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/hdreg.h>
  26 #include <linux/bootmem.h>
  27 #include <linux/tty.h>
  28 #include <linux/gfp.h>
  29 #include <linux/percpu.h>
  30 #include <linux/kmod.h>
  31 #include <linux/kernel_stat.h>
  32 #include <linux/start_kernel.h>
  33 #include <linux/security.h>
  34 #include <linux/workqueue.h>
  35 #include <linux/profile.h>
  36 #include <linux/rcupdate.h>
  37 #include <linux/moduleparam.h>
  38 #include <linux/kallsyms.h>
  39 #include <linux/writeback.h>
  40 #include <linux/cpu.h>
  41 #include <linux/cpuset.h>
  42 #include <linux/cgroup.h>
  43 #include <linux/efi.h>
  44 #include <linux/tick.h>
  45 #include <linux/interrupt.h>
  46 #include <linux/taskstats_kern.h>
  47 #include <linux/delayacct.h>
  48 #include <linux/unistd.h>
  49 #include <linux/rmap.h>
  50 #include <linux/mempolicy.h>
  51 #include <linux/key.h>
  52 #include <linux/unwind.h>
  53 #include <linux/buffer_head.h>
  54 #include <linux/debug_locks.h>
  55 #include <linux/lockdep.h>
  56 #include <linux/pid_namespace.h>
  57 #include <linux/device.h>
  58 #include <linux/kthread.h>
  59 #include <linux/sched.h>
  60 #include <linux/signal.h>
  61
  62 #include <asm/io.h>
  63 #include <asm/bugs.h>
  64 #include <asm/setup.h>
  65 #include <asm/sections.h>
  66 #include <asm/cacheflush.h>
  67
  68 #ifdef CONFIG_X86_LOCAL_APIC
  69 #include <asm/smp.h>
  70 #endif
  71
  72 /*
  73  * This is one of the first .c files built. Error out early if we have compiler
  74  * trouble.
  75  */
  76
  77 #if __GNUC__ == 4 && __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ == 0
  78 #warning gcc-4.1.0 is known to miscompile the kernel.  A different compiler version is recommended.
  79 #endif
  80
  81 static int kernel_init(void *);
  82
  83 extern void init_IRQ(void);
  84 extern void fork_init(unsigned long);
  85 extern void mca_init(void);
  86 extern void sbus_init(void);
  87 extern void pidhash_init(void);
  88 extern void pidmap_init(void);
  89 extern void prio_tree_init(void);
  90 extern void radix_tree_init(void);
  91 extern void free_initmem(void);
  92 #ifdef  CONFIG_ACPI
  93 extern void acpi_early_init(void);
  94 #else
  95 static inline void acpi_early_init(void) { }
  96 #endif
  97 #ifndef CONFIG_DEBUG_RODATA
  98 static inline void mark_rodata_ro(void) { }
  99 #endif
 100
 101 #ifdef CONFIG_TC
 102 extern void tc_init(void);
 103 #endif
 104
 105 <<<<<<< HEAD:init/main.c
 106 #ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
 107 extern int populate_rootfs(void);
 108 #else
 109 static inline void populate_rootfs(void) {}
 110 #endif
 111
 112 =======
 113 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:init/main.c
 114 enum system_states system_state;
 115 EXPORT_SYMBOL(system_state);
 116
 117 /*
 118  * Boot command-line arguments
 119  */
 120 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
 121 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
 122
 123 extern void time_init(void);
 124 /* Default late time init is NULL. archs can override this later. */
 125 void (*late_time_init)(void);
 126 extern void softirq_init(void);
 127
 128 /* Untouched command line saved by arch-specific code. */
 129 char __initdata boot_command_line[COMMAND_LINE_SIZE];
 130 /* Untouched saved command line (eg. for /proc) */
 131 char *saved_command_line;
 132 /* Command line for parameter parsing */
 133 static char *static_command_line;
 134
 135 static char *execute_command;
 136 static char *ramdisk_execute_command;
 137
 138 #ifdef CONFIG_SMP
 139 /* Setup configured maximum number of CPUs to activate */
 140 unsigned int __initdata setup_max_cpus = NR_CPUS;
 141
 142 /*
 143  * Setup routine for controlling SMP activation
 144  *
 145  * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
 146  * activation entirely (the MPS table probe still happens, though).
 147  *
 148  * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
 149  * greater than 0, limits the maximum number of CPUs activated in
 150  * SMP mode to <NUM>.
