// SPDX-License-Identifier: GPL-2.0-only /* * linux/init/main.c * * Copyright (C) 1991, 1992 Linus Torvalds * * GK 2/5/95 - Changed to support mounting root fs via NFS * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96 * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96 * Simplified starting of init: Michael A. Griffith */ #define DEBUG /* Enable initcall_debug */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define CREATE_TRACE_POINTS #include #include static int kernel_init(void *); extern void init_IRQ(void); extern void radix_tree_init(void); /* * Debug helper: via this flag we know that we are in 'early bootup code' * where only the boot processor is running with IRQ disabled. This means * two things - IRQ must not be enabled before the flag is cleared and some * operations which are not allowed with IRQ disabled are allowed while the * flag is set. */ bool early_boot_irqs_disabled __read_mostly; enum system_states system_state __read_mostly; EXPORT_SYMBOL(system_state); /* * Boot command-line arguments */ #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT extern void time_init(void); /* Default late time init is NULL. archs can override this later. */ void (*__initdata late_time_init)(void); /* Untouched command line saved by arch-specific code. */ char __initdata boot_command_line[COMMAND_LINE_SIZE]; /* Untouched saved command line (eg. for /proc) */ char *saved_command_line; /* Command line for parameter parsing */ static char *static_command_line; /* Untouched extra command line */ static char *extra_command_line; /* Extra init arguments */ static char *extra_init_args; #ifdef CONFIG_BOOT_CONFIG /* Is bootconfig on command line? */ static bool bootconfig_found; static bool initargs_found; #else # define bootconfig_found false # define initargs_found false #endif static char *execute_command; static char *ramdisk_execute_command = "/init"; /* * Used to generate warnings if static_key manipulation functions are used * before jump_label_init is called. */ bool static_key_initialized __read_mostly; EXPORT_SYMBOL_GPL(static_key_initialized); /* * If set, this is an indication to the drivers that reset the underlying * device before going ahead with the initialization otherwise driver might * rely on the BIOS and skip the reset operation. * * This is useful if kernel is booting in an unreliable environment. * For ex. kdump situation where previous kernel has crashed, BIOS has been * skipped and devices will be in unknown state. */ unsigned int reset_devices; EXPORT_SYMBOL(reset_devices); static int __init set_reset_devices(char *str) { reset_devices = 1; return 1; } __setup("reset_devices", set_reset_devices); static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; static const char *panic_later, *panic_param; extern const struct obs_kernel_param __setup_start[], __setup_end[]; static bool __init obsolete_checksetup(char *line) { const struct obs_kernel_param *p; bool had_early_param = false; p = __setup_start; do { int n = strlen(p->str); if (parameqn(line, p->str, n)) { if (p->early) { /* Already done in parse_early_param? * (Needs exact match on param part). * Keep iterating, as we can have early * params and __setups of same names 8( */ if (line[n] == '\0' || line[n] == '=') had_early_param = true; } else if (!p->setup_func) { pr_warn("Parameter %s is obsolete, ignored\n", p->str); return true; } else if (p->setup_func(line + n)) return true; } p++; } while (p < __setup_end); return had_early_param; } /* * This should be approx 2 Bo*oMips to start (note initial shift), and will * still work even if initially too large, it will just take slightly longer */ unsigned long loops_per_jiffy = (1<<12); EXPORT_SYMBOL(loops_per_jiffy); static int __init debug_kernel(char *str) { console_loglevel = CONSOLE_LOGLEVEL_DEBUG; return 0; } static int __init quiet_kernel(char *str) { console_loglevel = CONSOLE_LOGLEVEL_QUIET; return 0; } early_param("debug", debug_kernel); early_param("quiet", quiet_kernel); static int __init loglevel(char *str) { int newlevel; /* * Only update loglevel value when a correct setting was passed, * to prevent blind crashes (when loglevel being set to 0) that * are quite hard to debug */ if (get_option(&str, &newlevel)) { console_loglevel = newlevel; return 0; } return -EINVAL; } early_param("loglevel", loglevel); #ifdef CONFIG_BLK_DEV_INITRD static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum) { u32 size, csum; char *data; u32 *hdr; int i; if (!initrd_end) return NULL; data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN; /* * Since Grub may align the size of initrd to 4, we must * check the preceding 3 bytes as well. */ for (i = 0; i < 4; i++) { if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN)) goto found; data--; } return NULL; found: hdr = (u32 *)(data - 8); size = le32_to_cpu(hdr[0]); csum = le32_to_cpu(hdr[1]); data = ((void *)hdr) - size; if ((unsigned long)data < initrd_start) { pr_err("bootconfig size %d is greater than initrd size %ld\n", size, initrd_end - initrd_start); return NULL; } /* Remove bootconfig from initramfs/initrd */ initrd_end = (unsigned long)data; if (_size) *_size = size; if (_csum) *_csum = csum; return data; } #else static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum) { return NULL; } #endif #ifdef CONFIG_BOOT_CONFIG static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata; #define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0) static int __init xbc_snprint_cmdline(char *buf, size_t size, struct xbc_node *root) { struct xbc_node *knode, *vnode; char *end = buf + size; const char *val; int ret; xbc_node_for_each_key_value(root, knode, val) { ret = xbc_node_compose_key_after(root, knode, xbc_namebuf, XBC_KEYLEN_MAX); if (ret < 0) return ret; vnode = xbc_node_get_child(knode); if (!vnode) { ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf); if (ret < 0) return ret; buf += ret; continue; } xbc_array_for_each_value(vnode, val) { ret = snprintf(buf, rest(buf, end), "%s=\"%s\" ", xbc_namebuf, val); if (ret < 0) return ret; buf += ret; } } return buf - (end - size); } #undef rest /* Make an extra command line under given key word */ static char * __init xbc_make_cmdline(const char *key) { struct xbc_node *root; char *new_cmdline; int ret, len = 0; root = xbc_find_node(key); if (!root) return NULL; /* Count required buffer size */ len = xbc_snprint_cmdline(NULL, 0, root); if (len <= 0) return NULL; new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES); if (!new_cmdline) { pr_err("Failed to allocate memory for extra kernel cmdline.\n"); return NULL; } ret = xbc_snprint_cmdline(new_cmdline, len + 1, root); if (ret < 0 || ret > len) { pr_err("Failed to print extra kernel cmdline.\n"); return NULL; } return new_cmdline; } static u32 boot_config_checksum(unsigned char *p, u32 size) { u32 ret = 0; while (size--) ret += *p++; return ret; } static int __init bootconfig_params(char *param, char *val, const char *unused, void *arg) { if (strcmp(param, "bootconfig") == 0) { bootconfig_found = true; } return 0; } static void __init setup_boot_config(const char *cmdline) { static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; const char *msg; int pos; u32 size, csum; char *data, *copy, *err; int ret; /* Cut out the bootconfig data even if we have no bootconfig option */ data = get_boot_config_from_initrd(&size, &csum); strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL, bootconfig_params); if (IS_ERR(err) || !bootconfig_found) return; /* parse_args() stops at '--' and returns an address */ if (err) initargs_found = true; if (!data) { pr_err("'bootconfig' found on command line, but no bootconfig found\n"); return; } if (size >= XBC_DATA_MAX) { pr_err("bootconfig size %d greater than max size %d\n", size, XBC_DATA_MAX); return; } if (boot_config_checksum((unsigned char *)data, size) != csum) { pr_err("bootconfig checksum failed\n"); return; } copy = memblock_alloc(size + 1, SMP_CACHE_BYTES); if (!copy) { pr_err("Failed to allocate memory for bootconfig\n"); return; } memcpy(copy, data, size); copy[size] = '\0'; ret = xbc_init(copy, &msg, &pos); if (ret < 0) { if (pos < 0) pr_err("Failed to init bootconfig: %s.\n", msg); else pr_err("Failed to parse bootconfig: %s at %d.