module.c 102.3 KB
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/*
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   Copyright (C) 2002 Richard Henderson
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   Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
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    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
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#include <linux/export.h>
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#include <linux/moduleloader.h>
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#include <linux/trace_events.h>
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#include <linux/init.h>
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#include <linux/kallsyms.h>
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#include <linux/file.h>
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#include <linux/fs.h>
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#include <linux/sysfs.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/elf.h>
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#include <linux/proc_fs.h>
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#include <linux/security.h>
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#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/fcntl.h>
#include <linux/rcupdate.h>
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#include <linux/capability.h>
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#include <linux/cpu.h>
#include <linux/moduleparam.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/vermagic.h>
#include <linux/notifier.h>
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#include <linux/sched.h>
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#include <linux/device.h>
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#include <linux/string.h>
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#include <linux/mutex.h>
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#include <linux/rculist.h>
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#include <asm/uaccess.h>
#include <asm/cacheflush.h>
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#include <asm/mmu_context.h>
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#include <linux/license.h>
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#include <asm/sections.h>
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#include <linux/tracepoint.h>
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#include <linux/ftrace.h>
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#include <linux/async.h>
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#include <linux/percpu.h>
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#include <linux/kmemleak.h>
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#include <linux/jump_label.h>
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#include <linux/pfn.h>
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#include <linux/bsearch.h>
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#include <uapi/linux/module.h>
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#include "module-internal.h"
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#define CREATE_TRACE_POINTS
#include <trace/events/module.h>

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#ifndef ARCH_SHF_SMALL
#define ARCH_SHF_SMALL 0
#endif

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/*
 * Modules' sections will be aligned on page boundaries
 * to ensure complete separation of code and data, but
 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
 */
#ifdef CONFIG_DEBUG_SET_MODULE_RONX
# define debug_align(X) ALIGN(X, PAGE_SIZE)
#else
# define debug_align(X) (X)
#endif

/*
 * Given BASE and SIZE this macro calculates the number of pages the
 * memory regions occupies
 */
#define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ?		\
		(PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) -	\
			 PFN_DOWN((unsigned long)BASE) + 1)	\
		: (0UL))

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/* If this is set, the section belongs in the init part of the module */
#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))

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/*
 * Mutex protects:
 * 1) List of modules (also safely readable with preempt_disable),
 * 2) module_use links,
 * 3) module_addr_min/module_addr_max.
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 * (delete and add uses RCU list operations). */
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DEFINE_MUTEX(module_mutex);
EXPORT_SYMBOL_GPL(module_mutex);
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static LIST_HEAD(modules);
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#ifdef CONFIG_MODULES_TREE_LOOKUP
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/*
 * Use a latched RB-tree for __module_address(); this allows us to use
 * RCU-sched lookups of the address from any context.
 *
 * Because modules have two address ranges: init and core, we need two
 * latch_tree_nodes entries. Therefore we need the back-pointer from
 * mod_tree_node.
 *
 * Because init ranges are short lived we mark them unlikely and have placed
 * them outside the critical cacheline in struct module.
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 *
 * This is conditional on PERF_EVENTS || TRACING because those can really hit
 * __module_address() hard by doing a lot of stack unwinding; potentially from
 * NMI context.
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 */

static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
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{
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	struct mod_tree_node *mtn = container_of(n, struct mod_tree_node, node);
	struct module *mod = mtn->mod;
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	if (unlikely(mtn == &mod->mtn_init))
		return (unsigned long)mod->module_init;
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	return (unsigned long)mod->module_core;
}

static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
{
	struct mod_tree_node *mtn = container_of(n, struct mod_tree_node, node);
	struct module *mod = mtn->mod;
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	if (unlikely(mtn == &mod->mtn_init))
		return (unsigned long)mod->init_size;

	return (unsigned long)mod->core_size;
}

static __always_inline bool
mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
{
	return __mod_tree_val(a) < __mod_tree_val(b);
}

static __always_inline int
mod_tree_comp(void *key, struct latch_tree_node *n)
{
	unsigned long val = (unsigned long)key;
	unsigned long start, end;

	start = __mod_tree_val(n);
	if (val < start)
		return -1;

	end = start + __mod_tree_size(n);
	if (val >= end)
		return 1;
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	return 0;
}

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static const struct latch_tree_ops mod_tree_ops = {
	.less = mod_tree_less,
	.comp = mod_tree_comp,
};

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static struct mod_tree_root {
	struct latch_tree_root root;
	unsigned long addr_min;
	unsigned long addr_max;
} mod_tree __cacheline_aligned = {
	.addr_min = -1UL,
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};

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#define module_addr_min mod_tree.addr_min
#define module_addr_max mod_tree.addr_max

static noinline void __mod_tree_insert(struct mod_tree_node *node)
{
	latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
}

static void __mod_tree_remove(struct mod_tree_node *node)
{
	latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
}
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/*
 * These modifications: insert, remove_init and remove; are serialized by the
 * module_mutex.
 */
static void mod_tree_insert(struct module *mod)
{
	mod->mtn_core.mod = mod;
	mod->mtn_init.mod = mod;

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	__mod_tree_insert(&mod->mtn_core);
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	if (mod->init_size)
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		__mod_tree_insert(&mod->mtn_init);
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}

static void mod_tree_remove_init(struct module *mod)
{
	if (mod->init_size)
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		__mod_tree_remove(&mod->mtn_init);
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}

static void mod_tree_remove(struct module *mod)
{
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	__mod_tree_remove(&mod->mtn_core);
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	mod_tree_remove_init(mod);
}

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static struct module *mod_find(unsigned long addr)
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{
	struct latch_tree_node *ltn;

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	ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
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	if (!ltn)
		return NULL;

	return container_of(ltn, struct mod_tree_node, node)->mod;
}

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#else /* MODULES_TREE_LOOKUP */

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static unsigned long module_addr_min = -1UL, module_addr_max = 0;

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static void mod_tree_insert(struct module *mod) { }
static void mod_tree_remove_init(struct module *mod) { }
static void mod_tree_remove(struct module *mod) { }

static struct module *mod_find(unsigned long addr)
{
	struct module *mod;

	list_for_each_entry_rcu(mod, &modules, list) {
		if (within_module(addr, mod))
			return mod;
	}

	return NULL;
}

#endif /* MODULES_TREE_LOOKUP */

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/*
 * Bounds of module text, for speeding up __module_address.
 * Protected by module_mutex.
 */
static void __mod_update_bounds(void *base, unsigned int size)
{
	unsigned long min = (unsigned long)base;
	unsigned long max = min + size;

	if (min < module_addr_min)
		module_addr_min = min;
	if (max > module_addr_max)
		module_addr_max = max;
}

static void mod_update_bounds(struct module *mod)
{
	__mod_update_bounds(mod->module_core, mod->core_size);
	if (mod->init_size)
		__mod_update_bounds(mod->module_init, mod->init_size);
}

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#ifdef CONFIG_KGDB_KDB
struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
#endif /* CONFIG_KGDB_KDB */

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static void module_assert_mutex(void)
{
	lockdep_assert_held(&module_mutex);
}

static void module_assert_mutex_or_preempt(void)
{
#ifdef CONFIG_LOCKDEP
	if (unlikely(!debug_locks))
		return;

	WARN_ON(!rcu_read_lock_sched_held() &&
		!lockdep_is_held(&module_mutex));
#endif
}

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static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
#ifndef CONFIG_MODULE_SIG_FORCE
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module_param(sig_enforce, bool_enable_only, 0644);
#endif /* !CONFIG_MODULE_SIG_FORCE */
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/* Block module loading/unloading? */
int modules_disabled = 0;
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core_param(nomodule, modules_disabled, bint, 0);
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/* Waiting for a module to finish initializing? */
static DECLARE_WAIT_QUEUE_HEAD(module_wq);

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

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

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struct load_info {
	Elf_Ehdr *hdr;
	unsigned long len;
	Elf_Shdr *sechdrs;
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	char *secstrings, *strtab;
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	unsigned long symoffs, stroffs;
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	struct _ddebug *debug;
	unsigned int num_debug;
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	bool sig_ok;
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	struct {
		unsigned int sym, str, mod, vers, info, pcpu;
	} index;
};

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

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static inline void add_taint_module(struct module *mod, unsigned flag,
				    enum lockdep_ok lockdep_ok)
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{
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	add_taint(flag, lockdep_ok);
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	mod->taints |= (1U << flag);
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}

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/*
 * A thread that wants to hold a reference to a module only while it
 * is running can call this to safely exit.  nfsd and lockd use this.
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 */
void __module_put_and_exit(struct module *mod, long code)
{
	module_put(mod);
	do_exit(code);
}
EXPORT_SYMBOL(__module_put_and_exit);
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/* Find a module section: 0 means not found. */
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static unsigned int find_sec(const struct load_info *info, const char *name)
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{
	unsigned int i;

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

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

/* Find a module section, or NULL.  Fill in number of "objects" in section. */
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static void *section_objs(const struct load_info *info,
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			  const char *name,
			  size_t object_size,
			  unsigned int *num)
{
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	unsigned int sec = find_sec(info, name);
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	/* Section 0 has sh_addr 0 and sh_size 0. */
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	*num = info->sechdrs[sec].sh_size / object_size;
	return (void *)info->sechdrs[sec].sh_addr;
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}

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/* Provided by the linker */
extern const struct kernel_symbol __start___ksymtab[];
extern const struct kernel_symbol __stop___ksymtab[];
extern const struct kernel_symbol __start___ksymtab_gpl[];
extern const struct kernel_symbol __stop___ksymtab_gpl[];
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extern const struct kernel_symbol __start___ksymtab_gpl_future[];
extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
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extern const unsigned long __start___kcrctab[];
extern const unsigned long __start___kcrctab_gpl[];
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extern const unsigned long __start___kcrctab_gpl_future[];
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#ifdef CONFIG_UNUSED_SYMBOLS
extern const struct kernel_symbol __start___ksymtab_unused[];
extern const struct kernel_symbol __stop___ksymtab_unused[];
extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
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extern const unsigned long __start___kcrctab_unused[];
extern const unsigned long __start___kcrctab_unused_gpl[];
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#endif
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#ifndef CONFIG_MODVERSIONS
#define symversion(base, idx) NULL
#else
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#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
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#endif

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static bool each_symbol_in_section(const struct symsearch *arr,
				   unsigned int arrsize,
				   struct module *owner,
				   bool (*fn)(const struct symsearch *syms,
					      struct module *owner,
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					      void *data),
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				   void *data)
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{
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	unsigned int j;
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	for (j = 0; j < arrsize; j++) {
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		if (fn(&arr[j], owner, data))
			return true;
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	}
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	return false;
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}

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/* Returns true as soon as fn returns true, otherwise false. */
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bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
				    struct module *owner,
				    void *data),
			 void *data)
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{
	struct module *mod;
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	static const struct symsearch arr[] = {
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		{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
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		  NOT_GPL_ONLY, false },
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		{ __start___ksymtab_gpl, __stop___ksymtab_gpl,
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		  __start___kcrctab_gpl,
		  GPL_ONLY, false },
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		{ __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
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		  __start___kcrctab_gpl_future,
		  WILL_BE_GPL_ONLY, false },
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#ifdef CONFIG_UNUSED_SYMBOLS
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		{ __start___ksymtab_unused, __stop___ksymtab_unused,
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		  __start___kcrctab_unused,
		  NOT_GPL_ONLY, true },
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		{ __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
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		  __start___kcrctab_unused_gpl,
		  GPL_ONLY, true },
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#endif
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	};
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	module_assert_mutex_or_preempt();

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	if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
		return true;
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	list_for_each_entry_rcu(mod, &modules, list) {
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		struct symsearch arr[] = {
			{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
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			  NOT_GPL_ONLY, false },
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			{ mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
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			  mod->gpl_crcs,
			  GPL_ONLY, false },
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			{ mod->gpl_future_syms,
			  mod->gpl_future_syms + mod->num_gpl_future_syms,
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			  mod->gpl_future_crcs,
			  WILL_BE_GPL_ONLY, false },
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#ifdef CONFIG_UNUSED_SYMBOLS
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			{ mod->unused_syms,
			  mod->unused_syms + mod->num_unused_syms,
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			  mod->unused_crcs,
			  NOT_GPL_ONLY, true },
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			{ mod->unused_gpl_syms,
			  mod->unused_gpl_syms + mod->num_unused_gpl_syms,
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			  mod->unused_gpl_crcs,
			  GPL_ONLY, true },
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#endif
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		};

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

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		if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
			return true;
	}
	return false;
}
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EXPORT_SYMBOL_GPL(each_symbol_section);
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struct find_symbol_arg {
	/* Input */
	const char *name;
	bool gplok;
	bool warn;

	/* Output */
	struct module *owner;
	const unsigned long *crc;
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	const struct kernel_symbol *sym;
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};

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static bool check_symbol(const struct symsearch *syms,
				 struct module *owner,
				 unsigned int symnum, void *data)
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{
	struct find_symbol_arg *fsa = data;

	if (!fsa->gplok) {
		if (syms->licence == GPL_ONLY)
			return false;
		if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
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			pr_warn("Symbol %s is being used by a non-GPL module, "
				"which will not be allowed in the future\n",
				fsa->name);
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		}
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	}
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#ifdef CONFIG_UNUSED_SYMBOLS
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	if (syms->unused && fsa->warn) {
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		pr_warn("Symbol %s is marked as UNUSED, however this module is "
			"using it.\n", fsa->name);
		pr_warn("This symbol will go away in the future.\n");
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		pr_warn("Please evaluate if this is the right api to use and "
			"if it really is, submit a report to the linux kernel "
			"mailing list together with submitting your code for "
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			"inclusion.\n");
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	}
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#endif
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	fsa->owner = owner;
	fsa->crc = symversion(syms->crcs, symnum);
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	fsa->sym = &syms->start[symnum];
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	return true;
}

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static int cmp_name(const void *va, const void *vb)
{
	const char *a;
	const struct kernel_symbol *b;
	a = va; b = vb;
	return strcmp(a, b->name);
}

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static bool find_symbol_in_section(const struct symsearch *syms,
				   struct module *owner,
				   void *data)
{
	struct find_symbol_arg *fsa = data;
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	struct kernel_symbol *sym;

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

	if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
		return true;
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	return false;
}

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/* Find a symbol and return it, along with, (optional) crc and
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 * (optional) module which owns it.  Needs preempt disabled or module_mutex. */
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const struct kernel_symbol *find_symbol(const char *name,
					struct module **owner,
					const unsigned long **crc,
					bool gplok,
					bool warn)
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{
	struct find_symbol_arg fsa;

	fsa.name = name;
	fsa.gplok = gplok;
	fsa.warn = warn;

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	if (each_symbol_section(find_symbol_in_section, &fsa)) {
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		if (owner)
			*owner = fsa.owner;
		if (crc)
			*crc = fsa.crc;
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		return fsa.sym;
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	}

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	pr_debug("Failed to find symbol %s\n", name);
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	return NULL;
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}
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EXPORT_SYMBOL_GPL(find_symbol);
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/*
 * Search for module by name: must hold module_mutex (or preempt disabled
 * for read-only access).
 */
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static struct module *find_module_all(const char *name, size_t len,
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				      bool even_unformed)
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{
	struct module *mod;

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	module_assert_mutex_or_preempt();
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	list_for_each_entry(mod, &modules, list) {
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		if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
			continue;
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		if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
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			return mod;
	}
	return NULL;
}
624 625 626

struct module *find_module(const char *name)
{
627
	module_assert_mutex();
628
	return find_module_all(name, strlen(name), false);
629
}
630
EXPORT_SYMBOL_GPL(find_module);
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631 632

#ifdef CONFIG_SMP
633

634
static inline void __percpu *mod_percpu(struct module *mod)
635
{
636 637
	return mod->percpu;
}
638

639
static int percpu_modalloc(struct module *mod, struct load_info *info)
640
{
641 642 643 644 645 646
	Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
	unsigned long align = pcpusec->sh_addralign;

	if (!pcpusec->sh_size)
		return 0;

647
	if (align > PAGE_SIZE) {
648 649
		pr_warn("%s: per-cpu alignment %li > %li\n",
			mod->name, align, PAGE_SIZE);
650 651 652
		align = PAGE_SIZE;
	}

