module.c 102.9 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

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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.
 *
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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 module_layout *layout = container_of(n, struct module_layout, mtn.node);
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	return (unsigned long)layout->base;
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}

static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
{
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	struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
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	return (unsigned long)layout->size;
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}

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)
{
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	mod->core_layout.mtn.mod = mod;
	mod->init_layout.mtn.mod = mod;
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	__mod_tree_insert(&mod->core_layout.mtn);
	if (mod->init_layout.size)
		__mod_tree_insert(&mod->init_layout.mtn);
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}

static void mod_tree_remove_init(struct module *mod)
{
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	if (mod->init_layout.size)
		__mod_tree_remove(&mod->init_layout.mtn);
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}

static void mod_tree_remove(struct module *mod)
{
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	__mod_tree_remove(&mod->core_layout.mtn);
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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)
{
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	__mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
	if (mod->init_layout.size)
		__mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
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}

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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;
595
		if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
L
Linus Torvalds 已提交
596 597 598 599
			return mod;
	}
	return NULL;
}
600 601 602

struct module *find_module(const char *name)
{
603
	module_assert_mutex();
604
	return find_module_all(name, strlen(name), false);
605
}
606
EXPORT_SYMBOL_GPL(find_module);
L
Linus Torvalds 已提交
607 608

#ifdef CONFIG_SMP
609

610
static inline void __percpu *mod_percpu(struct module *mod)
611
{
612 613
	return mod->percpu;
}
614

R
Rusty Russell 已提交
615
static int percpu_modalloc(struct module *mod, struct load_info *info)
616
{
R
Rusty Russell 已提交
617 618 619 620 621 622
	Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
	unsigned long align = pcpusec->sh_addralign;

	if (!pcpusec->sh_size)
		return 0;

623
	if (align > PAGE_SIZE) {
A
Andrew Morton 已提交
624 625
		pr_warn("%s: per-cpu alignment %li > %li\n",
			mod->name, align, PAGE_SIZE);
626 627 628
		align = PAGE_SIZE;
	}

R
Rusty Russell 已提交
629
	mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
630
	if (!mod->percpu) {
A
Andrew Morton 已提交
631 632
		pr_warn("%s: Could not allocate %lu bytes percpu data\n",
			mod->name, (unsigned long)pcpusec->sh_size);
633 634
		return -ENOMEM;
	}
R
Rusty Russell 已提交
635
	mod->percpu_size = pcpusec->sh_size;
636
	return 0;
637 638
}

639
static void percpu_modfree(struct module *mod)
640
{
641
	free_percpu(mod->percpu);
642 643
}

644
static unsigned int find_pcpusec(struct load_info *info)
645
{
646
	return find_sec(info, ".data..percpu");
647 648
}

649 650
static void percpu_modcopy(struct module *mod,
			   const void *from, unsigned long size)
651 652 653 654
{
	int cpu;

	for_each_possible_cpu(cpu)
655
		memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
656 657
}

658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674
/**
 * 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) {
675 676
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
677 678 679 680 681 682 683 684 685 686 687 688 689 690 691
		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;
692 693
}

L
Linus Torvalds 已提交
694
#else /* ... !CONFIG_SMP */
695

696
static inline void __percpu *mod_percpu(struct module *mod)
L
Linus Torvalds 已提交
697 698 699
{
	return NULL;
}
R
Rusty Russell 已提交
700
static int percpu_modalloc(struct module *mod, struct load_info *info)
701
{
R
Rusty Russell 已提交
702 703 704 705
	/* 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;
706 707
}
static inline void percpu_modfree(struct module *mod)
L
Linus Torvalds 已提交
708 709
{
}
710
static unsigned int find_pcpusec(struct load_info *info)
L
Linus Torvalds 已提交
711 712 713
{
	return 0;
}
714 715
static inline void percpu_modcopy(struct module *mod,
				  const void *from, unsigned long size)
L
Linus Torvalds 已提交
716 717 718 719
{
	/* pcpusec should be 0, and size of that section should be 0. */
	BUG_ON(size != 0);
}
720 721 722 723
bool is_module_percpu_address(unsigned long addr)
{
	return false;
}
724

L
Linus Torvalds 已提交
725 726
#endif /* CONFIG_SMP */

727 728 729 730 731 732
#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,   \
733
			struct module_kobject *mk, char *buffer)      \
734
{                                                                     \
735
	return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field);  \
736 737 738 739 740 741 742
}                                                                     \
static int modinfo_##field##_exists(struct module *mod)               \
{                                                                     \
	return mod->field != NULL;                                    \
}                                                                     \
static void free_modinfo_##field(struct module *mod)                  \
{                                                                     \
D
Daniel Walker 已提交
743 744
	kfree(mod->field);                                            \
	mod->field = NULL;                                            \
745 746
}                                                                     \
static struct module_attribute modinfo_##field = {                    \
747
	.attr = { .name = __stringify(field), .mode = 0444 },         \
748 749 750 751 752 753 754 755 756
	.show = show_modinfo_##field,                                 \
	.setup = setup_modinfo_##field,                               \
	.test = modinfo_##field##_exists,                             \
	.free = free_modinfo_##field,                                 \
};

MODINFO_ATTR(version);
MODINFO_ATTR(srcversion);

757 758
static char last_unloaded_module[MODULE_NAME_LEN+1];

759
#ifdef CONFIG_MODULE_UNLOAD
760 761 762

EXPORT_TRACEPOINT_SYMBOL(module_get);

763 764 765
/* MODULE_REF_BASE is the base reference count by kmodule loader. */
#define MODULE_REF_BASE	1

L
Linus Torvalds 已提交
766
/* Init the unload section of the module. */
767
static int module_unload_init(struct module *mod)
L
Linus Torvalds 已提交
768
{
769 770 771 772 773
	/*
	 * Initialize reference counter to MODULE_REF_BASE.
	 * refcnt == 0 means module is going.
	 */
	atomic_set(&mod->refcnt, MODULE_REF_BASE);
774

775 776
	INIT_LIST_HEAD(&mod->source_list);
	INIT_LIST_HEAD(&mod->target_list);
777

L
Linus Torvalds 已提交
778
	/* Hold reference count during initialization. */
779
	atomic_inc(&mod->refcnt);
780 781

	return 0;
L
Linus Torvalds 已提交
782 783 784 785 786 787 788
}

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

789 790
	list_for_each_entry(use, &b->source_list, source_list) {
		if (use->source == a) {
791
			pr_debug("%s uses %s!\n", a->name, b->name);
L
Linus Torvalds 已提交
792 793 794
			return 1;
		}
	}
795
	pr_debug("%s does not use %s!\n", a->name, b->name);
L
Linus Torvalds 已提交
796 797 798
	return 0;
}

799 800 801 802 803 804 805 806 807 808 809
/*
 * 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;

810
	pr_debug("Allocating new usage for %s.\n", a->name);
811 812
	use = kmalloc(sizeof(*use), GFP_ATOMIC);
	if (!use) {
A
Andrew Morton 已提交
813
		pr_warn("%s: out of memory loading\n", a->name);
814 815 816 817 818 819 820 821 822 823
		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;
}

824
/* Module a uses b: caller needs module_mutex() */
825
int ref_module(struct module *a, struct module *b)
L
Linus Torvalds 已提交
826
{
827
	int err;
K
Kay Sievers 已提交
828

829
	if (b == NULL || already_uses(a, b))
830 831
		return 0;

832 833
	/* If module isn't available, we fail. */
	err = strong_try_module_get(b);
834
	if (err)
835
		return err;
L
Linus Torvalds 已提交
836

837 838
	err = add_module_usage(a, b);
	if (err) {
L
Linus Torvalds 已提交
839
		module_put(b);
840
		return err;
L
Linus Torvalds 已提交
841
	}
842
	return 0;
L
Linus Torvalds 已提交
843
}
844
EXPORT_SYMBOL_GPL(ref_module);
L
Linus Torvalds 已提交
845 846 847 848

/* Clear the unload stuff of the module. */
static void module_unload_free(struct module *mod)
{
849
	struct module_use *use, *tmp;
L
Linus Torvalds 已提交
850

851
	mutex_lock(&module_mutex);
852 853
	list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
		struct module *i = use->target;
854
		pr_debug("%s unusing %s\n", mod->name, i->name);
855 856 857 858
		module_put(i);
		list_del(&use->source_list);
		list_del(&use->target_list);
		kfree(use);
L
Linus Torvalds 已提交
859
	}
860
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
861 862 863
}

#ifdef CONFIG_MODULE_FORCE_UNLOAD
864
static inline int try_force_unload(unsigned int flags)
L
Linus Torvalds 已提交
865 866 867
{
	int ret = (flags & O_TRUNC);
	if (ret)
868
		add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
L
Linus Torvalds 已提交
869 870 871
	return ret;
}
#else
872
static inline int try_force_unload(unsigned int flags)
L
Linus Torvalds 已提交
873 874 875 876 877
{
	return 0;
}
#endif /* CONFIG_MODULE_FORCE_UNLOAD */

878 879
/* Try to release refcount of module, 0 means success. */
static int try_release_module_ref(struct module *mod)
L
Linus Torvalds 已提交
880
{
881
	int ret;
L
Linus Torvalds 已提交
882

883 884 885 886 887 888
	/* 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
889

890 891
	return ret;
}
L
Linus Torvalds 已提交
892

893 894
static int try_stop_module(struct module *mod, int flags, int *forced)
{
895
	/* If it's not unused, quit unless we're forcing. */
896 897 898
	if (try_release_module_ref(mod) != 0) {
		*forced = try_force_unload(flags);
		if (!(*forced))
L
Linus Torvalds 已提交
899 900 901 902
			return -EWOULDBLOCK;
	}

	/* Mark it as dying. */
903
	mod->state = MODULE_STATE_GOING;
L
Linus Torvalds 已提交
904

905
	return 0;
L
Linus Torvalds 已提交
906 907
}

908 909 910 911 912 913 914 915 916 917
/**
 * 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
918
{
919
	return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
L
Linus Torvalds 已提交
920 921 922 923 924 925
}
EXPORT_SYMBOL(module_refcount);

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

926 927
SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
		unsigned int, flags)
L
Linus Torvalds 已提交
928 929
{
	struct module *mod;
930
	char name[MODULE_NAME_LEN];
L
Linus Torvalds 已提交
931 932
	int ret, forced = 0;

933
	if (!capable(CAP_SYS_MODULE) || modules_disabled)
934 935 936 937 938 939
		return -EPERM;

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

940 941
	if (mutex_lock_interruptible(&module_mutex) != 0)
		return -EINTR;
L
Linus Torvalds 已提交
942 943 944 945 946 947 948

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

949
	if (!list_empty(&mod->source_list)) {
L
Linus Torvalds 已提交
950 951 952 953 954 955 956
		/* 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) {
957
		/* FIXME: if (force), slam module count damn the torpedoes */
958
		pr_debug("%s already dying\n", mod->name);
L
Linus Torvalds 已提交
959 960 961 962 963
		ret = -EBUSY;
		goto out;
	}

	/* If it has an init func, it must have an exit func to unload */
R
Rusty Russell 已提交
964
	if (mod->init && !mod->exit) {
965
		forced = try_force_unload(flags);
L
Linus Torvalds 已提交
966 967 968 969 970 971 972 973 974 975 976 977
		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;

978
	mutex_unlock(&module_mutex);
L
Lucas De Marchi 已提交
979
	/* Final destruction now no one is using it. */
980
	if (mod->exit != NULL)
L
Linus Torvalds 已提交
981
		mod->exit();
982 983
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
984
	async_synchronize_full();
985

986
	/* Store the name of the last unloaded module for diagnostic purposes */
987
	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
L
Linus Torvalds 已提交
988

989 990 991
	free_module(mod);
	return 0;
out:
992
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
993 994 995
	return ret;
}

996
static inline void print_unload_info(struct seq_file *m, struct module *mod)
L
Linus Torvalds 已提交
997 998 999 1000
{
	struct module_use *use;
	int printed_something = 0;