\n", msg, pos); } else { pr_info("Load bootconfig: %d bytes %d nodes\n", size, ret); /* keys starting with "kernel." are passed via cmdline */ extra_command_line = xbc_make_cmdline("kernel"); /* Also, "init." keys are init arguments */ extra_init_args = xbc_make_cmdline("init"); } return; } #else static void __init setup_boot_config(const char *cmdline) { /* Remove bootconfig data from initrd */ get_boot_config_from_initrd(NULL, NULL); } static int __init warn_bootconfig(char *str) { pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n"); return 0; } early_param("bootconfig", warn_bootconfig); #endif /* Change NUL term back to "=", to make "param" the whole string. */ static void __init repair_env_string(char *param, char *val) { if (val) { /* param=val or param="val"? */ if (val == param+strlen(param)+1) val[-1] = '='; else if (val == param+strlen(param)+2) { val[-2] = '='; memmove(val-1, val, strlen(val)+1); } else BUG(); } } /* Anything after -- gets handed straight to init. */ static int __init set_init_arg(char *param, char *val, const char *unused, void *arg) { unsigned int i; if (panic_later) return 0; repair_env_string(param, val); for (i = 0; argv_init[i]; i++) { if (i == MAX_INIT_ARGS) { panic_later = "init"; panic_param = param; return 0; } } argv_init[i] = param; return 0; } /* * Unknown boot options get handed to init, unless they look like * unused parameters (modprobe will find them in /proc/cmdline). */ static int __init unknown_bootoption(char *param, char *val, const char *unused, void *arg) { size_t len = strlen(param); repair_env_string(param, val); /* Handle obsolete-style parameters */ if (obsolete_checksetup(param)) return 0; /* Unused module parameter. */ if (strnchr(param, len, '.')) return 0; if (panic_later) return 0; if (val) { /* Environment option */ unsigned int i; for (i = 0; envp_init[i]; i++) { if (i == MAX_INIT_ENVS) { panic_later = "env"; panic_param = param; } if (!strncmp(param, envp_init[i], len+1)) break; } envp_init[i] = param; } else { /* Command line option */ unsigned int i; for (i = 0; argv_init[i]; i++) { if (i == MAX_INIT_ARGS) { panic_later = "init"; panic_param = param; } } argv_init[i] = param; } return 0; } static int __init init_setup(char *str) { unsigned int i; execute_command = str; /* * In case LILO is going to boot us with default command line, * it prepends "auto" before the whole cmdline which makes * the shell think it should execute a script with such name. * So we ignore all arguments entered _before_ init=... [MJ] */ for (i = 1; i < MAX_INIT_ARGS; i++) argv_init[i] = NULL; return 1; } __setup("init=", init_setup); static int __init rdinit_setup(char *str) { unsigned int i; ramdisk_execute_command = str; /* See "auto" comment in init_setup */ for (i = 1; i < MAX_INIT_ARGS; i++) argv_init[i] = NULL; return 1; } __setup("rdinit=", rdinit_setup); #ifndef CONFIG_SMP static const unsigned int setup_max_cpus = NR_CPUS; static inline void setup_nr_cpu_ids(void) { } static inline void smp_prepare_cpus(unsigned int maxcpus) { } #endif /* * We need to store the untouched command line for future reference. * We also need to store the touched command line since the parameter * parsing is performed in place, and we should allow a component to * store reference of name/value for future reference. */ static void __init setup_command_line(char *command_line) { size_t len, xlen = 0, ilen = 0; if (extra_command_line) xlen = strlen(extra_command_line); if (extra_init_args) ilen = strlen(extra_init_args) + 4; /* for " -- " */ len = xlen + strlen(boot_command_line) + 1; saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES); if (!saved_command_line) panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen); static_command_line = memblock_alloc(len, SMP_CACHE_BYTES); if (!static_command_line) panic("%s: Failed to allocate %zu bytes\n", __func__, len); if (xlen) { /* * We have to put extra_command_line before boot command * lines because there could be dashes (separator of init * command line) in the command lines. */ strcpy(saved_command_line, extra_command_line); strcpy(static_command_line, extra_command_line); } strcpy(saved_command_line + xlen, boot_command_line); strcpy(static_command_line + xlen, command_line); if (ilen) { /* * Append supplemental init boot args to saved_command_line * so that user can check what command line options passed * to init. */ len = strlen(saved_command_line); if (initargs_found) { saved_command_line[len++] = ' '; } else { strcpy(saved_command_line + len, " -- "); len += 4; } strcpy(saved_command_line + len, extra_init_args); } } /* * We need to finalize in a non-__init