main.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2002 Richard Henderson
 * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
 * Copyright (C) 2023 Luis Chamberlain <mcgrof@kernel.org>
 */

#define INCLUDE_VERMAGIC

#include <linux/export.h>
#include <linux/extable.h>
#include <linux/moduleloader.h>
#include <linux/module_signature.h>
#include <linux/trace_events.h>
#include <linux/init.h>
#include <linux/kallsyms.h>
#include <linux/buildid.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/kernel_read_file.h>
#include <linux/kstrtox.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/elf.h>
#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/fcntl.h>
#include <linux/rcupdate.h>
#include <linux/capability.h>
#include <linux/cpu.h>
#include <linux/moduleparam.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/vermagic.h>
#include <linux/notifier.h>
#include <linux/sched.h>
#include <linux/device.h>
#include <linux/string.h>
#include <linux/mutex.h>
#include <linux/rculist.h>
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
#include <linux/set_memory.h>
#include <asm/mmu_context.h>
#include <linux/license.h>
#include <asm/sections.h>
#include <linux/tracepoint.h>
#include <linux/ftrace.h>
#include <linux/livepatch.h>
#include <linux/async.h>
#include <linux/percpu.h>
#include <linux/kmemleak.h>
#include <linux/jump_label.h>
#include <linux/pfn.h>
#include <linux/bsearch.h>
#include <linux/dynamic_debug.h>
#include <linux/audit.h>
#include <linux/cfi.h>
#include <linux/codetag.h>
#include <linux/debugfs.h>
#include <linux/execmem.h>
#include <uapi/linux/module.h>
#include "internal.h"

#define CREATE_TRACE_POINTS
#include <trace/events/module.h>

/*
 * Mutex protects:
 * 1) List of modules (also safely readable with preempt_disable),
 * 2) module_use links,
 * 3) mod_tree.addr_min/mod_tree.addr_max.
 * (delete and add uses RCU list operations).
 */
DEFINE_MUTEX(module_mutex);
LIST_HEAD(modules);

/* Work queue for freeing init sections in success case */
static void do_free_init(struct work_struct *w);
static DECLARE_WORK(init_free_wq, do_free_init);
static LLIST_HEAD(init_free_list);

struct mod_tree_root mod_tree __cacheline_aligned = {
	.addr_min = -1UL,
};

struct symsearch {
	const struct kernel_symbol *start, *stop;
	const s32 *crcs;
	enum mod_license license;
};

/*
 * Bounds of module memory, for speeding up __module_address.
 * Protected by module_mutex.
 */
static void __mod_update_bounds(enum mod_mem_type type __maybe_unused, void *base,
				unsigned int size, struct mod_tree_root *tree)
{
	unsigned long min = (unsigned long)base;
	unsigned long max = min + size;

#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
	if (mod_mem_type_is_core_data(type)) {
		if (min < tree->data_addr_min)
			tree->data_addr_min = min;
		if (max > tree->data_addr_max)
			tree->data_addr_max = max;
		return;
	}
#endif
	if (min < tree->addr_min)
		tree->addr_min = min;
	if (max > tree->addr_max)
		tree->addr_max = max;
}

static void mod_update_bounds(struct module *mod)
{
	for_each_mod_mem_type(type) {
		struct module_memory *mod_mem = &mod->mem[type];

		if (mod_mem->size)
			__mod_update_bounds(type, mod_mem->base, mod_mem->size, &mod_tree);
	}
}

/* Block module loading/unloading? */
int modules_disabled;
core_param(nomodule, modules_disabled, bint, 0);

/* Waiting for a module to finish initializing? */
static DECLARE_WAIT_QUEUE_HEAD(module_wq);

static BLOCKING_NOTIFIER_HEAD(module_notify_list);

int register_module_notifier(struct notifier_block *nb)
{
	return blocking_notifier_chain_register(&module_notify_list, nb);
}
EXPORT_SYMBOL(register_module_notifier);

int unregister_module_notifier(struct notifier_block *nb)
{
	return blocking_notifier_chain_unregister(&module_notify_list, nb);
}
EXPORT_SYMBOL(unregister_module_notifier);

/*
 * We require a truly strong try_module_get(): 0 means success.
 * Otherwise an error is returned due to ongoing or failed
 * initialization etc.
 */
static inline int strong_try_module_get(struct module *mod)
{
	BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
	if (mod && mod->state == MODULE_STATE_COMING)
		return -EBUSY;
	if (try_module_get(mod))
		return 0;
	else
		return -ENOENT;
}

static inline void add_taint_module(struct module *mod, unsigned flag,
				    enum lockdep_ok lockdep_ok)
{
	add_taint(flag, lockdep_ok);
	set_bit(flag, &mod->taints);
}