653
	mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
654
	if (!mod->percpu) {
655 656
		pr_warn("%s: Could not allocate %lu bytes percpu data\n",
			mod->name, (unsigned long)pcpusec->sh_size);
657 658
		return -ENOMEM;
	}
659
	mod->percpu_size = pcpusec->sh_size;
660
	return 0;
661 662
}

663
static void percpu_modfree(struct module *mod)
664
{
665
	free_percpu(mod->percpu);
666 667
}

668
static unsigned int find_pcpusec(struct load_info *info)
669
{
670
	return find_sec(info, ".data..percpu");
671 672
}

673 674
static void percpu_modcopy(struct module *mod,
			   const void *from, unsigned long size)
675 676 677 678
{
	int cpu;

	for_each_possible_cpu(cpu)
679
		memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
680 681
}

682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698
/**
 * 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.
 *
 * RETURNS:
 * %true if @addr is from module static percpu area
 */
bool is_module_percpu_address(unsigned long addr)
{
	struct module *mod;
	unsigned int cpu;

	preempt_disable();

	list_for_each_entry_rcu(mod, &modules, list) {
699 700
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
701 702 703 704 705 706 707 708 709 710 711 712 713 714 715
		if (!mod->percpu_size)
			continue;
		for_each_possible_cpu(cpu) {
			void *start = per_cpu_ptr(mod->percpu, cpu);

			if ((void *)addr >= start &&
			    (void *)addr < start + mod->percpu_size) {
				preempt_enable();
				return true;
			}
		}
	}

	preempt_enable();
	return false;
716 717
}

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718
#else /* ... !CONFIG_SMP */
719

720
static inline void __percpu *mod_percpu(struct module *mod)
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721 722 723
{
	return NULL;
}
724
static int percpu_modalloc(struct module *mod, struct load_info *info)
725
{
726 727 728 729
	/* 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;
730 731
}
static inline void percpu_modfree(struct module *mod)
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732 733
{
}
734
static unsigned int find_pcpusec(struct load_info *info)
L
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735 736 737
{
	return 0;
}
738 739
static inline void percpu_modcopy(struct module *mod,
				  const void *from, unsigned long size)
L
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740 741 742 743
{
	/* pcpusec should be 0, and size of that section should be 0. */
	BUG_ON(size != 0);
}
744 745 746 747
bool is_module_percpu_address(unsigned long addr)
{
	return false;
}
748

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#endif /* CONFIG_SMP */

751 752 753 754 755 756
#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,   \
757
			struct module_kobject *mk, char *buffer)      \
758
{                                                                     \
759
	return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field);  \
760 761 762 763 764 765 766
}                                                                     \
static int modinfo_##field##_exists(struct module *mod)               \
{                                                                     \
	return mod->field != NULL;                                    \
}                                                                     \
static void free_modinfo_##field(struct module *mod)                  \
{                                                                     \
767 768
	kfree(mod->field);                                            \
	mod->field = NULL;                                            \
769 770
}                                                                     \
static struct module_attribute modinfo_##field = {                    \
771
	.attr = { .name = __stringify(field), .mode = 0444 },         \
772 773 774 775 776 777 778 779 780
	.show = show_modinfo_##field,                                 \
	.setup = setup_modinfo_##field,                               \
	.test = modinfo_##field##_exists,                             \
	.free = free_modinfo_##field,                                 \
};

MODINFO_ATTR(version);
MODINFO_ATTR(srcversion);

781 782
static char last_unloaded_module[MODULE_NAME_LEN+1];

783
#ifdef CONFIG_MODULE_UNLOAD
784 785 786

EXPORT_TRACEPOINT_SYMBOL(module_get);

787 788 789
/* MODULE_REF_BASE is the base reference count by kmodule loader. */
#define MODULE_REF_BASE	1

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790
/* Init the unload section of the module. */
791
static int module_unload_init(struct module *mod)
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792
{
793 794 795 796 797
	/*
	 * Initialize reference counter to MODULE_REF_BASE.
	 * refcnt == 0 means module is going.
	 */
	atomic_set(&mod->refcnt, MODULE_REF_BASE);
798

799 800
	INIT_LIST_HEAD(&mod->source_list);
	INIT_LIST_HEAD(&mod->target_list);
801

L
Linus Torvalds 已提交
802
	/* Hold reference count during initialization. */
803
	atomic_inc(&mod->refcnt);
804 805

	return 0;
L
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806 807 808 809 810 811 812
}

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

813 814
	list_for_each_entry(use, &b->source_list, source_list) {
		if (use->source == a) {
815
			pr_debug("%s uses %s!\n", a->name, b->name);
L
Linus Torvalds 已提交
816 817 818
			return 1;
		}
	}
819
	pr_debug("%s does not use %s!\n", a->name, b->name);
L
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820 821 822
	return 0;
}

823 824 825 826 827 828 829 830 831 832 833
/*
 * 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;

834
	pr_debug("Allocating new usage for %s.\n", a->name);
835 836
	use = kmalloc(sizeof(*use), GFP_ATOMIC);
	if (!use) {
837
		pr_warn("%s: out of memory loading\n", a->name);
838 839 840 841 842 843 844 845 846 847
		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;
}

848
/* Module a uses b: caller needs module_mutex() */
849
int ref_module(struct module *a, struct module *b)
L
Linus Torvalds 已提交
850
{
851
	int err;
K
Kay Sievers 已提交
852

853
	if (b == NULL || already_uses(a, b))
854 855
		return 0;

856 857
	/* If module isn't available, we fail. */
	err = strong_try_module_get(b);
858
	if (err)
859
		return err;
L
Linus Torvalds 已提交
860

861 862
	err = add_module_usage(a, b);
	if (err) {
L
Linus Torvalds 已提交
863
		module_put(b);
864
		return err;
L
Linus Torvalds 已提交
865
	}
866
	return 0;
L
Linus Torvalds 已提交
867
}
868
EXPORT_SYMBOL_GPL(ref_module);
L
Linus Torvalds 已提交
869 870 871 872

/* Clear the unload stuff of the module. */
static void module_unload_free(struct module *mod)
{
873
	struct module_use *use, *tmp;
L
Linus Torvalds 已提交
874

875
	mutex_lock(&module_mutex);
876 877
	list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
		struct module *i = use->target;
878
		pr_debug("%s unusing %s\n", mod->name, i->name);
879 880 881 882
		module_put(i);
		list_del(&use->source_list);
		list_del(&use->target_list);
		kfree(use);
L
Linus Torvalds 已提交
883
	}
884
	mutex_unlock(&module_mutex);
L
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885 886 887
}

#ifdef CONFIG_MODULE_FORCE_UNLOAD
888
static inline int try_force_unload(unsigned int flags)
L
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889 890 891
{
	int ret = (flags & O_TRUNC);
	if (ret)
892
		add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
L
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893 894 895
	return ret;
}
#else
896
static inline int try_force_unload(unsigned int flags)
L
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897 898 899 900 901
{
	return 0;
}
#endif /* CONFIG_MODULE_FORCE_UNLOAD */

902 903
/* Try to release refcount of module, 0 means success. */
static int try_release_module_ref(struct module *mod)
L
Linus Torvalds 已提交
904
{
905
	int ret;
L
Linus Torvalds 已提交
906

907 908 909 910 911 912
	/* 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);
L
Linus Torvalds 已提交
913

914 915
	return ret;
}
L
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916

917 918
static int try_stop_module(struct module *mod, int flags, int *forced)
{
919
	/* If it's not unused, quit unless we're forcing. */
920 921 922
	if (try_release_module_ref(mod) != 0) {
		*forced = try_force_unload(flags);
		if (!(*forced))
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923 924 925 926
			return -EWOULDBLOCK;
	}

	/* Mark it as dying. */
927
	mod->state = MODULE_STATE_GOING;
L
Linus Torvalds 已提交
928

929
	return 0;
L
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930 931
}

932 933 934 935 936 937 938 939 940 941
/**
 * module_refcount - return the refcount or -1 if unloading
 *
 * @mod:	the module we're checking
 *
 * Returns:
 *	-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)
L
Linus Torvalds 已提交
942
{
943
	return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
L
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944 945 946 947 948 949
}
EXPORT_SYMBOL(module_refcount);

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

950 951
SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
		unsigned int, flags)
L
Linus Torvalds 已提交
952 953
{
	struct module *mod;
954
	char name[MODULE_NAME_LEN];
L
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955 956
	int ret, forced = 0;

957
	if (!capable(CAP_SYS_MODULE) || modules_disabled)
958 959 960 961 962 963
		return -EPERM;

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

964 965
	if (mutex_lock_interruptible(&module_mutex) != 0)
		return -EINTR;
L
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966 967 968 969 970 971 972

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

973
	if (!list_empty(&mod->source_list)) {
L
Linus Torvalds 已提交
974 975 976 977 978 979 980
		/* 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) {
981
		/* FIXME: if (force), slam module count damn the torpedoes */
982
		pr_debug("%s already dying\n", mod->name);
L
Linus Torvalds 已提交
983 984 985 986 987
		ret = -EBUSY;
		goto out;
	}

	/* If it has an init func, it must have an exit func to unload */
988
	if (mod->init && !mod->exit) {
989
		forced = try_force_unload(flags);
L
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990 991 992 993 994 995 996 997 998 999 1000 1001
		if (!forced) {
			/* This module can't be removed */
			ret = -EBUSY;
			goto out;
		}
	}

	/* Stop the machine so refcounts can't move and disable module. */
	ret = try_stop_module(mod, flags, &forced);
	if (ret != 0)
		goto out;

1002
	mutex_unlock(&module_mutex);
L
Lucas De Marchi 已提交
1003
	/* Final destruction now no one is using it. */
1004
	if (mod->exit != NULL)
L
Linus Torvalds 已提交
1005
		mod->exit();
1006 1007
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
1008
	async_synchronize_full();
1009

1010
	/* Store the name of the last unloaded module for diagnostic purposes */
1011
	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
L
Linus Torvalds 已提交
1012

1013 1014 1015
	free_module(mod);
	return 0;
out:
1016
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
1017 1018 1019
	return ret;
}

1020
static inline void print_unload_info(struct seq_file *m, struct module *mod)
L
Linus Torvalds 已提交
1021 1022 1023 1024
{
	struct module_use *use;
	int printed_something = 0;

1025
	seq_printf(m, " %i ", module_refcount(mod));
L
Linus Torvalds 已提交
1026

1027 1028 1029 1030
	/*
	 * Always include a trailing , so userspace can differentiate
	 * between this and the old multi-field proc format.
	 */
1031
	list_for_each_entry(use, &mod->source_list, source_list) {
L
Linus Torvalds 已提交
1032
		printed_something = 1;
1033
		seq_printf(m, "%s,", use->source->name);
L
Linus Torvalds 已提交
1034 1035 1036 1037
	}

	if (mod->init != NULL && mod->exit == NULL) {
		printed_something = 1;
1038
		seq_puts(m, "[permanent],");
L
Linus Torvalds 已提交
1039 1040 1041
	}

	if (!printed_something)
1042
		seq_puts(m, "-");
L
Linus Torvalds 已提交
1043 1044 1045 1046 1047 1048
}

void __symbol_put(const char *symbol)
{
	struct module *owner;

1049
	preempt_disable();
1050
	if (!find_symbol(symbol, &owner, NULL, true, false))
L
Linus Torvalds 已提交
1051 1052
		BUG();
	module_put(owner);
1053
	preempt_enable();
L
Linus Torvalds 已提交
1054 1055 1056
}
EXPORT_SYMBOL(__symbol_put);

1057
/* Note this assumes addr is a function, which it currently always is. */
L
Linus Torvalds 已提交
1058 1059
void symbol_put_addr(void *addr)
{
1060
	struct module *modaddr;
1061
	unsigned long a = (unsigned long)dereference_function_descriptor(addr);
L
Linus Torvalds 已提交
1062

1063
	if (core_kernel_text(a))
1064
		return;
L
Linus Torvalds 已提交
1065

1066 1067
	/* module_text_address is safe here: we're supposed to have reference
	 * to module from symbol_get, so it can't go away. */
1068
	modaddr = __module_text_address(a);
1069
	BUG_ON(!modaddr);
1070
	module_put(modaddr);
L
Linus Torvalds 已提交
1071 1072 1073 1074
}
EXPORT_SYMBOL_GPL(symbol_put_addr);

static ssize_t show_refcnt(struct module_attribute *mattr,
1075
			   struct module_kobject *mk, char *buffer)
L
Linus Torvalds 已提交
1076
{
1077
	return sprintf(buffer, "%i\n", module_refcount(mk->mod));
L
Linus Torvalds 已提交
1078 1079
}

1080 1081
static struct module_attribute modinfo_refcnt =
	__ATTR(refcnt, 0444, show_refcnt, NULL);
L
Linus Torvalds 已提交
1082

1083 1084 1085 1086
void __module_get(struct module *module)
{
	if (module) {
		preempt_disable();
1087
		atomic_inc(&module->refcnt);
1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099
		trace_module_get(module, _RET_IP_);
		preempt_enable();
	}
}
EXPORT_SYMBOL(__module_get);

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

	if (module) {
		preempt_disable();
1100 1101 1102
		/* Note: here, we can fail to get a reference */
		if (likely(module_is_live(module) &&
			   atomic_inc_not_zero(&module->refcnt) != 0))
1103
			trace_module_get(module, _RET_IP_);
1104
		else
1105 1106 1107 1108 1109 1110 1111 1112
			ret = false;

		preempt_enable();
	}
	return ret;
}
EXPORT_SYMBOL(try_module_get);

1113 1114
void module_put(struct module *module)
{
1115 1116
	int ret;

1117
	if (module) {
1118
		preempt_disable();
1119 1120
		ret = atomic_dec_if_positive(&module->refcnt);
		WARN_ON(ret < 0);	/* Failed to put refcount */
1121
		trace_module_put(module, _RET_IP_);
1122
		preempt_enable();
1123 1124 1125 1126
	}
}
EXPORT_SYMBOL(module_put);

L
Linus Torvalds 已提交
1127
#else /* !CONFIG_MODULE_UNLOAD */
1128
static inline void print_unload_info(struct seq_file *m, struct module *mod)
L
Linus Torvalds 已提交
1129 1130
{
	/* We don't know the usage count, or what modules are using. */
1131
	seq_puts(m, " - -");
L
Linus Torvalds 已提交
1132 1133 1134 1135 1136 1137
}

static inline void module_unload_free(struct module *mod)
{
}

1138
int ref_module(struct module *a, struct module *b)
L
Linus Torvalds 已提交
1139
{
1140
	return strong_try_module_get(b);
L
Linus Torvalds 已提交
1141
}
1142
EXPORT_SYMBOL_GPL(ref_module);
L
Linus Torvalds 已提交
1143

1144
static inline int module_unload_init(struct module *mod)
L
Linus Torvalds 已提交
1145
{
1146
	return 0;
L
Linus Torvalds 已提交
1147 1148 1149
}
#endif /* CONFIG_MODULE_UNLOAD */

1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161
static size_t module_flags_taint(struct module *mod, char *buf)
{
	size_t l = 0;

	if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
		buf[l++] = 'P';
	if (mod->taints & (1 << TAINT_OOT_MODULE))
		buf[l++] = 'O';
	if (mod->taints & (1 << TAINT_FORCED_MODULE))
		buf[l++] = 'F';
	if (mod->taints & (1 << TAINT_CRAP))
		buf[l++] = 'C';
1162
	if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1163
		buf[l++] = 'E';
1164 1165
	/*
	 * TAINT_FORCED_RMMOD: could be added.
1166
	 * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1167 1168 1169 1170 1171
	 * apply to modules.
	 */
	return l;
}

1172
static ssize_t show_initstate(struct module_attribute *mattr,
1173
			      struct module_kobject *mk, char *buffer)
1174 1175 1176
{
	const char *state = "unknown";

