linux/init/main.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  linux/init/main.c
   4 *
   5 *  Copyright (C) 1991, 1992  Linus Torvalds
   6 *
   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>
  11 */
  12
  13#define DEBUG           /* Enable initcall_debug */
  14
  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/console.h>
  32#include <linux/nmi.h>
  33#include <linux/percpu.h>
  34#include <linux/kmod.h>
  35#include <linux/vmalloc.h>
  36#include <linux/kernel_stat.h>
  37#include <linux/start_kernel.h>
  38#include <linux/security.h>
  39#include <linux/smp.h>
  40#include <linux/profile.h>
  41#include <linux/rcupdate.h>
  42#include <linux/moduleparam.h>
  43#include <linux/kallsyms.h>
  44#include <linux/writeback.h>
  45#include <linux/cpu.h>
  46#include <linux/cpuset.h>
  47#include <linux/cgroup.h>
  48#include <linux/efi.h>
  49#include <linux/tick.h>
  50#include <linux/sched/isolation.h>
  51#include <linux/interrupt.h>
  52#include <linux/taskstats_kern.h>
  53#include <linux/delayacct.h>
  54#include <linux/unistd.h>
  55#include <linux/utsname.h>
  56#include <linux/rmap.h>
  57#include <linux/mempolicy.h>
  58#include <linux/key.h>
  59#include <linux/buffer_head.h>
  60#include <linux/page_ext.h>
  61#include <linux/debug_locks.h>
  62#include <linux/debugobjects.h>
  63#include <linux/lockdep.h>
  64#include <linux/kmemleak.h>
  65#include <linux/pid_namespace.h>
  66#include <linux/device.h>
  67#include <linux/kthread.h>
  68#include <linux/sched.h>
  69#include <linux/sched/init.h>
  70#include <linux/signal.h>
  71#include <linux/idr.h>
  72#include <linux/kgdb.h>
  73#include <linux/ftrace.h>
  74#include <linux/async.h>
  75#include <linux/sfi.h>
  76#include <linux/shmem_fs.h>
  77#include <linux/slab.h>
  78#include <linux/perf_event.h>
  79#include <linux/ptrace.h>
  80#include <linux/pti.h>
  81#include <linux/blkdev.h>
  82#include <linux/elevator.h>
  83#include <linux/sched/clock.h>
  84#include <linux/sched/task.h>
  85#include <linux/sched/task_stack.h>
  86#include <linux/context_tracking.h>
  87#include <linux/random.h>
  88#include <linux/list.h>
  89#include <linux/integrity.h>
  90#include <linux/proc_ns.h>
  91#include <linux/io.h>
  92#include <linux/cache.h>
  93#include <linux/rodata_test.h>
  94#include <linux/jump_label.h>
  95#include <linux/mem_encrypt.h>
  96
  97#include <asm/io.h>
  98#include <asm/bugs.h>
  99#include <asm/setup.h>
 100#include <asm/sections.h>
 101#include <asm/cacheflush.h>
 102
 103#define CREATE_TRACE_POINTS
 104#include <trace/events/initcall.h>
 105
 106static int kernel_init(void *);
 107
 108extern void init_IRQ(void);
 109extern void radix_tree_init(void);
 110
 111/*
 112 * Debug helper: via this flag we know that we are in 'early bootup code'
 113 * where only the boot processor is running with IRQ disabled.  This means
 114 * two things - IRQ must not be enabled before the flag is cleared and some
 115 * operations which are not allowed with IRQ disabled are allowed while the
 116 * flag is set.
 117 */
 118bool early_boot_irqs_disabled __read_mostly;
 119
 120enum system_states system_state __read_mostly;
 121EXPORT_SYMBOL(system_state);
 122
 123/*
 124 * Boot command-line arguments
 125 */
 126#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
 127#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
 128
 129extern void time_init(void);
 130/* Default late time init is NULL. archs can override this later. */
 131void (*__initdata late_time_init)(void);
 132
 133/* Untouched command line saved by arch-specific code. */
 134char __initdata boot_command_line[COMMAND_LINE_SIZE];
 135/* Untouched saved command line (eg. for /proc) */
 136char *saved_command_line;
 137/* Command line for parameter parsing */
 138static char *static_command_line;
 139/* Command line for per-initcall parameter parsing */
 140static char *initcall_command_line;
 141
 142static char *execute_command;
 143static char *ramdisk_execute_command;
 144
 145/*
 146 * Used to generate warnings if static_key manipulation functions are used
 147 * before jump_label_init is called.
 148 */
 149bool static_key_initialized __read_mostly;
 150EXPORT_SYMBOL_GPL(static_key_initialized);
 151
 152/*
 153 * If set, this is an indication to the drivers that reset the underlying
 154 * device before going ahead with the initialization otherwise driver might
 155 * rely on the BIOS and skip the reset operation.
