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/vmalloc.h>
37 #include <linux/kernel_stat.h>
38 #include <linux/start_kernel.h>
39 #include <linux/security.h>
40 #include <linux/smp.h>
41 #include <linux/profile.h>
42 #include <linux/rcupdate.h>
43 #include <linux/moduleparam.h>
44 #include <linux/kallsyms.h>
45 #include <linux/writeback.h>
46 #include <linux/cpu.h>
47 #include <linux/cpuset.h>
48 #include <linux/cgroup.h>
49 #include <linux/efi.h>
50 #include <linux/tick.h>
51 #include <linux/sched/isolation.h>
52 #include <linux/interrupt.h>
53 #include <linux/taskstats_kern.h>
54 #include <linux/delayacct.h>
55 #include <linux/unistd.h>
56 #include <linux/utsname.h>
57 #include <linux/rmap.h>
58 #include <linux/mempolicy.h>
59 #include <linux/key.h>
60 #include <linux/buffer_head.h>
61 #include <linux/page_ext.h>
62 #include <linux/debug_locks.h>
63 #include <linux/debugobjects.h>
64 #include <linux/lockdep.h>
65 #include <linux/kmemleak.h>
66 #include <linux/padata.h>
67 #include <linux/pid_namespace.h>
68 #include <linux/device/driver.h>
69 #include <linux/kthread.h>
70 #include <linux/sched.h>
71 #include <linux/sched/init.h>
72 #include <linux/signal.h>
73 #include <linux/idr.h>
74 #include <linux/kgdb.h>
75 #include <linux/ftrace.h>
76 #include <linux/async.h>
77 #include <linux/sfi.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>
100 #include <asm/bugs.h>
101 #include <asm/setup.h>
102 #include <asm/sections.h>
103 #include <asm/cacheflush.h>
105 #define CREATE_TRACE_POINTS
106 #include <trace/events/initcall.h>
108 static int kernel_init(void *);
110 extern void init_IRQ(void);
111 extern void radix_tree_init(void);
114 * Debug helper: via this flag we know that we are in 'early bootup code'
115 * where only the boot processor is running with IRQ disabled. This means
116 * two things - IRQ must not be enabled before the flag is cleared and some
117 * operations which are not allowed with IRQ disabled are allowed while the
120 bool early_boot_irqs_disabled __read_mostly;
122 enum system_states system_state __read_mostly;
123 EXPORT_SYMBOL(system_state);
126 * Boot command-line arguments
128 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
129 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
131 extern void time_init(void);
132 /* Default late time init is NULL. archs can override this later. */
133 void (*__initdata late_time_init)(void);
135 /* Untouched command line saved by arch-specific code. */
136 char __initdata boot_command_line[COMMAND_LINE_SIZE];
137 /* Untouched saved command line (eg. for /proc) */
138 char *saved_command_line;
139 /* Command line for parameter parsing */
140 static char *static_command_line;
141 /* Untouched extra command line */
142 static char *extra_command_line;
143 /* Extra init arguments */
144 static char *extra_init_args;
146 #ifdef CONFIG_BOOT_CONFIG
147 /* Is bootconfig on command line? */
148 static bool bootconfig_found;
149 static bool initargs_found;
151 # define bootconfig_found false
152 # define initargs_found false
155 static char *execute_command;
156 static char *ramdisk_execute_command;
159 * Used to generate warnings if static_key manipulation functions are used
160 * before jump_label_init is called.
162 bool static_key_initialized __read_mostly;
163 EXPORT_SYMBOL_GPL(static_key_initialized);
166 * If set, this is an indication to the drivers that reset the underlying
167 * device before going ahead with the initialization otherwise driver might
168 * rely on the BIOS and skip the reset operation.
170 * This is useful if kernel is booting in an unreliable environment.
171 * For ex. kdump situation where previous kernel has crashed, BIOS has been
172 * skipped and devices will be in unknown state.
