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 #include <linux/types.h>
  13 #include <linux/module.h>
  14 #include <linux/proc_fs.h>
  15 #include <linux/kernel.h>
  16 #include <linux/syscalls.h>
  17 #include <linux/string.h>
  18 #include <linux/ctype.h>
  19 #include <linux/delay.h>
  20 #include <linux/utsname.h>
  21 #include <linux/ioport.h>
  22 #include <linux/init.h>
  23 #include <linux/smp_lock.h>
  24 #include <linux/initrd.h>
  25 #include <linux/bootmem.h>
  26 #include <linux/tty.h>
  27 #include <linux/gfp.h>
  28 #include <linux/percpu.h>
  29 #include <linux/kmod.h>
  30 #include <linux/vmalloc.h>
  31 #include <linux/kernel_stat.h>
  32 #include <linux/start_kernel.h>
  33 #include <linux/security.h>
  34 #include <linux/smp.h>
  35 #include <linux/workqueue.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_cgroup.h>
  55 #include <linux/debug_locks.h>
  56 #include <linux/debugobjects.h>
  57 #include <linux/lockdep.h>
  58 #include <linux/pid_namespace.h>
  59 #include <linux/device.h>
  60 #include <linux/kthread.h>
  61 #include <linux/sched.h>
  62 #include <linux/signal.h>
  63 #include <linux/idr.h>
  64 #include <linux/ftrace.h>
  65 #include <trace/boot.h>
  66
  67 #include <asm/io.h>
  68 #include <asm/bugs.h>
  69 #include <asm/setup.h>
  70 #include <asm/sections.h>
  71 #include <asm/cacheflush.h>
  72
  73 #ifdef CONFIG_X86_LOCAL_APIC
  74 #include <asm/smp.h>
  75 #endif
  76
  77 static int kernel_init(void *);
  78
  79 extern void init_IRQ(void);
  80 extern void fork_init(unsigned long);
  81 extern void mca_init(void);
  82 extern void sbus_init(void);
  83 extern void prio_tree_init(void);
  84 extern void radix_tree_init(void);
  85 extern void free_initmem(void);
  86 #ifdef  CONFIG_ACPI
  87 extern void acpi_early_init(void);
  88 #else
  89 static inline void acpi_early_init(void) { }
  90 #endif
  91 #ifndef CONFIG_DEBUG_RODATA
  92 static inline void mark_rodata_ro(void) { }
  93 #endif
  94
  95 #ifdef CONFIG_TC
  96 extern void tc_init(void);
  97 #endif
  98
  99 enum system_states system_state;
 100 EXPORT_SYMBOL(system_state);
 101
 102 /*
 103  * Boot command-line arguments
 104  */
 105 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
 106 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
 107
 108 extern void time_init(void);
 109 /* Default late time init is NULL. archs can override this later. */
 110 void (*__initdata late_time_init)(void);
 111 extern void softirq_init(void);
 112
 113 /* Untouched command line saved by arch-specific code. */
 114 char __initdata boot_command_line[COMMAND_LINE_SIZE];
 115 /* Untouched saved command line (eg. for /proc) */
 116 char *saved_command_line;
 117 /* Command line for parameter parsing */
 118 static char *static_command_line;
 119
 120 static char *execute_command;
 121 static char *ramdisk_execute_command;
 122
 123 #ifdef CONFIG_SMP
 124 /* Setup configured maximum number of CPUs to activate */
 125 unsigned int __initdata setup_max_cpus = NR_CPUS;
 126
 127 /*
 128  * Setup routine for controlling SMP activation
 129  *
 130  * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
 131  * activation entirely (the MPS table probe still happens, though).
 132  *
 133  * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
 134  * greater than 0, limits the maximum number of CPUs activated in
 135  * SMP mode to <NUM>.
 136  */
 137 #ifndef CONFIG_X86_IO_APIC
 138 static inline void disable_ioapic_setup(void) {};
 139 #endif
 140
 141 static int __init nosmp(char *str)
 142 {
 143         setup_max_cpus = 0;
 144         disable_ioapic_setup();
 145         return 0;
 146 }
 147
 148 early_param("nosmp", nosmp);
 149
 150 static int __init maxcpus(char *str)
 151 {
 152         get_option(&str, &setup_max_cpus);
 153         if (setup_max_cpus == 0)
 154                 disable_ioapic_setup();
 155
 156         return 0;
 157 }
 158
 159 early_param("maxcpus", maxcpus);
 160 #else
 161 #define setup_max_cpus NR_CPUS
 162 #endif
 163
 164 /*
 165  * If set, this is an indication to the drivers that reset the underlying
 166  * device before going ahead with the initialization otherwise driver might
 167  * rely on the BIOS and skip the reset operation.
