Version:  2.0.40 2.2.26 2.4.37 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8

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 #include <linux/io.h>
 84 
 85 #include <asm/io.h>
 86 #include <asm/bugs.h>
 87 #include <asm/setup.h>
 88 #include <asm/sections.h>
 89 #include <asm/cacheflush.h>
 90 
 91 static int kernel_init(void *);
 92 
 93 extern void init_IRQ(void);
 94 extern void fork_init(void);
 95 extern void radix_tree_init(void);
 96 
 97 /*
 98  * Debug helper: via this flag we know that we are in 'early bootup code'
 99  * where only the boot processor is running with IRQ disabled.  This means
100  * two things - IRQ must not be enabled before the flag is cleared and some
101  * operations which are not allowed with IRQ disabled are allowed while the
102  * flag is set.
103  */
104 bool early_boot_irqs_disabled __read_mostly;
105 
106 enum system_states system_state __read_mostly;
107 EXPORT_SYMBOL(system_state);
108 
109 /*
110  * Boot command-line arguments
111  */
112 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
113 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
114 
115 extern void time_init(void);
116 /* Default late time init is NULL. archs can override this later. */
117 void (*__initdata late_time_init)(void);
118 
119 /* Untouched command line saved by arch-specific code. */
120 char __initdata boot_command_line[COMMAND_LINE_SIZE];
121 /* Untouched saved command line (eg. for /proc) */
122 char *saved_command_line;
123 /* Command line for parameter parsing */
124 static char *static_command_line;
125 /* Command line for per-initcall parameter parsing */
126 static char *initcall_command_line;
127 
128 static char *execute_command;
129 static char *ramdisk_execute_command;
130 
131 /*
132  * Used to generate warnings if static_key manipulation functions are used
133  * before jump_label_init is called.
134  */
135 bool static_key_initialized __read_mostly;
136 EXPORT_SYMBOL_GPL(static_key_initialized);
137 
138 /*
139  * If set, this is an indication to the drivers that reset the underlying
140  * device before going ahead with the initialization otherwise driver might
141  * rely on the BIOS and skip the reset operation.
142  *
143  * This is useful if kernel is booting in an unreliable environment.
144  * For ex. kdump situation where previous kernel has crashed, BIOS has been
145  * skipped and devices will be in unknown state.
146  */
147 unsigned int reset_devices;
148 EXPORT_SYMBOL(reset_devices);
149 
150 static int __init set_reset_devices(char *str)
151 {
152         reset_devices = 1;
153         return 1;
154 }
155 
156 __setup("reset_devices", set_reset_devices);
157 
158 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
159 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
160 static const char *panic_later, *panic_param;
161 
162 extern const struct obs_kernel_param __setup_start[], __setup_end[];
163 
164 static bool __init obsolete_checksetup(char *line)
165 {
166         const struct obs_kernel_param *p;
167         bool had_early_param = false;
168 
169         p = __setup_start;
170         do {
171                 int n = strlen(p->str);
172                 if (parameqn(line, p->str, n)) {
173                         if (p->early) {
174                                 /* Already done in parse_early_param?
175                                  * (Needs exact match on param part).
