1 // SPDX-License-Identifier: GPL-2.0-only
5 * Copyright (C) 1991, 1992 Linus Torvalds
7 * GK 2/5/95 - Changed to support mounting root fs via NFS
8 * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
9 * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
10 * Simplified starting of init: Michael A. Griffith <grif@acm.org>
13 #define DEBUG /* Enable initcall_debug */
15 #include <linux/types.h>
16 #include <linux/extable.h>
17 #include <linux/module.h>
18 #include <linux/proc_fs.h>
19 #include <linux/binfmts.h>
20 #include <linux/kernel.h>
21 #include <linux/syscalls.h>
22 #include <linux/stackprotector.h>
23 #include <linux/string.h>
24 #include <linux/ctype.h>
25 #include <linux/delay.h>
26 #include <linux/ioport.h>
27 #include <linux/init.h>
28 #include <linux/initrd.h>
29 #include <linux/memblock.h>
30 #include <linux/acpi.h>
31 #include <linux/bootconfig.h>
32 #include <linux/console.h>
33 #include <linux/nmi.h>
34 #include <linux/percpu.h>
35 #include <linux/kmod.h>
36 #include <linux/kprobes.h>
37 #include <linux/vmalloc.h>
38 #include <linux/kernel_stat.h>
39 #include <linux/start_kernel.h>
40 #include <linux/security.h>
41 #include <linux/smp.h>
42 #include <linux/profile.h>
43 #include <linux/kfence.h>
44 #include <linux/rcupdate.h>
45 #include <linux/moduleparam.h>
46 #include <linux/kallsyms.h>
47 #include <linux/writeback.h>
48 #include <linux/cpu.h>
49 #include <linux/cpuset.h>
50 #include <linux/cgroup.h>
51 #include <linux/efi.h>
52 #include <linux/tick.h>
53 #include <linux/sched/isolation.h>
54 #include <linux/interrupt.h>
55 #include <linux/taskstats_kern.h>
56 #include <linux/delayacct.h>
57 #include <linux/unistd.h>
58 #include <linux/utsname.h>
59 #include <linux/rmap.h>
60 #include <linux/mempolicy.h>
61 #include <linux/key.h>
62 #include <linux/page_ext.h>
63 #include <linux/debug_locks.h>
64 #include <linux/debugobjects.h>
65 #include <linux/lockdep.h>
66 #include <linux/kmemleak.h>
67 #include <linux/padata.h>
68 #include <linux/pid_namespace.h>
69 #include <linux/device/driver.h>
70 #include <linux/kthread.h>
71 #include <linux/sched.h>
72 #include <linux/sched/init.h>
73 #include <linux/signal.h>
74 #include <linux/idr.h>
75 #include <linux/kgdb.h>
76 #include <linux/ftrace.h>
77 #include <linux/async.h>
78 #include <linux/shmem_fs.h>
79 #include <linux/slab.h>
80 #include <linux/perf_event.h>
81 #include <linux/ptrace.h>
82 #include <linux/pti.h>
83 #include <linux/blkdev.h>
84 #include <linux/elevator.h>
85 #include <linux/sched/clock.h>
86 #include <linux/sched/task.h>
87 #include <linux/sched/task_stack.h>
88 #include <linux/context_tracking.h>
89 #include <linux/random.h>
90 #include <linux/list.h>
91 #include <linux/integrity.h>
92 #include <linux/proc_ns.h>
94 #include <linux/cache.h>
95 #include <linux/rodata_test.h>
96 #include <linux/jump_label.h>
97 #include <linux/mem_encrypt.h>
98 #include <linux/kcsan.h>
99 #include <linux/init_syscalls.h>
100 #include <linux/stackdepot.h>
103 #include <asm/bugs.h>
104 #include <asm/setup.h>
105 #include <asm/sections.h>
106 #include <asm/cacheflush.h>
108 #define CREATE_TRACE_POINTS
109 #include <trace/events/initcall.h>
111 #include <kunit/test.h>
113 static int kernel_init(void *);
115 extern void init_IRQ(void);
116 extern void radix_tree_init(void);
119 * Debug helper: via this flag we know that we are in 'early bootup code'
120 * where only the boot processor is running with IRQ disabled. This means
121 * two things - IRQ must not be enabled before the flag is cleared and some
122 * operations which are not allowed with IRQ disabled are allowed while the
125 bool early_boot_irqs_disabled __read_mostly
;
127 enum system_states system_state __read_mostly
;
128 EXPORT_SYMBOL(system_state
);
131 * Boot command-line arguments
133 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
134 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
136 extern void time_init(void);
137 /* Default late time init is NULL. archs can override this later. */
138 void (*__initdata late_time_init
)(void);
140 /* Untouched command line saved by arch-specific code. */
141 char __initdata boot_command_line
[COMMAND_LINE_SIZE
];
142 /* Untouched saved command line (eg. for /proc) */
143 char *saved_command_line
;
144 /* Command line for parameter parsing */
145 static char *static_command_line
;
146 /* Untouched extra command line */
147 static char *extra_command_line
;
148 /* Extra init arguments */
149 static char *extra_init_args
;
151 #ifdef CONFIG_BOOT_CONFIG
152 /* Is bootconfig on command line? */
153 static bool bootconfig_found
;
154 static bool initargs_found
;
156 # define bootconfig_found false
157 # define initargs_found false
160 static char *execute_command
;
161 static char *ramdisk_execute_command
= "/init";
164 * Used to generate warnings if static_key manipulation functions are used
165 * before jump_label_init is called.