174 unsigned int reset_devices;
175 EXPORT_SYMBOL(reset_devices);
177 static int __init set_reset_devices(char *str)
183 __setup("reset_devices", set_reset_devices);
185 static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
186 const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
187 static const char *panic_later, *panic_param;
189 extern const struct obs_kernel_param __setup_start[], __setup_end[];
191 static bool __init obsolete_checksetup(char *line)
193 const struct obs_kernel_param *p;
194 bool had_early_param = false;
198 int n = strlen(p->str);
199 if (parameqn(line, p->str, n)) {
201 /* Already done in parse_early_param?
202 * (Needs exact match on param part).
203 * Keep iterating, as we can have early
204 * params and __setups of same names 8( */
205 if (line[n] == '\0' || line[n] == '=')
206 had_early_param = true;
207 } else if (!p->setup_func) {
208 pr_warn("Parameter %s is obsolete, ignored\n",
211 } else if (p->setup_func(line + n))
215 } while (p < __setup_end);
217 return had_early_param;
221 * This should be approx 2 Bo*oMips to start (note initial shift), and will
222 * still work even if initially too large, it will just take slightly longer
224 unsigned long loops_per_jiffy = (1<<12);
225 EXPORT_SYMBOL(loops_per_jiffy);
227 static int __init debug_kernel(char *str)
229 console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
233 static int __init quiet_kernel(char *str)
235 console_loglevel = CONSOLE_LOGLEVEL_QUIET;
239 early_param("debug", debug_kernel);
240 early_param("quiet", quiet_kernel);
242 static int __init loglevel(char *str)
247 * Only update loglevel value when a correct setting was passed,
248 * to prevent blind crashes (when loglevel being set to 0) that
249 * are quite hard to debug
251 if (get_option(&str, &newlevel)) {
252 console_loglevel = newlevel;
259 early_param("loglevel", loglevel);
261 #ifdef CONFIG_BLK_DEV_INITRD
262 static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum)
271 data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
272 if (memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
275 hdr = (u32 *)(data - 8);
279 data = ((void *)hdr) - size;
280 if ((unsigned long)data < initrd_start) {
281 pr_err("bootconfig size %d is greater than initrd size %ld\n",
282 size, initrd_end - initrd_start);
286 /* Remove bootconfig from initramfs/initrd */
287 initrd_end = (unsigned long)data;
296 static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum)
302 #ifdef CONFIG_BOOT_CONFIG
304 char xbc_namebuf[XBC_KEYLEN_MAX] __initdata;
306 #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
308 static int __init xbc_snprint_cmdline(char *buf, size_t size,
309 struct xbc_node *root)
311 struct xbc_node *knode, *vnode;
312 char *end = buf + size;
316 xbc_node_for_each_key_value(root, knode, val) {
317 ret = xbc_node_compose_key_after(root, knode,
318 xbc_namebuf, XBC_KEYLEN_MAX);
322 vnode = xbc_node_get_child(knode);
324 ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf);
330 xbc_array_for_each_value(vnode, val) {
331 ret = snprintf(buf, rest(buf, end), "%s=\"%s\" ",
339 return buf - (end - size);
343 /* Make an extra command line under given key word */
344 static char * __init xbc_make_cmdline(const char *key)
346 struct xbc_node *root;
350 root = xbc_find_node(key);
354 /* Count required buffer size */
355 len = xbc_snprint_cmdline(NULL, 0, root);
359 new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES);
361 pr_err("Failed to allocate memory for extra kernel cmdline.\n");
365 ret = xbc_snprint_cmdline(new_cmdline, len + 1, root);
366 if (ret < 0 || ret > len) {
367 pr_err("Failed to print extra kernel cmdline.\n");
374 static u32 boot_config_checksum(unsigned char *p, u32 size)
384 static int __init bootconfig_params(char *param, char *val,
385 const char *unused, void *arg)
387 if (strcmp(param, "bootconfig") == 0) {
388 bootconfig_found = true;
389 } else if (strcmp(param, "--") == 0) {
390 initargs_found = true;
