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
  84 #include <asm/io.h>
  85 #include <asm/bugs.h>
  86 #include <asm/setup.h>
  87 #include <asm/sections.h>
  88 #include <asm/cacheflush.h>
  89
  90 #ifdef CONFIG_X86_LOCAL_APIC
  91 #include <asm/smp.h>
  92 #endif
  93
  94 static int kernel_init(void *);
  95
  96 extern void init_IRQ(void);
  97 extern void fork_init(unsigned long);
  98 extern void radix_tree_init(void);
  99 #ifndef CONFIG_DEBUG_RODATA
 100 static inline void mark_rodata_ro(void) { }
 101 #endif
 102
 103 /*
 104  * Debug helper: via this flag we know that we are in 'early bootup code'
 105  * where only the boot processor is running with IRQ disabled.  This means
 106  * two things - IRQ must not be enabled before the flag is cleared and some
 107  * operations which are not allowed with IRQ disabled are allowed while the
 108  * flag is set.
 109  */
 110 bool early_boot_irqs_disabled __read_mostly;
 111
 112 enum system_states system_state __read_mostly;
 113 EXPORT_SYMBOL(system_state);
 114
 115 /*
 116  * Boot command-line arguments
 117  */
 118 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
 119 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
 120
 121 extern void time_init(void);
 122 /* Default late time init is NULL. archs can override this later. */
 123 void (*__initdata late_time_init)(void);
 124
 125 /* Untouched command line saved by arch-specific code. */
 126 char __initdata boot_command_line[COMMAND_LINE_SIZE];
 127 /* Untouched saved command line (eg. for /proc) */
 128 char *saved_command_line;
 129 /* Command line for parameter parsing */
 130 static char *static_command_line;
 131 /* Command line for per-initcall parameter parsing */
 132 static char *initcall_command_line;
 133
 134 static char *execute_command;
 135 static char *ramdisk_execute_command;
 136
 137 /*
 138  * Used to generate warnings if static_key manipulation functions are used
 139  * before jump_label_init is called.
 140  */
 141 bool static_key_initialized __read_mostly;
 142 EXPORT_SYMBOL_GPL(static_key_initialized);
 143
 144 /*
 145  * If set, this is an indication to the drivers that reset the underlying
 146  * device before going ahead with the initialization otherwise driver might
 147  * rely on the BIOS and skip the reset operation.
 148  *
 149  * This is useful if kernel is booting in an unreliable environment.
 150  * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
 151  * skipped and devices will be in unknown state.
 152  */
 153 unsigned int reset_devices;
 154 EXPORT_SYMBOL(reset_devices);
 155
 156 static int __init set_reset_devices(char *str)
 157 {
 158         reset_devices = 1;
 159         return 1;
 160 }
 161
 162 __setup("reset_devices", set_reset_devices);
 163
 164 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 165 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
 166 static const char *panic_later, *panic_param;
 167
 168 extern const struct obs_kernel_param __setup_start[], __setup_end[];
 169
 170 static int __init obsolete_checksetup(char *line)
 171 {
 172         const struct obs_kernel_param *p;
 173         int had_early_param = 0;
 174
 175         p = __setup_start;
 176         do {
 177                 int n = strlen(p->str);
 178                 if (parameqn(line, p->str, n)) {
 179                         if (p->early) {
 180                                 /* Already done in parse_early_param?
 181                                  * (Needs exact match on param part).