167 bool static_key_initialized __read_mostly
;
168 EXPORT_SYMBOL_GPL(static_key_initialized
);
171 * If set, this is an indication to the drivers that reset the underlying
172 * device before going ahead with the initialization otherwise driver might
173 * rely on the BIOS and skip the reset operation.
175 * This is useful if kernel is booting in an unreliable environment.
176 * For ex. kdump situation where previous kernel has crashed, BIOS has been
177 * skipped and devices will be in unknown state.
179 unsigned int reset_devices
;
180 EXPORT_SYMBOL(reset_devices
);
182 static int __init
set_reset_devices(char *str
)
188 __setup("reset_devices", set_reset_devices
);
190 static const char *argv_init
[MAX_INIT_ARGS
+2] = { "init", NULL
, };
191 const char *envp_init
[MAX_INIT_ENVS
+2] = { "HOME=/", "TERM=linux", NULL
, };
192 static const char *panic_later
, *panic_param
;
194 extern const struct obs_kernel_param __setup_start
[], __setup_end
[];
196 static bool __init
obsolete_checksetup(char *line
)
198 const struct obs_kernel_param
*p
;
199 bool had_early_param
= false;
203 int n
= strlen(p
->str
);
204 if (parameqn(line
, p
->str
, n
)) {
206 /* Already done in parse_early_param?
207 * (Needs exact match on param part).
208 * Keep iterating, as we can have early
209 * params and __setups of same names 8( */
210 if (line
[n
] == '\0' || line
[n
] == '=')
211 had_early_param
= true;
212 } else if (!p
->setup_func
) {
213 pr_warn("Parameter %s is obsolete, ignored\n",
216 } else if (p
->setup_func(line
+ n
))
220 } while (p
< __setup_end
);
222 return had_early_param
;
226 * This should be approx 2 Bo*oMips to start (note initial shift), and will
227 * still work even if initially too large, it will just take slightly longer
229 unsigned long loops_per_jiffy
= (1<<12);
230 EXPORT_SYMBOL(loops_per_jiffy
);
232 static int __init
debug_kernel(char *str
)
234 console_loglevel
= CONSOLE_LOGLEVEL_DEBUG
;
238 static int __init
quiet_kernel(char *str
)
240 console_loglevel
= CONSOLE_LOGLEVEL_QUIET
;
244 early_param("debug", debug_kernel
);
245 early_param("quiet", quiet_kernel
);
247 static int __init
loglevel(char *str
)
252 * Only update loglevel value when a correct setting was passed,
253 * to prevent blind crashes (when loglevel being set to 0) that
254 * are quite hard to debug
256 if (get_option(&str
, &newlevel
)) {
257 console_loglevel
= newlevel
;
264 early_param("loglevel", loglevel
);
266 #ifdef CONFIG_BLK_DEV_INITRD
267 static void * __init
get_boot_config_from_initrd(u32
*_size
, u32
*_csum
)
277 data
= (char *)initrd_end
- BOOTCONFIG_MAGIC_LEN
;
279 * Since Grub may align the size of initrd to 4, we must
280 * check the preceding 3 bytes as well.
