4 * Copyright (C) 1991, 1992 Linus Torvalds
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>
12 #define DEBUG /* Enable initcall_debug */
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/bootmem.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>
91 #include <linux/cache.h>
92 #include <linux/rodata_test.h>
93 #include <linux/jump_label.h>
94 #include <linux/mem_encrypt.h>
98 #include <asm/setup.h>
99 #include <asm/sections.h>
100 #include <asm/cacheflush.h>
102 #define CREATE_TRACE_POINTS
103 #include <trace/events/initcall.h>
105 static int kernel_init(void *);
107 extern void init_IRQ(void);
108 extern void radix_tree_init(void);
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
117 bool early_boot_irqs_disabled __read_mostly;
119 enum system_states system_state __read_mostly;
120 EXPORT_SYMBOL(system_state);
123 * Boot command-line arguments
125 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
126 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
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);
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;
141 static char *execute_command;
142 static char *ramdisk_execute_command;
145 * Used to generate warnings if static_key manipulation functions are used
146 * before jump_label_init is called.
148 bool static_key_initialized __read_mostly;
149 EXPORT_SYMBOL_GPL(static_key_initialized);
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.
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.
160 unsigned int reset_devices;
161 EXPORT_SYMBOL(reset_devices);
163 static int __init set_reset_devices(char *str)
169 __setup("reset_devices", set_reset_devices);
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;
175 extern const struct obs_kernel_param __setup_start[], __setup_end[];
177 static bool __init obsolete_checksetup(char *line)
179 const struct obs_kernel_param *p;
180 bool had_early_param = false;
184 int n = strlen(p->str);
185 if (parameqn(line, p->str, n)) {
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",
197 } else if (p->setup_func(line + n))
201 } while (p < __setup_end);
203 return had_early_param;
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
210 unsigned long loops_per_jiffy = (1<<12);
211 EXPORT_SYMBOL(loops_per_jiffy);
213 static int __init debug_kernel(char *str)
215 console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
219 static int __init quiet_kernel(char *str)
221 console_loglevel = CONSOLE_LOGLEVEL_QUIET;
225 early_param("debug", debug_kernel);
226 early_param("quiet", quiet_kernel);
228 static int __init loglevel(char *str)
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
237 if (get_option(&str, &newlevel)) {
238 console_loglevel = newlevel;
245 early_param("loglevel", loglevel);
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)
252 /* param=val or param="val"? */
253 if (val == param+strlen(param)+1)
255 else if (val == param+strlen(param)+2) {
257 memmove(val-1, val, strlen(val)+1);
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)
274 repair_env_string(param, val, unused, NULL);
276 for (i = 0; argv_init[i]; i++) {
277 if (i == MAX_INIT_ARGS) {
278 panic_later = "init";
283 argv_init[i] = param;
288 * Unknown boot options get handed to init, unless they look like
289 * unused parameters (modprobe will find them in /proc/cmdline).
291 static int __init unknown_bootoption(char *param, char *val,
292 const char *unused, void *arg)
294 repair_env_string(param, val, unused, NULL);
296 /* Handle obsolete-style parameters */
297 if (obsolete_checksetup(param))
300 /* Unused module parameter. */
301 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
308 /* Environment option */
310 for (i = 0; envp_init[i]; i++) {
311 if (i == MAX_INIT_ENVS) {
315 if (!strncmp(param, envp_init[i], val - param))
318 envp_init[i] = param;
320 /* Command line option */
322 for (i = 0; argv_init[i]; i++) {
323 if (i == MAX_INIT_ARGS) {
324 panic_later = "init";
328 argv_init[i] = param;
333 static int __init init_setup(char *str)
337 execute_command = str;
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]
344 for (i = 1; i < MAX_INIT_ARGS; i++)
348 __setup("init=", init_setup);
350 static int __init rdinit_setup(char *str)
354 ramdisk_execute_command = str;
355 /* See "auto" comment in init_setup */
356 for (i = 1; i < MAX_INIT_ARGS; i++)
360 __setup("rdinit=", rdinit_setup);
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) { }
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.
