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/module.h>
  16 #include <linux/proc_fs.h>
  17 #include <linux/kernel.h>
  18 #include <linux/syscalls.h>
  19 #include <linux/stackprotector.h>
  20 #include <linux/string.h>
  21 #include <linux/ctype.h>
  22 #include <linux/delay.h>
  23 #include <linux/ioport.h>
  24 #include <linux/init.h>
  25 #include <linux/initrd.h>
  26 #include <linux/bootmem.h>
  27 #include <linux/acpi.h>
  28 #include <linux/tty.h>
  29 #include <linux/percpu.h>
  30 #include <linux/kmod.h>
  31 #include <linux/vmalloc.h>
  32 #include <linux/kernel_stat.h>
  33 #include <linux/start_kernel.h>
  34 #include <linux/security.h>
  35 #include <linux/smp.h>
  36 #include <linux/profile.h>
  37 #include <linux/rcupdate.h>
  38 #include <linux/moduleparam.h>
  39 #include <linux/kallsyms.h>
  40 #include <linux/writeback.h>
  41 #include <linux/cpu.h>
  42 #include <linux/cpuset.h>
  43 #include <linux/cgroup.h>
  44 #include <linux/efi.h>
  45 #include <linux/tick.h>
  46 #include <linux/interrupt.h>
  47 #include <linux/taskstats_kern.h>
  48 #include <linux/delayacct.h>
  49 #include <linux/unistd.h>
  50 #include <linux/rmap.h>
  51 #include <linux/mempolicy.h>
  52 #include <linux/key.h>
  53 #include <linux/buffer_head.h>
  54 #include <linux/page_ext.h>
  55 #include <linux/debug_locks.h>
  56 #include <linux/debugobjects.h>
  57 #include <linux/lockdep.h>
  58 #include <linux/kmemleak.h>
  59 #include <linux/pid_namespace.h>
  60 #include <linux/device.h>
  61 #include <linux/kthread.h>
  62 #include <linux/sched.h>
  63 #include <linux/signal.h>
  64 #include <linux/idr.h>
  65 #include <linux/kgdb.h>
  66 #include <linux/ftrace.h>
  67 #include <linux/async.h>
  68 #include <linux/kmemcheck.h>
  69 #include <linux/sfi.h>
  70 #include <linux/shmem_fs.h>
  71 #include <linux/slab.h>
  72 #include <linux/perf_event.h>
  73 #include <linux/file.h>
  74 #include <linux/ptrace.h>
  75 #include <linux/blkdev.h>
  76 #include <linux/elevator.h>
  77 #include <linux/sched_clock.h>
  78 #include <linux/context_tracking.h>
  79 #include <linux/random.h>
  80 #include <linux/list.h>
  81 #include <linux/integrity.h>
  82 #include <linux/proc_ns.h>
  83 #include <linux/io.h>
  84 #include <linux/cache.h>
  85
  86 #include <asm/io.h>
  87 #include <asm/bugs.h>
  88 #include <asm/setup.h>
  89 #include <asm/sections.h>
  90 #include <asm/cacheflush.h>
  91
  92 static int kernel_init(void *);
  93
  94 extern void init_IRQ(void);
  95 extern void fork_init(void);
  96 extern void radix_tree_init(void);
  97
  98 /*
  99  * Debug helper: via this flag we know that we are in 'early bootup code'
 100  * where only the boot processor is running with IRQ disabled.  This means
 101  * two things - IRQ must not be enabled before the flag is cleared and some
 102  * operations which are not allowed with IRQ disabled are allowed while the
 103  * flag is set.
 104  */
 105 bool early_boot_irqs_disabled __read_mostly;
 106
 107 enum system_states system_state __read_mostly;
 108 EXPORT_SYMBOL(system_state);
 109
 110 /*
 111  * Boot command-line arguments
 112  */
 113 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
 114 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
 115
 116 extern void time_init(void);
 117 /* Default late time init is NULL. archs can override this later. */
 118 void (*__initdata late_time_init)(void);
 119
 120 /* Untouched command line saved by arch-specific code. */
 121 char __initdata boot_command_line[COMMAND_LINE_SIZE];
 122 /* Untouched saved command line (eg. for /proc) */
 123 char *saved_command_line;
 124 /* Command line for parameter parsing */
 125 static char *static_command_line;
 126 /* Command line for per-initcall parameter parsing */
 127 static char *initcall_command_line;
 128
 129 static char *execute_command;
 130 static char *ramdisk_execute_command;
 131
 132 /*
 133  * Used to generate warnings if static_key manipulation functions are used
 134  * before jump_label_init is called.
