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TOMOYO Linux Cross Reference
Linux/init/main.c

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  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/extable.h>
 16 #include <linux/module.h>
 17 #include <linux/proc_fs.h>
 18 #include <linux/binfmts.h>
 19 #include <linux/kernel.h>
 20 #include <linux/syscalls.h>
 21 #include <linux/stackprotector.h>
 22 #include <linux/string.h>
 23 #include <linux/ctype.h>
 24 #include <linux/delay.h>
 25 #include <linux/ioport.h>
 26 #include <linux/init.h>
 27 #include <linux/initrd.h>
 28 #include <linux/memblock.h>
 29 #include <linux/acpi.h>
 30 #include <linux/console.h>
 31 #include <linux/nmi.h>
 32 #include <linux/percpu.h>
 33 #include <linux/kmod.h>
 34 #include <linux/vmalloc.h>
 35 #include <linux/kernel_stat.h>
 36 #include <linux/start_kernel.h>
 37 #include <linux/security.h>
 38 #include <linux/smp.h>
 39 #include <linux/profile.h>
 40 #include <linux/rcupdate.h>
 41 #include <linux/moduleparam.h>
 42 #include <linux/kallsyms.h>
 43 #include <linux/writeback.h>
 44 #include <linux/cpu.h>
 45 #include <linux/cpuset.h>
 46 #include <linux/cgroup.h>
 47 #include <linux/efi.h>
 48 #include <linux/tick.h>
 49 #include <linux/sched/isolation.h>
 50 #include <linux/interrupt.h>
 51 #include <linux/taskstats_kern.h>
 52 #include <linux/delayacct.h>
 53 #include <linux/unistd.h>
 54 #include <linux/utsname.h>
 55 #include <linux/rmap.h>
 56 #include <linux/mempolicy.h>
 57 #include <linux/key.h>
 58 #include <linux/buffer_head.h>
 59 #include <linux/page_ext.h>
 60 #include <linux/debug_locks.h>
 61 #include <linux/debugobjects.h>
 62 #include <linux/lockdep.h>
 63 #include <linux/kmemleak.h>
 64 #include <linux/pid_namespace.h>
 65 #include <linux/device.h>
 66 #include <linux/kthread.h>
 67 #include <linux/sched.h>
 68 #include <linux/sched/init.h>
 69 #include <linux/signal.h>
 70 #include <linux/idr.h>
 71 #include <linux/kgdb.h>
 72 #include <linux/ftrace.h>
 73 #include <linux/async.h>
 74 #include <linux/sfi.h>
 75 #include <linux/shmem_fs.h>
 76 #include <linux/slab.h>
 77 #include <linux/perf_event.h>
 78 #include <linux/ptrace.h>
 79 #include <linux/pti.h>
 80 #include <linux/blkdev.h>
 81 #include <linux/elevator.h>
 82 #include <linux/sched/clock.h>
 83 #include <linux/sched/task.h>
 84 #include <linux/sched/task_stack.h>
 85 #include <linux/context_tracking.h>
 86 #include <linux/random.h>
 87 #include <linux/list.h>
 88 #include <linux/integrity.h>
 89 #include <linux/proc_ns.h>
 90 #include <linux/io.h>
 91 #include <linux/cache.h>
 92 #include <linux/rodata_test.h>
 93 #include <linux/jump_label.h>
 94 #include <linux/mem_encrypt.h>
 95 
 96 #include <asm/io.h>
 97 #include <asm/bugs.h>
 98 #include <asm/setup.h>
 99 #include <asm/sections.h>
100 #include <asm/cacheflush.h>
101 
102 #define CREATE_TRACE_POINTS
103 #include <trace/events/initcall.h>
104 
105 static int kernel_init(void *);
106 
107 extern void init_IRQ(void);
108 extern void radix_tree_init(void);
109 
110 /*
111  * Debug helper: via this flag we know that we are in 'early bootup code'
112  * where only the boot processor is running with IRQ disabled.  This means
113  * two things - IRQ must not be enabled before the flag is cleared and some
114  * operations which are not allowed with IRQ disabled are allowed while the
115  * flag is set.
116  */
117 bool early_boot_irqs_disabled __read_mostly;
118 
119 enum system_states system_state __read_mostly;
120 EXPORT_SYMBOL(system_state);
121 
122 /*
123  * Boot command-line arguments
124  */
125 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
126 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
127 
128 extern void time_init(void);
129 /* Default late time init is NULL. archs can override this later. */
130 void (*__initdata late_time_init)(void);
131 
132 /* Untouched command line saved by arch-specific code. */
133 char __initdata boot_command_line[COMMAND_LINE_SIZE];
134 /* Untouched saved command line (eg. for /proc) */
135 char *saved_command_line;
136 /* Command line for parameter parsing */
137 static char *static_command_line;
138 /* Command line for per-initcall parameter parsing */
139 static char *initcall_command_line;
140 
141 static char *execute_command;
142 static char *ramdisk_execute_command;
143 
144 /*
145  * Used to generate warnings if static_key manipulation functions are used
146  * before jump_label_init is called.