395 static void __init setup_boot_config(const char *cmdline)
397 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
404 /* Cut out the bootconfig data even if we have no bootconfig option */
405 data = get_boot_config_from_initrd(&size, &csum);
407 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
408 parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
411 if (!bootconfig_found)
415 pr_err("'bootconfig' found on command line, but no bootconfig found\n");
419 if (size >= XBC_DATA_MAX) {
420 pr_err("bootconfig size %d greater than max size %d\n",
425 if (boot_config_checksum((unsigned char *)data, size) != csum) {
426 pr_err("bootconfig checksum failed\n");
430 copy = memblock_alloc(size + 1, SMP_CACHE_BYTES);
432 pr_err("Failed to allocate memory for bootconfig\n");
436 memcpy(copy, data, size);
439 ret = xbc_init(copy, &msg, &pos);
442 pr_err("Failed to init bootconfig: %s.\n", msg);
444 pr_err("Failed to parse bootconfig: %s at %d.\n",
447 pr_info("Load bootconfig: %d bytes %d nodes\n", size, ret);
448 /* keys starting with "kernel." are passed via cmdline */
449 extra_command_line = xbc_make_cmdline("kernel");
450 /* Also, "init." keys are init arguments */
451 extra_init_args = xbc_make_cmdline("init");
458 static void __init setup_boot_config(const char *cmdline)
460 /* Remove bootconfig data from initrd */
461 get_boot_config_from_initrd(NULL, NULL);
464 static int __init warn_bootconfig(char *str)
466 pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOTCONFIG is not set.\n");
469 early_param("bootconfig", warn_bootconfig);
473 /* Change NUL term back to "=", to make "param" the whole string. */
474 static void __init repair_env_string(char *param, char *val)
477 /* param=val or param="val"? */
478 if (val == param+strlen(param)+1)
480 else if (val == param+strlen(param)+2) {
482 memmove(val-1, val, strlen(val)+1);
488 /* Anything after -- gets handed straight to init. */
489 static int __init set_init_arg(char *param, char *val,
490 const char *unused, void *arg)
497 repair_env_string(param, val);
499 for (i = 0; argv_init[i]; i++) {
500 if (i == MAX_INIT_ARGS) {
501 panic_later = "init";
506 argv_init[i] = param;
511 * Unknown boot options get handed to init, unless they look like
512 * unused parameters (modprobe will find them in /proc/cmdline).
514 static int __init unknown_bootoption(char *param, char *val,
515 const char *unused, void *arg)
517 size_t len = strlen(param);
519 repair_env_string(param, val);
521 /* Handle obsolete-style parameters */
522 if (obsolete_checksetup(param))
525 /* Unused module parameter. */
526 if (strnchr(param, len, '.'))
533 /* Environment option */
535 for (i = 0; envp_init[i]; i++) {
536 if (i == MAX_INIT_ENVS) {
540 if (!strncmp(param, envp_init[i], len+1))
543 envp_init[i] = param;
545 /* Command line option */
547 for (i = 0; argv_init[i]; i++) {
548 if (i == MAX_INIT_ARGS) {
549 panic_later = "init";
553 argv_init[i] = param;
558 static int __init init_setup(char *str)
562 execute_command = str;
564 * In case LILO is going to boot us with default command line,
565 * it prepends "auto" before the whole cmdline which makes
566 * the shell think it should execute a script with such name.
567 * So we ignore all arguments entered _before_ init=... [MJ]
569 for (i = 1; i < MAX_INIT_ARGS; i++)
573 __setup("init=", init_setup);
575 static int __init rdinit_setup(char *str)
579 ramdisk_execute_command = str;
580 /* See "auto" comment in init_setup */
581 for (i = 1; i < MAX_INIT_ARGS; i++)
585 __setup("rdinit=", rdinit_setup);
588 static const unsigned int setup_max_cpus = NR_CPUS;
589 static inline void setup_nr_cpu_ids(void) { }
590 static inline void smp_prepare_cpus(unsigned int maxcpus) { }
594 * We need to store the untouched command line for future reference.
595 * We also need to store the touched command line since the parameter
596 * parsing is performed in place, and we should allow a component to
597 * store reference of name/value for future reference.