 168  *
 169  * This is useful if kernel is booting in an unreliable environment.
 170  * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
 171  * skipped and devices will be in unknown state.
 172  */
 173 unsigned int reset_devices;
 174 EXPORT_SYMBOL(reset_devices);
 175
 176 static int __init set_reset_devices(char *str)
 177 {
 178         reset_devices = 1;
 179         return 1;
 180 }
 181
 182 __setup("reset_devices", set_reset_devices);
 183
 184 static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 185 char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
 186 static const char *panic_later, *panic_param;
 187
 188 extern struct obs_kernel_param __setup_start[], __setup_end[];
 189
 190 static int __init obsolete_checksetup(char *line)
 191 {
 192         struct obs_kernel_param *p;
 193         int had_early_param = 0;
 194
 195         p = __setup_start;
 196         do {
 197                 int n = strlen(p->str);
 198                 if (!strncmp(line, p->str, n)) {
 199                         if (p->early) {
 200                                 /* Already done in parse_early_param?
 201                                  * (Needs exact match on param part).
 202                                  * Keep iterating, as we can have early
 203                                  * params and __setups of same names 8( */
 204                                 if (line[n] == '\0' || line[n] == '=')
 205                                         had_early_param = 1;
 206                         } else if (!p->setup_func) {
 207                                 printk(KERN_WARNING "Parameter %s is obsolete,"
 208                                        " ignored\n", p->str);
 209                                 return 1;
 210                         } else if (p->setup_func(line + n))
 211                                 return 1;
 212                 }
 213                 p++;
 214         } while (p < __setup_end);
 215
 216         return had_early_param;
 217 }
 218
 219 /*
 220  * This should be approx 2 Bo*oMips to start (note initial shift), and will
 221  * still work even if initially too large, it will just take slightly longer
 222  */
 223 unsigned long loops_per_jiffy = (1<<12);
 224
 225 EXPORT_SYMBOL(loops_per_jiffy);
 226
 227 static int __init debug_kernel(char *str)
 228 {
 229         console_loglevel = 10;
 230         return 0;
 231 }
 232
 233 static int __init quiet_kernel(char *str)
 234 {
 235         console_loglevel = 4;
 236         return 0;
 237 }
 238
 239 early_param("debug", debug_kernel);
 240 early_param("quiet", quiet_kernel);
 241
 242 static int __init loglevel(char *str)
 243 {
 244         get_option(&str, &console_loglevel);
 245         return 0;
 246 }
 247
 248 early_param("loglevel", loglevel);
 249
 250 /*
 251  * Unknown boot options get handed to init, unless they look like
 252  * failed parameters
 253  */
 254 static int __init unknown_bootoption(char *param, char *val)
 255 {
 256         /* Change NUL term back to "=", to make "param" the whole string. */
 257         if (val) {
 258                 /* param=val or param="val"? */
 259                 if (val == param+strlen(param)+1)
 260                         val[-1] = '=';
 261                 else if (val == param+strlen(param)+2) {
 262                         val[-2] = '=';
 263                         memmove(val-1, val, strlen(val)+1);
 264                         val--;
 265                 } else
 266                         BUG();
 267         }
 268
 269         /* Handle obsolete-style parameters */
 270         if (obsolete_checksetup(param))
 271                 return 0;
 272
 273         /*
 274          * Preemptive maintenance for "why didn't my misspelled command
 275          * line work?"
 276          */
 277         if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
 278                 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
 279                 return 0;
 280         }
 281
 282         if (panic_later)
 283                 return 0;
 284
 285         if (val) {
 286                 /* Environment option */
 287                 unsigned int i;
 288                 for (i = 0; envp_init[i]; i++) {
 289                         if (i == MAX_INIT_ENVS) {
 290                                 panic_later = "Too many boot env vars at `%s'";
 291                                 panic_param = param;
 292                         }
 293                         if (!strncmp(param, envp_init[i], val - param))
 294                                 break;
 295                 }
 296                 envp_init[i] = param;
 297         } else {
 298                 /* Command line option */
 299                 unsigned int i;
 300                 for (i = 0; argv_init[i]; i++) {
 301                         if (i == MAX_INIT_ARGS) {
 302                                 panic_later = "Too many boot init vars at `%s'";
 303                                 panic_param = param;
 304                         }
 305                 }
 306                 argv_init[i] = param;
 307         }
 308         return 0;
 309 }
 310
 311 #ifdef CONFIG_DEBUG_PAGEALLOC
 312 int __read_mostly debug_pagealloc_enabled = 0;
 313 #endif
 314
 315 static int __init init_setup(char *str)
 316 {
 317         unsigned int i;
 318
 319         execute_command = str;
 320         /*
 321          * In case LILO is going to boot us with default command line,
 322          * it prepends "auto" before the whole cmdline which makes
 323          * the shell think it should execute a script with such name.
