1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/init/main.c 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 * 7 * GK 2/5/95 - Changed to support mounting root fs via NFS 8 * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96 9 * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96 10 * Simplified starting of init: Michael A. Griffith <grif@acm.org> 11 */ 12 13 #define DEBUG /* Enable initcall_debug */ 14 15 #include <linux/types.h> 16 #include <linux/extable.h> 17 #include <linux/module.h> 18 #include <linux/proc_fs.h> 19 #include <linux/binfmts.h> 20 #include <linux/kernel.h> 21 #include <linux/syscalls.h> 22 #include <linux/stackprotector.h> 23 #include <linux/string.h> 24 #include <linux/ctype.h> 25 #include <linux/delay.h> 26 #include <linux/ioport.h> 27 #include <linux/init.h> 28 #include <linux/initrd.h> 29 #include <linux/memblock.h> 30 #include <linux/acpi.h> 31 #include <linux/bootconfig.h> 32 #include <linux/console.h> 33 #include <linux/nmi.h> 34 #include <linux/percpu.h> 35 #include <linux/kmod.h> 36 #include <linux/vmalloc.h> 37 #include <linux/kernel_stat.h> 38 #include <linux/start_kernel.h> 39 #include <linux/security.h> 40 #include <linux/smp.h> 41 #include <linux/profile.h> 42 #include <linux/rcupdate.h> 43 #include <linux/moduleparam.h> 44 #include <linux/kallsyms.h> 45 #include <linux/writeback.h> 46 #include <linux/cpu.h> 47 #include <linux/cpuset.h> 48 #include <linux/cgroup.h> 49 #include <linux/efi.h> 50 #include <linux/tick.h> 51 #include <linux/sched/isolation.h> 52 #include <linux/interrupt.h> 53 #include <linux/taskstats_kern.h> 54 #include <linux/delayacct.h> 55 #include <linux/unistd.h> 56 #include <linux/utsname.h> 57 #include <linux/rmap.h> 58 #include <linux/mempolicy.h> 59 #include <linux/key.h> 60 #include <linux/buffer_head.h> 61 #include <linux/page_ext.h> 62 #include <linux/debug_locks.h> 63 #include <linux/debugobjects.h> 64 #include <linux/lockdep.h> 65 #include <linux/kmemleak.h> 66 #include <linux/pid_namespace.h> 67 #include <linux/device.h> 68 #include <linux/kthread.h> 69 #include <linux/sched.h> 70 #include <linux/sched/init.h> 71 #include <linux/signal.h> 72 #include <linux/idr.h> 73 #include <linux/kgdb.h> 74 #include <linux/ftrace.h> 75 #include <linux/async.h> 76 #include <linux/sfi.h> 77 #include <linux/shmem_fs.h> 78 #include <linux/slab.h> 79 #include <linux/perf_event.h> 80 #include <linux/ptrace.h> 81 #include <linux/pti.h> 82 #include <linux/blkdev.h> 83 #include <linux/elevator.h> 84 #include <linux/sched/clock.h> 85 #include <linux/sched/task.h> 86 #include <linux/sched/task_stack.h> 87 #include <linux/context_tracking.h> 88 #include <linux/random.h> 89 #include <linux/list.h> 90 #include <linux/integrity.h> 91 #include <linux/proc_ns.h> 92 #include <linux/io.h> 93 #include <linux/cache.h> 94 #include <linux/rodata_test.h> 95 #include <linux/jump_label.h> 96 #include <linux/mem_encrypt.h> 97 98 #include <asm/io.h> 99 #include <asm/bugs.h> 100 #include <asm/setup.h> 101 #include <asm/sections.h> 102 #include <asm/cacheflush.h> 103 104 #define CREATE_TRACE_POINTS 105 #include <trace/events/initcall.h> 106 107 static int kernel_init(void *); 108 109 extern void init_IRQ(void); 110 extern void radix_tree_init(void); 111 112 /* 113 * Debug helper: via this flag we know that we are in 'early bootup code' 114 * where only the boot processor is running with IRQ disabled. This means 115 * two things - IRQ must not be enabled before the flag is cleared and some 116 * operations which are not allowed with IRQ disabled are allowed while the 117 * flag is set. 118 */ 119 bool early_boot_irqs_disabled __read_mostly; 120 121 enum system_states system_state __read_mostly; 122 EXPORT_SYMBOL(system_state); 123 124 /* 125 * Boot command-line arguments 126 */ 127 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT 128 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT 129 130 extern void time_init(void); 131 /* Default late time init is NULL. archs can override this later. */ 132 void (*__initdata late_time_init)(void); 133 134 /* Untouched command line saved by arch-specific code. */ 135 char __initdata boot_command_line[COMMAND_LINE_SIZE]; 136 /* Untouched saved command line (eg. for /proc) */ 137 char *saved_command_line; 138 /* Command line for parameter parsing */ 139 static char *static_command_line; 140 /* Untouched extra command line */ 141 static char *extra_command_line; 142 /* Extra init arguments */ 143 static char *extra_init_args; 144 145 static char *execute_command; 146 static char *ramdisk_execute_command; 147 148 /* 149 * Used to generate warnings if static_key manipulation functions are used 150 * before jump_label_init is called. 151 */ 152 bool static_key_initialized __read_mostly; 153 EXPORT_SYMBOL_GPL(static_key_initialized); 154 155 /* 156 * If set, this is an indication to the drivers that reset the underlying 157 * device before going ahead with the initialization otherwise driver might 158 * rely on the BIOS and skip the reset operation. 