 156 *
 157 * This is useful if kernel is booting in an unreliable environment.
 158 * For ex. kdump situation where previous kernel has crashed, BIOS has been
 159 * skipped and devices will be in unknown state.
 160 */
 161unsigned int reset_devices;
 162EXPORT_SYMBOL(reset_devices);
 163
 164static int __init set_reset_devices(char *str)
 165{
 166        reset_devices = 1;
 167        return 1;
 168}
 169
 170__setup("reset_devices", set_reset_devices);
 171
 172static const char *argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 173const char *envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
 174static const char *panic_later, *panic_param;
 175
 176extern const struct obs_kernel_param __setup_start[], __setup_end[];
 177
 178static bool __init obsolete_checksetup(char *line)
 179{
 180        const struct obs_kernel_param *p;
 181        bool had_early_param = false;
 182
 183        p = __setup_start;
 184        do {
 185                int n = strlen(p->str);
 186                if (parameqn(line, p->str, n)) {
 187                        if (p->early) {
 188                                /* Already done in parse_early_param?
 189                                 * (Needs exact match on param part).
 190                                 * Keep iterating, as we can have early
 191                                 * params and __setups of same names 8( */
 192                                if (line[n] == '\0' || line[n] == '=')
 193                                        had_early_param = true;
 194                        } else if (!p->setup_func) {
 195                                pr_warn("Parameter %s is obsolete, ignored\n",
 196                                        p->str);
 197                                return true;
 198                        } else if (p->setup_func(line + n))
 199                                return true;
 200                }
 201                p++;
 202        } while (p < __setup_end);
 203
 204        return had_early_param;
 205}
 206
 207/*
 208 * This should be approx 2 Bo*oMips to start (note initial shift), and will
 209 * still work even if initially too large, it will just take slightly longer
 210 */
 211unsigned long loops_per_jiffy = (1<<12);
 212EXPORT_SYMBOL(loops_per_jiffy);
 213
 214static int __init debug_kernel(char *str)
 215{
 216        console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
 217        return 0;
 218}
 219
 220static int __init quiet_kernel(char *str)
 221{
 222        console_loglevel = CONSOLE_LOGLEVEL_QUIET;
 223        return 0;
 224}
 225
 226early_param("debug", debug_kernel);
 227early_param("quiet", quiet_kernel);
 228
 229static int __init loglevel(char *str)
 230{
 231        int newlevel;
 232
 233        /*
 234         * Only update loglevel value when a correct setting was passed,
 235         * to prevent blind crashes (when loglevel being set to 0) that
 236         * are quite hard to debug
 237         */
 238        if (get_option(&str, &newlevel)) {
 239                console_loglevel = newlevel;
 240                return 0;
 241        }
 242
 243        return -EINVAL;
 244}
 245
 246early_param("loglevel", loglevel);
 247
 248/* Change NUL term back to "=", to make "param" the whole string. */
 249static int __init repair_env_string(char *param, char *val,
 250                                    const char *unused, void *arg)
 251{
 252        if (val) {
 253                /* param=val or param="val"? */
 254                if (val == param+strlen(param)+1)
 255                        val[-1] = '=';
 256                else if (val == param+strlen(param)+2) {
 257                        val[-2] = '=';
 258                        memmove(val-1, val, strlen(val)+1);
 259                        val--;
 260                } else
 261                        BUG();
 262        }
 263        return 0;
 264}
 265
 266/* Anything after -- gets handed straight to init. */
 267static int __init set_init_arg(char *param, char *val,
 268                               const char *unused, void *arg)
 269{
 270        unsigned int i;
 271
 272        if (panic_later)
 273                return 0;
 274
 275        repair_env_string(param, val, unused, NULL);
 276
 277        for (i = 0; argv_init[i]; i++) {
 278                if (i == MAX_INIT_ARGS) {
 279                        panic_later = "init";
 280                        panic_param = param;
 281                        return 0;
 282                }
 283        }
 284        argv_init[i] = param;
 285        return 0;
 286}
 287
 288/*
 289 * Unknown boot options get handed to init, unless they look like
 290 * unused parameters (modprobe will find them in /proc/cmdline).
