Version:  2.0.40 2.2.26 2.4.37 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19

Linux/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 
 84 #include <asm/io.h>
 85 #include <asm/bugs.h>
 86 #include <asm/setup.h>
 87 #include <asm/sections.h>
 88 #include <asm/cacheflush.h>
 89 
 90 #ifdef CONFIG_X86_LOCAL_APIC
 91 #include <asm/smp.h>
 92 #endif
 93 
 94 static int kernel_init(void *);
 95 
 96 extern void init_IRQ(void);
 97 extern void fork_init(unsigned long);
 98 extern void radix_tree_init(void);
 99 #ifndef CONFIG_DEBUG_RODATA
100 static inline void mark_rodata_ro(void) { }
101 #endif
102 
103 /*
104  * Debug helper: via this flag we know that we are in 'early bootup code'
105  * where only the boot processor is running with IRQ disabled.  This means
106  * two things - IRQ must not be enabled before the flag is cleared and some
107  * operations which are not allowed with IRQ disabled are allowed while the
108  * flag is set.
109  */
110 bool early_boot_irqs_disabled __read_mostly;
111 
112 enum system_states system_state __read_mostly;
113 EXPORT_SYMBOL(system_state);
114 
115 /*
116  * Boot command-line arguments
117  */
118 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
119 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
120 
121 extern void time_init(void);
122 /* Default late time init is NULL. archs can override this later. */
123 void (*__initdata late_time_init)(void);
124 
125 /* Untouched command line saved by arch-specific code. */
126 char __initdata boot_command_line[COMMAND_LINE_SIZE];
127 /* Untouched saved command line (eg. for /proc) */
128 char *saved_command_line;
129 /* Command line for parameter parsing */
130 static char *static_command_line;
131 /* Command line for per-initcall parameter parsing */
132 static char *initcall_command_line;
133 
134 static char *execute_command;
135 static char *ramdisk_execute_command;
136 
137 /*
138  * Used to generate warnings if static_key manipulation functions are used
139  * before jump_label_init is called.
140  */
141 bool static_key_initialized __read_mostly;
142 EXPORT_SYMBOL_GPL(static_key_initialized);
143 
144 /*
145  * If set, this is an indication to the drivers that reset the underlying
146  * device before going ahead with the initialization otherwise driver might
147  * rely on the BIOS and skip the reset operation.
148  *
149  * This is useful if kernel is booting in an unreliable environment.
150  * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
151  * skipped and devices will be in unknown state.
152  */
153 unsigned int reset_devices;
154 EXPORT_SYMBOL(reset_devices);
155 
156 static int __init set_reset_devices(char *str)
157 {
158         reset_devices = 1;
159         return 1;
160 }
161 
162 __setup("reset_devices", set_reset_devices);
163 
164 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
165 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
166 static const char *panic_later, *panic_param;
167 
168 extern const struct obs_kernel_param __setup_start[], __setup_end[];
169 
170 static int __init obsolete_checksetup(char *line)
171 {
172         const struct obs_kernel_param *p;
173         int had_early_param = 0;
174 
175         p = __setup_start;
176         do {
177                 int n = strlen(p->str);
178                 if (parameqn(line, p->str, n)) {
179                         if (p->early) {
180                                 /* Already done in parse_early_param?
181                                  * (Needs exact match on param part).
