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(void);
  95 extern void radix_tree_init(void);
  96
  97 /*
  98  * Debug helper: via this flag we know that we are in 'early bootup code'
  99  * where only the boot processor is running with IRQ disabled.  This means
 100  * two things - IRQ must not be enabled before the flag is cleared and some
 101  * operations which are not allowed with IRQ disabled are allowed while the
 102  * flag is set.
 103  */
 104 bool early_boot_irqs_disabled __read_mostly;
 105
 106 enum system_states system_state __read_mostly;
 107 EXPORT_SYMBOL(system_state);
 108
 109 /*
 110  * Boot command-line arguments
 111  */
 112 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
 113 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
 114
 115 extern void time_init(void);
 116 /* Default late time init is NULL. archs can override this later. */
 117 void (*__initdata late_time_init)(void);
 118
 119 /* Untouched command line saved by arch-specific code. */
 120 char __initdata boot_command_line[COMMAND_LINE_SIZE];
 121 /* Untouched saved command line (eg. for /proc) */
 122 char *saved_command_line;
 123 /* Command line for parameter parsing */
 124 static char *static_command_line;
 125 /* Command line for per-initcall parameter parsing */
 126 static char *initcall_command_line;
 127
 128 static char *execute_command;
 129 static char *ramdisk_execute_command;
 130
 131 /*
 132  * Used to generate warnings if static_key manipulation functions are used
 133  * before jump_label_init is called.
 134  */
 135 bool static_key_initialized __read_mostly;
 136 EXPORT_SYMBOL_GPL(static_key_initialized);
 137
 138 /*
 139  * If set, this is an indication to the drivers that reset the underlying
 140  * device before going ahead with the initialization otherwise driver might
 141  * rely on the BIOS and skip the reset operation.
 142  *
 143  * This is useful if kernel is booting in an unreliable environment.
 144  * For ex. kdump situation where previous kernel has crashed, BIOS has been
 145  * skipped and devices will be in unknown state.
 146  */
 147 unsigned int reset_devices;
 148 EXPORT_SYMBOL(reset_devices);
 149
 150 static int __init set_reset_devices(char *str)
 151 {
 152         reset_devices = 1;
 153         return 1;
 154 }
 155
 156 __setup("reset_devices", set_reset_devices);
 157
 158 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 159 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
 160 static const char *panic_later, *panic_param;
 161
 162 extern const struct obs_kernel_param __setup_start[], __setup_end[];
 163
 164 static int __init obsolete_checksetup(char *line)
 165 {
 166         const struct obs_kernel_param *p;
 167         int had_early_param = 0;
 168
 169         p = __setup_start;
 170         do {
 171                 int n = strlen(p->str);
 172                 if (parameqn(line, p->str, n)) {
 173                         if (p->early) {
 174                                 /* Already done in parse_early_param?
 175                                  * (Needs exact match on param part).
 176                                  * Keep iterating, as we can have early
 177                                  * params and __setups of same names 8( */
 178                                 if (line[n] == '\0' || line[n] == '=')
 179                                         had_early_param = 1;
 180                         } else if (!p->setup_func) {
 181                                 pr_warn("Parameter %s is obsolete, ignored\n",
 182                                         p->str);
 183                                 return 1;
 184                         } else if (p->setup_func(line + n))
 185                                 return 1;
 186                 }
 187                 p++;
 188         } while (p < __setup_end);
 189
 190         return had_early_param;
 191 }
 192
 193 /*
 194  * This should be approx 2 Bo*oMips to start (note initial shift), and will
 195  * still work even if initially too large, it will just take slightly longer
 196  */
 197 unsigned long loops_per_jiffy = (1<<12);
 198 EXPORT_SYMBOL(loops_per_jiffy);
 199
 200 static int __init debug_kernel(char *str)
 201 {
 202         console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
 203         return 0;
 204 }
 205
 206 static int __init quiet_kernel(char *str)
 207 {
 208         console_loglevel = CONSOLE_LOGLEVEL_QUIET;
 209         return 0;
 210 }
 211
 212 early_param("debug", debug_kernel);
 213 early_param("quiet", quiet_kernel);
