module.c 111.4 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/extable.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 <linux/uaccess.h>
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#include <asm/cacheflush.h>
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#include <linux/set_memory.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/livepatch.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 <linux/dynamic_debug.h>
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#include <linux/audit.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
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 * only when CONFIG_STRICT_MODULE_RWX=y
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 */
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#ifdef CONFIG_STRICT_MODULE_RWX
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# 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;

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

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static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
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module_param(sig_enforce, bool_enable_only, 0644);
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/*
 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
 */
bool is_module_sig_enforced(void)
{
	return sig_enforce;
}
EXPORT_SYMBOL(is_module_sig_enforced);

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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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/*
 * We require a truly strong try_module_get(): 0 means success.
 * Otherwise an error is returned 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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	set_bit(flag, &mod->taints);
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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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 */
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void __noreturn __module_put_and_exit(struct module *mod, long code)
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{
	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 s32 __start___kcrctab[];
extern const s32 __start___kcrctab_gpl[];
extern const s32 __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 s32 __start___kcrctab_unused[];
extern const s32 __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;
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	const s32 *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,
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					const s32 **crc,
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					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_rcu(mod, &modules, list) {
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		if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
			continue;
597
		if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
L
Linus Torvalds 已提交
598 599 600 601
			return mod;
	}
	return NULL;
}
602 603 604

struct module *find_module(const char *name)
{
605
	module_assert_mutex();
606
	return find_module_all(name, strlen(name), false);
607
}
608
EXPORT_SYMBOL_GPL(find_module);
L
Linus Torvalds 已提交
609 610

#ifdef CONFIG_SMP
611

612
static inline void __percpu *mod_percpu(struct module *mod)
613
{
614 615
	return mod->percpu;
}
616

R
Rusty Russell 已提交
617
static int percpu_modalloc(struct module *mod, struct load_info *info)
618
{
R
Rusty Russell 已提交
619 620 621 622 623 624
	Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
	unsigned long align = pcpusec->sh_addralign;

	if (!pcpusec->sh_size)
		return 0;

625
	if (align > PAGE_SIZE) {
A
Andrew Morton 已提交
626 627
		pr_warn("%s: per-cpu alignment %li > %li\n",
			mod->name, align, PAGE_SIZE);
628 629 630
		align = PAGE_SIZE;
	}

R
Rusty Russell 已提交
631
	mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
632
	if (!mod->percpu) {
A
Andrew Morton 已提交
633 634
		pr_warn("%s: Could not allocate %lu bytes percpu data\n",
			mod->name, (unsigned long)pcpusec->sh_size);
635 636
		return -ENOMEM;
	}
R
Rusty Russell 已提交
637
	mod->percpu_size = pcpusec->sh_size;
638
	return 0;
639 640
}

641
static void percpu_modfree(struct module *mod)
642
{
643
	free_percpu(mod->percpu);
644 645
}

646
static unsigned int find_pcpusec(struct load_info *info)
647
{
648
	return find_sec(info, ".data..percpu");
649 650
}

651 652
static void percpu_modcopy(struct module *mod,
			   const void *from, unsigned long size)
653 654 655 656
{
	int cpu;

	for_each_possible_cpu(cpu)
657
		memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
658 659
}

660
bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
661 662 663 664 665 666 667
{
	struct module *mod;
	unsigned int cpu;

	preempt_disable();

	list_for_each_entry_rcu(mod, &modules, list) {
668 669
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
670 671 672 673
		if (!mod->percpu_size)
			continue;
		for_each_possible_cpu(cpu) {
			void *start = per_cpu_ptr(mod->percpu, cpu);
674
			void *va = (void *)addr;
675

676
			if (va >= start && va < start + mod->percpu_size) {
677
				if (can_addr) {
678
					*can_addr = (unsigned long) (va - start);
679 680 681 682
					*can_addr += (unsigned long)
						per_cpu_ptr(mod->percpu,
							    get_boot_cpu_id());
				}
683 684 685 686 687 688 689 690
				preempt_enable();
				return true;
			}
		}
	}

	preempt_enable();
	return false;
691 692
}

693 694 695 696 697 698 699 700 701 702 703 704 705 706
/**
 * 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)
{
	return __is_module_percpu_address(addr, NULL);
}

L
Linus Torvalds 已提交
707
#else /* ... !CONFIG_SMP */
708

709
static inline void __percpu *mod_percpu(struct module *mod)
L
Linus Torvalds 已提交
710 711 712
{
	return NULL;
}
R
Rusty Russell 已提交
713
static int percpu_modalloc(struct module *mod, struct load_info *info)
714
{
R
Rusty Russell 已提交
715 716 717 718
	/* 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;
719 720
}
static inline void percpu_modfree(struct module *mod)
L
Linus Torvalds 已提交
721 722
{
}
723
static unsigned int find_pcpusec(struct load_info *info)
L
Linus Torvalds 已提交
724 725 726
{
	return 0;
}
727 728
static inline void percpu_modcopy(struct module *mod,
				  const void *from, unsigned long size)
L
Linus Torvalds 已提交
729 730 731 732
{
	/* pcpusec should be 0, and size of that section should be 0. */
	BUG_ON(size != 0);
}
733 734 735 736
bool is_module_percpu_address(unsigned long addr)
{
	return false;
}
737

738 739 740 741 742
bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
{
	return false;
}

L
Linus Torvalds 已提交
743 744
#endif /* CONFIG_SMP */

745 746 747 748 749 750
#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,   \
751
			struct module_kobject *mk, char *buffer)      \
752
{                                                                     \
753
	return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field);  \
754 755 756 757 758 759 760
}                                                                     \
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
761 762
	kfree(mod->field);                                            \
	mod->field = NULL;                                            \
763 764
}                                                                     \
static struct module_attribute modinfo_##field = {                    \
765
	.attr = { .name = __stringify(field), .mode = 0444 },         \
766 767 768 769 770 771 772 773 774
	.show = show_modinfo_##field,                                 \
	.setup = setup_modinfo_##field,                               \
	.test = modinfo_##field##_exists,                             \
	.free = free_modinfo_##field,                                 \
};

MODINFO_ATTR(version);
MODINFO_ATTR(srcversion);

775 776
static char last_unloaded_module[MODULE_NAME_LEN+1];

777
#ifdef CONFIG_MODULE_UNLOAD
778 779 780

EXPORT_TRACEPOINT_SYMBOL(module_get);

781 782 783
/* MODULE_REF_BASE is the base reference count by kmodule loader. */
#define MODULE_REF_BASE	1

L
Linus Torvalds 已提交
784
/* Init the unload section of the module. */
785
static int module_unload_init(struct module *mod)
L
Linus Torvalds 已提交
786
{
787 788 789 790 791
	/*
	 * Initialize reference counter to MODULE_REF_BASE.
	 * refcnt == 0 means module is going.
	 */
	atomic_set(&mod->refcnt, MODULE_REF_BASE);
792

793 794
	INIT_LIST_HEAD(&mod->source_list);
	INIT_LIST_HEAD(&mod->target_list);
795

L
Linus Torvalds 已提交
796
	/* Hold reference count during initialization. */
797
	atomic_inc(&mod->refcnt);
798 799

	return 0;
L
Linus Torvalds 已提交
800 801 802 803 804 805 806
}

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

807 808
	list_for_each_entry(use, &b->source_list, source_list) {
		if (use->source == a) {
809
			pr_debug("%s uses %s!\n", a->name, b->name);
L
Linus Torvalds 已提交
810 811 812
			return 1;
		}
	}
813
	pr_debug("%s does not use %s!\n", a->name, b->name);
L
Linus Torvalds 已提交
814 815 816
	return 0;
}

817 818 819 820 821 822 823 824 825 826 827
/*
 * 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;

828
	pr_debug("Allocating new usage for %s.\n", a->name);
829
	use = kmalloc(sizeof(*use), GFP_ATOMIC);
830
	if (!use)
831 832 833 834 835 836 837 838 839
		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;
}

840
/* Module a uses b: caller needs module_mutex() */
841
int ref_module(struct module *a, struct module *b)
L
Linus Torvalds 已提交
842
{
843
	int err;
K
Kay Sievers 已提交
844

845
	if (b == NULL || already_uses(a, b))
846 847
		return 0;

848 849
	/* If module isn't available, we fail. */
	err = strong_try_module_get(b);
850
	if (err)
851
		return err;
L
Linus Torvalds 已提交
852

853 854
	err = add_module_usage(a, b);
	if (err) {
L
Linus Torvalds 已提交
855
		module_put(b);
856
		return err;
L
Linus Torvalds 已提交
857
	}
858
	return 0;
L
Linus Torvalds 已提交
859
}
860
EXPORT_SYMBOL_GPL(ref_module);
L
Linus Torvalds 已提交
861 862 863 864