1001
	seq_printf(m, " %i ", module_refcount(mod));
L
Linus Torvalds 已提交
1002

1003 1004 1005 1006
	/*
	 * Always include a trailing , so userspace can differentiate
	 * between this and the old multi-field proc format.
	 */
1007
	list_for_each_entry(use, &mod->source_list, source_list) {
L
Linus Torvalds 已提交
1008
		printed_something = 1;
1009
		seq_printf(m, "%s,", use->source->name);
L
Linus Torvalds 已提交
1010 1011 1012 1013
	}

	if (mod->init != NULL && mod->exit == NULL) {
		printed_something = 1;
1014
		seq_puts(m, "[permanent],");
L
Linus Torvalds 已提交
1015 1016 1017
	}

	if (!printed_something)
1018
		seq_puts(m, "-");
L
Linus Torvalds 已提交
1019 1020 1021 1022 1023 1024
}

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

R
Rusty Russell 已提交
1025
	preempt_disable();
1026
	if (!find_symbol(symbol, &owner, NULL, true, false))
L
Linus Torvalds 已提交
1027 1028
		BUG();
	module_put(owner);
R
Rusty Russell 已提交
1029
	preempt_enable();
L
Linus Torvalds 已提交
1030 1031 1032
}
EXPORT_SYMBOL(__symbol_put);

1033
/* Note this assumes addr is a function, which it currently always is. */
L
Linus Torvalds 已提交
1034 1035
void symbol_put_addr(void *addr)
{
1036
	struct module *modaddr;
1037
	unsigned long a = (unsigned long)dereference_function_descriptor(addr);
L
Linus Torvalds 已提交
1038

1039
	if (core_kernel_text(a))
1040
		return;
L
Linus Torvalds 已提交
1041

1042 1043 1044 1045 1046
	/*
	 * Even though we hold a reference on the module; we still need to
	 * disable preemption in order to safely traverse the data structure.
	 */
	preempt_disable();
1047
	modaddr = __module_text_address(a);
1048
	BUG_ON(!modaddr);
1049
	module_put(modaddr);
1050
	preempt_enable();
L
Linus Torvalds 已提交
1051 1052 1053 1054
}
EXPORT_SYMBOL_GPL(symbol_put_addr);

static ssize_t show_refcnt(struct module_attribute *mattr,
1055
			   struct module_kobject *mk, char *buffer)
L
Linus Torvalds 已提交
1056
{
1057
	return sprintf(buffer, "%i\n", module_refcount(mk->mod));
L
Linus Torvalds 已提交
1058 1059
}

1060 1061
static struct module_attribute modinfo_refcnt =
	__ATTR(refcnt, 0444, show_refcnt, NULL);
L
Linus Torvalds 已提交
1062

1063 1064 1065 1066
void __module_get(struct module *module)
{
	if (module) {
		preempt_disable();
1067
		atomic_inc(&module->refcnt);
1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079
		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();
1080 1081 1082
		/* Note: here, we can fail to get a reference */
		if (likely(module_is_live(module) &&
			   atomic_inc_not_zero(&module->refcnt) != 0))
1083
			trace_module_get(module, _RET_IP_);
1084
		else
1085 1086 1087 1088 1089 1090 1091 1092
			ret = false;

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

A
Al Viro 已提交
1093 1094
void module_put(struct module *module)
{
1095 1096
	int ret;

A
Al Viro 已提交
1097
	if (module) {
1098
		preempt_disable();
1099 1100
		ret = atomic_dec_if_positive(&module->refcnt);
		WARN_ON(ret < 0);	/* Failed to put refcount */
1101
		trace_module_put(module, _RET_IP_);
1102
		preempt_enable();
A
Al Viro 已提交
1103 1104 1105 1106
	}
}
EXPORT_SYMBOL(module_put);

L
Linus Torvalds 已提交
1107
#else /* !CONFIG_MODULE_UNLOAD */
1108
static inline void print_unload_info(struct seq_file *m, struct module *mod)
L
Linus Torvalds 已提交
1109 1110
{
	/* We don't know the usage count, or what modules are using. */
1111
	seq_puts(m, " - -");
L
Linus Torvalds 已提交
1112 1113 1114 1115 1116 1117
}

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

1118
int ref_module(struct module *a, struct module *b)
L
Linus Torvalds 已提交
1119
{
1120
	return strong_try_module_get(b);
L
Linus Torvalds 已提交
1121
}
1122
EXPORT_SYMBOL_GPL(ref_module);
L
Linus Torvalds 已提交
1123

1124
static inline int module_unload_init(struct module *mod)
L
Linus Torvalds 已提交
1125
{
1126
	return 0;
L
Linus Torvalds 已提交
1127 1128 1129
}
#endif /* CONFIG_MODULE_UNLOAD */

1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141
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';
1142
	if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1143
		buf[l++] = 'E';
1144 1145
	/*
	 * TAINT_FORCED_RMMOD: could be added.
1146
	 * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1147 1148 1149 1150 1151
	 * apply to modules.
	 */
	return l;
}

1152
static ssize_t show_initstate(struct module_attribute *mattr,
1153
			      struct module_kobject *mk, char *buffer)
1154 1155 1156
{
	const char *state = "unknown";

1157
	switch (mk->mod->state) {
1158 1159 1160 1161 1162 1163 1164 1165 1166
	case MODULE_STATE_LIVE:
		state = "live";
		break;
	case MODULE_STATE_COMING:
		state = "coming";
		break;
	case MODULE_STATE_GOING:
		state = "going";
		break;
1167 1168
	default:
		BUG();
1169 1170 1171 1172
	}
	return sprintf(buffer, "%s\n", state);
}

1173 1174
static struct module_attribute modinfo_initstate =
	__ATTR(initstate, 0444, show_initstate, NULL);
1175

1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186
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;
}

1187 1188 1189 1190 1191 1192
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)
{
1193
	return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1194 1195 1196 1197 1198 1199 1200 1201
}

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)
{
1202
	return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219
}

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);
1220

1221
static struct module_attribute *modinfo_attrs[] = {
1222
	&module_uevent,
1223 1224
	&modinfo_version,
	&modinfo_srcversion,
1225 1226 1227 1228
	&modinfo_initstate,
	&modinfo_coresize,
	&modinfo_initsize,
	&modinfo_taint,
1229
#ifdef CONFIG_MODULE_UNLOAD
1230
	&modinfo_refcnt,
1231 1232 1233 1234
#endif
	NULL,
};

L
Linus Torvalds 已提交
1235 1236
static const char vermagic[] = VERMAGIC_STRING;

1237
static int try_to_force_load(struct module *mod, const char *reason)
1238 1239
{
#ifdef CONFIG_MODULE_FORCE_LOAD
A
Andi Kleen 已提交
1240
	if (!test_taint(TAINT_FORCED_MODULE))
A
Andrew Morton 已提交
1241
		pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1242
	add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1243 1244 1245 1246 1247 1248
	return 0;
#else
	return -ENOEXEC;
#endif
}

L
Linus Torvalds 已提交
1249
#ifdef CONFIG_MODVERSIONS
1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260
/* 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
Linus Torvalds 已提交
1261 1262 1263
static int check_version(Elf_Shdr *sechdrs,
			 unsigned int versindex,
			 const char *symname,
1264
			 struct module *mod,
1265 1266
			 const unsigned long *crc,
			 const struct module *crc_owner)
L
Linus Torvalds 已提交
1267 1268 1269 1270 1271 1272 1273 1274
{
	unsigned int i, num_versions;
	struct modversion_info *versions;

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

1275 1276 1277 1278
	/* No versions at all?  modprobe --force does this. */
	if (versindex == 0)
		return try_to_force_load(mod, symname) == 0;

L
Linus Torvalds 已提交
1279 1280 1281 1282 1283 1284 1285 1286
	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;

1287
		if (versions[i].crc == maybe_relocated(*crc, crc_owner))
L
Linus Torvalds 已提交
1288
			return 1;
1289
		pr_debug("Found checksum %lX vs module %lX\n",
1290
		       maybe_relocated(*crc, crc_owner), versions[i].crc);
1291
		goto bad_version;
L
Linus Torvalds 已提交
1292
	}
1293

A
Andrew Morton 已提交
1294
	pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1295
	return 0;
1296 1297

bad_version:
1298
	pr_warn("%s: disagrees about version of symbol %s\n",
1299 1300
	       mod->name, symname);
	return 0;
L
Linus Torvalds 已提交
1301 1302 1303 1304 1305 1306 1307 1308
}

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

1309 1310 1311 1312 1313
	/*
	 * Since this should be found in kernel (which can't be removed), no
	 * locking is necessary -- use preempt_disable() to placate lockdep.
	 */
	preempt_disable();
R
Rusty Russell 已提交
1314
	if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1315 1316
			 &crc, true, false)) {
		preempt_enable();
L
Linus Torvalds 已提交
1317
		BUG();
1318 1319
	}
	preempt_enable();
1320 1321
	return check_version(sechdrs, versindex,
			     VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1322
			     NULL);
L
Linus Torvalds 已提交
1323 1324
}

1325 1326 1327
/* 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
Linus Torvalds 已提交
1328
{
1329 1330 1331 1332
	if (has_crcs) {
		amagic += strcspn(amagic, " ");
		bmagic += strcspn(bmagic, " ");
	}
L
Linus Torvalds 已提交
1333 1334 1335 1336 1337 1338
	return strcmp(amagic, bmagic) == 0;
}
#else
static inline int check_version(Elf_Shdr *sechdrs,
				unsigned int versindex,
				const char *symname,
1339
				struct module *mod,
1340 1341
				const unsigned long *crc,
				const struct module *crc_owner)
L
Linus Torvalds 已提交
1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352
{
	return 1;
}

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

1353 1354
static inline int same_magic(const char *amagic, const char *bmagic,
			     bool has_crcs)
L
Linus Torvalds 已提交
1355 1356 1357 1358 1359
{
	return strcmp(amagic, bmagic) == 0;
}
#endif /* CONFIG_MODVERSIONS */

1360
/* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1361 1362
static const struct kernel_symbol *resolve_symbol(struct module *mod,
						  const struct load_info *info,
1363
						  const char *name,
1364
						  char ownername[])
L
Linus Torvalds 已提交
1365 1366
{
	struct module *owner;
1367
	const struct kernel_symbol *sym;
L
Linus Torvalds 已提交
1368
	const unsigned long *crc;
1369
	int err;
L
Linus Torvalds 已提交
1370

1371 1372 1373 1374 1375 1376
	/*
	 * 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();
1377
	mutex_lock(&module_mutex);
1378
	sym = find_symbol(name, &owner, &crc,
A
Andi Kleen 已提交
1379
			  !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1380 1381 1382
	if (!sym)
		goto unlock;

1383 1384
	if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
			   owner)) {
1385 1386
		sym = ERR_PTR(-EINVAL);
		goto getname;
L
Linus Torvalds 已提交
1387
	}
1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398

	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:
1399
	mutex_unlock(&module_mutex);
1400
	return sym;
L
Linus Torvalds 已提交
1401 1402
}

1403 1404 1405 1406
static const struct kernel_symbol *
resolve_symbol_wait(struct module *mod,
		    const struct load_info *info,
		    const char *name)
1407 1408
{
	const struct kernel_symbol *ksym;
1409
	char owner[MODULE_NAME_LEN];
1410 1411

	if (wait_event_interruptible_timeout(module_wq,
1412 1413
			!IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
			|| PTR_ERR(ksym) != -EBUSY,
1414
					     30 * HZ) <= 0) {
A
Andrew Morton 已提交
1415 1416
		pr_warn("%s: gave up waiting for init of module %s.\n",
			mod->name, owner);
1417 1418 1419 1420
	}
	return ksym;
}

L
Linus Torvalds 已提交
1421 1422 1423 1424
/*
 * /sys/module/foo/sections stuff
 * J. Corbet <corbet@lwn.net>
 */
R
Rusty Russell 已提交
1425
#ifdef CONFIG_SYSFS
1426

R
Rusty Russell 已提交
1427
#ifdef CONFIG_KALLSYMS
1428 1429 1430 1431 1432
static inline bool sect_empty(const Elf_Shdr *sect)
{
	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
}

1433
struct module_sect_attr {
1434 1435 1436 1437 1438
	struct module_attribute mattr;
	char *name;
	unsigned long address;
};

1439
struct module_sect_attrs {
1440 1441 1442 1443 1444
	struct attribute_group grp;
	unsigned int nsections;
	struct module_sect_attr attrs[0];
};