599 static void __init setup_command_line(char *command_line)
601 size_t len, xlen = 0, ilen = 0;
603 if (extra_command_line)
604 xlen = strlen(extra_command_line);
606 ilen = strlen(extra_init_args) + 4; /* for " -- " */
608 len = xlen + strlen(boot_command_line) + 1;
610 saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES);
611 if (!saved_command_line)
612 panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen);
614 static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
615 if (!static_command_line)
616 panic("%s: Failed to allocate %zu bytes\n", __func__, len);
620 * We have to put extra_command_line before boot command
621 * lines because there could be dashes (separator of init
622 * command line) in the command lines.
624 strcpy(saved_command_line, extra_command_line);
625 strcpy(static_command_line, extra_command_line);
627 strcpy(saved_command_line + xlen, boot_command_line);
628 strcpy(static_command_line + xlen, command_line);
632 * Append supplemental init boot args to saved_command_line
633 * so that user can check what command line options passed
636 len = strlen(saved_command_line);
637 if (initargs_found) {
638 saved_command_line[len++] = ' ';
640 strcpy(saved_command_line + len, " -- ");
644 strcpy(saved_command_line + len, extra_init_args);
649 * We need to finalize in a non-__init function or else race conditions
650 * between the root thread and the init thread may cause start_kernel to
651 * be reaped by free_initmem before the root thread has proceeded to
654 * gcc-3.4 accidentally inlines this function, so use noinline.
657 static __initdata DECLARE_COMPLETION(kthreadd_done);
659 noinline void __ref rest_init(void)
661 struct task_struct *tsk;
664 rcu_scheduler_starting();
666 * We need to spawn init first so that it obtains pid 1, however
667 * the init task will end up wanting to create kthreads, which, if
668 * we schedule it before we create kthreadd, will OOPS.
670 pid = kernel_thread(kernel_init, NULL, CLONE_FS);
672 * Pin init on the boot CPU. Task migration is not properly working
673 * until sched_init_smp() has been run. It will set the allowed
674 * CPUs for init to the non isolated CPUs.
677 tsk = find_task_by_pid_ns(pid, &init_pid_ns);
678 set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
681 numa_default_policy();
682 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
684 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
688 * Enable might_sleep() and smp_processor_id() checks.
689 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
690 * kernel_thread() would trigger might_sleep() splats. With
691 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
692 * already, but it's stuck on the kthreadd_done completion.
694 system_state = SYSTEM_SCHEDULING;
696 complete(&kthreadd_done);
699 * The boot idle thread must execute schedule()
700 * at least once to get things moving:
702 schedule_preempt_disabled();
703 /* Call into cpu_idle with preempt disabled */
704 cpu_startup_entry(CPUHP_ONLINE);
707 /* Check for early params. */
708 static int __init do_early_param(char *param, char *val,
709 const char *unused, void *arg)
711 const struct obs_kernel_param *p;
713 for (p = __setup_start; p < __setup_end; p++) {
714 if ((p->early && parameq(param, p->str)) ||
715 (strcmp(param, "console") == 0 &&
716 strcmp(p->str, "earlycon") == 0)
718 if (p->setup_func(val) != 0)
719 pr_warn("Malformed early option '%s'\n", param);
722 /* We accept everything at this stage. */
726 void __init parse_early_options(char *cmdline)
728 parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
732 /* Arch code calls this early on, or if not, just before other parsing. */
733 void __init parse_early_param(void)
735 static int done __initdata;
736 static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
741 /* All fall through to do_early_param. */
742 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
743 parse_early_options(tmp_cmdline);
747 void __init __weak arch_post_acpi_subsys_init(void) { }
749 void __init __weak smp_setup_processor_id(void)
753 # if THREAD_SIZE >= PAGE_SIZE
754 void __init __weak thread_stack_cache_init(void)
759 void __init __weak mem_encrypt_init(void) { }
761 void __init __weak poking_init(void) { }
763 void __init __weak pgtable_cache_init(void) { }
766 core_param(initcall_debug, initcall_debug, bool, 0644);
768 #ifdef TRACEPOINTS_ENABLED
769 static void __init initcall_debug_enable(void);
771 static inline void initcall_debug_enable(void)
776 /* Report memory auto-initialization states for this boot. */
777 static void __init report_meminit(void)
781 if (IS_ENABLED(CONFIG_INIT_STACK_ALL))
783 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL))
785 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF))
787 else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER))
792 pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n",
793 stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off",
794 want_init_on_free() ? "on" : "off");
795 if (want_init_on_free())
796 pr_info("mem auto-init: clearing system memory may take some time...\n");
800 * Set up kernel memory allocators
802 static void __init mm_init(void)
805 * page_ext requires contiguous pages,
806 * bigger than MAX_ORDER unless SPARSEMEM.
