Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

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();
+}