function or else race conditions * between the root thread and the init thread may cause start_kernel to * be reaped by free_initmem before the root thread has proceeded to * cpu_idle. * * gcc-3.4 accidentally inlines this function, so use noinline. */ static __initdata DECLARE_COMPLETION(kthreadd_done); noinline void __ref rest_init(void) { struct task_struct *tsk; int pid; rcu_scheduler_starting(); /* * We need to spawn init first so that it obtains pid 1, however * the init task will end up wanting to create kthreads, which, if * we schedule it before we create kthreadd, will OOPS. */ pid = kernel_thread(kernel_init, NULL, CLONE_FS); /* * Pin init on the boot CPU. Task migration is not properly working * until sched_init_smp() has been run. It will set the allowed * CPUs for init to the non isolated CPUs. */ rcu_read_lock(); tsk = find_task_by_pid_ns(pid, &init_pid_ns); set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); rcu_read_unlock(); numa_default_policy(); pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES); rcu_read_lock(); kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); rcu_read_unlock(); /* * Enable might_sleep() and smp_processor_id() checks. * They cannot be enabled earlier because with CONFIG_PREEMPTION=y * kernel_thread() would trigger might_sleep() splats. With * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled * already, but it's stuck on the kthreadd_done completion. */ system_state = SYSTEM_SCHEDULING; complete(&kthreadd_done); /* * The boot idle thread must execute schedule() * at least once to get things moving: */ schedule_preempt_disabled(); /* Call into cpu_idle with preempt disabled */ cpu_startup_entry(CPUHP_ONLINE); } /* Check for early params. */ static int __init do_early_param(char *param, char *val, const char *unused, void *arg) { const struct obs_kernel_param *p; for (p = __setup_start; p < __setup_end; p++) { if ((p->early && parameq(param, p->str)) || (strcmp(param, "console") == 0 && strcmp(p->str, "earlycon") == 0) ) { if (p->setup_func(val) != 0) pr_warn("Malformed early option '%s'\n", param); } } /* We accept everything at this stage. */ return 0; } void __init parse_early_options(char *cmdline) { parse_args("early options", cmdline, NULL, 0, 0, 0, NULL, do_early_param); } /* Arch code calls this early on, or if not, just before other parsing. */ void __init parse_early_param(void) { static int done __initdata; static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata; if (done) return; /* All fall through to do_early_param. */ strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE); parse_early_options(tmp_cmdline); done = 1; } void __init __weak arch_post_acpi_subsys_init(void) { } void __init __weak smp_setup_processor_id(void) { } # if THREAD_SIZE >= PAGE_SIZE void __init __weak thread_stack_cache_init(void) { } #endif void __init __weak mem_encrypt_init(void) { } void __init __weak poking_init(void) { } void __init __weak pgtable_cache_init(void) { } bool initcall_debug; core_param(initcall_debug, initcall_debug, bool, 0644); #ifdef TRACEPOINTS_ENABLED static void __init initcall_debug_enable(void); #else static inline void initcall_debug_enable(void) { } #endif /* Report memory auto-initialization states for this boot. */ static void __init report_meminit(void) { const char *stack; if (IS_ENABLED(CONFIG_INIT_STACK_ALL_PATTERN)) stack = "all(pattern)"; else if (IS_ENABLED(CONFIG_INIT_STACK_ALL_ZERO)) stack = "all(zero)"; else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL)) stack = "byref_all(zero)"; else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF)) stack = "byref(zero)"; else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER)) stack = "__user(zero)"; else stack = "off"; pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n", stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off", want_init_on_free() ? "on" : "off"); if (want_init_on_free()) pr_info("mem auto-init: clearing system memory may take some time...