L
Linus Torvalds 已提交
1445
static ssize_t module_sect_show(struct module_attribute *mattr,
1446
				struct module_kobject *mk, char *buf)
L
Linus Torvalds 已提交
1447 1448 1449
{
	struct module_sect_attr *sattr =
		container_of(mattr, struct module_sect_attr, mattr);
1450
	return sprintf(buf, "0x%pK\n", (void *)sattr->address);
L
Linus Torvalds 已提交
1451 1452
}

1453 1454
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
1455
	unsigned int section;
1456 1457 1458 1459 1460 1461

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

R
Rusty Russell 已提交
1462
static void add_sect_attrs(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
1463 1464 1465 1466 1467
{
	unsigned int nloaded = 0, i, size[2];
	struct module_sect_attrs *sect_attrs;
	struct module_sect_attr *sattr;
	struct attribute **gattr;
D
Daniel Walker 已提交
1468

L
Linus Torvalds 已提交
1469
	/* Count loaded sections and allocate structures */
R
Rusty Russell 已提交
1470 1471
	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]))
L
Linus Torvalds 已提交
1472 1473 1474 1475 1476
			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]);
1477 1478
	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
	if (sect_attrs == NULL)
L
Linus Torvalds 已提交
1479 1480 1481 1482 1483 1484
		return;

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

1485
	sect_attrs->nsections = 0;
L
Linus Torvalds 已提交
1486 1487
	sattr = &sect_attrs->attrs[0];
	gattr = &sect_attrs->grp.attrs[0];
R
Rusty Russell 已提交
1488 1489 1490
	for (i = 0; i < info->hdr->e_shnum; i++) {
		Elf_Shdr *sec = &info->sechdrs[i];
		if (sect_empty(sec))
1491
			continue;
R
Rusty Russell 已提交
1492 1493
		sattr->address = sec->sh_addr;
		sattr->name = kstrdup(info->secstrings + sec->sh_name,
1494 1495 1496 1497
					GFP_KERNEL);
		if (sattr->name == NULL)
			goto out;
		sect_attrs->nsections++;
1498
		sysfs_attr_init(&sattr->mattr.attr);
L
Linus Torvalds 已提交
1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512
		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:
1513
	free_sect_attrs(sect_attrs);
L
Linus Torvalds 已提交
1514 1515 1516 1517 1518 1519 1520 1521 1522
}

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. */
1523
		free_sect_attrs(mod->sect_attrs);
L
Linus Torvalds 已提交
1524 1525 1526 1527
		mod->sect_attrs = NULL;
	}
}

R
Roland McGrath 已提交
1528 1529 1530 1531 1532 1533 1534 1535 1536 1537
/*
 * /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];
};

1538
static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
R
Roland McGrath 已提交
1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555
				 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]);
1556
		kobject_put(notes_attrs->dir);
R
Roland McGrath 已提交
1557 1558 1559 1560
	}
	kfree(notes_attrs);
}

R
Rusty Russell 已提交
1561
static void add_notes_attrs(struct module *mod, const struct load_info *info)
R
Roland McGrath 已提交
1562 1563 1564 1565 1566
{
	unsigned int notes, loaded, i;
	struct module_notes_attrs *notes_attrs;
	struct bin_attribute *nattr;

1567 1568 1569 1570
	/* failed to create section attributes, so can't create notes */
	if (!mod->sect_attrs)
		return;

R
Roland McGrath 已提交
1571 1572
	/* Count notes sections and allocate structures.  */
	notes = 0;
R
Rusty Russell 已提交
1573 1574 1575
	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]) &&
		    (info->sechdrs[i].sh_type == SHT_NOTE))
R
Roland McGrath 已提交
1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588
			++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
1589 1590
	for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
		if (sect_empty(&info->sechdrs[i]))
R
Roland McGrath 已提交
1591
			continue;
R
Rusty Russell 已提交
1592
		if (info->sechdrs[i].sh_type == SHT_NOTE) {
1593
			sysfs_bin_attr_init(nattr);
R
Roland McGrath 已提交
1594 1595
			nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
			nattr->attr.mode = S_IRUGO;
R
Rusty Russell 已提交
1596 1597
			nattr->size = info->sechdrs[i].sh_size;
			nattr->private = (void *) info->sechdrs[i].sh_addr;
R
Roland McGrath 已提交
1598 1599 1600 1601 1602 1603
			nattr->read = module_notes_read;
			++nattr;
		}
		++loaded;
	}

1604
	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
R
Roland McGrath 已提交
1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625
	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
1626
#else
1627

R
Rusty Russell 已提交
1628 1629
static inline void add_sect_attrs(struct module *mod,
				  const struct load_info *info)
L
Linus Torvalds 已提交
1630 1631 1632 1633 1634 1635
{
}

static inline void remove_sect_attrs(struct module *mod)
{
}
R
Roland McGrath 已提交
1636

R
Rusty Russell 已提交
1637 1638
static inline void add_notes_attrs(struct module *mod,
				   const struct load_info *info)
R
Roland McGrath 已提交
1639 1640 1641 1642 1643 1644
{
}

static inline void remove_notes_attrs(struct module *mod)
{
}
R
Rusty Russell 已提交
1645
#endif /* CONFIG_KALLSYMS */
L
Linus Torvalds 已提交
1646

1647 1648 1649 1650 1651 1652
static void add_usage_links(struct module *mod)
{
#ifdef CONFIG_MODULE_UNLOAD
	struct module_use *use;
	int nowarn;

1653
	mutex_lock(&module_mutex);
1654 1655 1656 1657
	list_for_each_entry(use, &mod->target_list, target_list) {
		nowarn = sysfs_create_link(use->target->holders_dir,
					   &mod->mkobj.kobj, mod->name);
	}
1658
	mutex_unlock(&module_mutex);
1659 1660 1661 1662 1663 1664 1665 1666
#endif
}

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

1667
	mutex_lock(&module_mutex);
1668 1669
	list_for_each_entry(use, &mod->target_list, target_list)
		sysfs_remove_link(use->target->holders_dir, mod->name);
1670
	mutex_unlock(&module_mutex);
1671 1672 1673
#endif
}

1674
static int module_add_modinfo_attrs(struct module *mod)
1675 1676
{
	struct module_attribute *attr;
1677
	struct module_attribute *temp_attr;
1678 1679 1680
	int error = 0;
	int i;

1681 1682 1683 1684 1685 1686 1687
	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;
1688 1689
	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
		if (!attr->test ||
1690 1691
		    (attr->test && attr->test(mod))) {
			memcpy(temp_attr, attr, sizeof(*temp_attr));
1692
			sysfs_attr_init(&temp_attr->attr);
1693 1694
			error = sysfs_create_file(&mod->mkobj.kobj,
					&temp_attr->attr);
1695 1696
			++temp_attr;
		}
1697 1698 1699 1700
	}
	return error;
}

1701
static void module_remove_modinfo_attrs(struct module *mod)
1702 1703 1704 1705
{
	struct module_attribute *attr;
	int i;

1706 1707 1708 1709
	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
		/* pick a field to test for end of list */
		if (!attr->attr.name)
			break;
1710
		sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1711 1712
		if (attr->free)
			attr->free(mod);
1713
	}
1714
	kfree(mod->modinfo_attrs);
1715
}
L
Linus Torvalds 已提交
1716

1717 1718 1719 1720 1721 1722 1723 1724
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);
}

1725
static int mod_sysfs_init(struct module *mod)
L
Linus Torvalds 已提交
1726 1727
{
	int err;
1728
	struct kobject *kobj;
L
Linus Torvalds 已提交
1729

1730
	if (!module_sysfs_initialized) {
A
Andrew Morton 已提交
1731
		pr_err("%s: module sysfs not initialized\n", mod->name);
1732 1733 1734
		err = -EINVAL;
		goto out;
	}
1735 1736 1737

	kobj = kset_find_obj(module_kset, mod->name);
	if (kobj) {
A
Andrew Morton 已提交
1738
		pr_err("%s: module is already loaded\n", mod->name);
1739 1740 1741 1742 1743
		kobject_put(kobj);
		err = -EINVAL;
		goto out;
	}

L
Linus Torvalds 已提交
1744
	mod->mkobj.mod = mod;
1745

1746 1747 1748 1749 1750
	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)
1751
		mod_kobject_put(mod);
K
Kay Sievers 已提交
1752

1753
	/* delay uevent until full sysfs population */
K
Kay Sievers 已提交
1754 1755 1756 1757
out:
	return err;
}

1758
static int mod_sysfs_setup(struct module *mod,
R
Rusty Russell 已提交
1759
			   const struct load_info *info,
K
Kay Sievers 已提交
1760 1761 1762 1763 1764
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	int err;

1765 1766 1767 1768
	err = mod_sysfs_init(mod);
	if (err)
		goto out;

1769
	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1770 1771
	if (!mod->holders_dir) {
		err = -ENOMEM;
K
Kay Sievers 已提交
1772
		goto out_unreg;
1773
	}
K
Kay Sievers 已提交
1774

L
Linus Torvalds 已提交
1775 1776
	err = module_param_sysfs_setup(mod, kparam, num_params);
	if (err)
K
Kay Sievers 已提交
1777
		goto out_unreg_holders;
L
Linus Torvalds 已提交
1778

1779 1780
	err = module_add_modinfo_attrs(mod);
	if (err)
1781
		goto out_unreg_param;
1782

1783
	add_usage_links(mod);
R
Rusty Russell 已提交
1784 1785
	add_sect_attrs(mod, info);
	add_notes_attrs(mod, info);
1786

1787
	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
L
Linus Torvalds 已提交
1788 1789
	return 0;

1790 1791
out_unreg_param:
	module_param_sysfs_remove(mod);
K
Kay Sievers 已提交
1792
out_unreg_holders:
1793
	kobject_put(mod->holders_dir);
K
Kay Sievers 已提交
1794
out_unreg:
1795
	mod_kobject_put(mod);
1796
out:
L
Linus Torvalds 已提交
1797 1798
	return err;
}
1799 1800 1801

static void mod_sysfs_fini(struct module *mod)
{
R
Rusty Russell 已提交
1802 1803
	remove_notes_attrs(mod);
	remove_sect_attrs(mod);
1804
	mod_kobject_put(mod);
1805 1806
}

1807 1808 1809 1810
static void init_param_lock(struct module *mod)
{
	mutex_init(&mod->param_lock);
}
R
Rusty Russell 已提交
1811
#else /* !CONFIG_SYSFS */
1812

R
Rusty Russell 已提交
1813 1814
static int mod_sysfs_setup(struct module *mod,
			   const struct load_info *info,
1815 1816 1817 1818 1819 1820
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	return 0;
}

1821 1822 1823 1824
static void mod_sysfs_fini(struct module *mod)
{
}

1825 1826 1827 1828
static void module_remove_modinfo_attrs(struct module *mod)
{
}

1829 1830 1831 1832
static void del_usage_links(struct module *mod)
{
}

1833 1834 1835
static void init_param_lock(struct module *mod)
{
}
1836
#endif /* CONFIG_SYSFS */
L
Linus Torvalds 已提交
1837

1838
static void mod_sysfs_teardown(struct module *mod)
L
Linus Torvalds 已提交
1839
{
1840
	del_usage_links(mod);
1841
	module_remove_modinfo_attrs(mod);
L
Linus Torvalds 已提交
1842
	module_param_sysfs_remove(mod);
1843 1844
	kobject_put(mod->mkobj.drivers_dir);
	kobject_put(mod->holders_dir);
1845
	mod_sysfs_fini(mod);
L
Linus Torvalds 已提交
1846 1847
}

1848 1849 1850 1851
#ifdef CONFIG_DEBUG_SET_MODULE_RONX
/*
 * LKM RO/NX protection: protect module's text/ro-data
 * from modification and any data from execution.
R
Rusty Russell 已提交
1852 1853 1854 1855 1856 1857 1858 1859
 *
 * General layout of module is:
 *          [text] [read-only-data] [writable data]
 * text_size -----^                ^               ^
 * ro_size ------------------------|               |
 * size -------------------------------------------|
 *
 * These values are always page-aligned (as is base)
1860
 */
R
Rusty Russell 已提交
1861 1862
static void frob_text(const struct module_layout *layout,
		      int (*set_memory)(unsigned long start, int num_pages))
1863
{
R
Rusty Russell 已提交
1864 1865 1866 1867
	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
	BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
	set_memory((unsigned long)layout->base,
		   layout->text_size >> PAGE_SHIFT);
1868 1869
}

