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/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>
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_alloc(strlen(boot_command_line
) + 1, SMP_CACHE_BYTES
);
378 initcall_command_line
=
379 memblock_alloc(strlen(boot_command_line
) + 1, SMP_CACHE_BYTES
);
380 static_command_line
= memblock_alloc(strlen(command_line
) + 1,
382 strcpy(saved_command_line
, boot_command_line
);
383 strcpy(static_command_line
, command_line
);
387 * We need to finalize in a non-__init function or else race conditions
388 * between the root thread and the init thread may cause start_kernel to
389 * be reaped by free_initmem before the root thread has proceeded to
392 * gcc-3.4 accidentally inlines this function, so use noinline.
395 static __initdata
DECLARE_COMPLETION(kthreadd_done
);
397 noinline
void __ref
rest_init(void)
399 struct task_struct
*tsk
;
402 rcu_scheduler_starting();
404 * We need to spawn init first so that it obtains pid 1, however
405 * the init task will end up wanting to create kthreads, which, if
406 * we schedule it before we create kthreadd, will OOPS.
408 pid
= kernel_thread(kernel_init
, NULL
, CLONE_FS
);
410 * Pin init on the boot CPU. Task migration is not properly working
411 * until sched_init_smp() has been run. It will set the allowed
412 * CPUs for init to the non isolated CPUs.
415 tsk
= find_task_by_pid_ns(pid
, &init_pid_ns
);
416 set_cpus_allowed_ptr(tsk
, cpumask_of(smp_processor_id()));
419 numa_default_policy();
420 pid
= kernel_thread(kthreadd
, NULL
, CLONE_FS
| CLONE_FILES
);
422 kthreadd_task
= find_task_by_pid_ns(pid
, &init_pid_ns
);
426 * Enable might_sleep() and smp_processor_id() checks.
427 * They cannot be enabled earlier because with CONFIG_PREEMPT=y
428 * kernel_thread() would trigger might_sleep() splats. With
429 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
430 * already, but it's stuck on the kthreadd_done completion.
432 system_state
= SYSTEM_SCHEDULING
;
434 complete(&kthreadd_done
);
437 * The boot idle thread must execute schedule()
438 * at least once to get things moving:
440 schedule_preempt_disabled();
441 /* Call into cpu_idle with preempt disabled */
442 cpu_startup_entry(CPUHP_ONLINE
);
445 /* Check for early params. */
446 static int __init
do_early_param(char *param
, char *val
,
447 const char *unused
, void *arg
)
449 const struct obs_kernel_param
*p
;
451 for (p
= __setup_start
; p
< __setup_end
; p
++) {
452 if ((p
->early
&& parameq(param
, p
->str
)) ||
453 (strcmp(param
, "console") == 0 &&
454 strcmp(p
->str
, "earlycon") == 0)
456 if (p
->setup_func(val
) != 0)
457 pr_warn("Malformed early option '%s'\n", param
);
460 /* We accept everything at this stage. */
464 void __init
parse_early_options(char *cmdline
)
466 parse_args("early options", cmdline
, NULL
, 0, 0, 0, NULL
,
470 /* Arch code calls this early on, or if not, just before other parsing. */
471 void __init
parse_early_param(void)
473 static int done __initdata
;
474 static char tmp_cmdline
[COMMAND_LINE_SIZE
] __initdata
;
479 /* All fall through to do_early_param. */
480 strlcpy(tmp_cmdline
, boot_command_line
, COMMAND_LINE_SIZE
);
481 parse_early_options(tmp_cmdline
);
485 void __init __weak
arch_post_acpi_subsys_init(void) { }
487 void __init __weak
smp_setup_processor_id(void)
491 # if THREAD_SIZE >= PAGE_SIZE
492 void __init __weak
thread_stack_cache_init(void)
497 void __init __weak
mem_encrypt_init(void) { }
500 core_param(initcall_debug
, initcall_debug
, bool, 0644);
502 #ifdef TRACEPOINTS_ENABLED
503 static void __init
initcall_debug_enable(void);
505 static inline void initcall_debug_enable(void)
511 * Set up kernel memory allocators
513 static void __init
mm_init(void)
516 * page_ext requires contiguous pages,
517 * bigger than MAX_ORDER unless SPARSEMEM.
519 page_ext_init_flatmem();
523 debug_objects_mem_init();
526 /* Should be run before the first non-init thread is created */
528 /* Should be run after espfix64 is set up. */
532 void __init __weak
arch_call_rest_init(void)
537 asmlinkage __visible
void __init
start_kernel(void)
542 set_task_stack_end_magic(&init_task
);
543 smp_setup_processor_id();
544 debug_objects_early_init();
549 early_boot_irqs_disabled
= true;
552 * Interrupts are still disabled. Do necessary setups, then
557 pr_notice("%s", linux_banner
);
558 setup_arch(&command_line
);
560 * Set up the the initial canary and entropy after arch
561 * and after adding latent and command line entropy.