374 static void __init setup_command_line(char *command_line)
377 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
378 initcall_command_line =
379 memblock_virt_alloc(strlen(boot_command_line) + 1, 0);
380 static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0);
381 strcpy(saved_command_line, boot_command_line);
382 strcpy(static_command_line, command_line);
386 * We need to finalize in a non-__init function or else race conditions
387 * between the root thread and the init thread may cause start_kernel to
388 * be reaped by free_initmem before the root thread has proceeded to
391 * gcc-3.4 accidentally inlines this function, so use noinline.
394 static __initdata DECLARE_COMPLETION(kthreadd_done);
396 static noinline void __ref rest_init(void)
398 struct task_struct *tsk;
401 rcu_scheduler_starting();
403 * We need to spawn init first so that it obtains pid 1, however
404 * the init task will end up wanting to create kthreads, which, if
405 * we schedule it before we create kthreadd, will OOPS.
407 pid = kernel_thread(kernel_init, NULL, CLONE_FS);
409 * Pin init on the boot CPU. Task migration is not properly working
410 * until sched_init_smp() has been run. It will set the allowed
411 * CPUs for init to the non isolated CPUs.
414 tsk = find_task_by_pid_ns(pid, &init_pid_ns);
415 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
418 numa_default_policy();
419 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
421 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
425 * Enable might_sleep() and smp_processor_id() checks.
426 * They cannot be enabled earlier because with CONFIG_PREEMPT=y
427 * kernel_thread() would trigger might_sleep() splats. With
428 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
429 * already, but it's stuck on the kthreadd_done completion.
431 system_state = SYSTEM_SCHEDULING;
433 complete(&kthreadd_done);
436 * The boot idle thread must execute schedule()
437 * at least once to get things moving:
439 schedule_preempt_disabled();
440 /* Call into cpu_idle with preempt disabled */
441 cpu_startup_entry(CPUHP_ONLINE);
444 /* Check for early params. */
445 static int __init do_early_param(char *param, char *val,
446 const char *unused, void *arg)
448 const struct obs_kernel_param *p;
450 for (p = __setup_start; p < __setup_end; p++) {
451 if ((p->early && parameq(param, p->str)) ||
452 (strcmp(param, "console") == 0 &&
453 strcmp(p->str, "earlycon") == 0)
455 if (p->setup_func(val) != 0)
456 pr_warn("Malformed early option '%s'\n", param);
459 /* We accept everything at this stage. */
463 void __init parse_early_options(char *cmdline)
465 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
469 /* Arch code calls this early on, or if not, just before other parsing. */
470 void __init parse_early_param(void)
472 static int done __initdata;
473 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
478 /* All fall through to do_early_param. */
479 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
480 parse_early_options(tmp_cmdline);
484 void __init __weak arch_post_acpi_subsys_init(void) { }
486 void __init __weak smp_setup_processor_id(void)
490 # if THREAD_SIZE >= PAGE_SIZE
491 void __init __weak thread_stack_cache_init(void)
496 void __init __weak mem_encrypt_init(void) { }
499 core_param(initcall_debug, initcall_debug, bool, 0644);
501 #ifdef TRACEPOINTS_ENABLED
502 static void __init initcall_debug_enable(void);
504 static inline void initcall_debug_enable(void)
510 * Set up kernel memory allocators
512 static void __init mm_init(void)
515 * page_ext requires contiguous pages,
516 * bigger than MAX_ORDER unless SPARSEMEM.
518 page_ext_init_flatmem();
524 /* Should be run before the first non-init thread is created */
526 /* Should be run after espfix64 is set up. */
530 asmlinkage __visible void __init start_kernel(void)
535 set_task_stack_end_magic(&init_task);
536 smp_setup_processor_id();
537 debug_objects_early_init();
542 early_boot_irqs_disabled = true;
545 * Interrupts are still disabled. Do necessary setups, then
550 pr_notice("%s", linux_banner);
551 setup_arch(&command_line);
553 * Set up the the initial canary and entropy after arch
554 * and after adding latent and command line entropy.