 291 */
 292static int __init unknown_bootoption(char *param, char *val,
 293                                     const char *unused, void *arg)
 294{
 295        repair_env_string(param, val, unused, NULL);
 296
 297        /* Handle obsolete-style parameters */
 298        if (obsolete_checksetup(param))
 299                return 0;
 300
 301        /* Unused module parameter. */
 302        if (strchr(param, '.') && (!val || strchr(param, '.') < val))
 303                return 0;
 304
 305        if (panic_later)
 306                return 0;
 307
 308        if (val) {
 309                /* Environment option */
 310                unsigned int i;
 311                for (i = 0; envp_init[i]; i++) {
 312                        if (i == MAX_INIT_ENVS) {
 313                                panic_later = "env";
 314                                panic_param = param;
 315                        }
 316                        if (!strncmp(param, envp_init[i], val - param))
 317                                break;
 318                }
 319                envp_init[i] = param;
 320        } else {
 321                /* Command line option */
 322                unsigned int i;
 323                for (i = 0; argv_init[i]; i++) {
 324                        if (i == MAX_INIT_ARGS) {
 325                                panic_later = "init";
 326                                panic_param = param;
 327                        }
 328                }
 329                argv_init[i] = param;
 330        }
 331        return 0;
 332}
 333
 334static int __init init_setup(char *str)
 335{
 336        unsigned int i;
 337
 338        execute_command = str;
 339        /*
 340         * In case LILO is going to boot us with default command line,
 341         * it prepends "auto" before the whole cmdline which makes
 342         * the shell think it should execute a script with such name.
 343         * So we ignore all arguments entered _before_ init=... [MJ]
 344         */
 345        for (i = 1; i < MAX_INIT_ARGS; i++)
 346                argv_init[i] = NULL;
 347        return 1;
 348}
 349__setup("init=", init_setup);
 350
 351static int __init rdinit_setup(char *str)
 352{
 353        unsigned int i;
 354
 355        ramdisk_execute_command = str;
 356        /* See "auto" comment in init_setup */
 357        for (i = 1; i < MAX_INIT_ARGS; i++)
 358                argv_init[i] = NULL;
 359        return 1;
 360}
 361__setup("rdinit=", rdinit_setup);
 362
 363#ifndef CONFIG_SMP
 364static const unsigned int setup_max_cpus = NR_CPUS;
 365static inline void setup_nr_cpu_ids(void) { }
 366static inline void smp_prepare_cpus(unsigned int maxcpus) { }
 367#endif
 368
 369/*
 370 * We need to store the untouched command line for future reference.
 371 * We also need to store the touched command line since the parameter
 372 * parsing is performed in place, and we should allow a component to
 373 * store reference of name/value for future reference.
 374 */
 375static void __init setup_command_line(char *command_line)
 376{
 377        size_t len = strlen(boot_command_line) + 1;
 378
 379        saved_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
 380        if (!saved_command_line)
 381                panic("%s: Failed to allocate %zu bytes\n", __func__, len);
 382
 383        initcall_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
 384        if (!initcall_command_line)
 385                panic("%s: Failed to allocate %zu bytes\n", __func__, len);
 386
 387        static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
 388        if (!static_command_line)
 389                panic("%s: Failed to allocate %zu bytes\n", __func__, len);
 390
 391        strcpy(saved_command_line, boot_command_line);
 392        strcpy(static_command_line, command_line);
 393}
 394
 395/*
 396 * We need to finalize in a non-__init function or else race conditions
 397 * between the root thread and the init thread may cause start_kernel to
 398 * be reaped by free_initmem before the root thread has proceeded to
 399 * cpu_idle.
 400 *
 401 * gcc-3.4 accidentally inlines this function, so use noinline.
 402 */
 403
 404static __initdata DECLARE_COMPLETION(kthreadd_done);
 405
 406noinline void __ref rest_init(void)
 407{
 408        struct task_struct *tsk;
 409        int pid;
 410
 411        rcu_scheduler_starting();
 412        /*
 413         * We need to spawn init first so that it obtains pid 1, however
 414         * the init task will end up wanting to create kthreads, which, if
 415         * we schedule it before we create kthreadd, will OOPS.
 416         */
 417        pid = kernel_thread(kernel_init, NULL, CLONE_FS);
 418        /*
 419         * Pin init on the boot CPU. Task migration is not properly working
 420         * until sched_init_smp() has been run. It will set the allowed
 421         * CPUs for init to the non isolated CPUs.
 422         */
 423        rcu_read_lock();
 424        tsk = find_task_by_pid_ns(pid, &init_pid_ns);
 425        set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
 426        rcu_read_unlock();
 427
 428        numa_default_policy();
 429        pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
 430        rcu_read_lock();
 431        kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
 432        rcu_read_unlock();
 433
 434        /*
 435         * Enable might_sleep() and smp_processor_id() checks.
 436         * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
 437         * kernel_thread() would trigger might_sleep() splats. With
 438         * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
 439         * already, but it's stuck on the kthreadd_done completion.