/* Clear the unload stuff of the module. */
static void module_unload_free(struct module *mod)
{
865
	struct module_use *use, *tmp;
L
Linus Torvalds 已提交
866

867
	mutex_lock(&module_mutex);
868 869
	list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
		struct module *i = use->target;
870
		pr_debug("%s unusing %s\n", mod->name, i->name);
871 872 873 874
		module_put(i);
		list_del(&use->source_list);
		list_del(&use->target_list);
		kfree(use);
L
Linus Torvalds 已提交
875
	}
876
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
877 878 879
}

#ifdef CONFIG_MODULE_FORCE_UNLOAD
880
static inline int try_force_unload(unsigned int flags)
L
Linus Torvalds 已提交
881 882 883
{
	int ret = (flags & O_TRUNC);
	if (ret)
884
		add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
L
Linus Torvalds 已提交
885 886 887
	return ret;
}
#else
888
static inline int try_force_unload(unsigned int flags)
L
Linus Torvalds 已提交
889 890 891 892 893
{
	return 0;
}
#endif /* CONFIG_MODULE_FORCE_UNLOAD */

894 895
/* Try to release refcount of module, 0 means success. */
static int try_release_module_ref(struct module *mod)
L
Linus Torvalds 已提交
896
{
897
	int ret;
L
Linus Torvalds 已提交
898

899 900 901 902 903 904
	/* 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
905

906 907
	return ret;
}
L
Linus Torvalds 已提交
908

909 910
static int try_stop_module(struct module *mod, int flags, int *forced)
{
911
	/* If it's not unused, quit unless we're forcing. */
912 913 914
	if (try_release_module_ref(mod) != 0) {
		*forced = try_force_unload(flags);
		if (!(*forced))
L
Linus Torvalds 已提交
915 916 917 918
			return -EWOULDBLOCK;
	}

	/* Mark it as dying. */
919
	mod->state = MODULE_STATE_GOING;
L
Linus Torvalds 已提交
920

921
	return 0;
L
Linus Torvalds 已提交
922 923
}

924 925 926 927 928 929 930 931 932 933
/**
 * 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
934
{
935
	return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
L
Linus Torvalds 已提交
936 937 938 939 940 941
}
EXPORT_SYMBOL(module_refcount);

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

942 943
SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
		unsigned int, flags)
L
Linus Torvalds 已提交
944 945
{
	struct module *mod;
946
	char name[MODULE_NAME_LEN];
L
Linus Torvalds 已提交
947 948
	int ret, forced = 0;

949
	if (!capable(CAP_SYS_MODULE) || modules_disabled)
950 951 952 953 954 955
		return -EPERM;

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

956 957
	audit_log_kern_module(name);

958 959
	if (mutex_lock_interruptible(&module_mutex) != 0)
		return -EINTR;
L
Linus Torvalds 已提交
960 961 962 963 964 965 966

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

967
	if (!list_empty(&mod->source_list)) {
L
Linus Torvalds 已提交
968 969 970 971 972 973 974
		/* 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) {
975
		/* FIXME: if (force), slam module count damn the torpedoes */
976
		pr_debug("%s already dying\n", mod->name);
L
Linus Torvalds 已提交
977 978 979 980 981
		ret = -EBUSY;
		goto out;
	}

	/* If it has an init func, it must have an exit func to unload */
R
Rusty Russell 已提交
982
	if (mod->init && !mod->exit) {
983
		forced = try_force_unload(flags);
L
Linus Torvalds 已提交
984 985 986 987 988 989 990 991 992 993 994 995
		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;

996
	mutex_unlock(&module_mutex);
L
Lucas De Marchi 已提交
997
	/* Final destruction now no one is using it. */
998
	if (mod->exit != NULL)
L
Linus Torvalds 已提交
999
		mod->exit();
1000 1001
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
1002
	klp_module_going(mod);
1003 1004
	ftrace_release_mod(mod);

1005
	async_synchronize_full();
1006

1007
	/* Store the name of the last unloaded module for diagnostic purposes */
1008
	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
L
Linus Torvalds 已提交
1009

1010 1011 1012
	free_module(mod);
	return 0;
out:
1013
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
1014 1015 1016
	return ret;
}

1017
static inline void print_unload_info(struct seq_file *m, struct module *mod)
L
Linus Torvalds 已提交
1018 1019 1020 1021
{
	struct module_use *use;
	int printed_something = 0;

1022
	seq_printf(m, " %i ", module_refcount(mod));
L
Linus Torvalds 已提交
1023

1024 1025 1026 1027
	/*
	 * Always include a trailing , so userspace can differentiate
	 * between this and the old multi-field proc format.
	 */
1028
	list_for_each_entry(use, &mod->source_list, source_list) {
L
Linus Torvalds 已提交
1029
		printed_something = 1;
1030
		seq_printf(m, "%s,", use->source->name);
L
Linus Torvalds 已提交
1031 1032 1033 1034
	}

	if (mod->init != NULL && mod->exit == NULL) {
		printed_something = 1;
1035
		seq_puts(m, "[permanent],");
L
Linus Torvalds 已提交
1036 1037 1038
	}

	if (!printed_something)
1039
		seq_puts(m, "-");
L
Linus Torvalds 已提交
1040 1041 1042 1043 1044 1045
}

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

R
Rusty Russell 已提交
1046
	preempt_disable();
1047
	if (!find_symbol(symbol, &owner, NULL, true, false))
L
Linus Torvalds 已提交
1048 1049
		BUG();
	module_put(owner);
R
Rusty Russell 已提交
1050
	preempt_enable();
L
Linus Torvalds 已提交
1051 1052 1053
}
EXPORT_SYMBOL(__symbol_put);

1054
/* Note this assumes addr is a function, which it currently always is. */
L
Linus Torvalds 已提交
1055 1056
void symbol_put_addr(void *addr)
{
1057
	struct module *modaddr;
1058
	unsigned long a = (unsigned long)dereference_function_descriptor(addr);
L
Linus Torvalds 已提交
1059

1060
	if (core_kernel_text(a))
1061
		return;
L
Linus Torvalds 已提交
1062

1063 1064 1065 1066 1067
	/*
	 * 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();
1068
	modaddr = __module_text_address(a);
1069
	BUG_ON(!modaddr);
1070
	module_put(modaddr);
1071
	preempt_enable();
L
Linus Torvalds 已提交
1072 1073 1074 1075
}
EXPORT_SYMBOL_GPL(symbol_put_addr);

static ssize_t show_refcnt(struct module_attribute *mattr,
1076
			   struct module_kobject *mk, char *buffer)
L
Linus Torvalds 已提交
1077
{
1078
	return sprintf(buffer, "%i\n", module_refcount(mk->mod));
L
Linus Torvalds 已提交
1079 1080
}

1081 1082
static struct module_attribute modinfo_refcnt =
	__ATTR(refcnt, 0444, show_refcnt, NULL);
L
Linus Torvalds 已提交
1083

1084 1085 1086 1087
void __module_get(struct module *module)
{
	if (module) {
		preempt_disable();
1088
		atomic_inc(&module->refcnt);
1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100
		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();
1101 1102 1103
		/* Note: here, we can fail to get a reference */
		if (likely(module_is_live(module) &&
			   atomic_inc_not_zero(&module->refcnt) != 0))
1104
			trace_module_get(module, _RET_IP_);
1105
		else
1106 1107 1108 1109 1110 1111 1112 1113
			ret = false;

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

A
Al Viro 已提交
1114 1115
void module_put(struct module *module)
{
1116 1117
	int ret;

A
Al Viro 已提交
1118
	if (module) {
1119
		preempt_disable();
1120 1121
		ret = atomic_dec_if_positive(&module->refcnt);
		WARN_ON(ret < 0);	/* Failed to put refcount */
1122
		trace_module_put(module, _RET_IP_);
1123
		preempt_enable();
A
Al Viro 已提交
1124 1125 1126 1127
	}
}
EXPORT_SYMBOL(module_put);

L
Linus Torvalds 已提交
1128
#else /* !CONFIG_MODULE_UNLOAD */
1129
static inline void print_unload_info(struct seq_file *m, struct module *mod)
L
Linus Torvalds 已提交
1130 1131
{
	/* We don't know the usage count, or what modules are using. */
1132
	seq_puts(m, " - -");
L
Linus Torvalds 已提交
1133 1134 1135 1136 1137 1138
}

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

1139
int ref_module(struct module *a, struct module *b)
L
Linus Torvalds 已提交
1140
{
1141
	return strong_try_module_get(b);
L
Linus Torvalds 已提交
1142
}
1143
EXPORT_SYMBOL_GPL(ref_module);
L
Linus Torvalds 已提交
1144