1177
	switch (mk->mod->state) {
1178 1179 1180 1181 1182 1183 1184 1185 1186
	case MODULE_STATE_LIVE:
		state = "live";
		break;
	case MODULE_STATE_COMING:
		state = "coming";
		break;
	case MODULE_STATE_GOING:
		state = "going";
		break;
1187 1188
	default:
		BUG();
1189 1190 1191 1192
	}
	return sprintf(buffer, "%s\n", state);
}

1193 1194
static struct module_attribute modinfo_initstate =
	__ATTR(initstate, 0444, show_initstate, NULL);
1195

1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206
static ssize_t store_uevent(struct module_attribute *mattr,
			    struct module_kobject *mk,
			    const char *buffer, size_t count)
{
	enum kobject_action action;

	if (kobject_action_type(buffer, count, &action) == 0)
		kobject_uevent(&mk->kobj, action);
	return count;
}

1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239
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)
{
	return sprintf(buffer, "%u\n", mk->mod->core_size);
}

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

static ssize_t show_initsize(struct module_attribute *mattr,
			     struct module_kobject *mk, char *buffer)
{
	return sprintf(buffer, "%u\n", mk->mod->init_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, buffer);
	buffer[l++] = '\n';
	return l;
}

static struct module_attribute modinfo_taint =
	__ATTR(taint, 0444, show_taint, NULL);
1240

1241
static struct module_attribute *modinfo_attrs[] = {
1242
	&module_uevent,
1243 1244
	&modinfo_version,
	&modinfo_srcversion,
1245 1246 1247 1248
	&modinfo_initstate,
	&modinfo_coresize,
	&modinfo_initsize,
	&modinfo_taint,
1249
#ifdef CONFIG_MODULE_UNLOAD
1250
	&modinfo_refcnt,
1251 1252 1253 1254
#endif
	NULL,
};

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1255 1256
static const char vermagic[] = VERMAGIC_STRING;

1257
static int try_to_force_load(struct module *mod, const char *reason)
1258 1259
{
#ifdef CONFIG_MODULE_FORCE_LOAD
1260
	if (!test_taint(TAINT_FORCED_MODULE))
1261
		pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1262
	add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1263 1264 1265 1266 1267 1268
	return 0;
#else
	return -ENOEXEC;
#endif
}

L
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1269
#ifdef CONFIG_MODVERSIONS
1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280
/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
static unsigned long maybe_relocated(unsigned long crc,
				     const struct module *crc_owner)
{
#ifdef ARCH_RELOCATES_KCRCTAB
	if (crc_owner == NULL)
		return crc - (unsigned long)reloc_start;
#endif
	return crc;
}

L
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1281 1282 1283
static int check_version(Elf_Shdr *sechdrs,
			 unsigned int versindex,
			 const char *symname,
1284
			 struct module *mod,
1285 1286
			 const unsigned long *crc,
			 const struct module *crc_owner)
L
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1287 1288 1289 1290 1291 1292 1293 1294
{
	unsigned int i, num_versions;
	struct modversion_info *versions;

	/* Exporting module didn't supply crcs?  OK, we're already tainted. */
	if (!crc)
		return 1;

1295 1296 1297 1298
	/* No versions at all?  modprobe --force does this. */
	if (versindex == 0)
		return try_to_force_load(mod, symname) == 0;

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1299 1300 1301 1302 1303 1304 1305 1306
	versions = (void *) sechdrs[versindex].sh_addr;
	num_versions = sechdrs[versindex].sh_size
		/ sizeof(struct modversion_info);

	for (i = 0; i < num_versions; i++) {
		if (strcmp(versions[i].name, symname) != 0)
			continue;

1307
		if (versions[i].crc == maybe_relocated(*crc, crc_owner))
L
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1308
			return 1;
1309
		pr_debug("Found checksum %lX vs module %lX\n",
1310
		       maybe_relocated(*crc, crc_owner), versions[i].crc);
1311
		goto bad_version;
L
Linus Torvalds 已提交
1312
	}
1313

1314
	pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1315
	return 0;
1316 1317

bad_version:
1318
	pr_warn("%s: disagrees about version of symbol %s\n",
1319 1320
	       mod->name, symname);
	return 0;
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1321 1322 1323 1324 1325 1326 1327 1328
}

static inline int check_modstruct_version(Elf_Shdr *sechdrs,
					  unsigned int versindex,
					  struct module *mod)
{
	const unsigned long *crc;

1329 1330 1331 1332 1333
	/*
	 * Since this should be found in kernel (which can't be removed), no
	 * locking is necessary -- use preempt_disable() to placate lockdep.
	 */
	preempt_disable();
1334
	if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1335 1336
			 &crc, true, false)) {
		preempt_enable();
L
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1337
		BUG();
1338 1339
	}
	preempt_enable();
1340 1341
	return check_version(sechdrs, versindex,
			     VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1342
			     NULL);
L
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1343 1344
}

1345 1346 1347
/* First part is kernel version, which we ignore if module has crcs. */
static inline int same_magic(const char *amagic, const char *bmagic,
			     bool has_crcs)
L
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1348
{
1349 1350 1351 1352
	if (has_crcs) {
		amagic += strcspn(amagic, " ");
		bmagic += strcspn(bmagic, " ");
	}
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1353 1354 1355 1356 1357 1358
	return strcmp(amagic, bmagic) == 0;
}
#else
static inline int check_version(Elf_Shdr *sechdrs,
				unsigned int versindex,
				const char *symname,
1359
				struct module *mod,
1360 1361
				const unsigned long *crc,
				const struct module *crc_owner)
L
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1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372
{
	return 1;
}

static inline int check_modstruct_version(Elf_Shdr *sechdrs,
					  unsigned int versindex,
					  struct module *mod)
{
	return 1;
}

1373 1374
static inline int same_magic(const char *amagic, const char *bmagic,
			     bool has_crcs)
L
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1375 1376 1377 1378 1379
{
	return strcmp(amagic, bmagic) == 0;
}
#endif /* CONFIG_MODVERSIONS */

1380
/* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1381 1382
static const struct kernel_symbol *resolve_symbol(struct module *mod,
						  const struct load_info *info,
1383
						  const char *name,
1384
						  char ownername[])
L
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1385 1386
{
	struct module *owner;
1387
	const struct kernel_symbol *sym;
L
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1388
	const unsigned long *crc;
1389
	int err;
L
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1390

1391 1392 1393 1394 1395 1396
	/*
	 * The module_mutex should not be a heavily contended lock;
	 * if we get the occasional sleep here, we'll go an extra iteration
	 * in the wait_event_interruptible(), which is harmless.
	 */
	sched_annotate_sleep();
1397
	mutex_lock(&module_mutex);
1398
	sym = find_symbol(name, &owner, &crc,
1399
			  !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1400 1401 1402
	if (!sym)
		goto unlock;

1403 1404
	if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
			   owner)) {
1405 1406
		sym = ERR_PTR(-EINVAL);
		goto getname;
L
Linus Torvalds 已提交
1407
	}
1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418

	err = ref_module(mod, owner);
	if (err) {
		sym = ERR_PTR(err);
		goto getname;
	}

getname:
	/* We must make copy under the lock if we failed to get ref. */
	strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
unlock:
1419
	mutex_unlock(&module_mutex);
1420
	return sym;
L
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1421 1422
}

1423 1424 1425 1426
static const struct kernel_symbol *
resolve_symbol_wait(struct module *mod,
		    const struct load_info *info,
		    const char *name)
1427 1428
{
	const struct kernel_symbol *ksym;
1429
	char owner[MODULE_NAME_LEN];
1430 1431

	if (wait_event_interruptible_timeout(module_wq,
1432 1433
			!IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
			|| PTR_ERR(ksym) != -EBUSY,
1434
					     30 * HZ) <= 0) {
1435 1436
		pr_warn("%s: gave up waiting for init of module %s.\n",
			mod->name, owner);
1437 1438 1439 1440
	}
	return ksym;
}

L
Linus Torvalds 已提交
1441 1442 1443 1444
/*
 * /sys/module/foo/sections stuff
 * J. Corbet <corbet@lwn.net>
 */
R
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1445
#ifdef CONFIG_SYSFS
1446

R
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1447
#ifdef CONFIG_KALLSYMS
1448 1449 1450 1451 1452
static inline bool sect_empty(const Elf_Shdr *sect)
{
	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
}

1453
struct module_sect_attr {
1454 1455 1456 1457 1458
	struct module_attribute mattr;
	char *name;
	unsigned long address;
};

1459
struct module_sect_attrs {
1460 1461 1462 1463 1464
	struct attribute_group grp;
	unsigned int nsections;
	struct module_sect_attr attrs[0];
};

L
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1465
static ssize_t module_sect_show(struct module_attribute *mattr,
1466
				struct module_kobject *mk, char *buf)
L
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1467 1468 1469
{
	struct module_sect_attr *sattr =
		container_of(mattr, struct module_sect_attr, mattr);
1470
	return sprintf(buf, "0x%pK\n", (void *)sattr->address);
L
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1471 1472
}

1473 1474
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
1475
	unsigned int section;
1476 1477 1478 1479 1480 1481

	for (section = 0; section < sect_attrs->nsections; section++)
		kfree(sect_attrs->attrs[section].name);
	kfree(sect_attrs);
}

R
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1482
static void add_sect_attrs(struct module *mod, const struct load_info *info)
L
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1483 1484 1485 1486 1487
{
	unsigned int nloaded = 0, i, size[2];
	struct module_sect_attrs *sect_attrs;
	struct module_sect_attr *sattr;
	struct attribute **gattr;
1488

L
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1489
	/* Count loaded sections and allocate structures */
R
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1490 1491
	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]))
L
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1492 1493 1494 1495 1496
			nloaded++;
	size[0] = ALIGN(sizeof(*sect_attrs)
			+ nloaded * sizeof(sect_attrs->attrs[0]),
			sizeof(sect_attrs->grp.attrs[0]));
	size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1497 1498
	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
	if (sect_attrs == NULL)
L
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1499 1500 1501 1502 1503 1504
		return;

	/* Setup section attributes. */
	sect_attrs->grp.name = "sections";
	sect_attrs->grp.attrs = (void *)sect_attrs + size[0];

1505
	sect_attrs->nsections = 0;
L
Linus Torvalds 已提交
1506 1507
	sattr = &sect_attrs->attrs[0];
	gattr = &sect_attrs->grp.attrs[0];
R
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1508 1509 1510
	for (i = 0; i < info->hdr->e_shnum; i++) {
		Elf_Shdr *sec = &info->sechdrs[i];
		if (sect_empty(sec))
1511
			continue;
R
Rusty Russell 已提交
1512 1513
		sattr->address = sec->sh_addr;
		sattr->name = kstrdup(info->secstrings + sec->sh_name,
1514 1515 1516 1517
					GFP_KERNEL);
		if (sattr->name == NULL)
			goto out;
		sect_attrs->nsections++;
1518
		sysfs_attr_init(&sattr->mattr.attr);
L
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1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532
		sattr->mattr.show = module_sect_show;
		sattr->mattr.store = NULL;
		sattr->mattr.attr.name = sattr->name;
		sattr->mattr.attr.mode = S_IRUGO;
		*(gattr++) = &(sattr++)->mattr.attr;
	}
	*gattr = NULL;

	if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
		goto out;

	mod->sect_attrs = sect_attrs;
	return;
  out:
1533
	free_sect_attrs(sect_attrs);
L
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1534 1535 1536 1537 1538 1539 1540 1541 1542
}

static void remove_sect_attrs(struct module *mod)
{
	if (mod->sect_attrs) {
		sysfs_remove_group(&mod->mkobj.kobj,
				   &mod->sect_attrs->grp);
		/* We are positive that no one is using any sect attrs
		 * at this point.  Deallocate immediately. */
1543
		free_sect_attrs(mod->sect_attrs);
L
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1544 1545 1546 1547
		mod->sect_attrs = NULL;
	}
}

1548 1549 1550 1551 1552 1553 1554 1555 1556 1557
/*
 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
 */

struct module_notes_attrs {
	struct kobject *dir;
	unsigned int notes;
	struct bin_attribute attrs[0];
};

1558
static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575
				 struct bin_attribute *bin_attr,
				 char *buf, loff_t pos, size_t count)
{
	/*
	 * The caller checked the pos and count against our size.
	 */
	memcpy(buf, bin_attr->private + pos, count);
	return count;
}

static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
			     unsigned int i)
{
	if (notes_attrs->dir) {
		while (i-- > 0)
			sysfs_remove_bin_file(notes_attrs->dir,
					      &notes_attrs->attrs[i]);
1576
		kobject_put(notes_attrs->dir);
1577 1578 1579 1580
	}
	kfree(notes_attrs);
}

R
Rusty Russell 已提交
1581
static void add_notes_attrs(struct module *mod, const struct load_info *info)
1582 1583 1584 1585 1586
{
	unsigned int notes, loaded, i;
	struct module_notes_attrs *notes_attrs;
	struct bin_attribute *nattr;

1587 1588 1589 1590
	/* failed to create section attributes, so can't create notes */
	if (!mod->sect_attrs)
		return;

1591 1592
	/* Count notes sections and allocate structures.  */
	notes = 0;
R
Rusty Russell 已提交
1593 1594 1595
	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]) &&
		    (info->sechdrs[i].sh_type == SHT_NOTE))
1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608
			++notes;

	if (notes == 0)
		return;

	notes_attrs = kzalloc(sizeof(*notes_attrs)
			      + notes * sizeof(notes_attrs->attrs[0]),
			      GFP_KERNEL);
	if (notes_attrs == NULL)
		return;

	notes_attrs->notes = notes;
	nattr = &notes_attrs->attrs[0];
R
Rusty Russell 已提交
1609 1610
	for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
		if (sect_empty(&info->sechdrs[i]))
1611
			continue;
R
Rusty Russell 已提交
1612
		if (info->sechdrs[i].sh_type == SHT_NOTE) {
1613
			sysfs_bin_attr_init(nattr);
1614 1615
			nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
			nattr->attr.mode = S_IRUGO;
R
Rusty Russell 已提交
1616 1617
			nattr->size = info->sechdrs[i].sh_size;
			nattr->private = (void *) info->sechdrs[i].sh_addr;
1618 1619 1620 1621 1622 1623
			nattr->read = module_notes_read;
			++nattr;
		}
		++loaded;
	}

1624
	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645
	if (!notes_attrs->dir)
		goto out;

	for (i = 0; i < notes; ++i)
		if (sysfs_create_bin_file(notes_attrs->dir,
					  &notes_attrs->attrs[i]))
			goto out;

	mod->notes_attrs = notes_attrs;
	return;

  out:
	free_notes_attrs(notes_attrs, i);
}

static void remove_notes_attrs(struct module *mod)
{
	if (mod->notes_attrs)
		free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
}

L
Linus Torvalds 已提交
1646
#else
1647

R
Rusty Russell 已提交
1648 1649
static inline void add_sect_attrs(struct module *mod,
				  const struct load_info *info)
L
Linus Torvalds 已提交
1650 1651 1652 1653 1654 1655
{
}

static inline void remove_sect_attrs(struct module *mod)
{
}
1656

R
Rusty Russell 已提交
1657 1658
static inline void add_notes_attrs(struct module *mod,
				   const struct load_info *info)
1659 1660 1661 1662 1663 1664
{
}

static inline void remove_notes_attrs(struct module *mod)
{
}
R
Rusty Russell 已提交
1665
#endif /* CONFIG_KALLSYMS */
L
Linus Torvalds 已提交
1666

1667 1668 1669 1670 1671 1672
static void add_usage_links(struct module *mod)
{
#ifdef CONFIG_MODULE_UNLOAD
	struct module_use *use;
	int nowarn;

1673
	mutex_lock(&module_mutex);
1674 1675 1676 1677
	list_for_each_entry(use, &mod->target_list, target_list) {
		nowarn = sysfs_create_link(use->target->holders_dir,
					   &mod->mkobj.kobj, mod->name);
	}
1678
	mutex_unlock(&module_mutex);
1679 1680 1681 1682 1683 1684 1685 1686
#endif
}

static void del_usage_links(struct module *mod)
{
#ifdef CONFIG_MODULE_UNLOAD
	struct module_use *use;

1687
	mutex_lock(&module_mutex);
1688 1689
	list_for_each_entry(use, &mod->target_list, target_list)
		sysfs_remove_link(use->target->holders_dir, mod->name);
1690
	mutex_unlock(&module_mutex);
1691 1692 1693
#endif
}