 440         */
 441        system_state = SYSTEM_SCHEDULING;
 442
 443        complete(&kthreadd_done);
 444
 445        /*
 446         * The boot idle thread must execute schedule()
 447         * at least once to get things moving:
 448         */
 449        schedule_preempt_disabled();
 450        /* Call into cpu_idle with preempt disabled */
 451        cpu_startup_entry(CPUHP_ONLINE);
 452}
 453
 454/* Check for early params. */
 455static int __init do_early_param(char *param, char *val,
 456                                 const char *unused, void *arg)
 457{
 458        const struct obs_kernel_param *p;
 459
 460        for (p = __setup_start; p < __setup_end; p++) {
 461                if ((p->early && parameq(param, p->str)) ||
 462                    (strcmp(param, "console") == 0 &&
 463                     strcmp(p->str, "earlycon") == 0)
 464                ) {
 465                        if (p->setup_func(val) != 0)
 466                                pr_warn("Malformed early option '%s'\n", param);
 467                }
 468        }
 469        /* We accept everything at this stage. */
 470        return 0;
 471}
 472
 473void __init parse_early_options(char *cmdline)
 474{
 475        parse_args("early options", cmdline, NULL, 0, 0, 0, NULL,
 476                   do_early_param);
 477}
 478
 479/* Arch code calls this early on, or if not, just before other parsing. */
 480void __init parse_early_param(void)
 481{
 482        static int done __initdata;
 483        static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
 484
 485        if (done)
 486                return;
 487
 488        /* All fall through to do_early_param. */
 489        strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
 490        parse_early_options(tmp_cmdline);
 491        done = 1;
 492}
 493
 494void __init __weak arch_post_acpi_subsys_init(void) { }
 495
 496void __init __weak smp_setup_processor_id(void)
 497{
 498}
 499
 500# if THREAD_SIZE >= PAGE_SIZE
 501void __init __weak thread_stack_cache_init(void)
 502{
 503}
 504#endif
 505
 506void __init __weak mem_encrypt_init(void) { }
 507
 508void __init __weak poking_init(void) { }
 509
 510void __init __weak pgtable_cache_init(void) { }
 511
 512bool initcall_debug;
 513core_param(initcall_debug, initcall_debug, bool, 0644);
 514
 515#ifdef TRACEPOINTS_ENABLED
 516static void __init initcall_debug_enable(void);
 517#else
 518static inline void initcall_debug_enable(void)
 519{
 520}
 521#endif
 522
 523/* Report memory auto-initialization states for this boot. */
 524static void __init report_meminit(void)
 525{
 526        const char *stack;
 527
 528        if (IS_ENABLED(CONFIG_INIT_STACK_ALL))
 529                stack = "all";
 530        else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL))
 531                stack = "byref_all";
 532        else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF))
 533                stack = "byref";
 534        else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER))
 535                stack = "__user";
 536        else
 537                stack = "off";
 538
 539        pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n",
 540                stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off",
 541                want_init_on_free() ? "on" : "off");
 542        if (want_init_on_free())
 543                pr_info("mem auto-init: clearing system memory may take some time...\n");
 544}
 545
 546/*
 547 * Set up kernel memory allocators
 548 */
 549static void __init mm_init(void)
 550{
 551        /*
 552         * page_ext requires contiguous pages,
 553         * bigger than MAX_ORDER unless SPARSEMEM.
 554         */
 555        page_ext_init_flatmem();
 556        report_meminit();
 557        mem_init();
 558        kmem_cache_init();
 559        kmemleak_init();
 560        pgtable_init();
 561        debug_objects_mem_init();
 562        vmalloc_init();
 563        ioremap_huge_init();
 564        /* Should be run before the first non-init thread is created */
 565        init_espfix_bsp();
 566        /* Should be run after espfix64 is set up. */
 567        pti_init();
 568}
 569
 570void __init __weak arch_call_rest_init(void)
 571{
 572        rest_init();
 573}
 574
 575asmlinkage __visible void __init start_kernel(void)
 576{
 577        char *command_line;
 578        char *after_dashes;
 579
 580        set_task_stack_end_magic(&init_task);
 581        smp_setup_processor_id();
 582        debug_objects_early_init();
 583
 584        cgroup_init_early();
 585
 586        local_irq_disable();
 587        early_boot_irqs_disabled = true;
 588
 589        /*
 590         * Interrupts are still disabled. Do necessary setups, then
 591         * enable them.
 592         */
 593        boot_cpu_init();
 594        page_address_init();
 595        pr_notice("%s", linux_banner);
 596        early_security_init();
 597        setup_arch(&command_line);
 598        setup_command_line(command_line);
 599        setup_nr_cpu_ids();
 600        setup_per_cpu_areas();
 601        smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
 602        boot_cpu_hotplug_init();
 603
 604        build_all_zonelists(NULL);
 605        page_alloc_init();
 606
 607        pr_notice("Kernel command line: %s\n", boot_command_line);
 608        /* parameters may set static keys */
 609        jump_label_init();
 610        parse_early_param();
 611        after_dashes = parse_args("Booting kernel",
 612                                  static_command_line, __start___param,
 613                                  __stop___param - __start___param,
 614                                  -1, -1, NULL, &unknown_bootoption);
 615        if (!IS_ERR_OR_NULL(after_dashes))
 616                parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
 617                           NULL, set_init_arg);
 618
 619        /*
 620         * These use large bootmem allocations and must precede
 621         * kmem_cache_init()
 622         */
 623        setup_log_buf(0);
 624        vfs_caches_init_early();
 625        sort_main_extable();
 626        trap_init();
 627        mm_init();
 628
 629        ftrace_init();
 630
 631        /* trace_printk can be enabled here */
 632        early_trace_init();
 633
 634        /*
 635         * Set up the scheduler prior starting any interrupts (such as the
 636         * timer interrupt). Full topology setup happens at smp_init()
 637         * time - but meanwhile we still have a functioning scheduler.