182                                  * Keep iterating, as we can have early
183                                  * params and __setups of same names 8( */
184                                 if (line[n] == '\0' || line[n] == '=')
185                                         had_early_param = 1;
186                         } else if (!p->setup_func) {
187                                 pr_warn("Parameter %s is obsolete, ignored\n",
188                                         p->str);
189                                 return 1;
190                         } else if (p->setup_func(line + n))
191                                 return 1;
192                 }
193                 p++;
194         } while (p < __setup_end);
195 
196         return had_early_param;
197 }
198 
199 /*
200  * This should be approx 2 Bo*oMips to start (note initial shift), and will
201  * still work even if initially too large, it will just take slightly longer
202  */
203 unsigned long loops_per_jiffy = (1<<12);
204 EXPORT_SYMBOL(loops_per_jiffy);
205 
206 static int __init debug_kernel(char *str)
207 {
208         console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
209         return 0;
210 }
211 
212 static int __init quiet_kernel(char *str)
213 {
214         console_loglevel = CONSOLE_LOGLEVEL_QUIET;
215         return 0;
216 }
217 
218 early_param("debug", debug_kernel);
219 early_param("quiet", quiet_kernel);
220 
221 static int __init loglevel(char *str)
222 {
223         int newlevel;
224 
225         /*
226          * Only update loglevel value when a correct setting was passed,
227          * to prevent blind crashes (when loglevel being set to 0) that
228          * are quite hard to debug
229          */
230         if (get_option(&str, &newlevel)) {
231                 console_loglevel = newlevel;
232                 return 0;
233         }
234 
235         return -EINVAL;
236 }
237 
238 early_param("loglevel", loglevel);
239 
240 /* Change NUL term back to "=", to make "param" the whole string. */
241 static int __init repair_env_string(char *param, char *val, const char *unused)
242 {
243         if (val) {
244                 /* param=val or param="val"? */
245                 if (val == param+strlen(param)+1)
246                         val[-1] = '=';
247                 else if (val == param+strlen(param)+2) {
248                         val[-2] = '=';
249                         memmove(val-1, val, strlen(val)+1);
250                         val--;
251                 } else
252                         BUG();
253         }
254         return 0;
255 }
256 
257 /* Anything after -- gets handed straight to init. */
258 static int __init set_init_arg(char *param, char *val, const char *unused)
259 {
260         unsigned int i;
261 
262         if (panic_later)
263                 return 0;
264 
265         repair_env_string(param, val, unused);
266 
267         for (i = 0; argv_init[i]; i++) {
268                 if (i == MAX_INIT_ARGS) {
269                         panic_later = "init";
270                         panic_param = param;
271                         return 0;
272                 }
273         }
274         argv_init[i] = param;
275         return 0;
276 }
277 
278 /*
279  * Unknown boot options get handed to init, unless they look like
280  * unused parameters (modprobe will find them in /proc/cmdline).
281  */
282 static int __init unknown_bootoption(char *param, char *val, const char *unused)
283 {
284         repair_env_string(param, val, unused);
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 #ifdef CONFIG_X86_LOCAL_APIC
355 static void __init smp_init(void)
356 {
357         APIC_init_uniprocessor();
358 }
359 #else
360 #define smp_init()      do { } while (0)
361 #endif
362 
363 static inline void setup_nr_cpu_ids(void) { }
364 static inline void smp_prepare_cpus(unsigned int maxcpus) { }
365 #endif
366 
367 /*
368  * We need to store the untouched command line for future reference.
369  * We also need to store the touched command line since the parameter
370  * parsing is performed in place, and we should allow a component to
371  * store reference of name/value for future reference.
372  */
373 static void __init setup_command_line(char *command_line)
374 {
375         saved_command_line =
376                 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
377         initcall_command_line =
378                 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
379         static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0);
380         strcpy(saved_command_line, boot_command_line);
381         strcpy(static_command_line, command_line);
382 }
383 
384 /*
385  * We need to finalize in a non-__init function or else race conditions
386  * between the root thread and the init thread may cause start_kernel to
387  * be reaped by free_initmem before the root thread has proceeded to
388  * cpu_idle.
389  *
390  * gcc-3.4 accidentally inlines this function, so use noinline.
391  */
392 
393 static __initdata DECLARE_COMPLETION(kthreadd_done);
394 
395 static noinline void __init_refok rest_init(void)
396 {
397         int pid;
398 
399         rcu_scheduler_starting();
400         /*
401          * We need to spawn init first so that it obtains pid 1, however
402          * the init task will end up wanting to create kthreads, which, if
403          * we schedule it before we create kthreadd, will OOPS.
404          */
405         kernel_thread(kernel_init, NULL, CLONE_FS);
406         numa_default_policy();
407         pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
408         rcu_read_lock();
409         kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
410         rcu_read_unlock();
411         complete(&kthreadd_done);
412 
413         /*
414          * The boot idle thread must execute schedule()
415          * at least once to get things moving:
416          */
417         init_idle_bootup_task(current);
418         schedule_preempt_disabled();
419         /* Call into cpu_idle with preempt disabled */
420         cpu_startup_entry(CPUHP_ONLINE);
421 }
422 
423 /* Check for early params. */
424 static int __init do_early_param(char *param, char *val, const char *unused)
425 {
426         const struct obs_kernel_param *p;
427 
428         for (p = __setup_start; p < __setup_end; p++) {
429                 if ((p->early && parameq(param, p->str)) ||
430                     (strcmp(param, "console") == 0 &&
431                      strcmp(p->str, "earlycon") == 0)
432                 ) {
433                         if (p->setup_func(val) != 0)
434                                 pr_warn("Malformed early option '%s'\n", param);
435                 }
436         }
437         /* We accept everything at this stage. */
438         return 0;
439 }
440 
441 void __init parse_early_options(char *cmdline)
442 {
443         parse_args("early options", cmdline, NULL, 0, 0, 0, do_early_param);
444 }
445 
446 /* Arch code calls this early on, or if not, just before other parsing. */
447 void __init parse_early_param(void)
448 {
449         static int done __initdata;
450         static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
451 
452         if (done)
453                 return;
454 
455         /* All fall through to do_early_param. */
456         strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
457         parse_early_options(tmp_cmdline);
458         done = 1;
459 }
460 
461 /*
462  *      Activate the first processor.
