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 #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 bool __init obsolete_checksetup(char *line)
 168 {
 169         const struct obs_kernel_param *p;
 170         bool had_early_param = false;
 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 = true;
 183                         } else if (!p->setup_func) {
 184                                 pr_warn("Parameter %s is obsolete, ignored\n",
 185                                         p->str);
 186                                 return true;
 187                         } else if (p->setup_func(line + n))
 188                                 return true;
 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,
 239                                     const char *unused, void *arg)
 240 {
 241         if (val) {
 242                 /* param=val or param="val"? */
 243                 if (val == param+strlen(param)+1)
 244                         val[-1] = '=';
 245                 else if (val == param+strlen(param)+2) {
 246                         val[-2] = '=';
 247                         memmove(val-1, val, strlen(val)+1);
 248                         val--;
 249                 } else
 250                         BUG();
 251         }
 252         return 0;
 253 }
 254
 255 /* Anything after -- gets handed straight to init. */
 256 static int __init set_init_arg(char *param, char *val,
 257                                const char *unused, void *arg)
 258 {
 259         unsigned int i;
 260
 261         if (panic_later)
 262                 return 0;
 263
 264         repair_env_string(param, val, unused, NULL);
 265
 266         for (i = 0; argv_init[i]; i++) {
 267                 if (i == MAX_INIT_ARGS) {
 268                         panic_later = "init";
 269                         panic_param = param;
 270                         return 0;
 271                 }
 272         }
 273         argv_init[i] = param;
 274         return 0;
 275 }
 276
 277 /*
 278  * Unknown boot options get handed to init, unless they look like
 279  * unused parameters (modprobe will find them in /proc/cmdline).
 280  */
 281 static int __init unknown_bootoption(char *param, char *val,
 282                                      const char *unused, void *arg)
 283 {
 284         repair_env_string(param, val, unused, NULL);
 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 static inline void setup_nr_cpu_ids(void) { }
 355 static inline void smp_prepare_cpus(unsigned int maxcpus) { }
 356 #endif
 357
 358 /*
 359  * We need to store the untouched command line for future reference.
 360  * We also need to store the touched command line since the parameter
 361  * parsing is performed in place, and we should allow a component to
 362  * store reference of name/value for future reference.
 363  */
 364 static void __init setup_command_line(char *command_line)
 365 {
 366         saved_command_line =
 367                 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
 368         initcall_command_line =
 369                 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
 370         static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0);
 371         strcpy(saved_command_line, boot_command_line);
 372         strcpy(static_command_line, command_line);
 373 }
 374
 375 /*
 376  * We need to finalize in a non-__init function or else race conditions
 377  * between the root thread and the init thread may cause start_kernel to
 378  * be reaped by free_initmem before the root thread has proceeded to
 379  * cpu_idle.
 380  *
 381  * gcc-3.4 accidentally inlines this function, so use noinline.
 382  */
 383
 384 static __initdata DECLARE_COMPLETION(kthreadd_done);
 385
 386 static noinline void __init_refok rest_init(void)
 387 {
 388         int pid;
 389
 390         rcu_scheduler_starting();
 391         smpboot_thread_init();
 392         /*
 393          * We need to spawn init first so that it obtains pid 1, however
 394          * the init task will end up wanting to create kthreads, which, if
 395          * we schedule it before we create kthreadd, will OOPS.