176                                  * Keep iterating, as we can have early
177                                  * params and __setups of same names 8( */
178                                 if (line[n] == '\0' || line[n] == '=')
179                                         had_early_param = true;
180                         } else if (!p->setup_func) {
181                                 pr_warn("Parameter %s is obsolete, ignored\n",
182                                         p->str);
183                                 return true;
184                         } else if (p->setup_func(line + n))
185                                 return true;
186                 }
187                 p++;
188         } while (p < __setup_end);
189 
190         return had_early_param;
191 }
192 
193 /*
194  * This should be approx 2 Bo*oMips to start (note initial shift), and will
195  * still work even if initially too large, it will just take slightly longer
196  */
197 unsigned long loops_per_jiffy = (1<<12);
198 EXPORT_SYMBOL(loops_per_jiffy);
199 
200 static int __init debug_kernel(char *str)
201 {
202         console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
203         return 0;
204 }
205 
206 static int __init quiet_kernel(char *str)
207 {
208         console_loglevel = CONSOLE_LOGLEVEL_QUIET;
209         return 0;
210 }
211 
212 early_param("debug", debug_kernel);
213 early_param("quiet", quiet_kernel);
214 
215 static int __init loglevel(char *str)
216 {
217         int newlevel;
218 
219         /*
220          * Only update loglevel value when a correct setting was passed,
221          * to prevent blind crashes (when loglevel being set to 0) that
222          * are quite hard to debug
223          */
224         if (get_option(&str, &newlevel)) {
225                 console_loglevel = newlevel;
226                 return 0;
227         }
228 
229         return -EINVAL;
230 }
231 
232 early_param("loglevel", loglevel);
233 
234 /* Change NUL term back to "=", to make "param" the whole string. */
235 static int __init repair_env_string(char *param, char *val,
236                                     const char *unused, void *arg)
237 {
238         if (val) {
239                 /* param=val or param="val"? */
240                 if (val == param+strlen(param)+1)
241                         val[-1] = '=';
242                 else if (val == param+strlen(param)+2) {
243                         val[-2] = '=';
244                         memmove(val-1, val, strlen(val)+1);
245                         val--;
246                 } else
247                         BUG();
248         }
249         return 0;
250 }
251 
252 /* Anything after -- gets handed straight to init. */
253 static int __init set_init_arg(char *param, char *val,
254                                const char *unused, void *arg)
255 {
256         unsigned int i;
257 
258         if (panic_later)
259                 return 0;
260 
261         repair_env_string(param, val, unused, NULL);
262 
263         for (i = 0; argv_init[i]; i++) {
264                 if (i == MAX_INIT_ARGS) {
265                         panic_later = "init";
266                         panic_param = param;
267                         return 0;
268                 }
269         }
270         argv_init[i] = param;
271         return 0;
272 }
273 
274 /*
275  * Unknown boot options get handed to init, unless they look like
276  * unused parameters (modprobe will find them in /proc/cmdline).
277  */
278 static int __init unknown_bootoption(char *param, char *val,
279                                      const char *unused, void *arg)
280 {
281         repair_env_string(param, val, unused, NULL);
282 
283         /* Handle obsolete-style parameters */
284         if (obsolete_checksetup(param))
285                 return 0;
286 
287         /* Unused module parameter. */
288         if (strchr(param, '.') && (!val || strchr(param, '.') < val))
289                 return 0;
290 
291         if (panic_later)
292                 return 0;
293 
294         if (val) {
295                 /* Environment option */
296                 unsigned int i;
297                 for (i = 0; envp_init[i]; i++) {
298                         if (i == MAX_INIT_ENVS) {
299                                 panic_later = "env";
300                                 panic_param = param;
301                         }
302                         if (!strncmp(param, envp_init[i], val - param))
303                                 break;
304                 }
305                 envp_init[i] = param;
306         } else {
307                 /* Command line option */
308                 unsigned int i;
309                 for (i = 0; argv_init[i]; i++) {
310                         if (i == MAX_INIT_ARGS) {
311                                 panic_later = "init";
312                                 panic_param = param;
313                         }
314                 }
315                 argv_init[i] = param;
316         }
317         return 0;
318 }
319 
320 static int __init init_setup(char *str)
321 {
322         unsigned int i;
323 
324         execute_command = str;
325         /*
326          * In case LILO is going to boot us with default command line,
327          * it prepends "auto" before the whole cmdline which makes
328          * the shell think it should execute a script with such name.