R
Rusty Russell 已提交
1870 1871
static void frob_rodata(const struct module_layout *layout,
			int (*set_memory)(unsigned long start, int num_pages))
1872
{
R
Rusty Russell 已提交
1873 1874 1875 1876 1877
	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
	BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
	BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
	set_memory((unsigned long)layout->base + layout->text_size,
		   (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1878 1879
}

R
Rusty Russell 已提交
1880 1881
static void frob_writable_data(const struct module_layout *layout,
			       int (*set_memory)(unsigned long start, int num_pages))
1882
{
R
Rusty Russell 已提交
1883 1884 1885 1886 1887
	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
	BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
	BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
	set_memory((unsigned long)layout->base + layout->ro_size,
		   (layout->size - layout->ro_size) >> PAGE_SHIFT);
1888 1889
}

R
Rusty Russell 已提交
1890 1891
/* livepatching wants to disable read-only so it can frob module. */
void module_disable_ro(const struct module *mod)
1892
{
R
Rusty Russell 已提交
1893 1894 1895 1896
	frob_text(&mod->core_layout, set_memory_rw);
	frob_rodata(&mod->core_layout, set_memory_rw);
	frob_text(&mod->init_layout, set_memory_rw);
	frob_rodata(&mod->init_layout, set_memory_rw);
1897
}
1898

R
Rusty Russell 已提交
1899
void module_enable_ro(const struct module *mod)
1900
{
R
Rusty Russell 已提交
1901 1902 1903 1904
	frob_text(&mod->core_layout, set_memory_ro);
	frob_rodata(&mod->core_layout, set_memory_ro);
	frob_text(&mod->init_layout, set_memory_ro);
	frob_rodata(&mod->init_layout, set_memory_ro);
1905 1906
}

R
Rusty Russell 已提交
1907
static void module_enable_nx(const struct module *mod)
1908
{
R
Rusty Russell 已提交
1909 1910 1911 1912
	frob_rodata(&mod->core_layout, set_memory_nx);
	frob_writable_data(&mod->core_layout, set_memory_nx);
	frob_rodata(&mod->init_layout, set_memory_nx);
	frob_writable_data(&mod->init_layout, set_memory_nx);
1913 1914
}

R
Rusty Russell 已提交
1915
static void module_disable_nx(const struct module *mod)
1916
{
R
Rusty Russell 已提交
1917 1918 1919 1920
	frob_rodata(&mod->core_layout, set_memory_x);
	frob_writable_data(&mod->core_layout, set_memory_x);
	frob_rodata(&mod->init_layout, set_memory_x);
	frob_writable_data(&mod->init_layout, set_memory_x);
1921 1922 1923
}

/* Iterate through all modules and set each module's text as RW */
1924
void set_all_modules_text_rw(void)
1925 1926 1927 1928 1929
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1930 1931
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
R
Rusty Russell 已提交
1932 1933 1934

		frob_text(&mod->core_layout, set_memory_rw);
		frob_text(&mod->init_layout, set_memory_rw);
1935 1936 1937 1938 1939
	}
	mutex_unlock(&module_mutex);
}

/* Iterate through all modules and set each module's text as RO */
1940
void set_all_modules_text_ro(void)
1941 1942 1943 1944 1945
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1946 1947
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
R
Rusty Russell 已提交
1948 1949 1950

		frob_text(&mod->core_layout, set_memory_ro);
		frob_text(&mod->init_layout, set_memory_ro);
1951 1952 1953
	}
	mutex_unlock(&module_mutex);
}
R
Rusty Russell 已提交
1954 1955 1956 1957 1958 1959 1960 1961 1962

static void disable_ro_nx(const struct module_layout *layout)
{
	frob_text(layout, set_memory_rw);
	frob_rodata(layout, set_memory_rw);
	frob_rodata(layout, set_memory_x);
	frob_writable_data(layout, set_memory_x);
}

1963
#else
R
Rusty Russell 已提交
1964 1965 1966
static void disable_ro_nx(const struct module_layout *layout) { }
static void module_enable_nx(const struct module *mod) { }
static void module_disable_nx(const struct module *mod) { }
1967 1968
#endif

1969
void __weak module_memfree(void *module_region)
1970 1971 1972 1973 1974 1975 1976 1977
{
	vfree(module_region);
}

void __weak module_arch_cleanup(struct module *mod)
{
}

1978 1979 1980 1981
void __weak module_arch_freeing_init(struct module *mod)
{
}

1982
/* Free a module, remove from lists, etc. */
L
Linus Torvalds 已提交
1983 1984
static void free_module(struct module *mod)
{
1985 1986
	trace_module_free(mod);

1987
	mod_sysfs_teardown(mod);
L
Linus Torvalds 已提交
1988

1989 1990
	/* We leave it in list to prevent duplicate loads, but make sure
	 * that noone uses it while it's being deconstructed. */
1991
	mutex_lock(&module_mutex);
1992
	mod->state = MODULE_STATE_UNFORMED;
1993
	mutex_unlock(&module_mutex);
1994

1995 1996 1997
	/* Remove dynamic debug info */
	ddebug_remove_module(mod->name);

L
Linus Torvalds 已提交
1998 1999 2000 2001 2002 2003
	/* Arch-specific cleanup. */
	module_arch_cleanup(mod);

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

2004 2005 2006
	/* Free any allocated parameters. */
	destroy_params(mod->kp, mod->num_kp);

2007 2008
	/* Now we can delete it from the lists */
	mutex_lock(&module_mutex);
2009 2010
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
2011
	mod_tree_remove(mod);
2012
	/* Remove this module from bug list, this uses list_del_rcu */
2013
	module_bug_cleanup(mod);
2014 2015
	/* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
	synchronize_sched();
2016 2017
	mutex_unlock(&module_mutex);

R
Rusty Russell 已提交
2018 2019
	/* This may be empty, but that's OK */
	disable_ro_nx(&mod->init_layout);
2020
	module_arch_freeing_init(mod);
2021
	module_memfree(mod->init_layout.base);
L
Linus Torvalds 已提交
2022
	kfree(mod->args);
2023
	percpu_modfree(mod);
2024

2025
	/* Free lock-classes; relies on the preceding sync_rcu(). */
2026
	lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
I
Ingo Molnar 已提交
2027

L
Linus Torvalds 已提交
2028
	/* Finally, free the core (containing the module structure) */
R
Rusty Russell 已提交
2029
	disable_ro_nx(&mod->core_layout);
2030
	module_memfree(mod->core_layout.base);
2031 2032 2033 2034

#ifdef CONFIG_MPU
	update_protections(current->mm);
#endif
L
Linus Torvalds 已提交
2035 2036 2037 2038 2039
}

void *__symbol_get(const char *symbol)
{
	struct module *owner;
2040
	const struct kernel_symbol *sym;
L
Linus Torvalds 已提交
2041

R
Rusty Russell 已提交
2042
	preempt_disable();
2043 2044 2045
	sym = find_symbol(symbol, &owner, NULL, true, true);
	if (sym && strong_try_module_get(owner))
		sym = NULL;
R
Rusty Russell 已提交
2046
	preempt_enable();
L
Linus Torvalds 已提交
2047

2048
	return sym ? (void *)sym->value : NULL;
L
Linus Torvalds 已提交
2049 2050 2051
}
EXPORT_SYMBOL_GPL(__symbol_get);

2052 2053
/*
 * Ensure that an exported symbol [global namespace] does not already exist
2054
 * in the kernel or in some other module's exported symbol table.
2055 2056
 *
 * You must hold the module_mutex.
2057 2058 2059
 */
static int verify_export_symbols(struct module *mod)
{
2060
	unsigned int i;
2061
	struct module *owner;
2062 2063 2064 2065 2066 2067 2068 2069
	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 },
2070
#ifdef CONFIG_UNUSED_SYMBOLS
2071 2072
		{ mod->unused_syms, mod->num_unused_syms },
		{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2073
#endif
2074
	};
2075

2076 2077
	for (i = 0; i < ARRAY_SIZE(arr); i++) {
		for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2078
			if (find_symbol(s->name, &owner, NULL, true, false)) {
A
Andrew Morton 已提交
2079
				pr_err("%s: exports duplicate symbol %s"
2080 2081 2082 2083
				       " (owned by %s)\n",
				       mod->name, s->name, module_name(owner));
				return -ENOEXEC;
			}
2084
		}
2085 2086
	}
	return 0;
2087 2088
}

2089
/* Change all symbols so that st_value encodes the pointer directly. */
2090 2091 2092 2093
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
2094
	unsigned long secbase;
2095
	unsigned int i;
L
Linus Torvalds 已提交
2096
	int ret = 0;
2097
	const struct kernel_symbol *ksym;
L
Linus Torvalds 已提交
2098

2099 2100 2101
	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
2102 2103
		switch (sym[i].st_shndx) {
		case SHN_COMMON:
2104 2105 2106 2107
			/* Ignore common symbols */
			if (!strncmp(name, "__gnu_lto", 9))
				break;

L
Linus Torvalds 已提交
2108 2109
			/* We compiled with -fno-common.  These are not
			   supposed to happen.  */
2110
			pr_debug("Common symbol: %s\n", name);
2111
			pr_warn("%s: please compile with -fno-common\n",
L
Linus Torvalds 已提交
2112 2113 2114 2115 2116 2117
			       mod->name);
			ret = -ENOEXEC;
			break;

		case SHN_ABS:
			/* Don't need to do anything */
2118
			pr_debug("Absolute symbol: 0x%08lx\n",
L
Linus Torvalds 已提交
2119 2120 2121 2122
			       (long)sym[i].st_value);
			break;

		case SHN_UNDEF:
2123
			ksym = resolve_symbol_wait(mod, info, name);
L
Linus Torvalds 已提交
2124
			/* Ok if resolved.  */
2125
			if (ksym && !IS_ERR(ksym)) {
2126
				sym[i].st_value = ksym->value;
L
Linus Torvalds 已提交
2127
				break;
2128 2129
			}

L
Linus Torvalds 已提交
2130
			/* Ok if weak.  */
2131
			if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
L
Linus Torvalds 已提交
2132 2133
				break;

A
Andrew Morton 已提交
2134 2135
			pr_warn("%s: Unknown symbol %s (err %li)\n",
				mod->name, name, PTR_ERR(ksym));
2136
			ret = PTR_ERR(ksym) ?: -ENOENT;
L
Linus Torvalds 已提交
2137 2138 2139 2140
			break;

		default:
			/* Divert to percpu allocation if a percpu var. */
2141
			if (sym[i].st_shndx == info->index.pcpu)
2142
				secbase = (unsigned long)mod_percpu(mod);
L
Linus Torvalds 已提交
2143
			else
2144
				secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
L
Linus Torvalds 已提交
2145 2146 2147 2148 2149 2150 2151 2152
			sym[i].st_value += secbase;
			break;
		}
	}

	return ret;
}

2153
static int apply_relocations(struct module *mod, const struct load_info *info)
2154 2155 2156 2157 2158
{
	unsigned int i;
	int err = 0;

	/* Now do relocations. */
2159 2160
	for (i = 1; i < info->hdr->e_shnum; i++) {
		unsigned int infosec = info->sechdrs[i].sh_info;
2161 2162

		/* Not a valid relocation section? */
2163
		if (infosec >= info->hdr->e_shnum)
2164 2165 2166
			continue;

		/* Don't bother with non-allocated sections */
2167
		if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2168 2169
			continue;

2170 2171 2172 2173 2174 2175
		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);
2176 2177 2178 2179 2180 2181
		if (err < 0)
			break;
	}
	return err;
}

2182 2183 2184 2185 2186 2187 2188 2189
/* 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
2190
/* Update size with this section: return offset. */
2191 2192
static long get_offset(struct module *mod, unsigned int *size,
		       Elf_Shdr *sechdr, unsigned int section)
L
Linus Torvalds 已提交
2193 2194 2195
{
	long ret;