282 for (i
= 0; i
< 4; i
++) {
283 if (!memcmp(data
, BOOTCONFIG_MAGIC
, BOOTCONFIG_MAGIC_LEN
))
290 hdr
= (u32
*)(data
- 8);
291 size
= le32_to_cpu(hdr
[0]);
292 csum
= le32_to_cpu(hdr
[1]);
294 data
= ((void *)hdr
) - size
;
295 if ((unsigned long)data
< initrd_start
) {
296 pr_err("bootconfig size %d is greater than initrd size %ld\n",
297 size
, initrd_end
- initrd_start
);
301 /* Remove bootconfig from initramfs/initrd */
302 initrd_end
= (unsigned long)data
;
311 static void * __init
get_boot_config_from_initrd(u32
*_size
, u32
*_csum
)
317 #ifdef CONFIG_BOOT_CONFIG
319 static char xbc_namebuf
[XBC_KEYLEN_MAX
] __initdata
;
321 #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
323 static int __init
xbc_snprint_cmdline(char *buf
, size_t size
,
324 struct xbc_node
*root
)
326 struct xbc_node
*knode
, *vnode
;
327 char *end
= buf
+ size
;
331 xbc_node_for_each_key_value(root
, knode
, val
) {
332 ret
= xbc_node_compose_key_after(root
, knode
,
333 xbc_namebuf
, XBC_KEYLEN_MAX
);
337 vnode
= xbc_node_get_child(knode
);
339 ret
= snprintf(buf
, rest(buf
, end
), "%s ", xbc_namebuf
);
345 xbc_array_for_each_value(vnode
, val
) {
346 ret
= snprintf(buf
, rest(buf
, end
), "%s=\"%s\" ",
354 return buf
- (end
- size
);
358 /* Make an extra command line under given key word */
359 static char * __init
xbc_make_cmdline(const char *key
)
361 struct xbc_node
*root
;
365 root
= xbc_find_node(key
);
369 /* Count required buffer size */
370 len
= xbc_snprint_cmdline(NULL
, 0, root
);
374 new_cmdline
= memblock_alloc(len
+ 1, SMP_CACHE_BYTES
);
376 pr_err("Failed to allocate memory for extra kernel cmdline.\n");
380 ret
= xbc_snprint_cmdline(new_cmdline
, len
+ 1, root
);
381 if (ret
< 0 || ret
> len
) {
382 pr_err("Failed to print extra kernel cmdline.\n");
389 static u32
boot_config_checksum(unsigned char *p
, u32 size
)
399 static int __init
bootconfig_params(char *param
, char *val
,
400 const char *unused
, void *arg
)
402 if (strcmp(param
, "bootconfig") == 0) {
403 bootconfig_found
= true;
408 static void __init
setup_boot_config(void)
410 static char tmp_cmdline
[COMMAND_LINE_SIZE
] __initdata
;
414 char *data
, *copy
, *err
;
417 /* Cut out the bootconfig data even if we have no bootconfig option */
418 data
= get_boot_config_from_initrd(&size
, &csum
);
420 strlcpy(tmp_cmdline
, boot_command_line
, COMMAND_LINE_SIZE
);
421 err
= parse_args("bootconfig", tmp_cmdline
, NULL
, 0, 0, 0, NULL
,
424 if (IS_ERR(err
) || !bootconfig_found
)
427 /* parse_args() stops at '--' and returns an address */
429 initargs_found
= true;
432 pr_err("'bootconfig' found on command line, but no bootconfig found\n");
436 if (size
>= XBC_DATA_MAX
) {
437 pr_err("bootconfig size %d greater than max size %d\n",
442 if (boot_config_checksum((unsigned char *)data
, size
) != csum
) {
443 pr_err("bootconfig checksum failed\n");
447 copy
= memblock_alloc(size
+ 1, SMP_CACHE_BYTES
);
449 pr_err("Failed to allocate memory for bootconfig\n");
453 memcpy(copy
, data
, size
);
456 ret
= xbc_init(copy
, &msg
, &pos
);
459 pr_err("Failed to init bootconfig: %s.\n", msg
);
461 pr_err("Failed to parse bootconfig: %s at %d.\n",
464 pr_info("Load bootconfig: %d bytes %d nodes\n", size
, ret
);
465 /* keys starting with "kernel." are passed via cmdline */
466 extra_command_line
= xbc_make_cmdline("kernel");
467 /* Also, "init." keys are init arguments */
468 extra_init_args
= xbc_make_cmdline("init");
475 static void __init
setup_boot_config(void)
477 /* Remove bootconfig data from initrd */
478 get_boot_config_from_initrd(NULL
, NULL
);
481 static int __init
warn_bootconfig(char *str
)
483 pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
486 early_param("bootconfig", warn_bootconfig
);
490 /* Change NUL term back to "=", to make "param" the whole string. */
491 static void __init
repair_env_string(char *param
, char *val
)
494 /* param=val or param="val"? */
495 if (val
== param
+strlen(param
)+1)
497 else if (val
== param
+strlen(param
)+2) {
499 memmove(val
-1, val
, strlen(val
)+1);
505 /* Anything after -- gets handed straight to init. */
506 static int __init
set_init_arg(char *param
, char *val
,
507 const char *unused
, void *arg
)
514 repair_env_string(param
, val
);
516 for (i
= 0; argv_init
[i
]; i
++) {
517 if (i
== MAX_INIT_ARGS
) {
518 panic_later
= "init";
523 argv_init
[i
] = param
;
528 * Unknown boot options get handed to init, unless they look like
529 * unused parameters (modprobe will find them in /proc/cmdline).
531 static int __init
unknown_bootoption(char *param
, char *val
,
532 const char *unused
, void *arg
)
534 size_t len
= strlen(param
);
536 repair_env_string(param
, val
);
538 /* Handle obsolete-style parameters */
539 if (obsolete_checksetup(param
))
542 /* Unused module parameter. */
543 if (strnchr(param
, len
, '.'))
550 /* Environment option */
552 for (i
= 0; envp_init
[i
]; i
++) {
553 if (i
== MAX_INIT_ENVS
) {
557 if (!strncmp(param
, envp_init
[i
], len
+1))
560 envp_init
[i
] = param
;
562 /* Command line option */
564 for (i
= 0; argv_init
[i
]; i
++) {
565 if (i
== MAX_INIT_ARGS
) {
566 panic_later
= "init";
570 argv_init
[i
] = param
;
575 static int __init
init_setup(char *str
)
579 execute_command
= str
;
581 * In case LILO is going to boot us with default command line,
582 * it prepends "auto" before the whole cmdline which makes
583 * the shell think it should execute a script with such name.