 135  */
 136 bool static_key_initialized __read_mostly;
 137 EXPORT_SYMBOL_GPL(static_key_initialized);
 138
 139 /*
 140  * If set, this is an indication to the drivers that reset the underlying
 141  * device before going ahead with the initialization otherwise driver might
 142  * rely on the BIOS and skip the reset operation.
 143  *
 144  * This is useful if kernel is booting in an unreliable environment.
 145  * For ex. kdump situation where previous kernel has crashed, BIOS has been
 146  * skipped and devices will be in unknown state.
 147  */
 148 unsigned int reset_devices;
 149 EXPORT_SYMBOL(reset_devices);
 150
 151 static int __init set_reset_devices(char *str)
 152 {
 153         reset_devices = 1;
 154         return 1;
 155 }
 156
 157 __setup("reset_devices", set_reset_devices);
 158
 159 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 160 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
 161 static const char *panic_later, *panic_param;
 162
 163 extern const struct obs_kernel_param __setup_start[], __setup_end[];
 164
 165 static bool __init obsolete_checksetup(char *line)
 166 {
 167         const struct obs_kernel_param *p;
 168         bool had_early_param = false;
 169
 170         p = __setup_start;
 171         do {
 172                 int n = strlen(p->str);
 173                 if (parameqn(line, p->str, n)) {
 174                         if (p->early) {
 175                                 /* Already done in parse_early_param?
 176                                  * (Needs exact match on param part).
 177                                  * Keep iterating, as we can have early
 178                                  * params and __setups of same names 8( */
 179                                 if (line[n] == '\0' || line[n] == '=')
 180                                         had_early_param = true;
 181                         } else if (!p->setup_func) {
 182                                 pr_warn("Parameter %s is obsolete, ignored\n",
 183                                         p->str);
 184                                 return true;
 185                         } else if (p->setup_func(line + n))
 186                                 return true;
 187                 }
 188                 p++;
 189         } while (p < __setup_end);
 190
 191         return had_early_param;
 192 }
 193
 194 /*
 195  * This should be approx 2 Bo*oMips to start (note initial shift), and will
 196  * still work even if initially too large, it will just take slightly longer
 197  */
 198 unsigned long loops_per_jiffy = (1<<12);
 199 EXPORT_SYMBOL(loops_per_jiffy);
 200
 201 static int __init debug_kernel(char *str)
 202 {
 203         console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
 204         return 0;
 205 }
 206
 207 static int __init quiet_kernel(char *str)
 208 {
 209         console_loglevel = CONSOLE_LOGLEVEL_QUIET;
 210         return 0;
 211 }
 212
 213 early_param("debug", debug_kernel);
 214 early_param("quiet", quiet_kernel);
 215
 216 static int __init loglevel(char *str)
 217 {
 218         int newlevel;
 219
 220         /*
 221          * Only update loglevel value when a correct setting was passed,
 222          * to prevent blind crashes (when loglevel being set to 0) that
 223          * are quite hard to debug
 224          */
 225         if (get_option(&str, &newlevel)) {
 226                 console_loglevel = newlevel;
 227                 return 0;
 228         }
 229
 230         return -EINVAL;
 231 }
 232
 233 early_param("loglevel", loglevel);
 234
 235 /* Change NUL term back to "=", to make "param" the whole string. */
 236 static int __init repair_env_string(char *param, char *val,
 237                                     const char *unused, void *arg)
 238 {
 239         if (val) {
 240                 /* param=val or param="val"? */
 241                 if (val == param+strlen(param)+1)
 242                         val[-1] = '=';
 243                 else if (val == param+strlen(param)+2) {
 244                         val[-2] = '=';
 245                         memmove(val-1, val, strlen(val)+1);
 246                         val--;
 247                 } else
 248                         BUG();
 249         }
 250         return 0;
 251 }
 252
 253 /* Anything after -- gets handed straight to init. */
 254 static int __init set_init_arg(char *param, char *val,
 255                                const char *unused, void *arg)
 256 {
 257         unsigned int i;
 258
 259         if (panic_later)
 260                 return 0;
 261
 262         repair_env_string(param, val, unused, NULL);
 263
 264         for (i = 0; argv_init[i]; i++) {
 265                 if (i == MAX_INIT_ARGS) {
 266                         panic_later = "init";
 267                         panic_param = param;
 268                         return 0;
 269                 }
 270         }
 271         argv_init[i] = param;
 272         return 0;
 273 }
 274
 275 /*
 276  * Unknown boot options get handed to init, unless they look like
 277  * unused parameters (modprobe will find them in /proc/cmdline).
