Merge tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linuxgrafted

Pull io_uring fixes from Jens Axboe:

 - Fix a task_work add use-after-free with SQPOLL.

   The sqpoll thread could pop and complete the last request while
   io_req_normal_work_add() was still looking at them after the mpscq
   push.

   Use the same approach as DEFER_TASKRUN to protect from that, holding
   an RCU read lock across the add, and have exit wait for an RCU grace
   period for SQPOLL rings as well.

 - CQE32 ring fixes: correct the free entry check for 32b CQEs, zero the
   big_cqe for aux CQEs, and only post the dummy skip CQE on CQE_MIXED
   rings

 - Mark the source filter table as COW when cloning bpf filters, so
   registering another filter on the source doesn't modify the shared
   table in place

 - Initialize the task context before running the BPF loop

 - Requeue zcrx multishot receives stopped by a local resource

 - End a TX_TIMESTAMP multishot cmd when the CQ is full (lollipopkit)

* tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring: fix task_work add use-after-free with SQPOLL
  io_uring/cmd_net: end TX_TIMESTAMP multishot when the CQ is full
  io_uring/zcrx: requeue multishot receives stopped by a local resource
  io_uring: initialize task context before running the BPF loop
  io_uring: zero big_cqe for aux CQEs on CQE32 rings
  io_uring: fix free entry check for 32b CQEs on CQE32 rings
  io_uring: only post the dummy skip CQE on CQE_MIXED rings
  io_uring/bpf_filter: mark source as COW when cloning filters

1 files changed, 1706 insertions, 0 deletions

diff --git a/init/main.c b/init/main.c
new file mode 100644
index 000000000..31f2bf549
--- /dev/null
+++ b/init/main.c
@@ -0,0 +1,1706 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/init/main.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  GK 2/5/95  -  Changed to support mounting root fs via NFS
+ *  Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
+ *  Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
+ *  Simplified starting of init:  Michael A. Griffith <grif@acm.org>
+ */
+
+#define DEBUG		/* Enable initcall_debug */
+
+#include <linux/types.h>
+#include <linux/export.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/memblock.h>
+#include <linux/acpi.h>
+#include <linux/bootconfig.h>
+#include <linux/console.h>
+#include <linux/nmi.h>
+#include <linux/percpu.h>
+#include <linux/kmod.h>
+#include <linux/kprobes.h>
+#include <linux/kmsan.h>
+#include <linux/ksysfs.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/kfence.h>
+#include <linux/rcupdate.h>
+#include <linux/srcu.h>
+#include <linux/moduleparam.h>
+#include <linux/kallsyms.h>
+#include <linux/buildid.h>
+#include <linux/writeback.h>
+#include <linux/cpu.h>
+#include <linux/cpuset.h>
+#include <linux/memcontrol.h>
+#include <linux/cgroup.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/debug_locks.h>
+#include <linux/debugobjects.h>
+#include <linux/lockdep.h>
+#include <linux/kmemleak.h>
+#include <linux/padata.h>
+#include <linux/pid_namespace.h>
+#include <linux/device/driver.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/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/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/moduleloader.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/kcsan.h>
+#include <linux/init_syscalls.h>
+#include <linux/stackdepot.h>
+#include <linux/randomize_kstack.h>
+#include <linux/pidfs.h>
+#include <linux/fs_struct.h>
+#include <linux/ptdump.h>
+#include <linux/time_namespace.h>
+#include <linux/unaligned.h>
+#include <linux/vdso_datastore.h>
+#include <net/net_namespace.h>
+
+#include <asm/io.h>
+#include <asm/setup.h>
+#include <asm/sections.h>
+#include <asm/cacheflush.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/initcall.h>
+
+#include <kunit/test.h>
+
+static int kernel_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
+
+/* 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 __ro_after_init;
+unsigned int saved_command_line_len __ro_after_init;
+/* Command line for parameter parsing */
+static char *static_command_line;
+/* Untouched extra command line */
+static char *extra_command_line;
+/* Extra init arguments */
+static char *extra_init_args;
+
+#ifdef CONFIG_BOOT_CONFIG
+/* Is bootconfig on command line? */
+static bool bootconfig_found;
+static size_t initargs_offs;
+#else
+# define bootconfig_found false
+# define initargs_offs 0
+#endif
+
+static char *execute_command;
+static char *ramdisk_execute_command = "/init";
+static bool __initdata ramdisk_execute_command_set;
+
+/*
+ * 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;
+
+static bool __init obsolete_checksetup(char *line)
+{
+	const struct obs_kernel_param *p;
+	bool had_early_param = false;
+
+	p = __setup_start;
+	do {
+		int n = strlen(p->str);
+		if (parameqn(line, p->str, n)) {
+			if (p->early) {
+				/* Already done in parse_early_param?
+				 * (Needs exact match on param part).