 396          */
 397         kernel_thread(kernel_init, NULL, CLONE_FS);
 398         numa_default_policy();
 399         pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
 400         rcu_read_lock();
 401         kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
 402         rcu_read_unlock();
 403         complete(&kthreadd_done);
 404
 405         /*
 406          * The boot idle thread must execute schedule()
 407          * at least once to get things moving:
 408          */
 409         init_idle_bootup_task(current);
 410         schedule_preempt_disabled();
 411         /* Call into cpu_idle with preempt disabled */
 412         cpu_startup_entry(CPUHP_ONLINE);
 413 }
 414
 415 /* Check for early params. */
 416 static int __init do_early_param(char *param, char *val,
 417                                  const char *unused, void *arg)
 418 {
 419         const struct obs_kernel_param *p;
 420
 421         for (p = __setup_start; p < __setup_end; p++) {
 422                 if ((p->early && parameq(param, p->str)) ||
 423                     (strcmp(param, "console") == 0 &&
 424                      strcmp(p->str, "earlycon") == 0)
 425                 ) {
 426                         if (p->setup_func(val) != 0)
 427                                 pr_warn("Malformed early option '%s'\n", param);
 428                 }
 429         }
 430         /* We accept everything at this stage. */
 431         return 0;
 432 }
 433
 434 void __init parse_early_options(char *cmdline)
 435 {
 436         parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
 437                    do_early_param);
 438 }
 439
 440 /* Arch code calls this early on, or if not, just before other parsing. */
 441 void __init parse_early_param(void)
 442 {
 443         static int done __initdata;
 444         static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
 445
 446         if (done)
 447                 return;
 448
 449         /* All fall through to do_early_param. */
 450         strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 451         parse_early_options(tmp_cmdline);
 452         done = 1;
 453 }
 454
 455 /*
 456  *      Activate the first processor.
 457  */
 458
 459 static void __init boot_cpu_init(void)
 460 {
 461         int cpu = smp_processor_id();
 462         /* Mark the boot cpu "present", "online" etc for SMP and UP case */
 463         set_cpu_online(cpu, true);
 464         set_cpu_active(cpu, true);
 465         set_cpu_present(cpu, true);
 466         set_cpu_possible(cpu, true);
 467 }
 468
 469 void __init __weak smp_setup_processor_id(void)
 470 {
 471 }
 472
 473 # if THREAD_SIZE >= PAGE_SIZE
 474 void __init __weak thread_info_cache_init(void)
 475 {
 476 }
 477 #endif
 478
 479 /*
 480  * Set up kernel memory allocators
 481  */
 482 static void __init mm_init(void)
 483 {
 484         /*
 485          * page_ext requires contiguous pages,
 486          * bigger than MAX_ORDER unless SPARSEMEM.
 487          */
 488         page_ext_init_flatmem();
 489         mem_init();
 490         kmem_cache_init();
 491         percpu_init_late();
 492         pgtable_init();
 493         vmalloc_init();
 494         ioremap_huge_init();
 495 }
 496
 497 asmlinkage __visible void __init start_kernel(void)
 498 {
 499         char *command_line;
 500         char *after_dashes;
 501
 502         /*
 503          * Need to run as early as possible, to initialize the
 504          * lockdep hash:
 505          */
 506         lockdep_init();
 507         set_task_stack_end_magic(&init_task);
 508         smp_setup_processor_id();
 509         debug_objects_early_init();
 510
 511         /*
 512          * Set up the the initial canary ASAP:
 513          */
 514         boot_init_stack_canary();
 515
 516         cgroup_init_early();
 517
 518         local_irq_disable();
 519         early_boot_irqs_disabled = true;
 520
 521 /*
 522  * Interrupts are still disabled. Do necessary setups, then
 523  * enable them
 524  */
 525         boot_cpu_init();
 526         page_address_init();
 527         pr_notice("%s", linux_banner);
 528         setup_arch(&command_line);
 529         mm_init_cpumask(&init_mm);
 530         setup_command_line(command_line);
 531         setup_nr_cpu_ids();
 532         setup_per_cpu_areas();
 533         smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
 534
 535         build_all_zonelists(NULL, NULL);
 536         page_alloc_init();
 537
 538         pr_notice("Kernel command line: %s\n", boot_command_line);
 539         parse_early_param();
 540         after_dashes = parse_args("Booting kernel",
 541                                   static_command_line, __start___param,
 542                                   __stop___param - __start___param,
 543                                   -1, -1, NULL, &unknown_bootoption);
 544         if (!IS_ERR_OR_NULL(after_dashes))
 545                 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
 546                            NULL, set_init_arg);
 547
 548         jump_label_init();
 549
 550         /*
 551          * These use large bootmem allocations and must precede
 552          * kmem_cache_init()
 553          */
 554         setup_log_buf(0);
 555         pidhash_init();
 556         vfs_caches_init_early();
 557         sort_main_extable();
 558         trap_init();
 559         mm_init();
 560
 561         /*
 562          * Set up the scheduler prior starting any interrupts (such as the
 563          * timer interrupt). Full topology setup happens at smp_init()
 564          * time - but meanwhile we still have a functioning scheduler.