\n"); } /* * Set up kernel memory allocators */ static void __init mm_init(void) { /* * page_ext requires contiguous pages, * bigger than MAX_ORDER unless SPARSEMEM. */ page_ext_init_flatmem(); init_mem_debugging_and_hardening(); kfence_alloc_pool(); report_meminit(); stack_depot_init(); mem_init(); mem_init_print_info(); /* page_owner must be initialized after buddy is ready */ page_ext_init_flatmem_late(); kmem_cache_init(); kmemleak_init(); pgtable_init(); debug_objects_mem_init(); vmalloc_init(); /* Should be run before the first non-init thread is created */ init_espfix_bsp(); /* Should be run after espfix64 is set up. */ pti_init(); } #ifdef CONFIG_HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT, randomize_kstack_offset); DEFINE_PER_CPU(u32, kstack_offset); static int __init early_randomize_kstack_offset(char *buf) { int ret; bool bool_result; ret = kstrtobool(buf, &bool_result); if (ret) return ret; if (bool_result) static_branch_enable(&randomize_kstack_offset); else static_branch_disable(&randomize_kstack_offset); return 0; } early_param("randomize_kstack_offset", early_randomize_kstack_offset); #endif void __init __weak arch_call_rest_init(void) { rest_init(); } asmlinkage __visible void __init __no_sanitize_address start_kernel(void) { char *command_line; char *after_dashes; set_task_stack_end_magic(&init_task); smp_setup_processor_id(); debug_objects_early_init(); cgroup_init_early(); local_irq_disable(); early_boot_irqs_disabled = true; /* * Interrupts are still disabled. Do necessary setups, then * enable them. */ boot_cpu_init(); page_address_init(); pr_notice("%s", linux_banner); early_security_init(); setup_arch(&command_line); setup_boot_config(command_line); setup_command_line(command_line); setup_nr_cpu_ids(); setup_per_cpu_areas(); smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ boot_cpu_hotplug_init(); build_all_zonelists(NULL); page_alloc_init(); pr_notice("Kernel command line: %s\n", saved_command_line); /* parameters may set static keys */ jump_label_init(); parse_early_param(); after_dashes = parse_args("Booting kernel", static_command_line, __start___param, __stop___param - __start___param, -1, -1, NULL, &unknown_bootoption); if (!IS_ERR_OR_NULL(after_dashes)) parse_args("Setting init args", after_dashes, NULL, 0, -1, -1, NULL, set_init_arg); if (extra_init_args) parse_args("Setting extra init args", extra_init_args, NULL, 0, -1, -1, NULL, set_init_arg); /* * These use large bootmem allocations and must precede * kmem_cache_init() */ setup_log_buf(0); vfs_caches_init_early(); sort_main_extable(); trap_init(); mm_init(); ftrace_init(); /* trace_printk can be enabled here */ early_trace_init(); /* * Set up the scheduler prior starting any interrupts (such as the * timer interrupt). Full topology setup happens at smp_init() * time - but meanwhile we still have a functioning scheduler. */ sched_init(); /* * Disable preemption - early bootup scheduling is extremely * fragile until we cpu_idle() for the first time. */ preempt_disable(); if (WARN(!irqs_disabled(), "Interrupts were enabled *very* early, fixing it\n")) local_irq_disable(); radix_tree_init(); /* * Set up housekeeping before setting up workqueues to allow the unbound * workqueue to take non-housekeeping into account. */ housekeeping_init(); /* * Allow workqueue creation and work item queueing/cancelling * early. Work item execution depends on kthreads and starts after * workqueue_init(). */ workqueue_init_early(); rcu_init(); /* Trace events are available after this */ trace_init(); if (initcall_debug) initcall_debug_enable(); context_tracking_init(); /* init some links before init_ISA_irqs() */ early_irq_init(); init_IRQ(); tick_init(); rcu_init_nohz(); init_timers(); hrtimers_init(); softirq_init(); timekeeping_init(); kfence_init(); /* * For best initial stack canary entropy, prepare it after: * - setup_arch() for any UEFI RNG entropy and boot cmdline access * - timekeeping_init() for ktime entropy used in rand_initialize() * - rand_initialize() to get any arch-specific entropy like RDRAND * - add_latent_entropy() to get any latent entropy * - adding command line entropy */ rand_initialize(); add_latent_entropy(); add_device_randomness(command_line, strlen(command_line)); boot_init_stack_canary(); time_init(); perf_event_init(); profile_init(); call_function_init(); WARN(!irqs_disabled(), "Interrupts were enabled early\n"); early_boot_irqs_disabled = false; local_irq_enable(); kmem_cache_init_late(); /* * HACK ALERT! This is early. We're enabling the console before * we've done PCI setups etc, and console_init() must be