463  */
464 
465 static void __init boot_cpu_init(void)
466 {
467         int cpu = smp_processor_id();
468         /* Mark the boot cpu "present", "online" etc for SMP and UP case */
469         set_cpu_online(cpu, true);
470         set_cpu_active(cpu, true);
471         set_cpu_present(cpu, true);
472         set_cpu_possible(cpu, true);
473 }
474 
475 void __init __weak smp_setup_processor_id(void)
476 {
477 }
478 
479 # if THREAD_SIZE >= PAGE_SIZE
480 void __init __weak thread_info_cache_init(void)
481 {
482 }
483 #endif
484 
485 /*
486  * Set up kernel memory allocators
487  */
488 static void __init mm_init(void)
489 {
490         /*
491          * page_ext requires contiguous pages,
492          * bigger than MAX_ORDER unless SPARSEMEM.
493          */
494         page_ext_init_flatmem();
495         mem_init();
496         kmem_cache_init();
497         percpu_init_late();
498         pgtable_init();
499         vmalloc_init();
500 }
501 
502 asmlinkage __visible void __init start_kernel(void)
503 {
504         char *command_line;
505         char *after_dashes;
506 
507         /*
508          * Need to run as early as possible, to initialize the
509          * lockdep hash:
510          */
511         lockdep_init();
512         set_task_stack_end_magic(&init_task);
513         smp_setup_processor_id();
514         debug_objects_early_init();
515 
516         /*
517          * Set up the the initial canary ASAP:
518          */
519         boot_init_stack_canary();
520 
521         cgroup_init_early();
522 
523         local_irq_disable();
524         early_boot_irqs_disabled = true;
525 
526 /*
527  * Interrupts are still disabled. Do necessary setups, then
528  * enable them
529  */
530         boot_cpu_init();
531         page_address_init();
532         pr_notice("%s", linux_banner);
533         setup_arch(&command_line);
534         mm_init_cpumask(&init_mm);
535         setup_command_line(command_line);
536         setup_nr_cpu_ids();
537         setup_per_cpu_areas();
538         smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
539 
540         build_all_zonelists(NULL, NULL);
541         page_alloc_init();
542 
543         pr_notice("Kernel command line: %s\n", boot_command_line);
544         parse_early_param();
545         after_dashes = parse_args("Booting kernel",
546                                   static_command_line, __start___param,
547                                   __stop___param - __start___param,
548                                   -1, -1, &unknown_bootoption);
549         if (!IS_ERR_OR_NULL(after_dashes))
550                 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
551                            set_init_arg);
552 
553         jump_label_init();
554 
555         /*
556          * These use large bootmem allocations and must precede
557          * kmem_cache_init()
558          */
559         setup_log_buf(0);
560         pidhash_init();
561         vfs_caches_init_early();
562         sort_main_extable();
563         trap_init();
564         mm_init();
565 
566         /*
567          * Set up the scheduler prior starting any interrupts (such as the
568          * timer interrupt). Full topology setup happens at smp_init()
569          * time - but meanwhile we still have a functioning scheduler.
570          */
571         sched_init();
572         /*
573          * Disable preemption - early bootup scheduling is extremely
574          * fragile until we cpu_idle() for the first time.
