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/stackprotector.h> 18 #include <linux/string.h> 19 #include <linux/ctype.h> 20 #include <linux/delay.h> 21 #include <linux/ioport.h> 22 #include <linux/init.h> 23 #include <linux/initrd.h> 24 #include <linux/bootmem.h> 25 #include <linux/acpi.h> 26 #include <linux/tty.h> 27 #include <linux/percpu.h> 28 #include <linux/kmod.h> 29 #include <linux/vmalloc.h> 30 #include <linux/kernel_stat.h> 31 #include <linux/start_kernel.h> 32 #include <linux/security.h> 33 #include <linux/smp.h> 34 #include <linux/profile.h> 35 #include <linux/rcupdate.h> 36 #include <linux/moduleparam.h> 37 #include <linux/kallsyms.h> 38 #include <linux/writeback.h> 39 #include <linux/cpu.h> 40 #include <linux/cpuset.h> 41 #include <linux/cgroup.h> 42 #include <linux/efi.h> 43 #include <linux/tick.h> 44 #include <linux/interrupt.h> 45 #include <linux/taskstats_kern.h> 46 #include <linux/delayacct.h> 47 #include <linux/unistd.h> 48 #include <linux/rmap.h> 49 #include <linux/mempolicy.h> 50 #include <linux/key.h> 51 #include <linux/buffer_head.h> 52 #include <linux/page_cgroup.h> 53 #include <linux/debug_locks.h> 54 #include <linux/debugobjects.h> 55 #include <linux/lockdep.h> 56 #include <linux/kmemleak.h> 57 #include <linux/pid_namespace.h> 58 #include <linux/device.h> 59 #include <linux/kthread.h> 60 #include <linux/sched.h> 61 #include <linux/signal.h> 62 #include <linux/idr.h> 63 #include <linux/kgdb.h> 64 #include <linux/ftrace.h> 65 #include <linux/async.h> 66 #include <linux/kmemcheck.h> 67 #include <linux/sfi.h> 68 #include <linux/shmem_fs.h> 69 #include <linux/slab.h> 70 #include <linux/perf_event.h> 71 72 #include <asm/io.h> 73 #include <asm/bugs.h> 74 #include <asm/setup.h> 75 #include <asm/sections.h> 76 #include <asm/cacheflush.h> 77 78 #ifdef CONFIG_X86_LOCAL_APIC 79 #include <asm/smp.h> 80 #endif 81 82 static int kernel_init(void *); 83 84 extern void init_IRQ(void); 85 extern void fork_init(unsigned long); 86 extern void mca_init(void); 87 extern void sbus_init(void); 88 extern void prio_tree_init(void); 89 extern void radix_tree_init(void); 90 #ifndef CONFIG_DEBUG_RODATA 91 static inline void mark_rodata_ro(void) { } 92 #endif 93 94 #ifdef CONFIG_TC 95 extern void tc_init(void); 96 #endif 97 98 /* 99 * Debug helper: via this flag we know that we are in 'early bootup code' 100 * where only the boot processor is running with IRQ disabled. This means 101 * two things - IRQ must not be enabled before the flag is cleared and some 102 * operations which are not allowed with IRQ disabled are allowed while the 103 * flag is set. 104 */ 105 bool early_boot_irqs_disabled __read_mostly; 106 107 enum system_states system_state __read_mostly; 108 EXPORT_SYMBOL(system_state); 109 110 /* 111 * Boot command-line arguments 112 */ 113 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT 114 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT 115 116 extern void time_init(void); 117 /* Default late time init is NULL. archs can override this later. */ 118 void (*__initdata late_time_init)(void); 119 extern void softirq_init(void); 120 121 /* Untouched command line saved by arch-specific code. */ 122 char __initdata boot_command_line[COMMAND_LINE_SIZE]; 123 /* Untouched saved command line (eg. for /proc) */ 124 char *saved_command_line; 125 /* Command line for parameter parsing */ 126 static char *static_command_line; 127 128 static char *execute_command; 129 static char *ramdisk_execute_command; 130 131 /* 132 * If set, this is an indication to the drivers that reset the underlying 133 * device before going ahead with the initialization otherwise driver might 134 * rely on the BIOS and skip the reset operation. 135 * 136 * This is useful if kernel is booting in an unreliable environment. 137 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been 138 * skipped and devices will be in unknown state. 