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
  85 #include <asm/io.h>
  86 #include <asm/bugs.h>
  87 #include <asm/setup.h>
  88 #include <asm/sections.h>
  89 #include <asm/cacheflush.h>
  90
  91 static int kernel_init(void *);
  92
  93 extern void init_IRQ(void);
  94 extern void fork_init(unsigned long);
  95 extern void radix_tree_init(void);
  96 #ifndef CONFIG_DEBUG_RODATA
  97 static inline void mark_rodata_ro(void) { }
  98 #endif
  99
 100 /*
 101  * Debug helper: via this flag we know that we are in 'early bootup code'
 102  * where only the boot processor is running with IRQ disabled.  This means
 103  * two things - IRQ must not be enabled before the flag is cleared and some
 104  * operations which are not allowed with IRQ disabled are allowed while the
 105  * flag is set.
 106  */
 107 bool early_boot_irqs_disabled __read_mostly;
 108
 109 enum system_states system_state __read_mostly;
 110 EXPORT_SYMBOL(system_state);
 111
 112 /*
 113  * Boot command-line arguments
 114  */
 115 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
 116 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
 117
 118 extern void time_init(void);
 119 /* Default late time init is NULL. archs can override this later. */
 120 void (*__initdata late_time_init)(void);
 121
 122 /* Untouched command line saved by arch-specific code. */
 123 char __initdata boot_command_line[COMMAND_LINE_SIZE];
 124 /* Untouched saved command line (eg. for /proc) */
 125 char *saved_command_line;
 126 /* Command line for parameter parsing */
 127 static char *static_command_line;
 128 /* Command line for per-initcall parameter parsing */
 129 static char *initcall_command_line;
 130
 131 static char *execute_command;
 132 static char *ramdisk_execute_command;
 133
 134 /*
 135  * Used to generate warnings if static_key manipulation functions are used
 136  * before jump_label_init is called.
 137  */
 138 bool static_key_initialized __read_mostly;
 139 EXPORT_SYMBOL_GPL(static_key_initialized);
 140
 141 /*
 142  * If set, this is an indication to the drivers that reset the underlying
 143  * device before going ahead with the initialization otherwise driver might
 144  * rely on the BIOS and skip the reset operation.
 145  *
 146  * This is useful if kernel is booting in an unreliable environment.
 147  * For ex. kdump situation where previous kernel has crashed, BIOS has been
 148  * skipped and devices will be in unknown state.
 149  */
 150 unsigned int reset_devices;
 151 EXPORT_SYMBOL(reset_devices);
 152
 153 static int __init set_reset_devices(char *str)
 154 {
 155         reset_devices = 1;
 156         return 1;
 157 }
 158
 159 __setup("reset_devices", set_reset_devices);
 160
 161 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 162 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
 163 static const char *panic_later, *panic_param;
 164
 165 extern const struct obs_kernel_param __setup_start[], __setup_end[];
 166
 167 static int __init obsolete_checksetup(char *line)
 168 {
 169         const struct obs_kernel_param *p;
 170         int had_early_param = 0;
 171
 172         p = __setup_start;
 173         do {
 174                 int n = strlen(p->str);
 175                 if (parameqn(line, p->str, n)) {
 176                         if (p->early) {
 177                                 /* Already done in parse_early_param?
 178                                  * (Needs exact match on param part).