556 add_latent_entropy();
557 add_device_randomness(command_line, strlen(command_line));
558 boot_init_stack_canary();
559 mm_init_cpumask(&init_mm);
560 setup_command_line(command_line);
562 setup_per_cpu_areas();
563 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
564 boot_cpu_hotplug_init();
566 build_all_zonelists(NULL);
569 pr_notice("Kernel command line: %s\n", boot_command_line);
570 /* parameters may set static keys */
573 after_dashes = parse_args("Booting kernel",
574 static_command_line, __start___param,
575 __stop___param - __start___param,
576 -1, -1, NULL, &unknown_bootoption);
577 if (!IS_ERR_OR_NULL(after_dashes))
578 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
582 * These use large bootmem allocations and must precede
586 vfs_caches_init_early();
593 /* trace_printk can be enabled here */
597 * Set up the scheduler prior starting any interrupts (such as the
598 * timer interrupt). Full topology setup happens at smp_init()
599 * time - but meanwhile we still have a functioning scheduler.
603 * Disable preemption - early bootup scheduling is extremely
604 * fragile until we cpu_idle() for the first time.
607 if (WARN(!irqs_disabled(),
608 "Interrupts were enabled *very* early, fixing it\n"))
613 * Set up housekeeping before setting up workqueues to allow the unbound
614 * workqueue to take non-housekeeping into account.
619 * Allow workqueue creation and work item queueing/cancelling
620 * early. Work item execution depends on kthreads and starts after
623 workqueue_init_early();
627 /* Trace events are available after this */
631 initcall_debug_enable();
633 context_tracking_init();
634 /* init some links before init_ISA_irqs() */
646 call_function_init();
647 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
649 early_boot_irqs_disabled = false;
652 kmem_cache_init_late();
655 * HACK ALERT! This is early. We're enabling the console before
656 * we've done PCI setups etc, and console_init() must be aware of
657 * this. But we do want output early, in case something goes wrong.
661 panic("Too many boot %s vars at `%s'", panic_later,
667 * Need to run this when irqs are enabled, because it wants
668 * to self-test [hard/soft]-irqs on/off lock inversion bugs
674 * This needs to be called before any devices perform DMA
675 * operations that might use the SWIOTLB bounce buffers. It will
676 * mark the bounce buffers as decrypted so that their usage will
677 * not cause "plain-text" data to be decrypted when accessed.
681 #ifdef CONFIG_BLK_DEV_INITRD
682 if (initrd_start && !initrd_below_start_ok &&
683 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
684 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
685 page_to_pfn(virt_to_page((void *)initrd_start)),
691 debug_objects_mem_init();
692 setup_per_cpu_pageset();
702 if (efi_enabled(EFI_RUNTIME_SERVICES))
703 efi_enter_virtual_mode();
705 thread_stack_cache_init();
722 taskstats_init_early();
727 acpi_subsystem_init();
728 arch_post_acpi_subsys_init();
731 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
732 efi_free_boot_services();
735 /* Do the rest non-__init'ed, we're now alive */
738 prevent_tail_call_optimization();
741 /* Call all constructor functions linked into the kernel. */
742 static void __init do_ctors(void)
744 #ifdef CONFIG_CONSTRUCTORS
745 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
747 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
752 #ifdef CONFIG_KALLSYMS
753 struct blacklist_entry {
754 struct list_head next;
758 static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
760 static int __init initcall_blacklist(char *str)
763 struct blacklist_entry *entry;
765 /* str argument is a comma-separated list of functions */
767 str_entry = strsep(&str, ",");
769 pr_debug("blacklisting initcall %s\n", str_entry);
770 entry = alloc_bootmem(sizeof(*entry));
771 entry->buf = alloc_bootmem(strlen(str_entry) + 1);
772 strcpy(entry->buf, str_entry);
773 list_add(&entry->next, &blacklisted_initcalls);
780 static bool __init_or_module initcall_blacklisted(initcall_t fn)
782 struct blacklist_entry *entry;
783 char fn_name[KSYM_SYMBOL_LEN];
786 if (list_empty(&blacklisted_initcalls))
789 addr = (unsigned long) dereference_function_descriptor(fn);
790 sprint_symbol_no_offset(fn_name, addr);
793 * fn will be "function_name [module_name]" where [module_name] is not
794 * displayed for built-in init functions. Strip off the [module_name].
