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