575          */
576         preempt_disable();
577         if (WARN(!irqs_disabled(),
578                  "Interrupts were enabled *very* early, fixing it\n"))
579                 local_irq_disable();
580         idr_init_cache();
581         rcu_init();
582 
583         /* trace_printk() and trace points may be used after this */
584         trace_init();
585 
586         context_tracking_init();
587         radix_tree_init();
588         /* init some links before init_ISA_irqs() */
589         early_irq_init();
590         init_IRQ();
591         tick_init();
592         rcu_init_nohz();
593         init_timers();
594         hrtimers_init();
595         softirq_init();
596         timekeeping_init();
597         time_init();
598         sched_clock_postinit();
599         perf_event_init();
600         profile_init();
601         call_function_init();
602         WARN(!irqs_disabled(), "Interrupts were enabled early\n");
603         early_boot_irqs_disabled = false;
604         local_irq_enable();
605 
606         kmem_cache_init_late();
607 
608         /*
609          * HACK ALERT! This is early. We're enabling the console before
610          * we've done PCI setups etc, and console_init() must be aware of
611          * this. But we do want output early, in case something goes wrong.
612          */
613         console_init();
614         if (panic_later)
615                 panic("Too many boot %s vars at `%s'", panic_later,
616                       panic_param);
617 
618         lockdep_info();
619 
620         /*
621          * Need to run this when irqs are enabled, because it wants
622          * to self-test [hard/soft]-irqs on/off lock inversion bugs
623          * too:
624          */
625         locking_selftest();
626 
627 #ifdef CONFIG_BLK_DEV_INITRD
628         if (initrd_start && !initrd_below_start_ok &&
629             page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
630                 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
631                     page_to_pfn(virt_to_page((void *)initrd_start)),
632                     min_low_pfn);
633                 initrd_start = 0;
634         }
635 #endif
636         page_ext_init();
637         debug_objects_mem_init();
638         kmemleak_init();
639         setup_per_cpu_pageset();
640         numa_policy_init();
641         if (late_time_init)
642                 late_time_init();
643         sched_clock_init();
644         calibrate_delay();
645         pidmap_init();
646         anon_vma_init();
647         acpi_early_init();
648 #ifdef CONFIG_X86
649         if (efi_enabled(EFI_RUNTIME_SERVICES))
650                 efi_enter_virtual_mode();
651 #endif
652 #ifdef CONFIG_X86_ESPFIX64
653         /* Should be run before the first non-init thread is created */
654         init_espfix_bsp();
655 #endif
656         thread_info_cache_init();
657         cred_init();
658         fork_init(totalram_pages);
659         proc_caches_init();
660         buffer_init();
661         key_init();
662         security_init();
663         dbg_late_init();
664         vfs_caches_init(totalram_pages);
665         signals_init();
666         /* rootfs populating might need page-writeback */
667         page_writeback_init();
668         proc_root_init();
669         nsfs_init();
670         cgroup_init();
671         cpuset_init();
672         taskstats_init_early();
673         delayacct_init();
674 
675         check_bugs();
676 
677         sfi_init_late();
678 
679         if (efi_enabled(EFI_RUNTIME_SERVICES)) {
680                 efi_late_init();
681                 efi_free_boot_services();
682         }
683 
684         ftrace_init();
685 
686         /* Do the rest non-__init'ed, we're now alive */
687         rest_init();
688 }
689 
690 /* Call all constructor functions linked into the kernel. */
691 static void __init do_ctors(void)
692 {
693 #ifdef CONFIG_CONSTRUCTORS
694         ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
695 
696         for (; fn < (ctor_fn_t *) __ctors_end; fn++)
697                 (*fn)();
698 #endif
699 }
700 
701 bool initcall_debug;
702 core_param(initcall_debug, initcall_debug, bool, 0644);
703 
704 #ifdef CONFIG_KALLSYMS
705 struct blacklist_entry {
706         struct list_head next;
707         char *buf;
708 };
709 
710 static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
711 
712 static int __init initcall_blacklist(char *str)
713 {
714         char *str_entry;
715         struct blacklist_entry *entry;
716 
717         /* str argument is a comma-separated list of functions */
718         do {
719                 str_entry = strsep(&str, ",");
720                 if (str_entry) {
721                         pr_debug("blacklisting initcall %s\n", str_entry);
722                         entry = alloc_bootmem(sizeof(*entry));
723                         entry->buf = alloc_bootmem(strlen(str_entry) + 1);
724                         strcpy(entry->buf, str_entry);
725                         list_add(&entry->next, &blacklisted_initcalls);
726                 }
727         } while (str_entry);
728 
729         return 0;
730 }
731 
732 static bool __init_or_module initcall_blacklisted(initcall_t fn)
733 {
734         struct list_head *tmp;
735         struct blacklist_entry *entry;
736         char *fn_name;