 324          * So we ignore all arguments entered _before_ init=... [MJ]
 325          */
 326         for (i = 1; i < MAX_INIT_ARGS; i++)
 327                 argv_init[i] = NULL;
 328         return 1;
 329 }
 330 __setup("init=", init_setup);
 331
 332 static int __init rdinit_setup(char *str)
 333 {
 334         unsigned int i;
 335
 336         ramdisk_execute_command = str;
 337         /* See "auto" comment in init_setup */
 338         for (i = 1; i < MAX_INIT_ARGS; i++)
 339                 argv_init[i] = NULL;
 340         return 1;
 341 }
 342 __setup("rdinit=", rdinit_setup);
 343
 344 #ifndef CONFIG_SMP
 345
 346 #ifdef CONFIG_X86_LOCAL_APIC
 347 static void __init smp_init(void)
 348 {
 349         APIC_init_uniprocessor();
 350 }
 351 #else
 352 #define smp_init()      do { } while (0)
 353 #endif
 354
 355 static inline void setup_per_cpu_areas(void) { }
 356 static inline void setup_nr_cpu_ids(void) { }
 357 static inline void smp_prepare_cpus(unsigned int maxcpus) { }
 358
 359 #else
 360
 361 #if NR_CPUS > BITS_PER_LONG
 362 cpumask_t cpu_mask_all __read_mostly = CPU_MASK_ALL;
 363 EXPORT_SYMBOL(cpu_mask_all);
 364 #endif
 365
 366 /* Setup number of possible processor ids */
 367 int nr_cpu_ids __read_mostly = NR_CPUS;
 368 EXPORT_SYMBOL(nr_cpu_ids);
 369
 370 /* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
 371 static void __init setup_nr_cpu_ids(void)
 372 {
 373         nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1;
 374 }
 375
 376 #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
 377 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
 378
 379 EXPORT_SYMBOL(__per_cpu_offset);
 380
 381 static void __init setup_per_cpu_areas(void)
 382 {
 383         unsigned long size, i;
 384         char *ptr;
 385         unsigned long nr_possible_cpus = num_possible_cpus();
 386
 387         /* Copy section for each CPU (we discard the original) */
 388         size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
 389         ptr = alloc_bootmem_pages(size * nr_possible_cpus);
 390
 391         for_each_possible_cpu(i) {
 392                 __per_cpu_offset[i] = ptr - __per_cpu_start;
 393                 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
 394                 ptr += size;
 395         }
 396 }
 397 #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
 398
 399 /* Called by boot processor to activate the rest. */
 400 static void __init smp_init(void)
 401 {
 402         unsigned int cpu;
 403
 404         /*
 405          * Set up the current CPU as possible to migrate to.
 406          * The other ones will be done by cpu_up/cpu_down()
 407          */
 408         cpu = smp_processor_id();
 409         cpu_set(cpu, cpu_active_map);
 410
 411         /* FIXME: This should be done in userspace --RR */
 412         for_each_present_cpu(cpu) {
 413                 if (num_online_cpus() >= setup_max_cpus)
 414                         break;
 415                 if (!cpu_online(cpu))
 416                         cpu_up(cpu);
 417         }
 418
 419         /* Any cleanup work */
 420         printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
 421         smp_cpus_done(setup_max_cpus);
 422 }
 423
 424 #endif
 425
 426 /*
 427  * We need to store the untouched command line for future reference.
 428  * We also need to store the touched command line since the parameter
 429  * parsing is performed in place, and we should allow a component to
 430  * store reference of name/value for future reference.
 431  */
 432 static void __init setup_command_line(char *command_line)
 433 {
 434         saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
 435         static_command_line = alloc_bootmem(strlen (command_line)+1);
 436         strcpy (saved_command_line, boot_command_line);
 437         strcpy (static_command_line, command_line);
 438 }
 439
 440 /*
 441  * We need to finalize in a non-__init function or else race conditions
 442  * between the root thread and the init thread may cause start_kernel to
 443  * be reaped by free_initmem before the root thread has proceeded to
 444  * cpu_idle.