 638         */
 639        sched_init();
 640        /*
 641         * Disable preemption - early bootup scheduling is extremely
 642         * fragile until we cpu_idle() for the first time.
 643         */
 644        preempt_disable();
 645        if (WARN(!irqs_disabled(),
 646                 "Interrupts were enabled *very* early, fixing it\n"))
 647                local_irq_disable();
 648        radix_tree_init();
 649
 650        /*
 651         * Set up housekeeping before setting up workqueues to allow the unbound
 652         * workqueue to take non-housekeeping into account.
 653         */
 654        housekeeping_init();
 655
 656        /*
 657         * Allow workqueue creation and work item queueing/cancelling
 658         * early.  Work item execution depends on kthreads and starts after
 659         * workqueue_init().
 660         */
 661        workqueue_init_early();
 662
 663        rcu_init();
 664
 665        /* Trace events are available after this */
 666        trace_init();
 667
 668        if (initcall_debug)
 669                initcall_debug_enable();
 670
 671        context_tracking_init();
 672        /* init some links before init_ISA_irqs() */
 673        early_irq_init();
 674        init_IRQ();
 675        tick_init();
 676        rcu_init_nohz();
 677        init_timers();
 678        hrtimers_init();
 679        softirq_init();
 680        timekeeping_init();
 681
 682        /*
 683         * For best initial stack canary entropy, prepare it after:
 684         * - setup_arch() for any UEFI RNG entropy and boot cmdline access
 685         * - timekeeping_init() for ktime entropy used in rand_initialize()
 686         * - rand_initialize() to get any arch-specific entropy like RDRAND
 687         * - add_latent_entropy() to get any latent entropy
 688         * - adding command line entropy
 689         */
 690        rand_initialize();
 691        add_latent_entropy();
 692        add_device_randomness(command_line, strlen(command_line));
 693        boot_init_stack_canary();
 694
 695        time_init();
 696        printk_safe_init();
 697        perf_event_init();
 698        profile_init();
 699        call_function_init();
 700        WARN(!irqs_disabled(), "Interrupts were enabled early\n");
 701
 702        early_boot_irqs_disabled = false;
 703        local_irq_enable();
 704
 705        kmem_cache_init_late();
 706
 707        /*
 708         * HACK ALERT! This is early. We're enabling the console before
 709         * we've done PCI setups etc, and console_init() must be aware of
 710         * this. But we do want output early, in case something goes wrong.
 711         */
 712        console_init();
 713        if (panic_later)
 714                panic("Too many boot %s vars at `%s'", panic_later,
 715                      panic_param);
 716
 717        lockdep_init();
 718
 719        /*
 720         * Need to run this when irqs are enabled, because it wants
 721         * to self-test [hard/soft]-irqs on/off lock inversion bugs
 722         * too:
 723         */
 724        locking_selftest();
 725
 726        /*
 727         * This needs to be called before any devices perform DMA
 728         * operations that might use the SWIOTLB bounce buffers. It will
 729         * mark the bounce buffers as decrypted so that their usage will
 730         * not cause "plain-text" data to be decrypted when accessed.