 278  */
 279 static int __init unknown_bootoption(char *param, char *val,
 280                                      const char *unused, void *arg)
 281 {
 282         repair_env_string(param, val, unused, NULL);
 283
 284         /* Handle obsolete-style parameters */
 285         if (obsolete_checksetup(param))
 286                 return 0;
 287
 288         /* Unused module parameter. */
 289         if (strchr(param, '.') && (!val || strchr(param, '.') < val))
 290                 return 0;
 291
 292         if (panic_later)
 293                 return 0;
 294
 295         if (val) {
 296                 /* Environment option */
 297                 unsigned int i;
 298                 for (i = 0; envp_init[i]; i++) {
 299                         if (i == MAX_INIT_ENVS) {
 300                                 panic_later = "env";
 301                                 panic_param = param;
 302                         }
 303                         if (!strncmp(param, envp_init[i], val - param))
 304                                 break;
 305                 }
 306                 envp_init[i] = param;
 307         } else {
 308                 /* Command line option */
 309                 unsigned int i;
 310                 for (i = 0; argv_init[i]; i++) {
 311                         if (i == MAX_INIT_ARGS) {
 312                                 panic_later = "init";
 313                                 panic_param = param;
 314                         }
 315                 }
 316                 argv_init[i] = param;
 317         }
 318         return 0;
 319 }
 320
 321 static int __init init_setup(char *str)
 322 {
 323         unsigned int i;
 324
 325         execute_command = str;
 326         /*
 327          * In case LILO is going to boot us with default command line,
 328          * it prepends "auto" before the whole cmdline which makes
 329          * the shell think it should execute a script with such name.
 330          * So we ignore all arguments entered _before_ init=... [MJ]
 331          */
 332         for (i = 1; i < MAX_INIT_ARGS; i++)
 333                 argv_init[i] = NULL;
 334         return 1;
 335 }
 336 __setup("init=", init_setup);
 337
 338 static int __init rdinit_setup(char *str)
 339 {
 340         unsigned int i;
 341
 342         ramdisk_execute_command = str;
 343         /* See "auto" comment in init_setup */
 344         for (i = 1; i < MAX_INIT_ARGS; i++)
 345                 argv_init[i] = NULL;
 346         return 1;
 347 }
 348 __setup("rdinit=", rdinit_setup);
 349
 350 #ifndef CONFIG_SMP
 351 static const unsigned int setup_max_cpus = NR_CPUS;
 352 static inline void setup_nr_cpu_ids(void) { }
 353 static inline void smp_prepare_cpus(unsigned int maxcpus) { }
 354 #endif
 355
 356 /*
 357  * We need to store the untouched command line for future reference.
 358  * We also need to store the touched command line since the parameter
 359  * parsing is performed in place, and we should allow a component to
 360  * store reference of name/value for future reference.
 361  */
 362 static void __init setup_command_line(char *command_line)
 363 {
 364         saved_command_line =
 365                 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
 366         initcall_command_line =
 367                 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
 368         static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0);
 369         strcpy(saved_command_line, boot_command_line);
 370         strcpy(static_command_line, command_line);
 371 }
 372
 373 /*
 374  * We need to finalize in a non-__init function or else race conditions
 375  * between the root thread and the init thread may cause start_kernel to
 376  * be reaped by free_initmem before the root thread has proceeded to
 377  * cpu_idle.
 378  *
 379  * gcc-3.4 accidentally inlines this function, so use noinline.