139 */ 140 unsigned int reset_devices; 141 EXPORT_SYMBOL(reset_devices); 142 143 static int __init set_reset_devices(char *str) 144 { 145 reset_devices = 1; 146 return 1; 147 } 148 149 __setup("reset_devices", set_reset_devices); 150 151 static const char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; 152 const char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; 153 static const char *panic_later, *panic_param; 154 155 extern const struct obs_kernel_param __setup_start[], __setup_end[]; 156 157 static int __init obsolete_checksetup(char *line) 158 { 159 const struct obs_kernel_param *p; 160 int had_early_param = 0; 161 162 p = __setup_start; 163 do { 164 int n = strlen(p->str); 165 if (parameqn(line, p->str, n)) { 166 if (p->early) { 167 /* Already done in parse_early_param? 168 * (Needs exact match on param part). 169 * Keep iterating, as we can have early 170 * params and __setups of same names 8( */ 171 if (line[n] == '\0' || line[n] == '=') 172 had_early_param = 1; 173 } else if (!p->setup_func) { 174 printk(KERN_WARNING "Parameter %s is obsolete," 175 " ignored\n", p->str); 176 return 1; 177 } else if (p->setup_func(line + n)) 178 return 1; 179 } 180 p++; 181 } while (p < __setup_end); 182 183 return had_early_param; 184 } 185 186 /* 187 * This should be approx 2 Bo*oMips to start (note initial shift), and will 188 * still work even if initially too large, it will just take slightly longer 189 */ 190 unsigned long loops_per_jiffy = (1<<12); 191 192 EXPORT_SYMBOL(loops_per_jiffy); 193 194 static int __init debug_kernel(char *str) 195 { 196 console_loglevel = 10; 197 return 0; 198 } 199 200 static int __init quiet_kernel(char *str) 201 { 202 console_loglevel = 4; 203 return 0; 204 } 205 206 early_param("debug", debug_kernel); 207 early_param("quiet", quiet_kernel); 208 209 static int __init loglevel(char *str) 210 { 211 int newlevel; 212 213 /* 214 * Only update loglevel value when a correct setting was passed, 215 * to prevent blind crashes (when loglevel being set to 0) that 216 * are quite hard to debug 217 */ 218 if (get_option(&str, &newlevel)) { 219 console_loglevel = newlevel; 220 return 0; 221 } 222 223 return -EINVAL; 224 } 225 226 early_param("loglevel", loglevel); 227 228 /* Change NUL term back to "=", to make "param" the whole string. */ 229 static int __init repair_env_string(char *param, char *val, const char *unused) 230 { 231 if (val) { 232 /* param=val or param="val"? */ 233 if (val == param+strlen(param)+1) 234 val[-1] = '='; 235 else if (val == param+strlen(param)+2) { 236 val[-2] = '='; 237 memmove(val-1, val, strlen(val)+1); 238 val--; 239 } else 240 BUG(); 241 } 242 return 0; 243 } 244 245 /* 246 * Unknown boot options get handed to init, unless they look like 247 * unused parameters (modprobe will find them in /proc/cmdline). 248 */ 249 static int __init unknown_bootoption(char *param, char *val, const char *unused) 250 { 251 repair_env_string(param, val, unused); 252 253 /* Handle obsolete-style parameters */ 254 if (obsolete_checksetup(param)) 255 return 0; 256 257 /* Unused module parameter. */ 258 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) 259 return 0; 260 261 if (panic_later) 262 return 0; 263 264 if (val) { 265 /* Environment option */ 266 unsigned int i; 267 for (i = 0; envp_init[i]; i++) { 268 if (i == MAX_INIT_ENVS) { 269 panic_later = "Too many boot env vars at `%s'"; 270 panic_param = param; 271 } 272 if (!strncmp(param, envp_init[i], val - param)) 273 break; 274 } 275 envp_init[i] = param; 276 } else { 277 /* Command line option */ 278 unsigned int i; 279 for (i = 0; argv_init[i]; i++) { 280 if (i == MAX_INIT_ARGS) { 281 panic_later = "Too many boot init vars at `%s'"; 282 panic_param = param; 283 } 284 } 285 argv_init[i] = param; 286 } 287 return 0; 288 } 289 290 static int __init init_setup(char *str) 291 { 292 unsigned int i; 293 294 execute_command = str; 295 /* 296 * In case LILO is going to boot us with default command line, 297 * it prepends "auto" before the whole cmdline which makes 298 * the shell