147  */
148 bool static_key_initialized __read_mostly;
149 EXPORT_SYMBOL_GPL(static_key_initialized);
150 
151 /*
152  * If set, this is an indication to the drivers that reset the underlying
153  * device before going ahead with the initialization otherwise driver might
154  * rely on the BIOS and skip the reset operation.
155  *
156  * This is useful if kernel is booting in an unreliable environment.
157  * For ex. kdump situation where previous kernel has crashed, BIOS has been
158  * skipped and devices will be in unknown state.
159  */
160 unsigned int reset_devices;
161 EXPORT_SYMBOL(reset_devices);
162 
163 static int __init set_reset_devices(char *str)
164 {
165         reset_devices = 1;
166         return 1;
167 }
168 
169 __setup("reset_devices", set_reset_devices);
170 
171 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
172 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
173 static const char *panic_later, *panic_param;
174 
175 extern const struct obs_kernel_param __setup_start[], __setup_end[];
176 
177 static bool __init obsolete_checksetup(char *line)
178 {
179         const struct obs_kernel_param *p;
180         bool had_early_param = false;
181 
182         p = __setup_start;
183         do {
184                 int n = strlen(p->str);
185                 if (parameqn(line, p->str, n)) {
186                         if (p->early) {
187                                 /* Already done in parse_early_param?
188                                  * (Needs exact match on param part).
189                                  * Keep iterating, as we can have early
190                                  * params and __setups of same names 8( */
191                                 if (line[n] == '\0' || line[n] == '=')
192                                         had_early_param = true;
193                         } else if (!p->setup_func) {
194                                 pr_warn("Parameter %s is obsolete, ignored\n",
195                                         p->str);
196                                 return true;
197                         } else if (p->setup_func(line + n))
198                                 return true;
199                 }
200                 p++;
201         } while (p < __setup_end);
202 
203         return had_early_param;
204 }
205 
206 /*
207  * This should be approx 2 Bo*oMips to start (note initial shift), and will
208  * still work even if initially too large, it will just take slightly longer
209  */
210 unsigned long loops_per_jiffy = (1<<12);
211 EXPORT_SYMBOL(loops_per_jiffy);
212 
213 static int __init debug_kernel(char *str)
214 {
215         console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
216         return 0;
217 }
218 
219 static int __init quiet_kernel(char *str)
220 {
221         console_loglevel = CONSOLE_LOGLEVEL_QUIET;
222         return 0;
223 }
224 
225 early_param("debug", debug_kernel);
226 early_param("quiet", quiet_kernel);
227 
228 static int __init loglevel(char *str)
229 {
230         int newlevel;
231 
232         /*
233          * Only update loglevel value when a correct setting was passed,
234          * to prevent blind crashes (when loglevel being set to 0) that
235          * are quite hard to debug
236          */
237         if (get_option(&str, &newlevel)) {
238                 console_loglevel = newlevel;
239                 return 0;
240         }
241 
242         return -EINVAL;
243 }
244 
245 early_param("loglevel", loglevel);
246 
247 /* Change NUL term back to "=", to make "param" the whole string. */
248 static int __init repair_env_string(char *param, char *val,
249                                     const char *unused, void *arg)
250 {
251         if (val) {
252                 /* param=val or param="val"? */
253                 if (val == param+strlen(param)+1)
254                         val[-1] = '=';
255                 else if (val == param+strlen(param)+2) {
256                         val[-2] = '=';
257                         memmove(val-1, val, strlen(val)+1);
258                         val--;
259                 } else
260                         BUG();
261         }
262         return 0;
263 }
264 
265 /* Anything after -- gets handed straight to init. */
266 static int __init set_init_arg(char *param, char *val,
267                                const char *unused, void *arg)
268 {
269         unsigned int i;
270 
271         if (panic_later)
272                 return 0;
273 
274         repair_env_string(param, val, unused, NULL);
275 
276         for (i = 0; argv_init[i]; i++) {
277                 if (i == MAX_INIT_ARGS) {
278                         panic_later = "init";
279                         panic_param = param;
280                         return 0;
281                 }
282         }
283         argv_init[i] = param;
284         return 0;
285 }
286 
287 /*
288  * Unknown boot options get handed to init, unless they look like
289  * unused parameters (modprobe will find them in /proc/cmdline).