 565          */
 566         sched_init();
 567         /*
 568          * Disable preemption - early bootup scheduling is extremely
 569          * fragile until we cpu_idle() for the first time.
 570          */
 571         preempt_disable();
 572         if (WARN(!irqs_disabled(),
 573                  "Interrupts were enabled *very* early, fixing it\n"))
 574                 local_irq_disable();
 575         idr_init_cache();
 576         rcu_init();
 577
 578         /* trace_printk() and trace points may be used after this */
 579         trace_init();
 580
 581         context_tracking_init();
 582         radix_tree_init();
 583         /* init some links before init_ISA_irqs() */
 584         early_irq_init();
 585         init_IRQ();
 586         tick_init();
 587         rcu_init_nohz();
 588         init_timers();
 589         hrtimers_init();
 590         softirq_init();
 591         timekeeping_init();
 592         time_init();
 593         sched_clock_postinit();
 594         perf_event_init();
 595         profile_init();
 596         call_function_init();
 597         WARN(!irqs_disabled(), "Interrupts were enabled early\n");
 598         early_boot_irqs_disabled = false;
 599         local_irq_enable();
 600
 601         kmem_cache_init_late();
 602
 603         /*
 604          * HACK ALERT! This is early. We're enabling the console before
 605          * we've done PCI setups etc, and console_init() must be aware of
 606          * this. But we do want output early, in case something goes wrong.
 607          */
 608         console_init();
 609         if (panic_later)
 610                 panic("Too many boot %s vars at `%s'", panic_later,
 611                       panic_param);
 612
 613         lockdep_info();
 614
 615         /*
 616          * Need to run this when irqs are enabled, because it wants
 617          * to self-test [hard/soft]-irqs on/off lock inversion bugs
 618          * too:
 619          */
 620         locking_selftest();
 621
 622 #ifdef CONFIG_BLK_DEV_INITRD
 623         if (initrd_start && !initrd_below_start_ok &&
 624             page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
 625                 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
 626                     page_to_pfn(virt_to_page((void *)initrd_start)),
 627                     min_low_pfn);
 628                 initrd_start = 0;
 629         }
 630 #endif
 631         page_ext_init();
 632         debug_objects_mem_init();
 633         kmemleak_init();
 634         setup_per_cpu_pageset();
 635         numa_policy_init();
 636         if (late_time_init)
 637                 late_time_init();
 638         sched_clock_init();
 639         calibrate_delay();
 640         pidmap_init();
 641         anon_vma_init();
 642         acpi_early_init();
 643 #ifdef CONFIG_X86
 644         if (efi_enabled(EFI_RUNTIME_SERVICES))
 645                 efi_enter_virtual_mode();
 646 #endif
 647 #ifdef CONFIG_X86_ESPFIX64
 648         /* Should be run before the first non-init thread is created */
 649         init_espfix_bsp();
 650 #endif
 651         thread_info_cache_init();
 652         cred_init();
 653         fork_init();
 654         proc_caches_init();
 655         buffer_init();
 656         key_init();
 657         security_init();
 658         dbg_late_init();
 659         vfs_caches_init();
 660         signals_init();
 661         /* rootfs populating might need page-writeback */
 662         page_writeback_init();
 663         proc_root_init();
 664         nsfs_init();
 665         cpuset_init();
 666         cgroup_init();
 667         taskstats_init_early();
 668         delayacct_init();
 669