 731         */
 732        mem_encrypt_init();
 733
 734#ifdef CONFIG_BLK_DEV_INITRD
 735        if (initrd_start && !initrd_below_start_ok &&
 736            page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
 737                pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
 738                    page_to_pfn(virt_to_page((void *)initrd_start)),
 739                    min_low_pfn);
 740                initrd_start = 0;
 741        }
 742#endif
 743        setup_per_cpu_pageset();
 744        numa_policy_init();
 745        acpi_early_init();
 746        if (late_time_init)
 747                late_time_init();
 748        sched_clock_init();
 749        calibrate_delay();
 750        pid_idr_init();
 751        anon_vma_init();
 752#ifdef CONFIG_X86
 753        if (efi_enabled(EFI_RUNTIME_SERVICES))
 754                efi_enter_virtual_mode();
 755#endif
 756        thread_stack_cache_init();
 757        cred_init();
 758        fork_init();
 759        proc_caches_init();
 760        uts_ns_init();
 761        buffer_init();
 762        key_init();
 763        security_init();
 764        dbg_late_init();
 765        vfs_caches_init();
 766        pagecache_init();
 767        signals_init();
 768        seq_file_init();
 769        proc_root_init();
 770        nsfs_init();
 771        cpuset_init();
 772        cgroup_init();
 773        taskstats_init_early();
 774        delayacct_init();
 775
 776        poking_init();
 777        check_bugs();
 778
 779        acpi_subsystem_init();
 780        arch_post_acpi_subsys_init();
 781        sfi_init_late();
 782
 783        /* Do the rest non-__init'ed, we're now alive */
 784        arch_call_rest_init();
 785}
 786
 787/* Call all constructor functions linked into the kernel. */
 788static void __init do_ctors(void)
 789{
 790#ifdef CONFIG_CONSTRUCTORS
 791        ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
 792
 793        for (; fn < (ctor_fn_t *) __ctors_end; fn++)
 794                (*fn)();
 795#endif
 796}
 797
 798#ifdef CONFIG_KALLSYMS
 799struct blacklist_entry {
 800        struct list_head next;
 801        char *buf;
 802};
 803
 804static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
 805
 806static int __init initcall_blacklist(char *str)
 807{
 808        char *str_entry;
 809        struct blacklist_entry *entry;
 810
 811        /* str argument is a comma-separated list of functions */
 812        do {
 813                str_entry = strsep(&str, ",");
 814                if (str_entry) {
 815                        pr_debug("blacklisting initcall %s\n", str_entry);
 816                        entry = memblock_alloc(sizeof(*entry),
 817                                               SMP_CACHE_BYTES);
 818                        if (!entry)
 819                                panic("%s: Failed to allocate %zu bytes\n",
 820                                      __func__, sizeof(*entry));
 821                        entry->buf = memblock_alloc(strlen(str_entry) + 1,
 822                                                    SMP_CACHE_BYTES);
 823                        if (!entry->buf)
 824                                panic("%s: Failed to allocate %zu bytes\n",
 825                                      __func__, strlen(str_entry) + 1);
 826                        strcpy(entry->buf, str_entry);
 827                        list_add(&entry->next, &blacklisted_initcalls);
 828                }
 829        } while (str_entry);
 830
 831        return 0;
 832}
 833
 834static bool __init_or_module initcall_blacklisted(initcall_t fn)
 835{
 836        struct blacklist_entry *entry;
 837        char fn_name[KSYM_SYMBOL_LEN];
 838        unsigned long addr;
 839
 840        if (list_empty(&blacklisted_initcalls))
 841                return false;
 842
 843        addr = (unsigned long) dereference_function_descriptor(fn);
 844        sprint_symbol_no_offset(fn_name, addr);
 845
 846        /*
 847         * fn will be "function_name [module_name]" where [module_name] is not
 848         * displayed for built-in init functions.  Strip off the [module_name].
 849         */
 850        strreplace(fn_name, ' ', '\0');
 851
 852        list_for_each_entry(entry, &blacklisted_initcalls, next) {
 853                if (!strcmp(fn_name, entry->buf)) {
 854                        pr_debug("initcall %s blacklisted\n", fn_name);
 855                        return true;
 856                }
 857        }
 858
 859        return false;
 860}
 861#else
 862static int __init initcall_blacklist(char *str)
 863{
 864        pr_warn("initcall_blacklist requires CONFIG_KALLSYMS\n");
 865        return 0;
 866}
 867
 868static bool __init_or_module initcall_blacklisted(initcall_t fn)
 869{
 870        return false;
 871}
 872#endif
 873__setup("initcall_blacklist=", initcall_blacklist);
 874
 875static __init_or_module void
 876trace_initcall_start_cb(void *data, initcall_t fn)
 877{
 878        ktime_t *calltime = (ktime_t *)data;
 879
 880        printk(KERN_DEBUG "calling  %pS @ %i\n", fn, task_pid_nr(current));
 881        *calltime = ktime_get();
 882}
 883
 884static __init_or_module void
 885trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
 886{
 887        ktime_t *calltime = (ktime_t *)data;
 888        ktime_t delta, rettime;
 889        unsigned long long duration;
 890
 891        rettime = ktime_get();
 892        delta = ktime_sub(rettime, *calltime);
 893        duration = (unsigned long long) ktime_to_ns(delta) >> 10;
 894        printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
 895                 fn, ret, duration);
 896}
 897
 898static ktime_t initcall_calltime;
 899
 900#ifdef TRACEPOINTS_ENABLED
 901static void __init initcall_debug_enable(void)
 902{
 903        int ret;
 904
 905        ret = register_trace_initcall_start(trace_initcall_start_cb,
 906                                            &initcall_calltime);