 380  */
 381
 382 static __initdata DECLARE_COMPLETION(kthreadd_done);
 383
 384 static noinline void __ref rest_init(void)
 385 {
 386         int pid;
 387
 388         rcu_scheduler_starting();
 389         /*
 390          * We need to spawn init first so that it obtains pid 1, however
 391          * the init task will end up wanting to create kthreads, which, if
 392          * we schedule it before we create kthreadd, will OOPS.
 393          */
 394         kernel_thread(kernel_init, NULL, CLONE_FS);
 395         numa_default_policy();
 396         pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
 397         rcu_read_lock();
 398         kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
 399         rcu_read_unlock();
 400         complete(&kthreadd_done);
 401
 402         /*
 403          * The boot idle thread must execute schedule()
 404          * at least once to get things moving:
 405          */
 406         init_idle_bootup_task(current);
 407         schedule_preempt_disabled();
 408         /* Call into cpu_idle with preempt disabled */
 409         cpu_startup_entry(CPUHP_ONLINE);
 410 }
 411
 412 /* Check for early params. */
 413 static int __init do_early_param(char *param, char *val,
 414                                  const char *unused, void *arg)
 415 {
 416         const struct obs_kernel_param *p;
 417
 418         for (p = __setup_start; p < __setup_end; p++) {
 419                 if ((p->early && parameq(param, p->str)) ||
 420                     (strcmp(param, "console") == 0 &&
 421                      strcmp(p->str, "earlycon") == 0)
 422                 ) {
 423                         if (p->setup_func(val) != 0)
 424                                 pr_warn("Malformed early option '%s'\n", param);
 425                 }
 426         }
 427         /* We accept everything at this stage. */
 428         return 0;
 429 }
 430
 431 void __init parse_early_options(char *cmdline)
 432 {
 433         parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
 434                    do_early_param);
 435 }
 436
 437 /* Arch code calls this early on, or if not, just before other parsing. */
 438 void __init parse_early_param(void)
 439 {
 440         static int done __initdata;
 441         static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
 442
 443         if (done)
 444                 return;
 445
 446         /* All fall through to do_early_param. */
 447         strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 448         parse_early_options(tmp_cmdline);
 449         done = 1;
 450 }
 451
 452 void __init __weak arch_post_acpi_subsys_init(void) { }
 453
 454 void __init __weak smp_setup_processor_id(void)
 455 {
 456 }
 457
 458 # if THREAD_SIZE >= PAGE_SIZE
 459 void __init __weak thread_stack_cache_init(void)
 460 {
 461 }
 462 #endif
 463
 464 /*
 465  * Set up kernel memory allocators
 466  */
 467 static void __init mm_init(void)
 468 {
 469         /*
 470          * page_ext requires contiguous pages,
 471          * bigger than MAX_ORDER unless SPARSEMEM.
 472          */
 473         page_ext_init_flatmem();
 474         mem_init();
 475         kmem_cache_init();
 476         percpu_init_late();
 477         pgtable_init();
 478         vmalloc_init();
 479         ioremap_huge_init();
 480 }
 481
 482 asmlinkage __visible void __init start_kernel(void)
 483 {
 484         char *command_line;
 485         char *after_dashes;
 486
 487         set_task_stack_end_magic(&init_task);
 488         smp_setup_processor_id();
 489         debug_objects_early_init();
 490
 491         /*
 492          * Set up the the initial canary ASAP:
 493          */
 494         boot_init_stack_canary();
 495
 496         cgroup_init_early();
 497
 498         local_irq_disable();
 499         early_boot_irqs_disabled = true;
 500
 501 /*
 502  * Interrupts are still disabled. Do necessary setups, then
 503  * enable them
 504  */
 505         boot_cpu_init();
 506         page_address_init();
 507         pr_notice("%s", linux_banner);
 508         setup_arch(&command_line);
 509         mm_init_cpumask(&init_mm);
 510         setup_command_line(command_line);
 511         setup_nr_cpu_ids();
 512         setup_per_cpu_areas();
 513         boot_cpu_state_init();
 514         smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
 515
 516         build_all_zonelists(NULL, NULL);
 517         page_alloc_init();
 518
 519         pr_notice("Kernel command line: %s\n", boot_command_line);
 520         parse_early_param();
 521         after_dashes = parse_args("Booting kernel",
 522                                   static_command_line, __start___param,
 523                                   __stop___param - __start___param,
 524                                   -1, -1, NULL, &unknown_bootoption);
 525         if (!IS_ERR_OR_NULL(after_dashes))
 526                 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
 527                            NULL, set_init_arg);
 528
 529         jump_label_init();
 530
 531         /*
 532          * These use large bootmem allocations and must precede
 533          * kmem_cache_init()
 534          */
 535         setup_log_buf(0);
 536         pidhash_init();
 537         vfs_caches_init_early();
 538         sort_main_extable();
 539         trap_init();
 540         mm_init();
 541
 542         /*
 543          * Set up the scheduler prior starting any interrupts (such as the
 544          * timer interrupt). Full topology setup happens at smp_init()
 545          * time - but meanwhile we still have a functioning scheduler.