290  */
291 static int __init unknown_bootoption(char *param, char *val,
292                                      const char *unused, void *arg)
293 {
294         repair_env_string(param, val, unused, NULL);
295 
296         /* Handle obsolete-style parameters */
297         if (obsolete_checksetup(param))
298                 return 0;
299 
300         /* Unused module parameter. */
301         if (strchr(param, '.') && (!val || strchr(param, '.') < val))
302                 return 0;
303 
304         if (panic_later)
305                 return 0;
306 
307         if (val) {
308                 /* Environment option */
309                 unsigned int i;
310                 for (i = 0; envp_init[i]; i++) {
311                         if (i == MAX_INIT_ENVS) {
312                                 panic_later = "env";
313                                 panic_param = param;
314                         }
315                         if (!strncmp(param, envp_init[i], val - param))
316                                 break;
317                 }
318                 envp_init[i] = param;
319         } else {
320                 /* Command line option */
321                 unsigned int i;
322                 for (i = 0; argv_init[i]; i++) {
323                         if (i == MAX_INIT_ARGS) {
324                                 panic_later = "init";
325                                 panic_param = param;
326                         }
327                 }
328                 argv_init[i] = param;
329         }
330         return 0;
331 }
332 
333 static int __init init_setup(char *str)
334 {
335         unsigned int i;
336 
337         execute_command = str;
338         /*
339          * In case LILO is going to boot us with default command line,
340          * it prepends "auto" before the whole cmdline which makes
341          * the shell think it should execute a script with such name.
342          * So we ignore all arguments entered _before_ init=... [MJ]
343          */
344         for (i = 1; i < MAX_INIT_ARGS; i++)
345                 argv_init[i] = NULL;
346         return 1;
347 }
348 __setup("init=", init_setup);
349 
350 static int __init rdinit_setup(char *str)
351 {
352         unsigned int i;
353 
354         ramdisk_execute_command = str;
355         /* See "auto" comment in init_setup */
356         for (i = 1; i < MAX_INIT_ARGS; i++)
357                 argv_init[i] = NULL;
358         return 1;
359 }
360 __setup("rdinit=", rdinit_setup);
361 
362 #ifndef CONFIG_SMP
363 static const unsigned int setup_max_cpus = NR_CPUS;
364 static inline void setup_nr_cpu_ids(void) { }
365 static inline void smp_prepare_cpus(unsigned int maxcpus) { }
366 #endif
367 
368 /*
369  * We need to store the untouched command line for future reference.
370  * We also need to store the touched command line since the parameter
371  * parsing is performed in place, and we should allow a component to
372  * store reference of name/value for future reference.
373  */
374 static void __init setup_command_line(char *command_line)
375 {
376         size_t len = strlen(boot_command_line) + 1;
377 
378         saved_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
379         if (!saved_command_line)
380                 panic("%s: Failed to allocate %zu bytes\n", __func__, len);
381 
382         initcall_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
383         if (!initcall_command_line)
384                 panic("%s: Failed to allocate %zu bytes\n", __func__, len);
385 
386         static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
387         if (!static_command_line)
388                 panic("%s: Failed to allocate %zu bytes\n", __func__, len);
389 
390         strcpy(saved_command_line, boot_command_line);
391         strcpy(static_command_line, command_line);
392 }
393 
394 /*
395  * We need to finalize in a non-__init function or else race conditions
396  * between the root thread and the init thread may cause start_kernel to
397  * be reaped by free_initmem before the root thread has proceeded to
398  * cpu_idle.
399  *
400  * gcc-3.4 accidentally inlines this function, so use noinline.
401  */
402 
403 static __initdata DECLARE_COMPLETION(kthreadd_done);
404 
405 noinline void __ref rest_init(void)
406 {
407         struct task_struct *tsk;
408         int pid;
409 
410         rcu_scheduler_starting();
411         /*
412          * We need to spawn init first so that it obtains pid 1, however
413          * the init task will end up wanting to create kthreads, which, if
414          * we schedule it before we create kthreadd, will OOPS.
415          */
416         pid = kernel_thread(kernel_init, NULL, CLONE_FS);
417         /*
418          * Pin init on the boot CPU. Task migration is not properly working
419          * until sched_init_smp() has been run. It will set the allowed
420          * CPUs for init to the non isolated CPUs.