/*
 * A thread that wants to hold a reference to a module only while it
 * is running can call this to safely exit.
 */
void __noreturn __module_put_and_kthread_exit(struct module *mod, long code)
{
	module_put(mod);
	kthread_exit(code);
}
EXPORT_SYMBOL(__module_put_and_kthread_exit);

/* Find a module section: 0 means not found. */
static unsigned int find_sec(const struct load_info *info, const char *name)
{
	unsigned int i;

	for (i = 1; i < info->hdr->e_shnum; i++) {
		Elf_Shdr *shdr = &info->sechdrs[i];
		/* Alloc bit cleared means "ignore it." */
		if ((shdr->sh_flags & SHF_ALLOC)
		    && strcmp(info->secstrings + shdr->sh_name, name) == 0)
			return i;
	}
	return 0;
}

/* Find a module section, or NULL. */
static void *section_addr(const struct load_info *info, const char *name)
{
	/* Section 0 has sh_addr 0. */
	return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
}

/* Find a module section, or NULL.  Fill in number of "objects" in section. */
static void *section_objs(const struct load_info *info,
			  const char *name,
			  size_t object_size,
			  unsigned int *num)
{
	unsigned int sec = find_sec(info, name);

	/* Section 0 has sh_addr 0 and sh_size 0. */
	*num = info->sechdrs[sec].sh_size / object_size;
	return (void *)info->sechdrs[sec].sh_addr;
}

/* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */
static unsigned int find_any_sec(const struct load_info *info, const char *name)
{
	unsigned int i;

	for (i = 1; i < info->hdr->e_shnum; i++) {
		Elf_Shdr *shdr = &info->sechdrs[i];
		if (strcmp(info->secstrings + shdr->sh_name, name) == 0)
			return i;
	}
	return 0;
}

/*
 * Find a module section, or NULL. Fill in number of "objects" in section.
 * Ignores SHF_ALLOC flag.
 */
static __maybe_unused void *any_section_objs(const struct load_info *info,
					     const char *name,
					     size_t object_size,
					     unsigned int *num)
{
	unsigned int sec = find_any_sec(info, name);

	/* Section 0 has sh_addr 0 and sh_size 0. */
	*num = info->sechdrs[sec].sh_size / object_size;
	return (void *)info->sechdrs[sec].sh_addr;
}

#ifndef CONFIG_MODVERSIONS
#define symversion(base, idx) NULL
#else
#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
#endif

static const char *kernel_symbol_name(const struct kernel_symbol *sym)
{
#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
	return offset_to_ptr(&sym->name_offset);
#else
	return sym->name;
#endif
}

static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
{
#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
	if (!sym->namespace_offset)
		return NULL;
	return offset_to_ptr(&sym->namespace_offset);
#else
	return sym->namespace;
#endif
}

int cmp_name(const void *name, const void *sym)
{
	return strcmp(name, kernel_symbol_name(sym));
}

static bool find_exported_symbol_in_section(const struct symsearch *syms,
					    struct module *owner,
					    struct find_symbol_arg *fsa)
{
	struct kernel_symbol *sym;

	if (!fsa->gplok && syms->license == GPL_ONLY)
		return false;

	sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
			sizeof(struct kernel_symbol), cmp_name);
	if (!sym)
		return false;

	fsa->owner = owner;
	fsa->crc = symversion(syms->crcs, sym - syms->start);
	fsa->sym = sym;
	fsa->license = syms->license;

	return true;
}

/*
 * Find an exported symbol and return it, along with, (optional) crc and
 * (optional) module which owns it.  Needs preempt disabled or module_mutex.
 */
bool find_symbol(struct find_symbol_arg *fsa)
{
	static const struct symsearch arr[] = {
		{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
		  NOT_GPL_ONLY },
		{ __start___ksymtab_gpl, __stop___ksymtab_gpl,
		  __start___kcrctab_gpl,
		  GPL_ONLY },
	};
	struct module *mod;
	unsigned int i;

	module_assert_mutex_or_preempt();

	for (i = 0; i < ARRAY_SIZE(arr); i++)
		if (find_exported_symbol_in_section(&arr[i], NULL, fsa))
			return true;