563 add_latent_entropy();
564 add_device_randomness(command_line
, strlen(command_line
));
565 boot_init_stack_canary();
566 mm_init_cpumask(&init_mm
);
567 setup_command_line(command_line
);
569 setup_per_cpu_areas();
570 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
571 boot_cpu_hotplug_init();
573 build_all_zonelists(NULL
);
576 pr_notice("Kernel command line: %s\n", boot_command_line
);
578 after_dashes
= parse_args("Booting kernel",
579 static_command_line
, __start___param
,
580 __stop___param
- __start___param
,
581 -1, -1, NULL
, &unknown_bootoption
);
582 if (!IS_ERR_OR_NULL(after_dashes
))
583 parse_args("Setting init args", after_dashes
, NULL
, 0, -1, -1,
589 * These use large bootmem allocations and must precede
593 vfs_caches_init_early();
600 /* trace_printk can be enabled here */
604 * Set up the scheduler prior starting any interrupts (such as the
605 * timer interrupt). Full topology setup happens at smp_init()
606 * time - but meanwhile we still have a functioning scheduler.
610 * Disable preemption - early bootup scheduling is extremely
611 * fragile until we cpu_idle() for the first time.
614 if (WARN(!irqs_disabled(),
615 "Interrupts were enabled *very* early, fixing it\n"))
620 * Set up housekeeping before setting up workqueues to allow the unbound
621 * workqueue to take non-housekeeping into account.
626 * Allow workqueue creation and work item queueing/cancelling
627 * early. Work item execution depends on kthreads and starts after
630 workqueue_init_early();
634 /* Trace events are available after this */
638 initcall_debug_enable();
640 context_tracking_init();
641 /* init some links before init_ISA_irqs() */
654 call_function_init();
655 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
657 early_boot_irqs_disabled
= false;
660 kmem_cache_init_late();
663 * HACK ALERT! This is early. We're enabling the console before
664 * we've done PCI setups etc, and console_init() must be aware of
665 * this. But we do want output early, in case something goes wrong.
669 panic("Too many boot %s vars at `%s'", panic_later
,
675 * Need to run this when irqs are enabled, because it wants
676 * to self-test [hard/soft]-irqs on/off lock inversion bugs
682 * This needs to be called before any devices perform DMA
683 * operations that might use the SWIOTLB bounce buffers. It will
684 * mark the bounce buffers as decrypted so that their usage will
685 * not cause "plain-text" data to be decrypted when accessed.
689 #ifdef CONFIG_BLK_DEV_INITRD
690 if (initrd_start
&& !initrd_below_start_ok
&&
691 page_to_pfn(virt_to_page((void *)initrd_start
)) < min_low_pfn
) {
692 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
693 page_to_pfn(virt_to_page((void *)initrd_start
)),
699 setup_per_cpu_pageset();
709 if (efi_enabled(EFI_RUNTIME_SERVICES
))
710 efi_enter_virtual_mode();
712 thread_stack_cache_init();
729 taskstats_init_early();
734 acpi_subsystem_init();
735 arch_post_acpi_subsys_init();
738 /* Do the rest non-__init'ed, we're now alive */
739 arch_call_rest_init();
742 /* Call all constructor functions linked into the kernel. */
743 static void __init
do_ctors(void)
745 #ifdef CONFIG_CONSTRUCTORS
746 ctor_fn_t
*fn
= (ctor_fn_t
*) __ctors_start
;
748 for (; fn
< (ctor_fn_t
*) __ctors_end
; fn
++)
753 #ifdef CONFIG_KALLSYMS
754 struct blacklist_entry
{
755 struct list_head next
;
759 static __initdata_or_module
LIST_HEAD(blacklisted_initcalls
);
761 static int __init
initcall_blacklist(char *str
)
764 struct blacklist_entry
*entry
;
766 /* str argument is a comma-separated list of functions */
768 str_entry
= strsep(&str
, ",");
770 pr_debug("blacklisting initcall %s\n", str_entry
);
771 entry
= memblock_alloc(sizeof(*entry
),
773 entry
->buf
= memblock_alloc(strlen(str_entry
) + 1,
775 strcpy(entry
->buf
, str_entry
);
776 list_add(&entry
->next
, &blacklisted_initcalls
);
783 static bool __init_or_module
initcall_blacklisted(initcall_t fn
)
785 struct blacklist_entry
*entry
;
786 char fn_name
[KSYM_SYMBOL_LEN
];
789 if (list_empty(&blacklisted_initcalls
))
792 addr
= (unsigned long) dereference_function_descriptor(fn
);
793 sprint_symbol_no_offset(fn_name
, addr
);
796 * fn will be "function_name [module_name]" where [module_name] is not
797 * displayed for built-in init functions. Strip off the [module_name].