737 
738         fn_name = kasprintf(GFP_KERNEL, "%pf", fn);
739         if (!fn_name)
740                 return false;
741 
742         list_for_each(tmp, &blacklisted_initcalls) {
743                 entry = list_entry(tmp, struct blacklist_entry, next);
744                 if (!strcmp(fn_name, entry->buf)) {
745                         pr_debug("initcall %s blacklisted\n", fn_name);
746                         kfree(fn_name);
747                         return true;
748                 }
749         }
750 
751         kfree(fn_name);
752         return false;
753 }
754 #else
755 static int __init initcall_blacklist(char *str)
756 {
757         pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
758         return 0;
759 }
760 
761 static bool __init_or_module initcall_blacklisted(initcall_t fn)
762 {
763         return false;
764 }
765 #endif
766 __setup("initcall_blacklist=", initcall_blacklist);
767 
768 static int __init_or_module do_one_initcall_debug(initcall_t fn)
769 {
770         ktime_t calltime, delta, rettime;
771         unsigned long long duration;
772         int ret;
773 
774         printk(KERN_DEBUG "calling  %pF @ %i\n", fn, task_pid_nr(current));
775         calltime = ktime_get();
776         ret = fn();
777         rettime = ktime_get();
778         delta = ktime_sub(rettime, calltime);
779         duration = (unsigned long long) ktime_to_ns(delta) >> 10;
780         printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n",
781                  fn, ret, duration);
782 
783         return ret;
784 }
785 
786 int __init_or_module do_one_initcall(initcall_t fn)
787 {
788         int count = preempt_count();
789         int ret;
790         char msgbuf[64];
791 
792         if (initcall_blacklisted(fn))
793                 return -EPERM;
794 
795         if (initcall_debug)
796                 ret = do_one_initcall_debug(fn);
797         else
798                 ret = fn();
799 
800         msgbuf[0] = 0;
801 
802         if (preempt_count() != count) {
803                 sprintf(msgbuf, "preemption imbalance ");
804                 preempt_count_set(count);
805         }
806         if (irqs_disabled()) {
807                 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
808                 local_irq_enable();
809         }
810         WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
811 
812         return ret;
813 }
814 
815 
816 extern initcall_t __initcall_start[];
817 extern initcall_t __initcall0_start[];
818 extern initcall_t __initcall1_start[];
819 extern initcall_t __initcall2_start[];
820 extern initcall_t __initcall3_start[];
821 extern initcall_t __initcall4_start[];
822 extern initcall_t __initcall5_start[];
823 extern initcall_t __initcall6_start[];
824 extern initcall_t __initcall7_start[];
825 extern initcall_t __initcall_end[];
826 
827 static initcall_t *initcall_levels[] __initdata = {
828         __initcall0_start,
829         __initcall1_start,
830         __initcall2_start,
831         __initcall3_start,
832         __initcall4_start,
833         __initcall5_start,
834         __initcall6_start,
835         __initcall7_start,
836         __initcall_end,
837 };
838 
839 /* Keep these in sync with initcalls in include/linux/init.h */
840 static char *initcall_level_names[] __initdata = {
841         "early",
842         "core",
843         "postcore",
844         "arch",
845         "subsys",
846         "fs",
847         "device",
848         "late",
849 };
850 
851 static void __init do_initcall_level(int level)
852 {
853         initcall_t *fn;
854 
855         strcpy(initcall_command_line, saved_command_line);
856         parse_args(initcall_level_names[level],
857                    initcall_command_line, __start___param,
858                    __stop___param - __start___param,
859                    level, level,
860                    &repair_env_string);
861 
862         for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
863                 do_one_initcall(*fn);
864 }
865 
866 static void __init do_initcalls(void)
867 {
868         int level;
869 
870         for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
871                 do_initcall_level(level);
872 }
873 
874 /*
875  * Ok, the machine is now initialized. None of the devices
876  * have been touched yet, but the CPU subsystem is up and
877  * running, and memory and process management works.
878  *
879  * Now we can finally start doing some real work..
880  */
881 static void __init do_basic_setup(void)
882 {
883         cpuset_init_smp();
884         usermodehelper_init();
885         shmem_init();
886         driver_init();
887         init_irq_proc();
888         do_ctors();
889         usermodehelper_enable();
890         do_initcalls();
891         random_int_secret_init();
892 }
893 
894 static void __init do_pre_smp_initcalls(void)
895 {
896         initcall_t *fn;
897 
898         for (fn = __initcall_start; fn < __initcall0_start; fn++)
899                 do_one_initcall(*fn);
900 }
901 
902 /*
903  * This function requests modules which should be loaded by default and is
904  * called twice right after initrd is mounted and right before init is
905  * exec'd.  If such modules are on either initrd or rootfs, they will be
906  * loaded before control is passed to userland.