+				 * Keep iterating, as we can have early
+				 * params and __setups of same names 8( */
+				if (line[n] == '\0' || line[n] == '=')
+					had_early_param = true;
+			} else if (!p->setup_func) {
+				pr_warn("Parameter %s is obsolete, ignored\n",
+					p->str);
+				return true;
+			} else if (p->setup_func(line + n))
+				return true;
+		}
+		p++;
+	} while (p < __setup_end);
+
+	return had_early_param;
+}
+
+/*
+ * This should be approx 2 Bo*oMips to start (note initial shift), and will
+ * still work even if initially too large, it will just take slightly longer
+ */
+unsigned long loops_per_jiffy = (1<<12);
+EXPORT_SYMBOL(loops_per_jiffy);
+
+static int __init debug_kernel(char *str)
+{
+	console_loglevel = CONSOLE_LOGLEVEL_DEBUG;
+	return 0;
+}
+
+static int __init quiet_kernel(char *str)
+{
+	console_loglevel = CONSOLE_LOGLEVEL_QUIET;
+	return 0;
+}
+
+early_param("debug", debug_kernel);
+early_param("quiet", quiet_kernel);
+
+static int __init loglevel(char *str)
+{
+	int newlevel;
+
+	/*
+	 * Only update loglevel value when a correct setting was passed,
+	 * to prevent blind crashes (when loglevel being set to 0) that
+	 * are quite hard to debug
+	 */
+	if (get_option(&str, &newlevel)) {
+		console_loglevel = newlevel;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+early_param("loglevel", loglevel);
+
+#ifdef CONFIG_BLK_DEV_INITRD
+static void * __init get_boot_config_from_initrd(size_t *_size)
+{
+	u32 size, csum;
+	char *data;
+	u8 *hdr;
+	int i;
+
+	if (!initrd_end || initrd_end < initrd_start ||
+	    initrd_end - initrd_start < BOOTCONFIG_MAGIC_LEN + 8)
+		return NULL;
+
+	data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
+	/*
+	 * Since Grub may align the size of initrd to 4, we must
+	 * check the preceding 3 bytes as well.
+	 */
+	for (i = 0; i < 4; i++) {
+		if (!memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
+			goto found;
+		data--;
+	}
+	return NULL;
+
+found:
+	hdr = (u8 *)(data - 8);
+	if ((unsigned long)hdr < initrd_start)
+		return NULL;
+
+	size = get_unaligned_le32(hdr);
+	csum = get_unaligned_le32(hdr + 4);
+
+	if (size > XBC_DATA_MAX) {
+		pr_err("bootconfig size %u is greater than max size %d\n",
+			size, XBC_DATA_MAX);
+		return NULL;
+	}
+
+	if (size > ((unsigned long)hdr - initrd_start)) {
+		pr_err("bootconfig size %u is greater than initrd size %lu\n",
+			size, initrd_end - initrd_start);
+		return NULL;
+	}
+
+	data = ((void *)hdr) - size;
+
+	if (xbc_calc_checksum(data, size) != csum) {
+		pr_err("bootconfig checksum failed\n");
+		return NULL;
+	}
+
+	/* Remove bootconfig from initramfs/initrd */
+	initrd_end = (unsigned long)data;
+	if (_size)
+		*_size = size;
+
+	return data;
+}
+#else
+static void * __init get_boot_config_from_initrd(size_t *_size)
+{
+	return NULL;
+}
+#endif
+
+#ifdef CONFIG_BOOT_CONFIG
+
+/* Make an extra command line under given key word */
+static char * __init xbc_make_cmdline(const char *key)
+{
+	struct xbc_node *root;
+	char *new_cmdline;
+	int ret, len = 0;
+
+	root = xbc_find_node(key);
+	if (!root)
+		return NULL;
+
+	/* Count required buffer size */
+	len = xbc_snprint_cmdline(NULL, 0, root);
+	if (len <= 0)
+		return NULL;
+
+	new_cmdline = memblock_alloc(len + 1, SMP_CACHE_BYTES);
+	if (!new_cmdline) {
+		pr_err("Failed to allocate memory for extra kernel cmdline.\n");
+		return NULL;
+	}
+
+	ret = xbc_snprint_cmdline(new_cmdline, len + 1, root);
+	if (ret < 0 || ret > len) {
+		pr_err("Failed to print extra kernel cmdline.\n");
+		memblock_free(new_cmdline, len + 1);
+		return NULL;
+	}
+
+	return new_cmdline;
+}
+
+static int __init warn_bootconfig(char *str)
+{
+	/* The 'bootconfig' option is handled by setup_boot_config(). */
+	return 0;
+}
+
+static void __init setup_boot_config(void)
+{
+	const char *msg, *data;
+	int pos, ret, offs;
+	size_t size;
+	bool from_embedded = false;
+
+	/* Cut out the bootconfig data even if we have no bootconfig option */
+	data = get_boot_config_from_initrd(&size);
+	/* If there is no bootconfig in initrd, try embedded one. */
+	if (!data) {
+		data = xbc_get_embedded_bootconfig(&size);
+		from_embedded = true;
+	}
+
+	bootconfig_found = bootconfig_cmdline_requested(boot_command_line, &offs);
+	if (!(bootconfig_found || IS_ENABLED(CONFIG_BOOT_CONFIG_FORCE)))
+		return;
+
+	/* Offset of the init arguments after a "--", located by the helper. */
+	initargs_offs = offs;
+
+	if (!data) {
+		/* If user intended to use bootconfig, show an error level message */
+		if (bootconfig_found)
+			pr_err("'bootconfig' found on command line, but no bootconfig found\n");
+		else
+			pr_info("No bootconfig data provided, so skipping bootconfig");
+		return;
+	}
+
+	ret = xbc_init(data, size, &msg, &pos);
+	if (ret < 0) {
+		if (pos < 0)
+			pr_err("Failed to init bootconfig: %s.\n", msg);
+		else
+			pr_err("Failed to parse bootconfig: %s at %d.\n",
+				msg, pos);
+	} else {
+		xbc_get_info(&ret, NULL);
+		pr_info("Load bootconfig: %ld bytes %d nodes\n", (long)size, ret);
+		/*
+		 * keys starting with "kernel." are passed via cmdline. When
+		 * this bootconfig came from the embedded source and
+		 * setup_arch() already prepended the rendered "kernel" subtree
+		 * to boot_command_line, rendering again here would duplicate
+		 * the keys in saved_command_line and make accumulating handlers
+		 * (console=, earlycon=, ...) re-register the same value. Skip
+		 * only when the prepend really happened.