584 * So we ignore all arguments entered _before_ init=... [MJ]
586 for (i
= 1; i
< MAX_INIT_ARGS
; i
++)
590 __setup("init=", init_setup
);
592 static int __init
rdinit_setup(char *str
)
596 ramdisk_execute_command
= str
;
597 /* See "auto" comment in init_setup */
598 for (i
= 1; i
< MAX_INIT_ARGS
; i
++)
602 __setup("rdinit=", rdinit_setup
);
605 static const unsigned int setup_max_cpus
= NR_CPUS
;
606 static inline void setup_nr_cpu_ids(void) { }
607 static inline void smp_prepare_cpus(unsigned int maxcpus
) { }
611 * We need to store the untouched command line for future reference.
612 * We also need to store the touched command line since the parameter
613 * parsing is performed in place, and we should allow a component to
614 * store reference of name/value for future reference.
616 static void __init
setup_command_line(char *command_line
)
618 size_t len
, xlen
= 0, ilen
= 0;
620 if (extra_command_line
)
621 xlen
= strlen(extra_command_line
);
623 ilen
= strlen(extra_init_args
) + 4; /* for " -- " */
625 len
= xlen
+ strlen(boot_command_line
) + 1;
627 saved_command_line
= memblock_alloc(len
+ ilen
, SMP_CACHE_BYTES
);
628 if (!saved_command_line
)
629 panic("%s: Failed to allocate %zu bytes\n", __func__
, len
+ ilen
);
631 static_command_line
= memblock_alloc(len
, SMP_CACHE_BYTES
);
632 if (!static_command_line
)
633 panic("%s: Failed to allocate %zu bytes\n", __func__
, len
);
637 * We have to put extra_command_line before boot command
638 * lines because there could be dashes (separator of init
639 * command line) in the command lines.
641 strcpy(saved_command_line
, extra_command_line
);
642 strcpy(static_command_line
, extra_command_line
);
644 strcpy(saved_command_line
+ xlen
, boot_command_line
);
645 strcpy(static_command_line
+ xlen
, command_line
);
649 * Append supplemental init boot args to saved_command_line
650 * so that user can check what command line options passed
653 len
= strlen(saved_command_line
);
654 if (initargs_found
) {
655 saved_command_line
[len
++] = ' ';
657 strcpy(saved_command_line
+ len
, " -- ");
661 strcpy(saved_command_line
+ len
, extra_init_args
);
666 * We need to finalize in a non-__init function or else race conditions
667 * between the root thread and the init thread may cause start_kernel to
668 * be reaped by free_initmem before the root thread has proceeded to
671 * gcc-3.4 accidentally inlines this function, so use noinline.
674 static __initdata
DECLARE_COMPLETION(kthreadd_done
);
676 noinline
void __ref
rest_init(void)
678 struct task_struct
*tsk
;
681 rcu_scheduler_starting();
683 * We need to spawn init first so that it obtains pid 1, however
684 * the init task will end up wanting to create kthreads, which, if
685 * we schedule it before we create kthreadd, will OOPS.
687 pid
= kernel_thread(kernel_init
, NULL
, CLONE_FS
);
689 * Pin init on the boot CPU. Task migration is not properly working
690 * until sched_init_smp() has been run. It will set the allowed
691 * CPUs for init to the non isolated CPUs.
694 tsk
= find_task_by_pid_ns(pid
, &init_pid_ns
);
695 tsk
->flags
|= PF_NO_SETAFFINITY
;
696 set_cpus_allowed_ptr(tsk
, cpumask_of(smp_processor_id()));
699 numa_default_policy();
700 pid
= kernel_thread(kthreadd
, NULL
, CLONE_FS
| CLONE_FILES
);
702 kthreadd_task
= find_task_by_pid_ns(pid
, &init_pid_ns
);
706 * Enable might_sleep() and smp_processor_id() checks.
707 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
708 * kernel_thread() would trigger might_sleep() splats. With
709 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
710 * already, but it's stuck on the kthreadd_done completion.
