diff options
Diffstat (limited to 'init/main.c')
| -rw-r--r-- | init/main.c | 894 |
1 files changed, 894 insertions, 0 deletions
diff --git a/init/main.c b/init/main.c new file mode 100644 index 00000000..b08c5f75 --- /dev/null +++ b/init/main.c @@ -0,0 +1,894 @@ +/* + * 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> + */ + +#include <linux/types.h> +#include <linux/module.h> +#include <linux/proc_fs.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/tty.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/interrupt.h> +#include <linux/taskstats_kern.h> +#include <linux/delayacct.h> +#include <linux/unistd.h> +#include <linux/rmap.h> +#include <linux/mempolicy.h> +#include <linux/key.h> +#include <linux/buffer_head.h> +#include <linux/page_cgroup.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/signal.h> +#include <linux/idr.h> +#include <linux/kgdb.h> +#include <linux/ftrace.h> +#include <linux/async.h> +#include <linux/kmemcheck.h> +#include <linux/sfi.h> +#include <linux/shmem_fs.h> +#include <linux/slab.h> +#include <linux/perf_event.h> + +#include <asm/io.h> +#include <asm/bugs.h> +#include <asm/setup.h> +#include <asm/sections.h> +#include <asm/cacheflush.h> + +#ifdef CONFIG_X86_LOCAL_APIC +#include <asm/smp.h> +#endif + +static int kernel_init(void *); + +extern void init_IRQ(void); +extern void fork_init(unsigned long); +extern void mca_init(void); +extern void sbus_init(void); +extern void prio_tree_init(void); +extern void radix_tree_init(void); +#ifndef CONFIG_DEBUG_RODATA +static inline void mark_rodata_ro(void) { } +#endif + +#ifdef CONFIG_TC +extern void tc_init(void); +#endif + +/* + * 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); +extern void softirq_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; + +static char *execute_command; +static char *ramdisk_execute_command; + +/* + * 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 situaiton 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 int __init obsolete_checksetup(char *line) +{ + const struct obs_kernel_param *p; + int had_early_param = 0; + + 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 = 1; + } else if (!p->setup_func) { + printk(KERN_WARNING "Parameter %s is obsolete," + " ignored\n", p->str); + return 1; + } else if (p->setup_func(line + n)) + return 1; + } + 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 = 10; + return 0; +} + +static int __init quiet_kernel(char *str) +{ + console_loglevel = 4; + 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) +{ + 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; +} + +/* + * 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) +{ + repair_env_string(param, val); + + /* 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 = "Too many boot env vars at `%s'"; + 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 = "Too many boot init vars at `%s'"; + 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; +#ifdef CONFIG_X86_LOCAL_APIC +static void __init smp_init(void) +{ + APIC_init_uniprocessor(); +} +#else +#define smp_init() do { } while (0) +#endif + +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 = alloc_bootmem(strlen (boot_command_line)+1); + static_command_line = alloc_bootmem(strlen (command_line)+1); + 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 __init_refok rest_init(void) +{ + 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. + */ + kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND); + 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(); + complete(&kthreadd_done); + + /* + * The boot idle thread must execute schedule() + * at least once to get things moving: + */ + init_idle_bootup_task(current); + schedule_preempt_disabled(); + /* Call into cpu_idle with preempt disabled */ + cpu_idle(); +} + +/* Check for early params. */ +static int __init do_early_param(char *param, char *val) +{ + 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) + printk(KERN_WARNING + "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, do_early_param); +} + +/* Arch code calls this early on, or if not, just before other parsing. */ +void __init parse_early_param(void) +{ + static __initdata int done = 0; + static __initdata char tmp_cmdline[COMMAND_LINE_SIZE]; + + 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; +} + +/* + * Activate the first