+		 *
+		 * On arches that do not select ARCH_SUPPORTS_CMDLINE_FROM_BOOTCONFIG,
+		 * CONFIG_CMDLINE_FROM_BOOTCONFIG is unselectable and
+		 * xbc_embedded_cmdline_applied() collapses to a stub returning
+		 * false, so this path still runs and the embedded "kernel"
+		 * keys reach the cmdline via the runtime parser exactly as
+		 * before this series.
+		 */
+		if (!from_embedded || !xbc_embedded_cmdline_applied())
+			extra_command_line = xbc_make_cmdline("kernel");
+		/* Also, "init." keys are init arguments */
+		extra_init_args = xbc_make_cmdline("init");
+	}
+	return;
+}
+
+static void __init exit_boot_config(void)
+{
+	xbc_exit();
+}
+
+#else	/* !CONFIG_BOOT_CONFIG */
+
+static void __init setup_boot_config(void)
+{
+	/* Remove bootconfig data from initrd */
+	get_boot_config_from_initrd(NULL);
+}
+
+static int __init warn_bootconfig(char *str)
+{
+	pr_warn("WARNING: 'bootconfig' found on the kernel command line but CONFIG_BOOT_CONFIG is not set.\n");
+	return 0;
+}
+
+#define exit_boot_config()	do {} while (0)
+
+#endif	/* CONFIG_BOOT_CONFIG */
+
+early_param("bootconfig", warn_bootconfig);
+
+bool __init cmdline_has_extra_options(void)
+{
+	return extra_command_line || extra_init_args;
+}
+
+/* Change NUL term back to "=", to make "param" the whole string. */
+static void __init repair_env_string(char *param, char *val)
+{
+	if (val) {
+		/* param=val or param="val"? */
+		if (val == param+strlen(param)+1)
+			val[-1] = '=';
+		else if (val == param+strlen(param)+2) {
+			val[-2] = '=';
+			memmove(val-1, val, strlen(val)+1);
+		} else
+			BUG();
+	}
+}
+
+/* Anything after -- gets handed straight to init. */
+static int __init set_init_arg(char *param, char *val,
+			       const char *unused, void *arg)
+{
+	unsigned int i;
+
+	if (panic_later)
+		return 0;
+
+	repair_env_string(param, val);
+
+	for (i = 0; argv_init[i]; i++) {
+		if (i == MAX_INIT_ARGS) {
+			panic_later = "init";
+			panic_param = param;
+			return 0;
+		}
+	}
+	argv_init[i] = param;
+	return 0;
+}
+
+/*
+ * Unknown boot options get handed to init, unless they look like
+ * unused parameters (modprobe will find them in /proc/cmdline).
+ */
+static int __init unknown_bootoption(char *param, char *val,
+				     const char *unused, void *arg)
+{
+	size_t len = strlen(param);
+	/*
+	 * Well-known bootloader identifiers:
+	 * 1. LILO/Grub pass "BOOT_IMAGE=...";
+	 * 2. kexec/kdump (kexec-tools) pass "kexec".
+	 */
+	const char *bootloader[] = { "BOOT_IMAGE=", "kexec", NULL };
+
+	/* Handle params aliased to sysctls */
+	if (sysctl_is_alias(param))
+		return 0;
+
+	repair_env_string(param, val);
+
+	/* Handle bootloader identifier */
+	for (int i = 0; bootloader[i]; i++) {
+		if (strstarts(param, bootloader[i]))
+			return 0;
+	}
+
+	/* Handle obsolete-style parameters */
+	if (obsolete_checksetup(param))
+		return 0;
+
+	/* Unused module parameter. */
+	if (strnchr(param, len, '.'))
+		return 0;
+
+	if (panic_later)
+		return 0;
+
+	if (val) {
+		/* Environment option */
+		unsigned int i;
+		for (i = 0; envp_init[i]; i++) {
+			if (i == MAX_INIT_ENVS) {
+				panic_later = "env";
+				panic_param = param;
+			}
+			if (!strncmp(param, envp_init[i], len+1))
+				break;
+		}
+		envp_init[i] = param;
+	} else {
+		/* Command line option */
+		unsigned int i;
+		for (i = 0; argv_init[i]; i++) {
+			if (i == MAX_INIT_ARGS) {
+				panic_later = "init";
+				panic_param = param;
+			}
+		}
+		argv_init[i] = param;
+	}
+	return 0;
+}
+
+static int __init init_setup(char *str)
+{
+	unsigned int i;
+
+	execute_command = str;
+	/*
+	 * In case LILO is going to boot us with default command line,
+	 * it prepends "auto" before the whole cmdline which makes
+	 * the shell think it should execute a script with such name.