421          */
422         rcu_read_lock();
423         tsk = find_task_by_pid_ns(pid, &init_pid_ns);
424         set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
425         rcu_read_unlock();
426 
427         numa_default_policy();
428         pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
429         rcu_read_lock();
430         kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
431         rcu_read_unlock();
432 
433         /*
434          * Enable might_sleep() and smp_processor_id() checks.
435          * They cannot be enabled earlier because with CONFIG_PREEMPT=y
436          * kernel_thread() would trigger might_sleep() splats. With
437          * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
438          * already, but it's stuck on the kthreadd_done completion.
439          */
440         system_state = SYSTEM_SCHEDULING;
441 
442         complete(&kthreadd_done);
443 
444         /*
445          * The boot idle thread must execute schedule()
446          * at least once to get things moving:
447          */
448         schedule_preempt_disabled();
449         /* Call into cpu_idle with preempt disabled */
450         cpu_startup_entry(CPUHP_ONLINE);
451 }
452 
453 /* Check for early params. */
454 static int __init do_early_param(char *param, char *val,
455                                  const char *unused, void *arg)
456 {
457         const struct obs_kernel_param *p;
458 
459         for (p = __setup_start; p < __setup_end; p++) {
460                 if ((p->early && parameq(param, p->str)) ||
461                     (strcmp(param, "console") == 0 &&
462                      strcmp(p->str, "earlycon") == 0)
463                 ) {
464                         if (p->setup_func(val) != 0)
465                                 pr_warn("Malformed early option '%s'\n", param);
466                 }
467         }
468         /* We accept everything at this stage. */
469         return 0;
470 }
471 
472 void __init parse_early_options(char *cmdline)
473 {
474         parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
475                    do_early_param);
476 }
477 
478 /* Arch code calls this early on, or if not, just before other parsing. */
479 void __init parse_early_param(void)
480 {
481         static int done __initdata;
482         static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
483 
484         if (done)
485                 return;
486 
487         /* All fall through to do_early_param. */
488         strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
489         parse_early_options(tmp_cmdline);
490         done = 1;
491 }
492 
493 void __init __weak arch_post_acpi_subsys_init(void) { }
494 
495 void __init __weak smp_setup_processor_id(void)
496 {
497 }
498 
499 # if THREAD_SIZE >= PAGE_SIZE
500 void __init __weak thread_stack_cache_init(void)
501 {
502 }
503 #endif
504 
505 void __init __weak mem_encrypt_init(void) { }
506 
507 bool initcall_debug;
508 core_param(initcall_debug, initcall_debug, bool, 0644);
509 
510 #ifdef TRACEPOINTS_ENABLED
511 static void __init initcall_debug_enable(void);
512 #else
513 static inline void initcall_debug_enable(void)
514 {
515 }
516 #endif
517 
518 /*
519  * Set up kernel memory allocators
520  */
521 static void __init mm_init(void)
522 {
523         /*
524          * page_ext requires contiguous pages,
525          * bigger than MAX_ORDER unless SPARSEMEM.
526          */
527         page_ext_init_flatmem();
528         mem_init();
529         kmem_cache_init();
530         pgtable_init();
531         debug_objects_mem_init();
532         vmalloc_init();
533         ioremap_huge_init();
534         /* Should be run before the first non-init thread is created */
535         init_espfix_bsp();
536         /* Should be run after espfix64 is set up. */
537         pti_init();
538 }
539 
540 void __init __weak arch_call_rest_init(void)
541 {
542         rest_init();
543 }
544 
545 asmlinkage __visible void __init start_kernel(void)
546 {
547         char *command_line;
548         char *after_dashes;
549 
550         set_task_stack_end_magic(&init_task);
551         smp_setup_processor_id();
552         debug_objects_early_init();
553 
554         cgroup_init_early();
555 
556         local_irq_disable();
557         early_boot_irqs_disabled = true;
558 
559         /*
560          * Interrupts are still disabled. Do necessary setups, then
561          * enable them.
562          */
563         boot_cpu_init();
564         page_address_init();
565         pr_notice("%s", linux_banner);
566         setup_arch(&command_line);
567         /*
568          * Set up the the initial canary and entropy after arch
569          * and after adding latent and command line entropy.