1694
static int module_add_modinfo_attrs(struct module *mod)
1695 1696
{
	struct module_attribute *attr;
1697
	struct module_attribute *temp_attr;
1698 1699 1700
	int error = 0;
	int i;

1701 1702 1703 1704 1705 1706 1707
	mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
					(ARRAY_SIZE(modinfo_attrs) + 1)),
					GFP_KERNEL);
	if (!mod->modinfo_attrs)
		return -ENOMEM;

	temp_attr = mod->modinfo_attrs;
1708 1709
	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
		if (!attr->test ||
1710 1711
		    (attr->test && attr->test(mod))) {
			memcpy(temp_attr, attr, sizeof(*temp_attr));
1712
			sysfs_attr_init(&temp_attr->attr);
1713 1714
			error = sysfs_create_file(&mod->mkobj.kobj,
					&temp_attr->attr);
1715 1716
			++temp_attr;
		}
1717 1718 1719 1720
	}
	return error;
}

1721
static void module_remove_modinfo_attrs(struct module *mod)
1722 1723 1724 1725
{
	struct module_attribute *attr;
	int i;

1726 1727 1728 1729
	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
		/* pick a field to test for end of list */
		if (!attr->attr.name)
			break;
1730
		sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1731 1732
		if (attr->free)
			attr->free(mod);
1733
	}
1734
	kfree(mod->modinfo_attrs);
1735
}
L
Linus Torvalds 已提交
1736

1737 1738 1739 1740 1741 1742 1743 1744
static void mod_kobject_put(struct module *mod)
{
	DECLARE_COMPLETION_ONSTACK(c);
	mod->mkobj.kobj_completion = &c;
	kobject_put(&mod->mkobj.kobj);
	wait_for_completion(&c);
}

1745
static int mod_sysfs_init(struct module *mod)
L
Linus Torvalds 已提交
1746 1747
{
	int err;
1748
	struct kobject *kobj;
L
Linus Torvalds 已提交
1749

1750
	if (!module_sysfs_initialized) {
1751
		pr_err("%s: module sysfs not initialized\n", mod->name);
1752 1753 1754
		err = -EINVAL;
		goto out;
	}
1755 1756 1757

	kobj = kset_find_obj(module_kset, mod->name);
	if (kobj) {
1758
		pr_err("%s: module is already loaded\n", mod->name);
1759 1760 1761 1762 1763
		kobject_put(kobj);
		err = -EINVAL;
		goto out;
	}

L
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1764
	mod->mkobj.mod = mod;
1765

1766 1767 1768 1769 1770
	memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
	mod->mkobj.kobj.kset = module_kset;
	err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
				   "%s", mod->name);
	if (err)
1771
		mod_kobject_put(mod);
K
Kay Sievers 已提交
1772

1773
	/* delay uevent until full sysfs population */
K
Kay Sievers 已提交
1774 1775 1776 1777
out:
	return err;
}

1778
static int mod_sysfs_setup(struct module *mod,
R
Rusty Russell 已提交
1779
			   const struct load_info *info,
K
Kay Sievers 已提交
1780 1781 1782 1783 1784
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	int err;

1785 1786 1787 1788
	err = mod_sysfs_init(mod);
	if (err)
		goto out;

1789
	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1790 1791
	if (!mod->holders_dir) {
		err = -ENOMEM;
K
Kay Sievers 已提交
1792
		goto out_unreg;
1793
	}
K
Kay Sievers 已提交
1794

L
Linus Torvalds 已提交
1795 1796
	err = module_param_sysfs_setup(mod, kparam, num_params);
	if (err)
K
Kay Sievers 已提交
1797
		goto out_unreg_holders;
L
Linus Torvalds 已提交
1798

1799 1800
	err = module_add_modinfo_attrs(mod);
	if (err)
1801
		goto out_unreg_param;
1802

1803
	add_usage_links(mod);
R
Rusty Russell 已提交
1804 1805
	add_sect_attrs(mod, info);
	add_notes_attrs(mod, info);
1806

1807
	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
L
Linus Torvalds 已提交
1808 1809
	return 0;

1810 1811
out_unreg_param:
	module_param_sysfs_remove(mod);
K
Kay Sievers 已提交
1812
out_unreg_holders:
1813
	kobject_put(mod->holders_dir);
K
Kay Sievers 已提交
1814
out_unreg:
1815
	mod_kobject_put(mod);
1816
out:
L
Linus Torvalds 已提交
1817 1818
	return err;
}
1819 1820 1821

static void mod_sysfs_fini(struct module *mod)
{
R
Rusty Russell 已提交
1822 1823
	remove_notes_attrs(mod);
	remove_sect_attrs(mod);
1824
	mod_kobject_put(mod);
1825 1826
}

1827 1828 1829 1830
static void init_param_lock(struct module *mod)
{
	mutex_init(&mod->param_lock);
}
R
Rusty Russell 已提交
1831
#else /* !CONFIG_SYSFS */
1832

R
Rusty Russell 已提交
1833 1834
static int mod_sysfs_setup(struct module *mod,
			   const struct load_info *info,
1835 1836 1837 1838 1839 1840
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	return 0;
}

1841 1842 1843 1844
static void mod_sysfs_fini(struct module *mod)
{
}

1845 1846 1847 1848
static void module_remove_modinfo_attrs(struct module *mod)
{
}

1849 1850 1851 1852
static void del_usage_links(struct module *mod)
{
}

1853 1854 1855
static void init_param_lock(struct module *mod)
{
}
1856
#endif /* CONFIG_SYSFS */
L
Linus Torvalds 已提交
1857

1858
static void mod_sysfs_teardown(struct module *mod)
L
Linus Torvalds 已提交
1859
{
1860
	del_usage_links(mod);
1861
	module_remove_modinfo_attrs(mod);
L
Linus Torvalds 已提交
1862
	module_param_sysfs_remove(mod);
1863 1864
	kobject_put(mod->mkobj.drivers_dir);
	kobject_put(mod->holders_dir);
1865
	mod_sysfs_fini(mod);
L
Linus Torvalds 已提交
1866 1867
}

1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911
#ifdef CONFIG_DEBUG_SET_MODULE_RONX
/*
 * LKM RO/NX protection: protect module's text/ro-data
 * from modification and any data from execution.
 */
void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
{
	unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
	unsigned long end_pfn = PFN_DOWN((unsigned long)end);

	if (end_pfn > begin_pfn)
		set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
}

static void set_section_ro_nx(void *base,
			unsigned long text_size,
			unsigned long ro_size,
			unsigned long total_size)
{
	/* begin and end PFNs of the current subsection */
	unsigned long begin_pfn;
	unsigned long end_pfn;

	/*
	 * Set RO for module text and RO-data:
	 * - Always protect first page.
	 * - Do not protect last partial page.
	 */
	if (ro_size > 0)
		set_page_attributes(base, base + ro_size, set_memory_ro);

	/*
	 * Set NX permissions for module data:
	 * - Do not protect first partial page.
	 * - Always protect last page.
	 */
	if (total_size > text_size) {
		begin_pfn = PFN_UP((unsigned long)base + text_size);
		end_pfn = PFN_UP((unsigned long)base + total_size);
		if (end_pfn > begin_pfn)
			set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
	}
}

1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929
static void unset_module_core_ro_nx(struct module *mod)
{
	set_page_attributes(mod->module_core + mod->core_text_size,
		mod->module_core + mod->core_size,
		set_memory_x);
	set_page_attributes(mod->module_core,
		mod->module_core + mod->core_ro_size,
		set_memory_rw);
}

static void unset_module_init_ro_nx(struct module *mod)
{
	set_page_attributes(mod->module_init + mod->init_text_size,
		mod->module_init + mod->init_size,
		set_memory_x);
	set_page_attributes(mod->module_init,
		mod->module_init + mod->init_ro_size,
		set_memory_rw);
1930 1931 1932
}

/* Iterate through all modules and set each module's text as RW */
1933
void set_all_modules_text_rw(void)
1934 1935 1936 1937 1938
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1939 1940
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955
		if ((mod->module_core) && (mod->core_text_size)) {
			set_page_attributes(mod->module_core,
						mod->module_core + mod->core_text_size,
						set_memory_rw);
		}
		if ((mod->module_init) && (mod->init_text_size)) {
			set_page_attributes(mod->module_init,
						mod->module_init + mod->init_text_size,
						set_memory_rw);
		}
	}
	mutex_unlock(&module_mutex);
}

/* Iterate through all modules and set each module's text as RO */
1956
void set_all_modules_text_ro(void)
1957 1958 1959 1960 1961
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1962 1963
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978
		if ((mod->module_core) && (mod->core_text_size)) {
			set_page_attributes(mod->module_core,
						mod->module_core + mod->core_text_size,
						set_memory_ro);
		}
		if ((mod->module_init) && (mod->init_text_size)) {
			set_page_attributes(mod->module_init,
						mod->module_init + mod->init_text_size,
						set_memory_ro);
		}
	}
	mutex_unlock(&module_mutex);
}
#else
static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1979 1980
static void unset_module_core_ro_nx(struct module *mod) { }
static void unset_module_init_ro_nx(struct module *mod) { }
1981 1982
#endif

1983
void __weak module_memfree(void *module_region)
1984 1985 1986 1987 1988 1989 1990 1991
{
	vfree(module_region);
}

void __weak module_arch_cleanup(struct module *mod)
{
}

1992 1993 1994 1995
void __weak module_arch_freeing_init(struct module *mod)
{
}

1996
/* Free a module, remove from lists, etc. */
L
Linus Torvalds 已提交
1997 1998
static void free_module(struct module *mod)
{
1999 2000
	trace_module_free(mod);

2001
	mod_sysfs_teardown(mod);
L
Linus Torvalds 已提交
2002

2003 2004
	/* We leave it in list to prevent duplicate loads, but make sure
	 * that noone uses it while it's being deconstructed. */
2005
	mutex_lock(&module_mutex);
2006
	mod->state = MODULE_STATE_UNFORMED;
2007
	mutex_unlock(&module_mutex);
2008

2009 2010 2011
	/* Remove dynamic debug info */
	ddebug_remove_module(mod->name);

L
Linus Torvalds 已提交
2012 2013 2014 2015 2016 2017
	/* Arch-specific cleanup. */
	module_arch_cleanup(mod);

	/* Module unload stuff */
	module_unload_free(mod);

2018 2019 2020
	/* Free any allocated parameters. */
	destroy_params(mod->kp, mod->num_kp);

2021 2022
	/* Now we can delete it from the lists */
	mutex_lock(&module_mutex);
2023 2024
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
2025
	mod_tree_remove(mod);
2026
	/* Remove this module from bug list, this uses list_del_rcu */
2027
	module_bug_cleanup(mod);
2028 2029
	/* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
	synchronize_sched();
2030 2031
	mutex_unlock(&module_mutex);

L
Linus Torvalds 已提交
2032
	/* This may be NULL, but that's OK */
2033
	unset_module_init_ro_nx(mod);
2034
	module_arch_freeing_init(mod);
2035
	module_memfree(mod->module_init);
L
Linus Torvalds 已提交
2036
	kfree(mod->args);
2037
	percpu_modfree(mod);
2038

2039
	/* Free lock-classes; relies on the preceding sync_rcu(). */
I
Ingo Molnar 已提交
2040 2041
	lockdep_free_key_range(mod->module_core, mod->core_size);

L
Linus Torvalds 已提交
2042
	/* Finally, free the core (containing the module structure) */
2043
	unset_module_core_ro_nx(mod);
2044
	module_memfree(mod->module_core);
2045 2046 2047 2048

#ifdef CONFIG_MPU
	update_protections(current->mm);
#endif
L
Linus Torvalds 已提交
2049 2050 2051 2052 2053
}

void *__symbol_get(const char *symbol)
{
	struct module *owner;
2054
	const struct kernel_symbol *sym;
L
Linus Torvalds 已提交
2055

2056
	preempt_disable();
2057 2058 2059
	sym = find_symbol(symbol, &owner, NULL, true, true);
	if (sym && strong_try_module_get(owner))
		sym = NULL;
2060
	preempt_enable();
L
Linus Torvalds 已提交
2061

2062
	return sym ? (void *)sym->value : NULL;
L
Linus Torvalds 已提交
2063 2064 2065
}
EXPORT_SYMBOL_GPL(__symbol_get);

2066 2067
/*
 * Ensure that an exported symbol [global namespace] does not already exist
2068
 * in the kernel or in some other module's exported symbol table.
2069 2070
 *
 * You must hold the module_mutex.
2071 2072 2073
 */
static int verify_export_symbols(struct module *mod)
{
2074
	unsigned int i;
2075
	struct module *owner;
2076 2077 2078 2079 2080 2081 2082 2083
	const struct kernel_symbol *s;
	struct {
		const struct kernel_symbol *sym;
		unsigned int num;
	} arr[] = {
		{ mod->syms, mod->num_syms },
		{ mod->gpl_syms, mod->num_gpl_syms },
		{ mod->gpl_future_syms, mod->num_gpl_future_syms },
2084
#ifdef CONFIG_UNUSED_SYMBOLS
2085 2086
		{ mod->unused_syms, mod->num_unused_syms },
		{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2087
#endif
2088
	};
2089

2090 2091
	for (i = 0; i < ARRAY_SIZE(arr); i++) {
		for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2092
			if (find_symbol(s->name, &owner, NULL, true, false)) {
2093
				pr_err("%s: exports duplicate symbol %s"
2094 2095 2096 2097
				       " (owned by %s)\n",
				       mod->name, s->name, module_name(owner));
				return -ENOEXEC;
			}
2098
		}
2099 2100
	}
	return 0;
2101 2102
}

2103
/* Change all symbols so that st_value encodes the pointer directly. */
2104 2105 2106 2107
static int simplify_symbols(struct module *mod, const struct load_info *info)
{
	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
	Elf_Sym *sym = (void *)symsec->sh_addr;
L
Linus Torvalds 已提交
2108
	unsigned long secbase;
2109
	unsigned int i;
L
Linus Torvalds 已提交
2110
	int ret = 0;
2111
	const struct kernel_symbol *ksym;
L
Linus Torvalds 已提交
2112

2113 2114 2115
	for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
		const char *name = info->strtab + sym[i].st_name;

L
Linus Torvalds 已提交
2116 2117
		switch (sym[i].st_shndx) {
		case SHN_COMMON:
2118 2119 2120 2121
			/* Ignore common symbols */
			if (!strncmp(name, "__gnu_lto", 9))
				break;

L
Linus Torvalds 已提交
2122 2123
			/* We compiled with -fno-common.  These are not
			   supposed to happen.  */
2124
			pr_debug("Common symbol: %s\n", name);
2125
			pr_warn("%s: please compile with -fno-common\n",
L
Linus Torvalds 已提交
2126 2127 2128 2129 2130 2131
			       mod->name);
			ret = -ENOEXEC;
			break;

		case SHN_ABS:
			/* Don't need to do anything */
2132
			pr_debug("Absolute symbol: 0x%08lx\n",
L
Linus Torvalds 已提交
2133 2134 2135 2136
			       (long)sym[i].st_value);
			break;

		case SHN_UNDEF:
2137
			ksym = resolve_symbol_wait(mod, info, name);
L
Linus Torvalds 已提交
2138
			/* Ok if resolved.  */
2139
			if (ksym && !IS_ERR(ksym)) {
2140
				sym[i].st_value = ksym->value;
L
Linus Torvalds 已提交
2141
				break;
2142 2143
			}

L
Linus Torvalds 已提交
2144
			/* Ok if weak.  */
2145
			if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
L
Linus Torvalds 已提交
2146 2147
				break;

2148 2149
			pr_warn("%s: Unknown symbol %s (err %li)\n",
				mod->name, name, PTR_ERR(ksym));
2150
			ret = PTR_ERR(ksym) ?: -ENOENT;
L
Linus Torvalds 已提交
2151 2152 2153 2154
			break;

		default:
			/* Divert to percpu allocation if a percpu var. */
2155
			if (sym[i].st_shndx == info->index.pcpu)
2156
				secbase = (unsigned long)mod_percpu(mod);
L
Linus Torvalds 已提交
2157
			else
2158
				secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
L
Linus Torvalds 已提交
2159 2160 2161 2162 2163 2164 2165 2166
			sym[i].st_value += secbase;
			break;
		}
	}

	return ret;
}

2167
static int apply_relocations(struct module *mod, const struct load_info *info)
2168 2169 2170 2171 2172
{
	unsigned int i;
	int err = 0;