+	 * So we ignore all arguments entered _before_ init=... [MJ]
+	 */
+	for (i = 1; i < MAX_INIT_ARGS; i++)
+		argv_init[i] = NULL;
+	return 1;
+}
+__setup("init=", init_setup);
+
+static int __init rdinit_setup(char *str)
+{
+	unsigned int i;
+
+	ramdisk_execute_command = str;
+	ramdisk_execute_command_set = true;
+	/* 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 inline void setup_nr_cpu_ids(void) { }
+static inline void smp_prepare_cpus(unsigned int maxcpus) { }
+#endif
+
+/*
+ * We need to store the untouched command line for future reference.
+ * We also need to store the touched command line since the parameter
+ * parsing is performed in place, and we should allow a component to
+ * store reference of name/value for future reference.
+ */
+static void __init setup_command_line(char *command_line)
+{
+	size_t len, xlen = 0, ilen = 0;
+
+	if (extra_command_line)
+		xlen = strlen(extra_command_line);
+	if (extra_init_args) {
+		extra_init_args = strim(extra_init_args); /* remove trailing space */
+		ilen = strlen(extra_init_args) + 4; /* for " -- " */
+	}
+
+	len = xlen + strlen(boot_command_line) + ilen + 1;
+
+	saved_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES);
+
+	len = xlen + strlen(command_line) + 1;
+
+	static_command_line = memblock_alloc_or_panic(len, SMP_CACHE_BYTES);
+
+	if (xlen) {
+		/*
+		 * We have to put extra_command_line before boot command
+		 * lines because there could be dashes (separator of init
+		 * command line) in the command lines.
+		 */
+		strcpy(saved_command_line, extra_command_line);
+		strcpy(static_command_line, extra_command_line);
+	}
+	strcpy(saved_command_line + xlen, boot_command_line);
+	strcpy(static_command_line + xlen, command_line);
+
+	if (ilen) {
+		/*
+		 * Append supplemental init boot args to saved_command_line
+		 * so that user can check what command line options passed
+		 * to init.
+		 * The order should always be
+		 * " -- "[bootconfig init-param][cmdline init-param]
+		 */
+		if (initargs_offs) {
+			len = xlen + initargs_offs;
+			strcpy(saved_command_line + len, extra_init_args);
+			len += ilen - 4;	/* strlen(extra_init_args) */
+			strcpy(saved_command_line + len,
+				boot_command_line + initargs_offs - 1);
+		} else {
+			len = strlen(saved_command_line);
+			strcpy(saved_command_line + len, " -- ");
+			len += 4;
+			strcpy(saved_command_line + len, extra_init_args);
+		}
+	}
+
+	saved_command_line_len = strlen(saved_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 __noreturn rest_init(void)
+{
+	struct kernel_clone_args init_args = {
+		.flags		= (CLONE_VM | CLONE_UNTRACED),
+		.fn		= kernel_init,
+		.fn_arg		= NULL,
+	};
+	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_clone(&init_args);
+	/*
+	 * 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);
+	tsk->flags |= PF_NO_SETAFFINITY;
+	set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
+	rcu_read_unlock();
+
+	numa_default_policy();
+	pid = kernel_thread(kthreadd, NULL, NULL, CLONE_FS | CLONE_FILES);
+	rcu_read_lock();
+	kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
+	rcu_read_unlock();
+
+	/*
+	 * Enable might_sleep() and smp_processor_id() checks.
+	 * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
+	 * kernel_thread() would trigger might_sleep() splats. With
+	 * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
+	 * already, but it's stuck on the kthreadd_done completion.
+	 */
+	system_state = SYSTEM_SCHEDULING;
+
+	complete(&kthreadd_done);
+
+	/*
+	 * The boot idle thread must execute schedule()
+	 * at least once to get things moving:
+	 */
+	schedule_preempt_disabled();
+	/* Call into cpu_idle with preempt disabled */
+	cpu_startup_entry(CPUHP_ONLINE);
+}
+
+/* Check for early params. */
+static int __init do_early_param(char *param, char *val,
+				 const char *unused, void *arg)
+{
+	const struct obs_kernel_param *p;
+
+	for (p = __setup_start; p < __setup_end; p++) {
+		if (p->early && parameq(param, p->str)) {
+			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. */
+	strscpy(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)
+{
+}
+
+void __init __weak smp_prepare_boot_cpu(void)
+{
+}
+
+# if THREAD_SIZE >= PAGE_SIZE