159 * 160 * This is useful if kernel is booting in an unreliable environment. 161 * For ex. kdump situation where previous kernel has crashed, BIOS has been 162 * skipped and devices will be in unknown state. 163 */ 164 unsigned int reset_devices; 165 EXPORT_SYMBOL(reset_devices); 166 167 static int __init set_reset_devices(char *str) 168 { 169 reset_devices = 1; 170 return 1; 171 } 172 173 __setup("reset_devices", set_reset_devices); 174 175 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; 176 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; 177 static const char *panic_later, *panic_param; 178 179 extern const struct obs_kernel_param __setup_start[], __setup_end[]; 180 181 static bool __init obsolete_checksetup(char *line) 182 { 183 const struct obs_kernel_param *p; 184 bool had_early_param = false; 185 186 p = __setup_start; 187 do { 188 int n = strlen(p->str); 189 if (parameqn(line, p->str, n)) { 190 if (p->early) { 191 /* Already done in parse_early_param? 192 * (Needs exact match on param part). 193 * Keep iterating, as we can have early 194 * params and __setups of same names 8( */ 195 if (line[n] == '\0' || line[n] == '=') 196 had_early_param = true; 197 } else if (!p->setup_func) { 198 pr_warn("Parameter %s is obsolete, ignored\n", 199 p->str); 200 return true; 201 } else if (p->setup_func(line + n)) 202 return true; 203 } 204 p++; 205 } while (p < __setup_end); 206 207 return had_early_param; 208 } 209 210 /* 211 * This should be approx 2 Bo*oMips to start (note initial shift), and will 212 * still work even if initially too large, it will just take slightly longer 213 */ 214 unsigned long loops_per_jiffy = (1<<12); 215 EXPORT_SYMBOL(loops_per_jiffy); 216 217 static int __init debug_kernel(char *str) 218 { 219 console_loglevel = CONSOLE_LOGLEVEL_DEBUG; 220 return 0; 221 } 222 223 static int __init quiet_kernel(char *str) 224 { 225 console_loglevel = CONSOLE_LOGLEVEL_QUIET; 226 return 0; 227 } 228 229 early_param("debug", debug_kernel); 230 early_param("quiet", quiet_kernel); 231 232 static int __init loglevel(char *str) 233 { 234 int newlevel; 235 236 /* 237 * Only update loglevel value when a correct setting was passed, 238 * to prevent blind crashes (when loglevel being set to 0) that 239 * are quite hard to debug 240 */ 241 if (get_option(&str, &newlevel)) { 242 console_loglevel = newlevel; 243 return 0; 244 } 245 246 return -EINVAL; 247 } 248 249 early_param("loglevel", loglevel); 250 251 #ifdef CONFIG_BOOT_CONFIG 252 253 char xbc_namebuf[XBC_KEYLEN_MAX] __initdata; 254 255 #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0) 256 257 static int __init xbc_snprint_cmdline(char *buf, size_t size, 258 struct xbc_node *root) 259 { 260 struct xbc_node *knode, *vnode; 261 char *end = buf + size; 262 char c = '\"'; 263 const char *val; 264 int ret; 265 266 xbc_node_for_each_key_value(root, knode, val) { 267 ret = xbc_node_compose_key_after(root, knode, 268 xbc_namebuf, XBC_KEYLEN_MAX); 269 if (ret < 0) 270 return ret; 271 272 vnode = xbc_node_get_child(knode); 273 ret = snprintf(buf, rest(buf, end), "%s%c", xbc_namebuf, 274 vnode ? '=' : ' '); 275 if (ret < 0) 276 return ret; 277 buf += ret; 278 if (!vnode) 279 continue; 280 281 c = '\"'; 282 xbc_array_for_each_value(vnode, val) { 283 ret = snprintf(buf, rest(buf, end), "%c%s", c, val); 284 if (ret < 0) 285 return ret; 286 buf += ret; 287 c = ','; 288 } 289 if (rest(buf, end) > 2) 290 strcpy(buf, "\" "); 291 buf += 2; 292 } 293 294 return buf - (end - size); 295 } 296 #undef rest 297 298 /* Make an extra command line under given key word */ 299 static char * __init xbc_make_cmdline(const char *key) 300 { 301 struct xbc_node *root; 302 char *new_cmdline; 303 int ret, len = 0; 304 305 root = xbc_find_node(key); 306 if (!root) 307 return NULL; 308 309 /* Count required buffer size */ 310 len = xbc_snprint_cmdline(NULL, 0, root); 311 if (len <= 0) 312 return NULL; 313 314 new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES); 315 if (!new_cmdline) { 316 pr_err("Failed to allocate memory for extra kernel cmdline.\n"); 317 return NULL; 318 } 319 320 ret = xbc_snprint_cmdline(new_cmdline, len + 1, root); 321 if (ret < 0 || ret > len) { 322 pr_err("Failed to print extra kernel cmdline.