1145
static inline int module_unload_init(struct module *mod)
L
Linus Torvalds 已提交
1146
{
1147
	return 0;
L
Linus Torvalds 已提交
1148 1149 1150
}
#endif /* CONFIG_MODULE_UNLOAD */

1151 1152 1153
static size_t module_flags_taint(struct module *mod, char *buf)
{
	size_t l = 0;
1154 1155 1156 1157
	int i;

	for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
		if (taint_flags[i].module && test_bit(i, &mod->taints))
1158
			buf[l++] = taint_flags[i].c_true;
1159
	}
1160 1161 1162 1163

	return l;
}

1164
static ssize_t show_initstate(struct module_attribute *mattr,
1165
			      struct module_kobject *mk, char *buffer)
1166 1167 1168
{
	const char *state = "unknown";

1169
	switch (mk->mod->state) {
1170 1171 1172 1173 1174 1175 1176 1177 1178
	case MODULE_STATE_LIVE:
		state = "live";
		break;
	case MODULE_STATE_COMING:
		state = "coming";
		break;
	case MODULE_STATE_GOING:
		state = "going";
		break;
1179 1180
	default:
		BUG();
1181 1182 1183 1184
	}
	return sprintf(buffer, "%s\n", state);
}

1185 1186
static struct module_attribute modinfo_initstate =
	__ATTR(initstate, 0444, show_initstate, NULL);
1187

1188 1189 1190 1191
static ssize_t store_uevent(struct module_attribute *mattr,
			    struct module_kobject *mk,
			    const char *buffer, size_t count)
{
1192
	kobject_synth_uevent(&mk->kobj, buffer, count);
1193 1194 1195
	return count;
}

1196 1197 1198 1199 1200 1201
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)
{
1202
	return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1203 1204 1205 1206 1207 1208 1209 1210
}

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)
{
1211
	return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228
}

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);
1229

1230
static struct module_attribute *modinfo_attrs[] = {
1231
	&module_uevent,
1232 1233
	&modinfo_version,
	&modinfo_srcversion,
1234 1235 1236 1237
	&modinfo_initstate,
	&modinfo_coresize,
	&modinfo_initsize,
	&modinfo_taint,
1238
#ifdef CONFIG_MODULE_UNLOAD
1239
	&modinfo_refcnt,
1240 1241 1242 1243
#endif
	NULL,
};

L
Linus Torvalds 已提交
1244 1245
static const char vermagic[] = VERMAGIC_STRING;

1246
static int try_to_force_load(struct module *mod, const char *reason)
1247 1248
{
#ifdef CONFIG_MODULE_FORCE_LOAD
A
Andi Kleen 已提交
1249
	if (!test_taint(TAINT_FORCED_MODULE))
A
Andrew Morton 已提交
1250
		pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1251
	add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1252 1253 1254 1255 1256 1257
	return 0;
#else
	return -ENOEXEC;
#endif
}

L
Linus Torvalds 已提交
1258
#ifdef CONFIG_MODVERSIONS
1259 1260

static u32 resolve_rel_crc(const s32 *crc)
1261
{
1262
	return *(u32 *)((void *)crc + *crc);
1263 1264
}

1265
static int check_version(const struct load_info *info,
L
Linus Torvalds 已提交
1266
			 const char *symname,
1267
			 struct module *mod,
1268
			 const s32 *crc)
L
Linus Torvalds 已提交
1269
{
1270 1271
	Elf_Shdr *sechdrs = info->sechdrs;
	unsigned int versindex = info->index.vers;
L
Linus Torvalds 已提交
1272 1273 1274 1275 1276 1277 1278
	unsigned int i, num_versions;
	struct modversion_info *versions;

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

1279 1280 1281 1282
	/* 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
1283 1284 1285 1286 1287
	versions = (void *) sechdrs[versindex].sh_addr;
	num_versions = sechdrs[versindex].sh_size
		/ sizeof(struct modversion_info);

	for (i = 0; i < num_versions; i++) {
1288 1289
		u32 crcval;

L
Linus Torvalds 已提交
1290 1291 1292
		if (strcmp(versions[i].name, symname) != 0)
			continue;

1293 1294 1295 1296 1297
		if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
			crcval = resolve_rel_crc(crc);
		else
			crcval = *crc;
		if (versions[i].crc == crcval)
L
Linus Torvalds 已提交
1298
			return 1;
1299 1300
		pr_debug("Found checksum %X vs module %lX\n",
			 crcval, versions[i].crc);
1301
		goto bad_version;
L
Linus Torvalds 已提交
1302
	}
1303

1304
	/* Broken toolchain. Warn once, then let it go.. */
K
Kees Cook 已提交
1305
	pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1306
	return 1;
1307 1308

bad_version:
1309
	pr_warn("%s: disagrees about version of symbol %s\n",
K
Kees Cook 已提交
1310
	       info->name, symname);
1311
	return 0;
L
Linus Torvalds 已提交
1312 1313
}

1314
static inline int check_modstruct_version(const struct load_info *info,
L
Linus Torvalds 已提交
1315 1316
					  struct module *mod)
{
1317
	const s32 *crc;
L
Linus Torvalds 已提交
1318

1319 1320 1321 1322 1323
	/*
	 * Since this should be found in kernel (which can't be removed), no
	 * locking is necessary -- use preempt_disable() to placate lockdep.
	 */
	preempt_disable();
1324
	if (!find_symbol("module_layout", NULL, &crc, true, false)) {
1325
		preempt_enable();
L
Linus Torvalds 已提交
1326
		BUG();
1327 1328
	}
	preempt_enable();
1329
	return check_version(info, "module_layout", mod, crc);
L
Linus Torvalds 已提交
1330 1331
}

1332 1333 1334
/* 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
1335
{
1336 1337 1338 1339
	if (has_crcs) {
		amagic += strcspn(amagic, " ");
		bmagic += strcspn(bmagic, " ");
	}
L
Linus Torvalds 已提交
1340 1341 1342
	return strcmp(amagic, bmagic) == 0;
}
#else
1343
static inline int check_version(const struct load_info *info,
L
Linus Torvalds 已提交
1344
				const char *symname,
1345
				struct module *mod,
1346
				const s32 *crc)
L
Linus Torvalds 已提交
1347 1348 1349 1350
{
	return 1;
}

1351
static inline int check_modstruct_version(const struct load_info *info,
L
Linus Torvalds 已提交
1352 1353 1354 1355 1356
					  struct module *mod)
{
	return 1;
}

1357 1358
static inline int same_magic(const char *amagic, const char *bmagic,
			     bool has_crcs)
L
Linus Torvalds 已提交
1359 1360 1361 1362 1363
{
	return strcmp(amagic, bmagic) == 0;
}
#endif /* CONFIG_MODVERSIONS */

1364
/* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1365 1366
static const struct kernel_symbol *resolve_symbol(struct module *mod,
						  const struct load_info *info,
1367
						  const char *name,
1368
						  char ownername[])
L
Linus Torvalds 已提交
1369 1370
{
	struct module *owner;
1371
	const struct kernel_symbol *sym;
1372
	const s32 *crc;
1373
	int err;
L
Linus Torvalds 已提交
1374

1375 1376 1377 1378 1379 1380
	/*
	 * 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();
1381
	mutex_lock(&module_mutex);
1382
	sym = find_symbol(name, &owner, &crc,
A
Andi Kleen 已提交
1383
			  !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1384 1385 1386
	if (!sym)
		goto unlock;

1387
	if (!check_version(info, name, mod, crc)) {
1388 1389
		sym = ERR_PTR(-EINVAL);
		goto getname;
L
Linus Torvalds 已提交
1390
	}
1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401

	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:
1402
	mutex_unlock(&module_mutex);
1403
	return sym;
L
Linus Torvalds 已提交
1404 1405
}

1406 1407 1408 1409
static const struct kernel_symbol *
resolve_symbol_wait(struct module *mod,
		    const struct load_info *info,
		    const char *name)
1410 1411
{
	const struct kernel_symbol *ksym;
1412
	char owner[MODULE_NAME_LEN];
1413 1414

	if (wait_event_interruptible_timeout(module_wq,
1415 1416
			!IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
			|| PTR_ERR(ksym) != -EBUSY,
1417
					     30 * HZ) <= 0) {
A
Andrew Morton 已提交
1418 1419
		pr_warn("%s: gave up waiting for init of module %s.\n",
			mod->name, owner);
1420 1421 1422 1423
	}
	return ksym;
}

L
Linus Torvalds 已提交
1424 1425 1426 1427
/*
 * /sys/module/foo/sections stuff
 * J. Corbet <corbet@lwn.net>
 */
R
Rusty Russell 已提交
1428
#ifdef CONFIG_SYSFS
1429

R
Rusty Russell 已提交
1430
#ifdef CONFIG_KALLSYMS
1431 1432 1433 1434 1435
static inline bool sect_empty(const Elf_Shdr *sect)
{
	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
}