 445  *
 446  * gcc-3.4 accidentally inlines this function, so use noinline.
 447  */
 448
 449 static noinline void __init_refok rest_init(void)
 450         __releases(kernel_lock)
 451 {
 452         int pid;
 453
 454         kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
 455         numa_default_policy();
 456         pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
 457         kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
 458         unlock_kernel();
 459
 460         /*
 461          * The boot idle thread must execute schedule()
 462          * at least once to get things moving:
 463          */
 464         init_idle_bootup_task(current);
 465         preempt_enable_no_resched();
 466         schedule();
 467         preempt_disable();
 468
 469         /* Call into cpu_idle with preempt disabled */
 470         cpu_idle();
 471 }
 472
 473 /* Check for early params. */
 474 static int __init do_early_param(char *param, char *val)
 475 {
 476         struct obs_kernel_param *p;
 477
 478         for (p = __setup_start; p < __setup_end; p++) {
 479                 if ((p->early && strcmp(param, p->str) == 0) ||
 480                     (strcmp(param, "console") == 0 &&
 481                      strcmp(p->str, "earlycon") == 0)
 482                 ) {
 483                         if (p->setup_func(val) != 0)
 484                                 printk(KERN_WARNING
 485                                        "Malformed early option '%s'\n", param);
 486                 }
 487         }
 488         /* We accept everything at this stage. */
 489         return 0;
 490 }
 491
 492 /* Arch code calls this early on, or if not, just before other parsing. */
 493 void __init parse_early_param(void)
 494 {
 495         static __initdata int done = 0;
 496         static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
 497
 498         if (done)
 499                 return;
 500
 501         /* All fall through to do_early_param. */
 502         strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 503         parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
 504         done = 1;
 505 }
 506
 507 /*
 508  *      Activate the first processor.
 509  */
 510
 511 static void __init boot_cpu_init(void)
 512 {
 513         int cpu = smp_processor_id();
 514         /* Mark the boot cpu "present", "online" etc for SMP and UP case */
 515         set_cpu_online(cpu, true);
 516         set_cpu_present(cpu, true);
 517         set_cpu_possible(cpu, true);
 518 }
 519
 520 void __init __weak smp_setup_processor_id(void)
 521 {
 522 }
 523
 524 void __init __weak thread_info_cache_init(void)
 525 {
 526 }
 527
 528 asmlinkage void __init start_kernel(void)
 529 {
 530         char * command_line;
 531         extern struct kernel_param __start___param[], __stop___param[];
 532
 533         smp_setup_processor_id();
 534
 535         /*
 536          * Need to run as early as possible, to initialize the
 537          * lockdep hash:
 538          */
 539         lockdep_init();
 540         debug_objects_early_init();
 541         cgroup_init_early();
 542
 543         local_irq_disable();
 544         early_boot_irqs_off();
 545         early_init_irq_lock_class();
 546
 547 /*
 548  * Interrupts are still disabled. Do necessary setups, then
 549  * enable them
 550  */
 551         lock_kernel();
 552         tick_init();
 553         boot_cpu_init();
 554         page_address_init();
 555         printk(KERN_NOTICE);
 556         printk(linux_banner);
 557         setup_arch(&command_line);
 558         mm_init_owner(&init_mm, &init_task);
 559         setup_command_line(command_line);
 560         setup_per_cpu_areas();
 561         setup_nr_cpu_ids();
 562         smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
 563
 564         /*
 565          * Set up the scheduler prior starting any interrupts (such as the
 566          * timer interrupt). Full topology setup happens at smp_init()
 567          * time - but meanwhile we still have a functioning scheduler.
 568          */
 569         sched_init();
 570         /*
 571          * Disable preemption - early bootup scheduling is extremely
 572          * fragile until we cpu_idle() for the first time.