 179                                  * Keep iterating, as we can have early
 180                                  * params and __setups of same names 8( */
 181                                 if (line[n] == '\0' || line[n] == '=')
 182                                         had_early_param = 1;
 183                         } else if (!p->setup_func) {
 184                                 pr_warn("Parameter %s is obsolete, ignored\n",
 185                                         p->str);
 186                                 return 1;
 187                         } else if (p->setup_func(line + n))
 188                                 return 1;
 189                 }
 190                 p++;
 191         } while (p < __setup_end);
 192
 193         return had_early_param;
 194 }
 195
 196 /*
 197  * This should be approx 2 Bo*oMips to start (note initial shift), and will
 198  * still work even if initially too large, it will just take slightly longer
 199  */
 200 unsigned long loops_per_jiffy = (1<<12);
 201 EXPORT_SYMBOL(loops_per_jiffy);
 202
 203 static int __init debug_kernel(char *str)
 204 {
 205         console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
 206         return 0;
 207 }
 208
 209 static int __init quiet_kernel(char *str)
 210 {
 211         console_loglevel = CONSOLE_LOGLEVEL_QUIET;
 212         return 0;
 213 }
 214
 215 early_param("debug", debug_kernel);
 216 early_param("quiet", quiet_kernel);
 217
 218 static int __init loglevel(char *str)
 219 {
 220         int newlevel;
 221
 222         /*
 223          * Only update loglevel value when a correct setting was passed,
 224          * to prevent blind crashes (when loglevel being set to 0) that
 225          * are quite hard to debug
 226          */
 227         if (get_option(&str, &newlevel)) {
 228                 console_loglevel = newlevel;
 229                 return 0;
 230         }
 231
 232         return -EINVAL;
 233 }
 234
 235 early_param("loglevel", loglevel);
 236
 237 /* Change NUL term back to "=", to make "param" the whole string. */
 238 static int __init repair_env_string(char *param, char *val, const char *unused)
 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, const char *unused)
 256 {
 257         unsigned int i;
 258
 259         if (panic_later)
 260                 return 0;
 261
 262         repair_env_string(param, val, unused);
 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, const char *unused)
 280 {
 281         repair_env_string(param, val, unused);
 282
 283         /* Handle obsolete-style parameters */
 284         if (obsolete_checksetup(param))
 285                 return 0;
 286
 287         /* Unused module parameter. */
 288         if (strchr(param, '.') && (!val || strchr(param, '.') < val))
 289                 return 0;
 290
 291         if (panic_later)
 292                 return 0;
 293
 294         if (val) {
 295                 /* Environment option */
 296                 unsigned int i;
 297                 for (i = 0; envp_init[i]; i++) {
 298                         if (i == MAX_INIT_ENVS) {
 299                                 panic_later = "env";
 300                                 panic_param = param;
 301                         }
 302                         if (!strncmp(param, envp_init[i], val - param))
 303                                 break;
 304                 }
 305                 envp_init[i] = param;
 306         } else {
 307                 /* Command line option */
 308                 unsigned int i;
 309                 for (i = 0; argv_init[i]; i++) {
 310                         if (i == MAX_INIT_ARGS) {
 311                                 panic_later = "init";
 312                                 panic_param = param;
 313                         }
 314                 }
 315                 argv_init[i] = param;
 316         }
 317         return 0;
 318 }
 319
 320 static int __init init_setup(char *str)
 321 {
 322         unsigned int i;
 323
 324         execute_command = str;
 325         /*
 326          * In case LILO is going to boot us with default command line,
 327          * it prepends "auto" before the whole cmdline which makes
 328          * the shell think it should execute a script with such name.
 329          * So we ignore all arguments entered _before_ init=... [MJ]
 330          */
 331         for (i = 1; i < MAX_INIT_ARGS; i++)
 332                 argv_init[i] = NULL;
 333         return 1;
 334 }
 335 __setup("init=", init_setup);
 336
 337 static int __init rdinit_setup(char *str)
 338 {
 339         unsigned int i;
 340
 341         ramdisk_execute_command = str;
 342         /* See "auto" comment in init_setup */
 343         for (i = 1; i < MAX_INIT_ARGS; i++)
 344                 argv_init[i] = NULL;
 345         return 1;
 346 }
 347 __setup("rdinit=", rdinit_setup);
 348
 349 #ifndef CONFIG_SMP
 350 static const unsigned int setup_max_cpus = NR_CPUS;
 351 static inline void setup_nr_cpu_ids(void) { }
 352 static inline void smp_prepare_cpus(unsigned int maxcpus) { }
 353 #endif
 354
 355 /*
 356  * We need to store the untouched command line for future reference.
 357  * We also need to store the touched command line since the parameter
 358  * parsing is performed in place, and we should allow a component to
 359  * store reference of name/value for future reference.