 151  */
 152 #ifndef CONFIG_X86_IO_APIC
 153 static inline void disable_ioapic_setup(void) {};
 154 #endif
 155
 156 static int __init nosmp(char *str)
 157 {
 158         setup_max_cpus = 0;
 159         disable_ioapic_setup();
 160         return 0;
 161 }
 162
 163 early_param("nosmp", nosmp);
 164
 165 static int __init maxcpus(char *str)
 166 {
 167         get_option(&str, &setup_max_cpus);
 168         if (setup_max_cpus == 0)
 169                 disable_ioapic_setup();
 170
 171         return 0;
 172 }
 173
 174 early_param("maxcpus", maxcpus);
 175 #else
 176 #define setup_max_cpus NR_CPUS
 177 #endif
 178
 179 /*
 180  * If set, this is an indication to the drivers that reset the underlying
 181  * device before going ahead with the initialization otherwise driver might
 182  * rely on the BIOS and skip the reset operation.
 183  *
 184  * This is useful if kernel is booting in an unreliable environment.
 185  * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
 186  * skipped and devices will be in unknown state.
 187  */
 188 unsigned int reset_devices;
 189 EXPORT_SYMBOL(reset_devices);
 190
 191 static int __init set_reset_devices(char *str)
 192 {
 193         reset_devices = 1;
 194         return 1;
 195 }
 196
 197 __setup("reset_devices", set_reset_devices);
 198
 199 static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 200 char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
 201 static const char *panic_later, *panic_param;
 202
 203 extern struct obs_kernel_param __setup_start[], __setup_end[];
 204
 205 static int __init obsolete_checksetup(char *line)
 206 {
 207         struct obs_kernel_param *p;
 208         int had_early_param = 0;
 209
 210         p = __setup_start;
 211         do {
 212                 int n = strlen(p->str);
 213                 if (!strncmp(line, p->str, n)) {
 214                         if (p->early) {
 215                                 /* Already done in parse_early_param?
 216                                  * (Needs exact match on param part).
 217                                  * Keep iterating, as we can have early
 218                                  * params and __setups of same names 8( */
 219                                 if (line[n] == '\0' || line[n] == '=')
 220                                         had_early_param = 1;
 221                         } else if (!p->setup_func) {
 222                                 printk(KERN_WARNING "Parameter %s is obsolete,"
 223                                        " ignored\n", p->str);
 224                                 return 1;
 225                         } else if (p->setup_func(line + n))
 226                                 return 1;
 227                 }
 228                 p++;
 229         } while (p < __setup_end);
 230
 231         return had_early_param;
 232 }
 233
 234 /*
 235  * This should be approx 2 Bo*oMips to start (note initial shift), and will
 236  * still work even if initially too large, it will just take slightly longer
 237  */
 238 unsigned long loops_per_jiffy = (1<<12);
 239
 240 EXPORT_SYMBOL(loops_per_jiffy);
 241
 242 static int __init debug_kernel(char *str)
 243 {
 244         console_loglevel = 10;
 245         return 0;
 246 }
 247
 248 static int __init quiet_kernel(char *str)
 249 {
 250         console_loglevel = 4;
 251         return 0;
 252 }
 253
 254 early_param("debug", debug_kernel);
 255 early_param("quiet", quiet_kernel);
 256
 257 static int __init loglevel(char *str)
 258 {
 259         get_option(&str, &console_loglevel);
 260 <<<<<<< HEAD:init/main.c
 261         return 1;
 262 =======
 263         return 0;
 264 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:init/main.c
 265 }
 266
 267 early_param("loglevel", loglevel);
 268
 269 /*
 270  * Unknown boot options get handed to init, unless they look like
 271  * failed parameters
 272  */
 273 static int __init unknown_bootoption(char *param, char *val)
 274 {
 275         /* Change NUL term back to "=", to make "param" the whole string. */
 276         if (val) {
 277                 /* param=val or param="val"? */
 278                 if (val == param+strlen(param)+1)
 279                         val[-1] = '=';
 280                 else if (val == param+strlen(param)+2) {
 281                         val[-2] = '=';
 282                         memmove(val-1, val, strlen(val)+1);
 283                         val--;
 284                 } else
 285                         BUG();
 286         }
 287
 288         /* Handle obsolete-style parameters */
 289         if (obsolete_checksetup(param))
 290                 return 0;
 291
 292         /*
 293          * Preemptive maintenance for "why didn't my misspelled command
 294          * line work?"