1436
struct module_sect_attr {
1437 1438 1439 1440 1441
	struct module_attribute mattr;
	char *name;
	unsigned long address;
};

1442
struct module_sect_attrs {
1443 1444 1445 1446 1447
	struct attribute_group grp;
	unsigned int nsections;
	struct module_sect_attr attrs[0];
};

L
Linus Torvalds 已提交
1448
static ssize_t module_sect_show(struct module_attribute *mattr,
1449
				struct module_kobject *mk, char *buf)
L
Linus Torvalds 已提交
1450 1451 1452
{
	struct module_sect_attr *sattr =
		container_of(mattr, struct module_sect_attr, mattr);
1453 1454
	return sprintf(buf, "0x%px\n", kptr_restrict < 2 ?
		       (void *)sattr->address : NULL);
L
Linus Torvalds 已提交
1455 1456
}

1457 1458
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
1459
	unsigned int section;
1460 1461 1462 1463 1464 1465

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

R
Rusty Russell 已提交
1466
static void add_sect_attrs(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
1467 1468 1469 1470 1471
{
	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
1472

L
Linus Torvalds 已提交
1473
	/* Count loaded sections and allocate structures */
R
Rusty Russell 已提交
1474 1475
	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]))
L
Linus Torvalds 已提交
1476 1477 1478 1479 1480
			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]);
1481 1482
	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
	if (sect_attrs == NULL)
L
Linus Torvalds 已提交
1483 1484 1485 1486 1487 1488
		return;

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

1489
	sect_attrs->nsections = 0;
L
Linus Torvalds 已提交
1490 1491
	sattr = &sect_attrs->attrs[0];
	gattr = &sect_attrs->grp.attrs[0];
R
Rusty Russell 已提交
1492 1493 1494
	for (i = 0; i < info->hdr->e_shnum; i++) {
		Elf_Shdr *sec = &info->sechdrs[i];
		if (sect_empty(sec))
1495
			continue;
R
Rusty Russell 已提交
1496 1497
		sattr->address = sec->sh_addr;
		sattr->name = kstrdup(info->secstrings + sec->sh_name,
1498 1499 1500 1501
					GFP_KERNEL);
		if (sattr->name == NULL)
			goto out;
		sect_attrs->nsections++;
1502
		sysfs_attr_init(&sattr->mattr.attr);
L
Linus Torvalds 已提交
1503 1504 1505
		sattr->mattr.show = module_sect_show;
		sattr->mattr.store = NULL;
		sattr->mattr.attr.name = sattr->name;
1506
		sattr->mattr.attr.mode = S_IRUSR;
L
Linus Torvalds 已提交
1507 1508 1509 1510 1511 1512 1513 1514 1515 1516
		*(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:
1517
	free_sect_attrs(sect_attrs);
L
Linus Torvalds 已提交
1518 1519 1520 1521 1522 1523 1524 1525 1526
}

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. */
1527
		free_sect_attrs(mod->sect_attrs);
L
Linus Torvalds 已提交
1528 1529 1530 1531
		mod->sect_attrs = NULL;
	}
}

R
Roland McGrath 已提交
1532 1533 1534 1535 1536 1537 1538 1539 1540 1541
/*
 * /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];
};

1542
static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
R
Roland McGrath 已提交
1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559
				 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]);
1560
		kobject_put(notes_attrs->dir);
R
Roland McGrath 已提交
1561 1562 1563 1564
	}
	kfree(notes_attrs);
}

R
Rusty Russell 已提交
1565
static void add_notes_attrs(struct module *mod, const struct load_info *info)
R
Roland McGrath 已提交
1566 1567 1568 1569 1570
{
	unsigned int notes, loaded, i;
	struct module_notes_attrs *notes_attrs;
	struct bin_attribute *nattr;

1571 1572 1573 1574
	/* failed to create section attributes, so can't create notes */
	if (!mod->sect_attrs)
		return;

R
Roland McGrath 已提交
1575 1576
	/* Count notes sections and allocate structures.  */
	notes = 0;
R
Rusty Russell 已提交
1577 1578 1579
	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
1580 1581 1582 1583 1584
			++notes;

	if (notes == 0)
		return;

1585
	notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
R
Roland McGrath 已提交
1586 1587 1588 1589 1590 1591
			      GFP_KERNEL);
	if (notes_attrs == NULL)
		return;

	notes_attrs->notes = notes;
	nattr = &notes_attrs->attrs[0];
R
Rusty Russell 已提交
1592 1593
	for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
		if (sect_empty(&info->sechdrs[i]))
R
Roland McGrath 已提交
1594
			continue;
R
Rusty Russell 已提交
1595
		if (info->sechdrs[i].sh_type == SHT_NOTE) {
1596
			sysfs_bin_attr_init(nattr);
R
Roland McGrath 已提交
1597 1598
			nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
			nattr->attr.mode = S_IRUGO;
R
Rusty Russell 已提交
1599 1600
			nattr->size = info->sechdrs[i].sh_size;
			nattr->private = (void *) info->sechdrs[i].sh_addr;
R
Roland McGrath 已提交
1601 1602 1603 1604 1605 1606
			nattr->read = module_notes_read;
			++nattr;
		}
		++loaded;
	}

1607
	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
R
Roland McGrath 已提交
1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628
	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
1629
#else
1630

R
Rusty Russell 已提交
1631 1632
static inline void add_sect_attrs(struct module *mod,
				  const struct load_info *info)
L
Linus Torvalds 已提交
1633 1634 1635 1636 1637 1638
{
}

static inline void remove_sect_attrs(struct module *mod)
{
}
R
Roland McGrath 已提交
1639

R
Rusty Russell 已提交
1640 1641
static inline void add_notes_attrs(struct module *mod,
				   const struct load_info *info)
R
Roland McGrath 已提交
1642 1643 1644 1645 1646 1647
{
}

static inline void remove_notes_attrs(struct module *mod)
{
}
R
Rusty Russell 已提交
1648
#endif /* CONFIG_KALLSYMS */
L
Linus Torvalds 已提交
1649

1650
static void del_usage_links(struct module *mod)
1651 1652 1653 1654
{
#ifdef CONFIG_MODULE_UNLOAD
	struct module_use *use;

1655
	mutex_lock(&module_mutex);
1656 1657
	list_for_each_entry(use, &mod->target_list, target_list)
		sysfs_remove_link(use->target->holders_dir, mod->name);
1658
	mutex_unlock(&module_mutex);
1659 1660 1661
#endif
}

1662
static int add_usage_links(struct module *mod)
1663
{
1664
	int ret = 0;
1665 1666 1667
#ifdef CONFIG_MODULE_UNLOAD
	struct module_use *use;

1668
	mutex_lock(&module_mutex);
1669 1670 1671 1672 1673 1674
	list_for_each_entry(use, &mod->target_list, target_list) {
		ret = sysfs_create_link(use->target->holders_dir,
					&mod->mkobj.kobj, mod->name);
		if (ret)
			break;
	}
1675
	mutex_unlock(&module_mutex);
1676 1677
	if (ret)
		del_usage_links(mod);
1678
#endif
1679
	return ret;
1680 1681
}

1682
static int module_add_modinfo_attrs(struct module *mod)
1683 1684
{
	struct module_attribute *attr;
1685
	struct module_attribute *temp_attr;
1686 1687 1688
	int error = 0;
	int i;

1689 1690 1691 1692 1693 1694 1695
	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;
1696
	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
R
Rusty Russell 已提交
1697
		if (!attr->test || attr->test(mod)) {
1698
			memcpy(temp_attr, attr, sizeof(*temp_attr));
1699
			sysfs_attr_init(&temp_attr->attr);
1700 1701
			error = sysfs_create_file(&mod->mkobj.kobj,
					&temp_attr->attr);
1702 1703
			++temp_attr;
		}
1704 1705 1706 1707
	}
	return error;
}

1708
static void module_remove_modinfo_attrs(struct module *mod)
1709 1710 1711 1712
{
	struct module_attribute *attr;
	int i;

1713 1714 1715 1716
	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
		/* pick a field to test for end of list */
		if (!attr->attr.name)
			break;
1717
		sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1718 1719
		if (attr->free)
			attr->free(mod);
1720
	}
1721
	kfree(mod->modinfo_attrs);
1722
}
L
Linus Torvalds 已提交
1723

1724 1725 1726 1727 1728 1729 1730 1731
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);
}

1732
static int mod_sysfs_init(struct module *mod)
L
Linus Torvalds 已提交
1733 1734
{
	int err;
1735
	struct kobject *kobj;
L
Linus Torvalds 已提交
1736

