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