linux/init/main.c

1552 lines
37 KiB
C

// 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/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/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/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/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 <linux/kcsan.h>
#include <linux/init_syscalls.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>
#include <kunit/test.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;
/* 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 bool initargs_found;
#else
# define bootconfig_found false
# define initargs_found false
#endif
static char *execute_command;
static char *ramdisk_execute_command = "/init";
/*
* 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);
#ifdef CONFIG_BLK_DEV_INITRD
static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum)
{
u32 size, csum;
char *data;
u32 *hdr;
int i;
if (!initrd_end)
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 = (u32 *)(data - 8);
size = hdr[0];
csum = hdr[1];
data = ((void *)hdr) - size;
if ((unsigned long)data < initrd_start) {
pr_err("bootconfig size %d is greater than initrd size %ld\n",
size, initrd_end - initrd_start);
return NULL;
}
/* Remove bootconfig from initramfs/initrd */
initrd_end = (unsigned long)data;
if (_size)
*_size = size;
if (_csum)
*_csum = csum;
return data;
}
#else
static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum)
{
return NULL;
}
#endif
#ifdef CONFIG_BOOT_CONFIG
static char xbc_namebuf[XBC_KEYLEN_MAX] __initdata;
#define rest(dst, end) ((end) > (dst) ? (end) - (dst) : 0)
static int __init xbc_snprint_cmdline(char *buf, size_t size,
struct xbc_node *root)
{
struct xbc_node *knode, *vnode;
char *end = buf + size;
const char *val;
int ret;
xbc_node_for_each_key_value(root, knode, val) {
ret = xbc_node_compose_key_after(root, knode,
xbc_namebuf, XBC_KEYLEN_MAX);
if (ret < 0)
return ret;
vnode = xbc_node_get_child(knode);
if (!vnode) {
ret = snprintf(buf, rest(buf, end), "%s ", xbc_namebuf);
if (ret < 0)
return ret;
buf += ret;
continue;
}
xbc_array_for_each_value(vnode, val) {
ret = snprintf(buf, rest(buf, end), "%s=\"%s\" ",
xbc_namebuf, val);
if (ret < 0)
return ret;
buf += ret;
}
}
return buf - (end - size);
}
#undef rest
/* 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");
return NULL;
}
return new_cmdline;
}
static u32 boot_config_checksum(unsigned char *p, u32 size)
{
u32 ret = 0;
while (size--)
ret += *p++;
return ret;
}
static int __init bootconfig_params(char *param, char *val,
const char *unused, void *arg)
{
if (strcmp(param, "bootconfig") == 0) {
bootconfig_found = true;
}
return 0;
}
static void __init setup_boot_config(const char *cmdline)
{
static char tmp_cmdline[COMMAND_LINE_SIZE] __initdata;
const char *msg;
int pos;
u32 size, csum;
char *data, *copy, *err;
int ret;
/* Cut out the bootconfig data even if we have no bootconfig option */
data = get_boot_config_from_initrd(&size, &csum);
strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
err = parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
bootconfig_params);
if (IS_ERR(err) || !bootconfig_found)
return;
/* parse_args() stops at '--' and returns an address */
if (err)
initargs_found = true;
if (!data) {
pr_err("'bootconfig' found on command line, but no bootconfig found\n");
return;
}
if (size >= XBC_DATA_MAX) {
pr_err("bootconfig size %d greater than max size %d\n",
size, XBC_DATA_MAX);
return;
}
if (boot_config_checksum((unsigned char *)data, size) != csum) {
pr_err("bootconfig checksum failed\n");
return;
}
copy = memblock_alloc(size + 1, SMP_CACHE_BYTES);
if (!copy) {
pr_err("Failed to allocate memory for bootconfig\n");
return;
}
memcpy(copy, data, size);
copy[size] = '\0';
ret = xbc_init(copy, &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 {
pr_info("Load bootconfig: %d bytes %d nodes\n", size, ret);
/* keys starting with "kernel." are passed via cmdline */
extra_command_line = xbc_make_cmdline("kernel");
/* Also, "init." keys are init arguments */
extra_init_args = xbc_make_cmdline("init");
}
return;
}
#else
static void __init setup_boot_config(const char *cmdline)
{
/* Remove bootconfig data from initrd */
get_boot_config_from_initrd(NULL, 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;
}
early_param("bootconfig", warn_bootconfig);
#endif
/* 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);
repair_env_string(param, val);
/* 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;
/* 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)
{
size_t len, xlen = 0, ilen = 0;
if (extra_command_line)
xlen = strlen(extra_command_line);
if (extra_init_args)
ilen = strlen(extra_init_args) + 4; /* for " -- " */
len = xlen + strlen(boot_command_line) + 1;
saved_command_line = memblock_alloc(len + ilen, SMP_CACHE_BYTES);
if (!saved_command_line)
panic("%s: Failed to allocate %zu bytes\n", __func__, len + ilen);
static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
if (!static_command_line)
panic("%s: Failed to allocate %zu bytes\n", __func__, len);
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.