 214
 215 static int __init loglevel(char *str)
 216 {
 217         int newlevel;
 218
 219         /*
 220          * Only update loglevel value when a correct setting was passed,
 221          * to prevent blind crashes (when loglevel being set to 0) that
 222          * are quite hard to debug
 223          */
 224         if (get_option(&str, &newlevel)) {
 225                 console_loglevel = newlevel;
 226                 return 0;
 227         }
 228
 229         return -EINVAL;
 230 }
 231
 232 early_param("loglevel", loglevel);
 233
 234 /* Change NUL term back to "=", to make "param" the whole string. */
 235 static int __init repair_env_string(char *param, char *val,
 236                                     const char *unused, void *arg)
 237 {
 238         if (val) {
 239                 /* param=val or param="val"? */
 240                 if (val == param+strlen(param)+1)
 241                         val[-1] = '=';
 242                 else if (val == param+strlen(param)+2) {
 243                         val[-2] = '=';
 244                         memmove(val-1, val, strlen(val)+1);
 245                         val--;
 246                 } else
 247                         BUG();
 248         }
 249         return 0;
 250 }
 251
 252 /* Anything after -- gets handed straight to init. */
 253 static int __init set_init_arg(char *param, char *val,
 254                                const char *unused, void *arg)
 255 {
 256         unsigned int i;
 257
 258         if (panic_later)
 259                 return 0;
 260
 261         repair_env_string(param, val, unused, NULL);
 262
 263         for (i = 0; argv_init[i]; i++) {
 264                 if (i == MAX_INIT_ARGS) {
 265                         panic_later = "init";
 266                         panic_param = param;
 267                         return 0;
 268                 }
 269         }
 270         argv_init[i] = param;
 271         return 0;
 272 }
 273
 274 /*
 275  * Unknown boot options get handed to init, unless they look like
 276  * unused parameters (modprobe will find them in /proc/cmdline).
 277  */
 278 static int __init unknown_bootoption(char *param, char *val,
 279                                      const char *unused, void *arg)
 280 {
 281         repair_env_string(param, val, unused, NULL);
 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,
 414                                  const char *unused, void *arg)
 415 {
 416         const struct obs_kernel_param *p;
 417
 418         for (p = __setup_start; p < __setup_end; p++) {
 419                 if ((p->early && parameq(param, p->str)) ||
 420                     (strcmp(param, "console") == 0 &&
 421                      strcmp(p->str, "earlycon") == 0)
 422                 ) {
 423                         if (p->setup_func(val) != 0)
 424                                 pr_warn("Malformed early option '%s'\n", param);
 425                 }
 426         }
 427         /* We accept everything at this stage. */
 428         return 0;
 429 }
 430
 431 void __init parse_early_options(char *cmdline)
 432 {
 433         parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
 434                    do_early_param);
 435 }
 436
 437 /* Arch code calls this early on, or if not, just before other parsing. */
 438 void __init parse_early_param(void)
 439 {
 440         static int done __initdata;
 441         static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
 442
 443         if (done)
 444                 return;
 445
 446         /* All fall through to do_early_param. */
 447         strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 448         parse_early_options(tmp_cmdline);
 449         done = 1;
 450 }
 451
 452 /*
 453  *      Activate the first processor.
 454  */
 455
 456 static void __init boot_cpu_init(void)
 457 {
 458         int cpu = smp_processor_id();
 459         /* Mark the boot cpu "present", "online" etc for SMP and UP case */
 460         set_cpu_online(cpu, true);
 461         set_cpu_active(cpu, true);
 462         set_cpu_present(cpu, true);
 463         set_cpu_possible(cpu, true);
 464 }
 465
 466 void __init __weak smp_setup_processor_id(void)
 467 {
 468 }
 469
 470 # if THREAD_SIZE >= PAGE_SIZE
 471 void __init __weak thread_stack_cache_init(void)
 472 {
 473 }
 474 #endif
 475
 476 /*
 477  * Set up kernel memory allocators
 478  */
 479 static void __init mm_init(void)
 480 {
 481         /*
 482          * page_ext requires contiguous pages,
 483          * bigger than MAX_ORDER unless SPARSEMEM.
