init/main.c

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