 546          */
 547         sched_init();
 548         /*
 549          * Disable preemption - early bootup scheduling is extremely
 550          * fragile until we cpu_idle() for the first time.
 551          */
 552         preempt_disable();
 553         if (WARN(!irqs_disabled(),
 554                  "Interrupts were enabled *very* early, fixing it\n"))
 555                 local_irq_disable();
 556         idr_init_cache();
 557
 558         /*
 559          * Allow workqueue creation and work item queueing/cancelling
 560          * early.  Work item execution depends on kthreads and starts after
 561          * workqueue_init().
 562          */
 563         workqueue_init_early();
 564
 565         rcu_init();
 566
 567         /* trace_printk() and trace points may be used after this */
 568         trace_init();
 569
 570         context_tracking_init();
 571         radix_tree_init();
 572         /* init some links before init_ISA_irqs() */
 573         early_irq_init();
 574         init_IRQ();
 575         tick_init();
 576         rcu_init_nohz();
 577         init_timers();
 578         hrtimers_init();
 579         softirq_init();
 580         timekeeping_init();
 581         time_init();
 582         sched_clock_postinit();
 583         printk_nmi_init();
 584         perf_event_init();
 585         profile_init();
 586         call_function_init();
 587         WARN(!irqs_disabled(), "Interrupts were enabled early\n");
 588         early_boot_irqs_disabled = false;
 589         local_irq_enable();
 590
 591         kmem_cache_init_late();
 592
 593         /*
 594          * HACK ALERT! This is early. We're enabling the console before
 595          * we've done PCI setups etc, and console_init() must be aware of
 596          * this. But we do want output early, in case something goes wrong.
 597          */
 598         console_init();
 599         if (panic_later)
 600                 panic("Too many boot %s vars at `%s'", panic_later,
 601                       panic_param);
 602
 603         lockdep_info();
 604
 605         /*
 606          * Need to run this when irqs are enabled, because it wants
 607          * to self-test [hard/soft]-irqs on/off lock inversion bugs
 608          * too:
 609          */
 610         locking_selftest();
 611
 612 #ifdef CONFIG_BLK_DEV_INITRD
 613         if (initrd_start && !initrd_below_start_ok &&
 614             page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
 615                 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
 616                     page_to_pfn(virt_to_page((void *)initrd_start)),
 617                     min_low_pfn);
 618                 initrd_start = 0;
 619         }
 620 #endif
 621         page_ext_init();
 622         debug_objects_mem_init();
 623         kmemleak_init();
 624         setup_per_cpu_pageset();
 625         numa_policy_init();
 626         if (late_time_init)
 627                 late_time_init();
 628         sched_clock_init();
 629         calibrate_delay();
 630         pidmap_init();
 631         anon_vma_init();
 632         acpi_early_init();
 633 #ifdef CONFIG_X86
 634         if (efi_enabled(EFI_RUNTIME_SERVICES))
 635                 efi_enter_virtual_mode();
 636 #endif
 637 #ifdef CONFIG_X86_ESPFIX64
 638         /* Should be run before the first non-init thread is created */
 639         init_espfix_bsp();
 640 #endif
 641         thread_stack_cache_init();
 642         cred_init();
 643         fork_init();
 644         proc_caches_init();
 645         buffer_init();
 646         key_init();
 647         security_init();
 648         dbg_late_init();
 649         vfs_caches_init();
 650         pagecache_init();
 651         signals_init();
 652         proc_root_init();
 653         nsfs_init();
 654         cpuset_init();
 655         cgroup_init();
 656         taskstats_init_early();