2196
	*size += arch_mod_section_prepend(mod, section);
L
Linus Torvalds 已提交
2197 2198 2199 2200 2201 2202 2203 2204 2205
	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. */
2206
static void layout_sections(struct module *mod, struct load_info *info)
L
Linus Torvalds 已提交
2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218
{
	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;

2219 2220
	for (i = 0; i < info->hdr->e_shnum; i++)
		info->sechdrs[i].sh_entsize = ~0UL;
L
Linus Torvalds 已提交
2221

2222
	pr_debug("Core section allocation order:\n");
L
Linus Torvalds 已提交
2223
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2224 2225 2226
		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
2227 2228 2229 2230

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2231
			    || strstarts(sname, ".init"))
L
Linus Torvalds 已提交
2232
				continue;
2233
			s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2234
			pr_debug("\t%s\n", sname);
L
Linus Torvalds 已提交
2235
		}
2236 2237
		switch (m) {
		case 0: /* executable */
2238 2239
			mod->core_layout.size = debug_align(mod->core_layout.size);
			mod->core_layout.text_size = mod->core_layout.size;
2240 2241
			break;
		case 1: /* RO: text and ro-data */
2242 2243
			mod->core_layout.size = debug_align(mod->core_layout.size);
			mod->core_layout.ro_size = mod->core_layout.size;
2244 2245
			break;
		case 3: /* whole core */
2246
			mod->core_layout.size = debug_align(mod->core_layout.size);
2247 2248
			break;
		}
L
Linus Torvalds 已提交
2249 2250
	}

2251
	pr_debug("Init section allocation order:\n");
L
Linus Torvalds 已提交
2252
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2253 2254 2255
		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
2256 2257 2258 2259

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2260
			    || !strstarts(sname, ".init"))
L
Linus Torvalds 已提交
2261
				continue;
2262
			s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
L
Linus Torvalds 已提交
2263
					 | INIT_OFFSET_MASK);
2264
			pr_debug("\t%s\n", sname);
L
Linus Torvalds 已提交
2265
		}
2266 2267
		switch (m) {
		case 0: /* executable */
2268 2269
			mod->init_layout.size = debug_align(mod->init_layout.size);
			mod->init_layout.text_size = mod->init_layout.size;
2270 2271
			break;
		case 1: /* RO: text and ro-data */
2272 2273
			mod->init_layout.size = debug_align(mod->init_layout.size);
			mod->init_layout.ro_size = mod->init_layout.size;
2274 2275
			break;
		case 3: /* whole init */
2276
			mod->init_layout.size = debug_align(mod->init_layout.size);
2277 2278
			break;
		}
L
Linus Torvalds 已提交
2279 2280 2281 2282 2283 2284 2285 2286
	}
}

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

2287
	if (!license_is_gpl_compatible(license)) {
A
Andi Kleen 已提交
2288
		if (!test_taint(TAINT_PROPRIETARY_MODULE))
A
Andrew Morton 已提交
2289 2290
			pr_warn("%s: module license '%s' taints kernel.\n",
				mod->name, license);
2291 2292
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
L
Linus Torvalds 已提交
2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314
	}
}

/* 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;
}

2315
static char *get_modinfo(struct load_info *info, const char *tag)
L
Linus Torvalds 已提交
2316 2317 2318
{
	char *p;
	unsigned int taglen = strlen(tag);
2319 2320
	Elf_Shdr *infosec = &info->sechdrs[info->index.info];
	unsigned long size = infosec->sh_size;
L
Linus Torvalds 已提交
2321

2322
	for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
L
Linus Torvalds 已提交
2323 2324 2325 2326 2327 2328
		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
			return p + taglen + 1;
	}
	return NULL;
}

2329
static void setup_modinfo(struct module *mod, struct load_info *info)
2330 2331 2332 2333 2334 2335
{
	struct module_attribute *attr;
	int i;

	for (i = 0; (attr = modinfo_attrs[i]); i++) {
		if (attr->setup)
2336
			attr->setup(mod, get_modinfo(info, attr->attr.name));
2337 2338 2339
	}
}

2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350
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
2351
#ifdef CONFIG_KALLSYMS
2352 2353 2354 2355 2356 2357

/* 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)
{
2358 2359
	return bsearch(name, start, stop - start,
			sizeof(struct kernel_symbol), cmp_name);
2360 2361
}

2362 2363
static int is_exported(const char *name, unsigned long value,
		       const struct module *mod)
L
Linus Torvalds 已提交
2364
{
2365 2366 2367
	const struct kernel_symbol *ks;
	if (!mod)
		ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2368
	else
2369 2370
		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
	return ks != NULL && ks->value == value;
L
Linus Torvalds 已提交
2371 2372 2373
}

/* As per nm */
2374
static char elf_type(const Elf_Sym *sym, const struct load_info *info)
L
Linus Torvalds 已提交
2375
{
2376 2377
	const Elf_Shdr *sechdrs = info->sechdrs;

L
Linus Torvalds 已提交
2378 2379 2380 2381 2382 2383 2384 2385
	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';
2386
	if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
L
Linus Torvalds 已提交
2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406
		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';
	}
2407 2408
	if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
		      ".debug")) {
L
Linus Torvalds 已提交
2409
		return 'n';
2410
	}
L
Linus Torvalds 已提交
2411 2412 2413
	return '?';
}

2414
static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2415
			unsigned int shnum, unsigned int pcpundx)
2416 2417 2418 2419 2420 2421 2422 2423
{
	const Elf_Shdr *sec;

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

2424 2425 2426 2427 2428
#ifdef CONFIG_KALLSYMS_ALL
	if (src->st_shndx == pcpundx)
		return true;
#endif

2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439
	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;
}

2440 2441 2442 2443 2444 2445 2446
/*
 * 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>.
 */
2447
static void layout_symtab(struct module *mod, struct load_info *info)
2448
{
2449 2450
	Elf_Shdr *symsect = info->sechdrs + info->index.sym;
	Elf_Shdr *strsect = info->sechdrs + info->index.str;
2451
	const Elf_Sym *src;
2452
	unsigned int i, nsrc, ndst, strtab_size = 0;
2453 2454 2455

	/* Put symbol section at end of init part of module. */
	symsect->sh_flags |= SHF_ALLOC;
2456
	symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2457
					 info->index.sym) | INIT_OFFSET_MASK;
2458
	pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2459

2460
	src = (void *)info->hdr + symsect->sh_offset;
2461
	nsrc = symsect->sh_size / sizeof(*src);
2462

2463
	/* Compute total space required for the core symbols' strtab. */
2464 2465
	for (ndst = i = 0; i < nsrc; i++) {
		if (i == 0 ||
2466 2467
		    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
				   info->index.pcpu)) {
2468
			strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2469
			ndst++;
2470
		}
2471
	}
2472 2473

	/* Append room for core symbols at end of core part. */
2474 2475 2476 2477
	info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
	info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
	mod->core_layout.size += strtab_size;
	mod->core_layout.size = debug_align(mod->core_layout.size);
2478

2479 2480
	/* Put string table section at end of init part of module. */
	strsect->sh_flags |= SHF_ALLOC;
2481
	strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2482
					 info->index.str) | INIT_OFFSET_MASK;
2483
	mod->init_layout.size = debug_align(mod->init_layout.size);
2484
	pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2485 2486
}

2487
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2488
{
2489 2490 2491
	unsigned int i, ndst;
	const Elf_Sym *src;
	Elf_Sym *dst;
2492
	char *s;
2493
	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
L
Linus Torvalds 已提交
2494

2495 2496
	mod->symtab = (void *)symsec->sh_addr;
	mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2497 2498
	/* 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
2499 2500 2501

	/* Set types up while we still have access to sections. */
	for (i = 0; i < mod->num_symtab; i++)
2502
		mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2503

2504 2505
	mod->core_symtab = dst = mod->core_layout.base + info->symoffs;
	mod->core_strtab = s = mod->core_layout.base + info->stroffs;
2506
	src = mod->symtab;
2507 2508
	for (ndst = i = 0; i < mod->num_symtab; i++) {
		if (i == 0 ||
2509 2510
		    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
				   info->index.pcpu)) {
2511 2512 2513 2514 2515
			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;
		}
2516 2517
	}
	mod->core_num_syms = ndst;
L
Linus Torvalds 已提交
2518 2519
}
#else
2520
static inline void layout_symtab(struct module *mod, struct load_info *info)
2521 2522
{
}
2523

2524
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2525 2526 2527 2528
{
}
#endif /* CONFIG_KALLSYMS */

2529
static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2530
{
2531 2532
	if (!debug)
		return;
2533 2534
#ifdef CONFIG_DYNAMIC_DEBUG
	if (ddebug_add_module(debug, num, debug->modname))
A
Andrew Morton 已提交
2535 2536
		pr_err("dynamic debug error adding module: %s\n",
			debug->modname);
2537
#endif
R
Rusty Russell 已提交
2538
}
2539

2540 2541 2542 2543 2544 2545
static void dynamic_debug_remove(struct _ddebug *debug)
{
	if (debug)
		ddebug_remove_module(debug->modname);
}

2546 2547
void * __weak module_alloc(unsigned long size)
{
R
Rusty Russell 已提交
2548
	return vmalloc_exec(size);
2549 2550
}

C
Catalin Marinas 已提交
2551
#ifdef CONFIG_DEBUG_KMEMLEAK
2552 2553
static void kmemleak_load_module(const struct module *mod,
				 const struct load_info *info)
C
Catalin Marinas 已提交
2554 2555 2556 2557
{
	unsigned int i;

	/* only scan the sections containing data */
2558
	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
C
Catalin Marinas 已提交
2559

2560
	for (i = 1; i < info->hdr->e_shnum; i++) {
2561 2562 2563 2564
		/* 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))
C
Catalin Marinas 已提交
2565 2566
			continue;

2567 2568
		kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
				   info->sechdrs[i].sh_size, GFP_KERNEL);
C
Catalin Marinas 已提交
2569 2570 2571
	}
}
#else
2572 2573
static inline void kmemleak_load_module(const struct module *mod,
					const struct load_info *info)
C
Catalin Marinas 已提交
2574 2575 2576 2577
{
}
#endif

R
Rusty Russell 已提交
2578
#ifdef CONFIG_MODULE_SIG
2579
static int module_sig_check(struct load_info *info)
R
Rusty Russell 已提交
2580 2581
{
	int err = -ENOKEY;
2582 2583
	const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
	const void *mod = info->hdr;
2584

2585 2586
	if (info->len > markerlen &&
	    memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2587
		/* We truncate the module to discard the signature */
2588 2589
		info->len -= markerlen;
		err = mod_verify_sig(mod, &info->len);
R
Rusty Russell 已提交
2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603
	}

	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 */
2604
static int module_sig_check(struct load_info *info)
R
Rusty Russell 已提交
2605 2606 2607 2608 2609
{
	return 0;
}
#endif /* !CONFIG_MODULE_SIG */

2610 2611
/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
static int elf_header_check(struct load_info *info)
2612
{
2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625
	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;
2626

2627 2628 2629
	return 0;
}

2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646
#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;
}

2647 2648 2649
/* Sets info->hdr and info->len. */
static int copy_module_from_user(const void __user *umod, unsigned long len,
				  struct load_info *info)
2650 2651 2652
{
	int err;

2653 2654
	info->len = len;
	if (info->len < sizeof(*(info->hdr)))
2655 2656
		return -ENOEXEC;

2657 2658 2659 2660
	err = security_kernel_module_from_file(NULL);
	if (err)
		return err;

2661
	/* Suck in entire file: we'll want most of it. */
2662 2663
	info->hdr = __vmalloc(info->len,
			GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2664
	if (!info->hdr)
2665 2666
		return -ENOMEM;

2667
	if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2668 2669
		vfree(info->hdr);
		return -EFAULT;
2670 2671
	}

2672 2673 2674 2675 2676 2677
	return 0;
}

/* Sets info->hdr and info->len. */
static int copy_module_from_fd(int fd, struct load_info *info)
{
A
Al Viro 已提交
2678
	struct fd f = fdget(fd);
2679 2680 2681 2682 2683
	int err;
	struct kstat stat;
	loff_t pos;
	ssize_t bytes = 0;

A
Al Viro 已提交
2684
	if (!f.file)
2685 2686
		return -ENOEXEC;