 295          */
 296         if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
 297                 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
 298                 return 0;
 299         }
 300
 301         if (panic_later)
 302                 return 0;
 303
 304         if (val) {
 305                 /* Environment option */
 306                 unsigned int i;
 307                 for (i = 0; envp_init[i]; i++) {
 308                         if (i == MAX_INIT_ENVS) {
 309                                 panic_later = "Too many boot env vars at `%s'";
 310                                 panic_param = param;
 311                         }
 312                         if (!strncmp(param, envp_init[i], val - param))
 313                                 break;
 314                 }
 315                 envp_init[i] = param;
 316         } else {
 317                 /* Command line option */
 318                 unsigned int i;
 319                 for (i = 0; argv_init[i]; i++) {
 320                         if (i == MAX_INIT_ARGS) {
 321                                 panic_later = "Too many boot init vars at `%s'";
 322                                 panic_param = param;
 323                         }
 324                 }
 325                 argv_init[i] = param;
 326         }
 327         return 0;
 328 }
 329
 330 #ifdef CONFIG_DEBUG_PAGEALLOC
 331 int __read_mostly debug_pagealloc_enabled = 0;
 332 #endif
 333
 334 static int __init init_setup(char *str)
 335 {
 336         unsigned int i;
 337
 338         execute_command = str;
 339         /*
 340          * In case LILO is going to boot us with default command line,
 341          * it prepends "auto" before the whole cmdline which makes
 342          * the shell think it should execute a script with such name.
 343          * So we ignore all arguments entered _before_ init=... [MJ]
 344          */
 345         for (i = 1; i < MAX_INIT_ARGS; i++)
 346                 argv_init[i] = NULL;
 347         return 1;
 348 }
 349 __setup("init=", init_setup);
 350
 351 static int __init rdinit_setup(char *str)
 352 {
 353         unsigned int i;
 354
 355         ramdisk_execute_command = str;
 356         /* See "auto" comment in init_setup */
 357         for (i = 1; i < MAX_INIT_ARGS; i++)
 358                 argv_init[i] = NULL;
 359         return 1;
 360 }
 361 __setup("rdinit=", rdinit_setup);
 362
 363 #ifndef CONFIG_SMP
 364
 365 #ifdef CONFIG_X86_LOCAL_APIC
 366 static void __init smp_init(void)
 367 {
 368         APIC_init_uniprocessor();
 369 }
 370 #else
 371 #define smp_init()      do { } while (0)
 372 #endif
 373
 374 static inline void setup_per_cpu_areas(void) { }
 375 static inline void smp_prepare_cpus(unsigned int maxcpus) { }
 376
 377 #else
 378
 379 #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
 380 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
 381
 382 EXPORT_SYMBOL(__per_cpu_offset);
 383
 384 static void __init setup_per_cpu_areas(void)
 385 {
 386         unsigned long size, i;
 387         char *ptr;
 388         unsigned long nr_possible_cpus = num_possible_cpus();
 389
 390         /* Copy section for each CPU (we discard the original) */
 391         size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
 392         ptr = alloc_bootmem_pages(size * nr_possible_cpus);
 393
 394         for_each_possible_cpu(i) {
 395                 __per_cpu_offset[i] = ptr - __per_cpu_start;
 396                 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
 397                 ptr += size;
 398         }
 399 }
 400 #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
 401
 402 /* Called by boot processor to activate the rest. */
 403 static void __init smp_init(void)
 404 {
 405         unsigned int cpu;
 406
 407         /* FIXME: This should be done in userspace --RR */
 408         for_each_present_cpu(cpu) {
 409                 if (num_online_cpus() >= setup_max_cpus)
 410                         break;
 411                 if (!cpu_online(cpu))
 412                         cpu_up(cpu);
 413         }
 414
 415         /* Any cleanup work */
 416         printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
 417         smp_cpus_done(setup_max_cpus);
 418 }
 419
 420 #endif
 421
 422 /*
 423  * We need to store the untouched command line for future reference.
 424  * We also need to store the touched command line since the parameter
 425  * parsing is performed in place, and we should allow a component to
 426  * store reference of name/value for future reference.