570          */
571         add_latent_entropy();
572         add_device_randomness(command_line, strlen(command_line));
573         boot_init_stack_canary();
574         mm_init_cpumask(&init_mm);
575         setup_command_line(command_line);
576         setup_nr_cpu_ids();
577         setup_per_cpu_areas();
578         smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
579         boot_cpu_hotplug_init();
580 
581         build_all_zonelists(NULL);
582         page_alloc_init();
583 
584         pr_notice("Kernel command line: %s\n", boot_command_line);
585         parse_early_param();
586         after_dashes = parse_args("Booting kernel",
587                                   static_command_line, __start___param,
588                                   __stop___param - __start___param,
589                                   -1, -1, NULL, &unknown_bootoption);
590         if (!IS_ERR_OR_NULL(after_dashes))
591                 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
592                            NULL, set_init_arg);
593 
594         jump_label_init();
595 
596         /*
597          * These use large bootmem allocations and must precede
598          * kmem_cache_init()
599          */
600         setup_log_buf(0);
601         vfs_caches_init_early();
602         sort_main_extable();
603         trap_init();
604         mm_init();
605 
606         ftrace_init();
607 
608         /* trace_printk can be enabled here */
609         early_trace_init();
610 
611         /*
612          * Set up the scheduler prior starting any interrupts (such as the
613          * timer interrupt). Full topology setup happens at smp_init()
614          * time - but meanwhile we still have a functioning scheduler.
615          */
616         sched_init();
617         /*
618          * Disable preemption - early bootup scheduling is extremely
619          * fragile until we cpu_idle() for the first time.
620          */
621         preempt_disable();
622         if (WARN(!irqs_disabled(),
623                  "Interrupts were enabled *very* early, fixing it\n"))
624                 local_irq_disable();
625         radix_tree_init();
626 
627         /*
628          * Set up housekeeping before setting up workqueues to allow the unbound
629          * workqueue to take non-housekeeping into account.
630          */
631         housekeeping_init();
632 
633         /*
634          * Allow workqueue creation and work item queueing/cancelling
635          * early.  Work item execution depends on kthreads and starts after
636          * workqueue_init().
637          */
638         workqueue_init_early();
639 
640         rcu_init();
641 
642         /* Trace events are available after this */
643         trace_init();
644 
645         if (initcall_debug)
646                 initcall_debug_enable();
647 
648         context_tracking_init();
649         /* init some links before init_ISA_irqs() */
650         early_irq_init();
651         init_IRQ();
652         tick_init();
653         rcu_init_nohz();
654         init_timers();
655         hrtimers_init();
656         softirq_init();
657         timekeeping_init();
658         time_init();
659         printk_safe_init();
660         perf_event_init();
661         profile_init();
662         call_function_init();
663         WARN(!irqs_disabled(), "Interrupts were enabled early\n");
664 
665         early_boot_irqs_disabled = false;
666         local_irq_enable();
667 
668         kmem_cache_init_late();
669 
670         /*
671          * HACK ALERT! This is early. We're enabling the console before
672          * we've done PCI setups etc, and console_init() must be aware of
673          * this. But we do want output early, in case something goes wrong.
674          */
675         console_init();
676         if (panic_later)
677                 panic("Too many boot %s vars at `%s'", panic_later,
678                       panic_param);
679 
680         lockdep_init();
681 
682         /*
683          * Need to run this when irqs are enabled, because it wants
684          * to self-test [hard/soft]-irqs on/off lock inversion bugs
685          * too:
686          */
687         locking_selftest();
688 
689         /*
690          * This needs to be called before any devices perform DMA
691          * operations that might use the SWIOTLB bounce buffers. It will
692          * mark the bounce buffers as decrypted so that their usage will
693          * not cause "plain-text" data to be decrypted when accessed.