799 strreplace(fn_name
, ' ', '\0');
801 list_for_each_entry(entry
, &blacklisted_initcalls
, next
) {
802 if (!strcmp(fn_name
, entry
->buf
)) {
803 pr_debug("initcall %s blacklisted\n", fn_name
);
811 static int __init
initcall_blacklist(char *str
)
813 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
817 static bool __init_or_module
initcall_blacklisted(initcall_t fn
)
822 __setup("initcall_blacklist=", initcall_blacklist
);
824 static __init_or_module
void
825 trace_initcall_start_cb(void *data
, initcall_t fn
)
827 ktime_t
*calltime
= (ktime_t
*)data
;
829 printk(KERN_DEBUG
"calling %pF @ %i\n", fn
, task_pid_nr(current
));
830 *calltime
= ktime_get();
833 static __init_or_module
void
834 trace_initcall_finish_cb(void *data
, initcall_t fn
, int ret
)
836 ktime_t
*calltime
= (ktime_t
*)data
;
837 ktime_t delta
, rettime
;
838 unsigned long long duration
;
840 rettime
= ktime_get();
841 delta
= ktime_sub(rettime
, *calltime
);
842 duration
= (unsigned long long) ktime_to_ns(delta
) >> 10;
843 printk(KERN_DEBUG
"initcall %pF returned %d after %lld usecs\n",
847 static ktime_t initcall_calltime
;
849 #ifdef TRACEPOINTS_ENABLED
850 static void __init
initcall_debug_enable(void)
854 ret
= register_trace_initcall_start(trace_initcall_start_cb
,
856 ret
|= register_trace_initcall_finish(trace_initcall_finish_cb
,
858 WARN(ret
, "Failed to register initcall tracepoints\n");
860 # define do_trace_initcall_start trace_initcall_start
861 # define do_trace_initcall_finish trace_initcall_finish
863 static inline void do_trace_initcall_start(initcall_t fn
)
867 trace_initcall_start_cb(&initcall_calltime
, fn
);
869 static inline void do_trace_initcall_finish(initcall_t fn
, int ret
)
873 trace_initcall_finish_cb(&initcall_calltime
, fn
, ret
);
875 #endif /* !TRACEPOINTS_ENABLED */
877 int __init_or_module
do_one_initcall(initcall_t fn
)
879 int count
= preempt_count();
883 if (initcall_blacklisted(fn
))
886 do_trace_initcall_start(fn
);
888 do_trace_initcall_finish(fn
, ret
);
892 if (preempt_count() != count
) {
893 sprintf(msgbuf
, "preemption imbalance ");
894 preempt_count_set(count
);
896 if (irqs_disabled()) {
897 strlcat(msgbuf
, "disabled interrupts ", sizeof(msgbuf
));
900 WARN(msgbuf
[0], "initcall %pF returned with %s\n", fn
, msgbuf
);
902 add_latent_entropy();
907 extern initcall_entry_t __initcall_start
[];
908 extern initcall_entry_t __initcall0_start
[];
909 extern initcall_entry_t __initcall1_start
[];
910 extern initcall_entry_t __initcall2_start
[];
911 extern initcall_entry_t __initcall3_start
[];
912 extern initcall_entry_t __initcall4_start
[];
913 extern initcall_entry_t __initcall5_start
[];
914 extern initcall_entry_t __initcall6_start
[];
915 extern initcall_entry_t __initcall7_start
[];
916 extern initcall_entry_t __initcall_end
[];
918 static initcall_entry_t
*initcall_levels
[] __initdata
= {
930 /* Keep these in sync with initcalls in include/linux/init.h */
931 static const char *initcall_level_names
[] __initdata
= {
942 static void __init
do_initcall_level(int level
)
944 initcall_entry_t
*fn
;
946 strcpy(initcall_command_line
, saved_command_line
);
947 parse_args(initcall_level_names
[level
],
948 initcall_command_line
, __start___param
,
949 __stop___param
- __start___param
,
951 NULL
, &repair_env_string
);
953 trace_initcall_level(initcall_level_names
[level
]);
954 for (fn
= initcall_levels
[level
]; fn
< initcall_levels
[level
+1]; fn
++)
955 do_one_initcall(initcall_from_entry(fn
));
958 static void __init
do_initcalls(void)
962 for (level
= 0; level
< ARRAY_SIZE(initcall_levels
) - 1; level
++)
963 do_initcall_level(level
);
967 * Ok, the machine is now initialized. None of the devices
968 * have been touched yet, but the CPU subsystem is up and
969 * running, and memory and process management works.