 427  */
 428 static void __init setup_command_line(char *command_line)
 429 {
 430         saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
 431         static_command_line = alloc_bootmem(strlen (command_line)+1);
 432         strcpy (saved_command_line, boot_command_line);
 433         strcpy (static_command_line, command_line);
 434 }
 435
 436 /*
 437  * We need to finalize in a non-__init function or else race conditions
 438  * between the root thread and the init thread may cause start_kernel to
 439  * be reaped by free_initmem before the root thread has proceeded to
 440  * cpu_idle.
 441  *
 442  * gcc-3.4 accidentally inlines this function, so use noinline.
 443  */
 444
 445 static void noinline __init_refok rest_init(void)
 446         __releases(kernel_lock)
 447 {
 448         int pid;
 449
 450         kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
 451         numa_default_policy();
 452         pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
 453         kthreadd_task = find_task_by_pid(pid);
 454         unlock_kernel();
 455
 456         /*
 457          * The boot idle thread must execute schedule()
 458          * at least once to get things moving:
 459          */
 460         init_idle_bootup_task(current);
 461         preempt_enable_no_resched();
 462         schedule();
 463         preempt_disable();
 464
 465         /* Call into cpu_idle with preempt disabled */
 466         cpu_idle();
 467 }
 468
 469 /* Check for early params. */
 470 static int __init do_early_param(char *param, char *val)
 471 {
 472         struct obs_kernel_param *p;
 473
 474         for (p = __setup_start; p < __setup_end; p++) {
 475                 if ((p->early && strcmp(param, p->str) == 0) ||
 476                     (strcmp(param, "console") == 0 &&
 477                      strcmp(p->str, "earlycon") == 0)
 478                 ) {
 479                         if (p->setup_func(val) != 0)
 480                                 printk(KERN_WARNING
 481                                        "Malformed early option '%s'\n", param);
 482                 }
 483         }
 484         /* We accept everything at this stage. */
 485         return 0;
 486 }
 487
 488 /* Arch code calls this early on, or if not, just before other parsing. */
 489 void __init parse_early_param(void)
 490 {
 491         static __initdata int done = 0;
 492         static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
 493
 494         if (done)
 495                 return;
 496
 497         /* All fall through to do_early_param. */
 498         strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 499         parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
 500         done = 1;
 501 }
 502
 503 /*
 504  *      Activate the first processor.
 505  */
 506
 507 static void __init boot_cpu_init(void)
 508 {
 509         int cpu = smp_processor_id();
 510         /* Mark the boot cpu "present", "online" etc for SMP and UP case */
 511         cpu_set(cpu, cpu_online_map);
 512         cpu_set(cpu, cpu_present_map);
 513         cpu_set(cpu, cpu_possible_map);
 514 }
 515
 516 void __init __attribute__((weak)) smp_setup_processor_id(void)
 517 {
 518 }
 519
 520 asmlinkage void __init start_kernel(void)
 521 {
 522         char * command_line;
 523         extern struct kernel_param __start___param[], __stop___param[];
 524
 525         smp_setup_processor_id();
 526
 527         /*
 528          * Need to run as early as possible, to initialize the
 529          * lockdep hash:
 530          */
 531         unwind_init();
 532         lockdep_init();
 533         cgroup_init_early();
 534
 535         local_irq_disable();
 536         early_boot_irqs_off();
 537         early_init_irq_lock_class();
 538
 539 /*
 540  * Interrupts are still disabled. Do necessary setups, then
 541  * enable them
 542  */
 543         lock_kernel();
 544         tick_init();
 545         boot_cpu_init();
 546         page_address_init();
 547         printk(KERN_NOTICE);
 548         printk(linux_banner);
 549         setup_arch(&command_line);
 550         setup_command_line(command_line);
 551         unwind_setup();
 552         setup_per_cpu_areas();
 553         smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
 554
 555         /*
 556          * Set up the scheduler prior starting any interrupts (such as the
 557          * timer interrupt). Full topology setup happens at smp_init()
 558          * time - but meanwhile we still have a functioning scheduler.
 559          */
 560         sched_init();
 561         /*
 562          * Disable preemption - early bootup scheduling is extremely
 563          * fragile until we cpu_idle() for the first time.