 360  */
 361 static void __init setup_command_line(char *command_line)
 362 {
 363         saved_command_line =
 364                 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
 365         initcall_command_line =
 366                 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
 367         static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0);
 368         strcpy(saved_command_line, boot_command_line);
 369         strcpy(static_command_line, command_line);
 370 }
 371
 372 /*
 373  * We need to finalize in a non-__init function or else race conditions
 374  * between the root thread and the init thread may cause start_kernel to
 375  * be reaped by free_initmem before the root thread has proceeded to
 376  * cpu_idle.
 377  *
 378  * gcc-3.4 accidentally inlines this function, so use noinline.
 379  */
 380
 381 static __initdata DECLARE_COMPLETION(kthreadd_done);
 382
 383 static noinline void __init_refok rest_init(void)
 384 {
 385         int pid;
 386
 387         rcu_scheduler_starting();
 388         smpboot_thread_init();
 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, const char *unused)
 414 {
 415         const struct obs_kernel_param *p;
 416
 417         for (p = __setup_start; p < __setup_end; p++) {
 418                 if ((p->early && parameq(param, p->str)) ||
 419                     (strcmp(param, "console") == 0 &&
 420                      strcmp(p->str, "earlycon") == 0)
 421                 ) {
 422                         if (p->setup_func(val) != 0)
 423                                 pr_warn("Malformed early option '%s'\n", param);
 424                 }
 425         }
 426         /* We accept everything at this stage. */
 427         return 0;
 428 }
 429
 430 void __init parse_early_options(char *cmdline)
 431 {
 432         parse_args("early options", cmdline, NULL, 0, 0, 0, do_early_param);
 433 }
 434
 435 /* Arch code calls this early on, or if not, just before other parsing. */
 436 void __init parse_early_param(void)
 437 {
 438         static int done __initdata;
 439         static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
 440
 441         if (done)
 442                 return;
 443
 444         /* All fall through to do_early_param. */
 445         strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 446         parse_early_options(tmp_cmdline);
 447         done = 1;
 448 }
 449
 450 /*
 451  *      Activate the first processor.
 452  */
 453
 454 static void __init boot_cpu_init(void)
 455 {
 456         int cpu = smp_processor_id();
 457         /* Mark the boot cpu "present", "online" etc for SMP and UP case */
 458         set_cpu_online(cpu, true);
 459         set_cpu_active(cpu, true);
 460         set_cpu_present(cpu, true);
 461         set_cpu_possible(cpu, true);
 462 }
 463
 464 void __init __weak smp_setup_processor_id(void)
 465 {
 466 }
 467
 468 # if THREAD_SIZE >= PAGE_SIZE
 469 void __init __weak thread_info_cache_init(void)
 470 {
 471 }
 472 #endif
 473
 474 /*
 475  * Set up kernel memory allocators
 476  */
 477 static void __init mm_init(void)
 478 {
 479         /*
 480          * page_ext requires contiguous pages,
 481          * bigger than MAX_ORDER unless SPARSEMEM.
 482          */
 483         page_ext_init_flatmem();
 484         mem_init();
 485         kmem_cache_init();
 486         percpu_init_late();
 487         pgtable_init();
 488         vmalloc_init();
 489         ioremap_huge_init();
 490 }
 491
 492 asmlinkage __visible void __init start_kernel(void)
 493 {
 494         char *command_line;
 495         char *after_dashes;
 496
 497         /*
 498          * Need to run as early as possible, to initialize the
 499          * lockdep hash:
 500          */
 501         lockdep_init();
 502         set_task_stack_end_magic(&init_task);
 503         smp_setup_processor_id();
 504         debug_objects_early_init();
 505
 506         /*
 507          * Set up the the initial canary ASAP:
 508          */
 509         boot_init_stack_canary();
 510
 511         cgroup_init_early();
 512
 513         local_irq_disable();
 514         early_boot_irqs_disabled = true;
 515
 516 /*
 517  * Interrupts are still disabled. Do necessary setups, then
 518  * enable them
 519  */
 520         boot_cpu_init();
 521         page_address_init();
 522         pr_notice("%s", linux_banner);
 523         setup_arch(&command_line);
 524         mm_init_cpumask(&init_mm);
 525         setup_command_line(command_line);
 526         setup_nr_cpu_ids();
 527         setup_per_cpu_areas();
 528         smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
 529
 530         build_all_zonelists(NULL, NULL);
 531         page_alloc_init();
 532
 533         pr_notice("Kernel command line: %s\n", boot_command_line);
 534         parse_early_param();
 535         after_dashes = parse_args("Booting kernel",
 536                                   static_command_line, __start___param,
 537                                   __stop___param - __start___param,
 538                                   -1, -1, &unknown_bootoption);
 539         if (!IS_ERR_OR_NULL(after_dashes))
 540                 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
 541                            set_init_arg);
 542
 543         jump_label_init();
 544
 545         /*
 546          * These use large bootmem allocations and must precede
 547          * kmem_cache_init()
 548          */
 549         setup_log_buf(0);
 550         pidhash_init();
 551         vfs_caches_init_early();
 552         sort_main_extable();
 553         trap_init();
 554         mm_init();
 555
 556         /*
 557          * Set up the scheduler prior starting any interrupts (such as the
 558          * timer interrupt). Full topology setup happens at smp_init()
 559          * time - but meanwhile we still have a functioning scheduler.