 670         check_bugs();
 671
 672         acpi_subsystem_init();
 673         sfi_init_late();
 674
 675         if (efi_enabled(EFI_RUNTIME_SERVICES)) {
 676                 efi_late_init();
 677                 efi_free_boot_services();
 678         }
 679
 680         ftrace_init();
 681
 682         /* Do the rest non-__init'ed, we're now alive */
 683         rest_init();
 684 }
 685
 686 /* Call all constructor functions linked into the kernel. */
 687 static void __init do_ctors(void)
 688 {
 689 #ifdef CONFIG_CONSTRUCTORS
 690         ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
 691
 692         for (; fn < (ctor_fn_t *) __ctors_end; fn++)
 693                 (*fn)();
 694 #endif
 695 }
 696
 697 bool initcall_debug;
 698 core_param(initcall_debug, initcall_debug, bool, 0644);
 699
 700 #ifdef CONFIG_KALLSYMS
 701 struct blacklist_entry {
 702         struct list_head next;
 703         char *buf;
 704 };
 705
 706 static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
 707
 708 static int __init initcall_blacklist(char *str)
 709 {
 710         char *str_entry;
 711         struct blacklist_entry *entry;
 712
 713         /* str argument is a comma-separated list of functions */
 714         do {
 715                 str_entry = strsep(&str, ",");
 716                 if (str_entry) {
 717                         pr_debug("blacklisting initcall %s\n", str_entry);
 718                         entry = alloc_bootmem(sizeof(*entry));
 719                         entry->buf = alloc_bootmem(strlen(str_entry) + 1);
 720                         strcpy(entry->buf, str_entry);
 721                         list_add(&entry->next, &blacklisted_initcalls);
 722                 }
 723         } while (str_entry);
 724
 725         return 0;
 726 }
 727
 728 static bool __init_or_module initcall_blacklisted(initcall_t fn)
 729 {
 730         struct list_head *tmp;
 731         struct blacklist_entry *entry;
 732         char *fn_name;
 733
 734         fn_name = kasprintf(GFP_KERNEL, "%pf", fn);
 735         if (!fn_name)
 736                 return false;
 737
 738         list_for_each(tmp, &blacklisted_initcalls) {
 739                 entry = list_entry(tmp, struct blacklist_entry, next);
 740                 if (!strcmp(fn_name, entry->buf)) {
 741                         pr_debug("initcall %s blacklisted\n", fn_name);
 742                         kfree(fn_name);
 743                         return true;
 744                 }
 745         }
 746
 747         kfree(fn_name);
 748         return false;
 749 }
 750 #else
 751 static int __init initcall_blacklist(char *str)
 752 {
 753         pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
 754         return 0;
 755 }
 756
 757 static bool __init_or_module initcall_blacklisted(initcall_t fn)
 758 {
 759         return false;
 760 }
 761 #endif
 762 __setup("initcall_blacklist=", initcall_blacklist);
 763
 764 static int __init_or_module do_one_initcall_debug(initcall_t fn)
 765 {
 766         ktime_t calltime, delta, rettime;
 767         unsigned long long duration;
 768         int ret;
 769
 770         printk(KERN_DEBUG "calling  %pF @ %i\n", fn, task_pid_nr(current));
 771         calltime = ktime_get();
 772         ret = fn();
 773         rettime = ktime_get();
 774         delta = ktime_sub(rettime, calltime);
 775         duration = (unsigned long long) ktime_to_ns(delta) >> 10;
 776         printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n",
 777                  fn, ret, duration);
 778
 779         return ret;
 780 }
 781
 782 int __init_or_module do_one_initcall(initcall_t fn)
 783 {
 784         int count = preempt_count();
 785         int ret;