 182                                  * Keep iterating, as we can have early
 183                                  * params and __setups of same names 8( */
 184                                 if (line[n] == '\0' || line[n] == '=')
 185                                         had_early_param = 1;
 186                         } else if (!p->setup_func) {
 187                                 pr_warn("Parameter %s is obsolete, ignored\n",
 188                                         p->str);
 189                                 return 1;
 190                         } else if (p->setup_func(line + n))
 191                                 return 1;
 192                 }
 193                 p++;
 194         } while (p < __setup_end);
 195
 196         return had_early_param;
 197 }
 198
 199 /*
 200  * This should be approx 2 Bo*oMips to start (note initial shift), and will
 201  * still work even if initially too large, it will just take slightly longer
 202  */
 203 unsigned long loops_per_jiffy = (1<<12);
 204 EXPORT_SYMBOL(loops_per_jiffy);
 205
 206 static int __init debug_kernel(char *str)
 207 {
 208         console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
 209         return 0;
 210 }
 211
 212 static int __init quiet_kernel(char *str)
 213 {
 214         console_loglevel = CONSOLE_LOGLEVEL_QUIET;
 215         return 0;
 216 }
 217
 218 early_param("debug", debug_kernel);
 219 early_param("quiet", quiet_kernel);
 220
 221 static int __init loglevel(char *str)
 222 {
 223         int newlevel;
 224
 225         /*
 226          * Only update loglevel value when a correct setting was passed,
 227          * to prevent blind crashes (when loglevel being set to 0) that
 228          * are quite hard to debug
 229          */
 230         if (get_option(&str, &newlevel)) {
 231                 console_loglevel = newlevel;
 232                 return 0;
 233         }
 234
 235         return -EINVAL;
 236 }
 237
 238 early_param("loglevel", loglevel);
 239
 240 /* Change NUL term back to "=", to make "param" the whole string. */
 241 static int __init repair_env_string(char *param, char *val, const char *unused)
 242 {
 243         if (val) {
 244                 /* param=val or param="val"? */
 245                 if (val == param+strlen(param)+1)
 246                         val[-1] = '=';
 247                 else if (val == param+strlen(param)+2) {
 248                         val[-2] = '=';
 249                         memmove(val-1, val, strlen(val)+1);
 250                         val--;
 251                 } else
 252                         BUG();
 253         }
 254         return 0;
 255 }
 256
 257 /* Anything after -- gets handed straight to init. */
 258 static int __init set_init_arg(char *param, char *val, const char *unused)
 259 {
 260         unsigned int i;
 261
 262         if (panic_later)
 263                 return 0;
 264
 265         repair_env_string(param, val, unused);
 266
 267         for (i = 0; argv_init[i]; i++) {
 268                 if (i == MAX_INIT_ARGS) {
 269                         panic_later = "init";
 270                         panic_param = param;
 271                         return 0;
 272                 }
 273         }
 274         argv_init[i] = param;
 275         return 0;
 276 }
 277
 278 /*
 279  * Unknown boot options get handed to init, unless they look like
 280  * unused parameters (modprobe will find them in /proc/cmdline).
 281  */
 282 static int __init unknown_bootoption(char *param, char *val, const char *unused)
 283 {
 284         repair_env_string(param, val, unused);
 285
 286         /* Handle obsolete-style parameters */
 287         if (obsolete_checksetup(param))
 288                 return 0;
 289
 290         /* Unused module parameter. */
 291         if (strchr(param, '.') && (!val || strchr(param, '.') < val))
 292                 return 0;
 293
 294         if (panic_later)
 295                 return 0;
 296
 297         if (val) {
 298                 /* Environment option */
 299                 unsigned int i;
 300                 for (i = 0; envp_init[i]; i++) {
 301                         if (i == MAX_INIT_ENVS) {
 302                                 panic_later = "env";
 303                                 panic_param = param;
 304                         }
 305                         if (!strncmp(param, envp_init[i], val - param))
 306                                 break;
 307                 }
 308                 envp_init[i] = param;
 309         } else {
 310                 /* Command line option */
 311                 unsigned int i;
 312                 for (i = 0; argv_init[i]; i++) {
 313                         if (i == MAX_INIT_ARGS) {
 314                                 panic_later = "init";
 315                                 panic_param = param;
 316                         }
 317                 }
 318                 argv_init[i] = param;
 319         }
 320         return 0;
 321 }
 322
 323 static int __init init_setup(char *str)
 324 {
 325         unsigned int i;
 326
 327         execute_command = str;
 328         /*
 329          * In case LILO is going to boot us with default command line,
 330          * it prepends "auto" before the whole cmdline which makes
 331          * the shell think it should execute a script with such name.
 332          * So we ignore all arguments entered _before_ init=... [MJ]
 333          */
 334         for (i = 1; i < MAX_INIT_ARGS; i++)
 335                 argv_init[i] = NULL;
 336         return 1;
 337 }
 338 __setup("init=", init_setup);
 339
 340 static int __init rdinit_setup(char *str)
 341 {
 342         unsigned int i;
 343
 344         ramdisk_execute_command = str;
 345         /* See "auto" comment in init_setup */
 346         for (i = 1; i < MAX_INIT_ARGS; i++)
 347                 argv_init[i] = NULL;
 348         return 1;
 349 }
 350 __setup("rdinit=", rdinit_setup);
 351
 352 #ifndef CONFIG_SMP
 353 static const unsigned int setup_max_cpus = NR_CPUS;
 354 #ifdef CONFIG_X86_LOCAL_APIC
 355 static void __init smp_init(void)
 356 {
 357         APIC_init_uniprocessor();
 358 }
 359 #else
 360 #define smp_init()      do { } while (0)
 361 #endif
 362
 363 static inline void setup_nr_cpu_ids(void) { }
 364 static inline void smp_prepare_cpus(unsigned int maxcpus) { }
 365 #endif
 366
 367 /*
 368  * We need to store the untouched command line for future reference.