A
Al Viro 已提交
2687
	err = security_kernel_module_from_file(f.file);
R
Rusty Russell 已提交
2688
	if (err)
2689
		goto out;
R
Rusty Russell 已提交
2690

A
Al Viro 已提交
2691
	err = vfs_getattr(&f.file->f_path, &stat);
R
Rusty Russell 已提交
2692
	if (err)
2693
		goto out;
2694

2695 2696 2697
	if (stat.size > INT_MAX) {
		err = -EFBIG;
		goto out;
2698
	}
2699 2700 2701 2702 2703 2704 2705

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

2706 2707 2708 2709
	info->hdr = vmalloc(stat.size);
	if (!info->hdr) {
		err = -ENOMEM;
		goto out;
2710
	}
R
Rusty Russell 已提交
2711

2712 2713
	pos = 0;
	while (pos < stat.size) {
A
Al Viro 已提交
2714
		bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725
				    stat.size - pos);
		if (bytes < 0) {
			vfree(info->hdr);
			err = bytes;
			goto out;
		}
		if (bytes == 0)
			break;
		pos += bytes;
	}
	info->len = pos;
2726

2727
out:
A
Al Viro 已提交
2728
	fdput(f);
2729 2730 2731
	return err;
}

R
Rusty Russell 已提交
2732 2733 2734 2735 2736
static void free_copy(struct load_info *info)
{
	vfree(info->hdr);
}

2737
static int rewrite_section_headers(struct load_info *info, int flags)
2738 2739 2740 2741 2742 2743 2744 2745 2746 2747
{
	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) {
A
Andrew Morton 已提交
2748
			pr_err("Module len %lu truncated\n", info->len);
2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761
			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
	}
2762 2763

	/* Track but don't keep modinfo and version sections. */
2764 2765 2766 2767
	if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
		info->index.vers = 0; /* Pretend no __versions section! */
	else
		info->index.vers = find_sec(info, "__versions");
2768
	info->index.info = find_sec(info, ".modinfo");
2769 2770
	info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
	info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2771 2772 2773
	return 0;
}

L
Linus Torvalds 已提交
2774 2775 2776 2777 2778 2779 2780 2781
/*
 * 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).
 */
2782
static struct module *setup_load_info(struct load_info *info, int flags)
L
Linus Torvalds 已提交
2783 2784
{
	unsigned int i;
2785
	int err;
L
Linus Torvalds 已提交
2786 2787 2788 2789
	struct module *mod;

	/* Set up the convenience variables */
	info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2790 2791
	info->secstrings = (void *)info->hdr
		+ info->sechdrs[info->hdr->e_shstrndx].sh_offset;
L
Linus Torvalds 已提交
2792

2793
	err = rewrite_section_headers(info, flags);
2794 2795
	if (err)
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2796

2797 2798
	/* Find internal symbols and strings. */
	for (i = 1; i < info->hdr->e_shnum; i++) {
L
Linus Torvalds 已提交
2799 2800 2801
		if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
			info->index.sym = i;
			info->index.str = info->sechdrs[i].sh_link;
2802 2803 2804
			info->strtab = (char *)info->hdr
				+ info->sechdrs[info->index.str].sh_offset;
			break;
L
Linus Torvalds 已提交
2805 2806 2807
		}
	}

2808
	info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
L
Linus Torvalds 已提交
2809
	if (!info->index.mod) {
A
Andrew Morton 已提交
2810
		pr_warn("No module found in object\n");
L
Linus Torvalds 已提交
2811 2812 2813 2814 2815 2816
		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) {
A
Andrew Morton 已提交
2817
		pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
L
Linus Torvalds 已提交
2818 2819 2820
		return ERR_PTR(-ENOEXEC);
	}

2821
	info->index.pcpu = find_pcpusec(info);
L
Linus Torvalds 已提交
2822 2823 2824 2825 2826 2827 2828 2829

	/* 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;
}

2830
static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2831
{
2832
	const char *modmagic = get_modinfo(info, "vermagic");
2833 2834
	int err;

2835 2836 2837
	if (flags & MODULE_INIT_IGNORE_VERMAGIC)
		modmagic = NULL;

2838 2839 2840 2841 2842
	/* This is allowed: modprobe --force will invalidate it. */
	if (!modmagic) {
		err = try_to_force_load(mod, "bad vermagic");
		if (err)
			return err;
2843
	} else if (!same_magic(modmagic, vermagic, info->index.vers)) {
A
Andrew Morton 已提交
2844
		pr_err("%s: version magic '%s' should be '%s'\n",
2845 2846 2847 2848
		       mod->name, modmagic, vermagic);
		return -ENOEXEC;
	}

2849
	if (!get_modinfo(info, "intree"))
2850
		add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2851

2852
	if (get_modinfo(info, "staging")) {
2853
		add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
A
Andrew Morton 已提交
2854 2855
		pr_warn("%s: module is from the staging directory, the quality "
			"is unknown, you have been warned.\n", mod->name);
2856
	}
2857 2858

	/* Set up license info based on the info section */
2859
	set_license(mod, get_modinfo(info, "license"));
2860

2861 2862 2863
	return 0;
}

2864
static int find_module_sections(struct module *mod, struct load_info *info)
L
Linus Torvalds 已提交
2865
{
2866
	mod->kp = section_objs(info, "__param",
L
Linus Torvalds 已提交
2867
			       sizeof(*mod->kp), &mod->num_kp);
2868
	mod->syms = section_objs(info, "__ksymtab",
L
Linus Torvalds 已提交
2869
				 sizeof(*mod->syms), &mod->num_syms);
2870 2871
	mod->crcs = section_addr(info, "__kcrctab");
	mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
L
Linus Torvalds 已提交
2872 2873
				     sizeof(*mod->gpl_syms),
				     &mod->num_gpl_syms);
2874 2875
	mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
	mod->gpl_future_syms = section_objs(info,
L
Linus Torvalds 已提交
2876 2877 2878
					    "__ksymtab_gpl_future",
					    sizeof(*mod->gpl_future_syms),
					    &mod->num_gpl_future_syms);
2879
	mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
L
Linus Torvalds 已提交
2880 2881

#ifdef CONFIG_UNUSED_SYMBOLS
2882
	mod->unused_syms = section_objs(info, "__ksymtab_unused",
L
Linus Torvalds 已提交
2883 2884
					sizeof(*mod->unused_syms),
					&mod->num_unused_syms);
2885 2886
	mod->unused_crcs = section_addr(info, "__kcrctab_unused");
	mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
L
Linus Torvalds 已提交
2887 2888
					    sizeof(*mod->unused_gpl_syms),
					    &mod->num_unused_gpl_syms);
2889
	mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
L
Linus Torvalds 已提交
2890 2891
#endif
#ifdef CONFIG_CONSTRUCTORS
2892
	mod->ctors = section_objs(info, ".ctors",
L
Linus Torvalds 已提交
2893
				  sizeof(*mod->ctors), &mod->num_ctors);
2894 2895 2896 2897 2898 2899 2900 2901
	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.
		 */
2902
		pr_warn("%s: has both .ctors and .init_array.\n",
2903 2904 2905
		       mod->name);
		return -EINVAL;
	}
L
Linus Torvalds 已提交
2906 2907 2908
#endif

#ifdef CONFIG_TRACEPOINTS
2909 2910 2911
	mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
					     sizeof(*mod->tracepoints_ptrs),
					     &mod->num_tracepoints);
L
Linus Torvalds 已提交
2912
#endif
2913 2914 2915 2916 2917
#ifdef HAVE_JUMP_LABEL
	mod->jump_entries = section_objs(info, "__jump_table",
					sizeof(*mod->jump_entries),
					&mod->num_jump_entries);
#endif
L
Linus Torvalds 已提交
2918
#ifdef CONFIG_EVENT_TRACING
2919
	mod->trace_events = section_objs(info, "_ftrace_events",
L
Linus Torvalds 已提交
2920 2921
					 sizeof(*mod->trace_events),
					 &mod->num_trace_events);
2922 2923 2924
	mod->trace_enums = section_objs(info, "_ftrace_enum_map",
					sizeof(*mod->trace_enums),
					&mod->num_trace_enums);
L
Linus Torvalds 已提交
2925
#endif
2926 2927 2928 2929 2930
#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
L
Linus Torvalds 已提交
2931 2932
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
	/* sechdrs[0].sh_size is always zero */
2933
	mod->ftrace_callsites = section_objs(info, "__mcount_loc",
L
Linus Torvalds 已提交
2934 2935 2936
					     sizeof(*mod->ftrace_callsites),
					     &mod->num_ftrace_callsites);
#endif
2937

2938 2939 2940
	mod->extable = section_objs(info, "__ex_table",
				    sizeof(*mod->extable), &mod->num_exentries);

2941
	if (section_addr(info, "__obsparm"))
A
Andrew Morton 已提交
2942
		pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2943 2944 2945

	info->debug = section_objs(info, "__verbose",
				   sizeof(*info->debug), &info->num_debug);
2946 2947

	return 0;
L
Linus Torvalds 已提交
2948 2949
}

2950
static int move_module(struct module *mod, struct load_info *info)
2951 2952 2953 2954 2955
{
	int i;
	void *ptr;

	/* Do the allocs. */
2956
	ptr = module_alloc(mod->core_layout.size);
2957 2958 2959 2960 2961 2962 2963
	/*
	 * 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)
R
Rusty Russell 已提交
2964
		return -ENOMEM;
2965

2966 2967
	memset(ptr, 0, mod->core_layout.size);
	mod->core_layout.base = ptr;
2968

2969 2970
	if (mod->init_layout.size) {
		ptr = module_alloc(mod->init_layout.size);
R
Rusty Russell 已提交
2971 2972 2973 2974 2975 2976 2977 2978
		/*
		 * 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) {
2979
			module_memfree(mod->core_layout.base);
R
Rusty Russell 已提交
2980 2981
			return -ENOMEM;
		}
2982 2983
		memset(ptr, 0, mod->init_layout.size);
		mod->init_layout.base = ptr;
R
Rusty Russell 已提交
2984
	} else
2985
		mod->init_layout.base = NULL;
2986 2987

	/* Transfer each section which specifies SHF_ALLOC */
2988
	pr_debug("final section addresses:\n");
2989
	for (i = 0; i < info->hdr->e_shnum; i++) {
2990
		void *dest;
2991
		Elf_Shdr *shdr = &info->sechdrs[i];
2992

2993
		if (!(shdr->sh_flags & SHF_ALLOC))
2994 2995
			continue;

2996
		if (shdr->sh_entsize & INIT_OFFSET_MASK)
2997
			dest = mod->init_layout.base
2998
				+ (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2999
		else
3000
			dest = mod->core_layout.base + shdr->sh_entsize;
3001

3002 3003
		if (shdr->sh_type != SHT_NOBITS)
			memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3004
		/* Update sh_addr to point to copy in image. */
3005
		shdr->sh_addr = (unsigned long)dest;
3006 3007
		pr_debug("\t0x%lx %s\n",
			 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3008
	}
R
Rusty Russell 已提交
3009 3010

	return 0;
3011 3012
}

3013
static int check_module_license_and_versions(struct module *mod)
3014 3015 3016 3017 3018 3019 3020
{
	/*
	 * 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)
3021
		add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3022 3023 3024

	/* driverloader was caught wrongly pretending to be under GPL */
	if (strcmp(mod->name, "driverloader") == 0)
3025 3026
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
3027

3028 3029
	/* lve claims to be GPL but upstream won't provide source */
	if (strcmp(mod->name, "lve") == 0)
3030 3031
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
3032

3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061
#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.
	 */
3062 3063 3064 3065 3066 3067
	if (mod->init_layout.base)
		flush_icache_range((unsigned long)mod->init_layout.base,
				   (unsigned long)mod->init_layout.base
				   + mod->init_layout.size);
	flush_icache_range((unsigned long)mod->core_layout.base,
			   (unsigned long)mod->core_layout.base + mod->core_layout.size);
3068 3069 3070 3071

	set_fs(old_fs);
}

3072 3073 3074 3075 3076 3077 3078 3079
int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
				     Elf_Shdr *sechdrs,
				     char *secstrings,
				     struct module *mod)
{
	return 0;
}