329          * So we ignore all arguments entered _before_ init=... [MJ]
330          */
331         for (i = 1; i < MAX_INIT_ARGS; i++)
332                 argv_init[i] = NULL;
333         return 1;
334 }
335 __setup("init=", init_setup);
336 
337 static int __init rdinit_setup(char *str)
338 {
339         unsigned int i;
340 
341         ramdisk_execute_command = str;
342         /* See "auto" comment in init_setup */
343         for (i = 1; i < MAX_INIT_ARGS; i++)
344                 argv_init[i] = NULL;
345         return 1;
346 }
347 __setup("rdinit=", rdinit_setup);
348 
349 #ifndef CONFIG_SMP
350 static const unsigned int setup_max_cpus = NR_CPUS;
351 static inline void setup_nr_cpu_ids(void) { }
352 static inline void smp_prepare_cpus(unsigned int maxcpus) { }
353 #endif
354 
355 /*
356  * We need to store the untouched command line for future reference.
357  * We also need to store the touched command line since the parameter
358  * parsing is performed in place, and we should allow a component to
359  * store reference of name/value for future reference.
360  */
361 static void __init setup_command_line(char *command_line)
362 {
363         saved_command_line =
364                 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
365         initcall_command_line =
366                 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
367         static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0);
368         strcpy(saved_command_line, boot_command_line);
369         strcpy(static_command_line, command_line);
370 }
371 
372 /*
373  * We need to finalize in a non-__init function or else race conditions
374  * between the root thread and the init thread may cause start_kernel to
375  * be reaped by free_initmem before the root thread has proceeded to
376  * cpu_idle.
377  *
378  * gcc-3.4 accidentally inlines this function, so use noinline.
379  */
380 
381 static __initdata DECLARE_COMPLETION(kthreadd_done);
382 
383 static noinline void __ref rest_init(void)
384 {
385         int pid;
386 
387         rcu_scheduler_starting();
388         /*
389          * We need to spawn init first so that it obtains pid 1, however
390          * the init task will end up wanting to create kthreads, which, if
391          * we schedule it before we create kthreadd, will OOPS.
392          */
393         kernel_thread(kernel_init, NULL, CLONE_FS);
394         numa_default_policy();
395         pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
396         rcu_read_lock();
397         kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
398         rcu_read_unlock();
399         complete(&kthreadd_done);
400 
401         /*
402          * The boot idle thread must execute schedule()
403          * at least once to get things moving:
404          */
405         init_idle_bootup_task(current);
406         schedule_preempt_disabled();
407         /* Call into cpu_idle with preempt disabled */
408         cpu_startup_entry(CPUHP_ONLINE);
409 }
410 
411 /* Check for early params. */
412 static int __init do_early_param(char *param, char *val,
413                                  const char *unused, void *arg)
414 {
415         const struct obs_kernel_param *p;
416 
417         for (p = __setup_start; p < __setup_end; p++) {
418                 if ((p->early && parameq(param, p->str)) ||
419                     (strcmp(param, "console") == 0 &&
420                      strcmp(p->str, "earlycon") == 0)
421                 ) {
422                         if (p->setup_func(val) != 0)
423                                 pr_warn("Malformed early option '%s'\n", param);
424                 }
425         }
426         /* We accept everything at this stage. */
427         return 0;
428 }
429 
430 void __init parse_early_options(char *cmdline)
431 {
432         parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
433                    do_early_param);
434 }
435 
436 /* Arch code calls this early on, or if not, just before other parsing. */
437 void __init parse_early_param(void)
438 {
439         static int done __initdata;
440         static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
441 
442         if (done)
443                 return;
444 
445         /* All fall through to do_early_param. */
446         strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
447         parse_early_options(tmp_cmdline);
448         done = 1;
449 }
450 
451 void __init __weak smp_setup_processor_id(void)
452 {
453 }
454 
455 # if THREAD_SIZE >= PAGE_SIZE
456 void __init __weak thread_stack_cache_init(void)
457 {
458 }
459 #endif
460 
461 /*
462  * Set up kernel memory allocators
463  */
464 static void __init mm_init(void)
465 {
466         /*
467          * page_ext requires contiguous pages,
468          * bigger than MAX_ORDER unless SPARSEMEM.