\n"); 323 return NULL; 324 } 325 326 return new_cmdline; 327 } 328 329 u32 boot_config_checksum(unsigned char *p, u32 size) 330 { 331 u32 ret = 0; 332 333 while (size--) 334 ret += *p++; 335 336 return ret; 337 } 338 339 static void __init setup_boot_config(void) 340 { 341 u32 size, csum; 342 char *data, *copy; 343 u32 *hdr; 344 345 if (!initrd_end) 346 return; 347 348 hdr = (u32 *)(initrd_end - 8); 349 size = hdr[0]; 350 csum = hdr[1]; 351 352 if (size >= XBC_DATA_MAX) 353 return; 354 355 data = ((void *)hdr) - size; 356 if ((unsigned long)data < initrd_start) 357 return; 358 359 if (boot_config_checksum((unsigned char *)data, size) != csum) 360 return; 361 362 copy = memblock_alloc(size + 1, SMP_CACHE_BYTES); 363 if (!copy) { 364 pr_err("Failed to allocate memory for boot config\n"); 365 return; 366 } 367 368 memcpy(copy, data, size); 369 copy[size] = '\0'; 370 371 if (xbc_init(copy) < 0) 372 pr_err("Failed to parse boot config\n"); 373 else { 374 pr_info("Load boot config: %d bytes\n", size); 375 /* keys starting with "kernel." are passed via cmdline */ 376 extra_command_line = xbc_make_cmdline("kernel"); 377 /* Also, "init." keys are init arguments */ 378 extra_init_args = xbc_make_cmdline("init"); 379 } 380 } 381 #else 382 #define setup_boot_config() do { } while (0) 383 #endif 384 385 /* Change NUL term back to "=", to make "param" the whole string. */ 386 static int __init repair_env_string(char *param, char *val, 387 const char *unused, void *arg) 388 { 389 if (val) { 390 /* param=val or param="val"? */ 391 if (val == param+strlen(param)+1) 392 val[-1] = '='; 393 else if (val == param+strlen(param)+2) { 394 val[-2] = '='; 395 memmove(val-1, val, strlen(val)+1); 396 val--; 397 } else 398 BUG(); 399 } 400 return 0; 401 } 402 403 /* Anything after -- gets handed straight to init. */ 404 static int __init set_init_arg(char *param, char *val, 405 const char *unused, void *arg) 406 { 407 unsigned int i; 408 409 if (panic_later) 410 return 0; 411 412 repair_env_string(param, val, unused, NULL); 413 414 for (i = 0; argv_init[i]; i++) { 415 if (i == MAX_INIT_ARGS) { 416 panic_later = "init"; 417 panic_param = param; 418 return 0; 419 } 420 } 421 argv_init[i] = param; 422 return 0; 423 } 424 425 /* 426 * Unknown boot options get handed to init, unless they look like 427 * unused parameters (modprobe will find them in /proc/cmdline). 428 */ 429 static int __init unknown_bootoption(char *param, char *val, 430 const char *unused, void *arg) 431 { 432 repair_env_string(param, val, unused, NULL); 433 434 /* Handle obsolete-style parameters */ 435 if (obsolete_checksetup(param)) 436 return 0; 437 438 /* Unused module parameter. */ 439 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) 440 return 0; 441 442 if (panic_later) 443 return 0; 444 445 if (val) { 446 /* Environment option */ 447 unsigned int i; 448 for (i = 0; envp_init[i]; i++) { 449 if (i == MAX_INIT_ENVS) { 450 panic_later = "env"; 451 panic_param = param; 452 } 453 if (!strncmp(param, envp_init[i], val - param)) 454 break; 455 } 456 envp_init[i] = param; 457 } else { 458 /* Command line option */ 459 unsigned int i; 460 for (i = 0; argv_init[i]; i++) { 461 if (i == MAX_INIT_ARGS) { 462 panic_later = "init"; 463 panic_param = param; 464 } 465 } 466 argv_init[i] = param; 467 } 468 return 0; 469 } 470 471 static int __init init_setup(char *str) 472 { 473 unsigned int i; 474 475 execute_command = str; 476 /* 477 * In case LILO is going to boot us with default command line, 478 * it prepends "auto" before the whole cmdline which makes 479 * the shell think it should execute a script with such name. 480 * So we ignore all arguments entered _before_ init=... [MJ] 481 */ 482 for (i = 1; i < MAX_INIT_ARGS; i++) 483 argv_init[i] = NULL; 484 return 1; 485 } 486 __setup("init=", init_setup); 487 488 static int __init rdinit_setup(char *str) 489 { 490 unsigned int i; 491 492 ramdisk_execute_command = str; 493 /* See "auto" comment in init_setup */ 494 for (i = 1; i < MAX_INIT_ARGS; i++) 495 argv_init[i] = NULL; 496 return 1; 497 } 498 __setup("rdinit=", rdinit_setup); 499 500 #ifndef CONFIG_SMP 501 static const unsigned int setup_max_cpus = NR_CPUS; 502 static inline void setup_nr_cpu_ids(void) { } 503 static inline void smp_prepare_cpus(unsigned int maxcpus) { } 504 #endif 505 506 /* 507 * We need to store the untouched command line for future reference. 508 * We also need to store the touched command line since the parameter 509 * parsing is performed in place, and we should allow a component to 510 * store reference of name/value for future reference. 511 */ 512 static void __init setup_command_line(char *command_line) 513 { 514 size_t len, xlen = 0, ilen = 0; 515 516 if (extra_command_line) 517 xlen = strlen(extra_command_line); 518 if (extra_init_args) 519 ilen = strlen(extra_init_args) + 4; /* for " -- " */ 520 521 len = xlen + strlen(boot_command_line) + 1; 522 523 saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES); 524 if (!saved_command_line) 525 panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen); 526 527 static_command_line = memblock_alloc(len, SMP_CACHE_BYTES); 528 if (!static_command_line) 529 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 530 531 if (xlen) { 532 /* 533 * We have to put extra_command_line before boot command 534 * lines because there could be dashes (separator of init 535 * command line) in the command lines. 