 657         delayacct_init();
 658
 659         check_bugs();
 660
 661         acpi_subsystem_init();
 662         arch_post_acpi_subsys_init();
 663         sfi_init_late();
 664
 665         if (efi_enabled(EFI_RUNTIME_SERVICES)) {
 666                 efi_late_init();
 667                 efi_free_boot_services();
 668         }
 669
 670         ftrace_init();
 671
 672         /* Do the rest non-__init'ed, we're now alive */
 673         rest_init();
 674 }
 675
 676 /* Call all constructor functions linked into the kernel. */
 677 static void __init do_ctors(void)
 678 {
 679 #ifdef CONFIG_CONSTRUCTORS
 680         ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
 681
 682         for (; fn < (ctor_fn_t *) __ctors_end; fn++)
 683                 (*fn)();
 684 #endif
 685 }
 686
 687 bool initcall_debug;
 688 core_param(initcall_debug, initcall_debug, bool, 0644);
 689
 690 #ifdef CONFIG_KALLSYMS
 691 struct blacklist_entry {
 692         struct list_head next;
 693         char *buf;
 694 };
 695
 696 static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
 697
 698 static int __init initcall_blacklist(char *str)
 699 {
 700         char *str_entry;
 701         struct blacklist_entry *entry;
 702
 703         /* str argument is a comma-separated list of functions */
 704         do {
 705                 str_entry = strsep(&str, ",");
 706                 if (str_entry) {
 707                         pr_debug("blacklisting initcall %s\n", str_entry);
 708                         entry = alloc_bootmem(sizeof(*entry));
 709                         entry->buf = alloc_bootmem(strlen(str_entry) + 1);
 710                         strcpy(entry->buf, str_entry);
 711                         list_add(&entry->next, &blacklisted_initcalls);
 712                 }
 713         } while (str_entry);
 714
 715         return 0;
 716 }
 717
 718 static bool __init_or_module initcall_blacklisted(initcall_t fn)
 719 {
 720         struct blacklist_entry *entry;
 721         char fn_name[KSYM_SYMBOL_LEN];
 722         unsigned long addr;
 723
 724         if (list_empty(&blacklisted_initcalls))
 725                 return false;
 726
 727         addr = (unsigned long) dereference_function_descriptor(fn);
 728         sprint_symbol_no_offset(fn_name, addr);
 729
 730         /*
 731          * fn will be "function_name [module_name]" where [module_name] is not
 732          * displayed for built-in init functions.  Strip off the [module_name].
 733          */
 734         strreplace(fn_name, ' ', '\0');
 735
 736         list_for_each_entry(entry, &blacklisted_initcalls, next) {
 737                 if (!strcmp(fn_name, entry->buf)) {
 738                         pr_debug("initcall %s blacklisted\n", fn_name);
 739                         return true;
 740                 }
 741         }
 742
 743         return false;
 744 }
 745 #else
 746 static int __init initcall_blacklist(char *str)
 747 {
 748         pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
 749         return 0;
 750 }
 751
 752 static bool __init_or_module initcall_blacklisted(initcall_t fn)
 753 {
 754         return false;
 755 }
 756 #endif
 757 __setup("initcall_blacklist=", initcall_blacklist);
 758
 759 static int __init_or_module do_one_initcall_debug(initcall_t fn)
 760 {
 761         ktime_t calltime, delta, rettime;
 762         unsigned long long duration;
 763         int ret;
 764
 765         printk(KERN_DEBUG "calling  %pF @ %i\n", fn, task_pid_nr(current));
 766         calltime = ktime_get();
 767         ret = fn();
 768         rettime = ktime_get();
 769         delta = ktime_sub(rettime, calltime);
 770         duration = (unsigned long long) ktime_to_ns(delta) >> 10;
 771         printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n",
 772                  fn, ret, duration);
 773
 774         return ret;
