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Diffstat (limited to 'init/main.c')
| -rw-r--r-- | init/main.c | 1184 |
1 files changed, 1184 insertions, 0 deletions
diff --git a/init/main.c b/init/main.c new file mode 100644 index 000000000..489a5aa7b --- /dev/null +++ b/init/main.c @@ -0,0 +1,1184 @@ +/* + * 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 <grif@acm.org> + */ + +#define DEBUG /* Enable initcall_debug */ + +#include <linux/types.h> +#include <linux/extable.h> +#include <linux/module.h> +#include <linux/proc_fs.h> +#include <linux/binfmts.h> +#include <linux/kernel.h> +#include <linux/syscalls.h> +#include <linux/stackprotector.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <linux/delay.h> +#include <linux/ioport.h> +#include <linux/init.h> +#include <linux/initrd.h> +#include <linux/bootmem.h> +#include <linux/acpi.h> +#include <linux/console.h> +#include <linux/nmi.h> +#include <linux/percpu.h> +#include <linux/kmod.h> +#include <linux/vmalloc.h> +#include <linux/kernel_stat.h> +#include <linux/start_kernel.h> +#include <linux/security.h> +#include <linux/smp.h> +#include <linux/profile.h> +#include <linux/rcupdate.h> +#include <linux/moduleparam.h> +#include <linux/kallsyms.h> +#include <linux/writeback.h> +#include <linux/cpu.h> +#include <linux/cpuset.h> +#include <linux/cgroup.h> +#include <linux/efi.h> +#include <linux/tick.h> +#include <linux/sched/isolation.h> +#include <linux/interrupt.h> +#include <linux/taskstats_kern.h> +#include <linux/delayacct.h> +#include <linux/unistd.h> +#include <linux/utsname.h> +#include <linux/rmap.h> +#include <linux/mempolicy.h> +#include <linux/key.h> +#include <linux/buffer_head.h> +#include <linux/page_ext.h> +#include <linux/debug_locks.h> +#include <linux/debugobjects.h> +#include <linux/lockdep.h> +#include <linux/kmemleak.h> +#include <linux/pid_namespace.h> +#include <linux/device.h> +#include <linux/kthread.h> +#include <linux/sched.h> +#include <linux/sched/init.h> +#include <linux/signal.h> +#include <linux/idr.h> +#include <linux/kgdb.h> +#include <linux/ftrace.h> +#include <linux/async.h> +#include <linux/sfi.h> +#include <linux/shmem_fs.h> +#include <linux/slab.h> +#include <linux/perf_event.h> +#include <linux/ptrace.h> +#include <linux/pti.h> +#include <linux/blkdev.h> +#include <linux/elevator.h> +#include <linux/sched/clock.h> +#include <linux/sched/task.h> +#include <linux/sched/task_stack.h> +#include <linux/context_tracking.h> +#include <linux/random.h> +#include <linux/list.h> +#include <linux/integrity.h> +#include <linux/proc_ns.h> +#include <linux/io.h> +#include <linux/cache.h> +#include <linux/rodata_test.h> +#include <linux/jump_label.h> +#include <linux/mem_encrypt.h> + +#include <asm/io.h> +#include <asm/bugs.h> +#include <asm/setup.h> +#include <asm/sections.h> +#include <asm/cacheflush.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/initcall.h> + +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; +/* Command line for per-initcall parameter parsing */ +static char *initcall_command_line; + +static char *execute_command; +static char *ramdisk_execute_command; + +/* + * 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); + +/* Change NUL term back to "=", to make "param" the whole string. */ +static int __init repair_env_string(char *param, char *val, + const char *unused, void *arg) +{ + 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); + val--; + } else + BUG(); + } + return 0; +} + +/* 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, unused, NULL); + + 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) +{ + repair_env_string(param, val, unused, NULL); + + /* Handle obsolete-style parameters */ + if (obsolete_checksetup(param)) + return 0; + + /* Unused module parameter. */ + if (strchr(param, '.') && (!val || strchr(param, '.') < val)) + 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], val - param)) + 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) +{ + saved_command_line = + memblock_virt_alloc(strlen(boot_command_line) + 1, 0); + initcall_command_line = + memblock_virt_alloc(strlen(boot_command_line) + 1, 0); + static_command_line = memblock_virt_alloc(strlen(command_line) + 1, 0); + strcpy(saved_command_line, boot_command_line); + strcpy(static_command_line, command_line); +} + +/* + * 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); + +static 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_PREEMPT=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) { } + +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 + +/* + * 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(); + mem_init(); + kmem_cache_init(); + pgtable_init(); + vmalloc_init(); + ioremap_huge_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(); +} + +asmlinkage __visible void __init 