3080
static struct module *layout_and_allocate(struct load_info *info, int flags)
L
Linus Torvalds 已提交
3081
{
R
Rusty Russell 已提交
3082
	/* Module within temporary copy. */
L
Linus Torvalds 已提交
3083
	struct module *mod;
R
Rusty Russell 已提交
3084
	int err;
3085

3086
	mod = setup_load_info(info, flags);
R
Rusty Russell 已提交
3087 3088
	if (IS_ERR(mod))
		return mod;
L
Linus Torvalds 已提交
3089

3090
	err = check_modinfo(mod, info, flags);
3091 3092
	if (err)
		return ERR_PTR(err);
L
Linus Torvalds 已提交
3093 3094

	/* Allow arches to frob section contents and sizes.  */
3095 3096
	err = module_frob_arch_sections(info->hdr, info->sechdrs,
					info->secstrings, mod);
L
Linus Torvalds 已提交
3097
	if (err < 0)
3098
		return ERR_PTR(err);
L
Linus Torvalds 已提交
3099

3100 3101
	/* 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
3102 3103 3104 3105

	/* 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. */
3106 3107
	layout_sections(mod, info);
	layout_symtab(mod, info);
L
Linus Torvalds 已提交
3108

3109
	/* Allocate and move to the final place */
3110
	err = move_module(mod, info);
R
Rusty Russell 已提交
3111
	if (err)
3112
		return ERR_PTR(err);
R
Rusty Russell 已提交
3113 3114 3115

	/* Module has been copied to its final place now: return it. */
	mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3116
	kmemleak_load_module(mod, info);
R
Rusty Russell 已提交
3117 3118 3119 3120 3121 3122 3123
	return mod;
}

/* mod is no longer valid after this! */
static void module_deallocate(struct module *mod, struct load_info *info)
{
	percpu_modfree(mod);
3124
	module_arch_freeing_init(mod);
3125 3126
	module_memfree(mod->init_layout.base);
	module_memfree(mod->core_layout.base);
R
Rusty Russell 已提交
3127 3128
}

3129 3130 3131 3132 3133 3134 3135
int __weak module_finalize(const Elf_Ehdr *hdr,
			   const Elf_Shdr *sechdrs,
			   struct module *me)
{
	return 0;
}

3136 3137
static int post_relocation(struct module *mod, const struct load_info *info)
{
3138
	/* Sort exception table now relocations are done. */
3139 3140 3141 3142 3143 3144
	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);

3145
	/* Setup kallsyms-specific fields. */
3146 3147 3148 3149 3150 3151
	add_kallsyms(mod, info);

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

3152 3153 3154 3155 3156 3157
/* Is this module of this name done loading?  No locks held. */
static bool finished_loading(const char *name)
{
	struct module *mod;
	bool ret;

3158 3159 3160 3161 3162 3163
	/*
	 * 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();
3164
	mutex_lock(&module_mutex);
3165
	mod = find_module_all(name, strlen(name), true);
3166 3167
	ret = !mod || mod->state == MODULE_STATE_LIVE
		|| mod->state == MODULE_STATE_GOING;
3168 3169 3170 3171 3172
	mutex_unlock(&module_mutex);

	return ret;
}

3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183
/* 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
}

3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196
/* 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);
}

3197 3198 3199 3200 3201 3202 3203
/*
 * 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)
3204 3205
{
	int ret = 0;
3206 3207 3208 3209 3210 3211 3212
	struct mod_initfree *freeinit;

	freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
	if (!freeinit) {
		ret = -ENOMEM;
		goto fail;
	}
3213
	freeinit->module_init = mod->init_layout.base;
3214

3215 3216 3217 3218 3219 3220
	/*
	 * 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;

3221 3222 3223 3224 3225
	do_mod_ctors(mod);
	/* Start the module */
	if (mod->init != NULL)
		ret = do_one_initcall(mod->init);
	if (ret < 0) {
3226
		goto fail_free_freeinit;
3227 3228
	}
	if (ret > 0) {
A
Andrew Morton 已提交
3229 3230 3231 3232
		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__);
3233 3234 3235 3236 3237 3238 3239 3240
		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);

3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257
	/*
	 * 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
	 */
3258
	if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3259
		async_synchronize_full();
3260 3261 3262 3263 3264 3265 3266 3267 3268 3269

	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
3270
	mod_tree_remove_init(mod);
R
Rusty Russell 已提交
3271
	disable_ro_nx(&mod->init_layout);
3272
	module_arch_freeing_init(mod);
3273 3274 3275 3276
	mod->init_layout.base = NULL;
	mod->init_layout.size = 0;
	mod->init_layout.ro_size = 0;
	mod->init_layout.text_size = 0;
3277 3278
	/*
	 * We want to free module_init, but be aware that kallsyms may be
3279 3280 3281
	 * 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.
3282
	 */
3283
	call_rcu_sched(&freeinit->rcu, do_free_init);
3284 3285 3286 3287
	mutex_unlock(&module_mutex);
	wake_up_all(&module_wq);

	return 0;
3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300

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;
3301 3302 3303 3304 3305 3306 3307 3308 3309 3310
}

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

	return 0;
}

3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324
/*
 * 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);
3325 3326
	old = find_module_all(mod->name, strlen(mod->name), true);
	if (old != NULL) {
3327 3328 3329 3330
		if (old->state == MODULE_STATE_COMING
		    || old->state == MODULE_STATE_UNFORMED) {
			/* Wait in case it fails to load. */
			mutex_unlock(&module_mutex);
3331 3332
			err = wait_event_interruptible(module_wq,
					       finished_loading(mod->name));
3333 3334 3335 3336 3337 3338 3339
			if (err)
				goto out_unlocked;
			goto again;
		}
		err = -EEXIST;
		goto out;
	}
3340
	mod_update_bounds(mod);
3341
	list_add_rcu(&mod->list, &modules);
3342
	mod_tree_insert(mod);
3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364
	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);

3365
	/* Set RO and NX regions */
R
Rusty Russell 已提交
3366 3367
	module_enable_ro(mod);
	module_enable_nx(mod);
3368

3369 3370 3371
	/* Mark state as coming so strong_try_module_get() ignores us,
	 * but kallsyms etc. can see us. */
	mod->state = MODULE_STATE_COMING;
3372 3373 3374 3375 3376
	mutex_unlock(&module_mutex);

	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_COMING, mod);
	return 0;
3377 3378 3379 3380 3381 3382

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

3383 3384
static int unknown_module_param_cb(char *param, char *val, const char *modname,
				   void *arg)
3385
{
3386 3387 3388 3389 3390 3391 3392 3393
	struct module *mod = arg;
	int ret;

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

3394
	/* Check for magic 'dyndbg' arg */
3395
	ret = ddebug_dyndbg_module_param_cb(param, val, modname);
A
Andrew Morton 已提交
3396 3397
	if (ret != 0)
		pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3398 3399 3400
	return 0;
}

R
Rusty Russell 已提交
3401 3402
/* Allocate and load the module: note that size of section 0 is always
   zero, and we rely on this for optional sections. */
3403 3404
static int load_module(struct load_info *info, const char __user *uargs,
		       int flags)
R
Rusty Russell 已提交
3405
{
3406
	struct module *mod;
R
Rusty Russell 已提交
3407
	long err;
3408
	char *after_dashes;
R
Rusty Russell 已提交
3409

3410 3411 3412
	err = module_sig_check(info);
	if (err)
		goto free_copy;
R
Rusty Russell 已提交
3413

3414
	err = elf_header_check(info);
R
Rusty Russell 已提交
3415
	if (err)
3416
		goto free_copy;
R
Rusty Russell 已提交
3417 3418

	/* Figure out module layout, and allocate all the memory. */
3419
	mod = layout_and_allocate(info, flags);
3420 3421
	if (IS_ERR(mod)) {
		err = PTR_ERR(mod);
R
Rusty Russell 已提交
3422
		goto free_copy;
L
Linus Torvalds 已提交
3423 3424
	}

3425 3426 3427
	/* Reserve our place in the list. */
	err = add_unformed_module(mod);
	if (err)
3428 3429
		goto free_module;

R
Rusty Russell 已提交
3430
#ifdef CONFIG_MODULE_SIG
3431
	mod->sig_ok = info->sig_ok;
3432
	if (!mod->sig_ok) {
A
Andrew Morton 已提交
3433
		pr_notice_once("%s: module verification failed: signature "
3434
			       "and/or required key missing - tainting "
A
Andrew Morton 已提交
3435
			       "kernel\n", mod->name);
3436
		add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3437
	}
R
Rusty Russell 已提交
3438 3439
#endif

3440
	/* To avoid stressing percpu allocator, do this once we're unique. */
R
Rusty Russell 已提交
3441
	err = percpu_modalloc(mod, info);
3442 3443 3444
	if (err)
		goto unlink_mod;

3445
	/* Now module is in final location, initialize linked lists, etc. */
3446 3447
	err = module_unload_init(mod);
	if (err)
3448
		goto unlink_mod;
L
Linus Torvalds 已提交
3449

3450
	init_param_lock(mod);
3451

3452 3453
	/* Now we've got everything in the final locations, we can
	 * find optional sections. */
3454 3455 3456
	err = find_module_sections(mod, info);
	if (err)
		goto free_unload;
3457

3458
	err = check_module_license_and_versions(mod);
3459 3460
	if (err)
		goto free_unload;
3461

3462
	/* Set up MODINFO_ATTR fields */
3463
	setup_modinfo(mod, info);
3464

L
Linus Torvalds 已提交
3465
	/* Fix up syms, so that st_value is a pointer to location. */
3466
	err = simplify_symbols(mod, info);
L
Linus Torvalds 已提交
3467
	if (err < 0)
R
Rusty Russell 已提交
3468
		goto free_modinfo;
L
Linus Torvalds 已提交
3469

3470
	err = apply_relocations(mod, info);
3471
	if (err < 0)
R
Rusty Russell 已提交
3472
		goto free_modinfo;
L
Linus Torvalds 已提交
3473

3474
	err = post_relocation(mod, info);
L
Linus Torvalds 已提交
3475
	if (err < 0)
R
Rusty Russell 已提交
3476
		goto free_modinfo;
L
Linus Torvalds 已提交
3477

3478
	flush_module_icache(mod);
3479

3480 3481 3482 3483 3484 3485
	/* 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;
	}
R
Rusty Russell 已提交
3486

3487
	dynamic_debug_setup(info->debug, info->num_debug);
3488

3489 3490 3491
	/* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
	ftrace_module_init(mod);

3492 3493 3494
	/* Finally it's fully formed, ready to start executing. */
	err = complete_formation(mod, info);
	if (err)
3495
		goto ddebug_cleanup;
3496

3497
	/* Module is ready to execute: parsing args may do that. */
3498
	after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3499 3500
				  -32768, 32767, NULL,
				  unknown_module_param_cb);
3501 3502
	if (IS_ERR(after_dashes)) {
		err = PTR_ERR(after_dashes);
3503
		goto bug_cleanup;
3504 3505 3506 3507
	} else if (after_dashes) {
		pr_warn("%s: parameters '%s' after `--' ignored\n",
		       mod->name, after_dashes);
	}
L
Linus Torvalds 已提交
3508

3509
	/* Link in to syfs. */
3510
	err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
L
Linus Torvalds 已提交
3511
	if (err < 0)
3512
		goto bug_cleanup;
3513

3514
	/* Get rid of temporary copy. */
3515
	free_copy(info);
L
Linus Torvalds 已提交
3516 3517

	/* Done! */
3518
	trace_module_load(mod);
3519 3520

	return do_init_module(mod);
L
Linus Torvalds 已提交
3521

3522 3523
 bug_cleanup:
	/* module_bug_cleanup needs module_mutex protection */
3524
	mutex_lock(&module_mutex);
3525
	module_bug_cleanup(mod);
3526
	mutex_unlock(&module_mutex);
3527

3528 3529 3530
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);

3531
	/* we can't deallocate the module until we clear memory protection */
R
Rusty Russell 已提交
3532 3533
	module_disable_ro(mod);
	module_disable_nx(mod);
3534