536 */ 537 strcpy(saved_command_line, extra_command_line); 538 strcpy(static_command_line, extra_command_line); 539 } 540 strcpy(saved_command_line + xlen, boot_command_line); 541 strcpy(static_command_line + xlen, command_line); 542 543 if (ilen) { 544 /* 545 * Append supplemental init boot args to saved_command_line 546 * so that user can check what command line options passed 547 * to init. 548 */ 549 len = strlen(saved_command_line); 550 if (!strstr(boot_command_line, " -- ")) { 551 strcpy(saved_command_line + len, " -- "); 552 len += 4; 553 } else 554 saved_command_line[len++] = ' '; 555 556 strcpy(saved_command_line + len, extra_init_args); 557 } 558 } 559 560 /* 561 * We need to finalize in a non-__init function or else race conditions 562 * between the root thread and the init thread may cause start_kernel to 563 * be reaped by free_initmem before the root thread has proceeded to 564 * cpu_idle. 565 * 566 * gcc-3.4 accidentally inlines this function, so use noinline. 567 */ 568 569 static __initdata DECLARE_COMPLETION(kthreadd_done); 570 571 noinline void __ref rest_init(void) 572 { 573 struct task_struct *tsk; 574 int pid; 575 576 rcu_scheduler_starting(); 577 /* 578 * We need to spawn init first so that it obtains pid 1, however 579 * the init task will end up wanting to create kthreads, which, if 580 * we schedule it before we create kthreadd, will OOPS. 581 */ 582 pid = kernel_thread(kernel_init, NULL, CLONE_FS); 583 /* 584 * Pin init on the boot CPU. Task migration is not properly working 585 * until sched_init_smp() has been run. It will set the allowed 586 * CPUs for init to the non isolated CPUs. 587 */ 588 rcu_read_lock(); 589 tsk = find_task_by_pid_ns(pid, &init_pid_ns); 590 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); 591 rcu_read_unlock(); 592 593 numa_default_policy(); 594 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES); 595 rcu_read_lock(); 596 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 597 rcu_read_unlock(); 598 599 /* 600 * Enable might_sleep() and smp_processor_id() checks. 601 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y 602 * kernel_thread() would trigger might_sleep() splats. With 603 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled 604 * already, but it's stuck on the kthreadd_done completion. 605 */ 606 system_state = SYSTEM_SCHEDULING; 607 608 complete(&kthreadd_done); 609 610 /* 611 * The boot idle thread must execute schedule() 612 * at least once to get things moving: 613 */ 614 schedule_preempt_disabled(); 615 /* Call into cpu_idle with preempt disabled */ 616 cpu_startup_entry(CPUHP_ONLINE); 617 } 618 619 /* Check for early params. */ 620 static int __init do_early_param(char *param, char *val, 621 const char *unused, void *arg) 622 { 623 const struct obs_kernel_param *p; 624 625 for (p = __setup_start; p < __setup_end; p++) { 626 if ((p->early && parameq(param, p->str)) || 627 (strcmp(param, "console") == 0 && 628 strcmp(p->str, "earlycon") == 0) 629 ) { 630 if (p->setup_func(val) != 0) 631 pr_warn("Malformed early option '%s'\n", param); 632 } 633 } 634 /* We accept everything at this stage. */ 635 return 0; 636 } 637 638 void __init parse_early_options(char *cmdline) 639 { 640 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL, 641 do_early_param); 642 } 643 644 /* Arch code calls this early on, or if not, just before other parsing. */ 645 void __init parse_early_param(void) 646 { 647 static int done __initdata; 648 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; 649 650 if (done) 651 return; 652 653 /* All fall through to do_early_param. */ 654 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 655 parse_early_options(tmp_cmdline); 656 done = 1; 657 } 658 659 void __init __weak arch_post_acpi_subsys_init(void) { } 660 661 void __init __weak smp_setup_processor_id(void) 662 { 663 } 664 665 # if THREAD_SIZE >= PAGE_SIZE 666 void __init __weak thread_stack_cache_init(void) 667 { 668 } 669 #endif 670 671 void __init __weak mem_encrypt_init(void) { } 672 673 void __init __weak poking_init(void) { } 674 675 void __init __weak pgtable_cache_init(void) { } 676 677 bool initcall_debug; 678 core_param(initcall_debug, initcall_debug, bool, 0644); 679 680 #ifdef TRACEPOINTS_ENABLED 681 static void __init initcall_debug_enable(void); 682 #else 683 static inline void initcall_debug_enable(void) 684 { 685 } 686 #endif 687 688 /* Report memory auto-initialization states for this boot. */ 689 static void __init report_meminit(void) 690 { 691 const char *stack; 692 693 if (IS_ENABLED(CONFIG_INIT_STACK_ALL)) 694 stack = "all"; 695 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL)) 696 stack = "byref_all"; 697 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF)) 698 stack = "byref"; 699 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER)) 700 stack = "__user"; 701 else 702 stack = "off"; 703 704 pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n", 705 stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off", 706 want_init_on_free() ? "on" : "off"); 707 if (want_init_on_free()) 708 pr_info("mem auto-init: clearing system memory may take some time...