712 system_state
= SYSTEM_SCHEDULING
;
714 complete(&kthreadd_done
);
717 * The boot idle thread must execute schedule()
718 * at least once to get things moving:
720 schedule_preempt_disabled();
721 /* Call into cpu_idle with preempt disabled */
722 cpu_startup_entry(CPUHP_ONLINE
);
725 /* Check for early params. */
726 static int __init
do_early_param(char *param
, char *val
,
727 const char *unused
, void *arg
)
729 const struct obs_kernel_param
*p
;
731 for (p
= __setup_start
; p
< __setup_end
; p
++) {
732 if ((p
->early
&& parameq(param
, p
->str
)) ||
733 (strcmp(param
, "console") == 0 &&
734 strcmp(p
->str
, "earlycon") == 0)
736 if (p
->setup_func(val
) != 0)
737 pr_warn("Malformed early option '%s'\n", param
);
740 /* We accept everything at this stage. */
744 void __init
parse_early_options(char *cmdline
)
746 parse_args("early options", cmdline
, NULL
, 0, 0, 0, NULL
,
750 /* Arch code calls this early on, or if not, just before other parsing. */
751 void __init
parse_early_param(void)
753 static int done __initdata
;
754 static char tmp_cmdline
[COMMAND_LINE_SIZE
] __initdata
;
759 /* All fall through to do_early_param. */
760 strlcpy(tmp_cmdline
, boot_command_line
, COMMAND_LINE_SIZE
);
761 parse_early_options(tmp_cmdline
);
765 void __init __weak
arch_post_acpi_subsys_init(void) { }
767 void __init __weak
smp_setup_processor_id(void)
771 # if THREAD_SIZE >= PAGE_SIZE
772 void __init __weak
thread_stack_cache_init(void)
777 void __init __weak
mem_encrypt_init(void) { }
779 void __init __weak
poking_init(void) { }
781 void __init __weak
pgtable_cache_init(void) { }
784 core_param(initcall_debug
, initcall_debug
, bool, 0644);
786 #ifdef TRACEPOINTS_ENABLED
787 static void __init
initcall_debug_enable(void);
789 static inline void initcall_debug_enable(void)
794 /* Report memory auto-initialization states for this boot. */
795 static void __init
report_meminit(void)
799 if (IS_ENABLED(CONFIG_INIT_STACK_ALL_PATTERN
))
800 stack
= "all(pattern)";
801 else if (IS_ENABLED(CONFIG_INIT_STACK_ALL_ZERO
))
803 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL
))
804 stack
= "byref_all(zero)";
805 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF
))
806 stack
= "byref(zero)";
807 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER
))
808 stack
= "__user(zero)";
812 pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n",
813 stack
, want_init_on_alloc(GFP_KERNEL
) ? "on" : "off",
814 want_init_on_free() ? "on" : "off");
815 if (want_init_on_free())
816 pr_info("mem auto-init: clearing system memory may take some time...\n");
820 * Set up kernel memory allocators
822 static void __init
mm_init(void)
825 * page_ext requires contiguous pages,
826 * bigger than MAX_ORDER unless SPARSEMEM.
828 page_ext_init_flatmem();
829 init_mem_debugging_and_hardening();
834 mem_init_print_info();
835 /* page_owner must be initialized after buddy is ready */
836 page_ext_init_flatmem_late();
840 debug_objects_mem_init();
842 /* Should be run before the first non-init thread is created */
844 /* Should be run after espfix64 is set up. */
848 #ifdef CONFIG_HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
849 DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT
,
850 randomize_kstack_offset
);
851 DEFINE_PER_CPU(u32
, kstack_offset
);
853 static int __init
early_randomize_kstack_offset(char *buf
)
858 ret
= kstrtobool(buf
, &bool_result
);
863 static_branch_enable(&randomize_kstack_offset
);
865 static_branch_disable(&randomize_kstack_offset
);
868 early_param("randomize_kstack_offset", early_randomize_kstack_offset
);
871 void __init __weak
arch_call_rest_init(void)
876 asmlinkage __visible
void __init __no_sanitize_address
start_kernel(void)
881 set_task_stack_end_magic(&init_task
);
882 smp_setup_processor_id();
883 debug_objects_early_init();
888 early_boot_irqs_disabled
= true;
891 * Interrupts are still disabled. Do necessary setups, then
896 pr_notice("%s", linux_banner
);
897 early_security_init();
898 setup_arch(&command_line
);
900 setup_command_line(command_line
);
902 setup_per_cpu_areas();
903 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
904 boot_cpu_hotplug_init();
906 build_all_zonelists(NULL
);
909 pr_notice("Kernel command line: %s\n", saved_command_line
);
910 /* parameters may set static keys */
913 after_dashes
= parse_args("Booting kernel",
914 static_command_line
, __start___param
,
915 __stop___param
- __start___param
,
916 -1, -1, NULL
, &unknown_bootoption
);
917 if (!IS_ERR_OR_NULL(after_dashes
))
918 parse_args("Setting init args", after_dashes
, NULL
, 0, -1, -1,
921 parse_args("Setting extra init args", extra_init_args
,
922 NULL
, 0, -1, -1, NULL
, set_init_arg
);
925 * These use large bootmem allocations and must precede
929 vfs_caches_init_early();
936 /* trace_printk can be enabled here */
940 * Set up the scheduler prior starting any interrupts (such as the
941 * timer interrupt). Full topology setup happens at smp_init()
942 * time - but meanwhile we still have a functioning scheduler.
946 if (WARN(!irqs_disabled(),
947 "Interrupts were enabled *very* early, fixing it\n"))
952 * Set up housekeeping before setting up workqueues to allow the unbound
953 * workqueue to take non-housekeeping into account.