808 page_ext_init_flatmem();
809 init_debug_pagealloc();
815 debug_objects_mem_init();
818 /* Should be run before the first non-init thread is created */
820 /* Should be run after espfix64 is set up. */
824 void __init __weak arch_call_rest_init(void)
829 asmlinkage __visible void __init start_kernel(void)
834 set_task_stack_end_magic(&init_task);
835 smp_setup_processor_id();
836 debug_objects_early_init();
841 early_boot_irqs_disabled = true;
844 * Interrupts are still disabled. Do necessary setups, then
849 pr_notice("%s", linux_banner);
850 early_security_init();
851 setup_arch(&command_line);
852 setup_boot_config(command_line);
853 setup_command_line(command_line);
855 setup_per_cpu_areas();
856 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
857 boot_cpu_hotplug_init();
859 build_all_zonelists(NULL);
862 pr_notice("Kernel command line: %s\n", saved_command_line);
863 /* parameters may set static keys */
866 after_dashes = parse_args("Booting kernel",
867 static_command_line, __start___param,
868 __stop___param - __start___param,
869 -1, -1, NULL, &unknown_bootoption);
870 if (!IS_ERR_OR_NULL(after_dashes))
871 parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
874 parse_args("Setting extra init args", extra_init_args,
875 NULL, 0, -1, -1, NULL, set_init_arg);
878 * These use large bootmem allocations and must precede
882 vfs_caches_init_early();
889 /* trace_printk can be enabled here */
893 * Set up the scheduler prior starting any interrupts (such as the
894 * timer interrupt). Full topology setup happens at smp_init()
895 * time - but meanwhile we still have a functioning scheduler.
899 * Disable preemption - early bootup scheduling is extremely
900 * fragile until we cpu_idle() for the first time.
903 if (WARN(!irqs_disabled(),
904 "Interrupts were enabled *very* early, fixing it\n"))
909 * Set up housekeeping before setting up workqueues to allow the unbound
910 * workqueue to take non-housekeeping into account.
915 * Allow workqueue creation and work item queueing/cancelling
916 * early. Work item execution depends on kthreads and starts after
919 workqueue_init_early();
923 /* Trace events are available after this */
927 initcall_debug_enable();
929 context_tracking_init();
930 /* init some links before init_ISA_irqs() */
941 * For best initial stack canary entropy, prepare it after:
942 * - setup_arch() for any UEFI RNG entropy and boot cmdline access
943 * - timekeeping_init() for ktime entropy used in rand_initialize()
944 * - rand_initialize() to get any arch-specific entropy like RDRAND
945 * - add_latent_entropy() to get any latent entropy
946 * - adding command line entropy
949 add_latent_entropy();
950 add_device_randomness(command_line, strlen(command_line));
951 boot_init_stack_canary();
956 call_function_init();
957 WARN(!irqs_disabled(), "Interrupts were enabled early\n");
959 early_boot_irqs_disabled = false;
962 kmem_cache_init_late();
965 * HACK ALERT! This is early. We're enabling the console before
966 * we've done PCI setups etc, and console_init() must be aware of
967 * this. But we do want output early, in case something goes wrong.
971 panic("Too many boot %s vars at `%s'", panic_later,
977 * Need to run this when irqs are enabled, because it wants
978 * to self-test [hard/soft]-irqs on/off lock inversion bugs
984 * This needs to be called before any devices perform DMA
985 * operations that might use the SWIOTLB bounce buffers. It will
986 * mark the bounce buffers as decrypted so that their usage will
987 * not cause "plain-text" data to be decrypted when accessed.
