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1706 lines (1453 loc) · 42.3 KB
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// 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.\
10000
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.<
10BC8
/div>
*/
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;