	list_for_each_entry_rcu(mod, &modules, list,
				lockdep_is_held(&module_mutex)) {
		struct symsearch arr[] = {
			{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
			  NOT_GPL_ONLY },
			{ mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
			  mod->gpl_crcs,
			  GPL_ONLY },
		};

		if (mod->state == MODULE_STATE_UNFORMED)
			continue;

		for (i = 0; i < ARRAY_SIZE(arr); i++)
			if (find_exported_symbol_in_section(&arr[i], mod, fsa))
				return true;
	}

	pr_debug("Failed to find symbol %s\n", fsa->name);
	return false;
}

/*
 * Search for module by name: must hold module_mutex (or preempt disabled
 * for read-only access).
 */
struct module *find_module_all(const char *name, size_t len,
			       bool even_unformed)
{
	struct module *mod;

	module_assert_mutex_or_preempt();

	list_for_each_entry_rcu(mod, &modules, list,
				lockdep_is_held(&module_mutex)) {
		if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
			continue;
		if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
			return mod;
	}
	return NULL;
}

struct module *find_module(const char *name)
{
	return find_module_all(name, strlen(name), false);
}

#ifdef CONFIG_SMP

static inline void __percpu *mod_percpu(struct module *mod)
{
	return mod->percpu;
}

static int percpu_modalloc(struct module *mod, struct load_info *info)
{
	Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
	unsigned long align = pcpusec->sh_addralign;

	if (!pcpusec->sh_size)
		return 0;

	if (align > PAGE_SIZE) {
		pr_warn("%s: per-cpu alignment %li > %li\n",
			mod->name, align, PAGE_SIZE);
		align = PAGE_SIZE;
	}

	mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
	if (!mod->percpu) {
		pr_warn("%s: Could not allocate %lu bytes percpu data\n",
			mod->name, (unsigned long)pcpusec->sh_size);
		return -ENOMEM;
	}
	mod->percpu_size = pcpusec->sh_size;
	return 0;
}

static void percpu_modfree(struct module *mod)
{
	free_percpu(mod->percpu);
}

static unsigned int find_pcpusec(struct load_info *info)
{
	return find_sec(info, ".data..percpu");
}

static void percpu_modcopy(struct module *mod,
			   const void *from, unsigned long size)
{
	int cpu;

	for_each_possible_cpu(cpu)
		memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
}

bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
{
	struct module *mod;
	unsigned int cpu;

	preempt_disable();

	list_for_each_entry_rcu(mod, &modules, list) {
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
		if (!mod->percpu_size)
			continue;
		for_each_possible_cpu(cpu) {
			void *start = per_cpu_ptr(mod->percpu, cpu);
			void *va = (void *)addr;

			if (va >= start && va < start + mod->percpu_size) {
				if (can_addr) {
					*can_addr = (unsigned long) (va - start);
					*can_addr += (unsigned long)
						per_cpu_ptr(mod->percpu,
							    get_boot_cpu_id());
				}
				preempt_enable();
				return true;
			}
		}
	}

	preempt_enable();
	return false;
}

/**
 * is_module_percpu_address() - test whether address is from module static percpu
 * @addr: address to test
 *
 * Test whether @addr belongs to module static percpu area.
 *
 * Return: %true if @addr is from module static percpu area
 */
bool is_module_percpu_address(unsigned long addr)
{
	return __is_module_percpu_address(addr, NULL);
}

#else /* ... !CONFIG_SMP */

static inline void __percpu *mod_percpu(struct module *mod)
{
	return NULL;
}
static int percpu_modalloc(struct module *mod, struct load_info *info)
{
	/* UP modules shouldn't have this section: ENOMEM isn't quite right */
	if (info->sechdrs[info->index.pcpu].sh_size != 0)
		return -ENOMEM;
	return 0;
}
static inline void percpu_modfree(struct module *mod)
{
}
static unsigned int find_pcpusec(struct load_info *info)
{
	return 0;
}
static inline void percpu_modcopy(struct module *mod,
				  const void *from, unsigned long size)
{
	/* pcpusec should be 0, and size of that section should be 0. */
	BUG_ON(size != 0);
}
bool is_module_percpu_address(unsigned long addr)
{
	return false;
}

bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
{
	return false;
}

#endif /* CONFIG_SMP */

#define MODINFO_ATTR(field)	\
static void setup_modinfo_##field(struct module *mod, const char *s)  \
{                                                                     \
	mod->field = kstrdup(s, GFP_KERNEL);                          \
}                                                                     \
static ssize_t show_modinfo_##field(struct module_attribute *mattr,   \
			struct module_kobject *mk, char *buffer)      \
{                                                                     \
	return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field);  \
}                                                                     \
static int modinfo_##field##_exists(struct module *mod)               \
{                                                                     \
	return mod->field != NULL;                                    \
}                                                                     \
static void free_modinfo_##field(struct module *mod)                  \
{                                                                     \
	kfree(mod->field);                                            \
	mod->field = NULL;                                            \
}                                                                     \
static struct module_attribute modinfo_##field = {                    \
	.attr = { .name = __stringify(field), .mode = 0444 },         \
	.show = show_modinfo_##field,                                 \
	.setup = setup_modinfo_##field,                               \
	.test = modinfo_##field##_exists,                             \
	.free = free_modinfo_##field,                                 \
};

MODINFO_ATTR(version);
MODINFO_ATTR(srcversion);

static struct {
	char name[MODULE_NAME_LEN + 1];
	char taints[MODULE_FLAGS_BUF_SIZE];
} last_unloaded_module;

#ifdef CONFIG_MODULE_UNLOAD

EXPORT_TRACEPOINT_SYMBOL(module_get);

/* MODULE_REF_BASE is the base reference count by kmodule loader. */
#define MODULE_REF_BASE	1

/* Init the unload section of the module. */
static int module_unload_init(struct module *mod)
{
	/*
	 * Initialize reference counter to MODULE_REF_BASE.
	 * refcnt == 0 means module is going.
	 */
	atomic_set(&mod->refcnt, MODULE_REF_BASE);

	INIT_LIST_HEAD(&mod->source_list);
	INIT_LIST_HEAD(&mod->target_list);

	/* Hold reference count during initialization. */
	atomic_inc(&mod->refcnt);

	return 0;
}

/* Does a already use b? */
static int already_uses(struct module *a, struct module *b)
{
	struct module_use *use;

	list_for_each_entry(use, &b->source_list, source_list) {
		if (use->source == a)
			return 1;
	}
	pr_debug("%s does not use %s!\n", a->name, b->name);
	return 0;
}

/*
 * Module a uses b
 *  - we add 'a' as a "source", 'b' as a "target" of module use
 *  - the module_use is added to the list of 'b' sources (so
 *    'b' can walk the list to see who sourced them), and of 'a'
 *    targets (so 'a' can see what modules it targets).
 */
static int add_module_usage(struct module *a, struct module *b)
{
	struct module_use *use;

	pr_debug("Allocating new usage for %s.\n", a->name);
	use = kmalloc(sizeof(*use), GFP_ATOMIC);
	if (!use)
		return -ENOMEM;

	use->source = a;
	use->target = b;
	list_add(&use->source_list, &b->source_list);
	list_add(&use->target_list, &a->target_list);
	return 0;
}

/* Module a uses b: caller needs module_mutex() */
static int ref_module(struct module *a, struct module *b)
{
	int err;

	if (b == NULL || already_uses(a, b))
		return 0;

	/* If module isn't available, we fail. */
	err = strong_try_module_get(b);
	if (err)
		return err;

	err = add_module_usage(a, b);
	if (err) {
		module_put(b);
		return err;
	}
	return 0;
}

/* Clear the unload stuff of the module. */
static void module_unload_free(struct module *mod)
{
	struct module_use *use, *tmp;

	mutex_lock(&module_mutex);
	list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
		struct module *i = use->target;
		pr_debug("%s unusing %s\n", mod->name, i->name);
		module_put(i);
		list_del(&use->source_list);
		list_del(&use->target_list);
		kfree(use);
	}
	mutex_unlock(&module_mutex);
}

#ifdef CONFIG_MODULE_FORCE_UNLOAD
static inline int try_force_unload(unsigned int flags)
{
	int ret = (flags & O_TRUNC);
	if (ret)
		add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
	return ret;
}
#else
static inline int try_force_unload(unsigned int flags)
{
	return 0;
}
#endif /* CONFIG_MODULE_FORCE_UNLOAD */

/* Try to release refcount of module, 0 means success. */
static int try_release_module_ref(struct module *mod)
{
	int ret;