 369  * We also need to store the touched command line since the parameter
 370  * parsing is performed in place, and we should allow a component to
 371  * store reference of name/value for future reference.
 372  */
 373 static void __init setup_command_line(char *command_line)
 374 {
 375         saved_command_line =
 376                 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
 377         initcall_command_line =
 378                 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
 379         static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0);
 380         strcpy(saved_command_line, boot_command_line);
 381         strcpy(static_command_line, command_line);
 382 }
 383
 384 /*
 385  * We need to finalize in a non-__init function or else race conditions
 386  * between the root thread and the init thread may cause start_kernel to
 387  * be reaped by free_initmem before the root thread has proceeded to
 388  * cpu_idle.
 389  *
 390  * gcc-3.4 accidentally inlines this function, so use noinline.
 391  */
 392
 393 static __initdata DECLARE_COMPLETION(kthreadd_done);
 394
 395 static noinline void __init_refok rest_init(void)
 396 {
 397         int pid;
 398
 399         rcu_scheduler_starting();
 400         /*
 401          * We need to spawn init first so that it obtains pid 1, however
 402          * the init task will end up wanting to create kthreads, which, if
 403          * we schedule it before we create kthreadd, will OOPS.
 404          */
 405         kernel_thread(kernel_init, NULL, CLONE_FS);
 406         numa_default_policy();
 407         pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
 408         rcu_read_lock();
 409         kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
 410         rcu_read_unlock();
 411         complete(&kthreadd_done);
 412
 413         /*
 414          * The boot idle thread must execute schedule()
 415          * at least once to get things moving:
 416          */
 417         init_idle_bootup_task(current);
 418         schedule_preempt_disabled();
 419         /* Call into cpu_idle with preempt disabled */
 420         cpu_startup_entry(CPUHP_ONLINE);
 421 }
 422
 423 /* Check for early params. */
 424 static int __init do_early_param(char *param, char *val, const char *unused)
 425 {
 426         const struct obs_kernel_param *p;
 427
 428         for (p = __setup_start; p < __setup_end; p++) {
 429                 if ((p->early && parameq(param, p->str)) ||
 430                     (strcmp(param, "console") == 0 &&
 431                      strcmp(p->str, "earlycon") == 0)
 432                 ) {
 433                         if (p->setup_func(val) != 0)
 434                                 pr_warn("Malformed early option '%s'\n", param);
 435                 }
 436         }
 437         /* We accept everything at this stage. */
 438         return 0;
 439 }
 440
 441 void __init parse_early_options(char *cmdline)
 442 {
 443         parse_args("early options", cmdline, NULL, 0, 0, 0, do_early_param);
 444 }
 445
 446 /* Arch code calls this early on, or if not, just before other parsing. */
 447 void __init parse_early_param(void)
 448 {
 449         static int done __initdata;
 450         static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
 451
 452         if (done)
 453                 return;
 454
 455         /* All fall through to do_early_param. */
 456         strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 457         parse_early_options(tmp_cmdline);
 458         done = 1;
 459 }
 460
 461 /*
 462  *      Activate the first processor.
 463  */
 464
 465 static void __init boot_cpu_init(void)
 466 {
 467         int cpu = smp_processor_id();
 468         /* Mark the boot cpu "present", "online" etc for SMP and UP case */
 469         set_cpu_online(cpu, true);
 470         set_cpu_active(cpu, true);
 471         set_cpu_present(cpu, true);
 472         set_cpu_possible(cpu, true);
 473 }
 474
 475 void __init __weak smp_setup_processor_id(void)
 476 {
 477 }
 478
 479 # if THREAD_SIZE >= PAGE_SIZE
 480 void __init __weak thread_info_cache_init(void)
 481 {
 482 }
 483 #endif
 484
 485 /*
 486  * Set up kernel memory allocators
 487  */
 488 static void __init mm_init(void)
 489 {
 490         /*
 491          * page_ext requires contiguous pages,
 492          * bigger than MAX_ORDER unless SPARSEMEM.