991 #ifdef CONFIG_BLK_DEV_INITRD
992 if (initrd_start && !initrd_below_start_ok &&
993 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
994 pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
995 page_to_pfn(virt_to_page((void *)initrd_start)),
1000 setup_per_cpu_pageset();
1010 if (efi_enabled(EFI_RUNTIME_SERVICES))
1011 efi_enter_virtual_mode();
1013 thread_stack_cache_init();
1030 taskstats_init_early();
1036 acpi_subsystem_init();
1037 arch_post_acpi_subsys_init();
1040 /* Do the rest non-__init'ed, we're now alive */
1041 arch_call_rest_init();
1043 prevent_tail_call_optimization();
1046 /* Call all constructor functions linked into the kernel. */
1047 static void __init do_ctors(void)
1049 #ifdef CONFIG_CONSTRUCTORS
1050 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
1052 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
1057 #ifdef CONFIG_KALLSYMS
1058 struct blacklist_entry {
1059 struct list_head next;
1063 static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
1065 static int __init initcall_blacklist(char *str)
1068 struct blacklist_entry *entry;
1070 /* str argument is a comma-separated list of functions */
1072 str_entry = strsep(&str, ",");
1074 pr_debug("blacklisting initcall %s\n", str_entry);
1075 entry = memblock_alloc(sizeof(*entry),
1078 panic("%s: Failed to allocate %zu bytes\n",
1079 __func__, sizeof(*entry));
1080 entry->buf = memblock_alloc(strlen(str_entry) + 1,
1083 panic("%s: Failed to allocate %zu bytes\n",
1084 __func__, strlen(str_entry) + 1);
1085 strcpy(entry->buf, str_entry);
1086 list_add(&entry->next, &blacklisted_initcalls);
1088 } while (str_entry);
1093 static bool __init_or_module initcall_blacklisted(initcall_t fn)
1095 struct blacklist_entry *entry;
1096 char fn_name[KSYM_SYMBOL_LEN];
1099 if (list_empty(&blacklisted_initcalls))
1102 addr = (unsigned long) dereference_function_descriptor(fn);
1103 sprint_symbol_no_offset(fn_name, addr);
1106 * fn will be "function_name [module_name]" where [module_name] is not
1107 * displayed for built-in init functions. Strip off the [module_name].
1109 strreplace(fn_name, ' ', '\0');
1111 list_for_each_entry(entry, &blacklisted_initcalls, next) {
1112 if (!strcmp(fn_name, entry->buf)) {
1113 pr_debug("initcall %s blacklisted\n", fn_name);
1121 static int __init initcall_blacklist(char *str)
1123 pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
1127 static bool __init_or_module initcall_blacklisted(initcall_t fn)
1132 __setup("initcall_blacklist=", initcall_blacklist);
1134 static __init_or_module void
1135 trace_initcall_start_cb(void *data, initcall_t fn)
1137 ktime_t *calltime = (ktime_t *)data;
1139 printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current));
1140 *calltime = ktime_get();
1143 static __init_or_module void
1144 trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
1146 ktime_t *calltime = (ktime_t *)data;
1147 ktime_t delta, rettime;
1148 unsigned long long duration;
1150 rettime = ktime_get();
1151 delta = ktime_sub(rettime, *calltime);
1152 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
1153 printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
1157 static ktime_t initcall_calltime;
1159 #ifdef TRACEPOINTS_ENABLED
1160 static void __init initcall_debug_enable(void)
1164 ret = register_trace_initcall_start(trace_initcall_start_cb,
1165 &initcall_calltime);
1166 ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
1167 &initcall_calltime);
1168 WARN(ret, "Failed to register initcall tracepoints\n");
1170 # define do_trace_initcall_start trace_initcall_start
1171 # define do_trace_initcall_finish trace_initcall_finish
1173 static inline void do_trace_initcall_start(initcall_t fn)
1175 if (!initcall_debug)
1177 trace_initcall_start_cb(&initcall_calltime, fn);
1179 static inline void do_trace_initcall_finish(initcall_t fn, int ret)
1181 if (!initcall_debug)
1183 trace_initcall_finish_cb(&initcall_calltime, fn, ret);
1185 #endif /* !TRACEPOINTS_ENABLED */
1187 int __init_or_module do_one_initcall(initcall_t fn)