	/* Try to decrement refcnt which we set at loading */
	ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
	BUG_ON(ret < 0);
	if (ret)
		/* Someone can put this right now, recover with checking */
		ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);

	return ret;
}

static int try_stop_module(struct module *mod, int flags, int *forced)
{
	/* If it's not unused, quit unless we're forcing. */
	if (try_release_module_ref(mod) != 0) {
		*forced = try_force_unload(flags);
		if (!(*forced))
			return -EWOULDBLOCK;
	}

	/* Mark it as dying. */
	mod->state = MODULE_STATE_GOING;

	return 0;
}

/**
 * module_refcount() - return the refcount or -1 if unloading
 * @mod:	the module we're checking
 *
 * Return:
 *	-1 if the module is in the process of unloading
 *	otherwise the number of references in the kernel to the module
 */
int module_refcount(struct module *mod)
{
	return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
}
EXPORT_SYMBOL(module_refcount);

/* This exists whether we can unload or not */
static void free_module(struct module *mod);

SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
		unsigned int, flags)
{
	struct module *mod;
	char name[MODULE_NAME_LEN];
	char buf[MODULE_FLAGS_BUF_SIZE];
	int ret, forced = 0;

	if (!capable(CAP_SYS_MODULE) || modules_disabled)
		return -EPERM;

	if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
		return -EFAULT;
	name[MODULE_NAME_LEN-1] = '\0';

	audit_log_kern_module(name);

	if (mutex_lock_interruptible(&module_mutex) != 0)
		return -EINTR;

	mod = find_module(name);
	if (!mod) {
		ret = -ENOENT;
		goto out;
	}

	if (!list_empty(&mod->source_list)) {
		/* Other modules depend on us: get rid of them first. */
		ret = -EWOULDBLOCK;
		goto out;
	}

	/* Doing init or already dying? */
	if (mod->state != MODULE_STATE_LIVE) {
		/* FIXME: if (force), slam module count damn the torpedoes */
		pr_debug("%s already dying\n", mod->name);
		ret = -EBUSY;
		goto out;
	}

	/* If it has an init func, it must have an exit func to unload */
	if (mod->init && !mod->exit) {
		forced = try_force_unload(flags);
		if (!forced) {
			/* This module can't be removed */
			ret = -EBUSY;
			goto out;
		}
	}

	ret = try_stop_module(mod, flags, &forced);
	if (ret != 0)
		goto out;

	mutex_unlock(&module_mutex);
	/* Final destruction now no one is using it. */
	if (mod->exit != NULL)
		mod->exit();
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
	klp_module_going(mod);
	ftrace_release_mod(mod);

	async_synchronize_full();

	/* Store the name and taints of the last unloaded module for diagnostic purposes */
	strscpy(last_unloaded_module.name, mod->name, sizeof(last_unloaded_module.name));
	strscpy(last_unloaded_module.taints, module_flags(mod, buf, false), sizeof(last_unloaded_module.taints));

	free_module(mod);
	/* someone could wait for the module in add_unformed_module() */
	wake_up_all(&module_wq);
	return 0;
out:
	mutex_unlock(&module_mutex);
	return ret;
}

void __symbol_put(const char *symbol)
{
	struct find_symbol_arg fsa = {
		.name	= symbol,
		.gplok	= true,
	};

	preempt_disable();
	BUG_ON(!find_symbol(&fsa));
	module_put(fsa.owner);
	preempt_enable();
}
EXPORT_SYMBOL(__symbol_put);

/* Note this assumes addr is a function, which it currently always is. */
void symbol_put_addr(void *addr)
{
	struct module *modaddr;
	unsigned long a = (unsigned long)dereference_function_descriptor(addr);

	if (core_kernel_text(a))
		return;

	/*
	 * Even though we hold a reference on the module; we still need to
	 * disable preemption in order to safely traverse the data structure.
	 */
	preempt_disable();
	modaddr = __module_text_address(a);
	BUG_ON(!modaddr);
	module_put(modaddr);
	preempt_enable();
}
EXPORT_SYMBOL_GPL(symbol_put_addr);

static ssize_t show_refcnt(struct module_attribute *mattr,
			   struct module_kobject *mk, char *buffer)
{
	return sprintf(buffer, "%i\n", module_refcount(mk->mod));
}

static struct module_attribute modinfo_refcnt =
	__ATTR(refcnt, 0444, show_refcnt, NULL);

void __module_get(struct module *module)
{
	if (module) {
		atomic_inc(&module->refcnt);
		trace_module_get(module, _RET_IP_);
	}
}
EXPORT_SYMBOL(__module_get);