 564          */
 565         preempt_disable();
 566         build_all_zonelists();
 567         page_alloc_init();
 568         printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
 569         parse_early_param();
 570         parse_args("Booting kernel", static_command_line, __start___param,
 571                    __stop___param - __start___param,
 572                    &unknown_bootoption);
 573         if (!irqs_disabled()) {
 574                 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
 575                                 "enabled *very* early, fixing it\n");
 576                 local_irq_disable();
 577         }
 578         sort_main_extable();
 579         trap_init();
 580         rcu_init();
 581         init_IRQ();
 582         pidhash_init();
 583         init_timers();
 584         hrtimers_init();
 585         softirq_init();
 586         timekeeping_init();
 587         time_init();
 588         profile_init();
 589         if (!irqs_disabled())
 590                 printk("start_kernel(): bug: interrupts were enabled early\n");
 591         early_boot_irqs_on();
 592         local_irq_enable();
 593
 594         /*
 595          * HACK ALERT! This is early. We're enabling the console before
 596          * we've done PCI setups etc, and console_init() must be aware of
 597          * this. But we do want output early, in case something goes wrong.
 598          */
 599         console_init();
 600         if (panic_later)
 601                 panic(panic_later, panic_param);
 602
 603         lockdep_info();
 604
 605         /*
 606          * Need to run this when irqs are enabled, because it wants
 607          * to self-test [hard/soft]-irqs on/off lock inversion bugs
 608          * too:
 609          */
 610         locking_selftest();
 611
 612 #ifdef CONFIG_BLK_DEV_INITRD
 613         if (initrd_start && !initrd_below_start_ok &&
 614                         initrd_start < min_low_pfn << PAGE_SHIFT) {
 615                 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
 616                     "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT);
 617                 initrd_start = 0;
 618         }
 619 #endif
 620         vfs_caches_init_early();
 621         cpuset_init_early();
 622         mem_init();
 623         enable_debug_pagealloc();
 624         cpu_hotplug_init();
 625         kmem_cache_init();
 626         setup_per_cpu_pageset();
 627         numa_policy_init();
 628         if (late_time_init)
 629                 late_time_init();
 630         calibrate_delay();
 631         pidmap_init();
 632         pgtable_cache_init();
 633         prio_tree_init();
 634         anon_vma_init();
 635 #ifdef CONFIG_X86
 636         if (efi_enabled)
 637                 efi_enter_virtual_mode();
 638 #endif
 639         fork_init(num_physpages);
 640         proc_caches_init();
 641         buffer_init();
 642         unnamed_dev_init();
 643         key_init();
 644         security_init();
 645         vfs_caches_init(num_physpages);
 646         radix_tree_init();
 647         signals_init();
 648         /* rootfs populating might need page-writeback */
 649         page_writeback_init();
 650 #ifdef CONFIG_PROC_FS
 651         proc_root_init();
 652 #endif
 653         cgroup_init();
 654         cpuset_init();
 655         taskstats_init_early();
 656         delayacct_init();
 657
 658         check_bugs();
 659
 660 <<<<<<< HEAD:init/main.c
 661         populate_rootfs(); /* For DSDT override from initramfs */
 662 =======
 663 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:init/main.c
 664         acpi_early_init(); /* before LAPIC and SMP init */
 665
 666         /* Do the rest non-__init'ed, we're now alive */
 667         rest_init();
 668 }
 669
 670 static int __initdata initcall_debug;
 671
 672 static int __init initcall_debug_setup(char *str)
 673 {
 674         initcall_debug = 1;
 675         return 1;
 676 }
 677 __setup("initcall_debug", initcall_debug_setup);
 678
 679 extern initcall_t __initcall_start[], __initcall_end[];
 680
 681 static void __init do_initcalls(void)
 682 {
 683         initcall_t *call;
 684         int count = preempt_count();
 685
 686         for (call = __initcall_start; call < __initcall_end; call++) {
 687                 ktime_t t0, t1, delta;
 688                 char *msg = NULL;
 689                 char msgbuf[40];
 690                 int result;
 691
 692                 if (initcall_debug) {
 693                         printk("Calling initcall 0x%p", *call);
 694                         print_fn_descriptor_symbol(": %s()",
 695                                         (unsigned long) *call);
 696                         printk("\n");
 697                         t0 = ktime_get();
 698                 }
 699
 700                 result = (*call)();
 701
 702                 if (initcall_debug) {
 703                         t1 = ktime_get();
 704                         delta = ktime_sub(t1, t0);
 705
 706                         printk("initcall 0x%p", *call);
 707                         print_fn_descriptor_symbol(": %s()",
 708                                         (unsigned long) *call);
 709                         printk(" returned %d.\n", result);
 710
 711                         printk("initcall 0x%p ran for %Ld msecs: ",
 712                                 *call, (unsigned long long)delta.tv64 >> 20);
 713                         print_fn_descriptor_symbol("%s()\n",
 714                                 (unsigned long) *call);
 715                 }
 716
 717                 if (result && result != -ENODEV && initcall_debug) {
 718                         sprintf(msgbuf, "error code %d", result);
 719                         msg = msgbuf;
 720                 }
 721                 if (preempt_count() != count) {
 722                         msg = "preemption imbalance";
 723                         preempt_count() = count;
 724                 }
 725                 if (irqs_disabled()) {
 726                         msg = "disabled interrupts";
 727                         local_irq_enable();
 728                 }
 729                 if (msg) {
 730                         printk(KERN_WARNING "initcall at 0x%p", *call);
 731                         print_fn_descriptor_symbol(": %s()",
 732                                         (unsigned long) *call);
 733                         printk(": returned with %s\n", msg);
 734                 }
 735         }
 736
 737         /* Make sure there is no pending stuff from the initcall sequence */
 738         flush_scheduled_work();
 739 }
 740
 741 /*
 742  * Ok, the machine is now initialized. None of the devices
 743  * have been touched yet, but the CPU subsystem is up and
 744  * running, and memory and process management works.