694          */
695         mem_encrypt_init();
696 
697 #ifdef CONFIG_BLK_DEV_INITRD
698         if (initrd_start && !initrd_below_start_ok &&
699             page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
700                 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
701                     page_to_pfn(virt_to_page((void *)initrd_start)),
702                     min_low_pfn);
703                 initrd_start = 0;
704         }
705 #endif
706         kmemleak_init();
707         setup_per_cpu_pageset();
708         numa_policy_init();
709         acpi_early_init();
710         if (late_time_init)
711                 late_time_init();
712         sched_clock_init();
713         calibrate_delay();
714         pid_idr_init();
715         anon_vma_init();
716 #ifdef CONFIG_X86
717         if (efi_enabled(EFI_RUNTIME_SERVICES))
718                 efi_enter_virtual_mode();
719 #endif
720         thread_stack_cache_init();
721         cred_init();
722         fork_init();
723         proc_caches_init();
724         uts_ns_init();
725         buffer_init();
726         key_init();
727         security_init();
728         dbg_late_init();
729         vfs_caches_init();
730         pagecache_init();
731         signals_init();
732         seq_file_init();
733         proc_root_init();
734         nsfs_init();
735         cpuset_init();
736         cgroup_init();
737         taskstats_init_early();
738         delayacct_init();
739 
740         check_bugs();
741 
742         acpi_subsystem_init();
743         arch_post_acpi_subsys_init();
744         sfi_init_late();
745 
746         /* Do the rest non-__init'ed, we're now alive */
747         arch_call_rest_init();
748 }
749 
750 /* Call all constructor functions linked into the kernel. */
751 static void __init do_ctors(void)
752 {
753 #ifdef CONFIG_CONSTRUCTORS
754         ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
755 
756         for (; fn < (ctor_fn_t *) __ctors_end; fn++)
757                 (*fn)();
758 #endif
759 }
760 
761 #ifdef CONFIG_KALLSYMS
762 struct blacklist_entry {
763         struct list_head next;
764         char *buf;
765 };
766 
767 static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
768 
769 static int __init initcall_blacklist(char *str)
770 {
771         char *str_entry;
772         struct blacklist_entry *entry;
773 
774         /* str argument is a comma-separated list of functions */
775         do {
776                 str_entry = strsep(&str, ",");
777                 if (str_entry) {
778                         pr_debug("blacklisting initcall %s\n", str_entry);
779                         entry = memblock_alloc(sizeof(*entry),
780                                                SMP_CACHE_BYTES);
781                         if (!entry)
782                                 panic("%s: Failed to allocate %zu bytes\n",
783                                       __func__, sizeof(*entry));
784                         entry->buf = memblock_alloc(strlen(str_entry) + 1,
785                                                     SMP_CACHE_BYTES);
786                         if (!entry->buf)
787                                 panic("%s: Failed to allocate %zu bytes\n",
788                                       __func__, strlen(str_entry) + 1);
789                         strcpy(entry->buf, str_entry);
790                         list_add(&entry->next, &blacklisted_initcalls);
791                 }
792         } while (str_entry);
793 
794         return 0;
795 }
796 
797 static bool __init_or_module initcall_blacklisted(initcall_t fn)
798 {
799         struct blacklist_entry *entry;
800         char fn_name[KSYM_SYMBOL_LEN];
801         unsigned long addr;
802 
803         if (list_empty(&blacklisted_initcalls))
804                 return false;
805 
806         addr = (unsigned long) dereference_function_descriptor(fn);
807         sprint_symbol_no_offset(fn_name, addr);
808 
809         /*
810          * fn will be "function_name [module_name]" where [module_name] is not
811          * displayed for built-in init functions.  Strip off the [module_name].
812          */
813         strreplace(fn_name, ' ', '\0');
814 
815         list_for_each_entry(entry, &blacklisted_initcalls, next) {
816                 if (!strcmp(fn_name, entry->buf)) {
817                         pr_debug("initcall %s blacklisted\n", fn_name);
818                         return true;
819                 }
820         }
821 
822         return false;
823 }
824 #else
825 static int __init initcall_blacklist(char *str)
826 {
827         pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
828         return 0;
829 }
830 
831 static bool __init_or_module initcall_blacklisted(initcall_t fn)
832 {
833         return false;
834 }
835 #endif
836 __setup("initcall_blacklist=", initcall_blacklist);
837 
838 static __init_or_module void
839 trace_initcall_start_cb(void *data, initcall_t fn)
840 {
841         ktime_t *calltime = (ktime_t *)data;
842 
843         printk(KERN_DEBUG "calling  %pF @ %i\n", fn, task_pid_nr(current));
844         *calltime = ktime_get();
845 }
846 
847 static __init_or_module void
848 trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
849 {
850         ktime_t *calltime = (ktime_t *)data;
851         ktime_t delta, rettime;
852         unsigned long long duration;
853 
854         rettime = ktime_get();
855         delta = ktime_sub(rettime, *calltime);
856         duration = (unsigned long long) ktime_to_ns(delta) >> 10;
857         printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n",
858                  fn, ret, duration);
859 }
860 
861 static ktime_t initcall_calltime;
862 
863 #ifdef TRACEPOINTS_ENABLED
864 static void __init initcall_debug_enable(void)
865 {
866         int ret;
867 
868         ret = register_trace_initcall_start(trace_initcall_start_cb,
869                                             &initcall_calltime);
870         ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