+void __init __weak thread_stack_cache_init(void)
+{
+}
+#endif
+
+void __init __weak poking_init(void) { }
+
+void __init __weak pgtable_cache_init(void) { }
+
+void __init __weak trap_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
+
+#ifdef CONFIG_RANDOMIZE_KSTACK_OFFSET
+DEFINE_STATIC_KEY_MAYBE_RO(CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT,
+			   randomize_kstack_offset);
+DEFINE_PER_CPU(struct rnd_state, kstack_rnd_state);
+
+static int __init random_kstack_init(void)
+{
+	prandom_seed_full_state(&kstack_rnd_state);
+	return 0;
+}
+late_initcall(random_kstack_init);
+
+static int __init early_randomize_kstack_offset(char *buf)
+{
+	int ret;
+	bool bool_result;
+
+	ret = kstrtobool(buf, &bool_result);
+	if (ret)
+		return ret;
+
+	if (bool_result)
+		static_branch_enable(&randomize_kstack_offset);
+	else
+		static_branch_disable(&randomize_kstack_offset);
+	return 0;
+}
+early_param("randomize_kstack_offset", early_randomize_kstack_offset);
+#endif
+
+static void __init print_unknown_bootoptions(void)
+{
+	char *unknown_options;
+	char *end;
+	const char *const *p;
+	size_t len;
+
+	if (panic_later || (!argv_init[1] && !envp_init[2]))
+		return;
+
+	/*
+	 * Determine how many options we have to print out, plus a space
+	 * before each
+	 */
+	len = 1; /* null terminator */
+	for (p = &argv_init[1]; *p; p++) {
+		len++;
+		len += strlen(*p);
+	}
+	for (p = &envp_init[2]; *p; p++) {
+		len++;
+		len += strlen(*p);
+	}
+
+	unknown_options = memblock_alloc(len, SMP_CACHE_BYTES);
+	if (!unknown_options) {
+		pr_err("%s: Failed to allocate %zu bytes\n",
+			__func__, len);
+		return;
+	}
+	end = unknown_options;
+
+	for (p = &argv_init[1]; *p; p++)
+		end += sprintf(end, " %s", *p);
+	for (p = &envp_init[2]; *p; p++)
+		end += sprintf(end, " %s", *p);
+
+	/* Start at unknown_options[1] to skip the initial space */
+	pr_notice("Unknown kernel command line parameters \"%s\", will be passed to user space.\n",
+		&unknown_options[1]);
+	memblock_free(unknown_options, len);
+}
+
+static void __init early_numa_node_init(void)
+{
+#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
+#ifndef cpu_to_node
+	int cpu;
+
+	/* The early_cpu_to_node() should be ready here. */
+	for_each_possible_cpu(cpu)
+		set_cpu_numa_node(cpu, early_cpu_to_node(cpu));
+#endif
+#endif
+}
+
+#define KERNEL_CMDLINE_PREFIX		"Kernel command line: "
+#define KERNEL_CMDLINE_PREFIX_LEN	(sizeof(KERNEL_CMDLINE_PREFIX) - 1)
+#define KERNEL_CMDLINE_CONTINUATION	" \\"
+#define KERNEL_CMDLINE_CONTINUATION_LEN	(sizeof(KERNEL_CMDLINE_CONTINUATION) - 1)
+
+#define MIN_CMDLINE_LOG_WRAP_IDEAL_LEN	(KERNEL_CMDLINE_PREFIX_LEN + \
+					 KERNEL_CMDLINE_CONTINUATION_LEN)
+#define CMDLINE_LOG_WRAP_IDEAL_LEN	(CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN > \
+					 MIN_CMDLINE_LOG_WRAP_IDEAL_LEN ? \
+					 CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN : \
+					 MIN_CMDLINE_LOG_WRAP_IDEAL_LEN)
+
+#define IDEAL_CMDLINE_LEN		(CMDLINE_LOG_WRAP_IDEAL_LEN - KERNEL_CMDLINE_PREFIX_LEN)
+#define IDEAL_CMDLINE_SPLIT_LEN		(IDEAL_CMDLINE_LEN - KERNEL_CMDLINE_CONTINUATION_LEN)
+
+/**
+ * print_kernel_cmdline() - Print the kernel cmdline with wrapping.
+ * @cmdline: The cmdline to print.
+ *
+ * Print the kernel command line, trying to wrap based on the Kconfig knob
+ * CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN.
+ *
+ * Wrapping is based on spaces, ignoring quotes. All lines are prefixed
+ * with "Kernel command line: " and lines that are not the last line have
+ * a " \" suffix added to them. The prefix and suffix count towards the
+ * line length for wrapping purposes. The ideal length will be exceeded
+ * if no appropriate place to wrap is found.
+ *
+ * Example output if CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN is 40:
+ *   Kernel command line: loglevel=7 \
+ *   Kernel command line: init=/sbin/init \
+ *   Kernel command line: root=PARTUUID=8c3efc1a-768b-6642-8d0c-89eb782f19f0/PARTNROFF=1 \
+ *   Kernel command line: rootwait ro \
+ *   Kernel command line: my_quoted_arg="The \
+ *   Kernel command line: quick brown fox \
+ *   Kernel command line: jumps over the \
+ *   Kernel command line: lazy dog."