958 * Allow workqueue creation and work item queueing/cancelling
959 * early. Work item execution depends on kthreads and starts after
962 workqueue_init_early();
966 /* Trace events are available after this */
970 initcall_debug_enable();
972 context_tracking_init();
973 /* init some links before init_ISA_irqs() */
985 * For best initial stack canary entropy, prepare it after:
986 * - setup_arch() for any UEFI RNG entropy and boot cmdline access
987 * - timekeeping_init() for ktime entropy used in rand_initialize()
988 * - rand_initialize() to get any arch-specific entropy like RDRAND
989 * - add_latent_entropy() to get any latent entropy
990 * - adding command line entropy
993 add_latent_entropy();
994 add_device_randomness(command_line
, strlen(command_line
));
995 boot_init_stack_canary();
1000 call_function_init();
1001 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
1003 early_boot_irqs_disabled
= false;
1006 kmem_cache_init_late();
1009 * HACK ALERT! This is early. We're enabling the console before
1010 * we've done PCI setups etc, and console_init() must be aware of
1011 * this. But we do want output early, in case something goes wrong.
1015 panic("Too many boot %s vars at `%s'", panic_later
,
1021 * Need to run this when irqs are enabled, because it wants
1022 * to self-test [hard/soft]-irqs on/off lock inversion bugs
1028 * This needs to be called before any devices perform DMA
1029 * operations that might use the SWIOTLB bounce buffers. It will
1030 * mark the bounce buffers as decrypted so that their usage will
1031 * not cause "plain-text" data to be decrypted when accessed.
1035 #ifdef CONFIG_BLK_DEV_INITRD
1036 if (initrd_start
&& !initrd_below_start_ok
&&
1037 page_to_pfn(virt_to_page((void *)initrd_start
)) < min_low_pfn
) {
1038 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
1039 page_to_pfn(virt_to_page((void *)initrd_start
)),
1044 setup_per_cpu_pageset();
1054 if (efi_enabled(EFI_RUNTIME_SERVICES
))
1055 efi_enter_virtual_mode();
1057 thread_stack_cache_init();
1073 taskstats_init_early();
1079 acpi_subsystem_init();
1080 arch_post_acpi_subsys_init();
1083 /* Do the rest non-__init'ed, we're now alive */
1084 arch_call_rest_init();
1086 prevent_tail_call_optimization();
1089 /* Call all constructor functions linked into the kernel. */
1090 static void __init
do_ctors(void)
1093 * For UML, the constructors have already been called by the
1094 * normal setup code as it's just a normal ELF binary, so we
1095 * cannot do it again - but we do need CONFIG_CONSTRUCTORS
1096 * even on UML for modules.
1098 #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML)
1099 ctor_fn_t
*fn
= (ctor_fn_t
*) __ctors_start
;
1101 for (; fn
< (ctor_fn_t
*) __ctors_end
; fn
++)
1106 #ifdef CONFIG_KALLSYMS
1107 struct blacklist_entry
{
1108 struct list_head next
;
1112 static __initdata_or_module
LIST_HEAD(blacklisted_initcalls
);
1114 static int __init
initcall_blacklist(char *str
)
1117 struct blacklist_entry
*entry
;
1119 /* str argument is a comma-separated list of functions */
1121 str_entry
= strsep(&str
, ",");
1123 pr_debug("blacklisting initcall %s\n", str_entry
);
1124 entry
= memblock_alloc(sizeof(*entry
),
1127 panic("%s: Failed to allocate %zu bytes\n",
1128 __func__
, sizeof(*entry
));
1129 entry
->buf
= memblock_alloc(strlen(str_entry
) + 1,
1132 panic("%s: Failed to allocate %zu bytes\n",
1133 __func__
, strlen(str_entry
) + 1);
1134 strcpy(entry
->buf
, str_entry
);
1135 list_add(&entry
->next
, &blacklisted_initcalls
);
1137 } while (str_entry
);
1142 static bool __init_or_module
initcall_blacklisted(initcall_t fn
)
1144 struct blacklist_entry
*entry
;
1145 char fn_name
[KSYM_SYMBOL_LEN
];
1148 if (list_empty(&blacklisted_initcalls
))
1151 addr
= (unsigned long) dereference_function_descriptor(fn
);
1152 sprint_symbol_no_offset(fn_name
, addr
);
1155 * fn will be "function_name [module_name]" where [module_name] is not
1156 * displayed for built-in init functions. Strip off the [module_name].