 573          */
 574         preempt_disable();
 575         build_all_zonelists();
 576         page_alloc_init();
 577         printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
 578         parse_early_param();
 579         parse_args("Booting kernel", static_command_line, __start___param,
 580                    __stop___param - __start___param,
 581                    &unknown_bootoption);
 582         if (!irqs_disabled()) {
 583                 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
 584                                 "enabled *very* early, fixing it\n");
 585                 local_irq_disable();
 586         }
 587         sort_main_extable();
 588         trap_init();
 589         rcu_init();
 590         /* init some links before init_ISA_irqs() */
 591         early_irq_init();
 592         init_IRQ();
 593         pidhash_init();
 594         init_timers();
 595         hrtimers_init();
 596         softirq_init();
 597         timekeeping_init();
 598         time_init();
 599         sched_clock_init();
 600         profile_init();
 601         if (!irqs_disabled())
 602                 printk("start_kernel(): bug: interrupts were enabled early\n");
 603         early_boot_irqs_on();
 604         local_irq_enable();
 605
 606         /*
 607          * HACK ALERT! This is early. We're enabling the console before
 608          * we've done PCI setups etc, and console_init() must be aware of
 609          * this. But we do want output early, in case something goes wrong.
 610          */
 611         console_init();
 612         if (panic_later)
 613                 panic(panic_later, panic_param);
 614
 615         lockdep_info();
 616
 617         /*
 618          * Need to run this when irqs are enabled, because it wants
 619          * to self-test [hard/soft]-irqs on/off lock inversion bugs
 620          * too:
 621          */
 622         locking_selftest();
 623
 624 #ifdef CONFIG_BLK_DEV_INITRD
 625         if (initrd_start && !initrd_below_start_ok &&
 626             page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
 627                 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
 628                     "disabling it.\n",
 629                     page_to_pfn(virt_to_page((void *)initrd_start)),
 630                     min_low_pfn);
 631                 initrd_start = 0;
 632         }
 633 #endif
 634         vmalloc_init();
 635         vfs_caches_init_early();
 636         cpuset_init_early();
 637         page_cgroup_init();
 638         mem_init();
 639         enable_debug_pagealloc();
 640         cpu_hotplug_init();
 641         kmem_cache_init();
 642         debug_objects_mem_init();
 643         idr_init_cache();
 644         setup_per_cpu_pageset();
 645         numa_policy_init();
 646         if (late_time_init)
 647                 late_time_init();
 648         calibrate_delay();
 649         pidmap_init();
 650         pgtable_cache_init();
 651         prio_tree_init();
 652         anon_vma_init();
 653 #ifdef CONFIG_X86
 654         if (efi_enabled)
 655                 efi_enter_virtual_mode();
 656 #endif
 657         thread_info_cache_init();
 658         cred_init();
 659         fork_init(num_physpages);
 660         proc_caches_init();
 661         buffer_init();
 662         key_init();
 663         security_init();
 664         vfs_caches_init(num_physpages);
 665         radix_tree_init();
 666         signals_init();
 667         /* rootfs populating might need page-writeback */
 668         page_writeback_init();
 669 #ifdef CONFIG_PROC_FS
 670         proc_root_init();
 671 #endif
 672         cgroup_init();
 673         cpuset_init();
 674         taskstats_init_early();
 675         delayacct_init();
 676
 677         check_bugs();
 678
 679         acpi_early_init(); /* before LAPIC and SMP init */
 680
 681         ftrace_init();
 682
 683         /* Do the rest non-__init'ed, we're now alive */
 684         rest_init();
 685 }
 686
 687 static int initcall_debug;
 688 core_param(initcall_debug, initcall_debug, bool, 0644);
 689
 690 int do_one_initcall(initcall_t fn)
 691 {
 692         int count = preempt_count();
 693         ktime_t calltime, delta, rettime;
 694         char msgbuf[64];
 695         struct boot_trace_call call;
 696         struct boot_trace_ret ret;
 697
 698         if (initcall_debug) {
 699                 call.caller = task_pid_nr(current);
 700                 printk("calling  %pF @ %i\n", fn, call.caller);
 701                 calltime = ktime_get();
 702                 trace_boot_call(&call, fn);
 703                 enable_boot_trace();
 704         }
 705
 706         ret.result = fn();
 707
 708         if (initcall_debug) {
 709                 disable_boot_trace();
 710                 rettime = ktime_get();
 711                 delta = ktime_sub(rettime, calltime);
 712                 ret.duration = (unsigned long long) ktime_to_ns(delta) >> 10;
 713                 trace_boot_ret(&ret, fn);
 714                 printk("initcall %pF returned %d after %Ld usecs\n", fn,
 715                         ret.result, ret.duration);
 716         }
 717
 718         msgbuf[0] = 0;
 719
 720         if (ret.result && ret.result != -ENODEV && initcall_debug)
 721                 sprintf(msgbuf, "error code %d ", ret.result);
 722
 723         if (preempt_count() != count) {
 724                 strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
 725                 preempt_count() = count;
 726         }
 727         if (irqs_disabled()) {
 728                 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
 729                 local_irq_enable();
 730         }
 731         if (msgbuf[0]) {
 732                 printk("initcall %pF returned with %s\n", fn, msgbuf);
 733         }
 734
 735         return ret.result;
 736 }
 737
 738
 739 extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[];
 740
 741 static void __init do_initcalls(void)
 742 {
 743         initcall_t *call;
 744
 745         for (call = __early_initcall_end; call < __initcall_end; call++)
 746                 do_one_initcall(*call);
 747
 748         /* Make sure there is no pending stuff from the initcall sequence */
 749         flush_scheduled_work();
 750 }
 751
 752 /*
 753  * Ok, the machine is now initialized. None of the devices
 754  * have been touched yet, but the CPU subsystem is up and
 755  * running, and memory and process management works.