 560          */
 561         sched_init();
 562         /*
 563          * Disable preemption - early bootup scheduling is extremely
 564          * fragile until we cpu_idle() for the first time.
 565          */
 566         preempt_disable();
 567         if (WARN(!irqs_disabled(),
 568                  "Interrupts were enabled *very* early, fixing it\n"))
 569                 local_irq_disable();
 570         idr_init_cache();
 571         rcu_init();
 572
 573         /* trace_printk() and trace points may be used after this */
 574         trace_init();
 575
 576         context_tracking_init();
 577         radix_tree_init();
 578         /* init some links before init_ISA_irqs() */
 579         early_irq_init();
 580         init_IRQ();
 581         tick_init();
 582         rcu_init_nohz();
 583         init_timers();
 584         hrtimers_init();
 585         softirq_init();
 586         timekeeping_init();
 587         time_init();
 588         sched_clock_postinit();
 589         perf_event_init();
 590         profile_init();
 591         call_function_init();
 592         WARN(!irqs_disabled(), "Interrupts were enabled early\n");
 593         early_boot_irqs_disabled = false;
 594         local_irq_enable();
 595
 596         kmem_cache_init_late();
 597
 598         /*
 599          * HACK ALERT! This is early. We're enabling the console before
 600          * we've done PCI setups etc, and console_init() must be aware of
 601          * this. But we do want output early, in case something goes wrong.
 602          */
 603         console_init();
 604         if (panic_later)
 605                 panic("Too many boot %s vars at `%s'", panic_later,
 606                       panic_param);
 607
 608         lockdep_info();
 609
 610         /*
 611          * Need to run this when irqs are enabled, because it wants
 612          * to self-test [hard/soft]-irqs on/off lock inversion bugs
 613          * too:
 614          */
 615         locking_selftest();
 616
 617 #ifdef CONFIG_BLK_DEV_INITRD
 618         if (initrd_start && !initrd_below_start_ok &&
 619             page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
 620                 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
 621                     page_to_pfn(virt_to_page((void *)initrd_start)),
 622                     min_low_pfn);
 623                 initrd_start = 0;
 624         }
 625 #endif
 626         page_ext_init();
 627         debug_objects_mem_init();
 628         kmemleak_init();
 629         setup_per_cpu_pageset();
 630         numa_policy_init();
 631         if (late_time_init)
 632                 late_time_init();
 633         sched_clock_init();
 634         calibrate_delay();
 635         pidmap_init();
 636         anon_vma_init();
 637         acpi_early_init();
 638 #ifdef CONFIG_X86
 639         if (efi_enabled(EFI_RUNTIME_SERVICES))
 640                 efi_enter_virtual_mode();
 641 #endif
 642 #ifdef CONFIG_X86_ESPFIX64
 643         /* Should be run before the first non-init thread is created */
 644         init_espfix_bsp();
 645 #endif
 646         thread_info_cache_init();
 647         cred_init();
 648         fork_init(totalram_pages);
 649         proc_caches_init();
 650         buffer_init();
 651         key_init();
 652         security_init();
 653         dbg_late_init();
 654         vfs_caches_init(totalram_pages);
 655         signals_init();
 656         /* rootfs populating might need page-writeback */
 657         page_writeback_init();
 658         proc_root_init();
 659         nsfs_init();
 660         cpuset_init();
 661         cgroup_init();
 662         taskstats_init_early();
 663         delayacct_init();
 664
 665         check_bugs();
 666
 667         sfi_init_late();
 668
 669         if (efi_enabled(EFI_RUNTIME_SERVICES)) {
 670                 efi_late_init();
 671                 efi_free_boot_services();
 672         }
 673
 674         ftrace_init();
 675
 676         /* Do the rest non-__init'ed, we're now alive */
 677         rest_init();
 678 }
 679
 680 /* Call all constructor functions linked into the kernel. */
 681 static void __init do_ctors(void)