1158 strreplace(fn_name
, ' ', '\0');
1160 list_for_each_entry(entry
, &blacklisted_initcalls
, next
) {
1161 if (!strcmp(fn_name
, entry
->buf
)) {
1162 pr_debug("initcall %s blacklisted\n", fn_name
);
1170 static int __init
initcall_blacklist(char *str
)
1172 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
1176 static bool __init_or_module
initcall_blacklisted(initcall_t fn
)
1181 __setup("initcall_blacklist=", initcall_blacklist
);
1183 static __init_or_module
void
1184 trace_initcall_start_cb(void *data
, initcall_t fn
)
1186 ktime_t
*calltime
= (ktime_t
*)data
;
1188 printk(KERN_DEBUG
"calling %pS @ %i\n", fn
, task_pid_nr(current
));
1189 *calltime
= ktime_get();
1192 static __init_or_module
void
1193 trace_initcall_finish_cb(void *data
, initcall_t fn
, int ret
)
1195 ktime_t
*calltime
= (ktime_t
*)data
;
1196 ktime_t delta
, rettime
;
1197 unsigned long long duration
;
1199 rettime
= ktime_get();
1200 delta
= ktime_sub(rettime
, *calltime
);
1201 duration
= (unsigned long long) ktime_to_ns(delta
) >> 10;
1202 printk(KERN_DEBUG
"initcall %pS returned %d after %lld usecs\n",
1206 static ktime_t initcall_calltime
;
1208 #ifdef TRACEPOINTS_ENABLED
1209 static void __init
initcall_debug_enable(void)
1213 ret
= register_trace_initcall_start(trace_initcall_start_cb
,
1214 &initcall_calltime
);
1215 ret
|= register_trace_initcall_finish(trace_initcall_finish_cb
,
1216 &initcall_calltime
);
1217 WARN(ret
, "Failed to register initcall tracepoints\n");
1219 # define do_trace_initcall_start trace_initcall_start
1220 # define do_trace_initcall_finish trace_initcall_finish
1222 static inline void do_trace_initcall_start(initcall_t fn
)
1224 if (!initcall_debug
)
1226 trace_initcall_start_cb(&initcall_calltime
, fn
);
1228 static inline void do_trace_initcall_finish(initcall_t fn
, int ret
)
1230 if (!initcall_debug
)
1232 trace_initcall_finish_cb(&initcall_calltime
, fn
, ret
);
1234 #endif /* !TRACEPOINTS_ENABLED */
1236 int __init_or_module
do_one_initcall(initcall_t fn
)
1238 int count
= preempt_count();
1242 if (initcall_blacklisted(fn
))
1245 do_trace_initcall_start(fn
);
1247 do_trace_initcall_finish(fn
, ret
);
1251 if (preempt_count() != count
) {
1252 sprintf(msgbuf
, "preemption imbalance ");
1253 preempt_count_set(count
);
1255 if (irqs_disabled()) {
1256 strlcat(msgbuf
, "disabled interrupts ", sizeof(msgbuf
));
1259 WARN(msgbuf
[0], "initcall %pS returned with %s\n", fn
, msgbuf
);
1261 add_latent_entropy();
1266 extern initcall_entry_t __initcall_start
[];
1267 extern initcall_entry_t __initcall0_start
[];
1268 extern initcall_entry_t __initcall1_start
[];
1269 extern initcall_entry_t __initcall2_start
[];
1270 extern initcall_entry_t __initcall3_start
[];
1271 extern initcall_entry_t __initcall4_start
[];
1272 extern initcall_entry_t __initcall5_start
[];
1273 extern initcall_entry_t __initcall6_start
[];
1274 extern initcall_entry_t __initcall7_start
[];
1275 extern initcall_entry_t __initcall_end
[];
1277 static initcall_entry_t
*initcall_levels
[] __initdata
= {
1289 /* Keep these in sync with initcalls in include/linux/init.h */
1290 static const char *initcall_level_names
[] __initdata
= {
1301 static int __init
ignore_unknown_bootoption(char *param
, char *val
,
1302 const char *unused
, void *arg
)
1307 static void __init
do_initcall_level(int level
, char *command_line
)
1309 initcall_entry_t
*fn
;
1311 parse_args(initcall_level_names
[level
],
1312 command_line
, __start___param
,
1313 __stop___param
- __start___param
,
1315 NULL
, ignore_unknown_bootoption
);
1317 trace_initcall_level(initcall_level_names
[level
]);
1318 for (fn
= initcall_levels
[level
]; fn
< initcall_levels
[level
+1]; fn
++)
1319 do_one_initcall(initcall_from_entry(fn
));
1322 static void __init
do_initcalls(void)
1325 size_t len
= strlen(saved_command_line
) + 1;
1328 command_line
= kzalloc(len
, GFP_KERNEL
);
1330 panic("%s: Failed to allocate %zu bytes\n", __func__
, len
);
1332 for (level
= 0; level
< ARRAY_SIZE(initcall_levels
) - 1; level
++) {
1333 /* Parser modifies command_line, restore it each time */
1334 strcpy(command_line
, saved_command_line
);
1335 do_initcall_level(level
, command_line
);
1338 kfree(command_line
);
1342 * Ok, the machine is now initialized. None of the devices
1343 * have been touched yet, but the CPU subsystem is up and
1344 * running, and memory and process management works.
1346 * Now we can finally start doing some real work..