 484          */
 485         page_ext_init_flatmem();
 486         mem_init();
 487         kmem_cache_init();
 488         percpu_init_late();
 489         pgtable_init();
 490         vmalloc_init();
 491         ioremap_huge_init();
 492 }
 493
 494 asmlinkage __visible void __init start_kernel(void)
 495 {
 496         char *command_line;
 497         char *after_dashes;
 498
 499         /*
 500          * Need to run as early as possible, to initialize the
 501          * lockdep hash:
 502          */
 503         lockdep_init();
 504         set_task_stack_end_magic(&init_task);
 505         smp_setup_processor_id();
 506         debug_objects_early_init();
 507
 508         /*
 509          * Set up the the initial canary ASAP:
 510          */
 511         boot_init_stack_canary();
 512
 513         cgroup_init_early();
 514
 515         local_irq_disable();
 516         early_boot_irqs_disabled = true;
 517
 518 /*
 519  * Interrupts are still disabled. Do necessary setups, then
 520  * enable them
 521  */
 522         boot_cpu_init();
 523         page_address_init();
 524         pr_notice("%s", linux_banner);
 525         setup_arch(&command_line);
 526         mm_init_cpumask(&init_mm);
 527         setup_command_line(command_line);
 528         setup_nr_cpu_ids();
 529         setup_per_cpu_areas();
 530         smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
 531
 532         build_all_zonelists(NULL, NULL);
 533         page_alloc_init();
 534
 535         pr_notice("Kernel command line: %s\n", boot_command_line);
 536         parse_early_param();
 537         after_dashes = parse_args("Booting kernel",
 538                                   static_command_line, __start___param,
 539                                   __stop___param - __start___param,
 540                                   -1, -1, NULL, &unknown_bootoption);
 541         if (!IS_ERR_OR_NULL(after_dashes))
 542                 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
 543                            NULL, set_init_arg);
 544
 545         jump_label_init();
 546
 547         /*
 548          * These use large bootmem allocations and must precede
 549          * kmem_cache_init()
 550          */
 551         setup_log_buf(0);
 552         pidhash_init();
 553         vfs_caches_init_early();
 554         sort_main_extable();
 555         trap_init();
 556         mm_init();
 557
 558         /*
 559          * Set up the scheduler prior starting any interrupts (such as the
 560          * timer interrupt). Full topology setup happens at smp_init()
 561          * time - but meanwhile we still have a functioning scheduler.
 562          */
 563         sched_init();
 564         /*
 565          * Disable preemption - early bootup scheduling is extremely
 566          * fragile until we cpu_idle() for the first time.
 567          */
 568         preempt_disable();
 569         if (WARN(!irqs_disabled(),
 570                  "Interrupts were enabled *very* early, fixing it\n"))
 571                 local_irq_disable();
 572         idr_init_cache();
 573         rcu_init();
 574
 575         /* trace_printk() and trace points may be used after this */
 576         trace_init();
 577
 578         context_tracking_init();
 579         radix_tree_init();
 580         /* init some links before init_ISA_irqs() */
 581         early_irq_init();
 582         init_IRQ();
 583         tick_init();
 584         rcu_init_nohz();
 585         init_timers();
 586         hrtimers_init();
 587         softirq_init();
 588         timekeeping_init();
 589         time_init();
 590         sched_clock_postinit();
 591         perf_event_init();
 592         profile_init();
 593         call_function_init();
 594         WARN(!irqs_disabled(), "Interrupts were enabled early\n");
 595         early_boot_irqs_disabled = false;
 596         local_irq_enable();
 597
 598         kmem_cache_init_late();
 599
 600         /*
 601          * HACK ALERT! This is early. We're enabling the console before
 602          * we've done PCI setups etc, and console_init() must be aware of
 603          * this. But we do want output early, in case something goes wrong.