	/* Now do relocations. */
2173 2174
	for (i = 1; i < info->hdr->e_shnum; i++) {
		unsigned int infosec = info->sechdrs[i].sh_info;
2175 2176

		/* Not a valid relocation section? */
2177
		if (infosec >= info->hdr->e_shnum)
2178 2179 2180
			continue;

		/* Don't bother with non-allocated sections */
2181
		if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2182 2183
			continue;

2184 2185 2186 2187 2188 2189
		if (info->sechdrs[i].sh_type == SHT_REL)
			err = apply_relocate(info->sechdrs, info->strtab,
					     info->index.sym, i, mod);
		else if (info->sechdrs[i].sh_type == SHT_RELA)
			err = apply_relocate_add(info->sechdrs, info->strtab,
						 info->index.sym, i, mod);
2190 2191 2192 2193 2194 2195
		if (err < 0)
			break;
	}
	return err;
}

2196 2197 2198 2199 2200 2201 2202 2203
/* Additional bytes needed by arch in front of individual sections */
unsigned int __weak arch_mod_section_prepend(struct module *mod,
					     unsigned int section)
{
	/* default implementation just returns zero */
	return 0;
}

L
Linus Torvalds 已提交
2204
/* Update size with this section: return offset. */
2205 2206
static long get_offset(struct module *mod, unsigned int *size,
		       Elf_Shdr *sechdr, unsigned int section)
L
Linus Torvalds 已提交
2207 2208 2209
{
	long ret;

2210
	*size += arch_mod_section_prepend(mod, section);
L
Linus Torvalds 已提交
2211 2212 2213 2214 2215 2216 2217 2218 2219
	ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
	*size = ret + sechdr->sh_size;
	return ret;
}

/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
   might -- code, read-only data, read-write data, small data.  Tally
   sizes, and place the offsets into sh_entsize fields: high bit means it
   belongs in init. */
2220
static void layout_sections(struct module *mod, struct load_info *info)
L
Linus Torvalds 已提交
2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232
{
	static unsigned long const masks[][2] = {
		/* NOTE: all executable code must be the first section
		 * in this array; otherwise modify the text_size
		 * finder in the two loops below */
		{ SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
		{ SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
		{ SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
		{ ARCH_SHF_SMALL | SHF_ALLOC, 0 }
	};
	unsigned int m, i;

2233 2234
	for (i = 0; i < info->hdr->e_shnum; i++)
		info->sechdrs[i].sh_entsize = ~0UL;
L
Linus Torvalds 已提交
2235

2236
	pr_debug("Core section allocation order:\n");
L
Linus Torvalds 已提交
2237
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2238 2239 2240
		for (i = 0; i < info->hdr->e_shnum; ++i) {
			Elf_Shdr *s = &info->sechdrs[i];
			const char *sname = info->secstrings + s->sh_name;
L
Linus Torvalds 已提交
2241 2242 2243 2244

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2245
			    || strstarts(sname, ".init"))
L
Linus Torvalds 已提交
2246
				continue;
2247
			s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2248
			pr_debug("\t%s\n", sname);
L
Linus Torvalds 已提交
2249
		}
2250 2251 2252
		switch (m) {
		case 0: /* executable */
			mod->core_size = debug_align(mod->core_size);
L
Linus Torvalds 已提交
2253
			mod->core_text_size = mod->core_size;
2254 2255 2256 2257 2258 2259 2260 2261 2262
			break;
		case 1: /* RO: text and ro-data */
			mod->core_size = debug_align(mod->core_size);
			mod->core_ro_size = mod->core_size;
			break;
		case 3: /* whole core */
			mod->core_size = debug_align(mod->core_size);
			break;
		}
L
Linus Torvalds 已提交
2263 2264
	}

2265
	pr_debug("Init section allocation order:\n");
L
Linus Torvalds 已提交
2266
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2267 2268 2269
		for (i = 0; i < info->hdr->e_shnum; ++i) {
			Elf_Shdr *s = &info->sechdrs[i];
			const char *sname = info->secstrings + s->sh_name;
L
Linus Torvalds 已提交
2270 2271 2272 2273

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2274
			    || !strstarts(sname, ".init"))
L
Linus Torvalds 已提交
2275
				continue;
2276
			s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
L
Linus Torvalds 已提交
2277
					 | INIT_OFFSET_MASK);
2278
			pr_debug("\t%s\n", sname);
L
Linus Torvalds 已提交
2279
		}
2280 2281 2282
		switch (m) {
		case 0: /* executable */
			mod->init_size = debug_align(mod->init_size);
L
Linus Torvalds 已提交
2283
			mod->init_text_size = mod->init_size;
2284 2285 2286 2287 2288 2289 2290 2291 2292
			break;
		case 1: /* RO: text and ro-data */
			mod->init_size = debug_align(mod->init_size);
			mod->init_ro_size = mod->init_size;
			break;
		case 3: /* whole init */
			mod->init_size = debug_align(mod->init_size);
			break;
		}
L
Linus Torvalds 已提交
2293 2294 2295 2296 2297 2298 2299 2300
	}
}

static void set_license(struct module *mod, const char *license)
{
	if (!license)
		license = "unspecified";

2301
	if (!license_is_gpl_compatible(license)) {
2302
		if (!test_taint(TAINT_PROPRIETARY_MODULE))
2303 2304
			pr_warn("%s: module license '%s' taints kernel.\n",
				mod->name, license);
2305 2306
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
L
Linus Torvalds 已提交
2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328
	}
}

/* Parse tag=value strings from .modinfo section */
static char *next_string(char *string, unsigned long *secsize)
{
	/* Skip non-zero chars */
	while (string[0]) {
		string++;
		if ((*secsize)-- <= 1)
			return NULL;
	}

	/* Skip any zero padding. */
	while (!string[0]) {
		string++;
		if ((*secsize)-- <= 1)
			return NULL;
	}
	return string;
}

2329
static char *get_modinfo(struct load_info *info, const char *tag)
L
Linus Torvalds 已提交
2330 2331 2332
{
	char *p;
	unsigned int taglen = strlen(tag);
2333 2334
	Elf_Shdr *infosec = &info->sechdrs[info->index.info];
	unsigned long size = infosec->sh_size;
L
Linus Torvalds 已提交
2335

2336
	for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
L
Linus Torvalds 已提交
2337 2338 2339 2340 2341 2342
		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
			return p + taglen + 1;
	}
	return NULL;
}

2343
static void setup_modinfo(struct module *mod, struct load_info *info)
2344 2345 2346 2347 2348 2349
{
	struct module_attribute *attr;
	int i;

	for (i = 0; (attr = modinfo_attrs[i]); i++) {
		if (attr->setup)
2350
			attr->setup(mod, get_modinfo(info, attr->attr.name));
2351 2352 2353
	}
}

2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364
static void free_modinfo(struct module *mod)
{
	struct module_attribute *attr;
	int i;

	for (i = 0; (attr = modinfo_attrs[i]); i++) {
		if (attr->free)
			attr->free(mod);
	}
}

L
Linus Torvalds 已提交
2365
#ifdef CONFIG_KALLSYMS
2366 2367 2368 2369 2370 2371

/* lookup symbol in given range of kernel_symbols */
static const struct kernel_symbol *lookup_symbol(const char *name,
	const struct kernel_symbol *start,
	const struct kernel_symbol *stop)
{
2372 2373
	return bsearch(name, start, stop - start,
			sizeof(struct kernel_symbol), cmp_name);
2374 2375
}

2376 2377
static int is_exported(const char *name, unsigned long value,
		       const struct module *mod)
L
Linus Torvalds 已提交
2378
{
2379 2380 2381
	const struct kernel_symbol *ks;
	if (!mod)
		ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2382
	else
2383 2384
		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
	return ks != NULL && ks->value == value;
L
Linus Torvalds 已提交
2385 2386 2387
}

/* As per nm */
2388
static char elf_type(const Elf_Sym *sym, const struct load_info *info)
L
Linus Torvalds 已提交
2389
{
2390 2391
	const Elf_Shdr *sechdrs = info->sechdrs;

L
Linus Torvalds 已提交
2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420
	if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
		if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
			return 'v';
		else
			return 'w';
	}
	if (sym->st_shndx == SHN_UNDEF)
		return 'U';
	if (sym->st_shndx == SHN_ABS)
		return 'a';
	if (sym->st_shndx >= SHN_LORESERVE)
		return '?';
	if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
		return 't';
	if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
	    && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
		if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
			return 'r';
		else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
			return 'g';
		else
			return 'd';
	}
	if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
		if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
			return 's';
		else
			return 'b';
	}
2421 2422
	if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
		      ".debug")) {
L
Linus Torvalds 已提交
2423
		return 'n';
2424
	}
L
Linus Torvalds 已提交
2425 2426 2427
	return '?';
}

2428
static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2429
			unsigned int shnum)
2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448
{
	const Elf_Shdr *sec;

	if (src->st_shndx == SHN_UNDEF
	    || src->st_shndx >= shnum
	    || !src->st_name)
		return false;

	sec = sechdrs + src->st_shndx;
	if (!(sec->sh_flags & SHF_ALLOC)
#ifndef CONFIG_KALLSYMS_ALL
	    || !(sec->sh_flags & SHF_EXECINSTR)
#endif
	    || (sec->sh_entsize & INIT_OFFSET_MASK))
		return false;

	return true;
}

2449 2450 2451 2452 2453 2454 2455
/*
 * We only allocate and copy the strings needed by the parts of symtab
 * we keep.  This is simple, but has the effect of making multiple
 * copies of duplicates.  We could be more sophisticated, see
 * linux-kernel thread starting with
 * <73defb5e4bca04a6431392cc341112b1@localhost>.
 */
2456
static void layout_symtab(struct module *mod, struct load_info *info)
2457
{
2458 2459
	Elf_Shdr *symsect = info->sechdrs + info->index.sym;
	Elf_Shdr *strsect = info->sechdrs + info->index.str;
2460
	const Elf_Sym *src;
2461
	unsigned int i, nsrc, ndst, strtab_size = 0;
2462 2463 2464 2465

	/* Put symbol section at end of init part of module. */
	symsect->sh_flags |= SHF_ALLOC;
	symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2466
					 info->index.sym) | INIT_OFFSET_MASK;
2467
	pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2468

2469
	src = (void *)info->hdr + symsect->sh_offset;
2470
	nsrc = symsect->sh_size / sizeof(*src);
2471

2472
	/* Compute total space required for the core symbols' strtab. */
2473 2474 2475 2476
	for (ndst = i = 0; i < nsrc; i++) {
		if (i == 0 ||
		    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
			strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2477
			ndst++;
2478
		}
2479
	}
2480 2481

	/* Append room for core symbols at end of core part. */
2482
	info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2483 2484
	info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
	mod->core_size += strtab_size;
2485
	mod->core_size = debug_align(mod->core_size);
2486

2487 2488 2489
	/* Put string table section at end of init part of module. */
	strsect->sh_flags |= SHF_ALLOC;
	strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2490
					 info->index.str) | INIT_OFFSET_MASK;
2491
	mod->init_size = debug_align(mod->init_size);
2492
	pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2493 2494
}

2495
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2496
{
2497 2498 2499
	unsigned int i, ndst;
	const Elf_Sym *src;
	Elf_Sym *dst;
2500
	char *s;
2501
	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
L
Linus Torvalds 已提交
2502

2503 2504
	mod->symtab = (void *)symsec->sh_addr;
	mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2505 2506
	/* Make sure we get permanent strtab: don't use info->strtab. */
	mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
L
Linus Torvalds 已提交
2507 2508 2509

	/* Set types up while we still have access to sections. */
	for (i = 0; i < mod->num_symtab; i++)
2510
		mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2511

2512
	mod->core_symtab = dst = mod->module_core + info->symoffs;
2513
	mod->core_strtab = s = mod->module_core + info->stroffs;
2514
	src = mod->symtab;
2515 2516 2517 2518 2519 2520 2521 2522
	for (ndst = i = 0; i < mod->num_symtab; i++) {
		if (i == 0 ||
		    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
			dst[ndst] = src[i];
			dst[ndst++].st_name = s - mod->core_strtab;
			s += strlcpy(s, &mod->strtab[src[i].st_name],
				     KSYM_NAME_LEN) + 1;
		}
2523 2524
	}
	mod->core_num_syms = ndst;
L
Linus Torvalds 已提交
2525 2526
}
#else
2527
static inline void layout_symtab(struct module *mod, struct load_info *info)
2528 2529
{
}
2530

2531
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2532 2533 2534 2535
{
}
#endif /* CONFIG_KALLSYMS */

2536
static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2537
{
2538 2539
	if (!debug)
		return;
2540 2541
#ifdef CONFIG_DYNAMIC_DEBUG
	if (ddebug_add_module(debug, num, debug->modname))
2542 2543
		pr_err("dynamic debug error adding module: %s\n",
			debug->modname);
2544
#endif
2545
}
2546

2547 2548 2549 2550 2551 2552
static void dynamic_debug_remove(struct _ddebug *debug)
{
	if (debug)
		ddebug_remove_module(debug->modname);
}

2553 2554
void * __weak module_alloc(unsigned long size)
{
2555
	return vmalloc_exec(size);
2556 2557
}

2558
#ifdef CONFIG_DEBUG_KMEMLEAK
2559 2560
static void kmemleak_load_module(const struct module *mod,
				 const struct load_info *info)
2561 2562 2563 2564
{
	unsigned int i;

	/* only scan the sections containing data */
2565
	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2566

2567
	for (i = 1; i < info->hdr->e_shnum; i++) {
2568 2569 2570 2571
		/* Scan all writable sections that's not executable */
		if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
		    !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
		    (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2572 2573
			continue;

2574 2575
		kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
				   info->sechdrs[i].sh_size, GFP_KERNEL);
2576 2577 2578
	}
}
#else
2579 2580
static inline void kmemleak_load_module(const struct module *mod,
					const struct load_info *info)
2581 2582 2583 2584
{
}
#endif

2585
#ifdef CONFIG_MODULE_SIG
2586
static int module_sig_check(struct load_info *info)
2587 2588
{
	int err = -ENOKEY;
2589 2590
	const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
	const void *mod = info->hdr;
2591

2592 2593
	if (info->len > markerlen &&
	    memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2594
		/* We truncate the module to discard the signature */
2595 2596
		info->len -= markerlen;
		err = mod_verify_sig(mod, &info->len);
2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610
	}

	if (!err) {
		info->sig_ok = true;
		return 0;
	}

	/* Not having a signature is only an error if we're strict. */
	if (err == -ENOKEY && !sig_enforce)
		err = 0;

	return err;
}
#else /* !CONFIG_MODULE_SIG */
2611
static int module_sig_check(struct load_info *info)
2612 2613 2614 2615 2616
{
	return 0;
}
#endif /* !CONFIG_MODULE_SIG */

2617 2618
/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
static int elf_header_check(struct load_info *info)
2619
{
2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632
	if (info->len < sizeof(*(info->hdr)))
		return -ENOEXEC;

	if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
	    || info->hdr->e_type != ET_REL
	    || !elf_check_arch(info->hdr)
	    || info->hdr->e_shentsize != sizeof(Elf_Shdr))
		return -ENOEXEC;

	if (info->hdr->e_shoff >= info->len
	    || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
		info->len - info->hdr->e_shoff))
		return -ENOEXEC;
2633

2634 2635 2636
	return 0;
}

2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653
#define COPY_CHUNK_SIZE (16*PAGE_SIZE)

static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
{
	do {
		unsigned long n = min(len, COPY_CHUNK_SIZE);

		if (copy_from_user(dst, usrc, n) != 0)
			return -EFAULT;
		cond_resched();
		dst += n;
		usrc += n;
		len -= n;
	} while (len);
	return 0;
}