think it should execute a script with such name. 299 * So we ignore all arguments entered _before_ init=... [MJ] 300 */ 301 for (i = 1; i < MAX_INIT_ARGS; i++) 302 argv_init[i] = NULL; 303 return 1; 304 } 305 __setup("init=", init_setup); 306 307 static int __init rdinit_setup(char *str) 308 { 309 unsigned int i; 310 311 ramdisk_execute_command = str; 312 /* See "auto" comment in init_setup */ 313 for (i = 1; i < MAX_INIT_ARGS; i++) 314 argv_init[i] = NULL; 315 return 1; 316 } 317 __setup("rdinit=", rdinit_setup); 318 319 #ifndef CONFIG_SMP 320 static const unsigned int setup_max_cpus = NR_CPUS; 321 #ifdef CONFIG_X86_LOCAL_APIC 322 static void __init smp_init(void) 323 { 324 APIC_init_uniprocessor(); 325 } 326 #else 327 #define smp_init() do { } while (0) 328 #endif 329 330 static inline void setup_nr_cpu_ids(void) { } 331 static inline void smp_prepare_cpus(unsigned int maxcpus) { } 332 #endif 333 334 /* 335 * We need to store the untouched command line for future reference. 336 * We also need to store the touched command line since the parameter 337 * parsing is performed in place, and we should allow a component to 338 * store reference of name/value for future reference. 339 */ 340 static void __init setup_command_line(char *command_line) 341 { 342 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1); 343 static_command_line = alloc_bootmem(strlen (command_line)+1); 344 strcpy (saved_command_line, boot_command_line); 345 strcpy (static_command_line, command_line); 346 } 347 348 /* 349 * We need to finalize in a non-__init function or else race conditions 350 * between the root thread and the init thread may cause start_kernel to 351 * be reaped by free_initmem before the root thread has proceeded to 352 * cpu_idle. 353 * 354 * gcc-3.4 accidentally inlines this function, so use noinline. 355 */ 356 357 static __initdata DECLARE_COMPLETION(kthreadd_done); 358 359 static noinline void __init_refok rest_init(void) 360 { 361 int pid; 362 363 rcu_scheduler_starting(); 364 /* 365 * We need to spawn init first so that it obtains pid 1, however 366 * the init task will end up wanting to create kthreads, which, if 367 * we schedule it before we create kthreadd, will OOPS. 368 */ 369 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND); 370 numa_default_policy(); 371 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES); 372 rcu_read_lock(); 373 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); 374 rcu_read_unlock(); 375 complete(&kthreadd_done); 376 377 /* 378 * The boot idle thread must execute schedule() 379 * at least once to get things moving: 380 */ 381 init_idle_bootup_task(current); 382 schedule_preempt_disabled(); 383 /* Call into cpu_idle with preempt disabled */ 384 cpu_idle(); 385 } 386 387 /* Check for early params. */ 388 static int __init do_early_param(char *param, char *val, const char *unused) 389 { 390 const struct obs_kernel_param *p; 391 392 for (p = __setup_start; p < __setup_end; p++) { 393 if ((p->early && parameq(param, p->str)) || 394 (strcmp(param, "console") == 0 && 395 strcmp(p->str, "earlycon") == 0) 396 ) { 397 if (p->setup_func(val) != 0) 398 printk(KERN_WARNING 399 "Malformed early option '%s'\n", param); 400 } 401 } 402 /* We accept everything at this stage. */ 403 return 0; 404 } 405 406 void __init parse_early_options(char *cmdline) 407 { 408 parse_args("early options", cmdline, NULL, 0, 0, 0, do_early_param); 409 } 410 411 /* Arch code calls this early on, or if not, just before other parsing. */ 412 void __init parse_early_param(void) 413 { 414 static __initdata int done = 0; 415 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE]; 416 417 if (done) 418 return; 419 420 /* All fall through to do_early_param. */ 421 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); 422 parse_early_options(tmp_cmdline); 423 done = 1; 424 } 425 426 /* 427 * Activate the first processor. 