 493          */
 494         page_ext_init_flatmem();
 495         mem_init();
 496         kmem_cache_init();
 497         percpu_init_late();
 498         pgtable_init();
 499         vmalloc_init();
 500 }
 501
 502 asmlinkage __visible void __init start_kernel(void)
 503 {
 504         char *command_line;
 505         char *after_dashes;
 506
 507         /*
 508          * Need to run as early as possible, to initialize the
 509          * lockdep hash:
 510          */
 511         lockdep_init();
 512         set_task_stack_end_magic(&init_task);
 513         smp_setup_processor_id();
 514         debug_objects_early_init();
 515
 516         /*
 517          * Set up the the initial canary ASAP:
 518          */
 519         boot_init_stack_canary();
 520
 521         cgroup_init_early();
 522
 523         local_irq_disable();
 524         early_boot_irqs_disabled = true;
 525
 526 /*
 527  * Interrupts are still disabled. Do necessary setups, then
 528  * enable them
 529  */
 530         boot_cpu_init();
 531         page_address_init();
 532         pr_notice("%s", linux_banner);
 533         setup_arch(&command_line);
 534         mm_init_cpumask(&init_mm);
 535         setup_command_line(command_line);
 536         setup_nr_cpu_ids();
 537         setup_per_cpu_areas();
 538         smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
 539
 540         build_all_zonelists(NULL, NULL);
 541         page_alloc_init();
 542
 543         pr_notice("Kernel command line: %s\n", boot_command_line);
 544         parse_early_param();
 545         after_dashes = parse_args("Booting kernel",
 546                                   static_command_line, __start___param,
 547                                   __stop___param - __start___param,
 548                                   -1, -1, &unknown_bootoption);
 549         if (!IS_ERR_OR_NULL(after_dashes))
 550                 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
 551                            set_init_arg);
 552
 553         jump_label_init();
 554
 555         /*
 556          * These use large bootmem allocations and must precede
 557          * kmem_cache_init()
 558          */
 559         setup_log_buf(0);
 560         pidhash_init();
 561         vfs_caches_init_early();
 562         sort_main_extable();
 563         trap_init();
 564         mm_init();
 565
 566         /*
 567          * Set up the scheduler prior starting any interrupts (such as the
 568          * timer interrupt). Full topology setup happens at smp_init()
 569          * time - but meanwhile we still have a functioning scheduler.
 570          */
 571         sched_init();
 572         /*
 573          * Disable preemption - early bootup scheduling is extremely
 574          * fragile until we cpu_idle() for the first time.
 575          */
 576         preempt_disable();
 577         if (WARN(!irqs_disabled(),
 578                  "Interrupts were enabled *very* early, fixing it\n"))
 579                 local_irq_disable();
 580         idr_init_cache();
 581         rcu_init();
 582
 583         /* trace_printk() and trace points may be used after this */
 584         trace_init();
 585
 586         context_tracking_init();
 587         radix_tree_init();
 588         /* init some links before init_ISA_irqs() */
 589         early_irq_init();
 590         init_IRQ();
 591         tick_init();
 592         rcu_init_nohz();
 593         init_timers();
 594         hrtimers_init();
 595         softirq_init();
 596         timekeeping_init();
 597         time_init();
 598         sched_clock_postinit();
 599         perf_event_init();
 600         profile_init();
 601         call_function_init();
 602         WARN(!irqs_disabled(), "Interrupts were enabled early\n");
 603         early_boot_irqs_disabled = false;
 604         local_irq_enable();
 605
 606         kmem_cache_init_late();
 607
 608         /*
 609          * HACK ALERT! This is early. We're enabling the console before
 610          * we've done PCI setups etc, and console_init() must be aware of
 611          * this. But we do want output early, in case something goes wrong.