 907        ret |= register_trace_initcall_finish(trace_initcall_finish_cb,
 908                                              &initcall_calltime);
 909        WARN(ret, "Failed to register initcall tracepoints\n");
 910}
 911# define do_trace_initcall_start        trace_initcall_start
 912# define do_trace_initcall_finish       trace_initcall_finish
 913#else
 914static inline void do_trace_initcall_start(initcall_t fn)
 915{
 916        if (!initcall_debug)
 917                return;
 918        trace_initcall_start_cb(&initcall_calltime, fn);
 919}
 920static inline void do_trace_initcall_finish(initcall_t fn, int ret)
 921{
 922        if (!initcall_debug)
 923                return;
 924        trace_initcall_finish_cb(&initcall_calltime, fn, ret);
 925}
 926#endif /* !TRACEPOINTS_ENABLED */
 927
 928int __init_or_module do_one_initcall(initcall_t fn)
 929{
 930        int count = preempt_count();
 931        char msgbuf[64];
 932        int ret;
 933
 934        if (initcall_blacklisted(fn))
 935                return -EPERM;
 936
 937        do_trace_initcall_start(fn);
 938        ret = fn();
 939        do_trace_initcall_finish(fn, ret);
 940
 941        msgbuf[0] = 0;
 942
 943        if (preempt_count() != count) {
 944                sprintf(msgbuf, "preemption imbalance ");
 945                preempt_count_set(count);
 946        }
 947        if (irqs_disabled()) {
 948                strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
 949                local_irq_enable();
 950        }
 951        WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
 952
 953        add_latent_entropy();
 954        return ret;
 955}
 956
 957
 958extern initcall_entry_t __initcall_start[];
 959extern initcall_entry_t __initcall0_start[];
 960extern initcall_entry_t __initcall1_start[];
 961extern initcall_entry_t __initcall2_start[];
 962extern initcall_entry_t __initcall3_start[];
 963extern initcall_entry_t __initcall4_start[];
 964extern initcall_entry_t __initcall5_start[];
 965extern initcall_entry_t __initcall6_start[];
 966extern initcall_entry_t __initcall7_start[];
 967extern initcall_entry_t __initcall_end[];
 968
 969static initcall_entry_t *initcall_levels[] __initdata = {
 970        __initcall0_start,
 971        __initcall1_start,
 972        __initcall2_start,
 973        __initcall3_start,
 974        __initcall4_start,
 975        __initcall5_start,
 976        __initcall6_start,
 977        __initcall7_start,
 978        __initcall_end,
 979};
 980
 981/* Keep these in sync with initcalls in include/linux/init.h */
 982static const char *initcall_level_names[] __initdata = {
 983        "pure",
 984        "core",
 985        "postcore",
 986        "arch",
 987        "subsys",
 988        "fs",
 989        "device",
 990        "late",
 991};
 992
 993static void __init do_initcall_level(int level)
 994{
 995        initcall_entry_t *fn;
 996
 997        strcpy(initcall_command_line, saved_command_line);
 998        parse_args(initcall_level_names[level],
 999                   initcall_command_line, __start___param,
1000                   __stop___param - __start___param,
1001                   level, level,
1002                   NULL, &repair_env_string);
1003
1004        trace_initcall_level(initcall_level_names[level]);
1005        for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
1006                do_one_initcall(initcall_from_entry(fn));
1007}
1008
1009static void __init do_initcalls(void)
1010{
1011        int level;
1012
1013        for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
1014                do_initcall_level(level);
1015}
1016
1017/*
1018 * Ok, the machine is now initialized. None of the devices
1019 * have been touched yet, but the CPU subsystem is up and
1020 * running, and memory and process management works.
1021 *
1022 * Now we can finally start doing some real work..
1023 */
1024static void __init do_basic_setup(void)
1025{
1026        cpuset_init_smp();
1027        driver_init();
1028        init_irq_proc();
1029        do_ctors();
1030        usermodehelper_enable();
1031        do_initcalls();
1032}
1033
1034static void __init do_pre_smp_initcalls(void)
1035{
1036        initcall_entry_t *fn;
1037
1038        trace_initcall_level("early");
1039        for (fn = __initcall_start; fn < __initcall0_start; fn++)
1040                do_one_initcall(initcall_from_entry(fn));
1041}
1042
1043static int run_init_process(const char *init_filename)
1044{
1045        argv_init[0] = init_filename;
1046        pr_info("Run %s as init process\n", init_filename);
1047        return do_execve(getname_kernel(init_filename),
1048                (const char __user *const __user *)argv_init,
1049                (const char __user *const __user *)envp_init);
1050}
1051
1052static int try_to_run_init_process(const char *init_filename)
1053{
1054        int ret;
1055
1056        ret = run_init_process(init_filename);
1057
1058        if (ret && ret != -ENOENT) {
1059                pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
1060                       init_filename, ret);
1061        }
1062
1063        return ret;
1064}
1065
1066static noinline void __init kernel_init_freeable(void);
1067
1068#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
1069bool rodata_enabled __ro_after_init = true;
1070static int __init set_debug_rodata(char *str)
1071{
1072        return strtobool(str, &rodata_enabled);
1073}
1074__setup("rodata=", set_debug_rodata);
1075#endif
1076
1077#ifdef CONFIG_STRICT_KERNEL_RWX
1078static void mark_readonly(void)
1079{
1080        if (rodata_enabled) {
1081                /*
1082                 * load_module() results in W+X mappings, which are cleaned
1083                 * up with call_rcu().  Let's make sure that queued work is
1084                 * flushed so that we don't hit false positives looking for
1085                 * insecure pages which are W+X.