428 */ 429 430 static void __init boot_cpu_init(void) 431 { 432 int cpu = smp_processor_id(); 433 /* Mark the boot cpu "present", "online" etc for SMP and UP case */ 434 set_cpu_online(cpu, true); 435 set_cpu_active(cpu, true); 436 set_cpu_present(cpu, true); 437 set_cpu_possible(cpu, true); 438 } 439 440 void __init __weak smp_setup_processor_id(void) 441 { 442 } 443 444 void __init __weak thread_info_cache_init(void) 445 { 446 } 447 448 /* 449 * Set up kernel memory allocators 450 */ 451 static void __init mm_init(void) 452 { 453 /* 454 * page_cgroup requires contiguous pages, 455 * bigger than MAX_ORDER unless SPARSEMEM. 456 */ 457 page_cgroup_init_flatmem(); 458 mem_init(); 459 kmem_cache_init(); 460 percpu_init_late(); 461 pgtable_cache_init(); 462 vmalloc_init(); 463 } 464 465 asmlinkage void __init start_kernel(void) 466 { 467 char * command_line; 468 extern const struct kernel_param __start___param[], __stop___param[]; 469 470 /* 471 * Need to run as early as possible, to initialize the 472 * lockdep hash: 473 */ 474 lockdep_init(); 475 smp_setup_processor_id(); 476 debug_objects_early_init(); 477 478 /* 479 * Set up the the initial canary ASAP: 480 */ 481 boot_init_stack_canary(); 482 483 cgroup_init_early(); 484 485 local_irq_disable(); 486 early_boot_irqs_disabled = true; 487 488 /* 489 * Interrupts are still disabled. Do necessary setups, then 490 * enable them 491 */ 492 tick_init(); 493 boot_cpu_init(); 494 page_address_init(); 495 printk(KERN_NOTICE "%s", linux_banner); 496 setup_arch(&command_line); 497 mm_init_owner(&init_mm, &init_task); 498 mm_init_cpumask(&init_mm); 499 setup_command_line(command_line); 500 setup_nr_cpu_ids(); 501 setup_per_cpu_areas(); 502 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ 503 504 build_all_zonelists(NULL); 505 page_alloc_init(); 506 507 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line); 508 parse_early_param(); 509 parse_args("Booting kernel", static_command_line, __start___param, 510 __stop___param - __start___param, 511 -1, -1, &unknown_bootoption); 512 513 jump_label_init(); 514 515 /* 516 * These use large bootmem allocations and must precede 517 * kmem_cache_init() 518 */ 519 setup_log_buf(0); 520 pidhash_init(); 521 vfs_caches_init_early(); 522 sort_main_extable(); 523 trap_init(); 524 mm_init(); 525 526 /* 527 * Set up the scheduler prior starting any interrupts (such as the 528 * timer interrupt). Full topology setup happens at smp_init() 529 * time - but meanwhile we still have a functioning scheduler. 530 */ 531 sched_init(); 532 /* 533 * Disable preemption - early bootup scheduling is extremely 534 * fragile until we cpu_idle() for the first time. 535 */ 536 preempt_disable(); 537 if (!irqs_disabled()) { 538 printk(KERN_WARNING "start_kernel(): bug: interrupts were " 539 "enabled *very* early, fixing it\n"); 540 local_irq_disable(); 541 } 542 idr_init_cache(); 543 perf_event_init(); 544 rcu_init(); 545 radix_tree_init(); 546 /* init some links before init_ISA_irqs() */ 547 early_irq_init(); 548 init_IRQ(); 549 prio_tree_init(); 550 init_timers(); 551 hrtimers_init(); 552 softirq_init(); 553 timekeeping_init(); 554 time_init(); 555 profile_init(); 556 call_function_init(); 557 if (!irqs_disabled()) 558 printk(KERN_CRIT "start_kernel(): bug: interrupts were " 559 "enabled early\n"); 560 early_boot_irqs_disabled = false; 561 local_irq_enable(); 562 563 kmem_cache_init_late(); 564 565 /* 566 * HACK ALERT! This is early. We're enabling the console before 567 * we've done PCI setups etc, and console_init() must be aware of 568 * this. But we do want output early, in case something goes wrong. 569 */ 570 console_init(); 571 if (panic_later) 572 panic(panic_later, panic_param); 573 574 lockdep_info(); 575 576 /* 577 * Need to run this when irqs are enabled, because it wants 578 * to self-test [hard/soft]-irqs on/off lock inversion bugs 579 * too: 580 */ 581 locking_selftest(); 582 583 #ifdef CONFIG_BLK_DEV_INITRD 584 if (initrd_start && !initrd_below_start_ok && 585 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { 586 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - " 587 "disabling it.