871                                               &initcall_calltime);
872         WARN(ret, "Failed to register initcall tracepoints\n");
873 }
874 # define do_trace_initcall_start        trace_initcall_start
875 # define do_trace_initcall_finish       trace_initcall_finish
876 #else
877 static inline void do_trace_initcall_start(initcall_t fn)
878 {
879         if (!initcall_debug)
880                 return;
881         trace_initcall_start_cb(&initcall_calltime, fn);
882 }
883 static inline void do_trace_initcall_finish(initcall_t fn, int ret)
884 {
885         if (!initcall_debug)
886                 return;
887         trace_initcall_finish_cb(&initcall_calltime, fn, ret);
888 }
889 #endif /* !TRACEPOINTS_ENABLED */
890 
891 int __init_or_module do_one_initcall(initcall_t fn)
892 {
893         int count = preempt_count();
894         char msgbuf[64];
895         int ret;
896 
897         if (initcall_blacklisted(fn))
898                 return -EPERM;
899 
900         do_trace_initcall_start(fn);
901         ret = fn();
902         do_trace_initcall_finish(fn, ret);
903 
904         msgbuf[0] = 0;
905 
906         if (preempt_count() != count) {
907                 sprintf(msgbuf, "preemption imbalance ");
908                 preempt_count_set(count);
909         }
910         if (irqs_disabled()) {
911                 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
912                 local_irq_enable();
913         }
914         WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
915 
916         add_latent_entropy();
917         return ret;
918 }
919 
920 
921 extern initcall_entry_t __initcall_start[];
922 extern initcall_entry_t __initcall0_start[];
923 extern initcall_entry_t __initcall1_start[];
924 extern initcall_entry_t __initcall2_start[];
925 extern initcall_entry_t __initcall3_start[];
926 extern initcall_entry_t __initcall4_start[];
927 extern initcall_entry_t __initcall5_start[];
928 extern initcall_entry_t __initcall6_start[];
929 extern initcall_entry_t __initcall7_start[];
930 extern initcall_entry_t __initcall_end[];
931 
932 static initcall_entry_t *initcall_levels[] __initdata = {
933         __initcall0_start,
934         __initcall1_start,
935         __initcall2_start,
936         __initcall3_start,
937         __initcall4_start,
938         __initcall5_start,
939         __initcall6_start,
940         __initcall7_start,
941         __initcall_end,
942 };
943 
944 /* Keep these in sync with initcalls in include/linux/init.h */
945 static const char *initcall_level_names[] __initdata = {
946         "pure",
947         "core",
948         "postcore",
949         "arch",
950         "subsys",
951         "fs",
952         "device",
953         "late",
954 };
955 
956 static void __init do_initcall_level(int level)
957 {
958         initcall_entry_t *fn;
959 
960         strcpy(initcall_command_line, saved_command_line);
961         parse_args(initcall_level_names[level],
962                    initcall_command_line, __start___param,
963                    __stop___param - __start___param,
964                    level, level,
965                    NULL, &repair_env_string);
966 
967         trace_initcall_level(initcall_level_names[level]);
968         for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
969                 do_one_initcall(initcall_from_entry(fn));
970 }
971 
972 static void __init do_initcalls(void)
973 {
974         int level;
975 
976         for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
977                 do_initcall_level(level);
978 }
979 
980 /*
981  * Ok, the machine is now initialized. None of the devices
982  * have been touched yet, but the CPU subsystem is up and
983  * running, and memory and process management works.
984  *
985  * Now we can finally start doing some real work..
986  */
987 static void __init do_basic_setup(void)
988 {
989         cpuset_init_smp();
990         shmem_init();
991         driver_init();
992         init_irq_proc();
993         do_ctors();
994         usermodehelper_enable();
995         do_initcalls();
996 }
997 
998 static void __init do_pre_smp_initcalls(void)
999 {
1000         initcall_entry_t *fn;
1001 
1002         trace_initcall_level("early");
1003         for (fn = __initcall_start; fn < __initcall0_start; fn++)
1004                 do_one_initcall(initcall_from_entry(fn));
1005 }
1006 
1007 static int run_init_process(const char *init_filename)
1008 {
1009         argv_init[0] = init_filename;
1010         pr_info("Run %s as init process\n", init_filename);
1011         return do_execve(getname_kernel(init_filename),
1012                 (const char __user *const __user *)argv_init,
1013                 (const char __user *const __user *)envp_init);
1014 }
1015 
1016 static int try_to_run_init_process(const char *init_filename)
1017 {
1018         int ret;
1019 
1020         ret = run_init_process(init_filename);
1021 
1022         if (ret && ret != -ENOENT) {
1023                 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1024                        init_filename, ret);
1025         }
1026 
1027         return ret;
1028 }
1029 
1030 static noinline void __init kernel_init_freeable(void);
1031 
1032 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1033 bool rodata_enabled __ro_after_init = true;
1034 static int __init set_debug_rodata(char *str)
1035 {
1036         return strtobool(str, &rodata_enabled);
1037 }
1038 __setup("rodata=", set_debug_rodata);
1039 #endif
1040 
1041 #ifdef CONFIG_STRICT_KERNEL_RWX
1042 static void mark_readonly(void)
1043 {
1044         if (rodata_enabled) {
1045                 /*
1046                  * load_module() results in W+X mappings, which are cleaned
1047                  * up with call_rcu().  Let's make sure that queued work is
1048                  * flushed so that we don't hit false positives looking for
1049                  * insecure pages which are W+X.