bool try_module_get(struct module *module)
{
	bool ret = true;

	if (module) {
		/* Note: here, we can fail to get a reference */
		if (likely(module_is_live(module) &&
			   atomic_inc_not_zero(&module->refcnt) != 0))
			trace_module_get(module, _RET_IP_);
		else
			ret = false;
	}
	return ret;
}
EXPORT_SYMBOL(try_module_get);

void module_put(struct module *module)
{
	int ret;

	if (module) {
		ret = atomic_dec_if_positive(&module->refcnt);
		WARN_ON(ret < 0);	/* Failed to put refcount */
		trace_module_put(module, _RET_IP_);
	}
}
EXPORT_SYMBOL(module_put);

#else /* !CONFIG_MODULE_UNLOAD */
static inline void module_unload_free(struct module *mod)
{
}

static int ref_module(struct module *a, struct module *b)
{
	return strong_try_module_get(b);
}

static inline int module_unload_init(struct module *mod)
{
	return 0;
}
#endif /* CONFIG_MODULE_UNLOAD */

size_t module_flags_taint(unsigned long taints, char *buf)
{
	size_t l = 0;
	int i;

	for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
		if (taint_flags[i].module && test_bit(i, &taints))
			buf[l++] = taint_flags[i].c_true;
	}

	return l;
}

static ssize_t show_initstate(struct module_attribute *mattr,
			      struct module_kobject *mk, char *buffer)
{
	const char *state = "unknown";

	switch (mk->mod->state) {
	case MODULE_STATE_LIVE:
		state = "live";
		break;
	case MODULE_STATE_COMING:
		state = "coming";
		break;
	case MODULE_STATE_GOING:
		state = "going";
		break;
	default:
		BUG();
	}
	return sprintf(buffer, "%s\n", state);
}

static struct module_attribute modinfo_initstate =
	__ATTR(initstate, 0444, show_initstate, NULL);

static ssize_t store_uevent(struct module_attribute *mattr,
			    struct module_kobject *mk,
			    const char *buffer, size_t count)
{
	int rc;

	rc = kobject_synth_uevent(&mk->kobj, buffer, count);
	return rc ? rc : count;
}

struct module_attribute module_uevent =
	__ATTR(uevent, 0200, NULL, store_uevent);

static ssize_t show_coresize(struct module_attribute *mattr,
			     struct module_kobject *mk, char *buffer)
{
	unsigned int size = mk->mod->mem[MOD_TEXT].size;

	if (!IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC)) {
		for_class_mod_mem_type(type, core_data)
			size += mk->mod->mem[type].size;
	}
	return sprintf(buffer, "%u\n", size);
}

static struct module_attribute modinfo_coresize =
	__ATTR(coresize, 0444, show_coresize, NULL);

#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
static ssize_t show_datasize(struct module_attribute *mattr,
			     struct module_kobject *mk, char *buffer)
{
	unsigned int size = 0;

	for_class_mod_mem_type(type, core_data)
		size += mk->mod->mem[type].size;
	return sprintf(buffer, "%u\n", size);
}

static struct module_attribute modinfo_datasize =
	__ATTR(datasize, 0444, show_datasize, NULL);
#endif

static ssize_t show_initsize(struct module_attribute *mattr,
			     struct module_kobject *mk, char *buffer)
{
	unsigned int size = 0;

	for_class_mod_mem_type(type, init)
		size += mk->mod->mem[type].size;
	return sprintf(buffer, "%u\n", size);
}

static struct module_attribute modinfo_initsize =
	__ATTR(initsize, 0444, show_initsize, NULL);

static ssize_t show_taint(struct module_attribute *mattr,
			  struct module_kobject *mk, char *buffer)
{
	size_t l;

	l = module_flags_taint(mk->mod->taints, buffer);
	buffer[l++] = '\n';
	return l;
}

static struct module_attribute modinfo_taint =
	__ATTR(taint, 0444, show_taint, NULL);

struct module_attribute *modinfo_attrs[] = {
	&module_uevent,
	&modinfo_version,
	&modinfo_srcversion,
	&modinfo_initstate,
	&modinfo_coresize,
#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
	&modinfo_datasize,
#endif
	&modinfo_initsize,
	&modinfo_taint,
#ifdef CONFIG_MODULE_UNLOAD
	&modinfo_refcnt,
#endif
	NULL,
};

size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs);

static const char vermagic[] = VERMAGIC_STRING;