\n"); 709 } 710 711 /* 712 * Set up kernel memory allocators 713 */ 714 static void __init mm_init(void) 715 { 716 /* 717 * page_ext requires contiguous pages, 718 * bigger than MAX_ORDER unless SPARSEMEM. 719 */ 720 page_ext_init_flatmem(); 721 report_meminit(); 722 mem_init(); 723 kmem_cache_init(); 724 kmemleak_init(); 725 pgtable_init(); 726 debug_objects_mem_init(); 727 vmalloc_init(); 728 ioremap_huge_init(); 729 /* Should be run before the first non-init thread is created */ 730 init_espfix_bsp(); 731 /* Should be run after espfix64 is set up. */ 732 pti_init(); 733 } 734 735 void __init __weak arch_call_rest_init(void) 736 { 737 rest_init(); 738 } 739 740 asmlinkage __visible void __init start_kernel(void) 741 { 742 char *command_line; 743 char *after_dashes; 744 745 set_task_stack_end_magic(&init_task); 746 smp_setup_processor_id(); 747 debug_objects_early_init(); 748 749 cgroup_init_early(); 750 751 local_irq_disable(); 752 early_boot_irqs_disabled = true; 753 754 /* 755 * Interrupts are still disabled. Do necessary setups, then 756 * enable them. 757 */ 758 boot_cpu_init(); 759 page_address_init(); 760 pr_notice("%s", linux_banner); 761 early_security_init(); 762 setup_arch(&command_line); 763 setup_boot_config(); 764 setup_command_line(command_line); 765 setup_nr_cpu_ids(); 766 setup_per_cpu_areas(); 767 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 768 boot_cpu_hotplug_init(); 769 770 build_all_zonelists(NULL); 771 page_alloc_init(); 772 773 pr_notice("Kernel command line: %s\n", saved_command_line); 774 /* parameters may set static keys */ 775 jump_label_init(); 776 parse_early_param(); 777 after_dashes = parse_args("Booting kernel", 778 static_command_line, __start___param, 779 __stop___param - __start___param, 780 -1, -1, NULL, &unknown_bootoption); 781 if (!IS_ERR_OR_NULL(after_dashes)) 782 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1, 783 NULL, set_init_arg); 784 if (extra_init_args) 785 parse_args("Setting extra init args", extra_init_args, 786 NULL, 0, -1, -1, NULL, set_init_arg); 787 788 /* 789 * These use large bootmem allocations and must precede 790 * kmem_cache_init() 791 */ 792 setup_log_buf(0); 793 vfs_caches_init_early(); 794 sort_main_extable(); 795 trap_init(); 796 mm_init(); 797 798 ftrace_init(); 799 800 /* trace_printk can be enabled here */ 801 early_trace_init(); 802 803 /* 804 * Set up the scheduler prior starting any interrupts (such as the 805 * timer interrupt). Full topology setup happens at smp_init() 806 * time - but meanwhile we still have a functioning scheduler. 807 */ 808 sched_init(); 809 /* 810 * Disable preemption - early bootup scheduling is extremely 811 * fragile until we cpu_idle() for the first time. 812 */ 813 preempt_disable(); 814 if (WARN(!irqs_disabled(), 815 "Interrupts were enabled *very* early, fixing it\n")) 816 local_irq_disable(); 817 radix_tree_init(); 818 819 /* 820 * Set up housekeeping before setting up workqueues to allow the unbound 821 * workqueue to take non-housekeeping into account. 822 */ 823 housekeeping_init(); 824 825 /* 826 * Allow workqueue creation and work item queueing/cancelling 827 * early. Work item execution depends on kthreads and starts after 828 * workqueue_init(). 829 */ 830 workqueue_init_early(); 831 832 rcu_init(); 833 834 /* Trace events are available after this */ 835 trace_init(); 836 837 if (initcall_debug) 838 initcall_debug_enable(); 839 840 context_tracking_init(); 841 /* init some links before init_ISA_irqs() */ 842 early_irq_init(); 843 init_IRQ(); 844 tick_init(); 845 rcu_init_nohz(); 846 init_timers(); 847 hrtimers_init(); 848 softirq_init(); 849 timekeeping_init(); 850 851 /* 852 * For best initial stack canary entropy, prepare it after: 853 * - setup_arch() for any UEFI RNG entropy and boot cmdline access 854 * - timekeeping_init() for ktime entropy used in rand_initialize() 855 * - rand_initialize() to get any arch-specific entropy like RDRAND 856 * - add_latent_entropy() to get any latent entropy 857 * - adding command line entropy 858 */ 859 rand_initialize(); 860 add_latent_entropy(); 861 add_device_randomness(command_line, strlen(command_line)); 862 boot_init_stack_canary(); 863 864 time_init(); 865 printk_safe_init(); 866 perf_event_init(); 867 profile_init(); 868 call_function_init(); 869 WARN(!irqs_disabled(), "Interrupts were enabled early\n"); 870 871 early_boot_irqs_disabled = false; 872 local_irq_enable(); 873 874 kmem_cache_init_late(); 875 876 /* 877 * HACK ALERT! This is early. We're enabling the console before 878 * we've done PCI setups etc, and console_init() must be aware of 879 * this. But we do want output early, in case something goes wrong. 