\n", 588 page_to_pfn(virt_to_page((void *)initrd_start)), 589 min_low_pfn); 590 initrd_start = 0; 591 } 592 #endif 593 page_cgroup_init(); 594 debug_objects_mem_init(); 595 kmemleak_init(); 596 setup_per_cpu_pageset(); 597 numa_policy_init(); 598 if (late_time_init) 599 late_time_init(); 600 sched_clock_init(); 601 calibrate_delay(); 602 pidmap_init(); 603 anon_vma_init(); 604 #ifdef CONFIG_X86 605 if (efi_enabled) 606 efi_enter_virtual_mode(); 607 #endif 608 thread_info_cache_init(); 609 cred_init(); 610 fork_init(totalram_pages); 611 proc_caches_init(); 612 buffer_init(); 613 key_init(); 614 security_init(); 615 dbg_late_init(); 616 vfs_caches_init(totalram_pages); 617 signals_init(); 618 /* rootfs populating might need page-writeback */ 619 page_writeback_init(); 620 #ifdef CONFIG_PROC_FS 621 proc_root_init(); 622 #endif 623 cgroup_init(); 624 cpuset_init(); 625 taskstats_init_early(); 626 delayacct_init(); 627 628 check_bugs(); 629 630 acpi_early_init(); /* before LAPIC and SMP init */ 631 sfi_init_late(); 632 633 ftrace_init(); 634 635 /* Do the rest non-__init'ed, we're now alive */ 636 rest_init(); 637 } 638 639 /* Call all constructor functions linked into the kernel. */ 640 static void __init do_ctors(void) 641 { 642 #ifdef CONFIG_CONSTRUCTORS 643 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; 644 645 for (; fn < (ctor_fn_t *) __ctors_end; fn++) 646 (*fn)(); 647 #endif 648 } 649 650 bool initcall_debug; 651 core_param(initcall_debug, initcall_debug, bool, 0644); 652 653 static char msgbuf[64]; 654 655 static int __init_or_module do_one_initcall_debug(initcall_t fn) 656 { 657 ktime_t calltime, delta, rettime; 658 unsigned long long duration; 659 int ret; 660 661 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current)); 662 calltime = ktime_get(); 663 ret = fn(); 664 rettime = ktime_get(); 665 delta = ktime_sub(rettime, calltime); 666 duration = (unsigned long long) ktime_to_ns(delta) >> 10; 667 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n", fn, 668 ret, duration); 669 670 return ret; 671 } 672 673 int __init_or_module do_one_initcall(initcall_t fn) 674 { 675 int count = preempt_count(); 676 int ret; 677 678 if (initcall_debug) 679 ret = do_one_initcall_debug(fn); 680 else 681 ret = fn(); 682 683 msgbuf[0] = 0; 684 685 if (ret && ret != -ENODEV && initcall_debug) 686 sprintf(msgbuf, "error code %d ", ret); 687 688 if (preempt_count() != count) { 689 strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf)); 690 preempt_count() = count; 691 } 692 if (irqs_disabled()) { 693 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); 694 local_irq_enable(); 695 } 696 if (msgbuf[0]) { 697 printk("initcall %pF returned with %s\n", fn, msgbuf); 698 } 699 700 return ret; 701 } 702 703 704 extern initcall_t __initcall_start[]; 705 extern initcall_t __initcall0_start[]; 706 extern initcall_t __initcall1_start[]; 707 extern initcall_t __initcall2_start[]; 708 extern initcall_t __initcall3_start[]; 709 extern initcall_t __initcall4_start[]; 710 extern initcall_t __initcall5_start[]; 711 extern initcall_t __initcall6_start[]; 712 extern initcall_t __initcall7_start[]; 713 extern initcall_t __initcall_end[]; 714 715 static initcall_t *initcall_levels[] __initdata = { 716 __initcall0_start, 717 __initcall1_start, 718 __initcall2_start, 719 __initcall3_start, 720 __initcall4_start, 721 __initcall5_start, 722 __initcall6_start, 723 __initcall7_start, 724 __initcall_end, 725 }; 726 727 static char *initcall_level_names[] __initdata = { 728 "early", 729 "core", 730 "postcore", 731 "arch", 732 "subsys", 733 "fs", 734 "device", 735 "late", 736 }; 737 738 static void __init do_initcall_level(int level) 739 { 740 extern const struct kernel_param __start___param[], __stop___param[]; 741 initcall_t *fn; 742 743 strcpy(static_command_line, saved_command_line); 744 parse_args(initcall_level_names[level], 745 static_command_line, __start___param, 746 __stop___param - __start___param, 747 level, level, 748 &repair_env_string); 749 750 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) 751 do_one_initcall(*fn); 752 } 753 754 static void __init do_initcalls(void) 755 { 756 int level; 757 758 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) 759 do_initcall_level(level); 760 } 761 762 /* 763 * Ok, the machine is now initialized. None of the devices 764 * have been touched yet, but the CPU subsystem is up and 765 * running, and memory and process management works. 