aware of * this. But we do want output early, in case something goes wrong. */ console_init(); if (panic_later) panic("Too many boot %s vars at `%s'", panic_later, panic_param); lockdep_init(); /* * Need to run this when irqs are enabled, because it wants * to self-test [hard/soft]-irqs on/off lock inversion bugs * too: */ locking_selftest(); /* * This needs to be called before any devices perform DMA * operations that might use the SWIOTLB bounce buffers. It will * mark the bounce buffers as decrypted so that their usage will * not cause "plain-text" data to be decrypted when accessed. */ mem_encrypt_init(); #ifdef CONFIG_BLK_DEV_INITRD if (initrd_start && !initrd_below_start_ok && page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n", page_to_pfn(virt_to_page((void *)initrd_start)), min_low_pfn); initrd_start = 0; } #endif setup_per_cpu_pageset(); numa_policy_init(); acpi_early_init(); if (late_time_init) late_time_init(); sched_clock_init(); calibrate_delay(); pid_idr_init(); anon_vma_init(); #ifdef CONFIG_X86 if (efi_enabled(EFI_RUNTIME_SERVICES)) efi_enter_virtual_mode(); #endif thread_stack_cache_init(); cred_init(); fork_init(); proc_caches_init(); uts_ns_init(); key_init(); security_init(); dbg_late_init(); vfs_caches_init(); pagecache_init(); signals_init(); seq_file_init(); proc_root_init(); nsfs_init(); cpuset_init(); cgroup_init(); taskstats_init_early(); delayacct_init(); poking_init(); check_bugs(); acpi_subsystem_init(); arch_post_acpi_subsys_init(); kcsan_init(); /* Do the rest non-__init'ed, we're now alive */ arch_call_rest_init(); prevent_tail_call_optimization(); } /* Call all constructor functions linked into the kernel. */ static void __init do_ctors(void) { /* * For UML, the constructors have already been called by the * normal setup code as it's just a normal ELF binary, so we * cannot do it again - but we do need CONFIG_CONSTRUCTORS * even on UML for modules. */ #if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML) ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; for (; fn < (ctor_fn_t *) __ctors_end; fn++) (*fn)(); #endif } #ifdef CONFIG_KALLSYMS struct blacklist_entry { struct list_head next; char *buf; }; static __initdata_or_module LIST_HEAD(blacklisted_initcalls); static int __init initcall_blacklist(char *str) { char *str_entry; struct blacklist_entry *entry; /* str argument is a comma-separated list of functions */ do { str_entry = strsep(&str, ","); if (str_entry) { pr_debug("blacklisting initcall %s\n", str_entry); entry = memblock_alloc(sizeof(*entry), SMP_CACHE_BYTES); if (!entry) panic("%s: Failed to allocate %zu bytes\n", __func__, sizeof(*entry)); entry->buf = memblock_alloc(strlen(str_entry) + 1, SMP_CACHE_BYTES); if (!entry->buf) panic("%s: Failed to allocate %zu bytes\n", __func__, strlen(str_entry) + 1); strcpy(entry->buf, str_entry); list_add(&entry->next, &blacklisted_initcalls); } } while (str_entry); return 0; } static bool __init_or_module initcall_blacklisted(initcall_t fn) { struct blacklist_entry *entry; char fn_name[KSYM_SYMBOL_LEN]; unsigned long addr; if (list_empty(&blacklisted_initcalls)) return false; addr = (unsigned long) dereference_function_descriptor(fn); sprint_symbol_no_offset(fn_name, addr); /* * fn will be "function_name [module_name]" where [module_name] is not * displayed for built-in init functions. Strip off the [module_name]. */ strreplace(fn_name, ' ', '\0'); list_for_each_entry(entry, &blacklisted_initcalls, next) { if (!strcmp(fn_name, entry->buf)) { pr_debug("initcall %s blacklisted\n", fn_name); return true; } } return false; } #else static int __init initcall_blacklist(char *str) { pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n"); return 0; } static bool __init_or_module initcall_blacklisted(initcall_t fn) { return false; } #endif __setup("initcall_blacklist=", initcall_blacklist); static __init_or_module void trace_initcall_start_cb(void *data, initcall_t fn) { ktime_t *calltime = (ktime_t *)data; printk(KERN_DEBUG "calling %pS @ %i\n", fn, task_pid_nr(current)); *calltime = ktime_get(); } static __init_or_module void trace_initcall_finish_cb(void *data, initcall_t fn, int ret) { ktime_t *calltime = (ktime_t *)data; ktime_t delta, rettime; unsigned long long duration; rettime = ktime_get(); delta = ktime_sub(rettime, *calltime); duration = (unsigned long long) ktime_to_ns(delta) >> 10; printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n", fn, ret, duration); } static ktime_t initcall_calltime; #ifdef TRACEPOINTS_ENABLED static void __init initcall_debug_enable(void) { int ret; ret = register_trace_initcall_start(trace_initcall_start_cb, &initcall_calltime); ret |= register_trace_initcall_finish(trace_initcall_finish_cb, &initcall_calltime); WARN(ret, "Failed to register initcall tracepoints\n"); } # define do_trace_initcall_start trace_initcall_start # define do_trace_initcall_finish trace_initcall_finish #else static inline void do_trace_initcall_start(initcall_t fn) { if (!initcall_debug) return; trace_initcall_start_cb(&initcall_calltime, fn); } static inline void do_trace_initcall_finish(initcall_t fn, int ret) { if (!initcall_debug) return; trace_initcall_finish_cb(&initcall_calltime, fn, ret); } #endif /* !TRACEPOINTS_ENABLED */ int __init_or_module do_one_initcall(initcall_t fn) { int count = preempt_count(); char msgbuf[64]; int ret; if (initcall_blacklisted(fn)) return -EPERM; do_trace_initcall_start(fn); ret = fn(); do_trace_initcall_finish(fn, ret); msgbuf[0] = 0; if (preempt_count() != count) { sprintf(msgbuf, "preemption imbalance "); preempt_count_set(count); } if (irqs_disabled()) { strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); local_irq_enable(); } WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf); add_latent_entropy(); return ret; } extern initcall_entry_t __initcall_start[]; extern initcall_entry_t __initcall0_start[]; extern initcall_entry_t __initcall1_start[]; extern initcall_entry_t __initcall2_start[]; extern initcall_entry_t __initcall3_start[]; extern initcall_entry_t __initcall4_start[]; extern initcall_entry_t __initcall5_start[]; extern initcall_entry_t __initcall6_start[]; extern initcall_entry_t __initcall7_start[]; extern initcall_entry_t __initcall_end[]; static initcall_entry_t *initcall_levels[] __initdata = { __initcall0_start, __initcall1_start, __initcall2_start, __initcall3_start, __initcall4_start, __initcall5_start, __initcall6_start, __initcall7_start, __initcall_end, }; /* Keep these in sync with initcalls in include/linux/init.h */ static const char *initcall_level_names[] __initdata = { "pure", "core", "postcore", "arch", "subsys", "fs", "device", "late", }; static int __init ignore_unknown_bootoption(char *param, char *val, const char *unused, void *arg) { return 0; } static void __init do_initcall_level(int level, char *command_line) { initcall_entry_t *fn; parse_args(initcall_level_names[level], command_line, __start___param, __stop___param - __start___param, level, level, NULL, ignore_unknown_bootoption); trace_initcall_level(initcall_level_names[level]); for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) do_one_initcall(initcall_from_entry(fn)); } static void __init do_initcalls(void) { int level; size_t len = strlen(saved_command_line) + 1; char *command_line; command_line = kzalloc(len, GFP_KERNEL); if (!command_line) panic("%s: Failed to allocate %zu bytes\n", __func__, len); for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) { /* Parser modifies command_line, restore it each time */ strcpy(command_line, saved_command_line); do_initcall_level(level, command_line); } kfree(command_line); } /* * Ok, the machine is now initialized. None of the devices * have been touched yet, but the CPU subsystem is up and * running, and memory and process management works. * * Now we can finally start doing some real work.. */ static void __init do_basic_setup(void) { cpuset_init_smp(); driver_init(); init_irq_proc(); do_ctors(); usermodehelper_enable(); do_initcalls(); } static void __init do_pre_smp_initcalls(void) { initcall_entry_t *fn; trace_initcall_level("early"); for (fn = __initcall_start; fn < __initcall0_start; fn++) do_one_initcall(initcall_from_entry(fn)); } static int run_init_process(const char *init_filename) { const char *const *p; argv_init[0] = init_filename; pr_info("Run %s as init process\n", init_filename); pr_debug(" with arguments:\n"); for (p = argv_init; *p; p++) pr_debug(" %s\n", *p); pr_debug(" with environment:\n"); for (p = envp_init; *p; p++) pr_debug(" %s\n", *p); return kernel_execve(init_filename, argv_init, envp_init); } static