971 * Now we can finally start doing some real work..
973 static void __init
do_basic_setup(void)
980 usermodehelper_enable();
984 static void __init
do_pre_smp_initcalls(void)
986 initcall_entry_t
*fn
;
988 trace_initcall_level("early");
989 for (fn
= __initcall_start
; fn
< __initcall0_start
; fn
++)
990 do_one_initcall(initcall_from_entry(fn
));
993 static int run_init_process(const char *init_filename
)
995 argv_init
[0] = init_filename
;
996 pr_info("Run %s as init process\n", init_filename
);
997 return do_execve(getname_kernel(init_filename
),
998 (const char __user
*const __user
*)argv_init
,
999 (const char __user
*const __user
*)envp_init
);
1002 static int try_to_run_init_process(const char *init_filename
)
1006 ret
= run_init_process(init_filename
);
1008 if (ret
&& ret
!= -ENOENT
) {
1009 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1010 init_filename
, ret
);
1016 static noinline
void __init
kernel_init_freeable(void);
1018 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1019 bool rodata_enabled __ro_after_init
= true;
1020 static int __init
set_debug_rodata(char *str
)
1022 return strtobool(str
, &rodata_enabled
);
1024 __setup("rodata=", set_debug_rodata
);
1027 #ifdef CONFIG_STRICT_KERNEL_RWX
1028 static void mark_readonly(void)
1030 if (rodata_enabled
) {
1032 * load_module() results in W+X mappings, which are cleaned
1033 * up with call_rcu(). Let's make sure that queued work is
1034 * flushed so that we don't hit false positives looking for
1035 * insecure pages which are W+X.
1041 pr_info("Kernel memory protection disabled.\n");
1044 static inline void mark_readonly(void)
1046 pr_warn("This architecture does not have kernel memory protection.\n");
1050 static int __ref
kernel_init(void *unused
)
1054 kernel_init_freeable();
1055 /* need to finish all async __init code before freeing the memory */
1056 async_synchronize_full();
1057 ftrace_free_init_mem();
1062 * Kernel mappings are now finalized - update the userspace page-table
1067 system_state
= SYSTEM_RUNNING
;
1068 numa_default_policy();
1070 rcu_end_inkernel_boot();
1072 if (ramdisk_execute_command
) {
1073 ret
= run_init_process(ramdisk_execute_command
);
1076 pr_err("Failed to execute %s (error %d)\n",
1077 ramdisk_execute_command
, ret
);
1081 * We try each of these until one succeeds.
1083 * The Bourne shell can be used instead of init if we are
1084 * trying to recover a really broken machine.
1086 if (execute_command
) {
1087 ret
= run_init_process(execute_command
);
1090 panic("Requested init %s failed (error %d).",
1091 execute_command
, ret
);
1093 if (!try_to_run_init_process("/sbin/init") ||
1094 !try_to_run_init_process("/etc/init") ||
1095 !try_to_run_init_process("/bin/init") ||
1096 !try_to_run_init_process("/bin/sh"))
1099 panic("No working init found. Try passing init= option to kernel. "
1100 "See Linux Documentation/admin-guide/init.rst for guidance.");
1103 static noinline
void __init
kernel_init_freeable(void)
1106 * Wait until kthreadd is all set-up.
1108 wait_for_completion(&kthreadd_done
);
1110 /* Now the scheduler is fully set up and can do blocking allocations */
1111 gfp_allowed_mask
= __GFP_BITS_MASK
;
1114 * init can allocate pages on any node
1116 set_mems_allowed(node_states
[N_MEMORY
]);
1118 cad_pid
= task_pid(current
);
1120 smp_prepare_cpus(setup_max_cpus
);
1124 init_mm_internals();
1126 do_pre_smp_initcalls();
1127 lockup_detector_init();
1132 page_alloc_init_late();
1133 /* Initialize page ext after all struct pages are initialized. */
1138 /* Open the /dev/console on the rootfs, this should never fail */
1139 if (ksys_open((const char __user
*) "/dev/console", O_RDWR
, 0) < 0)
1140 pr_err("Warning: unable to open an initial console.\n");
1145 * check if there is an early userspace init. If yes, let it do all
1149 if (!ramdisk_execute_command
)
1150 ramdisk_execute_command
= "/init";
1152 if (ksys_access((const char __user
*)
1153 ramdisk_execute_command
, 0) != 0) {
1154 ramdisk_execute_command
= NULL
;
1155 prepare_namespace();
1159 * Ok, we have completed the initial bootup, and
1160 * we're essentially up and running. Get rid of the
1161 * initmem segments and start the user-mode stuff..
1163 * rootfs is available now, try loading the public keys
1164 * and default modules
1167 integrity_load_keys();