907  */
908 void __init load_default_modules(void)
909 {
910         load_default_elevator_module();
911 }
912 
913 static int run_init_process(const char *init_filename)
914 {
915         argv_init[0] = init_filename;
916         return do_execve(getname_kernel(init_filename),
917                 (const char __user *const __user *)argv_init,
918                 (const char __user *const __user *)envp_init);
919 }
920 
921 static int try_to_run_init_process(const char *init_filename)
922 {
923         int ret;
924 
925         ret = run_init_process(init_filename);
926 
927         if (ret && ret != -ENOENT) {
928                 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
929                        init_filename, ret);
930         }
931 
932         return ret;
933 }
934 
935 static noinline void __init kernel_init_freeable(void);
936 
937 static int __ref kernel_init(void *unused)
938 {
939         int ret;
940 
941         kernel_init_freeable();
942         /* need to finish all async __init code before freeing the memory */
943         async_synchronize_full();
944         free_initmem();
945         mark_rodata_ro();
946         system_state = SYSTEM_RUNNING;
947         numa_default_policy();
948 
949         flush_delayed_fput();
950 
951         if (ramdisk_execute_command) {
952                 ret = run_init_process(ramdisk_execute_command);
953                 if (!ret)
954                         return 0;
955                 pr_err("Failed to execute %s (error %d)\n",
956                        ramdisk_execute_command, ret);
957         }
958 
959         /*
960          * We try each of these until one succeeds.
961          *
962          * The Bourne shell can be used instead of init if we are
963          * trying to recover a really broken machine.
964          */
965         if (execute_command) {
966                 ret = run_init_process(execute_command);
967                 if (!ret)
968                         return 0;
969 #ifndef CONFIG_INIT_FALLBACK
970                 panic("Requested init %s failed (error %d).",
971                       execute_command, ret);
972 #else
973                 pr_err("Failed to execute %s (error %d).  Attempting defaults...\n",
974                        execute_command, ret);
975 #endif
976         }
977         if (!try_to_run_init_process("/sbin/init") ||
978             !try_to_run_init_process("/etc/init") ||
979             !try_to_run_init_process("/bin/init") ||
980             !try_to_run_init_process("/bin/sh"))
981                 return 0;
982 
983         panic("No working init found.  Try passing init= option to kernel. "
984               "See Linux Documentation/init.txt for guidance.");
985 }
986 
987 static noinline void __init kernel_init_freeable(void)
988 {
989         /*
990          * Wait until kthreadd is all set-up.
991          */
992         wait_for_completion(&kthreadd_done);
993 
994         /* Now the scheduler is fully set up and can do blocking allocations */
995         gfp_allowed_mask = __GFP_BITS_MASK;
996 
997         /*
998          * init can allocate pages on any node
999          */
1000         set_mems_allowed(node_states[N_MEMORY]);
1001         /*
1002          * init can run on any cpu.
1003          */
1004         set_cpus_allowed_ptr(current, cpu_all_mask);
1005 
1006         cad_pid = task_pid(current);
1007 
1008         smp_prepare_cpus(setup_max_cpus);
1009 
1010         do_pre_smp_initcalls();
1011         lockup_detector_init();
1012 
1013         smp_init();
1014         sched_init_smp();
1015 
1016         do_basic_setup();
1017 
1018         /* Open the /dev/console on the rootfs, this should never fail */
1019         if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
1020                 pr_err("Warning: unable to open an initial console.\n");
1021 
1022         (void) sys_dup(0);
1023         (void) sys_dup(0);
1024         /*
1025          * check if there is an early userspace init.  If yes, let it do all
1026          * the work
1027          */
1028 
1029         if (!ramdisk_execute_command)
1030                 ramdisk_execute_command = "/init";
1031 
1032         if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
1033                 ramdisk_execute_command = NULL;
1034                 prepare_namespace();
1035         }
1036 
1037         /*
1038          * Ok, we have completed the initial bootup, and
1039          * we're essentially up and running. Get rid of the
1040          * initmem segments and start the user-mode stuff..
1041          *
1042          * rootfs is available now, try loading the public keys
1043          * and default modules
1044          */
1045 
1046         integrity_load_keys();
1047         load_default_modules();
1048 }
1049 

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