 604          */
 605         console_init();
 606         if (panic_later)
 607                 panic("Too many boot %s vars at `%s'", panic_later,
 608                       panic_param);
 609
 610         lockdep_info();
 611
 612         /*
 613          * Need to run this when irqs are enabled, because it wants
 614          * to self-test [hard/soft]-irqs on/off lock inversion bugs
 615          * too:
 616          */
 617         locking_selftest();
 618
 619 #ifdef CONFIG_BLK_DEV_INITRD
 620         if (initrd_start && !initrd_below_start_ok &&
 621             page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
 622                 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
 623                     page_to_pfn(virt_to_page((void *)initrd_start)),
 624                     min_low_pfn);
 625                 initrd_start = 0;
 626         }
 627 #endif
 628         page_ext_init();
 629         debug_objects_mem_init();
 630         kmemleak_init();
 631         setup_per_cpu_pageset();
 632         numa_policy_init();
 633         if (late_time_init)
 634                 late_time_init();
 635         sched_clock_init();
 636         calibrate_delay();
 637         pidmap_init();
 638         anon_vma_init();
 639         acpi_early_init();
 640 #ifdef CONFIG_X86
 641         if (efi_enabled(EFI_RUNTIME_SERVICES))
 642                 efi_enter_virtual_mode();
 643 #endif
 644 #ifdef CONFIG_X86_ESPFIX64
 645         /* Should be run before the first non-init thread is created */
 646         init_espfix_bsp();
 647 #endif
 648         thread_stack_cache_init();
 649         cred_init();
 650         fork_init();
 651         proc_caches_init();
 652         buffer_init();
 653         key_init();
 654         security_init();
 655         dbg_late_init();
 656         vfs_caches_init();
 657         signals_init();
 658         /* rootfs populating might need page-writeback */
 659         page_writeback_init();
 660         proc_root_init();
 661         nsfs_init();
 662         cpuset_init();
 663         cgroup_init();
 664         taskstats_init_early();
 665         delayacct_init();
 666
 667         check_bugs();
 668
 669         acpi_subsystem_init();
 670         sfi_init_late();
 671
 672         if (efi_enabled(EFI_RUNTIME_SERVICES)) {
 673                 efi_late_init();
 674                 efi_free_boot_services();
 675         }
 676
 677         ftrace_init();
 678
 679         /* Do the rest non-__init'ed, we're now alive */
 680         rest_init();
 681 }
 682
 683 /* Call all constructor functions linked into the kernel. */
 684 static void __init do_ctors(void)
 685 {
 686 #ifdef CONFIG_CONSTRUCTORS
 687         ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
 688
 689         for (; fn < (ctor_fn_t *) __ctors_end; fn++)
 690                 (*fn)();
 691 #endif
 692 }
 693
 694 bool initcall_debug;
 695 core_param(initcall_debug, initcall_debug, bool, 0644);
 696
 697 #ifdef CONFIG_KALLSYMS
 698 struct blacklist_entry {
 699         struct list_head next;
 700         char *buf;
 701 };
 702
 703 static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
 704
 705 static int __init initcall_blacklist(char *str)
 706 {
 707         char *str_entry;
 708         struct blacklist_entry *entry;
 709
 710         /* str argument is a comma-separated list of functions */
 711         do {
 712                 str_entry = strsep(&str, ",");
 713                 if (str_entry) {
 714                         pr_debug("blacklisting initcall %s\n", str_entry);
 715                         entry = alloc_bootmem(sizeof(*entry));
 716                         entry->buf = alloc_bootmem(strlen(str_entry) + 1);
 717                         strcpy(entry->buf, str_entry);
 718                         list_add(&entry->next, &blacklisted_initcalls);
 719                 }
 720         } while (str_entry);
 721
 722         return 0;
 723 }
 724
 725 static bool __init_or_module initcall_blacklisted(initcall_t fn)
 726 {
 727         struct list_head *tmp;
 728         struct blacklist_entry *entry;
 729         char *fn_name;
 730
 731         fn_name = kasprintf(GFP_KERNEL, "%pf", fn);
 732         if (!fn_name)
 733                 return false;
 734
 735         list_for_each(tmp, &blacklisted_initcalls) {
 736                 entry = list_entry(tmp, struct blacklist_entry, next);
 737                 if (!strcmp(fn_name, entry->buf)) {
 738                         pr_debug("initcall %s blacklisted\n", fn_name);
 739                         kfree(fn_name);
 740                         return true;
 741                 }
 742         }
 743
 744         kfree(fn_name);
 745         return false;
 746 }
 747 #else
 748 static int __init initcall_blacklist(char *str)