1737
	if (!module_sysfs_initialized) {
A
Andrew Morton 已提交
1738
		pr_err("%s: module sysfs not initialized\n", mod->name);
1739 1740 1741
		err = -EINVAL;
		goto out;
	}
1742 1743 1744

	kobj = kset_find_obj(module_kset, mod->name);
	if (kobj) {
A
Andrew Morton 已提交
1745
		pr_err("%s: module is already loaded\n", mod->name);
1746 1747 1748 1749 1750
		kobject_put(kobj);
		err = -EINVAL;
		goto out;
	}

L
Linus Torvalds 已提交
1751
	mod->mkobj.mod = mod;
1752

1753 1754 1755 1756 1757
	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)
1758
		mod_kobject_put(mod);
K
Kay Sievers 已提交
1759

1760
	/* delay uevent until full sysfs population */
K
Kay Sievers 已提交
1761 1762 1763 1764
out:
	return err;
}

1765
static int mod_sysfs_setup(struct module *mod,
R
Rusty Russell 已提交
1766
			   const struct load_info *info,
K
Kay Sievers 已提交
1767 1768 1769 1770 1771
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	int err;

1772 1773 1774 1775
	err = mod_sysfs_init(mod);
	if (err)
		goto out;

1776
	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1777 1778
	if (!mod->holders_dir) {
		err = -ENOMEM;
K
Kay Sievers 已提交
1779
		goto out_unreg;
1780
	}
K
Kay Sievers 已提交
1781

L
Linus Torvalds 已提交
1782 1783
	err = module_param_sysfs_setup(mod, kparam, num_params);
	if (err)
K
Kay Sievers 已提交
1784
		goto out_unreg_holders;
L
Linus Torvalds 已提交
1785

1786 1787
	err = module_add_modinfo_attrs(mod);
	if (err)
1788
		goto out_unreg_param;
1789

1790 1791 1792 1793
	err = add_usage_links(mod);
	if (err)
		goto out_unreg_modinfo_attrs;

R
Rusty Russell 已提交
1794 1795
	add_sect_attrs(mod, info);
	add_notes_attrs(mod, info);
1796

1797
	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
L
Linus Torvalds 已提交
1798 1799
	return 0;

1800 1801
out_unreg_modinfo_attrs:
	module_remove_modinfo_attrs(mod);
1802 1803
out_unreg_param:
	module_param_sysfs_remove(mod);
K
Kay Sievers 已提交
1804
out_unreg_holders:
1805
	kobject_put(mod->holders_dir);
K
Kay Sievers 已提交
1806
out_unreg:
1807
	mod_kobject_put(mod);
1808
out:
L
Linus Torvalds 已提交
1809 1810
	return err;
}
1811 1812 1813

static void mod_sysfs_fini(struct module *mod)
{
R
Rusty Russell 已提交
1814 1815
	remove_notes_attrs(mod);
	remove_sect_attrs(mod);
1816
	mod_kobject_put(mod);
1817 1818
}

1819 1820 1821 1822
static void init_param_lock(struct module *mod)
{
	mutex_init(&mod->param_lock);
}
R
Rusty Russell 已提交
1823
#else /* !CONFIG_SYSFS */
1824

R
Rusty Russell 已提交
1825 1826
static int mod_sysfs_setup(struct module *mod,
			   const struct load_info *info,
1827 1828 1829 1830 1831 1832
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	return 0;
}

1833 1834 1835 1836
static void mod_sysfs_fini(struct module *mod)
{
}

1837 1838 1839 1840
static void module_remove_modinfo_attrs(struct module *mod)
{
}

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

1845 1846 1847
static void init_param_lock(struct module *mod)
{
}
1848
#endif /* CONFIG_SYSFS */
L
Linus Torvalds 已提交
1849

1850
static void mod_sysfs_teardown(struct module *mod)
L
Linus Torvalds 已提交
1851
{
1852
	del_usage_links(mod);
1853
	module_remove_modinfo_attrs(mod);
L
Linus Torvalds 已提交
1854
	module_param_sysfs_remove(mod);
1855 1856
	kobject_put(mod->mkobj.drivers_dir);
	kobject_put(mod->holders_dir);
1857
	mod_sysfs_fini(mod);
L
Linus Torvalds 已提交
1858 1859
}

1860
#ifdef CONFIG_STRICT_MODULE_RWX
1861 1862 1863
/*
 * LKM RO/NX protection: protect module's text/ro-data
 * from modification and any data from execution.
R
Rusty Russell 已提交
1864 1865
 *
 * General layout of module is:
J
Jessica Yu 已提交
1866 1867 1868 1869 1870
 *          [text] [read-only-data] [ro-after-init] [writable data]
 * text_size -----^                ^               ^               ^
 * ro_size ------------------------|               |               |
 * ro_after_init_size -----------------------------|               |
 * size -----------------------------------------------------------|
R
Rusty Russell 已提交
1871 1872
 *
 * These values are always page-aligned (as is base)
1873
 */
R
Rusty Russell 已提交
1874 1875
static void frob_text(const struct module_layout *layout,
		      int (*set_memory)(unsigned long start, int num_pages))
1876
{
R
Rusty Russell 已提交
1877 1878 1879 1880
	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);
1881 1882
}

R
Rusty Russell 已提交
1883 1884
static void frob_rodata(const struct module_layout *layout,
			int (*set_memory)(unsigned long start, int num_pages))
1885
{
R
Rusty Russell 已提交
1886 1887 1888 1889 1890
	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);
1891 1892
}

J
Jessica Yu 已提交
1893 1894 1895 1896 1897 1898 1899 1900 1901 1902
static void frob_ro_after_init(const struct module_layout *layout,
				int (*set_memory)(unsigned long start, int num_pages))
{
	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
	BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
	BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
	set_memory((unsigned long)layout->base + layout->ro_size,
		   (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
}

R
Rusty Russell 已提交
1903 1904
static void frob_writable_data(const struct module_layout *layout,
			       int (*set_memory)(unsigned long start, int num_pages))
1905
{
R
Rusty Russell 已提交
1906
	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
J
Jessica Yu 已提交
1907
	BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
R
Rusty Russell 已提交
1908
	BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
J
Jessica Yu 已提交
1909 1910
	set_memory((unsigned long)layout->base + layout->ro_after_init_size,
		   (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1911 1912
}

R
Rusty Russell 已提交
1913 1914
/* livepatching wants to disable read-only so it can frob module. */
void module_disable_ro(const struct module *mod)
1915
{
1916 1917 1918
	if (!rodata_enabled)
		return;

R
Rusty Russell 已提交
1919 1920
	frob_text(&mod->core_layout, set_memory_rw);
	frob_rodata(&mod->core_layout, set_memory_rw);
J
Jessica Yu 已提交
1921
	frob_ro_after_init(&mod->core_layout, set_memory_rw);
R
Rusty Russell 已提交
1922 1923
	frob_text(&mod->init_layout, set_memory_rw);
	frob_rodata(&mod->init_layout, set_memory_rw);
1924
}
1925

J
Jessica Yu 已提交
1926
void module_enable_ro(const struct module *mod, bool after_init)
1927
{
1928 1929 1930
	if (!rodata_enabled)
		return;

R
Rusty Russell 已提交
1931 1932 1933 1934
	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);
J
Jessica Yu 已提交
1935 1936 1937

	if (after_init)
		frob_ro_after_init(&mod->core_layout, set_memory_ro);
1938 1939
}

R
Rusty Russell 已提交
1940
static void module_enable_nx(const struct module *mod)
1941
{
R
Rusty Russell 已提交
1942
	frob_rodata(&mod->core_layout, set_memory_nx);
J
Jessica Yu 已提交
1943
	frob_ro_after_init(&mod->core_layout, set_memory_nx);
R
Rusty Russell 已提交
1944 1945 1946
	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);
1947 1948
}

R
Rusty Russell 已提交
1949
static void module_disable_nx(const struct module *mod)
1950
{
R
Rusty Russell 已提交
1951
	frob_rodata(&mod->core_layout, set_memory_x);
J
Jessica Yu 已提交
1952
	frob_ro_after_init(&mod->core_layout, set_memory_x);
R
Rusty Russell 已提交
1953 1954 1955
	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);
1956 1957 1958
}

/* Iterate through all modules and set each module's text as RW */
1959
void set_all_modules_text_rw(void)
1960 1961 1962
{
	struct module *mod;

1963 1964 1965
	if (!rodata_enabled)
		return;

1966 1967
	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1968 1969
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
R
Rusty Russell 已提交
1970 1971 1972

		frob_text(&mod->core_layout, set_memory_rw);
		frob_text(&mod->init_layout, set_memory_rw);
1973 1974 1975 1976 1977
	}
	mutex_unlock(&module_mutex);
}

/* Iterate through all modules and set each module's text as RO */
1978
void set_all_modules_text_ro(void)
1979 1980 1981
{
	struct module *mod;