 682 {
 683 #ifdef CONFIG_CONSTRUCTORS
 684         ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
 685
 686         for (; fn < (ctor_fn_t *) __ctors_end; fn++)
 687                 (*fn)();
 688 #endif
 689 }
 690
 691 bool initcall_debug;
 692 core_param(initcall_debug, initcall_debug, bool, 0644);
 693
 694 #ifdef CONFIG_KALLSYMS
 695 struct blacklist_entry {
 696         struct list_head next;
 697         char *buf;
 698 };
 699
 700 static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
 701
 702 static int __init initcall_blacklist(char *str)
 703 {
 704         char *str_entry;
 705         struct blacklist_entry *entry;
 706
 707         /* str argument is a comma-separated list of functions */
 708         do {
 709                 str_entry = strsep(&str, ",");
 710                 if (str_entry) {
 711                         pr_debug("blacklisting initcall %s\n", str_entry);
 712                         entry = alloc_bootmem(sizeof(*entry));
 713                         entry->buf = alloc_bootmem(strlen(str_entry) + 1);
 714                         strcpy(entry->buf, str_entry);
 715                         list_add(&entry->next, &blacklisted_initcalls);
 716                 }
 717         } while (str_entry);
 718
 719         return 0;
 720 }
 721
 722 static bool __init_or_module initcall_blacklisted(initcall_t fn)
 723 {
 724         struct list_head *tmp;
 725         struct blacklist_entry *entry;
 726         char *fn_name;
 727
 728         fn_name = kasprintf(GFP_KERNEL, "%pf", fn);
 729         if (!fn_name)
 730                 return false;
 731
 732         list_for_each(tmp, &blacklisted_initcalls) {
 733                 entry = list_entry(tmp, struct blacklist_entry, next);
 734                 if (!strcmp(fn_name, entry->buf)) {
 735                         pr_debug("initcall %s blacklisted\n", fn_name);
 736                         kfree(fn_name);
 737                         return true;
 738                 }
 739         }
 740
 741         kfree(fn_name);
 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         return ret;
 803 }
 804
 805
 806 extern initcall_t __initcall_start[];
 807 extern initcall_t __initcall0_start[];
 808 extern initcall_t __initcall1_start[];
 809 extern initcall_t __initcall2_start[];
 810 extern initcall_t __initcall3_start[];
 811 extern initcall_t __initcall4_start[];
 812 extern initcall_t __initcall5_start[];
 813 extern initcall_t __initcall6_start[];
 814 extern initcall_t __initcall7_start[];
 815 extern initcall_t __initcall_end[];
 816
 817 static initcall_t *initcall_levels[] __initdata = {
 818         __initcall0_start,
 819         __initcall1_start,
 820         __initcall2_start,
 821         __initcall3_start,
 822         __initcall4_start,
 823         __initcall5_start,
 824         __initcall6_start,
 825         __initcall7_start,
 826         __initcall_end,
 827 };
 828
 829 /* Keep these in sync with initcalls in include/linux/init.h */
 830 static char *initcall_level_names[] __initdata = {
 831         "early",
 832         "core",
 833         "postcore",
 834         "arch",
 835         "subsys",
 836         "fs",
 837         "device",
 838         "late",
 839 };
 840
 841 static void __init do_initcall_level(int level)
 842 {
 843         initcall_t *fn;
 844
 845         strcpy(initcall_command_line, saved_command_line);
 846         parse_args(initcall_level_names[level],
 847                    initcall_command_line, __start___param,
 848                    __stop___param - __start___param,
 849                    level, level,
 850                    &repair_env_string);
 851
 852         for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
 853                 do_one_initcall(*fn);
 854 }
 855
 856 static void __init do_initcalls(void)
 857 {
 858         int level;
 859
 860         for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
 861                 do_initcall_level(level);
 862 }
 863
 864 /*
 865  * Ok, the machine is now initialized. None of the devices
 866  * have been touched yet, but the CPU subsystem is up and
 867  * running, and memory and process management works.