880 */ 881 console_init(); 882 if (panic_later) 883 panic("Too many boot %s vars at `%s'", panic_later, 884 panic_param); 885 886 lockdep_init(); 887 888 /* 889 * Need to run this when irqs are enabled, because it wants 890 * to self-test [hard/soft]-irqs on/off lock inversion bugs 891 * too: 892 */ 893 locking_selftest(); 894 895 /* 896 * This needs to be called before any devices perform DMA 897 * operations that might use the SWIOTLB bounce buffers. It will 898 * mark the bounce buffers as decrypted so that their usage will 899 * not cause "plain-text" data to be decrypted when accessed. 900 */ 901 mem_encrypt_init(); 902 903 #ifdef CONFIG_BLK_DEV_INITRD 904 if (initrd_start && !initrd_below_start_ok && 905 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 906 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n", 907 page_to_pfn(virt_to_page((void *)initrd_start)), 908 min_low_pfn); 909 initrd_start = 0; 910 } 911 #endif 912 setup_per_cpu_pageset(); 913 numa_policy_init(); 914 acpi_early_init(); 915 if (late_time_init) 916 late_time_init(); 917 sched_clock_init(); 918 calibrate_delay(); 919 pid_idr_init(); 920 anon_vma_init(); 921 #ifdef CONFIG_X86 922 if (efi_enabled(EFI_RUNTIME_SERVICES)) 923 efi_enter_virtual_mode(); 924 #endif 925 thread_stack_cache_init(); 926 cred_init(); 927 fork_init(); 928 proc_caches_init(); 929 uts_ns_init(); 930 buffer_init(); 931 key_init(); 932 security_init(); 933 dbg_late_init(); 934 vfs_caches_init(); 935 pagecache_init(); 936 signals_init(); 937 seq_file_init(); 938 proc_root_init(); 939 nsfs_init(); 940 cpuset_init(); 941 cgroup_init(); 942 taskstats_init_early(); 943 delayacct_init(); 944 945 poking_init(); 946 check_bugs(); 947 948 acpi_subsystem_init(); 949 arch_post_acpi_subsys_init(); 950 sfi_init_late(); 951 952 /* Do the rest non-__init'ed, we're now alive */ 953 arch_call_rest_init(); 954 } 955 956 /* Call all constructor functions linked into the kernel. */ 957 static void __init do_ctors(void) 958 { 959 #ifdef CONFIG_CONSTRUCTORS 960 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; 961 962 for (; fn < (ctor_fn_t *) __ctors_end; fn++) 963 (*fn)(); 964 #endif 965 } 966 967 #ifdef CONFIG_KALLSYMS 968 struct blacklist_entry { 969 struct list_head next; 970 char *buf; 971 }; 972 973 static __initdata_or_module LIST_HEAD(blacklisted_initcalls); 974 975 static int __init initcall_blacklist(char *str) 976 { 977 char *str_entry; 978 struct blacklist_entry *entry; 979 980 /* str argument is a comma-separated list of functions */ 981 do { 982 str_entry = strsep(&str, ","); 983 if (str_entry) { 984 pr_debug("blacklisting initcall %s\n", str_entry); 985 entry = memblock_alloc(sizeof(*entry), 986 SMP_CACHE_BYTES); 987 if (!entry) 988 panic("%s: Failed to allocate %zu bytes\n", 989 __func__, sizeof(*entry)); 990 entry->buf = memblock_alloc(strlen(str_entry) + 1, 991 SMP_CACHE_BYTES); 992 if (!entry->buf) 993 panic("%s: Failed to allocate %zu bytes\n", 994 __func__, strlen(str_entry) + 1); 995 strcpy(entry->buf, str_entry); 996 list_add(&entry->next, &blacklisted_initcalls); 997 } 998 } while (str_entry); 999 1000 return 0; 1001 } 1002 1003 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1004 { 1005 struct blacklist_entry *entry; 1006 char fn_name[KSYM_SYMBOL_LEN]; 1007 unsigned long addr; 1008 1009 if (list_empty(&blacklisted_initcalls)) 1010 return false; 1011 1012 addr = (unsigned long) dereference_function_descriptor(fn); 1013 sprint_symbol_no_offset(fn_name, addr); 1014 1015 /* 1016 * fn will be "function_name [module_name]" where [module_name] is not 1017 * displayed for built-in init functions. Strip off the [module_name]. 1018 */ 1019 strreplace(fn_name, ' ', '\0'); 1020 1021 list_for_each_entry(entry, &blacklisted_initcalls, next) { 1022 if (!strcmp(fn_name, entry->buf)) { 1023 pr_debug("initcall %s blacklisted\n", fn_name); 1024 return true; 1025 } 1026 } 1027 1028 return false; 1029 } 1030 #else 1031 static int __init initcall_blacklist(char *str) 1032 { 1033 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n"); 1034 return 0; 1035 } 1036 1037 static bool __init_or_module initcall_blacklisted(initcall_t fn) 1038 { 1039 return false; 1040 } 1041 #endif 1042 __setup("initcall_blacklist=", initcall_blacklist); 1043 1044 static __init_or_module void 1045 trace_initcall_start_cb(void *data, initcall_t fn) 1046 { 1047 ktime_t *calltime = (ktime_t *)data; 1048 1049 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current)); 1050 *calltime = ktime_get(); 1051 } 1052 1053 static __init_or_module void 1054 trace_initcall_finish_cb(void *data, initcall_t fn, int ret) 1055 { 1056 ktime_t *calltime = (ktime_t *)data; 1057 ktime_t delta, rettime; 