1086                 */
1087                rcu_barrier();
1088                mark_rodata_ro();
1089                rodata_test();
1090        } else
1091                pr_info("Kernel memory protection disabled.\n");
1092}
1093#else
1094static inline void mark_readonly(void)
1095{
1096        pr_warn("This architecture does not have kernel memory protection.\n");
1097}
1098#endif
1099
1100void __weak free_initmem(void)
1101{
1102        free_initmem_default(POISON_FREE_INITMEM);
1103}
1104
1105static int __ref kernel_init(void *unused)
1106{
1107        int ret;
1108
1109        kernel_init_freeable();
1110        /* need to finish all async __init code before freeing the memory */
1111        async_synchronize_full();
1112        ftrace_free_init_mem();
1113        free_initmem();
1114        mark_readonly();
1115
1116        /*
1117         * Kernel mappings are now finalized - update the userspace page-table
1118         * to finalize PTI.
1119         */
1120        pti_finalize();
1121
1122        system_state = SYSTEM_RUNNING;
1123        numa_default_policy();
1124
1125        rcu_end_inkernel_boot();
1126
1127        if (ramdisk_execute_command) {
1128                ret = run_init_process(ramdisk_execute_command);
1129                if (!ret)
1130                        return 0;
1131                pr_err("Failed to execute %s (error %d)\n",
1132                       ramdisk_execute_command, ret);
1133        }
1134
1135        /*
1136         * We try each of these until one succeeds.
1137         *
1138         * The Bourne shell can be used instead of init if we are
1139         * trying to recover a really broken machine.
1140         */
1141        if (execute_command) {
1142                ret = run_init_process(execute_command);
1143                if (!ret)
1144                        return 0;
1145                panic("Requested init %s failed (error %d).",
1146                      execute_command, ret);
1147        }
1148        if (!try_to_run_init_process("/sbin/init") ||
1149            !try_to_run_init_process("/etc/init") ||
1150            !try_to_run_init_process("/bin/init") ||
1151            !try_to_run_init_process("/bin/sh"))
1152                return 0;
1153
1154        panic("No working init found.  Try passing init= option to kernel. "
1155              "See Linux Documentation/admin-guide/init.rst for guidance.");
1156}
1157
1158static noinline void __init kernel_init_freeable(void)
1159{
1160        /*
1161         * Wait until kthreadd is all set-up.
1162         */
1163        wait_for_completion(&kthreadd_done);
1164
1165        /* Now the scheduler is fully set up and can do blocking allocations */
1166        gfp_allowed_mask = __GFP_BITS_MASK;
1167
1168        /*
1169         * init can allocate pages on any node
1170         */
1171        set_mems_allowed(node_states[N_MEMORY]);
1172
1173        cad_pid = task_pid(current);
1174
1175        smp_prepare_cpus(setup_max_cpus);
1176
1177        workqueue_init();
1178
1179        init_mm_internals();
1180
1181        do_pre_smp_initcalls();
1182        lockup_detector_init();
1183
1184        smp_init();
1185        sched_init_smp();
1186
1187        page_alloc_init_late();
1188        /* Initialize page ext after all struct pages are initialized. */
1189        page_ext_init();
1190
1191        do_basic_setup();
1192
1193        /* Open the /dev/console on the rootfs, this should never fail */
1194        if (ksys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
1195                pr_err("Warning: unable to open an initial console.\n");
1196
1197        (void) ksys_dup(0);
1198        (void) ksys_dup(0);
1199        /*
1200         * check if there is an early userspace init.  If yes, let it do all
1201         * the work
1202         */
1203
1204        if (!ramdisk_execute_command)
1205                ramdisk_execute_command = "/init";
1206
1207        if (ksys_access((const char __user *)
1208                        ramdisk_execute_command, 0) != 0) {
1209                ramdisk_execute_command = NULL;
1210                prepare_namespace();
1211        }
1212
1213        /*
1214         * Ok, we have completed the initial bootup, and
1215         * we're essentially up and running. Get rid of the
1216         * initmem segments and start the user-mode stuff..
1217         *
1218         * rootfs is available now, try loading the public keys
1219         * and default modules
1220         */
1221
1222        integrity_load_keys();
1223}
1224