1982 1983 1984
	if (!rodata_enabled)
		return;

1985 1986
	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1987 1988 1989 1990 1991 1992 1993
		/*
		 * Ignore going modules since it's possible that ro
		 * protection has already been disabled, otherwise we'll
		 * run into protection faults at module deallocation.
		 */
		if (mod->state == MODULE_STATE_UNFORMED ||
			mod->state == MODULE_STATE_GOING)
1994
			continue;
R
Rusty Russell 已提交
1995 1996 1997

		frob_text(&mod->core_layout, set_memory_ro);
		frob_text(&mod->init_layout, set_memory_ro);
1998 1999 2000
	}
	mutex_unlock(&module_mutex);
}
R
Rusty Russell 已提交
2001 2002 2003

static void disable_ro_nx(const struct module_layout *layout)
{
2004 2005 2006 2007 2008
	if (rodata_enabled) {
		frob_text(layout, set_memory_rw);
		frob_rodata(layout, set_memory_rw);
		frob_ro_after_init(layout, set_memory_rw);
	}
R
Rusty Russell 已提交
2009
	frob_rodata(layout, set_memory_x);
J
Jessica Yu 已提交
2010
	frob_ro_after_init(layout, set_memory_x);
R
Rusty Russell 已提交
2011 2012 2013
	frob_writable_data(layout, set_memory_x);
}

2014
#else
R
Rusty Russell 已提交
2015 2016 2017
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) { }
2018 2019
#endif

2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041
#ifdef CONFIG_LIVEPATCH
/*
 * Persist Elf information about a module. Copy the Elf header,
 * section header table, section string table, and symtab section
 * index from info to mod->klp_info.
 */
static int copy_module_elf(struct module *mod, struct load_info *info)
{
	unsigned int size, symndx;
	int ret;

	size = sizeof(*mod->klp_info);
	mod->klp_info = kmalloc(size, GFP_KERNEL);
	if (mod->klp_info == NULL)
		return -ENOMEM;

	/* Elf header */
	size = sizeof(mod->klp_info->hdr);
	memcpy(&mod->klp_info->hdr, info->hdr, size);

	/* Elf section header table */
	size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2042
	mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2043 2044 2045 2046 2047 2048 2049
	if (mod->klp_info->sechdrs == NULL) {
		ret = -ENOMEM;
		goto free_info;
	}

	/* Elf section name string table */
	size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2050
	mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094
	if (mod->klp_info->secstrings == NULL) {
		ret = -ENOMEM;
		goto free_sechdrs;
	}

	/* Elf symbol section index */
	symndx = info->index.sym;
	mod->klp_info->symndx = symndx;

	/*
	 * For livepatch modules, core_kallsyms.symtab is a complete
	 * copy of the original symbol table. Adjust sh_addr to point
	 * to core_kallsyms.symtab since the copy of the symtab in module
	 * init memory is freed at the end of do_init_module().
	 */
	mod->klp_info->sechdrs[symndx].sh_addr = \
		(unsigned long) mod->core_kallsyms.symtab;

	return 0;

free_sechdrs:
	kfree(mod->klp_info->sechdrs);
free_info:
	kfree(mod->klp_info);
	return ret;
}

static void free_module_elf(struct module *mod)
{
	kfree(mod->klp_info->sechdrs);
	kfree(mod->klp_info->secstrings);
	kfree(mod->klp_info);
}
#else /* !CONFIG_LIVEPATCH */
static int copy_module_elf(struct module *mod, struct load_info *info)
{
	return 0;
}

static void free_module_elf(struct module *mod)
{
}
#endif /* CONFIG_LIVEPATCH */

2095
void __weak module_memfree(void *module_region)
2096 2097 2098 2099 2100 2101 2102 2103
{
	vfree(module_region);
}

void __weak module_arch_cleanup(struct module *mod)
{
}

2104 2105 2106 2107
void __weak module_arch_freeing_init(struct module *mod)
{
}

2108
/* Free a module, remove from lists, etc. */
L
Linus Torvalds 已提交
2109 2110
static void free_module(struct module *mod)
{
2111 2112
	trace_module_free(mod);

2113
	mod_sysfs_teardown(mod);
L
Linus Torvalds 已提交
2114

2115 2116
	/* We leave it in list to prevent duplicate loads, but make sure
	 * that noone uses it while it's being deconstructed. */
2117
	mutex_lock(&module_mutex);
2118
	mod->state = MODULE_STATE_UNFORMED;
2119
	mutex_unlock(&module_mutex);
2120

2121 2122 2123
	/* Remove dynamic debug info */
	ddebug_remove_module(mod->name);

L
Linus Torvalds 已提交
2124 2125 2126 2127 2128 2129
	/* Arch-specific cleanup. */
	module_arch_cleanup(mod);

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

2130 2131 2132
	/* Free any allocated parameters. */
	destroy_params(mod->kp, mod->num_kp);

2133 2134 2135
	if (is_livepatch_module(mod))
		free_module_elf(mod);

2136 2137
	/* Now we can delete it from the lists */
	mutex_lock(&module_mutex);
2138 2139
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
2140
	mod_tree_remove(mod);
2141
	/* Remove this module from bug list, this uses list_del_rcu */
2142
	module_bug_cleanup(mod);
2143 2144
	/* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
	synchronize_sched();
2145 2146
	mutex_unlock(&module_mutex);

R
Rusty Russell 已提交
2147 2148
	/* This may be empty, but that's OK */
	disable_ro_nx(&mod->init_layout);
2149
	module_arch_freeing_init(mod);
2150
	module_memfree(mod->init_layout.base);
L
Linus Torvalds 已提交
2151
	kfree(mod->args);
2152
	percpu_modfree(mod);
2153

2154
	/* Free lock-classes; relies on the preceding sync_rcu(). */
2155
	lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
I
Ingo Molnar 已提交
2156

L
Linus Torvalds 已提交
2157
	/* Finally, free the core (containing the module structure) */
R
Rusty Russell 已提交
2158
	disable_ro_nx(&mod->core_layout);
2159
	module_memfree(mod->core_layout.base);
L
Linus Torvalds 已提交
2160 2161 2162 2163 2164
}

void *__symbol_get(const char *symbol)
{
	struct module *owner;
2165
	const struct kernel_symbol *sym;
L
Linus Torvalds 已提交
2166

R
Rusty Russell 已提交
2167
	preempt_disable();
2168 2169 2170
	sym = find_symbol(symbol, &owner, NULL, true, true);
	if (sym && strong_try_module_get(owner))
		sym = NULL;
R
Rusty Russell 已提交
2171
	preempt_enable();
L
Linus Torvalds 已提交
2172

2173
	return sym ? (void *)sym->value : NULL;
L
Linus Torvalds 已提交
2174 2175 2176
}
EXPORT_SYMBOL_GPL(__symbol_get);

2177 2178
/*
 * Ensure that an exported symbol [global namespace] does not already exist
2179
 * in the kernel or in some other module's exported symbol table.
2180 2181
 *
 * You must hold the module_mutex.
2182 2183 2184
 */
static int verify_export_symbols(struct module *mod)
{
2185
	unsigned int i;
2186
	struct module *owner;
2187 2188 2189 2190 2191 2192 2193 2194
	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 },
2195
#ifdef CONFIG_UNUSED_SYMBOLS
2196 2197
		{ mod->unused_syms, mod->num_unused_syms },
		{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2198
#endif
2199
	};
2200

2201 2202
	for (i = 0; i < ARRAY_SIZE(arr); i++) {
		for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2203
			if (find_symbol(s->name, &owner, NULL, true, false)) {
A
Andrew Morton 已提交
2204
				pr_err("%s: exports duplicate symbol %s"
2205 2206 2207 2208
				       " (owned by %s)\n",
				       mod->name, s->name, module_name(owner));
				return -ENOEXEC;
			}
2209
		}
2210 2211
	}
	return 0;
2212 2213
}

2214
/* Change all symbols so that st_value encodes the pointer directly. */
2215 2216 2217 2218
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
2219
	unsigned long secbase;
2220
	unsigned int i;
L
Linus Torvalds 已提交
2221
	int ret = 0;
2222
	const struct kernel_symbol *ksym;
L
Linus Torvalds 已提交
2223

2224 2225 2226
	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
2227 2228
		switch (sym[i].st_shndx) {
		case SHN_COMMON:
2229 2230 2231 2232
			/* Ignore common symbols */
			if (!strncmp(name, "__gnu_lto", 9))
				break;