+ */
+static void __init print_kernel_cmdline(const char *cmdline)
+{
+	size_t len;
+
+	/* Config option of 0 or anything longer than the max disables wrapping */
+	if (CONFIG_CMDLINE_LOG_WRAP_IDEAL_LEN == 0 ||
+	    IDEAL_CMDLINE_LEN >= COMMAND_LINE_SIZE - 1) {
+		pr_notice("%s%s\n", KERNEL_CMDLINE_PREFIX, cmdline);
+		return;
+	}
+
+	len = strlen(cmdline);
+	while (len > IDEAL_CMDLINE_LEN) {
+		const char *first_space;
+		const char *prev_cutoff;
+		const char *cutoff;
+		int to_print;
+		size_t used;
+
+		/* Find the last ' ' that wouldn't make the line too long */
+		prev_cutoff = NULL;
+		cutoff = cmdline;
+		while (true) {
+			cutoff = strchr(cutoff + 1, ' ');
+			if (!cutoff || cutoff - cmdline > IDEAL_CMDLINE_SPLIT_LEN)
+				break;
+			prev_cutoff = cutoff;
+		}
+		if (prev_cutoff)
+			cutoff = prev_cutoff;
+		else if (!cutoff)
+			break;
+
+		/* Find the beginning and end of the string of spaces */
+		first_space = cutoff;
+		while (first_space > cmdline && first_space[-1] == ' ')
+			first_space--;
+		to_print = first_space - cmdline;
+		while (*cutoff == ' ')
+			cutoff++;
+		used = cutoff - cmdline;
+
+		/* If the whole string is used, break and do the final printout */
+		if (len == used)
+			break;
+
+		if (to_print)
+			pr_notice("%s%.*s%s\n", KERNEL_CMDLINE_PREFIX,
+				  to_print, cmdline, KERNEL_CMDLINE_CONTINUATION);
+
+		len -= used;
+		cmdline += used;
+	}
+	if (len)
+		pr_notice("%s%s\n", KERNEL_CMDLINE_PREFIX, cmdline);
+}
+
+asmlinkage __visible __init __no_sanitize_address __noreturn __no_stack_protector
+void start_kernel(void)
+{
+	char *command_line;
+	char *after_dashes;
+
+	set_task_stack_end_magic(&init_task);
+	smp_setup_processor_id();
+	debug_objects_early_init();
+	init_vmlinux_build_id();
+
+	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_core_init_early();
+	/* Static keys and static calls are needed by LSMs */
+	jump_label_init();
+	static_call_init();
+	early_security_init();
+	setup_boot_config();
+	setup_command_line(command_line);
+	setup_nr_cpu_ids();
+	setup_per_cpu_areas();
+	smp_prepare_boot_cpu();	/* arch-specific boot-cpu hooks */
+	early_numa_node_init();
+	boot_cpu_hotplug_init();
+
+	print_kernel_cmdline(saved_command_line);
+	/* parameters may set static keys */
+	parse_early_param();
+	after_dashes = parse_args("Booting kernel",
+				  static_command_line, __start___param,
+				  __stop___param - __start___param,
+				  -1, -1, NULL, &unknown_bootoption);
+	print_unknown_bootoptions();
+	if (!IS_ERR_OR_NULL(after_dashes))
+		parse_args("Setting init args", after_dashes, NULL, 0, -1, -1,
+			   NULL, set_init_arg);
+	if (extra_init_args)
+		parse_args("Setting extra init args", extra_init_args,
+			   NULL, 0, -1, -1, NULL, set_init_arg);
+
+	/* Architectural and non-timekeeping rng init, before allocator init */
+	random_init_early(command_line);
+
+	/*
+	 * These use large bootmem allocations and must precede
+	 * initalization of page allocator
+	 */
+	setup_log_buf(0);
+	vfs_caches_init_early();
+	sort_main_extable();
+	trap_init();
+	mm_core_init();
+	maple_tree_init();
+	poking_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();
+
+	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();
+	kvfree_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();
+	timers_init();
+	srcu_init();
+	hrtimers_init();
+	softirq_init();
+	vdso_setup_data_pages();
+	timekeeping_init();
+	time_init();
+
+	/* This must be after timekeeping is initialized */
+	random_init();
+
+	/* These make use of the fully initialized rng */
+	kfence_init();
+	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();
+
+#ifdef CONFIG_BLK_DEV_INITRD
+	if (initrd_start && !initrd_below_start_ok &&
+	    page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
+		pr_crit("initrd overwritten (0x%08lx < 0x%08lx) - disabling it.\n",
+		    page_to_pfn(virt_to_page((void *)initrd_start)),
+		    min_low_pfn);
+		initrd_start = 0;
+	}
+#endif
+	setup_per_cpu_pageset();
+	numa_policy_init();
+	acpi_early_init();
+	if (late_time_init)
+		late_time_init();
+	sched_clock_init();
+	calibrate_delay();
+
+	arch_cpu_finalize_init();
+
+	pid_idr_init();
+	anon_vma_init();
+	thread_stack_cache_init();
+	cred_init();
+	fork_init();
+	proc_caches_init();
+	uts_ns_init();
+	time_ns_init();
+	key_init();
+	security_init();
+	dbg_late_init();
+	net_ns_init();
+	vfs_caches_init();
+	pagecache_init();
+	signals_init();
+	seq_file_init();
+	proc_root_init();
+	nsfs_init();
+	pidfs_init();
+	cpuset_init();
+	mem_cgroup_init();
+	cgroup_init();
+	taskstats_init_early();
+	delayacct_init();
+
+	acpi_subsystem_init();
+	arch_post_acpi_subsys_init();
+	kcsan_init();
+
+	/* Do the rest non-__init'ed, we're now alive */
+	rest_init();
+
+	/*
+	 * Avoid stack canaries in callers of boot_init_stack_canary for gcc-10
+	 * and older.
+	 */
+#if !__has_attribute(__no_stack_protector__)
+	prevent_tail_call_optimization();
+#endif
+}
+
+/* Call all constructor functions linked into the kernel. */
+static void __init do_ctors(void)
+{
+/*
+ * For UML, the constructors have already been called by the
+ * normal setup code as it's just a normal ELF binary, so we
+ * cannot do it again - but we do need CONFIG_CONSTRUCTORS
+ * even on UML for modules.