1058 unsigned long long duration; 1059 1060 rettime = ktime_get(); 1061 delta = ktime_sub(rettime, *calltime); 1062 duration = (unsigned long long) ktime_to_ns(delta) >> 10; 1063 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n", 1064 fn, ret, duration); 1065 } 1066 1067 static ktime_t initcall_calltime; 1068 1069 #ifdef TRACEPOINTS_ENABLED 1070 static void __init initcall_debug_enable(void) 1071 { 1072 int ret; 1073 1074 ret = register_trace_initcall_start(trace_initcall_start_cb, 1075 &initcall_calltime); 1076 ret |= register_trace_initcall_finish(trace_initcall_finish_cb, 1077 &initcall_calltime); 1078 WARN(ret, "Failed to register initcall tracepoints\n"); 1079 } 1080 # define do_trace_initcall_start trace_initcall_start 1081 # define do_trace_initcall_finish trace_initcall_finish 1082 #else 1083 static inline void do_trace_initcall_start(initcall_t fn) 1084 { 1085 if (!initcall_debug) 1086 return; 1087 trace_initcall_start_cb(&initcall_calltime, fn); 1088 } 1089 static inline void do_trace_initcall_finish(initcall_t fn, int ret) 1090 { 1091 if (!initcall_debug) 1092 return; 1093 trace_initcall_finish_cb(&initcall_calltime, fn, ret); 1094 } 1095 #endif /* !TRACEPOINTS_ENABLED */ 1096 1097 int __init_or_module do_one_initcall(initcall_t fn) 1098 { 1099 int count = preempt_count(); 1100 char msgbuf[64]; 1101 int ret; 1102 1103 if (initcall_blacklisted(fn)) 1104 return -EPERM; 1105 1106 do_trace_initcall_start(fn); 1107 ret = fn(); 1108 do_trace_initcall_finish(fn, ret); 1109 1110 msgbuf[0] = 0; 1111 1112 if (preempt_count() != count) { 1113 sprintf(msgbuf, "preemption imbalance "); 1114 preempt_count_set(count); 1115 } 1116 if (irqs_disabled()) { 1117 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 1118 local_irq_enable(); 1119 } 1120 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf); 1121 1122 add_latent_entropy(); 1123 return ret; 1124 } 1125 1126 1127 extern initcall_entry_t __initcall_start[]; 1128 extern initcall_entry_t __initcall0_start[]; 1129 extern initcall_entry_t __initcall1_start[]; 1130 extern initcall_entry_t __initcall2_start[]; 1131 extern initcall_entry_t __initcall3_start[]; 1132 extern initcall_entry_t __initcall4_start[]; 1133 extern initcall_entry_t __initcall5_start[]; 1134 extern initcall_entry_t __initcall6_start[]; 1135 extern initcall_entry_t __initcall7_start[]; 1136 extern initcall_entry_t __initcall_end[]; 1137 1138 static initcall_entry_t *initcall_levels[] __initdata = { 1139 __initcall0_start, 1140 __initcall1_start, 1141 __initcall2_start, 1142 __initcall3_start, 1143 __initcall4_start, 1144 __initcall5_start, 1145 __initcall6_start, 1146 __initcall7_start, 1147 __initcall_end, 1148 }; 1149 1150 /* Keep these in sync with initcalls in include/linux/init.h */ 1151 static const char *initcall_level_names[] __initdata = { 1152 "pure", 1153 "core", 1154 "postcore", 1155 "arch", 1156 "subsys", 1157 "fs", 1158 "device", 1159 "late", 1160 }; 1161 1162 static void __init do_initcall_level(int level, char *command_line) 1163 { 1164 initcall_entry_t *fn; 1165 1166 parse_args(initcall_level_names[level], 1167 command_line, __start___param, 1168 __stop___param - __start___param, 1169 level, level, 1170 NULL, &repair_env_string); 1171 1172 trace_initcall_level(initcall_level_names[level]); 1173 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) 1174 do_one_initcall(initcall_from_entry(fn)); 1175 } 1176 1177 static void __init do_initcalls(void) 1178 { 1179 int level; 1180 size_t len = strlen(saved_command_line) + 1; 1181 char *command_line; 1182 1183 command_line = kzalloc(len, GFP_KERNEL); 1184 if (!command_line) 1185 panic("%s: Failed to allocate %zu bytes\n", __func__, len); 1186 1187 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) { 1188 /* Parser modifies command_line, restore it each time */ 1189 strcpy(command_line, saved_command_line); 1190 do_initcall_level(level, command_line); 1191 } 1192 1193 kfree(command_line); 1194 } 1195 1196 /* 1197 * Ok, the machine is now initialized. None of the devices 1198 * have been touched yet, but the CPU subsystem is up and 1199 * running, and memory and process management works. 