469          */
470         page_ext_init_flatmem();
471         mem_init();
472         kmem_cache_init();
473         percpu_init_late();
474         pgtable_init();
475         vmalloc_init();
476         ioremap_huge_init();
477 }
478 
479 asmlinkage __visible void __init start_kernel(void)
480 {
481         char *command_line;
482         char *after_dashes;
483 
484         set_task_stack_end_magic(&init_task);
485         smp_setup_processor_id();
486         debug_objects_early_init();
487 
488         /*
489          * Set up the the initial canary ASAP:
490          */
491         boot_init_stack_canary();
492 
493         cgroup_init_early();
494 
495         local_irq_disable();
496         early_boot_irqs_disabled = true;
497 
498 /*
499  * Interrupts are still disabled. Do necessary setups, then
500  * enable them
501  */
502         boot_cpu_init();
503         page_address_init();
504         pr_notice("%s", linux_banner);
505         setup_arch(&command_line);
506         mm_init_cpumask(&init_mm);
507         setup_command_line(command_line);
508         setup_nr_cpu_ids();
509         setup_per_cpu_areas();
510         boot_cpu_state_init();
511         smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
512 
513         build_all_zonelists(NULL, NULL);
514         page_alloc_init();
515 
516         pr_notice("Kernel command line: %s\n", boot_command_line);
517         parse_early_param();
518         after_dashes = parse_args("Booting kernel",
519                                   static_command_line, __start___param,
520                                   __stop___param - __start___param,
521                                   -1, -1, NULL, &unknown_bootoption);
522         if (!IS_ERR_OR_NULL(after_dashes))
523                 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
524                            NULL, set_init_arg);
525 
526         jump_label_init();
527 
528         /*
529          * These use large bootmem allocations and must precede
530          * kmem_cache_init()
531          */
532         setup_log_buf(0);
533         pidhash_init();
534         vfs_caches_init_early();
535         sort_main_extable();
536         trap_init();
537         mm_init();
538 
539         /*
540          * Set up the scheduler prior starting any interrupts (such as the
541          * timer interrupt). Full topology setup happens at smp_init()
542          * time - but meanwhile we still have a functioning scheduler.
543          */
544         sched_init();
545         /*
546          * Disable preemption - early bootup scheduling is extremely
547          * fragile until we cpu_idle() for the first time.
548          */
549         preempt_disable();
550         if (WARN(!irqs_disabled(),
551                  "Interrupts were enabled *very* early, fixing it\n"))
552                 local_irq_disable();
553         idr_init_cache();
554         rcu_init();
555 
556         /* trace_printk() and trace points may be used after this */
557         trace_init();
558 
559         context_tracking_init();
560         radix_tree_init();
561         /* init some links before init_ISA_irqs() */
562         early_irq_init();
563         init_IRQ();
564         tick_init();
565         rcu_init_nohz();
566         init_timers();
567         hrtimers_init();
568         softirq_init();
569         timekeeping_init();
570         time_init();
571         sched_clock_postinit();
572         printk_nmi_init();
573         perf_event_init();
574         profile_init();
575         call_function_init();
576         WARN(!irqs_disabled(), "Interrupts were enabled early\n");
577         early_boot_irqs_disabled = false;
578         local_irq_enable();
579 
580         kmem_cache_init_late();
581 
582         /*
583          * HACK ALERT! This is early. We're enabling the console before
584          * we've done PCI setups etc, and console_init() must be aware of
585          * this. But we do want output early, in case something goes wrong.