*/
len = strlen(saved_command_line);
if (initargs_found) {
saved_command_line[len++] = ' ';
} else {
strcpy(saved_command_line + len, " -- ");
len += 4;
}
strcpy(saved_command_line + len, extra_init_args);
}
}
/*
* 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);
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_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)) ||
(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) { }
void __init __weak poking_init(void) { }
void __init __weak pgtable_cache_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
/* Report memory auto-initialization states for this boot. */
static void __init report_meminit(void)
{
const char *stack;
if (IS_ENABLED(CONFIG_INIT_STACK_ALL_PATTERN))
stack = "all(pattern)";
else if (IS_ENABLED(CONFIG_INIT_STACK_ALL_ZERO))
stack = "all(zero)";
else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL))
stack = "byref_all(zero)";
else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF))
stack = "byref(zero)";
else if (IS_ENABLED(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER))
stack = "__user(zero)";
else
stack = "off";
pr_info("mem auto-init: stack:%s, heap alloc:%s, heap free:%s\n",
stack, want_init_on_alloc(GFP_KERNEL) ? "on" : "off",
want_init_on_free() ? "on" : "off");
if (want_init_on_free())
pr_info("mem auto-init: clearing system memory may take some time...\n");
}
/*
* 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();
init_debug_pagealloc();
report_meminit();
mem_init();
kmem_cache_init();
kmemleak_init();
pgtable_init();
debug_objects_mem_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();
}
void __init __weak arch_call_rest_init(void)
{
rest_init();
}
asmlinkage __visible void __init __no_sanitize_address 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);
early_security_init();
setup_arch(&command_line);
setup_boot_config(command_line);
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", saved_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);
if (extra_init_args)
parse_args("Setting extra init args", extra_init_args,
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();
/*
* 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 rand_initialize()
* - rand_initialize() to get any arch-specific entropy like RDRAND
* - add_latent_entropy() to get any latent entropy
* - adding command line entropy
*/
rand_initialize();
add_latent_entropy();
add_device_randomness(command_line, strlen(command_line));
boot_init_stack_canary();
time_init();
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
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();
poking_init();
check_bugs();
acpi_subsystem_init();
arch_post_acpi_subsys_init();
sfi_init_late();
kcsan_init();
/* Do the rest non-__init'ed, we're now alive */
arch_call_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 = memblock_alloc(sizeof(*entry),
SMP_CACHE_BYTES);
if (!entry)
panic("%s: Failed to allocate %zu bytes\n",
__func__, sizeof(*entry));
entry->buf = memblock_alloc(strlen(str_entry) + 1,
SMP_CACHE_BYTES);
if (!entry->buf)
panic("%s: Failed to allocate %zu bytes\n",
__func__, strlen(str_entry) + 1);
strcpy(entry->buf, str_entry);
list_add(&entry->next, &blacklisted_initcalls);
}
} while (str_entry);
return 0;
}
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 %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 *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 %pS 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 %pS 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 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);
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 = strlen(saved_command_line) + 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();
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));
}
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;
static int __init set_debug_rodata(char *str)
{
return strtobool(str, &rodata_enabled);
}
__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(). 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();
mark_rodata_ro();
rodata_test();
} else
pr_info("Kernel memory protection disabled.\n");
}
#elif defined(CONFIG_ARCH_HAS_STRICT_KERNEL_RWX)
static inline void mark_readonly(void)
{
pr_warn("Kernel memory protection not selected by kernel config.\n");
}
#else
static inline void mark_readonly(void)
{
pr_warn("This architecture does not have kernel memory protection.\n");
}
#endif
void __weak free_initmem(void)
{
free_initmem_default(POISON_FREE_INITMEM);
}
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();
kprobe_free_init_mem();
ftrace_free_init_mem();
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)
{
/*
* 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 = 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();
padata_init();
page_alloc_init_late();
/* Initialize page ext after all struct pages are initialized. */
page_ext_init();
do_basic_setup();
kunit_run_all_tests();
console_on_rootfs();
/*
* check if there is an early userspace init. If yes, let it do all
* the work
*/
if (init_eaccess(ramdisk_execute_command) != 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();
}