 786         char msgbuf[64];
 787
 788         if (initcall_blacklisted(fn))
 789                 return -EPERM;
 790
 791         if (initcall_debug)
 792                 ret = do_one_initcall_debug(fn);
 793         else
 794                 ret = fn();
 795
 796         msgbuf[0] = 0;
 797
 798         if (preempt_count() != count) {
 799                 sprintf(msgbuf, "preemption imbalance ");
 800                 preempt_count_set(count);
 801         }
 802         if (irqs_disabled()) {
 803                 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
 804                 local_irq_enable();
 805         }
 806         WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
 807
 808         return ret;
 809 }
 810
 811
 812 extern initcall_t __initcall_start[];
 813 extern initcall_t __initcall0_start[];
 814 extern initcall_t __initcall1_start[];
 815 extern initcall_t __initcall2_start[];
 816 extern initcall_t __initcall3_start[];
 817 extern initcall_t __initcall4_start[];
 818 extern initcall_t __initcall5_start[];
 819 extern initcall_t __initcall6_start[];
 820 extern initcall_t __initcall7_start[];
 821 extern initcall_t __initcall_end[];
 822
 823 static initcall_t *initcall_levels[] __initdata = {
 824         __initcall0_start,
 825         __initcall1_start,
 826         __initcall2_start,
 827         __initcall3_start,
 828         __initcall4_start,
 829         __initcall5_start,
 830         __initcall6_start,
 831         __initcall7_start,
 832         __initcall_end,
 833 };
 834
 835 /* Keep these in sync with initcalls in include/linux/init.h */
 836 static char *initcall_level_names[] __initdata = {
 837         "early",
 838         "core",
 839         "postcore",
 840         "arch",
 841         "subsys",
 842         "fs",
 843         "device",
 844         "late",
 845 };
 846
 847 static void __init do_initcall_level(int level)
 848 {
 849         initcall_t *fn;
 850
 851         strcpy(initcall_command_line, saved_command_line);
 852         parse_args(initcall_level_names[level],
 853                    initcall_command_line, __start___param,
 854                    __stop___param - __start___param,
 855                    level, level,
 856                    NULL, &repair_env_string);
 857
 858         for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
 859                 do_one_initcall(*fn);
 860 }
 861
 862 static void __init do_initcalls(void)
 863 {
 864         int level;
 865
 866         for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
 867                 do_initcall_level(level);
 868 }
 869
 870 /*
 871  * Ok, the machine is now initialized. None of the devices
 872  * have been touched yet, but the CPU subsystem is up and
 873  * running, and memory and process management works.
 874  *
 875  * Now we can finally start doing some real work..
 876  */
 877 static void __init do_basic_setup(void)
 878 {
 879         cpuset_init_smp();
 880         shmem_init();
 881         driver_init();
 882         init_irq_proc();
 883         do_ctors();
 884         usermodehelper_enable();
 885         do_initcalls();
 886         random_int_secret_init();
 887 }
 888
 889 static void __init do_pre_smp_initcalls(void)
 890 {
 891         initcall_t *fn;
 892
 893         for (fn = __initcall_start; fn < __initcall0_start; fn++)
 894                 do_one_initcall(*fn);
 895 }
 896
 897 /*
 898  * This function requests modules which should be loaded by default and is
 899  * called twice right after initrd is mounted and right before init is
 900  * exec'd.  If such modules are on either initrd or rootfs, they will be
 901  * loaded before control is passed to userland.