+ */
+#if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML)
+	ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
+
+	for (; fn < (ctor_fn_t *) __ctors_end; fn++)
+		(*fn)();
+#endif
+}
+
+#ifdef CONFIG_KALLSYMS
+struct blacklist_entry {
+	struct list_head next;
+	char *buf;
+};
+
+static __initdata_or_module LIST_HEAD(blacklisted_initcalls);
+
+static int __init initcall_blacklist(char *str)
+{
+	char *str_entry;
+	struct blacklist_entry *entry;
+
+	/* str argument is a comma-separated list of functions */
+	do {
+		str_entry = strsep(&str, ",");
+		if (str_entry) {
+			pr_debug("blacklisting initcall %s\n", str_entry);
+			entry = memblock_alloc_or_panic(sizeof(*entry),
+					       SMP_CACHE_BYTES);
+			entry->buf = memblock_alloc_or_panic(strlen(str_entry) + 1,
+						    SMP_CACHE_BYTES);
+			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 = data;
+
+	printk(KERN_DEBUG "calling  %pS @ %i\n", fn, task_pid_nr(current));
+	*calltime = ktime_get();
+}
+
+static __init_or_module void
+trace_initcall_finish_cb(void *data, initcall_t fn, int ret)
+{
+	ktime_t rettime, *calltime = data;
+
+	rettime = ktime_get();
+	printk(KERN_DEBUG "initcall %pS returned %d after %lld usecs\n",
+		 fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime));
+}
+
+static __init_or_module void
+trace_initcall_level_cb(void *data, const char *level)
+{
+	printk(KERN_DEBUG "entering initcall level: %s\n", level);
+}
+
+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);
+	ret |= register_trace_initcall_level(trace_initcall_level_cb, NULL);
+	WARN(ret, "Failed to register initcall tracepoints\n");
+}
+# define do_trace_initcall_start	trace_initcall_start
+# define do_trace_initcall_finish	trace_initcall_finish
+# define do_trace_initcall_level	trace_initcall_level
+#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);
+}
+static inline void do_trace_initcall_level(const char *level)
+{
+	if (!initcall_debug)
+		return;
+	trace_initcall_level_cb(NULL, level);
+}
+#endif /* !TRACEPOINTS_ENABLED */
+
+int __init_or_module do_one_initcall(initcall_t fn)
+{
+	int count = preempt_count();
+	char msgbuf[64];
+	int ret;
+
+	if (initcall_blacklisted(fn))
+		return -EPERM;
+
+	do_trace_initcall_start(fn);
+	ret = fn();
+	do_trace_initcall_finish(fn, ret);
+
+	msgbuf[0] = 0;
+
+	if (preempt_count() != count) {
+		sprintf(msgbuf, "preemption imbalance ");
+		preempt_count_set(count);
+	}
+	if (irqs_disabled()) {
+		strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
+		local_irq_enable();
+	}
+	WARN(msgbuf[0], "initcall %pS returned with %s\n", fn, msgbuf);
+
+	add_latent_entropy();
+	return ret;
+}
+
+
+static initcall_entry_t *initcall_levels[] __initdata = {
+	__initcall0_start,
+	__initcall1_start,
+	__initcall2_start,
+	__initcall3_start,
+	__initcall4_start,
+	__initcall5_start,
+	__initcall6_start,
+	__initcall7_start,
+	__initcall_end,
+};
+
+/* Keep these in sync with initcalls in include/linux/init.h */
+static const char *initcall_level_names[] __initdata = {
+	"pure",
+	"core",
+	"postcore",
+	"arch",
+	"subsys",
+	"fs",
+	"device",
+	"late",
+};
+
+static int __init ignore_unknown_bootoption(char *param, char *val,
+			       const char *unused, void *arg)
+{
+	return 0;
+}
+
+static void __init do_initcall_level(int level, char *command_line)
+{
+	initcall_entry_t *fn;
+
+	parse_args(initcall_level_names[level],
+		   command_line, __start___param,
+		   __stop___param - __start___param,
+		   level, level,
+		   NULL, ignore_unknown_bootoption);
+
+	do_trace_initcall_level(initcall_level_names[level]);
+	for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
+		do_one_initcall(initcall_from_entry(fn));
+}
+
+static void __init do_initcalls(void)
+{
+	int level;
+	size_t len = saved_command_line_len + 1;
+	char *command_line;
+
+	command_line = kzalloc(len, GFP_KERNEL);
+	if (!command_line)
+		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
+
+	for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
+		/* Parser modifies command_line, restore it each time */
+		strcpy(command_line, saved_command_line);
+		do_initcall_level(level, command_line);
+	}
+
+	kfree(command_line);
+}
+
+/*
+ * Ok, the machine is now initialized. None of the devices
+ * have been touched yet, but the CPU subsystem is up and
+ * running, and memory and process management works.
+ *
+ * Now we can finally start doing some real work..
