them as binary blobs. The .altinstructions has enough data to 275 * get the address and the length of them to patch the kernel safely. 276 */ 277 .altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) { 278 *(.altinstr_replacement) 279 } 280 281 /* 282 * struct iommu_table_entry entries are injected in this section. 283 * It is an array of IOMMUs which during run time gets sorted depending 284 * on its dependency order. After rootfs_initcall is complete 285 * this section can be safely removed. 286 */ 287 .iommu_table : AT(ADDR(.iommu_table) - LOAD_OFFSET) { 288 __iommu_table = .; 289 *(.iommu_table) 290 __iommu_table_end = .; 291 } 292 293 . = ALIGN(8); 294 .apicdrivers : AT(ADDR(.apicdrivers) - LOAD_OFFSET) { 295 __apicdrivers = .; 296 *(.apicdrivers); 297 __apicdrivers_end = .; 298 } 299 300 . = ALIGN(8); 301 /* 302 * .exit.text is discard at runtime, not link time, to deal with 303 * references from .altinstructions and .eh_frame 304 */ 305 .exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) { 306 EXIT_TEXT 307 } 308 309 .exit.data : AT(ADDR(.exit.data) - LOAD_OFFSET) { 310 EXIT_DATA 311 } 312 313#if !defined(CONFIG_X86_64) || !defined(CONFIG_SMP) 314 PERCPU_SECTION(INTERNODE_CACHE_BYTES) 315#endif 316 317 . = ALIGN(PAGE_SIZE); 318 319 /* freed after init ends here */ 320 .init.end : AT(ADDR(.init.end) - LOAD_OFFSET) { 321 __init_end = .; 322 } 323 324 /* 325 * smp_locks might be freed after init 326 * start/end must be page aligned 327 */ 328 . = ALIGN(PAGE_SIZE); 329 .smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) { 330 __smp_locks = .; 331 *(.smp_locks) 332 . = ALIGN(PAGE_SIZE); 333 __smp_locks_end = .; 334 } 335 336#ifdef CONFIG_X86_64 337 .data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) { 338 NOSAVE_DATA 339 } 340#endif 341 342 /* BSS */ 343 . = ALIGN(PAGE_SIZE); 344 .bss : AT(ADDR(.bss) - LOAD_OFFSET) { 345 __bss_start = .; 346 *(.bss..page_aligned) 347 *(.bss) 348 . = ALIGN(PAGE_SIZE); 349 __bss_stop = .; 350 } 351 352 . = ALIGN(PAGE_SIZE); 353 .brk : AT(ADDR(.brk) - LOAD_OFFSET) { 354 __brk_base = .; 355 . += 64 * 1024; /* 64k alignment slop space */ 356 *(.brk_reservation) /* areas brk users have reserved */ 357 __brk_limit = .; 358 } 359 360 . = ALIGN(PAGE_SIZE); /* keep VO_INIT_SIZE page aligned */ 361 _end = .; 362 363 STABS_DEBUG 364 DWARF_DEBUG 365 366 /* Sections to be discarded */ 367 DISCARDS 368 /DISCARD/ : { 369 *(.eh_frame) 370 } 371} 372 373 374#ifdef CONFIG_X86_32 375/* 376 * The ASSERT() sink to . is intentional, for binutils 2.14 compatibility: 377 */ 378. = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE), 379 "kernel image bigger than KERNEL_IMAGE_SIZE"); 380#else 381/* 382 * Per-cpu symbols which need to be offset from __per_cpu_load 383 * for the boot processor. 384 */ 385#define INIT_PER_CPU(x) init_per_cpu__##x = x + __per_cpu_load 386INIT_PER_CPU(gdt_page); 387INIT_PER_CPU(irq_stack_union); 388 389/* 390 * Build-time check on the image size: 391 */ 392. = ASSERT((_end - _text <= KERNEL_IMAGE_SIZE), 393 "kernel image bigger than KERNEL_IMAGE_SIZE"); 394 395#ifdef CONFIG_SMP 396. = ASSERT((irq_stack_union == 0), 397 "irq_stack_union is not at start of per-cpu area"); 398#endif 399 400#endif /* CONFIG_X86_32 */ 401 402#ifdef CONFIG_KEXEC_CORE 403#include <asm/kexec.h> 404 405. = ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE, 406 "kexec control code size is too big"); 407#endif 408 409