586          */
587         console_init();
588         if (panic_later)
589                 panic("Too many boot %s vars at `%s'", panic_later,
590                       panic_param);
591 
592         lockdep_info();
593 
594         /*
595          * Need to run this when irqs are enabled, because it wants
596          * to self-test [hard/soft]-irqs on/off lock inversion bugs
597          * too:
598          */
599         locking_selftest();
600 
601 #ifdef CONFIG_BLK_DEV_INITRD
602         if (initrd_start && !initrd_below_start_ok &&
603             page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
604                 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
605                     page_to_pfn(virt_to_page((void *)initrd_start)),
606                     min_low_pfn);
607                 initrd_start = 0;
608         }
609 #endif
610         page_ext_init();
611         debug_objects_mem_init();
612         kmemleak_init();
613         setup_per_cpu_pageset();
614         numa_policy_init();
615         if (late_time_init)
616                 late_time_init();
617         sched_clock_init();
618         calibrate_delay();
619         pidmap_init();
620         anon_vma_init();
621         acpi_early_init();
622 #ifdef CONFIG_X86
623         if (efi_enabled(EFI_RUNTIME_SERVICES))
624                 efi_enter_virtual_mode();
625 #endif
626 #ifdef CONFIG_X86_ESPFIX64
627         /* Should be run before the first non-init thread is created */
628         init_espfix_bsp();
629 #endif
630         thread_stack_cache_init();
631         cred_init();
632         fork_init();
633         proc_caches_init();
634         buffer_init();
635         key_init();
636         security_init();
637         dbg_late_init();
638         vfs_caches_init();
639         signals_init();
640         /* rootfs populating might need page-writeback */
641         page_writeback_init();
642         proc_root_init();
643         nsfs_init();
644         cpuset_init();
645         cgroup_init();
646         taskstats_init_early();
647         delayacct_init();
648 
649         check_bugs();
650 
651         acpi_subsystem_init();
652         sfi_init_late();
653 
654         if (efi_enabled(EFI_RUNTIME_SERVICES)) {
655                 efi_late_init();
656                 efi_free_boot_services();
657         }
658 
659         ftrace_init();
660 
661         /* Do the rest non-__init'ed, we're now alive */
662         rest_init();
663 }
664 
665 /* Call all constructor functions linked into the kernel. */
666 static void __init do_ctors(void)
667 {
668 #ifdef CONFIG_CONSTRUCTORS
669         ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
670 
671         for (; fn < (ctor_fn_t *) __ctors_end; fn++)
672                 (*fn)();
673 #endif
674 }
675 
676 bool initcall_debug;
677 core_param(initcall_debug, initcall_debug, bool, 0644);
678 
679 #ifdef CONFIG_KALLSYMS
680 struct blacklist_entry {
681         struct list_head next;
682         char *buf;
683 };
684 
685 static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
686 
687 static int __init initcall_blacklist(char *str)
688 {
689         char *str_entry;
690         struct blacklist_entry *entry;
691 
692         /* str argument is a comma-separated list of functions */
693         do {
694                 str_entry = strsep(&str, ",");
695                 if (str_entry) {
696                         pr_debug("blacklisting initcall %s\n", str_entry);
697                         entry = alloc_bootmem(sizeof(*entry));
698                         entry->buf = alloc_bootmem(strlen(str_entry) + 1);
699                         strcpy(entry->buf, str_entry);
700                         list_add(&entry->next, &blacklisted_initcalls);
701                 }
702         } while (str_entry);
703 
704         return 0;
705 }
706 
707 static bool __init_or_module initcall_blacklisted(initcall_t fn)
708 {
709         struct blacklist_entry *entry;
710         char fn_name[KSYM_SYMBOL_LEN];
711         unsigned long addr;
712 
713         if (list_empty(&blacklisted_initcalls))
714                 return false;
715 
716         addr = (unsigned long) dereference_function_descriptor(fn);
717         sprint_symbol_no_offset(fn_name, addr);
718 
719         /*
720          * fn will be "function_name [module_name]" where [module_name] is not
721          * displayed for built-in init functions.  Strip off the [module_name].