 775 }
 776
 777 int __init_or_module do_one_initcall(initcall_t fn)
 778 {
 779         int count = preempt_count();
 780         int ret;
 781         char msgbuf[64];
 782
 783         if (initcall_blacklisted(fn))
 784                 return -EPERM;
 785
 786         if (initcall_debug)
 787                 ret = do_one_initcall_debug(fn);
 788         else
 789                 ret = fn();
 790
 791         msgbuf[0] = 0;
 792
 793         if (preempt_count() != count) {
 794                 sprintf(msgbuf, "preemption imbalance ");
 795                 preempt_count_set(count);
 796         }
 797         if (irqs_disabled()) {
 798                 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
 799                 local_irq_enable();
 800         }
 801         WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
 802
 803         add_latent_entropy();
 804         return ret;
 805 }
 806
 807
 808 extern initcall_t __initcall_start[];
 809 extern initcall_t __initcall0_start[];
 810 extern initcall_t __initcall1_start[];
 811 extern initcall_t __initcall2_start[];
 812 extern initcall_t __initcall3_start[];
 813 extern initcall_t __initcall4_start[];
 814 extern initcall_t __initcall5_start[];
 815 extern initcall_t __initcall6_start[];
 816 extern initcall_t __initcall7_start[];
 817 extern initcall_t __initcall_end[];
 818
 819 static initcall_t *initcall_levels[] __initdata = {
 820         __initcall0_start,
 821         __initcall1_start,
 822         __initcall2_start,
 823         __initcall3_start,
 824         __initcall4_start,
 825         __initcall5_start,
 826         __initcall6_start,
 827         __initcall7_start,
 828         __initcall_end,
 829 };
 830
 831 /* Keep these in sync with initcalls in include/linux/init.h */
 832 static char *initcall_level_names[] __initdata = {
 833         "early",
 834         "core",
 835         "postcore",
 836         "arch",
 837         "subsys",
 838         "fs",
 839         "device",
 840         "late",
 841 };
 842
 843 static void __init do_initcall_level(int level)
 844 {
 845         initcall_t *fn;
 846
 847         strcpy(initcall_command_line, saved_command_line);
 848         parse_args(initcall_level_names[level],
 849                    initcall_command_line, __start___param,
 850                    __stop___param - __start___param,
 851                    level, level,
 852                    NULL, &repair_env_string);
 853
 854         for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
 855                 do_one_initcall(*fn);
 856 }
 857
 858 static void __init do_initcalls(void)
 859 {
 860         int level;
 861
 862         for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
 863                 do_initcall_level(level);
 864 }
 865
 866 /*
 867  * Ok, the machine is now initialized. None of the devices
 868  * have been touched yet, but the CPU subsystem is up and
 869  * running, and memory and process management works.
 870  *
 871  * Now we can finally start doing some real work..
 872  */
 873 static void __init do_basic_setup(void)
 874 {
 875         cpuset_init_smp();
 876         shmem_init();
 877         driver_init();
 878         init_irq_proc();
 879         do_ctors();
 880         usermodehelper_enable();
 881         do_initcalls();
 882         random_int_secret_init();
 883 }
 884
 885 static void __init do_pre_smp_initcalls(void)
 886 {
 887         initcall_t *fn;
 888
 889         for (fn = __initcall_start; fn < __initcall0_start; fn++)
 890                 do_one_initcall(*fn);
 891 }
 892
 893 /*
 894  * This function requests modules which should be loaded by default and is
 895  * called twice right after initrd is mounted and right before init is
 896  * exec'd.  If such modules are on either initrd or rootfs, they will be
 897  * loaded before control is passed to userland.