796 strreplace(fn_name, ' ', '\0');
798 list_for_each_entry(entry, &blacklisted_initcalls, next) {
799 if (!strcmp(fn_name, entry->buf)) {
800 pr_debug("initcall %s blacklisted\n", fn_name);
808 static int __init initcall_blacklist(char *str)
810 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
814 static bool __init_or_module initcall_blacklisted(initcall_t fn)
819 __setup("initcall_blacklist=", initcall_blacklist);
821 static __init_or_module void
822 trace_initcall_start_cb(void *data, initcall_t fn)
824 ktime_t *calltime = (ktime_t *)data;
826 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
827 *calltime = ktime_get();
830 static __init_or_module void
831 trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
833 ktime_t *calltime = (ktime_t *)data;
834 ktime_t delta, rettime;
835 unsigned long long duration;
837 rettime = ktime_get();
838 delta = ktime_sub(rettime, *calltime);
839 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
840 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n",
844 static ktime_t initcall_calltime;
846 #ifdef TRACEPOINTS_ENABLED
847 static void __init initcall_debug_enable(void)
851 ret = register_trace_initcall_start(trace_initcall_start_cb,
853 ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
855 WARN(ret, "Failed to register initcall tracepoints\n");
857 # define do_trace_initcall_start trace_initcall_start
858 # define do_trace_initcall_finish trace_initcall_finish
860 static inline void do_trace_initcall_start(initcall_t fn)
864 trace_initcall_start_cb(&initcall_calltime, fn);
866 static inline void do_trace_initcall_finish(initcall_t fn, int ret)
870 trace_initcall_finish_cb(&initcall_calltime, fn, ret);
872 #endif /* !TRACEPOINTS_ENABLED */
874 int __init_or_module do_one_initcall(initcall_t fn)
876 int count = preempt_count();
880 if (initcall_blacklisted(fn))
883 do_trace_initcall_start(fn);
885 do_trace_initcall_finish(fn, ret);
889 if (preempt_count() != count) {
890 sprintf(msgbuf, "preemption imbalance ");
891 preempt_count_set(count);
893 if (irqs_disabled()) {
894 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
897 WARN(msgbuf[0], "initcall %pF returned with %s\n", fn, msgbuf);
899 add_latent_entropy();
904 extern initcall_entry_t __initcall_start[];
905 extern initcall_entry_t __initcall0_start[];
906 extern initcall_entry_t __initcall1_start[];
907 extern initcall_entry_t __initcall2_start[];
908 extern initcall_entry_t __initcall3_start[];
909 extern initcall_entry_t __initcall4_start[];
910 extern initcall_entry_t __initcall5_start[];
911 extern initcall_entry_t __initcall6_start[];
912 extern initcall_entry_t __initcall7_start[];
913 extern initcall_entry_t __initcall_end[];
915 static initcall_entry_t *initcall_levels[] __initdata = {
927 /* Keep these in sync with initcalls in include/linux/init.h */
928 static char *initcall_level_names[] __initdata = {
939 static void __init do_initcall_level(int level)
941 initcall_entry_t *fn;
943 strcpy(initcall_command_line, saved_command_line);
944 parse_args(initcall_level_names[level],
945 initcall_command_line, __start___param,
946 __stop___param - __start___param,
948 NULL, &repair_env_string);
950 trace_initcall_level(initcall_level_names[level]);
951 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
952 do_one_initcall(initcall_from_entry(fn));
955 static void __init do_initcalls(void)
959 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
960 do_initcall_level(level);
964 * Ok, the machine is now initialized. None of the devices
965 * have been touched yet, but the CPU subsystem is up and
966 * running, and memory and process management works.
968 * Now we can finally start doing some real work..
970 static void __init do_basic_setup(void)
977 usermodehelper_enable();
981 static void __init do_pre_smp_initcalls(void)
983 initcall_entry_t *fn;
985 trace_initcall_level("early");
986 for (fn = __initcall_start; fn < __initcall0_start; fn++)
987 do_one_initcall(initcall_from_entry(fn));
991 * This function requests modules which should be loaded by default and is
992 * called twice right after initrd is mounted and right before init is
993 * exec'd. If such modules are on either initrd or rootfs, they will be
994 * loaded before control is passed to userland.