 902  */
 903 void __init load_default_modules(void)
 904 {
 905         load_default_elevator_module();
 906 }
 907
 908 static int run_init_process(const char *init_filename)
 909 {
 910         argv_init[0] = init_filename;
 911         return do_execve(getname_kernel(init_filename),
 912                 (const char __user *const __user *)argv_init,
 913                 (const char __user *const __user *)envp_init);
 914 }
 915
 916 static int try_to_run_init_process(const char *init_filename)
 917 {
 918         int ret;
 919
 920         ret = run_init_process(init_filename);
 921
 922         if (ret && ret != -ENOENT) {
 923                 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
 924                        init_filename, ret);
 925         }
 926
 927         return ret;
 928 }
 929
 930 static noinline void __init kernel_init_freeable(void);
 931
 932 static int __ref kernel_init(void *unused)
 933 {
 934         int ret;
 935
 936         kernel_init_freeable();
 937         /* need to finish all async __init code before freeing the memory */
 938         async_synchronize_full();
 939         free_initmem();
 940         mark_rodata_ro();
 941         system_state = SYSTEM_RUNNING;
 942         numa_default_policy();
 943
 944         flush_delayed_fput();
 945
 946         rcu_end_inkernel_boot();
 947
 948         if (ramdisk_execute_command) {
 949                 ret = run_init_process(ramdisk_execute_command);
 950                 if (!ret)
 951                         return 0;
 952                 pr_err("Failed to execute %s (error %d)\n",
 953                        ramdisk_execute_command, ret);
 954         }
 955
 956         /*
 957          * We try each of these until one succeeds.
 958          *
 959          * The Bourne shell can be used instead of init if we are
 960          * trying to recover a really broken machine.
 961          */
 962         if (execute_command) {
 963                 ret = run_init_process(execute_command);
 964                 if (!ret)
 965                         return 0;
 966                 panic("Requested init %s failed (error %d).",
 967                       execute_command, ret);
 968         }
 969         if (!try_to_run_init_process("/sbin/init") ||
 970             !try_to_run_init_process("/etc/init") ||
 971             !try_to_run_init_process("/bin/init") ||
 972             !try_to_run_init_process("/bin/sh"))
 973                 return 0;
 974
 975         panic("No working init found.  Try passing init= option to kernel. "
 976               "See Linux Documentation/init.txt for guidance.");
 977 }
 978
 979 static noinline void __init kernel_init_freeable(void)
 980 {
 981         /*
 982          * Wait until kthreadd is all set-up.
 983          */
 984         wait_for_completion(&kthreadd_done);
 985
 986         /* Now the scheduler is fully set up and can do blocking allocations */
 987         gfp_allowed_mask = __GFP_BITS_MASK;
 988
 989         /*
 990          * init can allocate pages on any node
 991          */
 992         set_mems_allowed(node_states[N_MEMORY]);
 993         /*
 994          * init can run on any cpu.
 995          */
 996         set_cpus_allowed_ptr(current, cpu_all_mask);
 997
 998         cad_pid = task_pid(current);
 999
1000         smp_prepare_cpus(setup_max_cpus);
1001
1002         do_pre_smp_initcalls();
1003         lockup_detector_init();
1004
1005         smp_init();
1006         sched_init_smp();
1007
1008         page_alloc_init_late();
1009
1010         do_basic_setup();
1011
1012         /* Open the /dev/console on the rootfs, this should never fail */
1013         if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
1014                 pr_err("Warning: unable to open an initial console.\n");
1015
1016         (void) sys_dup(0);
1017         (void) sys_dup(0);
1018         /*
1019          * check if there is an early userspace init.  If yes, let it do all
1020          * the work
1021          */
1022
1023         if (!ramdisk_execute_command)
1024                 ramdisk_execute_command = "/init";
1025
1026         if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
1027                 ramdisk_execute_command = NULL;
1028                 prepare_namespace();
1029         }
1030
1031         /*
1032          * Ok, we have completed the initial bootup, and
1033          * we're essentially up and running. Get rid of the
1034          * initmem segments and start the user-mode stuff..
1035          *
1036          * rootfs is available now, try loading the public keys
1037          * and default modules
1038          */
1039
1040         integrity_load_keys();
1041         load_default_modules();
1042 }