 745  *
 746  * Now we can finally start doing some real work..
 747  */
 748 static void __init do_basic_setup(void)
 749 {
 750         /* drivers will send hotplug events */
 751         init_workqueues();
 752         usermodehelper_init();
 753         driver_init();
 754         init_irq_proc();
 755         do_initcalls();
 756 }
 757
 758 static int __initdata nosoftlockup;
 759
 760 static int __init nosoftlockup_setup(char *str)
 761 {
 762         nosoftlockup = 1;
 763         return 1;
 764 }
 765 __setup("nosoftlockup", nosoftlockup_setup);
 766
 767 static void __init do_pre_smp_initcalls(void)
 768 {
 769         extern int spawn_ksoftirqd(void);
 770
 771         migration_init();
 772         spawn_ksoftirqd();
 773         if (!nosoftlockup)
 774                 spawn_softlockup_task();
 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 int noinline 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         if (ramdisk_execute_command) {
 801                 run_init_process(ramdisk_execute_command);
 802                 printk(KERN_WARNING "Failed to execute %s\n",
 803                                 ramdisk_execute_command);
 804         }
 805
 806         /*
 807          * We try each of these until one succeeds.
 808          *
 809          * The Bourne shell can be used instead of init if we are
 810          * trying to recover a really broken machine.
 811          */
 812         if (execute_command) {
 813                 run_init_process(execute_command);
 814                 printk(KERN_WARNING "Failed to execute %s.  Attempting "
 815                                         "defaults...\n", execute_command);
 816         }
 817         run_init_process("/sbin/init");
 818         run_init_process("/etc/init");
 819         run_init_process("/bin/init");
 820         run_init_process("/bin/sh");
 821
 822         panic("No init found.  Try passing init= option to kernel.");
 823 }
 824
 825 static int __init kernel_init(void * unused)
 826 {
 827         lock_kernel();
 828         /*
 829          * init can run on any cpu.
 830          */
 831         set_cpus_allowed(current, CPU_MASK_ALL);
 832         /*
 833          * Tell the world that we're going to be the grim
 834          * reaper of innocent orphaned children.
 835          *
 836          * We don't want people to have to make incorrect
 837          * assumptions about where in the task array this
 838          * can be found.
 839          */
 840         init_pid_ns.child_reaper = current;
 841
 842         cad_pid = task_pid(current);
 843
 844         smp_prepare_cpus(setup_max_cpus);
 845
 846         do_pre_smp_initcalls();
 847
 848         smp_init();
 849         sched_init_smp();
 850
 851         cpuset_init_smp();
 852
 853         do_basic_setup();
 854
 855         /*
 856          * check if there is an early userspace init.  If yes, let it do all
 857          * the work
 858          */
 859
 860         if (!ramdisk_execute_command)
 861                 ramdisk_execute_command = "/init";
 862
 863         if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
 864                 ramdisk_execute_command = NULL;
 865                 prepare_namespace();
 866         }
 867
 868         /*
 869          * Ok, we have completed the initial bootup, and
 870          * we're essentially up and running. Get rid of the
 871          * initmem segments and start the user-mode stuff..
 872          */
 873         init_post();
 874         return 0;
 875 }