1200 * 1201 * Now we can finally start doing some real work.. 1202 */ 1203 static void __init do_basic_setup(void) 1204 { 1205 cpuset_init_smp(); 1206 driver_init(); 1207 init_irq_proc(); 1208 do_ctors(); 1209 usermodehelper_enable(); 1210 do_initcalls(); 1211 } 1212 1213 static void __init do_pre_smp_initcalls(void) 1214 { 1215 initcall_entry_t *fn; 1216 1217 trace_initcall_level("early"); 1218 for (fn = __initcall_start; fn < __initcall0_start; fn++) 1219 do_one_initcall(initcall_from_entry(fn)); 1220 } 1221 1222 static int run_init_process(const char *init_filename) 1223 { 1224 argv_init[0] = init_filename; 1225 pr_info("Run %s as init process\n", init_filename); 1226 return do_execve(getname_kernel(init_filename), 1227 (const char __user *const __user *)argv_init, 1228 (const char __user *const __user *)envp_init); 1229 } 1230 1231 static int try_to_run_init_process(const char *init_filename) 1232 { 1233 int ret; 1234 1235 ret = run_init_process(init_filename); 1236 1237 if (ret && ret != -ENOENT) { 1238 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n", 1239 init_filename, ret); 1240 } 1241 1242 return ret; 1243 } 1244 1245 static noinline void __init kernel_init_freeable(void); 1246 1247 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) 1248 bool rodata_enabled __ro_after_init = true; 1249 static int __init set_debug_rodata(char *str) 1250 { 1251 return strtobool(str, &rodata_enabled); 1252 } 1253 __setup("rodata=", set_debug_rodata); 1254 #endif 1255 1256 #ifdef CONFIG_STRICT_KERNEL_RWX 1257 static void mark_readonly(void) 1258 { 1259 if (rodata_enabled) { 1260 /* 1261 * load_module() results in W+X mappings, which are cleaned 1262 * up with call_rcu(). Let's make sure that queued work is 1263 * flushed so that we don't hit false positives looking for 1264 * insecure pages which are W+X. 1265 */ 1266 rcu_barrier(); 1267 mark_rodata_ro(); 1268 rodata_test(); 1269 } else 1270 pr_info("Kernel memory protection disabled.\n"); 1271 } 1272 #else 1273 static inline void mark_readonly(void) 1274 { 1275 pr_warn("This architecture does not have kernel memory protection.\n"); 1276 } 1277 #endif 1278 1279 void __weak free_initmem(void) 1280 { 1281 free_initmem_default(POISON_FREE_INITMEM); 1282 } 1283 1284 static int __ref kernel_init(void *unused) 1285 { 1286 int ret; 1287 1288 kernel_init_freeable(); 1289 /* need to finish all async __init code before freeing the memory */ 1290 async_synchronize_full(); 1291 ftrace_free_init_mem(); 1292 free_initmem(); 1293 mark_readonly(); 1294 1295 /* 1296 * Kernel mappings are now finalized - update the userspace page-table 1297 * to finalize PTI. 1298 */ 1299 pti_finalize(); 1300 1301 system_state = SYSTEM_RUNNING; 1302 numa_default_policy(); 1303 1304 rcu_end_inkernel_boot(); 1305 1306 if (ramdisk_execute_command) { 1307 ret = run_init_process(ramdisk_execute_command); 1308 if (!ret) 1309 return 0; 1310 pr_err("Failed to execute %s (error %d)\n", 1311 ramdisk_execute_command, ret); 1312 } 1313 1314 /* 1315 * We try each of these until one succeeds. 1316 * 1317 * The Bourne shell can be used instead of init if we are 1318 * trying to recover a really broken machine. 1319 */ 1320 if (execute_command) { 1321 ret = run_init_process(execute_command); 1322 if (!ret) 1323 return 0; 1324 panic("Requested init %s failed (error %d).", 1325 execute_command, ret); 1326 } 1327 if (!try_to_run_init_process("/sbin/init") || 1328 !try_to_run_init_process("/etc/init") || 1329 !try_to_run_init_process("/bin/init") || 1330 !try_to_run_init_process("/bin/sh")) 1331 return 0; 1332 1333 panic("No working init found. Try passing init= option to kernel. " 1334 "See Linux Documentation/admin-guide/init.rst for guidance."); 1335 } 1336 1337 void console_on_rootfs(void) 1338 { 1339 /* Open the /dev/console as stdin, this should never fail */ 1340 if (ksys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0) 1341 pr_err("Warning: unable to open an initial console.\n"); 1342 1343 /* create stdout/stderr */ 1344 (void) ksys_dup(0); 1345 (void) ksys_dup(0); 1346 } 1347 1348 static noinline void __init kernel_init_freeable(void) 1349 { 1350 /* 1351 * Wait until kthreadd is all set-up. 1352 */ 1353 wait_for_completion(&kthreadd_done); 1354 1355 /* Now the scheduler is fully set up and can do blocking allocations */ 1356 gfp_allowed_mask = __GFP_BITS_MASK; 1357 1358 /* 1359 * init can allocate pages on any node 1360 */ 1361 set_mems_allowed(node_states[N_MEMORY]); 1362 1363 cad_pid = task_pid(current); 1364 1365 smp_prepare_cpus(setup_max_cpus); 1366 1367 workqueue_init(); 1368 1369 init_mm_internals(); 1370 1371 do_pre_smp_initcalls(); 1372 lockup_detector_init(); 1373 1374 smp_init(); 1375 sched_init_smp(); 1376 1377 page_alloc_init_late(); 1378 /* Initialize page ext after all struct pages are initialized. */ 1379 page_ext_init(); 1380 1381 do_basic_setup(); 1382 1383 console_on_rootfs(); 1384 1385 /* 1386 * check if there is an early userspace init. If yes, let it do all 1387 * the work 1388 */ 1389 1390 if (!ramdisk_execute_command) 1391 ramdisk_execute_command = "/init"; 1392 1393 if (ksys_access((const char __user *) 1394 ramdisk_execute_command, 0) != 0) { 1395 ramdisk_execute_command = NULL; 1396 prepare_namespace(); 1397 } 1398 1399 /* 1400 * Ok, we have completed the initial bootup, and 1401 * we're essentially up and running. Get rid of the 1402 * initmem segments and start the user-mode stuff.. 1403 * 1404 * rootfs is available now, try loading the public keys 1405 * and default modules 1406 */ 1407 1408 integrity_load_keys(); 1409 } 1410