 868  *
 869  * Now we can finally start doing some real work..
 870  */
 871 static void __init do_basic_setup(void)
 872 {
 873         cpuset_init_smp();
 874         usermodehelper_init();
 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 static int __ref kernel_init(void *unused)
 928 {
 929         int ret;
 930
 931         kernel_init_freeable();
 932         /* need to finish all async __init code before freeing the memory */
 933         async_synchronize_full();
 934         free_initmem();
 935         mark_rodata_ro();
 936         system_state = SYSTEM_RUNNING;
 937         numa_default_policy();
 938
 939         flush_delayed_fput();
 940
 941         if (ramdisk_execute_command) {
 942                 ret = run_init_process(ramdisk_execute_command);
 943                 if (!ret)
 944                         return 0;
 945                 pr_err("Failed to execute %s (error %d)\n",
 946                        ramdisk_execute_command, ret);
 947         }
 948
 949         /*
 950          * We try each of these until one succeeds.
 951          *
 952          * The Bourne shell can be used instead of init if we are
 953          * trying to recover a really broken machine.
 954          */
 955         if (execute_command) {
 956                 ret = run_init_process(execute_command);
 957                 if (!ret)
 958                         return 0;
 959                 panic("Requested init %s failed (error %d).",
 960                       execute_command, ret);
 961         }
 962         if (!try_to_run_init_process("/sbin/init") ||
 963             !try_to_run_init_process("/etc/init") ||
 964             !try_to_run_init_process("/bin/init") ||
 965             !try_to_run_init_process("/bin/sh"))
 966                 return 0;
 967
 968         panic("No working init found.  Try passing init= option to kernel. "
 969               "See Linux Documentation/init.txt for guidance.");
 970 }
 971
 972 static noinline void __init kernel_init_freeable(void)
 973 {
 974         /*
 975          * Wait until kthreadd is all set-up.
 976          */
 977         wait_for_completion(&kthreadd_done);
 978
 979         /* Now the scheduler is fully set up and can do blocking allocations */
 980         gfp_allowed_mask = __GFP_BITS_MASK;
 981
 982         /*
 983          * init can allocate pages on any node
 984          */
 985         set_mems_allowed(node_states[N_MEMORY]);
 986         /*
 987          * init can run on any cpu.
 988          */
 989         set_cpus_allowed_ptr(current, cpu_all_mask);
 990
 991         cad_pid = task_pid(current);
 992
 993         smp_prepare_cpus(setup_max_cpus);
 994
 995         do_pre_smp_initcalls();
 996         lockup_detector_init();
 997
 998         smp_init();
 999         sched_init_smp();
1000
1001         do_basic_setup();
1002
1003         /* Open the /dev/console on the rootfs, this should never fail */
1004         if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
1005                 pr_err("Warning: unable to open an initial console.\n");
1006
1007         (void) sys_dup(0);
1008         (void) sys_dup(0);
1009         /*
1010          * check if there is an early userspace init.  If yes, let it do all
1011          * the work
1012          */
1013
1014         if (!ramdisk_execute_command)
1015                 ramdisk_execute_command = "/init";
1016
1017         if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
1018                 ramdisk_execute_command = NULL;
1019                 prepare_namespace();
1020         }
1021
1022         /*
1023          * Ok, we have completed the initial bootup, and
1024          * we're essentially up and running. Get rid of the
1025          * initmem segments and start the user-mode stuff..
1026          *
1027          * rootfs is available now, try loading the public keys
1028          * and default modules
1029          */
1030
1031         integrity_load_keys();
1032         load_default_modules();
1033 }