+ */
+static void __init do_basic_setup(void)
+{
+	cpuset_init_smp();
+	ksysfs_init();
+	driver_init();
+	init_irq_proc();
+	do_ctors();
+	do_initcalls();
+}
+
+static void __init do_pre_smp_initcalls(void)
+{
+	initcall_entry_t *fn;
+
+	do_trace_initcall_level("early");
+	for (fn = __initcall_start; fn < __initcall0_start; fn++)
+		do_one_initcall(initcall_from_entry(fn));
+}
+
+static int run_init_process(const char *init_filename)
+{
+	const char *const *p;
+
+	argv_init[0] = init_filename;
+	pr_info("Run %s as init process\n", init_filename);
+	pr_debug("  with arguments:\n");
+	for (p = argv_init; *p; p++)
+		pr_debug("    %s\n", *p);
+	pr_debug("  with environment:\n");
+	for (p = envp_init; *p; p++)
+		pr_debug("    %s\n", *p);
+	return kernel_execve(init_filename, argv_init, envp_init);
+}
+
+static int try_to_run_init_process(const char *init_filename)
+{
+	int ret;
+
+	ret = run_init_process(init_filename);
+
+	if (ret && ret != -ENOENT) {
+		pr_err("Starting init: %s exists but couldn't execute it (error %d)\n",
+		       init_filename, ret);
+	}
+
+	return ret;
+}
+
+static noinline void __init kernel_init_freeable(void);
+
+#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
+bool rodata_enabled __ro_after_init = true;
+
+#ifndef arch_parse_debug_rodata
+static inline bool arch_parse_debug_rodata(char *str) { return false; }
+#endif
+
+static int __init set_debug_rodata(char *str)
+{
+	if (arch_parse_debug_rodata(str))
+		return 0;
+
+	if (str && !strcmp(str, "on"))
+		rodata_enabled = true;
+	else if (str && !strcmp(str, "off"))
+		rodata_enabled = false;
+	else
+		pr_warn("Invalid option string for rodata: '%s'\n", str);
+	return 0;
+}
+early_param("rodata", set_debug_rodata);
+#endif
+
+static void mark_readonly(void)
+{
+	if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) && rodata_enabled) {
+		/*
+		 * load_module() results in W+X mappings, which are cleaned
+		 * up with init_free_wq. 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.
+		 */
+		flush_module_init_free_work();
+		jump_label_init_ro();
+		mark_rodata_ro();
+		debug_checkwx();
+		rodata_test();
+	} else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
+		pr_info("Kernel memory protection disabled.\n");
+	} else if (IS_ENABLED(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)) {
+		pr_warn("Kernel memory protection not selected by kernel config.\n");
+	} else {
+		pr_warn("This architecture does not have kernel memory protection.\n");
+	}
+}
+
+void __weak free_initmem(void)
+{
+	free_initmem_default(POISON_FREE_INITMEM);
+}
+
+static int __ref kernel_init(void *unused)
+{
+	int ret;
+
+	init_userspace_fs();
+
+	/*
+	 * Wait until kthreadd is all set-up.
+	 */
+	wait_for_completion(&kthreadd_done);
+
+	kernel_init_freeable();
+	/* need to finish all async __init code before freeing the memory */
+	async_synchronize_full();
+
+	system_state = SYSTEM_FREEING_INITMEM;
+	kprobe_free_init_mem();
+	ftrace_free_init_mem();
+	kgdb_free_init_mem();
+	exit_boot_config();
+	free_initmem();
+	mark_readonly();
+
+	/*
+	 * Kernel mappings are now finalized - update the userspace page-table
+	 * to finalize PTI.
+	 */
+	pti_finalize();
+
+	system_state = SYSTEM_RUNNING;
+	numa_default_policy();
+
+	rcu_end_inkernel_boot();
+
+	do_sysctl_args();
+
+	if (ramdisk_execute_command) {
+		ret = run_init_process(ramdisk_execute_command);
+		if (!ret)
+			return 0;
+		pr_err("Failed to execute %s (error %d)\n",
+		       ramdisk_execute_command, ret);
+	}
+
+	/*
+	 * We try each of these until one succeeds.
+	 *
+	 * The Bourne shell can be used instead of init if we are
+	 * trying to recover a really broken machine.
+	 */
+	if (execute_command) {
+		ret = run_init_process(execute_command);
+		if (!ret)
+			return 0;
+		panic("Requested init %s failed (error %d).",
+		      execute_command, ret);
+	}
+
+	if (CONFIG_DEFAULT_INIT[0] != '\0') {
+		ret = run_init_process(CONFIG_DEFAULT_INIT);
+		if (ret)
+			pr_err("Default init %s failed (error %d)\n",
+			       CONFIG_DEFAULT_INIT, ret);
+		else
+			return 0;
+	}
+
+	if (!try_to_run_init_process("/sbin/init") ||
+	    !try_to_run_init_process("/etc/init") ||
+	    !try_to_run_init_process("/bin/init") ||
+	    !try_to_run_init_process("/bin/sh"))
+		return 0;
+
+	panic("No working init found.  Try passing init= option to kernel. "
+	      "See Linux Documentation/admin-guide/init.rst for guidance.");
+}
+
+/* Open /dev/console, for stdin/stdout/stderr, this should never fail */
+void __init console_on_rootfs(void)
+{
+	struct file *file = filp_open("/dev/console", O_RDWR, 0);
+
+	if (IS_ERR(file)) {
+		pr_err("Warning: unable to open an initial console.\n");
+		return;
+	}
+	init_dup(file);
+	init_dup(file);
+	init_dup(file);
+	fput(file);
+}
+
+static noinline void __init kernel_init_freeable(void)
+{
+	/* 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]);
+
+	rcu_assign_pointer(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();
+
+	workqueue_init_topology();
+	async_init();
+	padata_init();
+	page_alloc_init_late();
+
+	do_basic_setup();
+
+	kunit_run_all_tests();
+
+	wait_for_initramfs();
+	console_on_rootfs();
+
+	/*
+	 * check if there is an early userspace init.  If yes, let it do all
+	 * the work
+	 */
+	int ramdisk_command_access;
+	ramdisk_command_access = init_eaccess(ramdisk_execute_command);
+	if (ramdisk_command_access != 0) {
+		if (ramdisk_execute_command_set)
+			pr_warn("check access for rdinit=%s failed: %i, ignoring\n",
+				ramdisk_execute_command, ramdisk_command_access);
+		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();
+}