 898  */
 899 void __init load_default_modules(void)
 900 {
 901         load_default_elevator_module();
 902 }
 903
 904 static int run_init_process(const char *init_filename)
 905 {
 906         argv_init[0] = init_filename;
 907         return do_execve(getname_kernel(init_filename),
 908                 (const char __user *const __user *)argv_init,
 909                 (const char __user *const __user *)envp_init);
 910 }
 911
 912 static int try_to_run_init_process(const char *init_filename)
 913 {
 914         int ret;
 915
 916         ret = run_init_process(init_filename);
 917
 918         if (ret && ret != -ENOENT) {
 919                 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
 920                        init_filename, ret);
 921         }
 922
 923         return ret;
 924 }
 925
 926 static noinline void __init kernel_init_freeable(void);
 927
 928 #if defined(CONFIG_DEBUG_RODATA) || defined(CONFIG_DEBUG_SET_MODULE_RONX)
 929 bool rodata_enabled __ro_after_init = true;
 930 static int __init set_debug_rodata(char *str)
 931 {
 932         return strtobool(str, &rodata_enabled);
 933 }
 934 __setup("rodata=", set_debug_rodata);
 935 #endif
 936
 937 #ifdef CONFIG_DEBUG_RODATA
 938 static void mark_readonly(void)
 939 {
 940         if (rodata_enabled)
 941                 mark_rodata_ro();
 942         else
 943                 pr_info("Kernel memory protection disabled.\n");
 944 }
 945 #else
 946 static inline void mark_readonly(void)
 947 {
 948         pr_warn("This architecture does not have kernel memory protection.\n");
 949 }
 950 #endif
 951
 952 static int __ref kernel_init(void *unused)
 953 {
 954         int ret;
 955
 956         kernel_init_freeable();
 957         /* need to finish all async __init code before freeing the memory */
 958         async_synchronize_full();
 959         free_initmem();
 960         mark_readonly();
 961         system_state = SYSTEM_RUNNING;
 962         numa_default_policy();
 963
 964         flush_delayed_fput();
 965
 966         rcu_end_inkernel_boot();
 967
 968         if (ramdisk_execute_command) {
 969                 ret = run_init_process(ramdisk_execute_command);
 970                 if (!ret)
 971                         return 0;
 972                 pr_err("Failed to execute %s (error %d)\n",
 973                        ramdisk_execute_command, ret);
 974         }
 975
 976         /*
 977          * We try each of these until one succeeds.
 978          *
 979          * The Bourne shell can be used instead of init if we are
 980          * trying to recover a really broken machine.
 981          */
 982         if (execute_command) {
 983                 ret = run_init_process(execute_command);
 984                 if (!ret)
 985                         return 0;
 986                 panic("Requested init %s failed (error %d).",
 987                       execute_command, ret);
 988         }
 989         if (!try_to_run_init_process("/sbin/init") ||
 990             !try_to_run_init_process("/etc/init") ||
 991             !try_to_run_init_process("/bin/init") ||
 992             !try_to_run_init_process("/bin/sh"))
 993                 return 0;
 994
 995         panic("No working init found.  Try passing init= option to kernel. "
 996               "See Linux Documentation/admin-guide/init.rst for guidance.");
 997 }
 998
 999 static noinline void __init kernel_init_freeable(void)
1000 {
1001         /*
1002          * Wait until kthreadd is all set-up.
1003          */
1004         wait_for_completion(&kthreadd_done);
1005
1006         /* Now the scheduler is fully set up and can do blocking allocations */
1007         gfp_allowed_mask = __GFP_BITS_MASK;
1008
1009         /*
1010          * init can allocate pages on any node
1011          */
1012         set_mems_allowed(node_states[N_MEMORY]);
1013         /*
1014          * init can run on any cpu.
1015          */
1016         set_cpus_allowed_ptr(current, cpu_all_mask);
1017
1018         cad_pid = task_pid(current);
1019
1020         smp_prepare_cpus(setup_max_cpus);
1021
1022         workqueue_init();
1023
1024         do_pre_smp_initcalls();
1025         lockup_detector_init();
1026
1027         smp_init();
1028         sched_init_smp();
1029
1030         page_alloc_init_late();
1031
1032         do_basic_setup();
1033
1034         /* Open the /dev/console on the rootfs, this should never fail */
1035         if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
1036                 pr_err("Warning: unable to open an initial console.\n");
1037
1038         (void) sys_dup(0);
1039         (void) sys_dup(0);
1040         /*
1041          * check if there is an early userspace init.  If yes, let it do all
1042          * the work
1043          */
1044
1045         if (!ramdisk_execute_command)
1046                 ramdisk_execute_command = "/init";
1047
1048         if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
1049                 ramdisk_execute_command = NULL;
1050                 prepare_namespace();
1051         }
1052
1053         /*
1054          * Ok, we have completed the initial bootup, and
1055          * we're essentially up and running. Get rid of the
1056          * initmem segments and start the user-mode stuff..
1057          *
1058          * rootfs is available now, try loading the public keys
1059          * and default modules
1060          */
1061
1062         integrity_load_keys();
1063         load_default_modules();
1064 }