 612          */
 613         console_init();
 614         if (panic_later)
 615                 panic("Too many boot %s vars at `%s'", panic_later,
 616                       panic_param);
 617
 618         lockdep_info();
 619
 620         /*
 621          * Need to run this when irqs are enabled, because it wants
 622          * to self-test [hard/soft]-irqs on/off lock inversion bugs
 623          * too:
 624          */
 625         locking_selftest();
 626
 627 #ifdef CONFIG_BLK_DEV_INITRD
 628         if (initrd_start && !initrd_below_start_ok &&
 629             page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
 630                 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
 631                     page_to_pfn(virt_to_page((void *)initrd_start)),
 632                     min_low_pfn);
 633                 initrd_start = 0;
 634         }
 635 #endif
 636         page_ext_init();
 637         debug_objects_mem_init();
 638         kmemleak_init();
 639         setup_per_cpu_pageset();
 640         numa_policy_init();
 641         if (late_time_init)
 642                 late_time_init();
 643         sched_clock_init();
 644         calibrate_delay();
 645         pidmap_init();
 646         anon_vma_init();
 647         acpi_early_init();
 648 #ifdef CONFIG_X86
 649         if (efi_enabled(EFI_RUNTIME_SERVICES))
 650                 efi_enter_virtual_mode();
 651 #endif
 652 #ifdef CONFIG_X86_ESPFIX64
 653         /* Should be run before the first non-init thread is created */
 654         init_espfix_bsp();
 655 #endif
 656         thread_info_cache_init();
 657         cred_init();
 658         fork_init(totalram_pages);
 659         proc_caches_init();
 660         buffer_init();
 661         key_init();
 662         security_init();
 663         dbg_late_init();
 664         vfs_caches_init(totalram_pages);
 665         signals_init();
 666         /* rootfs populating might need page-writeback */
 667         page_writeback_init();
 668         proc_root_init();
 669         nsfs_init();
 670         cgroup_init();
 671         cpuset_init();
 672         taskstats_init_early();
 673         delayacct_init();
 674
 675         check_bugs();
 676
 677         sfi_init_late();
 678
 679         if (efi_enabled(EFI_RUNTIME_SERVICES)) {
 680                 efi_late_init();
 681                 efi_free_boot_services();
 682         }
 683
 684         ftrace_init();
 685
 686         /* Do the rest non-__init'ed, we're now alive */
 687         rest_init();
 688 }
 689
 690 /* Call all constructor functions linked into the kernel. */
 691 static void __init do_ctors(void)
 692 {
 693 #ifdef CONFIG_CONSTRUCTORS
 694         ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
 695
 696         for (; fn < (ctor_fn_t *) __ctors_end; fn++)
 697                 (*fn)();
 698 #endif
 699 }
 700
 701 bool initcall_debug;
 702 core_param(initcall_debug, initcall_debug, bool, 0644);
 703
 704 #ifdef CONFIG_KALLSYMS
 705 struct blacklist_entry {
 706         struct list_head next;
 707         char *buf;
 708 };
 709
 710 static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
 711
 712 static int __init initcall_blacklist(char *str)
 713 {
 714         char *str_entry;
 715         struct blacklist_entry *entry;
 716
 717         /* str argument is a comma-separated list of functions */
 718         do {
 719                 str_entry = strsep(&str, ",");
 720                 if (str_entry) {
 721                         pr_debug("blacklisting initcall %s\n", str_entry);
 722                         entry = alloc_bootmem(sizeof(*entry));
 723                         entry->buf = alloc_bootmem(strlen(str_entry) + 1);
 724                         strcpy(entry->buf, str_entry);
 725                         list_add(&entry->next, &blacklisted_initcalls);
 726                 }
 727         } while (str_entry);
 728
 729         return 0;
 730 }
 731
 732 static bool __init_or_module initcall_blacklisted(initcall_t fn)
 733 {
 734         struct list_head *tmp;
 735         struct blacklist_entry *entry;
 736         char *fn_name;
 737
 738         fn_name = kasprintf(GFP_KERNEL, "%pf", fn);
 739         if (!fn_name)
 740                 return false;
 741
 742         list_for_each(tmp, &blacklisted_initcalls) {
 743                 entry = list_entry(tmp, struct blacklist_entry, next);
 744                 if (!strcmp(fn_name, entry->buf)) {
 745                         pr_debug("initcall %s blacklisted\n", fn_name);
 746                         kfree(fn_name);
 747                         return true;
 748                 }
 749         }
 750
 751         kfree(fn_name);
 752         return false;
 753 }
 754 #else
 755 static int __init initcall_blacklist(char *str)
 756 {