 749 {
 750         pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
 751         return 0;
 752 }
 753
 754 static bool __init_or_module initcall_blacklisted(initcall_t fn)
 755 {
 756         return false;
 757 }
 758 #endif
 759 __setup("initcall_blacklist=", initcall_blacklist);
 760
 761 static int __init_or_module do_one_initcall_debug(initcall_t fn)
 762 {
 763         ktime_t calltime, delta, rettime;
 764         unsigned long long duration;
 765         int ret;
 766
 767         printk(KERN_DEBUG "calling  %pF @ %i\n", fn, task_pid_nr(current));
 768         calltime = ktime_get();
 769         ret = fn();
 770         rettime = ktime_get();
 771         delta = ktime_sub(rettime, calltime);
 772         duration = (unsigned long long) ktime_to_ns(delta) >> 10;
 773         printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n",
 774                  fn, ret, duration);
 775
 776         return ret;
 777 }
 778
 779 int __init_or_module do_one_initcall(initcall_t fn)
 780 {
 781         int count = preempt_count();
 782         int ret;
 783         char msgbuf[64];
 784
 785         if (initcall_blacklisted(fn))
 786                 return -EPERM;
 787
 788         if (initcall_debug)
 789                 ret = do_one_initcall_debug(fn);
 790         else
 791                 ret = fn();
 792
 793         msgbuf[0] = 0;
 794
 795         if (preempt_count() != count) {
 796                 sprintf(msgbuf, "preemption imbalance ");
 797                 preempt_count_set(count);
 798         }
 799         if (irqs_disabled()) {
 800                 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
 801                 local_irq_enable();
 802         }
 803         WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
 804
 805         return ret;
 806 }
 807
 808
 809 extern initcall_t __initcall_start[];
 810 extern initcall_t __initcall0_start[];
 811 extern initcall_t __initcall1_start[];
 812 extern initcall_t __initcall2_start[];
 813 extern initcall_t __initcall3_start[];
 814 extern initcall_t __initcall4_start[];
 815 extern initcall_t __initcall5_start[];
 816 extern initcall_t __initcall6_start[];
 817 extern initcall_t __initcall7_start[];
 818 extern initcall_t __initcall_end[];
 819
 820 static initcall_t *initcall_levels[] __initdata = {
 821         __initcall0_start,
 822         __initcall1_start,
 823         __initcall2_start,
 824         __initcall3_start,
 825         __initcall4_start,
 826         __initcall5_start,
 827         __initcall6_start,
 828         __initcall7_start,
 829         __initcall_end,
 830 };
 831
 832 /* Keep these in sync with initcalls in include/linux/init.h */
 833 static char *initcall_level_names[] __initdata = {
 834         "early",
 835         "core",
 836         "postcore",
 837         "arch",
 838         "subsys",
 839         "fs",
 840         "device",
 841         "late",
 842 };
 843
 844 static void __init do_initcall_level(int level)
 845 {
 846         initcall_t *fn;
 847
 848         strcpy(initcall_command_line, saved_command_line);
 849         parse_args(initcall_level_names[level],
 850                    initcall_command_line, __start___param,
 851                    __stop___param - __start___param,
 852                    level, level,
 853                    NULL, &repair_env_string);
 854
 855         for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
 856                 do_one_initcall(*fn);
 857 }
 858
 859 static void __init do_initcalls(void)
 860 {
 861         int level;
 862
 863         for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
 864                 do_initcall_level(level);
 865 }
 866
 867 /*
 868  * Ok, the machine is now initialized. None of the devices
 869  * have been touched yet, but the CPU subsystem is up and
 870  * running, and memory and process management works.
 871  *
 872  * Now we can finally start doing some real work..
 873  */
 874 static void __init do_basic_setup(void)
 875 {
 876         cpuset_init_smp();
 877         shmem_init();
 878         driver_init();
 879         init_irq_proc();
 880         do_ctors();
 881         usermodehelper_enable();
 882         do_initcalls();
 883         random_int_secret_init();
 884 }
 885
 886 static void __init do_pre_smp_initcalls(void)
 887 {
 888         initcall_t *fn;
 889
 890         for (fn = __initcall_start; fn < __initcall0_start; fn++)
 891                 do_one_initcall(*fn);
 892 }
 893
 894 /*
 895  * This function requests modules which should be loaded by default and is
 896  * called twice right after initrd is mounted and right before init is
 897  * exec'd.  If such modules are on either initrd or rootfs, they will be
 898  * loaded before control is passed to userland.