1050                  */
1051                 rcu_barrier();
1052                 mark_rodata_ro();
1053                 rodata_test();
1054         } else
1055                 pr_info("Kernel memory protection disabled.\n");
1056 }
1057 #else
1058 static inline void mark_readonly(void)
1059 {
1060         pr_warn("This architecture does not have kernel memory protection.\n");
1061 }
1062 #endif
1063 
1064 static int __ref kernel_init(void *unused)
1065 {
1066         int ret;
1067 
1068         kernel_init_freeable();
1069         /* need to finish all async __init code before freeing the memory */
1070         async_synchronize_full();
1071         ftrace_free_init_mem();
1072         free_initmem();
1073         mark_readonly();
1074 
1075         /*
1076          * Kernel mappings are now finalized - update the userspace page-table
1077          * to finalize PTI.
1078          */
1079         pti_finalize();
1080 
1081         system_state = SYSTEM_RUNNING;
1082         numa_default_policy();
1083 
1084         rcu_end_inkernel_boot();
1085 
1086         if (ramdisk_execute_command) {
1087                 ret = run_init_process(ramdisk_execute_command);
1088                 if (!ret)
1089                         return 0;
1090                 pr_err("Failed to execute %s (error %d)\n",
1091                        ramdisk_execute_command, ret);
1092         }
1093 
1094         /*
1095          * We try each of these until one succeeds.
1096          *
1097          * The Bourne shell can be used instead of init if we are
1098          * trying to recover a really broken machine.
1099          */
1100         if (execute_command) {
1101                 ret = run_init_process(execute_command);
1102                 if (!ret)
1103                         return 0;
1104                 panic("Requested init %s failed (error %d).",
1105                       execute_command, ret);
1106         }
1107         if (!try_to_run_init_process("/sbin/init") ||
1108             !try_to_run_init_process("/etc/init") ||
1109             !try_to_run_init_process("/bin/init") ||
1110             !try_to_run_init_process("/bin/sh"))
1111                 return 0;
1112 
1113         panic("No working init found.  Try passing init= option to kernel. "
1114               "See Linux Documentation/admin-guide/init.rst for guidance.");
1115 }
1116 
1117 static noinline void __init kernel_init_freeable(void)
1118 {
1119         /*
1120          * Wait until kthreadd is all set-up.
1121          */
1122         wait_for_completion(&kthreadd_done);
1123 
1124         /* Now the scheduler is fully set up and can do blocking allocations */
1125         gfp_allowed_mask = __GFP_BITS_MASK;
1126 
1127         /*
1128          * init can allocate pages on any node
1129          */
1130         set_mems_allowed(node_states[N_MEMORY]);
1131 
1132         cad_pid = task_pid(current);
1133 
1134         smp_prepare_cpus(setup_max_cpus);
1135 
1136         workqueue_init();
1137 
1138         init_mm_internals();
1139 
1140         do_pre_smp_initcalls();
1141         lockup_detector_init();
1142 
1143         smp_init();
1144         sched_init_smp();
1145 
1146         page_alloc_init_late();
1147         /* Initialize page ext after all struct pages are initialized. */
1148         page_ext_init();
1149 
1150         do_basic_setup();
1151 
1152         /* Open the /dev/console on the rootfs, this should never fail */
1153         if (ksys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
1154                 pr_err("Warning: unable to open an initial console.\n");
1155 
1156         (void) ksys_dup(0);
1157         (void) ksys_dup(0);
1158         /*
1159          * check if there is an early userspace init.  If yes, let it do all
1160          * the work
1161          */
1162 
1163         if (!ramdisk_execute_command)
1164                 ramdisk_execute_command = "/init";
1165 
1166         if (ksys_access((const char __user *)
1167                         ramdisk_execute_command, 0) != 0) {
1168                 ramdisk_execute_command = NULL;
1169                 prepare_namespace();
1170         }
1171 
1172         /*
1173          * Ok, we have completed the initial bootup, and
1174          * we're essentially up and running. Get rid of the
1175          * initmem segments and start the user-mode stuff..
1176          *
1177          * rootfs is available now, try loading the public keys
1178          * and default modules
1179          */
1180 
1181         integrity_load_keys();
1182 }
1183 

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