 757         pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
 758         return 0;
 759 }
 760
 761 static bool __init_or_module initcall_blacklisted(initcall_t fn)
 762 {
 763         return false;
 764 }
 765 #endif
 766 __setup("initcall_blacklist=", initcall_blacklist);
 767
 768 static int __init_or_module do_one_initcall_debug(initcall_t fn)
 769 {
 770         ktime_t calltime, delta, rettime;
 771         unsigned long long duration;
 772         int ret;
 773
 774         printk(KERN_DEBUG "calling  %pF @ %i\n", fn, task_pid_nr(current));
 775         calltime = ktime_get();
 776         ret = fn();
 777         rettime = ktime_get();
 778         delta = ktime_sub(rettime, calltime);
 779         duration = (unsigned long long) ktime_to_ns(delta) >> 10;
 780         printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n",
 781                  fn, ret, duration);
 782
 783         return ret;
 784 }
 785
 786 int __init_or_module do_one_initcall(initcall_t fn)
 787 {
 788         int count = preempt_count();
 789         int ret;
 790         char msgbuf[64];
 791
 792         if (initcall_blacklisted(fn))
 793                 return -EPERM;
 794
 795         if (initcall_debug)
 796                 ret = do_one_initcall_debug(fn);
 797         else
 798                 ret = fn();
 799
 800         msgbuf[0] = 0;
 801
 802         if (preempt_count() != count) {
 803                 sprintf(msgbuf, "preemption imbalance ");
 804                 preempt_count_set(count);
 805         }
 806         if (irqs_disabled()) {
 807                 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
 808                 local_irq_enable();
 809         }
 810         WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
 811
 812         return ret;
 813 }
 814
 815
 816 extern initcall_t __initcall_start[];
 817 extern initcall_t __initcall0_start[];
 818 extern initcall_t __initcall1_start[];
 819 extern initcall_t __initcall2_start[];
 820 extern initcall_t __initcall3_start[];
 821 extern initcall_t __initcall4_start[];
 822 extern initcall_t __initcall5_start[];
 823 extern initcall_t __initcall6_start[];
 824 extern initcall_t __initcall7_start[];
 825 extern initcall_t __initcall_end[];
 826
 827 static initcall_t *initcall_levels[] __initdata = {
 828         __initcall0_start,
 829         __initcall1_start,
 830         __initcall2_start,
 831         __initcall3_start,
 832         __initcall4_start,
 833         __initcall5_start,
 834         __initcall6_start,
 835         __initcall7_start,
 836         __initcall_end,
 837 };
 838
 839 /* Keep these in sync with initcalls in include/linux/init.h */
 840 static char *initcall_level_names[] __initdata = {
 841         "early",
 842         "core",
 843         "postcore",
 844         "arch",
 845         "subsys",
 846         "fs",
 847         "device",
 848         "late",
 849 };
 850
 851 static void __init do_initcall_level(int level)
 852 {
 853         initcall_t *fn;
 854
 855         strcpy(initcall_command_line, saved_command_line);
 856         parse_args(initcall_level_names[level],
 857                    initcall_command_line, __start___param,
 858                    __stop___param - __start___param,
 859                    level, level,
 860                    &repair_env_string);
 861
 862         for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
 863                 do_one_initcall(*fn);
 864 }
 865
 866 static void __init do_initcalls(void)
 867 {
 868         int level;
 869
 870         for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
 871                 do_initcall_level(level);
 872 }
 873
 874 /*
 875  * Ok, the machine is now initialized. None of the devices
 876  * have been touched yet, but the CPU subsystem is up and
 877  * running, and memory and process management works.
 878  *
 879  * Now we can finally start doing some real work..
 880  */
 881 static void __init do_basic_setup(void)
 882 {
 883         cpuset_init_smp();
 884         usermodehelper_init();
 885         shmem_init();
 886         driver_init();
 887         init_irq_proc();
 888         do_ctors();
 889         usermodehelper_enable();
 890         do_initcalls();
 891         random_int_secret_init();
 892 }
 893
 894 static void __init do_pre_smp_initcalls(void)
 895 {
 896         initcall_t *fn;
 897
 898         for (fn = __initcall_start; fn < __initcall0_start; fn++)
 899                 do_one_initcall(*fn);
 900 }
 901
 902 /*
 903  * This function requests modules which should be loaded by default and is
 904  * called twice right after initrd is mounted and right before init is
 905  * exec'd.  If such modules are on either initrd or rootfs, they will be
 906  * loaded before control is passed to userland.