2654 2655 2656
/* Sets info->hdr and info->len. */
static int copy_module_from_user(const void __user *umod, unsigned long len,
				  struct load_info *info)
2657 2658 2659
{
	int err;

2660 2661
	info->len = len;
	if (info->len < sizeof(*(info->hdr)))
2662 2663
		return -ENOEXEC;

2664 2665 2666 2667
	err = security_kernel_module_from_file(NULL);
	if (err)
		return err;

2668
	/* Suck in entire file: we'll want most of it. */
2669 2670
	info->hdr = __vmalloc(info->len,
			GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2671
	if (!info->hdr)
2672 2673
		return -ENOMEM;

2674
	if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2675 2676
		vfree(info->hdr);
		return -EFAULT;
2677 2678
	}

2679 2680 2681 2682 2683 2684
	return 0;
}

/* Sets info->hdr and info->len. */
static int copy_module_from_fd(int fd, struct load_info *info)
{
2685
	struct fd f = fdget(fd);
2686 2687 2688 2689 2690
	int err;
	struct kstat stat;
	loff_t pos;
	ssize_t bytes = 0;

2691
	if (!f.file)
2692 2693
		return -ENOEXEC;

2694
	err = security_kernel_module_from_file(f.file);
2695
	if (err)
2696
		goto out;
2697

2698
	err = vfs_getattr(&f.file->f_path, &stat);
2699
	if (err)
2700
		goto out;
2701

2702 2703 2704
	if (stat.size > INT_MAX) {
		err = -EFBIG;
		goto out;
2705
	}
2706 2707 2708 2709 2710 2711 2712

	/* Don't hand 0 to vmalloc, it whines. */
	if (stat.size == 0) {
		err = -EINVAL;
		goto out;
	}

2713 2714 2715 2716
	info->hdr = vmalloc(stat.size);
	if (!info->hdr) {
		err = -ENOMEM;
		goto out;
2717
	}
2718

2719 2720
	pos = 0;
	while (pos < stat.size) {
2721
		bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732
				    stat.size - pos);
		if (bytes < 0) {
			vfree(info->hdr);
			err = bytes;
			goto out;
		}
		if (bytes == 0)
			break;
		pos += bytes;
	}
	info->len = pos;
2733

2734
out:
2735
	fdput(f);
2736 2737 2738
	return err;
}

2739 2740 2741 2742 2743
static void free_copy(struct load_info *info)
{
	vfree(info->hdr);
}

2744
static int rewrite_section_headers(struct load_info *info, int flags)
2745 2746 2747 2748 2749 2750 2751 2752 2753 2754
{
	unsigned int i;

	/* This should always be true, but let's be sure. */
	info->sechdrs[0].sh_addr = 0;

	for (i = 1; i < info->hdr->e_shnum; i++) {
		Elf_Shdr *shdr = &info->sechdrs[i];
		if (shdr->sh_type != SHT_NOBITS
		    && info->len < shdr->sh_offset + shdr->sh_size) {
2755
			pr_err("Module len %lu truncated\n", info->len);
2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768
			return -ENOEXEC;
		}

		/* Mark all sections sh_addr with their address in the
		   temporary image. */
		shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;

#ifndef CONFIG_MODULE_UNLOAD
		/* Don't load .exit sections */
		if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
			shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
#endif
	}
2769 2770

	/* Track but don't keep modinfo and version sections. */
2771 2772 2773 2774
	if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
		info->index.vers = 0; /* Pretend no __versions section! */
	else
		info->index.vers = find_sec(info, "__versions");
2775
	info->index.info = find_sec(info, ".modinfo");
2776 2777
	info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
	info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2778 2779 2780
	return 0;
}

L
Linus Torvalds 已提交
2781 2782 2783 2784 2785 2786 2787 2788
/*
 * Set up our basic convenience variables (pointers to section headers,
 * search for module section index etc), and do some basic section
 * verification.
 *
 * Return the temporary module pointer (we'll replace it with the final
 * one when we move the module sections around).
 */
2789
static struct module *setup_load_info(struct load_info *info, int flags)
L
Linus Torvalds 已提交
2790 2791
{
	unsigned int i;
2792
	int err;
L
Linus Torvalds 已提交
2793 2794 2795 2796
	struct module *mod;

	/* Set up the convenience variables */
	info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2797 2798
	info->secstrings = (void *)info->hdr
		+ info->sechdrs[info->hdr->e_shstrndx].sh_offset;
L
Linus Torvalds 已提交
2799

2800
	err = rewrite_section_headers(info, flags);
2801 2802
	if (err)
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2803

2804 2805
	/* Find internal symbols and strings. */
	for (i = 1; i < info->hdr->e_shnum; i++) {
L
Linus Torvalds 已提交
2806 2807 2808
		if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
			info->index.sym = i;
			info->index.str = info->sechdrs[i].sh_link;
2809 2810 2811
			info->strtab = (char *)info->hdr
				+ info->sechdrs[info->index.str].sh_offset;
			break;
L
Linus Torvalds 已提交
2812 2813 2814
		}
	}

2815
	info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
L
Linus Torvalds 已提交
2816
	if (!info->index.mod) {
2817
		pr_warn("No module found in object\n");
L
Linus Torvalds 已提交
2818 2819 2820 2821 2822 2823
		return ERR_PTR(-ENOEXEC);
	}
	/* This is temporary: point mod into copy of data. */
	mod = (void *)info->sechdrs[info->index.mod].sh_addr;

	if (info->index.sym == 0) {
2824
		pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
L
Linus Torvalds 已提交
2825 2826 2827
		return ERR_PTR(-ENOEXEC);
	}

2828
	info->index.pcpu = find_pcpusec(info);
L
Linus Torvalds 已提交
2829 2830 2831 2832 2833 2834 2835 2836

	/* Check module struct version now, before we try to use module. */
	if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
		return ERR_PTR(-ENOEXEC);

	return mod;
}

2837
static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2838
{
2839
	const char *modmagic = get_modinfo(info, "vermagic");
2840 2841
	int err;

2842 2843 2844
	if (flags & MODULE_INIT_IGNORE_VERMAGIC)
		modmagic = NULL;

2845 2846 2847 2848 2849
	/* This is allowed: modprobe --force will invalidate it. */
	if (!modmagic) {
		err = try_to_force_load(mod, "bad vermagic");
		if (err)
			return err;
2850
	} else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2851
		pr_err("%s: version magic '%s' should be '%s'\n",
2852 2853 2854 2855
		       mod->name, modmagic, vermagic);
		return -ENOEXEC;
	}

2856
	if (!get_modinfo(info, "intree"))
2857
		add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2858

2859
	if (get_modinfo(info, "staging")) {
2860
		add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2861 2862
		pr_warn("%s: module is from the staging directory, the quality "
			"is unknown, you have been warned.\n", mod->name);
2863
	}
2864 2865

	/* Set up license info based on the info section */
2866
	set_license(mod, get_modinfo(info, "license"));
2867

2868 2869 2870
	return 0;
}

2871
static int find_module_sections(struct module *mod, struct load_info *info)
2872
{
2873
	mod->kp = section_objs(info, "__param",
2874
			       sizeof(*mod->kp), &mod->num_kp);
2875
	mod->syms = section_objs(info, "__ksymtab",
2876
				 sizeof(*mod->syms), &mod->num_syms);
2877 2878
	mod->crcs = section_addr(info, "__kcrctab");
	mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2879 2880
				     sizeof(*mod->gpl_syms),
				     &mod->num_gpl_syms);
2881 2882
	mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
	mod->gpl_future_syms = section_objs(info,
2883 2884 2885
					    "__ksymtab_gpl_future",
					    sizeof(*mod->gpl_future_syms),
					    &mod->num_gpl_future_syms);
2886
	mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2887 2888

#ifdef CONFIG_UNUSED_SYMBOLS
2889
	mod->unused_syms = section_objs(info, "__ksymtab_unused",
2890 2891
					sizeof(*mod->unused_syms),
					&mod->num_unused_syms);
2892 2893
	mod->unused_crcs = section_addr(info, "__kcrctab_unused");
	mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2894 2895
					    sizeof(*mod->unused_gpl_syms),
					    &mod->num_unused_gpl_syms);
2896
	mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2897 2898
#endif
#ifdef CONFIG_CONSTRUCTORS
2899
	mod->ctors = section_objs(info, ".ctors",
2900
				  sizeof(*mod->ctors), &mod->num_ctors);
2901 2902 2903 2904 2905 2906 2907 2908
	if (!mod->ctors)
		mod->ctors = section_objs(info, ".init_array",
				sizeof(*mod->ctors), &mod->num_ctors);
	else if (find_sec(info, ".init_array")) {
		/*
		 * This shouldn't happen with same compiler and binutils
		 * building all parts of the module.
		 */
2909
		pr_warn("%s: has both .ctors and .init_array.\n",
2910 2911 2912
		       mod->name);
		return -EINVAL;
	}
2913 2914 2915
#endif

#ifdef CONFIG_TRACEPOINTS
2916 2917 2918
	mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
					     sizeof(*mod->tracepoints_ptrs),
					     &mod->num_tracepoints);
2919
#endif
2920 2921 2922 2923 2924
#ifdef HAVE_JUMP_LABEL
	mod->jump_entries = section_objs(info, "__jump_table",
					sizeof(*mod->jump_entries),
					&mod->num_jump_entries);
#endif
2925
#ifdef CONFIG_EVENT_TRACING
2926
	mod->trace_events = section_objs(info, "_ftrace_events",
2927 2928
					 sizeof(*mod->trace_events),
					 &mod->num_trace_events);
2929 2930 2931
	mod->trace_enums = section_objs(info, "_ftrace_enum_map",
					sizeof(*mod->trace_enums),
					&mod->num_trace_enums);
2932
#endif
2933 2934 2935 2936 2937
#ifdef CONFIG_TRACING
	mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
					 sizeof(*mod->trace_bprintk_fmt_start),
					 &mod->num_trace_bprintk_fmt);
#endif
2938 2939
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
	/* sechdrs[0].sh_size is always zero */
2940
	mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2941 2942 2943
					     sizeof(*mod->ftrace_callsites),
					     &mod->num_ftrace_callsites);
#endif
2944

2945 2946 2947
	mod->extable = section_objs(info, "__ex_table",
				    sizeof(*mod->extable), &mod->num_exentries);

2948
	if (section_addr(info, "__obsparm"))
2949
		pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2950 2951 2952

	info->debug = section_objs(info, "__verbose",
				   sizeof(*info->debug), &info->num_debug);
2953 2954

	return 0;
2955 2956
}

2957
static int move_module(struct module *mod, struct load_info *info)
2958 2959 2960 2961 2962
{
	int i;
	void *ptr;

	/* Do the allocs. */
2963
	ptr = module_alloc(mod->core_size);
2964 2965 2966 2967 2968 2969 2970
	/*
	 * The pointer to this block is stored in the module structure
	 * which is inside the block. Just mark it as not being a
	 * leak.
	 */
	kmemleak_not_leak(ptr);
	if (!ptr)
2971
		return -ENOMEM;
2972 2973 2974 2975

	memset(ptr, 0, mod->core_size);
	mod->module_core = ptr;

2976
	if (mod->init_size) {
2977
		ptr = module_alloc(mod->init_size);
2978 2979 2980 2981 2982 2983 2984 2985
		/*
		 * The pointer to this block is stored in the module structure
		 * which is inside the block. This block doesn't need to be
		 * scanned as it contains data and code that will be freed
		 * after the module is initialized.
		 */
		kmemleak_ignore(ptr);
		if (!ptr) {
2986
			module_memfree(mod->module_core);
2987 2988 2989 2990 2991 2992
			return -ENOMEM;
		}
		memset(ptr, 0, mod->init_size);
		mod->module_init = ptr;
	} else
		mod->module_init = NULL;
2993 2994

	/* Transfer each section which specifies SHF_ALLOC */
2995
	pr_debug("final section addresses:\n");
2996
	for (i = 0; i < info->hdr->e_shnum; i++) {
2997
		void *dest;
2998
		Elf_Shdr *shdr = &info->sechdrs[i];
2999

3000
		if (!(shdr->sh_flags & SHF_ALLOC))
3001 3002
			continue;

3003
		if (shdr->sh_entsize & INIT_OFFSET_MASK)
3004
			dest = mod->module_init
3005
				+ (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3006
		else
3007
			dest = mod->module_core + shdr->sh_entsize;
3008

3009 3010
		if (shdr->sh_type != SHT_NOBITS)
			memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3011
		/* Update sh_addr to point to copy in image. */
3012
		shdr->sh_addr = (unsigned long)dest;
3013 3014
		pr_debug("\t0x%lx %s\n",
			 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3015
	}
3016 3017

	return 0;
3018 3019
}

3020
static int check_module_license_and_versions(struct module *mod)
3021 3022 3023 3024 3025 3026 3027
{
	/*
	 * ndiswrapper is under GPL by itself, but loads proprietary modules.
	 * Don't use add_taint_module(), as it would prevent ndiswrapper from
	 * using GPL-only symbols it needs.
	 */
	if (strcmp(mod->name, "ndiswrapper") == 0)
3028
		add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3029 3030 3031

	/* driverloader was caught wrongly pretending to be under GPL */
	if (strcmp(mod->name, "driverloader") == 0)
3032 3033
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
3034

3035 3036
	/* lve claims to be GPL but upstream won't provide source */
	if (strcmp(mod->name, "lve") == 0)
3037 3038
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
3039

3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078
#ifdef CONFIG_MODVERSIONS
	if ((mod->num_syms && !mod->crcs)
	    || (mod->num_gpl_syms && !mod->gpl_crcs)
	    || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
#ifdef CONFIG_UNUSED_SYMBOLS
	    || (mod->num_unused_syms && !mod->unused_crcs)
	    || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
#endif
		) {
		return try_to_force_load(mod,
					 "no versions for exported symbols");
	}
#endif
	return 0;
}

static void flush_module_icache(const struct module *mod)
{
	mm_segment_t old_fs;

	/* flush the icache in correct context */
	old_fs = get_fs();
	set_fs(KERNEL_DS);

	/*
	 * Flush the instruction cache, since we've played with text.
	 * Do it before processing of module parameters, so the module
	 * can provide parameter accessor functions of its own.
	 */
	if (mod->module_init)
		flush_icache_range((unsigned long)mod->module_init,
				   (unsigned long)mod->module_init
				   + mod->init_size);
	flush_icache_range((unsigned long)mod->module_core,
			   (unsigned long)mod->module_core + mod->core_size);

	set_fs(old_fs);
}

3079 3080 3081 3082 3083 3084 3085 3086
int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
				     Elf_Shdr *sechdrs,
				     char *secstrings,
				     struct module *mod)
{
	return 0;
}

3087
static struct module *layout_and_allocate(struct load_info *info, int flags)
L
Linus Torvalds 已提交
3088
{
3089
	/* Module within temporary copy. */
L
Linus Torvalds 已提交
3090
	struct module *mod;
3091
	int err;
3092

3093
	mod = setup_load_info(info, flags);
3094 3095
	if (IS_ERR(mod))
		return mod;
L
Linus Torvalds 已提交
3096

3097
	err = check_modinfo(mod, info, flags);
3098 3099
	if (err)
		return ERR_PTR(err);
L
Linus Torvalds 已提交
3100 3101

	/* Allow arches to frob section contents and sizes.  */
3102 3103
	err = module_frob_arch_sections(info->hdr, info->sechdrs,
					info->secstrings, mod);
L
Linus Torvalds 已提交
3104
	if (err < 0)
3105
		return ERR_PTR(err);
L
Linus Torvalds 已提交
3106

3107 3108
	/* We will do a special allocation for per-cpu sections later. */
	info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
L
Linus Torvalds 已提交
3109 3110 3111 3112

	/* Determine total sizes, and put offsets in sh_entsize.  For now
	   this is done generically; there doesn't appear to be any
	   special cases for the architectures. */
3113 3114
	layout_sections(mod, info);
	layout_symtab(mod, info);
L
Linus Torvalds 已提交
3115

3116
	/* Allocate and move to the final place */
3117
	err = move_module(mod, info);
3118
	if (err)
3119
		return ERR_PTR(err);
3120 3121 3122