766 * 767 * Now we can finally start doing some real work.. 768 */ 769 static void __init do_basic_setup(void) 770 { 771 cpuset_init_smp(); 772 usermodehelper_init(); 773 shmem_init(); 774 driver_init(); 775 init_irq_proc(); 776 do_ctors(); 777 usermodehelper_enable(); 778 do_initcalls(); 779 } 780 781 static void __init do_pre_smp_initcalls(void) 782 { 783 initcall_t *fn; 784 785 for (fn = __initcall_start; fn < __initcall0_start; fn++) 786 do_one_initcall(*fn); 787 } 788 789 static void run_init_process(const char *init_filename) 790 { 791 argv_init[0] = init_filename; 792 kernel_execve(init_filename, argv_init, envp_init); 793 } 794 795 /* This is a non __init function. Force it to be noinline otherwise gcc 796 * makes it inline to init() and it becomes part of init.text section 797 */ 798 static noinline int init_post(void) 799 { 800 /* need to finish all async __init code before freeing the memory */ 801 async_synchronize_full(); 802 free_initmem(); 803 mark_rodata_ro(); 804 system_state = SYSTEM_RUNNING; 805 numa_default_policy(); 806 807 808 current->signal->flags |= SIGNAL_UNKILLABLE; 809 810 if (ramdisk_execute_command) { 811 run_init_process(ramdisk_execute_command); 812 printk(KERN_WARNING "Failed to execute %s\n", 813 ramdisk_execute_command); 814 } 815 816 /* 817 * We try each of these until one succeeds. 818 * 819 * The Bourne shell can be used instead of init if we are 820 * trying to recover a really broken machine. 821 */ 822 if (execute_command) { 823 run_init_process(execute_command); 824 printk(KERN_WARNING "Failed to execute %s. Attempting " 825 "defaults...\n", execute_command); 826 } 827 run_init_process("/sbin/init"); 828 run_init_process("/etc/init"); 829 run_init_process("/bin/init"); 830 run_init_process("/bin/sh"); 831 832 panic("No init found. Try passing init= option to kernel. " 833 "See Linux Documentation/init.txt for guidance."); 834 } 835 836 static int __init kernel_init(void * unused) 837 { 838 /* 839 * Wait until kthreadd is all set-up. 840 */ 841 wait_for_completion(&kthreadd_done); 842 843 /* Now the scheduler is fully set up and can do blocking allocations */ 844 gfp_allowed_mask = __GFP_BITS_MASK; 845 846 /* 847 * init can allocate pages on any node 848 */ 849 set_mems_allowed(node_states[N_HIGH_MEMORY]); 850 /* 851 * init can run on any cpu. 852 */ 853 set_cpus_allowed_ptr(current, cpu_all_mask); 854 855 cad_pid = task_pid(current); 856 857 smp_prepare_cpus(setup_max_cpus); 858 859 do_pre_smp_initcalls(); 860 lockup_detector_init(); 861 862 smp_init(); 863 sched_init_smp(); 864 865 do_basic_setup(); 866 867 /* Open the /dev/console on the rootfs, this should never fail */ 868 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0) 869 printk(KERN_WARNING "Warning: unable to open an initial console.\n"); 870 871 (void) sys_dup(0); 872 (void) sys_dup(0); 873 /* 874 * check if there is an early userspace init. If yes, let it do all 875 * the work 876 */ 877 878 if (!ramdisk_execute_command) 879 ramdisk_execute_command = "/init"; 880 881 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) { 882 ramdisk_execute_command = NULL; 883 prepare_namespace(); 884 } 885 886 /* 887 * Ok, we have completed the initial bootup, and 888 * we're essentially up and running. Get rid of the 889 * initmem segments and start the user-mode stuff.. 890 */ 891 892 init_post(); 893 return 0; 894 } 895