processor. + */ + +static void __init boot_cpu_init(void) +{ + int cpu = smp_processor_id(); + /* Mark the boot cpu "present", "online" etc for SMP and UP case */ + set_cpu_online(cpu, true); + set_cpu_active(cpu, true); + set_cpu_present(cpu, true); + set_cpu_possible(cpu, true); +} + +void __init __weak smp_setup_processor_id(void) +{ +} + +void __init __weak thread_info_cache_init(void) +{ +} + +/* + * Set up kernel memory allocators + */ +static void __init mm_init(void) +{ + /* + * page_cgroup requires contiguous pages, + * bigger than MAX_ORDER unless SPARSEMEM. + */ + page_cgroup_init_flatmem(); + mem_init(); + kmem_cache_init(); + percpu_init_late(); + pgtable_cache_init(); + vmalloc_init(); +} + +asmlinkage void __init start_kernel(void) +{ + char * command_line; + extern const struct kernel_param __start___param[], __stop___param[]; + + /* + * Need to run as early as possible, to initialize the + * lockdep hash: + */ + lockdep_init(); + smp_setup_processor_id(); + debug_objects_early_init(); + + /* + * Set up the the initial canary ASAP: + */ + boot_init_stack_canary(); + + cgroup_init_early(); + + local_irq_disable(); + early_boot_irqs_disabled = true; + +/* + * Interrupts are still disabled. Do necessary setups, then + * enable them + */ + tick_init(); + boot_cpu_init(); + page_address_init(); + printk(KERN_NOTICE "%s", linux_banner); + setup_arch(&command_line); + mm_init_owner(&init_mm, &init_task); + 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 */ + + build_all_zonelists(NULL); + page_alloc_init(); + + printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line); + parse_early_param(); + parse_args("Booting kernel", static_command_line, __start___param, + __stop___param - __start___param, + -1, -1, &unknown_bootoption); + + jump_label_init(); + + /* + * These use large bootmem allocations and must precede + * kmem_cache_init() + */ + setup_log_buf(0); + pidhash_init(); + vfs_caches_init_early(); + sort_main_extable(); + trap_init(); + mm_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 (!irqs_disabled()) { + printk(KERN_WARNING "start_kernel(): bug: interrupts were " + "enabled *very* early, fixing it\n"); + local_irq_disable(); + } + idr_init_cache(); + perf_event_init(); + rcu_init(); + radix_tree_init(); + /* init some links before init_ISA_irqs() */ + early_irq_init(); + init_IRQ(); + prio_tree_init(); + init_timers(); + hrtimers_init(); + softirq_init(); + timekeeping_init(); + time_init(); + profile_init(); + call_function_init(); + if (!irqs_disabled()) + printk(KERN_CRIT "start_kernel(): bug: 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(panic_later, panic_param); + + lockdep_info(); + + /* + * 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(); + +#ifdef CONFIG_BLK_DEV_INITRD + if (initrd_start && !initrd_below_start_ok && + page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { + printk(KERN_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 + page_cgroup_init(); + debug_objects_mem_init(); + kmemleak_init(); + setup_per_cpu_pageset(); + numa_policy_init(); + if (late_time_init) + late_time_init(); + sched_clock_init(); + calibrate_delay(); + pidmap_init(); + anon_vma_init(); +#ifdef CONFIG_X86 + if (efi_enabled) + efi_enter_virtual_mode(); +#endif + thread_info_cache_init(); + cred_init(); + fork_init(totalram_pages); + proc_caches_init(); + buffer_init(); + key_init(); + security_init(); + dbg_late_init(); + vfs_caches_init(totalram_pages); + signals_init(); + /* rootfs populating might need page-writeback */ + page_writeback_init(); +#ifdef CONFIG_PROC_FS + proc_root_init(); +#endif + cgroup_init(); + cpuset_init(); + taskstats_init_early(); + delayacct_init(); + + check_bugs(); + + acpi_early_init(); /* before LAPIC and SMP init */ + sfi_init_late(); + + ftrace_init(); + + /* Do the rest non-__init'ed, we're now alive */ + rest_init(); +} + +/* 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 +} + +bool initcall_debug; +core_param(initcall_debug, initcall_debug, bool, 0644); + +static char msgbuf[64]; + +static int __init_or_module do_one_initcall_debug(initcall_t fn) +{ + ktime_t calltime, delta, rettime; + unsigned long long duration; + int ret; + + printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current)); + calltime = ktime_get(); + ret = fn(); + 