int try_to_run_init_process(const char *init_filename) { int ret; ret = run_init_process(init_filename); if (ret && ret != -ENOENT) { pr_err("Starting init: %s exists but couldn't execute it (error %d)\n", init_filename, ret); } return ret; } static noinline void __init kernel_init_freeable(void); #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX) bool rodata_enabled __ro_after_init = true; static int __init set_debug_rodata(char *str) { return strtobool(str, &rodata_enabled); } __setup("rodata=", set_debug_rodata); #endif #ifdef CONFIG_STRICT_KERNEL_RWX static void mark_readonly(void) { if (rodata_enabled) { /* * load_module() results in W+X mappings, which are cleaned * up with call_rcu(). Let's make sure that queued work is * flushed so that we don't hit false positives looking for * insecure pages which are W+X. */ rcu_barrier(); mark_rodata_ro(); rodata_test(); } else pr_info("Kernel memory protection disabled.\n"); } #elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX) static inline void mark_readonly(void) { pr_warn("Kernel memory protection not selected by kernel config.\n"); } #else static inline void mark_readonly(void) { pr_warn("This architecture does not have kernel memory protection.\n"); } #endif void __weak free_initmem(void) { free_initmem_default(POISON_FREE_INITMEM); } static int __ref kernel_init(void *unused) { int ret; kernel_init_freeable(); /* need to finish all async __init code before freeing the memory */ async_synchronize_full(); kprobe_free_init_mem(); ftrace_free_init_mem(); kgdb_free_init_mem(); free_initmem(); mark_readonly(); /* * Kernel mappings are now finalized - update the userspace page-table * to finalize PTI. */ pti_finalize(); system_state = SYSTEM_RUNNING; numa_default_policy(); rcu_end_inkernel_boot(); do_sysctl_args(); if (ramdisk_execute_command) { ret = run_init_process(ramdisk_execute_command); if (!ret) return 0; pr_err("Failed to execute %s (error %d)\n", ramdisk_execute_command, ret); } /* * We try each of these until one succeeds. * * The Bourne shell can be used instead of init if we are * trying to recover a really broken machine. */ if (execute_command) { ret = run_init_process(execute_command); if (!ret) return 0; panic("Requested init %s failed (error %d).", execute_command, ret); } if (CONFIG_DEFAULT_INIT[0] != '\0') { ret = run_init_process(CONFIG_DEFAULT_INIT); if (ret) pr_err("Default init %s failed (error %d)\n", CONFIG_DEFAULT_INIT, ret); else return 0; } if (!try_to_run_init_process("/sbin/init") || !try_to_run_init_process("/etc/init") || !try_to_run_init_process("/bin/init") || !try_to_run_init_process("/bin/sh")) return 0; panic("No working init found. Try passing init= option to kernel. " "See Linux Documentation/admin-guide/init.rst for guidance."); } /* Open /dev/console, for stdin/stdout/stderr, this should never fail */ void __init console_on_rootfs(void) { struct file *file = filp_open("/dev/console", O_RDWR, 0); if (IS_ERR(file)) { pr_err("Warning: unable to open an initial console.\n"); return; } init_dup(file); init_dup(file); init_dup(file); fput(file); } static noinline void __init kernel_init_freeable(void) { /* * Wait until kthreadd is all set-up. */ wait_for_completion(&kthreadd_done); /* Now the scheduler is fully set up and can do blocking allocations */ gfp_allowed_mask = __GFP_BITS_MASK; /* * init can allocate pages on any node */ set_mems_allowed(node_states[N_MEMORY]); cad_pid = task_pid(current); smp_prepare_cpus(setup_max_cpus); workqueue_init(); init_mm_internals(); rcu_init_tasks_generic(); do_pre_smp_initcalls(); lockup_detector_init(); smp_init(); sched_init_smp(); padata_init(); page_alloc_init_late(); /* Initialize page ext after all struct pages are initialized. */ page_ext_init(); do_basic_setup(); kunit_run_all_tests(); wait_for_initramfs(); console_on_rootfs(); /* * check if there is an early userspace init. If yes, let it do all * the work */ if (init_eaccess(ramdisk_execute_command) != 0) { ramdisk_execute_command = NULL; prepare_namespace(); } /* * Ok, we have completed the initial bootup, and * we're essentially up and running. Get rid of the * initmem segments and start the user-mode stuff.. * * rootfs is available now, try loading the public keys * and default modules */ integrity_load_keys(); }