 756  *
 757  * Now we can finally start doing some real work..
 758  */
 759 static void __init do_basic_setup(void)
 760 {
 761         rcu_init_sched(); /* needed by module_init stage. */
 762         init_workqueues();
 763         usermodehelper_init();
 764         driver_init();
 765         init_irq_proc();
 766         do_initcalls();
 767 }
 768
 769 static void __init do_pre_smp_initcalls(void)
 770 {
 771         initcall_t *call;
 772
 773         for (call = __initcall_start; call < __early_initcall_end; call++)
 774                 do_one_initcall(*call);
 775 }
 776
 777 static void run_init_process(char *init_filename)
 778 {
 779         argv_init[0] = init_filename;
 780         kernel_execve(init_filename, argv_init, envp_init);
 781 }
 782
 783 /* This is a non __init function. Force it to be noinline otherwise gcc
 784  * makes it inline to init() and it becomes part of init.text section
 785  */
 786 static noinline int init_post(void)
 787 {
 788         free_initmem();
 789         unlock_kernel();
 790         mark_rodata_ro();
 791         system_state = SYSTEM_RUNNING;
 792         numa_default_policy();
 793
 794         if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
 795                 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
 796
 797         (void) sys_dup(0);
 798         (void) sys_dup(0);
 799
 800         current->signal->flags |= SIGNAL_UNKILLABLE;
 801
 802         if (ramdisk_execute_command) {
 803                 run_init_process(ramdisk_execute_command);
 804                 printk(KERN_WARNING "Failed to execute %s\n",
 805                                 ramdisk_execute_command);
 806         }
 807
 808         /*
 809          * We try each of these until one succeeds.
 810          *
 811          * The Bourne shell can be used instead of init if we are
 812          * trying to recover a really broken machine.
 813          */
 814         if (execute_command) {
 815                 run_init_process(execute_command);
 816                 printk(KERN_WARNING "Failed to execute %s.  Attempting "
 817                                         "defaults...\n", execute_command);
 818         }
 819         run_init_process("/sbin/init");
 820         run_init_process("/etc/init");
 821         run_init_process("/bin/init");
 822         run_init_process("/bin/sh");
 823
 824         panic("No init found.  Try passing init= option to kernel.");
 825 }
 826
 827 static int __init kernel_init(void * unused)
 828 {
 829         lock_kernel();
 830         /*
 831          * init can run on any cpu.
 832          */
 833         set_cpus_allowed_ptr(current, CPU_MASK_ALL_PTR);
 834         /*
 835          * Tell the world that we're going to be the grim
 836          * reaper of innocent orphaned children.
 837          *
 838          * We don't want people to have to make incorrect
 839          * assumptions about where in the task array this
 840          * can be found.
 841          */
 842         init_pid_ns.child_reaper = current;
 843
 844         cad_pid = task_pid(current);
 845
 846         smp_prepare_cpus(setup_max_cpus);
 847
 848         do_pre_smp_initcalls();
 849         start_boot_trace();
 850
 851         smp_init();
 852         sched_init_smp();
 853
 854         cpuset_init_smp();
 855
 856         do_basic_setup();
 857
 858         /*
 859          * check if there is an early userspace init.  If yes, let it do all
 860          * the work
 861          */
 862
 863         if (!ramdisk_execute_command)
 864                 ramdisk_execute_command = "/init";
 865
 866         if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
 867                 ramdisk_execute_command = NULL;
 868                 prepare_namespace();
 869         }
 870
 871         /*
 872          * Ok, we have completed the initial bootup, and
 873          * we're essentially up and running. Get rid of the
 874          * initmem segments and start the user-mode stuff..
 875          */
 876
 877         init_post();
 878         return 0;
 879 }