3535
 ddebug_cleanup:
3536
	dynamic_debug_remove(info->debug);
3537
	synchronize_sched();
3538 3539
	kfree(mod->args);
 free_arch_cleanup:
L
Linus Torvalds 已提交
3540
	module_arch_cleanup(mod);
R
Rusty Russell 已提交
3541
 free_modinfo:
3542
	free_modinfo(mod);
3543
 free_unload:
L
Linus Torvalds 已提交
3544
	module_unload_free(mod);
3545 3546 3547 3548
 unlink_mod:
	mutex_lock(&module_mutex);
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
3549
	mod_tree_remove(mod);
3550
	wake_up_all(&module_wq);
3551 3552
	/* Wait for RCU-sched synchronizing before releasing mod->list. */
	synchronize_sched();
3553
	mutex_unlock(&module_mutex);
R
Rusty Russell 已提交
3554
 free_module:
3555 3556 3557 3558 3559 3560
	/*
	 * Ftrace needs to clean up what it initialized.
	 * This does nothing if ftrace_module_init() wasn't called,
	 * but it must be called outside of module_mutex.
	 */
	ftrace_release_mod(mod);
3561
	/* Free lock-classes; relies on the preceding sync_rcu() */
3562
	lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3563

3564
	module_deallocate(mod, info);
R
Rusty Russell 已提交
3565
 free_copy:
3566 3567
	free_copy(info);
	return err;
3568 3569
}

3570 3571
SYSCALL_DEFINE3(init_module, void __user *, umod,
		unsigned long, len, const char __user *, uargs)
L
Linus Torvalds 已提交
3572
{
3573 3574
	int err;
	struct load_info info = { };
L
Linus Torvalds 已提交
3575

3576 3577 3578
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3579

3580 3581
	pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
	       umod, len, uargs);
L
Linus Torvalds 已提交
3582

3583 3584 3585
	err = copy_module_from_user(umod, len, &info);
	if (err)
		return err;
L
Linus Torvalds 已提交
3586

3587
	return load_module(&info, uargs, 0);
3588
}
3589

3590
SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3591 3592 3593
{
	int err;
	struct load_info info = { };
3594

3595 3596 3597
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3598

3599
	pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3600

3601 3602 3603
	if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
		      |MODULE_INIT_IGNORE_VERMAGIC))
		return -EINVAL;
3604

3605 3606 3607
	err = copy_module_from_fd(fd, &info);
	if (err)
		return err;
L
Linus Torvalds 已提交
3608

3609
	return load_module(&info, uargs, flags);
L
Linus Torvalds 已提交
3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623
}

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 $d.
 */
static inline int is_arm_mapping_symbol(const char *str)
{
3624 3625
	if (str[0] == '.' && str[1] == 'L')
		return true;
K
Kyle McMartin 已提交
3626
	return str[0] == '$' && strchr("axtd", str[1])
L
Linus Torvalds 已提交
3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638
	       && (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 */
3639
	if (within_module_init(addr, mod))
3640
		nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
D
Daniel Walker 已提交
3641
	else
3642
		nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
L
Linus Torvalds 已提交
3643

L
Lucas De Marchi 已提交
3644
	/* Scan for closest preceding symbol, and next symbol. (ELF
D
Daniel Walker 已提交
3645
	   starts real symbols at 1). */
L
Linus Torvalds 已提交
3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666
	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;

A
Alexey Dobriyan 已提交
3667 3668 3669 3670
	if (size)
		*size = nextval - mod->symtab[best].st_value;
	if (offset)
		*offset = addr - mod->symtab[best].st_value;
L
Linus Torvalds 已提交
3671 3672 3673
	return mod->strtab + mod->symtab[best].st_name;
}

3674 3675
/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3676
const char *module_address_lookup(unsigned long addr,
3677 3678 3679 3680
			    unsigned long *size,
			    unsigned long *offset,
			    char **modname,
			    char *namebuf)
L
Linus Torvalds 已提交
3681
{
3682
	const char *ret = NULL;
3683
	struct module *mod;
L
Linus Torvalds 已提交
3684

3685
	preempt_disable();
3686 3687 3688 3689 3690
	mod = __module_address(addr);
	if (mod) {
		if (modname)
			*modname = mod->name;
		ret = get_ksymbol(mod, addr, size, offset);
L
Linus Torvalds 已提交
3691
	}
3692 3693 3694 3695 3696
	/* Make a copy in here where it's safe */
	if (ret) {
		strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
		ret = namebuf;
	}
3697
	preempt_enable();
3698

3699
	return ret;
L
Linus Torvalds 已提交
3700 3701
}

3702 3703 3704 3705
int lookup_module_symbol_name(unsigned long addr, char *symname)
{
	struct module *mod;

3706
	preempt_disable();
3707
	list_for_each_entry_rcu(mod, &modules, list) {
3708 3709
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3710
		if (within_module(addr, mod)) {
3711 3712 3713 3714 3715
			const char *sym;

			sym = get_ksymbol(mod, addr, NULL, NULL);
			if (!sym)
				goto out;
3716
			strlcpy(symname, sym, KSYM_NAME_LEN);
3717
			preempt_enable();
3718 3719 3720 3721
			return 0;
		}
	}
out:
3722
	preempt_enable();
3723 3724 3725
	return -ERANGE;
}

3726 3727 3728 3729 3730
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
			unsigned long *offset, char *modname, char *name)
{
	struct module *mod;

3731
	preempt_disable();
3732
	list_for_each_entry_rcu(mod, &modules, list) {
3733 3734
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3735
		if (within_module(addr, mod)) {
3736 3737 3738 3739 3740 3741
			const char *sym;

			sym = get_ksymbol(mod, addr, size, offset);
			if (!sym)
				goto out;
			if (modname)
3742
				strlcpy(modname, mod->name, MODULE_NAME_LEN);
3743
			if (name)
3744
				strlcpy(name, sym, KSYM_NAME_LEN);
3745
			preempt_enable();
3746 3747 3748 3749
			return 0;
		}
	}
out:
3750
	preempt_enable();
3751 3752 3753
	return -ERANGE;
}

3754 3755
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
3756 3757 3758
{
	struct module *mod;

3759
	preempt_disable();
3760
	list_for_each_entry_rcu(mod, &modules, list) {
3761 3762
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
L
Linus Torvalds 已提交
3763 3764 3765
		if (symnum < mod->num_symtab) {
			*value = mod->symtab[symnum].st_value;
			*type = mod->symtab[symnum].st_info;
3766
			strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3767 3768
				KSYM_NAME_LEN);
			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3769
			*exported = is_exported(name, *value, mod);
3770
			preempt_enable();
3771
			return 0;
L
Linus Torvalds 已提交
3772 3773 3774
		}
		symnum -= mod->num_symtab;
	}
3775
	preempt_enable();
3776
	return -ERANGE;
L
Linus Torvalds 已提交
3777 3778 3779 3780 3781 3782 3783
}

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

	for (i = 0; i < mod->num_symtab; i++)
3784 3785
		if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
		    mod->symtab[i].st_info != 'U')
L
Linus Torvalds 已提交
3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797
			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. */
3798
	preempt_disable();
L
Linus Torvalds 已提交
3799
	if ((colon = strchr(name, ':')) != NULL) {
3800
		if ((mod = find_module_all(name, colon - name, false)) != NULL)
L
Linus Torvalds 已提交
3801 3802
			ret = mod_find_symname(mod, colon+1);
	} else {
3803 3804 3805
		list_for_each_entry_rcu(mod, &modules, list) {
			if (mod->state == MODULE_STATE_UNFORMED)
				continue;
L
Linus Torvalds 已提交
3806 3807
			if ((ret = mod_find_symname(mod, name)) != 0)
				break;
3808
		}
L
Linus Torvalds 已提交
3809
	}
3810
	preempt_enable();
L
Linus Torvalds 已提交
3811 3812
	return ret;
}
3813 3814 3815 3816 3817 3818 3819 3820 3821

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;

3822 3823
	module_assert_mutex();

3824
	list_for_each_entry(mod, &modules, list) {
3825 3826
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3827 3828 3829 3830 3831 3832 3833 3834 3835
		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
3836 3837
#endif /* CONFIG_KALLSYMS */

3838
static char *module_flags(struct module *mod, char *buf)
3839 3840 3841
{
	int bx = 0;

3842
	BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3843 3844 3845
	if (mod->taints ||
	    mod->state == MODULE_STATE_GOING ||
	    mod->state == MODULE_STATE_COMING) {
3846
		buf[bx++] = '(';
3847
		bx += module_flags_taint(mod, buf + bx);
3848 3849 3850 3851 3852 3853
		/* 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++] = '+';
3854 3855 3856 3857 3858 3859 3860
		buf[bx++] = ')';
	}
	buf[bx] = '\0';

	return buf;
}

3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878
#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);
}

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static int m_show(struct seq_file *m, void *p)
{
	struct module *mod = list_entry(p, struct module, list);
3882 3883
	char buf[8];

3884 3885 3886 3887
	/* We always ignore unformed modules. */
	if (mod->state == MODULE_STATE_UNFORMED)
		return 0;

3888
	seq_printf(m, "%s %u",
3889
		   mod->name, mod->init_layout.size + mod->core_layout.size);
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	print_unload_info(m, mod);

	/* Informative for users. */
	seq_printf(m, " %s",
3894 3895
		   mod->state == MODULE_STATE_GOING ? "Unloading" :
		   mod->state == MODULE_STATE_COMING ? "Loading" :
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		   "Live");
	/* Used by oprofile and other similar tools. */
3898
	seq_printf(m, " 0x%pK", mod->core_layout.base);
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3900 3901
	/* Taints info */
	if (mod->taints)
3902
		seq_printf(m, " %s", module_flags(mod, buf));
3903

3904
	seq_puts(m, "\n");
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	return 0;
}

/* Format: modulename size refcount deps address

   Where refcount is a number or -, and deps is a comma-separated list
   of depends or -.
*/
3913
static const struct seq_operations modules_op = {
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	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= m_show
};

3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 3930 3931 3932 3933 3934 3935 3936 3937 3938 3939
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

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/* 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;

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	preempt_disable();
3947
	list_for_each_entry_rcu(mod, &modules, list) {
3948 3949
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
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		if (mod->num_exentries == 0)
			continue;
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		e = search_extable(mod->extable,
				   mod->extable + mod->num_exentries - 1,
				   addr);
		if (e)
			break;
	}
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	preempt_enable();
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	/* Now, if we found one, we are running inside it now, hence
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	   we cannot unload the module, hence no refcnt needed. */
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	return e;
}

3966
/*
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 * 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).
3972
 */
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bool is_module_address(unsigned long addr)
3974
{
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	bool ret;
3976

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	preempt_disable();
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	ret = __module_address(addr) != NULL;
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	preempt_enable();
3980

R
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	return ret;
3982 3983
}

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/*
 * __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.
 */
3991
struct module *__module_address(unsigned long addr)
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{
	struct module *mod;

3995 3996 3997
	if (addr < module_addr_min || addr > module_addr_max)
		return NULL;

3998 3999
	module_assert_mutex_or_preempt();

4000
	mod = mod_find(addr);
4001 4002
	if (mod) {
		BUG_ON(!within_module(addr, mod));
4003
		if (mod->state == MODULE_STATE_UNFORMED)
4004
			mod = NULL;
4005
	}
4006
	return mod;
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}
4008
EXPORT_SYMBOL_GPL(__module_address);
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/*
 * 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. */
4041 4042
		if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
		    && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
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			mod = NULL;
	}
	return mod;
}
4047
EXPORT_SYMBOL_GPL(__module_text_address);
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/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
	struct module *mod;
4053
	char buf[8];
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4055
	printk(KERN_DEFAULT "Modules linked in:");
4056 4057
	/* Most callers should already have preempt disabled, but make sure */
	preempt_disable();
4058 4059 4060
	list_for_each_entry_rcu(mod, &modules, list) {
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
J
Jiri Slaby 已提交
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		pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4062
	}
4063
	preempt_enable();
4064
	if (last_unloaded_module[0])
J
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		pr_cont(" [last unloaded: %s]", last_unloaded_module);
	pr_cont("\n");
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}

#ifdef CONFIG_MODVERSIONS
4070 4071 4072 4073 4074 4075
/* 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,
4076
		   struct tracepoint * const *tp)
4077 4078 4079
{
}
EXPORT_SYMBOL(module_layout);
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#endif