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); + + return ret; +} + +int __init_or_module do_one_initcall(initcall_t fn) +{ + int count = preempt_count(); + int ret; + + if (initcall_debug) + ret = do_one_initcall_debug(fn); + else + ret = fn(); + + msgbuf[0] = 0; + + if (ret && ret != -ENODEV && initcall_debug) + sprintf(msgbuf, "error code %d ", ret); + + if (preempt_count() != count) { + strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf)); + preempt_count() = count; + } + if (irqs_disabled()) { + strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); + local_irq_enable(); + } + if (msgbuf[0]) { + printk("initcall %pF returned with %s\n", fn, msgbuf); + } + + return ret; +} + + +extern initcall_t __initcall_start[]; +extern initcall_t __initcall0_start[]; +extern initcall_t __initcall1_start[]; +extern initcall_t __initcall2_start[]; +extern initcall_t __initcall3_start[]; +extern initcall_t __initcall4_start[]; +extern initcall_t __initcall5_start[]; +extern initcall_t __initcall6_start[]; +extern initcall_t __initcall7_start[]; +extern initcall_t __initcall_end[]; + +static initcall_t *initcall_levels[] __initdata = { + __initcall0_start, + __initcall1_start, + __initcall2_start, + __initcall3_start, + __initcall4_start, + __initcall5_start, + __initcall6_start, + __initcall7_start, + __initcall_end, +}; + +static char *initcall_level_names[] __initdata = { + "early parameters", + "core parameters", + "postcore parameters", + "arch parameters", + "subsys parameters", + "fs parameters", + "device parameters", + "late parameters", +}; + +static void __init do_initcall_level(int level) +{ + extern const struct kernel_param __start___param[], __stop___param[]; + initcall_t *fn; + + strcpy(static_command_line, saved_command_line); + parse_args(initcall_level_names[level], + static_command_line, __start___param, + __stop___param - __start___param, + level, level, + repair_env_string); + + for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++) + do_one_initcall(*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(); + usermodehelper_init(); + shmem_init(); + driver_init(); + init_irq_proc(); + do_ctors(); + usermodehelper_enable(); + do_initcalls(); +} + +static void __init do_pre_smp_initcalls(void) +{ + initcall_t *fn; + + for (fn = __initcall_start; fn < __initcall0_start; fn++) + do_one_initcall(*fn); +} + +static void run_init_process(const char *init_filename) +{ + argv_init[0] = init_filename; + kernel_execve(init_filename, argv_init, envp_init); +} + +/* This is a non __init function. Force it to be noinline otherwise gcc + * makes it inline to init() and it becomes part of init.text section + */ +static noinline int init_post(void) +{ + /* need to finish all async __init code before freeing the memory */ + async_synchronize_full(); + free_initmem(); + mark_rodata_ro(); + system_state = SYSTEM_RUNNING; + numa_default_policy(); + + + current->signal->flags |= SIGNAL_UNKILLABLE; + + if (ramdisk_execute_command) { + run_init_process(ramdisk_execute_command); + printk(KERN_WARNING "Failed to execute %s\n", + ramdisk_execute_command); + } + + /* + * 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) { + run_init_process(execute_command); + printk(KERN_WARNING "Failed to execute %s. Attempting " + "defaults...\n", execute_command); + } + run_init_process("/sbin/init"); + run_init_process("/etc/init"); + run_init_process("/bin/init"); + run_init_process("/bin/sh"); + + panic("No init found. Try passing init= option to kernel. " + "See Linux Documentation/init.txt for guidance."); +} + +static int __init kernel_init(void * unused) +{ + /* + * 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_HIGH_MEMORY]); + /* + * init can run on any cpu. + */ + set_cpus_allowed_ptr(current, cpu_all_mask); + + cad_pid = task_pid(current); + + smp_prepare_cpus(setup_max_cpus); + + do_pre_smp_initcalls(); + lockup_detector_init(); + + smp_init(); + sched_init_smp(); + + do_basic_setup(); + + /* Open the /dev/console on the rootfs, this should never fail */ + if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0) + printk(KERN_WARNING "Warning: unable to open an initial console.\n"); + + (void) sys_dup(0); + (void) sys_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 (sys_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.. + */ + + init_post(); + return 0; +} |