 899  */
 900 void __init load_default_modules(void)
 901 {
 902         load_default_elevator_module();
 903 }
 904
 905 static int run_init_process(const char *init_filename)
 906 {
 907         argv_init[0] = init_filename;
 908         return do_execve(getname_kernel(init_filename),
 909                 (const char __user *const __user *)argv_init,
 910                 (const char __user *const __user *)envp_init);
 911 }
 912
 913 static int try_to_run_init_process(const char *init_filename)
 914 {
 915         int ret;
 916
 917         ret = run_init_process(init_filename);
 918
 919         if (ret && ret != -ENOENT) {
 920                 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
 921                        init_filename, ret);
 922         }
 923
 924         return ret;
 925 }
 926
 927 static noinline void __init kernel_init_freeable(void);
 928
 929 #ifdef CONFIG_DEBUG_RODATA
 930 static bool rodata_enabled = true;
 931 static int __init set_debug_rodata(char *str)
 932 {
 933         return strtobool(str, &rodata_enabled);
 934 }
 935 __setup("rodata=", set_debug_rodata);
 936
 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         if (ramdisk_execute_command) {
 966                 ret = run_init_process(ramdisk_execute_command);
 967                 if (!ret)
 968                         return 0;
 969                 pr_err("Failed to execute %s (error %d)\n",
 970                        ramdisk_execute_command, ret);
 971         }
 972
 973         /*
 974          * We try each of these until one succeeds.
 975          *
 976          * The Bourne shell can be used instead of init if we are
 977          * trying to recover a really broken machine.
 978          */
 979         if (execute_command) {
 980                 ret = run_init_process(execute_command);
 981                 if (!ret)
 982                         return 0;
 983                 panic("Requested init %s failed (error %d).",
 984                       execute_command, ret);
 985         }
 986         if (!try_to_run_init_process("/sbin/init") ||
 987             !try_to_run_init_process("/etc/init") ||
 988             !try_to_run_init_process("/bin/init") ||
 989             !try_to_run_init_process("/bin/sh"))
 990                 return 0;
 991
 992         panic("No working init found.  Try passing init= option to kernel. "
 993               "See Linux Documentation/init.txt for guidance.");
 994 }
 995
 996 static noinline void __init kernel_init_freeable(void)
 997 {
 998         /*
 999          * Wait until kthreadd is all set-up.
1000          */
1001         wait_for_completion(&kthreadd_done);
1002
1003         /* Now the scheduler is fully set up and can do blocking allocations */
1004         gfp_allowed_mask = __GFP_BITS_MASK;
1005
1006         /*
1007          * init can allocate pages on any node
1008          */
1009         set_mems_allowed(node_states[N_MEMORY]);
1010         /*
1011          * init can run on any cpu.
1012          */
1013         set_cpus_allowed_ptr(current, cpu_all_mask);
1014
1015         cad_pid = task_pid(current);
1016
1017         smp_prepare_cpus(setup_max_cpus);
1018
1019         do_pre_smp_initcalls();
1020         lockup_detector_init();
1021
1022         smp_init();
1023         sched_init_smp();
1024
1025         page_alloc_init_late();
1026
1027         do_basic_setup();
1028
1029         /* Open the /dev/console on the rootfs, this should never fail */
1030         if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
1031                 pr_err("Warning: unable to open an initial console.\n");
1032
1033         (void) sys_dup(0);
1034         (void) sys_dup(0);
1035         /*
1036          * check if there is an early userspace init.  If yes, let it do all
1037          * the work
1038          */
1039
1040         if (!ramdisk_execute_command)
1041                 ramdisk_execute_command = "/init";
1042
1043         if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
1044                 ramdisk_execute_command = NULL;
1045                 prepare_namespace();
1046         }
1047
1048         /*
1049          * Ok, we have completed the initial bootup, and
1050          * we're essentially up and running. Get rid of the
1051          * initmem segments and start the user-mode stuff..
1052          *
1053          * rootfs is available now, try loading the public keys
1054          * and default modules
1055          */
1056
1057         integrity_load_keys();
1058         load_default_modules();
1059 }