	/* Module has been copied to its final place now: return it. */
	mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3123
	kmemleak_load_module(mod, info);
3124 3125 3126 3127 3128 3129 3130
	return mod;
}

/* mod is no longer valid after this! */
static void module_deallocate(struct module *mod, struct load_info *info)
{
	percpu_modfree(mod);
3131
	module_arch_freeing_init(mod);
3132 3133
	module_memfree(mod->module_init);
	module_memfree(mod->module_core);
3134 3135
}

3136 3137 3138 3139 3140 3141 3142
int __weak module_finalize(const Elf_Ehdr *hdr,
			   const Elf_Shdr *sechdrs,
			   struct module *me)
{
	return 0;
}

3143 3144
static int post_relocation(struct module *mod, const struct load_info *info)
{
3145
	/* Sort exception table now relocations are done. */
3146 3147 3148 3149 3150 3151
	sort_extable(mod->extable, mod->extable + mod->num_exentries);

	/* Copy relocated percpu area over. */
	percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
		       info->sechdrs[info->index.pcpu].sh_size);

3152
	/* Setup kallsyms-specific fields. */
3153 3154 3155 3156 3157 3158
	add_kallsyms(mod, info);

	/* Arch-specific module finalizing. */
	return module_finalize(info->hdr, info->sechdrs, mod);
}

3159 3160 3161 3162 3163 3164
/* Is this module of this name done loading?  No locks held. */
static bool finished_loading(const char *name)
{
	struct module *mod;
	bool ret;

3165 3166 3167 3168 3169 3170
	/*
	 * The module_mutex should not be a heavily contended lock;
	 * if we get the occasional sleep here, we'll go an extra iteration
	 * in the wait_event_interruptible(), which is harmless.
	 */
	sched_annotate_sleep();
3171
	mutex_lock(&module_mutex);
3172
	mod = find_module_all(name, strlen(name), true);
3173 3174
	ret = !mod || mod->state == MODULE_STATE_LIVE
		|| mod->state == MODULE_STATE_GOING;
3175 3176 3177 3178 3179
	mutex_unlock(&module_mutex);

	return ret;
}

3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190
/* Call module constructors. */
static void do_mod_ctors(struct module *mod)
{
#ifdef CONFIG_CONSTRUCTORS
	unsigned long i;

	for (i = 0; i < mod->num_ctors; i++)
		mod->ctors[i]();
#endif
}

3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203
/* For freeing module_init on success, in case kallsyms traversing */
struct mod_initfree {
	struct rcu_head rcu;
	void *module_init;
};

static void do_free_init(struct rcu_head *head)
{
	struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
	module_memfree(m->module_init);
	kfree(m);
}

3204 3205 3206 3207 3208 3209 3210
/*
 * This is where the real work happens.
 *
 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
 * helper command 'lx-symbols'.
 */
static noinline int do_init_module(struct module *mod)
3211 3212
{
	int ret = 0;
3213 3214 3215 3216 3217 3218 3219 3220
	struct mod_initfree *freeinit;

	freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
	if (!freeinit) {
		ret = -ENOMEM;
		goto fail;
	}
	freeinit->module_init = mod->module_init;
3221

3222 3223 3224 3225 3226 3227
	/*
	 * We want to find out whether @mod uses async during init.  Clear
	 * PF_USED_ASYNC.  async_schedule*() will set it.
	 */
	current->flags &= ~PF_USED_ASYNC;

3228 3229 3230 3231 3232
	do_mod_ctors(mod);
	/* Start the module */
	if (mod->init != NULL)
		ret = do_one_initcall(mod->init);
	if (ret < 0) {
3233
		goto fail_free_freeinit;
3234 3235
	}
	if (ret > 0) {
3236 3237 3238 3239
		pr_warn("%s: '%s'->init suspiciously returned %d, it should "
			"follow 0/-E convention\n"
			"%s: loading module anyway...\n",
			__func__, mod->name, ret, __func__);
3240 3241 3242 3243 3244 3245 3246 3247
		dump_stack();
	}

	/* Now it's a first class citizen! */
	mod->state = MODULE_STATE_LIVE;
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_LIVE, mod);

3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264
	/*
	 * We need to finish all async code before the module init sequence
	 * is done.  This has potential to deadlock.  For example, a newly
	 * detected block device can trigger request_module() of the
	 * default iosched from async probing task.  Once userland helper
	 * reaches here, async_synchronize_full() will wait on the async
	 * task waiting on request_module() and deadlock.
	 *
	 * This deadlock is avoided by perfomring async_synchronize_full()
	 * iff module init queued any async jobs.  This isn't a full
	 * solution as it will deadlock the same if module loading from
	 * async jobs nests more than once; however, due to the various
	 * constraints, this hack seems to be the best option for now.
	 * Please refer to the following thread for details.
	 *
	 * http://thread.gmane.org/gmane.linux.kernel/1420814
	 */
3265
	if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3266
		async_synchronize_full();
3267 3268 3269 3270 3271 3272 3273 3274 3275 3276

	mutex_lock(&module_mutex);
	/* Drop initial reference. */
	module_put(mod);
	trim_init_extable(mod);
#ifdef CONFIG_KALLSYMS
	mod->num_symtab = mod->core_num_syms;
	mod->symtab = mod->core_symtab;
	mod->strtab = mod->core_strtab;
#endif
3277
	mod_tree_remove_init(mod);
3278
	unset_module_init_ro_nx(mod);
3279
	module_arch_freeing_init(mod);
3280 3281 3282 3283
	mod->module_init = NULL;
	mod->init_size = 0;
	mod->init_ro_size = 0;
	mod->init_text_size = 0;
3284 3285
	/*
	 * We want to free module_init, but be aware that kallsyms may be
3286 3287 3288
	 * walking this with preempt disabled.  In all the failure paths, we
	 * call synchronize_sched(), but we don't want to slow down the success
	 * path, so use actual RCU here.
3289
	 */
3290
	call_rcu_sched(&freeinit->rcu, do_free_init);
3291 3292 3293 3294
	mutex_unlock(&module_mutex);
	wake_up_all(&module_wq);

	return 0;
3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307

fail_free_freeinit:
	kfree(freeinit);
fail:
	/* Try to protect us from buggy refcounters. */
	mod->state = MODULE_STATE_GOING;
	synchronize_sched();
	module_put(mod);
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
	free_module(mod);
	wake_up_all(&module_wq);
	return ret;
3308 3309 3310 3311 3312 3313 3314 3315 3316 3317
}

static int may_init_module(void)
{
	if (!capable(CAP_SYS_MODULE) || modules_disabled)
		return -EPERM;

	return 0;
}

3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331
/*
 * We try to place it in the list now to make sure it's unique before
 * we dedicate too many resources.  In particular, temporary percpu
 * memory exhaustion.
 */
static int add_unformed_module(struct module *mod)
{
	int err;
	struct module *old;

	mod->state = MODULE_STATE_UNFORMED;

again:
	mutex_lock(&module_mutex);
3332 3333
	old = find_module_all(mod->name, strlen(mod->name), true);
	if (old != NULL) {
3334 3335 3336 3337
		if (old->state == MODULE_STATE_COMING
		    || old->state == MODULE_STATE_UNFORMED) {
			/* Wait in case it fails to load. */
			mutex_unlock(&module_mutex);
3338 3339
			err = wait_event_interruptible(module_wq,
					       finished_loading(mod->name));
3340 3341 3342 3343 3344 3345 3346
			if (err)
				goto out_unlocked;
			goto again;
		}
		err = -EEXIST;
		goto out;
	}
3347
	mod_update_bounds(mod);
3348
	list_add_rcu(&mod->list, &modules);
3349
	mod_tree_insert(mod);
3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371
	err = 0;

out:
	mutex_unlock(&module_mutex);
out_unlocked:
	return err;
}

static int complete_formation(struct module *mod, struct load_info *info)
{
	int err;

	mutex_lock(&module_mutex);

	/* Find duplicate symbols (must be called under lock). */
	err = verify_export_symbols(mod);
	if (err < 0)
		goto out;

	/* This relies on module_mutex for list integrity. */
	module_bug_finalize(info->hdr, info->sechdrs, mod);

3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383
	/* Set RO and NX regions for core */
	set_section_ro_nx(mod->module_core,
				mod->core_text_size,
				mod->core_ro_size,
				mod->core_size);

	/* Set RO and NX regions for init */
	set_section_ro_nx(mod->module_init,
				mod->init_text_size,
				mod->init_ro_size,
				mod->init_size);

3384 3385 3386
	/* Mark state as coming so strong_try_module_get() ignores us,
	 * but kallsyms etc. can see us. */
	mod->state = MODULE_STATE_COMING;
3387 3388 3389 3390 3391
	mutex_unlock(&module_mutex);

	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_COMING, mod);
	return 0;
3392 3393 3394 3395 3396 3397

out:
	mutex_unlock(&module_mutex);
	return err;
}

3398 3399
static int unknown_module_param_cb(char *param, char *val, const char *modname,
				   void *arg)
3400
{
3401 3402 3403 3404 3405 3406 3407 3408
	struct module *mod = arg;
	int ret;

	if (strcmp(param, "async_probe") == 0) {
		mod->async_probe_requested = true;
		return 0;
	}

3409
	/* Check for magic 'dyndbg' arg */
3410
	ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3411 3412
	if (ret != 0)
		pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3413 3414 3415
	return 0;
}

3416 3417
/* Allocate and load the module: note that size of section 0 is always
   zero, and we rely on this for optional sections. */
3418 3419
static int load_module(struct load_info *info, const char __user *uargs,
		       int flags)
3420
{
3421
	struct module *mod;
3422
	long err;
3423
	char *after_dashes;
3424

3425 3426 3427
	err = module_sig_check(info);
	if (err)
		goto free_copy;
3428

3429
	err = elf_header_check(info);
3430
	if (err)
3431
		goto free_copy;
3432 3433

	/* Figure out module layout, and allocate all the memory. */
3434
	mod = layout_and_allocate(info, flags);
3435 3436
	if (IS_ERR(mod)) {
		err = PTR_ERR(mod);
3437
		goto free_copy;
L
Linus Torvalds 已提交
3438 3439
	}

3440 3441 3442
	/* Reserve our place in the list. */
	err = add_unformed_module(mod);
	if (err)
3443 3444
		goto free_module;

3445
#ifdef CONFIG_MODULE_SIG
3446
	mod->sig_ok = info->sig_ok;
3447
	if (!mod->sig_ok) {
3448
		pr_notice_once("%s: module verification failed: signature "
3449
			       "and/or required key missing - tainting "
3450
			       "kernel\n", mod->name);
3451
		add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3452
	}
3453 3454
#endif

3455
	/* To avoid stressing percpu allocator, do this once we're unique. */
3456
	err = percpu_modalloc(mod, info);
3457 3458 3459
	if (err)
		goto unlink_mod;

3460
	/* Now module is in final location, initialize linked lists, etc. */
3461 3462
	err = module_unload_init(mod);
	if (err)
3463
		goto unlink_mod;
L
Linus Torvalds 已提交
3464

3465
	init_param_lock(mod);
3466

3467 3468
	/* Now we've got everything in the final locations, we can
	 * find optional sections. */
3469 3470 3471
	err = find_module_sections(mod, info);
	if (err)
		goto free_unload;
3472

3473
	err = check_module_license_and_versions(mod);
3474 3475
	if (err)
		goto free_unload;
3476

3477
	/* Set up MODINFO_ATTR fields */
3478
	setup_modinfo(mod, info);
3479

L
Linus Torvalds 已提交
3480
	/* Fix up syms, so that st_value is a pointer to location. */
3481
	err = simplify_symbols(mod, info);
L
Linus Torvalds 已提交
3482
	if (err < 0)
3483
		goto free_modinfo;
L
Linus Torvalds 已提交
3484

3485
	err = apply_relocations(mod, info);
3486
	if (err < 0)
3487
		goto free_modinfo;
L
Linus Torvalds 已提交
3488

3489
	err = post_relocation(mod, info);
L
Linus Torvalds 已提交
3490
	if (err < 0)
3491
		goto free_modinfo;
L
Linus Torvalds 已提交
3492

3493
	flush_module_icache(mod);
3494

3495 3496 3497 3498 3499 3500
	/* Now copy in args */
	mod->args = strndup_user(uargs, ~0UL >> 1);
	if (IS_ERR(mod->args)) {
		err = PTR_ERR(mod->args);
		goto free_arch_cleanup;
	}
3501

3502
	dynamic_debug_setup(info->debug, info->num_debug);
3503

3504 3505 3506
	/* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
	ftrace_module_init(mod);

3507 3508 3509
	/* Finally it's fully formed, ready to start executing. */
	err = complete_formation(mod, info);
	if (err)
3510
		goto ddebug_cleanup;
3511

3512
	/* Module is ready to execute: parsing args may do that. */
3513
	after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3514 3515
				  -32768, 32767, NULL,
				  unknown_module_param_cb);
3516 3517
	if (IS_ERR(after_dashes)) {
		err = PTR_ERR(after_dashes);
3518
		goto bug_cleanup;
3519 3520 3521 3522
	} else if (after_dashes) {
		pr_warn("%s: parameters '%s' after `--' ignored\n",
		       mod->name, after_dashes);
	}
L
Linus Torvalds 已提交
3523

3524
	/* Link in to syfs. */
3525
	err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
L
Linus Torvalds 已提交
3526
	if (err < 0)
3527
		goto bug_cleanup;
3528

3529
	/* Get rid of temporary copy. */
3530
	free_copy(info);
L
Linus Torvalds 已提交
3531 3532

	/* Done! */
3533
	trace_module_load(mod);
3534 3535

	return do_init_module(mod);
L
Linus Torvalds 已提交
3536

3537 3538
 bug_cleanup:
	/* module_bug_cleanup needs module_mutex protection */
3539
	mutex_lock(&module_mutex);
3540
	module_bug_cleanup(mod);
3541
	mutex_unlock(&module_mutex);
3542

3543 3544 3545
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);

3546 3547 3548 3549
	/* we can't deallocate the module until we clear memory protection */
	unset_module_init_ro_nx(mod);
	unset_module_core_ro_nx(mod);

3550
 ddebug_cleanup:
3551
	dynamic_debug_remove(info->debug);
3552
	synchronize_sched();
3553 3554
	kfree(mod->args);
 free_arch_cleanup:
L
Linus Torvalds 已提交
3555
	module_arch_cleanup(mod);
3556
 free_modinfo:
3557
	free_modinfo(mod);
3558
 free_unload:
L
Linus Torvalds 已提交
3559
	module_unload_free(mod);
3560 3561 3562 3563
 unlink_mod:
	mutex_lock(&module_mutex);
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
3564
	mod_tree_remove(mod);
3565
	wake_up_all(&module_wq);
3566 3567
	/* Wait for RCU-sched synchronizing before releasing mod->list. */
	synchronize_sched();
3568
	mutex_unlock(&module_mutex);
3569
 free_module:
3570 3571 3572
	/* Free lock-classes; relies on the preceding sync_rcu() */
	lockdep_free_key_range(mod->module_core, mod->core_size);

3573
	module_deallocate(mod, info);
3574
 free_copy:
3575 3576
	free_copy(info);
	return err;
3577 3578
}

3579 3580
SYSCALL_DEFINE3(init_module, void __user *, umod,
		unsigned long, len, const char __user *, uargs)
L
Linus Torvalds 已提交
3581
{
3582 3583
	int err;
	struct load_info info = { };
L
Linus Torvalds 已提交
3584

3585 3586 3587
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3588

3589 3590
	pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
	       umod, len, uargs);
L
Linus Torvalds 已提交
3591

3592 3593 3594
	err = copy_module_from_user(umod, len, &info);
	if (err)
		return err;
L
Linus Torvalds 已提交
3595

3596
	return load_module(&info, uargs, 0);
3597
}
3598

3599
SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3600 3601 3602
{
	int err;
	struct load_info info = { };
3603

3604 3605 3606
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3607

3608
	pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3609

3610 3611 3612
	if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
		      |MODULE_INIT_IGNORE_VERMAGIC))
		return -EINVAL;
3613