1189 int count = preempt_count();
1193 if (initcall_blacklisted(fn))
1196 do_trace_initcall_start(fn);
1198 do_trace_initcall_finish(fn, ret);
1202 if (preempt_count() != count) {
1203 sprintf(msgbuf, "preemption imbalance ");
1204 preempt_count_set(count);
1206 if (irqs_disabled()) {
1207 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
1210 WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
1212 add_latent_entropy();
1217 extern initcall_entry_t __initcall_start[];
1218 extern initcall_entry_t __initcall0_start[];
1219 extern initcall_entry_t __initcall1_start[];
1220 extern initcall_entry_t __initcall2_start[];
1221 extern initcall_entry_t __initcall3_start[];
1222 extern initcall_entry_t __initcall4_start[];
1223 extern initcall_entry_t __initcall5_start[];
1224 extern initcall_entry_t __initcall6_start[];
1225 extern initcall_entry_t __initcall7_start[];
1226 extern initcall_entry_t __initcall_end[];
1228 static initcall_entry_t *initcall_levels[] __initdata = {
1240 /* Keep these in sync with initcalls in include/linux/init.h */
1241 static const char *initcall_level_names[] __initdata = {
1252 static int __init ignore_unknown_bootoption(char *param, char *val,
1253 const char *unused, void *arg)
1258 static void __init do_initcall_level(int level, char *command_line)
1260 initcall_entry_t *fn;
1262 parse_args(initcall_level_names[level],
1263 command_line, __start___param,
1264 __stop___param - __start___param,
1266 NULL, ignore_unknown_bootoption);
1268 trace_initcall_level(initcall_level_names[level]);
1269 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
1270 do_one_initcall(initcall_from_entry(fn));
1273 static void __init do_initcalls(void)
1276 size_t len = strlen(saved_command_line) + 1;
1279 command_line = kzalloc(len, GFP_KERNEL);
1281 panic("%s: Failed to allocate %zu bytes\n", __func__, len);
1283 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
1284 /* Parser modifies command_line, restore it each time */
1285 strcpy(command_line, saved_command_line);
1286 do_initcall_level(level, command_line);
1289 kfree(command_line);
1293 * Ok, the machine is now initialized. None of the devices
1294 * have been touched yet, but the CPU subsystem is up and
1295 * running, and memory and process management works.
1297 * Now we can finally start doing some real work..
1299 static void __init do_basic_setup(void)
1305 usermodehelper_enable();
1309 static void __init do_pre_smp_initcalls(void)
1311 initcall_entry_t *fn;
1313 trace_initcall_level("early");
1314 for (fn = __initcall_start; fn < __initcall0_start; fn++)
1315 do_one_initcall(initcall_from_entry(fn));
1318 static int run_init_process(const char *init_filename)
1320 const char *const *p;
1322 argv_init[0] = init_filename;
1323 pr_info("Run %s as init process\n", init_filename);
1324 pr_debug(" with arguments:\n");
1325 for (p = argv_init; *p; p++)
1326 pr_debug(" %s\n", *p);
1327 pr_debug(" with environment:\n");
1328 for (p = envp_init; *p; p++)
1329 pr_debug(" %s\n", *p);
1330 return do_execve(getname_kernel(init_filename),
1331 (const char __user *const __user *)argv_init,
1332 (const char __user *const __user *)envp_init);
1335 static int try_to_run_init_process(const char *init_filename)
1339 ret = run_init_process(init_filename);
1341 if (ret && ret != -ENOENT) {
1342 pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1343 init_filename, ret);
1349 static noinline void __init kernel_init_freeable(void);
1351 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1352 bool rodata_enabled __ro_after_init = true;
1353 static int __init set_debug_rodata(char *str)
1355 return strtobool(str, &rodata_enabled);
1357 __setup("rodata=", set_debug_rodata);
1360 #ifdef CONFIG_STRICT_KERNEL_RWX
1361 static void mark_readonly(void)
1363 if (rodata_enabled) {
1365 * load_module() results in W+X mappings, which are cleaned
1366 * up with call_rcu(). Let's make sure that queued work is
1367 * flushed so that we don't hit false positives looking for
1368 * insecure pages which are W+X.