996 void __init load_default_modules(void)
998 load_default_elevator_module();
1001 static int run_init_process(const char *init_filename)
1003 argv_init[0] = init_filename;
1004 pr_info("Run %s as init process\n", init_filename);
1005 return do_execve(getname_kernel(init_filename),
1006 (const char __user *const __user *)argv_init,
1007 (const char __user *const __user *)envp_init);
1010 static int try_to_run_init_process(const char *init_filename)
1014 ret = run_init_process(init_filename);
1016 if (ret && ret != -ENOENT) {
1017 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1018 init_filename, ret);
1024 static noinline void __init kernel_init_freeable(void);
1026 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1027 bool rodata_enabled __ro_after_init = true;
1028 static int __init set_debug_rodata(char *str)
1030 return strtobool(str, &rodata_enabled);
1032 __setup("rodata=", set_debug_rodata);
1035 #ifdef CONFIG_STRICT_KERNEL_RWX
1036 static void mark_readonly(void)
1038 if (rodata_enabled) {
1040 * load_module() results in W+X mappings, which are cleaned up
1041 * with call_rcu_sched(). Let's make sure that queued work is
1042 * flushed so that we don't hit false positives looking for
1043 * insecure pages which are W+X.
1045 rcu_barrier_sched();
1049 pr_info("Kernel memory protection disabled.\n");
1052 static inline void mark_readonly(void)
1054 pr_warn("This architecture does not have kernel memory protection.\n");
1058 static int __ref kernel_init(void *unused)
1062 kernel_init_freeable();
1063 /* need to finish all async __init code before freeing the memory */
1064 async_synchronize_full();
1065 ftrace_free_init_mem();
1066 jump_label_invalidate_initmem();
1071 * Kernel mappings are now finalized - update the userspace page-table
1076 system_state = SYSTEM_RUNNING;
1077 numa_default_policy();
1079 rcu_end_inkernel_boot();
1081 if (ramdisk_execute_command) {
1082 ret = run_init_process(ramdisk_execute_command);
1085 pr_err("Failed to execute %s (error %d)\n",
1086 ramdisk_execute_command, ret);
1090 * We try each of these until one succeeds.
1092 * The Bourne shell can be used instead of init if we are
1093 * trying to recover a really broken machine.
1095 if (execute_command) {
1096 ret = run_init_process(execute_command);
1099 panic("Requested init %s failed (error %d).",
1100 execute_command, ret);
1102 if (!try_to_run_init_process("/sbin/init") ||
1103 !try_to_run_init_process("/etc/init") ||
1104 !try_to_run_init_process("/bin/init") ||
1105 !try_to_run_init_process("/bin/sh"))
1108 panic("No working init found. Try passing init= option to kernel. "
1109 "See Linux Documentation/admin-guide/init.rst for guidance.");
1112 static noinline void __init kernel_init_freeable(void)
1115 * Wait until kthreadd is all set-up.
1117 wait_for_completion(&kthreadd_done);
1119 /* Now the scheduler is fully set up and can do blocking allocations */
1120 gfp_allowed_mask = __GFP_BITS_MASK;
1123 * init can allocate pages on any node
1125 set_mems_allowed(node_states[N_MEMORY]);
1127 cad_pid = get_pid(task_pid(current));
1129 smp_prepare_cpus(setup_max_cpus);
1133 init_mm_internals();
1135 do_pre_smp_initcalls();
1136 lockup_detector_init();
1141 page_alloc_init_late();
1142 /* Initialize page ext after all struct pages are initialized. */
1147 /* Open the /dev/console on the rootfs, this should never fail */
1148 if (ksys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
1149 pr_err("Warning: unable to open an initial console.\n");
1154 * check if there is an early userspace init. If yes, let it do all
1158 if (!ramdisk_execute_command)
1159 ramdisk_execute_command = "/init";
1161 if (ksys_access((const char __user *)
1162 ramdisk_execute_command, 0) != 0) {
1163 ramdisk_execute_command = NULL;
1164 prepare_namespace();
1168 * Ok, we have completed the initial bootup, and
1169 * we're essentially up and running. Get rid of the
1170 * initmem segments and start the user-mode stuff..
1172 * rootfs is available now, try loading the public keys
1173 * and default modules
1176 integrity_load_keys();
1177 load_default_modules();