722          */
723         strreplace(fn_name, ' ', '\0');
724 
725         list_for_each_entry(entry, &blacklisted_initcalls, next) {
726                 if (!strcmp(fn_name, entry->buf)) {
727                         pr_debug("initcall %s blacklisted\n", fn_name);
728                         return true;
729                 }
730         }
731 
732         return false;
733 }
734 #else
735 static int __init initcall_blacklist(char *str)
736 {
737         pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
738         return 0;
739 }
740 
741 static bool __init_or_module initcall_blacklisted(initcall_t fn)
742 {
743         return false;
744 }
745 #endif
746 __setup("initcall_blacklist=", initcall_blacklist);
747 
748 static int __init_or_module do_one_initcall_debug(initcall_t fn)
749 {
750         ktime_t calltime, delta, rettime;
751         unsigned long long duration;
752         int ret;
753 
754         printk(KERN_DEBUG "calling  %pF @ %i\n", fn, task_pid_nr(current));
755         calltime = ktime_get();
756         ret = fn();
757         rettime = ktime_get();
758         delta = ktime_sub(rettime, calltime);
759         duration = (unsigned long long) ktime_to_ns(delta) >> 10;
760         printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n",
761                  fn, ret, duration);
762 
763         return ret;
764 }
765 
766 int __init_or_module do_one_initcall(initcall_t fn)
767 {
768         int count = preempt_count();
769         int ret;
770         char msgbuf[64];
771 
772         if (initcall_blacklisted(fn))
773                 return -EPERM;
774 
775         if (initcall_debug)
776                 ret = do_one_initcall_debug(fn);
777         else
778                 ret = fn();
779 
780         msgbuf[0] = 0;
781 
782         if (preempt_count() != count) {
783                 sprintf(msgbuf, "preemption imbalance ");
784                 preempt_count_set(count);
785         }
786         if (irqs_disabled()) {
787                 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
788                 local_irq_enable();
789         }
790         WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
791 
792         return ret;
793 }
794 
795 
796 extern initcall_t __initcall_start[];
797 extern initcall_t __initcall0_start[];
798 extern initcall_t __initcall1_start[];
799 extern initcall_t __initcall2_start[];
800 extern initcall_t __initcall3_start[];
801 extern initcall_t __initcall4_start[];
802 extern initcall_t __initcall5_start[];
803 extern initcall_t __initcall6_start[];
804 extern initcall_t __initcall7_start[];
805 extern initcall_t __initcall_end[];
806 
807 static initcall_t *initcall_levels[] __initdata = {
808         __initcall0_start,
809         __initcall1_start,
810         __initcall2_start,
811         __initcall3_start,
812         __initcall4_start,
813         __initcall5_start,
814         __initcall6_start,
815         __initcall7_start,
816         __initcall_end,
817 };
818 
819 /* Keep these in sync with initcalls in include/linux/init.h */
820 static char *initcall_level_names[] __initdata = {
821         "early",
822         "core",
823         "postcore",
824         "arch",
825         "subsys",
826         "fs",
827         "device",
828         "late",
829 };
830 
831 static void __init do_initcall_level(int level)
832 {
833         initcall_t *fn;
834 
835         strcpy(initcall_command_line, saved_command_line);
836         parse_args(initcall_level_names[level],
837                    initcall_command_line, __start___param,
838                    __stop___param - __start___param,
839                    level, level,
840                    NULL, &repair_env_string);
841 
842         for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
843                 do_one_initcall(*fn);
844 }
845 
846 static void __init do_initcalls(void)
847 {
848         int level;
849 
850         for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
851                 do_initcall_level(level);
852 }
853 
854 /*
855  * Ok, the machine is now initialized. None of the devices
856  * have been touched yet, but the CPU subsystem is up and
857  * running, and memory and process management works.
858  *
859  * Now we can finally start doing some real work..
860  */
861 static void __init do_basic_setup(void)
862 {
863         cpuset_init_smp();
864         shmem_init();
865         driver_init();
866         init_irq_proc();
867         do_ctors();
868         usermodehelper_enable();
869         do_initcalls();
870         random_int_secret_init();
871 }
872 
873 static void __init do_pre_smp_initcalls(void)
874 {
875         initcall_t *fn;
876 
877         for (fn = __initcall_start; fn < __initcall0_start; fn++)
878                 do_one_initcall(*fn);
879 }
880 
881 /*
882  * This function requests modules which should be loaded by default and is
883  * called twice right after initrd is mounted and right before init is
884  * exec'd.  If such modules are on either initrd or rootfs, they will be
885  * loaded before control is passed to userland.