3614 3615 3616
	err = copy_module_from_fd(fd, &info);
	if (err)
		return err;
L
Linus Torvalds 已提交
3617

3618
	return load_module(&info, uargs, flags);
L
Linus Torvalds 已提交
3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632
}

static inline int within(unsigned long addr, void *start, unsigned long size)
{
	return ((void *)addr >= start && (void *)addr < start + size);
}

#ifdef CONFIG_KALLSYMS
/*
 * This ignores the intensely annoying "mapping symbols" found
 * in ARM ELF files: $a, $t and $d.
 */
static inline int is_arm_mapping_symbol(const char *str)
{
3633 3634
	if (str[0] == '.' && str[1] == 'L')
		return true;
3635
	return str[0] == '$' && strchr("axtd", str[1])
L
Linus Torvalds 已提交
3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647
	       && (str[2] == '\0' || str[2] == '.');
}

static const char *get_ksymbol(struct module *mod,
			       unsigned long addr,
			       unsigned long *size,
			       unsigned long *offset)
{
	unsigned int i, best = 0;
	unsigned long nextval;

	/* At worse, next value is at end of module */
3648
	if (within_module_init(addr, mod))
L
Linus Torvalds 已提交
3649
		nextval = (unsigned long)mod->module_init+mod->init_text_size;
3650
	else
L
Linus Torvalds 已提交
3651 3652
		nextval = (unsigned long)mod->module_core+mod->core_text_size;

L
Lucas De Marchi 已提交
3653
	/* Scan for closest preceding symbol, and next symbol. (ELF
3654
	   starts real symbols at 1). */
L
Linus Torvalds 已提交
3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675
	for (i = 1; i < mod->num_symtab; i++) {
		if (mod->symtab[i].st_shndx == SHN_UNDEF)
			continue;

		/* We ignore unnamed symbols: they're uninformative
		 * and inserted at a whim. */
		if (mod->symtab[i].st_value <= addr
		    && mod->symtab[i].st_value > mod->symtab[best].st_value
		    && *(mod->strtab + mod->symtab[i].st_name) != '\0'
		    && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
			best = i;
		if (mod->symtab[i].st_value > addr
		    && mod->symtab[i].st_value < nextval
		    && *(mod->strtab + mod->symtab[i].st_name) != '\0'
		    && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
			nextval = mod->symtab[i].st_value;
	}

	if (!best)
		return NULL;

3676 3677 3678 3679
	if (size)
		*size = nextval - mod->symtab[best].st_value;
	if (offset)
		*offset = addr - mod->symtab[best].st_value;
L
Linus Torvalds 已提交
3680 3681 3682
	return mod->strtab + mod->symtab[best].st_name;
}

3683 3684
/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3685
const char *module_address_lookup(unsigned long addr,
3686 3687 3688 3689
			    unsigned long *size,
			    unsigned long *offset,
			    char **modname,
			    char *namebuf)
L
Linus Torvalds 已提交
3690
{
3691
	const char *ret = NULL;
3692
	struct module *mod;
L
Linus Torvalds 已提交
3693

3694
	preempt_disable();
3695 3696 3697 3698 3699
	mod = __module_address(addr);
	if (mod) {
		if (modname)
			*modname = mod->name;
		ret = get_ksymbol(mod, addr, size, offset);
L
Linus Torvalds 已提交
3700
	}
3701 3702 3703 3704 3705
	/* Make a copy in here where it's safe */
	if (ret) {
		strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
		ret = namebuf;
	}
3706
	preempt_enable();
3707

3708
	return ret;
L
Linus Torvalds 已提交
3709 3710
}

3711 3712 3713 3714
int lookup_module_symbol_name(unsigned long addr, char *symname)
{
	struct module *mod;

3715
	preempt_disable();
3716
	list_for_each_entry_rcu(mod, &modules, list) {
3717 3718
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3719
		if (within_module(addr, mod)) {
3720 3721 3722 3723 3724
			const char *sym;

			sym = get_ksymbol(mod, addr, NULL, NULL);
			if (!sym)
				goto out;
3725
			strlcpy(symname, sym, KSYM_NAME_LEN);
3726
			preempt_enable();
3727 3728 3729 3730
			return 0;
		}
	}
out:
3731
	preempt_enable();
3732 3733 3734
	return -ERANGE;
}

3735 3736 3737 3738 3739
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
			unsigned long *offset, char *modname, char *name)
{
	struct module *mod;

3740
	preempt_disable();
3741
	list_for_each_entry_rcu(mod, &modules, list) {
3742 3743
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3744
		if (within_module(addr, mod)) {
3745 3746 3747 3748 3749 3750
			const char *sym;

			sym = get_ksymbol(mod, addr, size, offset);
			if (!sym)
				goto out;
			if (modname)
3751
				strlcpy(modname, mod->name, MODULE_NAME_LEN);
3752
			if (name)
3753
				strlcpy(name, sym, KSYM_NAME_LEN);
3754
			preempt_enable();
3755 3756 3757 3758
			return 0;
		}
	}
out:
3759
	preempt_enable();
3760 3761 3762
	return -ERANGE;
}

3763 3764
int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
			char *name, char *module_name, int *exported)
L
Linus Torvalds 已提交
3765 3766 3767
{
	struct module *mod;

3768
	preempt_disable();
3769
	list_for_each_entry_rcu(mod, &modules, list) {
3770 3771
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
L
Linus Torvalds 已提交
3772 3773 3774
		if (symnum < mod->num_symtab) {
			*value = mod->symtab[symnum].st_value;
			*type = mod->symtab[symnum].st_info;
3775
			strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3776 3777
				KSYM_NAME_LEN);
			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3778
			*exported = is_exported(name, *value, mod);
3779
			preempt_enable();
3780
			return 0;
L
Linus Torvalds 已提交
3781 3782 3783
		}
		symnum -= mod->num_symtab;
	}
3784
	preempt_enable();
3785
	return -ERANGE;
L
Linus Torvalds 已提交
3786 3787 3788 3789 3790 3791 3792
}

static unsigned long mod_find_symname(struct module *mod, const char *name)
{
	unsigned int i;

	for (i = 0; i < mod->num_symtab; i++)
3793 3794
		if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
		    mod->symtab[i].st_info != 'U')
L
Linus Torvalds 已提交
3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806
			return mod->symtab[i].st_value;
	return 0;
}

/* Look for this name: can be of form module:name. */
unsigned long module_kallsyms_lookup_name(const char *name)
{
	struct module *mod;
	char *colon;
	unsigned long ret = 0;

	/* Don't lock: we're in enough trouble already. */
3807
	preempt_disable();
L
Linus Torvalds 已提交
3808
	if ((colon = strchr(name, ':')) != NULL) {
3809
		if ((mod = find_module_all(name, colon - name, false)) != NULL)
L
Linus Torvalds 已提交
3810 3811
			ret = mod_find_symname(mod, colon+1);
	} else {
3812 3813 3814
		list_for_each_entry_rcu(mod, &modules, list) {
			if (mod->state == MODULE_STATE_UNFORMED)
				continue;
L
Linus Torvalds 已提交
3815 3816
			if ((ret = mod_find_symname(mod, name)) != 0)
				break;
3817
		}
L
Linus Torvalds 已提交
3818
	}
3819
	preempt_enable();
L
Linus Torvalds 已提交
3820 3821
	return ret;
}
3822 3823 3824 3825 3826 3827 3828 3829 3830

int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
					     struct module *, unsigned long),
				   void *data)
{
	struct module *mod;
	unsigned int i;
	int ret;

3831 3832
	module_assert_mutex();

3833
	list_for_each_entry(mod, &modules, list) {
3834 3835
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3836 3837 3838 3839 3840 3841 3842 3843 3844
		for (i = 0; i < mod->num_symtab; i++) {
			ret = fn(data, mod->strtab + mod->symtab[i].st_name,
				 mod, mod->symtab[i].st_value);
			if (ret != 0)
				return ret;
		}
	}
	return 0;
}
L
Linus Torvalds 已提交
3845 3846
#endif /* CONFIG_KALLSYMS */

3847
static char *module_flags(struct module *mod, char *buf)
3848 3849 3850
{
	int bx = 0;

3851
	BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3852 3853 3854
	if (mod->taints ||
	    mod->state == MODULE_STATE_GOING ||
	    mod->state == MODULE_STATE_COMING) {
3855
		buf[bx++] = '(';
3856
		bx += module_flags_taint(mod, buf + bx);
3857 3858 3859 3860 3861 3862
		/* Show a - for module-is-being-unloaded */
		if (mod->state == MODULE_STATE_GOING)
			buf[bx++] = '-';
		/* Show a + for module-is-being-loaded */
		if (mod->state == MODULE_STATE_COMING)
			buf[bx++] = '+';
3863 3864 3865 3866 3867 3868 3869
		buf[bx++] = ')';
	}
	buf[bx] = '\0';

	return buf;
}

3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884 3885 3886 3887
#ifdef CONFIG_PROC_FS
/* Called by the /proc file system to return a list of modules. */
static void *m_start(struct seq_file *m, loff_t *pos)
{
	mutex_lock(&module_mutex);
	return seq_list_start(&modules, *pos);
}

static void *m_next(struct seq_file *m, void *p, loff_t *pos)
{
	return seq_list_next(p, &modules, pos);
}

static void m_stop(struct seq_file *m, void *p)
{
	mutex_unlock(&module_mutex);
}

L
Linus Torvalds 已提交
3888 3889 3890
static int m_show(struct seq_file *m, void *p)
{
	struct module *mod = list_entry(p, struct module, list);
3891 3892
	char buf[8];

3893 3894 3895 3896
	/* We always ignore unformed modules. */
	if (mod->state == MODULE_STATE_UNFORMED)
		return 0;

3897
	seq_printf(m, "%s %u",
L
Linus Torvalds 已提交
3898 3899 3900 3901 3902
		   mod->name, mod->init_size + mod->core_size);
	print_unload_info(m, mod);

	/* Informative for users. */
	seq_printf(m, " %s",
3903 3904
		   mod->state == MODULE_STATE_GOING ? "Unloading" :
		   mod->state == MODULE_STATE_COMING ? "Loading" :
L
Linus Torvalds 已提交
3905 3906
		   "Live");
	/* Used by oprofile and other similar tools. */
3907
	seq_printf(m, " 0x%pK", mod->module_core);
L
Linus Torvalds 已提交
3908

3909 3910
	/* Taints info */
	if (mod->taints)
3911
		seq_printf(m, " %s", module_flags(mod, buf));
3912

3913
	seq_puts(m, "\n");
L
Linus Torvalds 已提交
3914 3915 3916 3917 3918 3919 3920 3921
	return 0;
}

/* Format: modulename size refcount deps address

   Where refcount is a number or -, and deps is a comma-separated list
   of depends or -.
*/
3922
static const struct seq_operations modules_op = {
L
Linus Torvalds 已提交
3923 3924 3925 3926 3927 3928
	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= m_show
};

3929 3930 3931 3932 3933 3934 3935 3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947 3948
static int modules_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &modules_op);
}

static const struct file_operations proc_modules_operations = {
	.open		= modules_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

static int __init proc_modules_init(void)
{
	proc_create("modules", 0, NULL, &proc_modules_operations);
	return 0;
}
module_init(proc_modules_init);
#endif

L
Linus Torvalds 已提交
3949 3950 3951 3952 3953 3954
/* Given an address, look for it in the module exception tables. */
const struct exception_table_entry *search_module_extables(unsigned long addr)
{
	const struct exception_table_entry *e = NULL;
	struct module *mod;

3955
	preempt_disable();
3956
	list_for_each_entry_rcu(mod, &modules, list) {
3957 3958
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
L
Linus Torvalds 已提交
3959 3960
		if (mod->num_exentries == 0)
			continue;
3961

L
Linus Torvalds 已提交
3962 3963 3964 3965 3966 3967
		e = search_extable(mod->extable,
				   mod->extable + mod->num_exentries - 1,
				   addr);
		if (e)
			break;
	}
3968
	preempt_enable();
L
Linus Torvalds 已提交
3969 3970

	/* Now, if we found one, we are running inside it now, hence
3971
	   we cannot unload the module, hence no refcnt needed. */
L
Linus Torvalds 已提交
3972 3973 3974
	return e;
}

3975
/*
R
Rusty Russell 已提交
3976 3977 3978 3979 3980
 * is_module_address - is this address inside a module?
 * @addr: the address to check.
 *
 * See is_module_text_address() if you simply want to see if the address
 * is code (not data).
3981
 */
R
Rusty Russell 已提交
3982
bool is_module_address(unsigned long addr)
3983
{
R
Rusty Russell 已提交
3984
	bool ret;
3985

3986
	preempt_disable();
R
Rusty Russell 已提交
3987
	ret = __module_address(addr) != NULL;
3988
	preempt_enable();
3989

R
Rusty Russell 已提交
3990
	return ret;
3991 3992
}

R
Rusty Russell 已提交
3993 3994 3995 3996 3997 3998 3999
/*
 * __module_address - get the module which contains an address.
 * @addr: the address.
 *
 * Must be called with preempt disabled or module mutex held so that
 * module doesn't get freed during this.
 */
4000
struct module *__module_address(unsigned long addr)
L
Linus Torvalds 已提交
4001 4002 4003
{
	struct module *mod;

4004 4005 4006
	if (addr < module_addr_min || addr > module_addr_max)
		return NULL;

4007 4008
	module_assert_mutex_or_preempt();

4009
	mod = mod_find(addr);
4010 4011
	if (mod) {
		BUG_ON(!within_module(addr, mod));
4012
		if (mod->state == MODULE_STATE_UNFORMED)
4013
			mod = NULL;
4014
	}
4015
	return mod;
L
Linus Torvalds 已提交
4016
}
4017
EXPORT_SYMBOL_GPL(__module_address);
L
Linus Torvalds 已提交
4018

R
Rusty Russell 已提交
4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054 4055
/*
 * is_module_text_address - is this address inside module code?
 * @addr: the address to check.
 *
 * See is_module_address() if you simply want to see if the address is
 * anywhere in a module.  See kernel_text_address() for testing if an
 * address corresponds to kernel or module code.
 */
bool is_module_text_address(unsigned long addr)
{
	bool ret;

	preempt_disable();
	ret = __module_text_address(addr) != NULL;
	preempt_enable();

	return ret;
}

/*
 * __module_text_address - get the module whose code contains an address.
 * @addr: the address.
 *
 * Must be called with preempt disabled or module mutex held so that
 * module doesn't get freed during this.
 */
struct module *__module_text_address(unsigned long addr)
{
	struct module *mod = __module_address(addr);
	if (mod) {
		/* Make sure it's within the text section. */
		if (!within(addr, mod->module_init, mod->init_text_size)
		    && !within(addr, mod->module_core, mod->core_text_size))
			mod = NULL;
	}
	return mod;
}
4056
EXPORT_SYMBOL_GPL(__module_text_address);
R
Rusty Russell 已提交
4057

L
Linus Torvalds 已提交
4058 4059 4060 4061
/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
	struct module *mod;
4062
	char buf[8];
L
Linus Torvalds 已提交
4063

4064
	printk(KERN_DEFAULT "Modules linked in:");
4065 4066
	/* Most callers should already have preempt disabled, but make sure */
	preempt_disable();
4067 4068 4069
	list_for_each_entry_rcu(mod, &modules, list) {
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
J
Jiri Slaby 已提交
4070
		pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4071
	}
4072
	preempt_enable();
4073
	if (last_unloaded_module[0])
J
Jiri Slaby 已提交
4074 4075
		pr_cont(" [last unloaded: %s]", last_unloaded_module);
	pr_cont("\n");
L
Linus Torvalds 已提交
4076 4077 4078
}

#ifdef CONFIG_MODVERSIONS
4079 4080 4081 4082 4083 4084
/* Generate the signature for all relevant module structures here.
 * If these change, we don't want to try to parse the module. */
void module_layout(struct module *mod,
		   struct modversion_info *ver,
		   struct kernel_param *kp,
		   struct kernel_symbol *ks,
4085
		   struct tracepoint * const *tp)
4086 4087 4088
{
}
EXPORT_SYMBOL(module_layout);
L
Linus Torvalds 已提交
4089
#endif
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