L
Linus Torvalds 已提交
2233 2234
			/* We compiled with -fno-common.  These are not
			   supposed to happen.  */
2235
			pr_debug("Common symbol: %s\n", name);
2236
			pr_warn("%s: please compile with -fno-common\n",
L
Linus Torvalds 已提交
2237 2238 2239 2240 2241 2242
			       mod->name);
			ret = -ENOEXEC;
			break;

		case SHN_ABS:
			/* Don't need to do anything */
2243
			pr_debug("Absolute symbol: 0x%08lx\n",
L
Linus Torvalds 已提交
2244 2245 2246
			       (long)sym[i].st_value);
			break;

2247 2248 2249 2250
		case SHN_LIVEPATCH:
			/* Livepatch symbols are resolved by livepatch */
			break;

L
Linus Torvalds 已提交
2251
		case SHN_UNDEF:
2252
			ksym = resolve_symbol_wait(mod, info, name);
L
Linus Torvalds 已提交
2253
			/* Ok if resolved.  */
2254
			if (ksym && !IS_ERR(ksym)) {
2255
				sym[i].st_value = ksym->value;
L
Linus Torvalds 已提交
2256
				break;
2257 2258
			}

L
Linus Torvalds 已提交
2259
			/* Ok if weak.  */
2260
			if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
L
Linus Torvalds 已提交
2261 2262
				break;

2263
			ret = PTR_ERR(ksym) ?: -ENOENT;
2264 2265
			pr_warn("%s: Unknown symbol %s (err %d)\n",
				mod->name, name, ret);
L
Linus Torvalds 已提交
2266 2267 2268 2269
			break;

		default:
			/* Divert to percpu allocation if a percpu var. */
2270
			if (sym[i].st_shndx == info->index.pcpu)
2271
				secbase = (unsigned long)mod_percpu(mod);
L
Linus Torvalds 已提交
2272
			else
2273
				secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
L
Linus Torvalds 已提交
2274 2275 2276 2277 2278 2279 2280 2281
			sym[i].st_value += secbase;
			break;
		}
	}

	return ret;
}

2282
static int apply_relocations(struct module *mod, const struct load_info *info)
2283 2284 2285 2286 2287
{
	unsigned int i;
	int err = 0;

	/* Now do relocations. */
2288 2289
	for (i = 1; i < info->hdr->e_shnum; i++) {
		unsigned int infosec = info->sechdrs[i].sh_info;
2290 2291

		/* Not a valid relocation section? */
2292
		if (infosec >= info->hdr->e_shnum)
2293 2294 2295
			continue;

		/* Don't bother with non-allocated sections */
2296
		if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2297 2298
			continue;

2299 2300 2301 2302
		/* Livepatch relocation sections are applied by livepatch */
		if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
			continue;

2303 2304 2305 2306 2307 2308
		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);
2309 2310 2311 2312 2313 2314
		if (err < 0)
			break;
	}
	return err;
}

2315 2316 2317 2318 2319 2320 2321 2322
/* 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
2323
/* Update size with this section: return offset. */
2324 2325
static long get_offset(struct module *mod, unsigned int *size,
		       Elf_Shdr *sechdr, unsigned int section)
L
Linus Torvalds 已提交
2326 2327 2328
{
	long ret;

2329
	*size += arch_mod_section_prepend(mod, section);
L
Linus Torvalds 已提交
2330 2331 2332 2333 2334 2335 2336 2337 2338
	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. */
2339
static void layout_sections(struct module *mod, struct load_info *info)
L
Linus Torvalds 已提交
2340 2341 2342 2343 2344 2345 2346
{
	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 },
J
Jessica Yu 已提交
2347
		{ SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
L
Linus Torvalds 已提交
2348 2349 2350 2351 2352
		{ SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
		{ ARCH_SHF_SMALL | SHF_ALLOC, 0 }
	};
	unsigned int m, i;

2353 2354
	for (i = 0; i < info->hdr->e_shnum; i++)
		info->sechdrs[i].sh_entsize = ~0UL;
L
Linus Torvalds 已提交
2355

2356
	pr_debug("Core section allocation order:\n");
L
Linus Torvalds 已提交
2357
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2358 2359 2360
		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
2361 2362 2363 2364

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2365
			    || strstarts(sname, ".init"))
L
Linus Torvalds 已提交
2366
				continue;
2367
			s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2368
			pr_debug("\t%s\n", sname);
L
Linus Torvalds 已提交
2369
		}
2370 2371
		switch (m) {
		case 0: /* executable */
2372 2373
			mod->core_layout.size = debug_align(mod->core_layout.size);
			mod->core_layout.text_size = mod->core_layout.size;
2374 2375
			break;
		case 1: /* RO: text and ro-data */
2376 2377
			mod->core_layout.size = debug_align(mod->core_layout.size);
			mod->core_layout.ro_size = mod->core_layout.size;
2378
			break;
J
Jessica Yu 已提交
2379 2380 2381 2382 2383
		case 2: /* RO after init */
			mod->core_layout.size = debug_align(mod->core_layout.size);
			mod->core_layout.ro_after_init_size = mod->core_layout.size;
			break;
		case 4: /* whole core */
2384
			mod->core_layout.size = debug_align(mod->core_layout.size);
2385 2386
			break;
		}
L
Linus Torvalds 已提交
2387 2388
	}

2389
	pr_debug("Init section allocation order:\n");
L
Linus Torvalds 已提交
2390
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2391 2392 2393
		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
2394 2395 2396 2397

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2398
			    || !strstarts(sname, ".init"))
L
Linus Torvalds 已提交
2399
				continue;
2400
			s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
L
Linus Torvalds 已提交
2401
					 | INIT_OFFSET_MASK);
2402
			pr_debug("\t%s\n", sname);
L
Linus Torvalds 已提交
2403
		}
2404 2405
		switch (m) {
		case 0: /* executable */
2406 2407
			mod->init_layout.size = debug_align(mod->init_layout.size);
			mod->init_layout.text_size = mod->init_layout.size;
2408 2409
			break;
		case 1: /* RO: text and ro-data */
2410 2411
			mod->init_layout.size = debug_align(mod->init_layout.size);
			mod->init_layout.ro_size = mod->init_layout.size;
2412
			break;
J
Jessica Yu 已提交
2413 2414 2415 2416 2417 2418 2419 2420
		case 2:
			/*
			 * RO after init doesn't apply to init_layout (only
			 * core_layout), so it just takes the value of ro_size.
			 */
			mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
			break;
		case 4: /* whole init */
2421
			mod->init_layout.size = debug_align(mod->init_layout.size);
2422 2423
			break;
		}
L
Linus Torvalds 已提交
2424 2425 2426 2427 2428 2429 2430 2431
	}
}

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

2432
	if (!license_is_gpl_compatible(license)) {
A
Andi Kleen 已提交
2433
		if (!test_taint(TAINT_PROPRIETARY_MODULE))
A
Andrew Morton 已提交
2434 2435
			pr_warn("%s: module license '%s' taints kernel.\n",
				mod->name, license);
2436 2437
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
L
Linus Torvalds 已提交
2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459
	}
}

/* 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;
}

2460
static char *get_modinfo(struct load_info *info, const char *tag)
L
Linus Torvalds 已提交
2461 2462 2463
{
	char *p;
	unsigned int taglen = strlen(tag);
2464 2465
	Elf_Shdr *infosec = &info->sechdrs[info->index.info];
	unsigned long size = infosec->sh_size;
L
Linus Torvalds 已提交
2466

2467 2468 2469 2470 2471
	/*
	 * get_modinfo() calls made before rewrite_section_headers()
	 * must use sh_offset, as sh_addr isn't set!
	 */
	for (p = (char *)info->hdr + infosec->sh_offset; p; p = next_string(p, &size)) {
L
Linus Torvalds 已提交
2472 2473 2474 2475 2476 2477
		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
			return p + taglen + 1;
	}
	return NULL;
}

2478
static void setup_modinfo(struct module *mod, struct load_info *info)
2479 2480 2481 2482 2483 2484
{
	struct module_attribute *attr;
	int i;

	for (i = 0; (attr = modinfo_attrs[i]); i++) {
		if (attr->setup)
2485
			attr->setup(mod, get_modinfo(info, attr->attr.name));
2486 2487 2488
	}
}

2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499
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
2500
#ifdef CONFIG_KALLSYMS
2501 2502 2503 2504 2505 2506

/* 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)
{
2507 2508
	return bsearch(name, start, stop - start,
			sizeof(struct kernel_symbol), cmp_name);
2509 2510
}

2511 2512
static int is_exported(const char *name, unsigned long value,
		       const struct module *mod)
L
Linus Torvalds 已提交
2513
{
2514 2515 2516
	const struct kernel_symbol *ks;
	if (!mod)
		ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2517
	else
2518 2519
		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
	return ks != NULL && ks->value == value;
L
Linus Torvalds 已提交
2520 2521 2522
}

/* As per nm */
2523
static char elf_type(const Elf_Sym *sym, const struct load_info *info)
L
Linus Torvalds 已提交
2524
{
2525 2526
	const Elf_Shdr *sechdrs = info->sechdrs;