886  */
887 void __init load_default_modules(void)
888 {
889         load_default_elevator_module();
890 }
891 
892 static int run_init_process(const char *init_filename)
893 {
894         argv_init[0] = init_filename;
895         return do_execve(getname_kernel(init_filename),
896                 (const char __user *const __user *)argv_init,
897                 (const char __user *const __user *)envp_init);
898 }
899 
900 static int try_to_run_init_process(const char *init_filename)
901 {
902         int ret;
903 
904         ret = run_init_process(init_filename);
905 
906         if (ret && ret != -ENOENT) {
907                 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
908                        init_filename, ret);
909         }
910 
911         return ret;
912 }
913 
914 static noinline void __init kernel_init_freeable(void);
915 
916 #ifdef CONFIG_DEBUG_RODATA
917 static bool rodata_enabled = true;
918 static int __init set_debug_rodata(char *str)
919 {
920         return strtobool(str, &rodata_enabled);
921 }
922 __setup("rodata=", set_debug_rodata);
923 
924 static void mark_readonly(void)
925 {
926         if (rodata_enabled)
927                 mark_rodata_ro();
928         else
929                 pr_info("Kernel memory protection disabled.\n");
930 }
931 #else
932 static inline void mark_readonly(void)
933 {
934         pr_warn("This architecture does not have kernel memory protection.\n");
935 }
936 #endif
937 
938 static int __ref kernel_init(void *unused)
939 {
940         int ret;
941 
942         kernel_init_freeable();
943         /* need to finish all async __init code before freeing the memory */
944         async_synchronize_full();
945         free_initmem();
946         mark_readonly();
947         system_state = SYSTEM_RUNNING;
948         numa_default_policy();
949 
950         flush_delayed_fput();
951 
952         rcu_end_inkernel_boot();
953 
954         if (ramdisk_execute_command) {
955                 ret = run_init_process(ramdisk_execute_command);
956                 if (!ret)
957                         return 0;
958                 pr_err("Failed to execute %s (error %d)\n",
959                        ramdisk_execute_command, ret);
960         }
961 
962         /*
963          * We try each of these until one succeeds.
964          *
965          * The Bourne shell can be used instead of init if we are
966          * trying to recover a really broken machine.
967          */
968         if (execute_command) {
969                 ret = run_init_process(execute_command);
970                 if (!ret)
971                         return 0;
972                 panic("Requested init %s failed (error %d).",
973                       execute_command, ret);
974         }
975         if (!try_to_run_init_process("/sbin/init") ||
976             !try_to_run_init_process("/etc/init") ||
977             !try_to_run_init_process("/bin/init") ||
978             !try_to_run_init_process("/bin/sh"))
979                 return 0;
980 
981         panic("No working init found.  Try passing init= option to kernel. "
982               "See Linux Documentation/init.txt for guidance.");
983 }
984 
985 static noinline void __init kernel_init_freeable(void)
986 {
987         /*
988          * Wait until kthreadd is all set-up.
989          */
990         wait_for_completion(&kthreadd_done);
991 
992         /* Now the scheduler is fully set up and can do blocking allocations */
993         gfp_allowed_mask = __GFP_BITS_MASK;
994 
995         /*
996          * init can allocate pages on any node
997          */
998         set_mems_allowed(node_states[N_MEMORY]);
999         /*
1000          * init can run on any cpu.
1001          */
1002         set_cpus_allowed_ptr(current, cpu_all_mask);
1003 
1004         cad_pid = task_pid(current);
1005 
1006         smp_prepare_cpus(setup_max_cpus);
1007 
1008         do_pre_smp_initcalls();
1009         lockup_detector_init();
1010 
1011         smp_init();
1012         sched_init_smp();
1013 
1014         page_alloc_init_late();
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 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us