1374 pr_info("Kernel memory protection disabled.\n");
1376 #elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)
1377 static inline void mark_readonly(void)
1379 pr_warn("Kernel memory protection not selected by kernel config.\n");
1382 static inline void mark_readonly(void)
1384 pr_warn("This architecture does not have kernel memory protection.\n");
1388 void __weak free_initmem(void)
1390 free_initmem_default(POISON_FREE_INITMEM);
1393 static int __ref kernel_init(void *unused)
1397 kernel_init_freeable();
1398 /* need to finish all async __init code before freeing the memory */
1399 async_synchronize_full();
1400 ftrace_free_init_mem();
1405 * Kernel mappings are now finalized - update the userspace page-table
1410 system_state = SYSTEM_RUNNING;
1411 numa_default_policy();
1413 rcu_end_inkernel_boot();
1417 if (ramdisk_execute_command) {
1418 ret = run_init_process(ramdisk_execute_command);
1421 pr_err("Failed to execute %s (error %d)\n",
1422 ramdisk_execute_command, ret);
1426 * We try each of these until one succeeds.
1428 * The Bourne shell can be used instead of init if we are
1429 * trying to recover a really broken machine.
1431 if (execute_command) {
1432 ret = run_init_process(execute_command);
1435 panic("Requested init %s failed (error %d).",
1436 execute_command, ret);
1439 if (CONFIG_DEFAULT_INIT[0] != '\0') {
1440 ret = run_init_process(CONFIG_DEFAULT_INIT);
1442 pr_err("Default init %s failed (error %d)\n",
1443 CONFIG_DEFAULT_INIT, ret);
1448 if (!try_to_run_init_process("/sbin/init") ||
1449 !try_to_run_init_process("/etc/init") ||
1450 !try_to_run_init_process("/bin/init") ||
1451 !try_to_run_init_process("/bin/sh"))
1454 panic("No working init found. Try passing init= option to kernel. "
1455 "See Linux Documentation/admin-guide/init.rst for guidance.");
1458 void console_on_rootfs(void)
1460 /* Open the /dev/console as stdin, this should never fail */
1461 if (ksys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
1462 pr_err("Warning: unable to open an initial console.\n");
1464 /* create stdout/stderr */
1469 static noinline void __init kernel_init_freeable(void)
1472 * Wait until kthreadd is all set-up.
1474 wait_for_completion(&kthreadd_done);
1476 /* Now the scheduler is fully set up and can do blocking allocations */
1477 gfp_allowed_mask = __GFP_BITS_MASK;
1480 * init can allocate pages on any node
1482 set_mems_allowed(node_states[N_MEMORY]);
1484 cad_pid = task_pid(current);
1486 smp_prepare_cpus(setup_max_cpus);
1490 init_mm_internals();
1492 do_pre_smp_initcalls();
1493 lockup_detector_init();
1499 page_alloc_init_late();
1500 /* Initialize page ext after all struct pages are initialized. */
1505 console_on_rootfs();
1508 * check if there is an early userspace init. If yes, let it do all
1512 if (!ramdisk_execute_command)
1513 ramdisk_execute_command = "/init";
1515 if (ksys_access((const char __user *)
1516 ramdisk_execute_command, 0) != 0) {
1517 ramdisk_execute_command = NULL;
1518 prepare_namespace();
1522 * Ok, we have completed the initial bootup, and
1523 * we're essentially up and running. Get rid of the
1524 * initmem segments and start the user-mode stuff..
1526 * rootfs is available now, try loading the public keys
1527 * and default modules
1530 integrity_load_keys();