 907  */
 908 void __init load_default_modules(void)
 909 {
 910         load_default_elevator_module();
 911 }
 912
 913 static int run_init_process(const char *init_filename)
 914 {
 915         argv_init[0] = init_filename;
 916         return do_execve(getname_kernel(init_filename),
 917                 (const char __user *const __user *)argv_init,
 918                 (const char __user *const __user *)envp_init);
 919 }
 920
 921 static int try_to_run_init_process(const char *init_filename)
 922 {
 923         int ret;
 924
 925         ret = run_init_process(init_filename);
 926
 927         if (ret && ret != -ENOENT) {
 928                 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
 929                        init_filename, ret);
 930         }
 931
 932         return ret;
 933 }
 934
 935 static noinline void __init kernel_init_freeable(void);
 936
 937 static int __ref kernel_init(void *unused)
 938 {
 939         int ret;
 940
 941         kernel_init_freeable();
 942         /* need to finish all async __init code before freeing the memory */
 943         async_synchronize_full();
 944         free_initmem();
 945         mark_rodata_ro();
 946         system_state = SYSTEM_RUNNING;
 947         numa_default_policy();
 948
 949         flush_delayed_fput();
 950
 951         if (ramdisk_execute_command) {
 952                 ret = run_init_process(ramdisk_execute_command);
 953                 if (!ret)
 954                         return 0;
 955                 pr_err("Failed to execute %s (error %d)\n",
 956                        ramdisk_execute_command, ret);
 957         }
 958
 959         /*
 960          * We try each of these until one succeeds.
 961          *
 962          * The Bourne shell can be used instead of init if we are
 963          * trying to recover a really broken machine.
 964          */
 965         if (execute_command) {
 966                 ret = run_init_process(execute_command);
 967                 if (!ret)
 968                         return 0;
 969 #ifndef CONFIG_INIT_FALLBACK
 970                 panic("Requested init %s failed (error %d).",
 971                       execute_command, ret);
 972 #else
 973                 pr_err("Failed to execute %s (error %d).  Attempting defaults...\n",
 974                        execute_command, ret);
 975 #endif
 976         }
 977         if (!try_to_run_init_process("/sbin/init") ||
 978             !try_to_run_init_process("/etc/init") ||
 979             !try_to_run_init_process("/bin/init") ||
 980             !try_to_run_init_process("/bin/sh"))
 981                 return 0;
 982
 983         panic("No working init found.  Try passing init= option to kernel. "
 984               "See Linux Documentation/init.txt for guidance.");
 985 }
 986
 987 static noinline void __init kernel_init_freeable(void)
 988 {
 989         /*
 990          * Wait until kthreadd is all set-up.
 991          */
 992         wait_for_completion(&kthreadd_done);
 993
 994         /* Now the scheduler is fully set up and can do blocking allocations */
 995         gfp_allowed_mask = __GFP_BITS_MASK;
 996
 997         /*
 998          * init can allocate pages on any node
 999          */
1000         set_mems_allowed(node_states[N_MEMORY]);
1001         /*
1002          * init can run on any cpu.
1003          */
1004         set_cpus_allowed_ptr(current, cpu_all_mask);
1005
1006         cad_pid = task_pid(current);
1007
1008         smp_prepare_cpus(setup_max_cpus);
1009
1010         do_pre_smp_initcalls();
1011         lockup_detector_init();
1012
1013         smp_init();
1014         sched_init_smp();
1015
1016         do_basic_setup();
1017
1018         /* Open the /dev/console on the rootfs, this should never fail */
1019         if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
1020                 pr_err("Warning: unable to open an initial console.\n");
1021
1022         (void) sys_dup(0);
1023         (void) sys_dup(0);
1024         /*
1025          * check if there is an early userspace init.  If yes, let it do all
1026          * the work
1027          */
1028
1029         if (!ramdisk_execute_command)
1030                 ramdisk_execute_command = "/init";
1031
1032         if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
1033                 ramdisk_execute_command = NULL;
1034                 prepare_namespace();
1035         }
1036
1037         /*
1038          * Ok, we have completed the initial bootup, and
1039          * we're essentially up and running. Get rid of the
1040          * initmem segments and start the user-mode stuff..
1041          *
1042          * rootfs is available now, try loading the public keys
1043          * and default modules
1044          */
1045
1046         integrity_load_keys();
1047         load_default_modules();
1048 }