1348 static void __init
do_basic_setup(void)
1354 usermodehelper_enable();
1358 static void __init
do_pre_smp_initcalls(void)
1360 initcall_entry_t
*fn
;
1362 trace_initcall_level("early");
1363 for (fn
= __initcall_start
; fn
< __initcall0_start
; fn
++)
1364 do_one_initcall(initcall_from_entry(fn
));
1367 static int run_init_process(const char *init_filename
)
1369 const char *const *p
;
1371 argv_init
[0] = init_filename
;
1372 pr_info("Run %s as init process\n", init_filename
);
1373 pr_debug(" with arguments:\n");
1374 for (p
= argv_init
; *p
; p
++)
1375 pr_debug(" %s\n", *p
);
1376 pr_debug(" with environment:\n");
1377 for (p
= envp_init
; *p
; p
++)
1378 pr_debug(" %s\n", *p
);
1379 return kernel_execve(init_filename
, argv_init
, envp_init
);
1382 static int try_to_run_init_process(const char *init_filename
)
1386 ret
= run_init_process(init_filename
);
1388 if (ret
&& ret
!= -ENOENT
) {
1389 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1390 init_filename
, ret
);
1396 static noinline
void __init
kernel_init_freeable(void);
1398 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1399 bool rodata_enabled __ro_after_init
= true;
1400 static int __init
set_debug_rodata(char *str
)
1402 return strtobool(str
, &rodata_enabled
);
1404 __setup("rodata=", set_debug_rodata
);
1407 #ifdef CONFIG_STRICT_KERNEL_RWX
1408 static void mark_readonly(void)
1410 if (rodata_enabled
) {
1412 * load_module() results in W+X mappings, which are cleaned
1413 * up with call_rcu(). Let's make sure that queued work is
1414 * flushed so that we don't hit false positives looking for
1415 * insecure pages which are W+X.
1421 pr_info("Kernel memory protection disabled.\n");
1423 #elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)
1424 static inline void mark_readonly(void)
1426 pr_warn("Kernel memory protection not selected by kernel config.\n");
1429 static inline void mark_readonly(void)
1431 pr_warn("This architecture does not have kernel memory protection.\n");
1435 void __weak
free_initmem(void)
1437 free_initmem_default(POISON_FREE_INITMEM
);
1440 static int __ref
kernel_init(void *unused
)
1445 * Wait until kthreadd is all set-up.
1447 wait_for_completion(&kthreadd_done
);
1449 kernel_init_freeable();
1450 /* need to finish all async __init code before freeing the memory */
1451 async_synchronize_full();
1452 kprobe_free_init_mem();
1453 ftrace_free_init_mem();
1454 kgdb_free_init_mem();
1459 * Kernel mappings are now finalized - update the userspace page-table
1464 system_state
= SYSTEM_RUNNING
;
1465 numa_default_policy();
1467 rcu_end_inkernel_boot();
1471 if (ramdisk_execute_command
) {
1472 ret
= run_init_process(ramdisk_execute_command
);
1475 pr_err("Failed to execute %s (error %d)\n",
1476 ramdisk_execute_command
, ret
);
1480 * We try each of these until one succeeds.
1482 * The Bourne shell can be used instead of init if we are
1483 * trying to recover a really broken machine.
1485 if (execute_command
) {
1486 ret
= run_init_process(execute_command
);
1489 panic("Requested init %s failed (error %d).",
1490 execute_command
, ret
);
1493 if (CONFIG_DEFAULT_INIT
[0] != '\0') {
1494 ret
= run_init_process(CONFIG_DEFAULT_INIT
);
1496 pr_err("Default init %s failed (error %d)\n",
1497 CONFIG_DEFAULT_INIT
, ret
);
1502 if (!try_to_run_init_process("/sbin/init") ||
1503 !try_to_run_init_process("/etc/init") ||
1504 !try_to_run_init_process("/bin/init") ||
1505 !try_to_run_init_process("/bin/sh"))
1508 panic("No working init found. Try passing init= option to kernel. "
1509 "See Linux Documentation/admin-guide/init.rst for guidance.");
1512 /* Open /dev/console, for stdin/stdout/stderr, this should never fail */
1513 void __init
console_on_rootfs(void)
1515 struct file
*file
= filp_open("/dev/console", O_RDWR
, 0);
1518 pr_err("Warning: unable to open an initial console.\n");
1527 static noinline
void __init
kernel_init_freeable(void)
1529 /* Now the scheduler is fully set up and can do blocking allocations */
1530 gfp_allowed_mask
= __GFP_BITS_MASK
;
1533 * init can allocate pages on any node
1535 set_mems_allowed(node_states
[N_MEMORY
]);
1537 cad_pid
= get_pid(task_pid(current
));
1539 smp_prepare_cpus(setup_max_cpus
);
1543 init_mm_internals();
1545 rcu_init_tasks_generic();
1546 do_pre_smp_initcalls();
1547 lockup_detector_init();
1553 page_alloc_init_late();
1554 /* Initialize page ext after all struct pages are initialized. */
1559 kunit_run_all_tests();
1561 wait_for_initramfs();
1562 console_on_rootfs();
1565 * check if there is an early userspace init. If yes, let it do all
1568 if (init_eaccess(ramdisk_execute_command
) != 0) {
1569 ramdisk_execute_command
= NULL
;
1570 prepare_namespace();
1574 * Ok, we have completed the initial bootup, and
1575 * we're essentially up and running. Get rid of the
1576 * initmem segments and start the user-mode stuff..
1578 * rootfs is available now, try loading the public keys
1579 * and default modules
1582 integrity_load_keys();