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); + setup_arch(&command_line); + mm_init_cpumask(&init_mm); + 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", boot_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); + + /* + * 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(); + time_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 random_init() + * - time_init() for making random_get_entropy() work on some platforms + * - random_init() to initialize the RNG from from early entropy sources + */ + random_init(command_line); + boot_init_stack_canary(); + + 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 + kmemleak_init(); + debug_objects_mem_init(); + 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(); + buffer_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(); + + check_bugs(); + + acpi_subsystem_init(); + arch_post_acpi_subsys_init(); + sfi_init_late(); + + if (efi_enabled(EFI_RUNTIME_SERVICES)) { + efi_free_boot_services(); + } + + /* Do the rest non-__init'ed, we're now alive */ + rest_init(); + + prevent_tail_call_optimization(); +} + +/* Call all constructor functions linked into the kernel. */ +static void __init do_ctors(void) +{ +#ifdef CONFIG_CONSTRUCTORS + 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 = alloc_bootmem(sizeof(*entry)); + entry->buf = alloc_bootmem(strlen(str_entry) + 1); + strcpy(entry->buf, str_entry); + list_add(&entry->next, &blacklisted_initcalls); + } + } while (str_entry); + + return 1; +} + +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 %pF @ %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 %pF 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 %pF 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 char *initcall_level_names[] __initdata = { + "pure", + "core", + "postcore", + "arch", + "subsys", + "fs", + "device", + "late", +}; + +static void __init do_initcall_level(int level) +{ + initcall_entry_t *fn; + + strcpy(initcall_command_line, saved_command_line); + parse_args(initcall_level_names[level], + initcall_command_line, __start___param, + __stop___param - __start___param, + level, level, + NULL, &repair_env_string); + + 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; + + for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) + do_initcall_level(level); +} + +/* + * 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(); + shmem_init(); + 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)); +} + +/* + * This function requests modules which should be loaded by default and is + * called twice right after initrd is mounted and right before init is + * exec'd. If such modules are on either initrd or rootfs, they will be + * loaded before control is passed to userland. + */ +void __init load_default_modules(void) +{ + load_default_elevator_module(); +} + +static int run_init_process(const char *init_filename) +{ + argv_init[0] = init_filename; + pr_info("Run %s as init process\n", init_filename); + return do_execve(getname_kernel(init_filename), + (const char __user *const __user *)argv_init, + (const char __user *const __user *)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) +{ + if (strtobool(str, &rodata_enabled)) + pr_warn("Invalid option string for rodata: '%s'\n", str); + return 1; +} +__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_sched(). 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_sched(); + mark_rodata_ro(); + rodata_test(); + } else + pr_info("Kernel memory protection disabled.\n"); +} +#else +static inline void mark_readonly(void) +{ + pr_warn("This architecture does not have kernel memory protection.\n"); +} +#endif + +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(); + ftrace_free_init_mem(); + jump_label_invalidate_initmem(); + 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(); + + 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 (!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."); +} + +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 = get_pid(task_pid(current)); + + smp_prepare_cpus(setup_max_cpus); + + workqueue_init(); + + init_mm_internals(); + + do_pre_smp_initcalls(); + lockup_detector_init(); + + smp_init(); + sched_init_smp(); + + page_alloc_init_late(); + /* Initialize page ext after all struct pages are initialized. */ + page_ext_init(); + + do_basic_setup(); + + /* Open the /dev/console on the rootfs, this should never fail */ + if (ksys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0) + pr_err("Warning: unable to open an initial console.\n"); + + (void) ksys_dup(0); + (void) ksys_dup(0); + /* + * check if there is an early userspace init. If yes, let it do all + * the work + */ + + if (!ramdisk_execute_command) + ramdisk_execute_command = "/init"; + + if (ksys_access((const char __user *) + ramdisk_execute_command, 0) != 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(); + load_default_modules(); +} |