L
Linus Torvalds 已提交
2527 2528 2529 2530 2531 2532 2533 2534
	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';
2535
	if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
L
Linus Torvalds 已提交
2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555
		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';
	}
2556 2557
	if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
		      ".debug")) {
L
Linus Torvalds 已提交
2558
		return 'n';
2559
	}
L
Linus Torvalds 已提交
2560 2561 2562
	return '?';
}

2563
static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2564
			unsigned int shnum, unsigned int pcpundx)
2565 2566 2567 2568 2569 2570 2571 2572
{
	const Elf_Shdr *sec;

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

2573 2574 2575 2576 2577
#ifdef CONFIG_KALLSYMS_ALL
	if (src->st_shndx == pcpundx)
		return true;
#endif

2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588
	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;
}

2589 2590 2591 2592 2593 2594 2595
/*
 * 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>.
 */
2596
static void layout_symtab(struct module *mod, struct load_info *info)
2597
{
2598 2599
	Elf_Shdr *symsect = info->sechdrs + info->index.sym;
	Elf_Shdr *strsect = info->sechdrs + info->index.str;
2600
	const Elf_Sym *src;
2601
	unsigned int i, nsrc, ndst, strtab_size = 0;
2602 2603 2604

	/* Put symbol section at end of init part of module. */
	symsect->sh_flags |= SHF_ALLOC;
2605
	symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2606
					 info->index.sym) | INIT_OFFSET_MASK;
2607
	pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2608

2609
	src = (void *)info->hdr + symsect->sh_offset;
2610
	nsrc = symsect->sh_size / sizeof(*src);
2611

2612
	/* Compute total space required for the core symbols' strtab. */
2613
	for (ndst = i = 0; i < nsrc; i++) {
2614
		if (i == 0 || is_livepatch_module(mod) ||
2615 2616
		    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
				   info->index.pcpu)) {
2617
			strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2618
			ndst++;
2619
		}
2620
	}
2621 2622

	/* Append room for core symbols at end of core part. */
2623 2624 2625 2626
	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);
2627

2628 2629
	/* Put string table section at end of init part of module. */
	strsect->sh_flags |= SHF_ALLOC;
2630
	strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2631
					 info->index.str) | INIT_OFFSET_MASK;
2632
	pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2633 2634 2635 2636 2637 2638 2639

	/* We'll tack temporary mod_kallsyms on the end. */
	mod->init_layout.size = ALIGN(mod->init_layout.size,
				      __alignof__(struct mod_kallsyms));
	info->mod_kallsyms_init_off = mod->init_layout.size;
	mod->init_layout.size += sizeof(struct mod_kallsyms);
	mod->init_layout.size = debug_align(mod->init_layout.size);
2640 2641
}

2642 2643 2644 2645 2646
/*
 * We use the full symtab and strtab which layout_symtab arranged to
 * be appended to the init section.  Later we switch to the cut-down
 * core-only ones.
 */
2647
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2648
{
2649 2650 2651
	unsigned int i, ndst;
	const Elf_Sym *src;
	Elf_Sym *dst;
2652
	char *s;
2653
	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
L
Linus Torvalds 已提交
2654

2655 2656 2657 2658 2659
	/* Set up to point into init section. */
	mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;

	mod->kallsyms->symtab = (void *)symsec->sh_addr;
	mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2660
	/* Make sure we get permanent strtab: don't use info->strtab. */
2661
	mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
L
Linus Torvalds 已提交
2662 2663

	/* Set types up while we still have access to sections. */
2664 2665 2666 2667 2668 2669 2670 2671 2672
	for (i = 0; i < mod->kallsyms->num_symtab; i++)
		mod->kallsyms->symtab[i].st_info
			= elf_type(&mod->kallsyms->symtab[i], info);

	/* Now populate the cut down core kallsyms for after init. */
	mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
	mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
	src = mod->kallsyms->symtab;
	for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2673
		if (i == 0 || is_livepatch_module(mod) ||
2674 2675
		    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
				   info->index.pcpu)) {
2676
			dst[ndst] = src[i];
2677 2678
			dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
			s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2679 2680
				     KSYM_NAME_LEN) + 1;
		}
2681
	}
2682
	mod->core_kallsyms.num_symtab = ndst;
L
Linus Torvalds 已提交
2683 2684
}
#else
2685
static inline void layout_symtab(struct module *mod, struct load_info *info)
2686 2687
{
}
2688

2689
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2690 2691 2692 2693
{
}
#endif /* CONFIG_KALLSYMS */

2694
static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2695
{
2696 2697
	if (!debug)
		return;
2698
#ifdef CONFIG_DYNAMIC_DEBUG
2699
	if (ddebug_add_module(debug, num, mod->name))
A
Andrew Morton 已提交
2700 2701
		pr_err("dynamic debug error adding module: %s\n",
			debug->modname);
2702
#endif
R
Rusty Russell 已提交
2703
}
2704

2705
static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2706 2707
{
	if (debug)
2708
		ddebug_remove_module(mod->name);
2709 2710
}

2711 2712
void * __weak module_alloc(unsigned long size)
{
R
Rusty Russell 已提交
2713
	return vmalloc_exec(size);
2714 2715
}

C
Catalin Marinas 已提交
2716
#ifdef CONFIG_DEBUG_KMEMLEAK
2717 2718
static void kmemleak_load_module(const struct module *mod,
				 const struct load_info *info)
C
Catalin Marinas 已提交
2719 2720 2721 2722
{
	unsigned int i;

	/* only scan the sections containing data */
2723
	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
C
Catalin Marinas 已提交
2724

2725
	for (i = 1; i < info->hdr->e_shnum; i++) {
2726 2727 2728 2729
		/* 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
2730 2731
			continue;

2732 2733
		kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
				   info->sechdrs[i].sh_size, GFP_KERNEL);
C
Catalin Marinas 已提交
2734 2735 2736
	}
}
#else
2737 2738
static inline void kmemleak_load_module(const struct module *mod,
					const struct load_info *info)
C
Catalin Marinas 已提交
2739 2740 2741 2742
{
}
#endif

R
Rusty Russell 已提交
2743
#ifdef CONFIG_MODULE_SIG
2744
static int module_sig_check(struct load_info *info, int flags)
R
Rusty Russell 已提交
2745 2746
{
	int err = -ENOKEY;
2747 2748
	const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
	const void *mod = info->hdr;
2749

2750 2751 2752 2753 2754 2755
	/*
	 * Require flags == 0, as a module with version information
	 * removed is no longer the module that was signed
	 */
	if (flags == 0 &&
	    info->len > markerlen &&
2756
	    memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2757
		/* We truncate the module to discard the signature */
2758
		info->len -= markerlen;
2759
		err = mod_verify_sig(mod, info);
R
Rusty Russell 已提交
2760 2761 2762 2763 2764 2765 2766 2767
	}

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

	/* Not having a signature is only an error if we're strict. */
2768
	if (err == -ENOKEY && !is_module_sig_enforced())
R
Rusty Russell 已提交
2769 2770 2771 2772 2773
		err = 0;

	return err;
}
#else /* !CONFIG_MODULE_SIG */
2774
static int module_sig_check(struct load_info *info, int flags)
R
Rusty Russell 已提交
2775 2776 2777 2778 2779
{
	return 0;
}
#endif /* !CONFIG_MODULE_SIG */

2780 2781
/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
static int elf_header_check(struct load_info *info)
2782
{
2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795
	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;
2796

2797 2798 2799
	return 0;
}

2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816
#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;
}

2817
#ifdef CONFIG_LIVEPATCH
2818
static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2819
{
2820 2821 2822
	if (get_modinfo(info, "livepatch")) {
		mod->klp = true;
		add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2823 2824
		pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
			       mod->name);
2825
	}
2826 2827 2828 2829

	return 0;
}
#else /* !CONFIG_LIVEPATCH */
2830
static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841
{
	if (get_modinfo(info, "livepatch")) {
		pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
		       mod->name);
		return -ENOEXEC;
	}

	return 0;
}
#endif /* CONFIG_LIVEPATCH */

2842 2843 2844 2845 2846 2847 2848 2849 2850
static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
{
	if (retpoline_module_ok(get_modinfo(info, "retpoline")))
		return;

	pr_warn("%s: loading module not compiled with retpoline compiler.\n",
		mod->name);
}

2851 2852 2853
/* Sets info->hdr and info->len. */
static int copy_module_from_user(const void __user *umod, unsigned long len,
				  struct load_info *info)
2854 2855 2856
{
	int err;

2857 2858
	info->len = len;
	if (info->len < sizeof(*(info->hdr)))
2859 2860
		return -ENOEXEC;

2861
	err = security_kernel_load_data(LOADING_MODULE);
2862 2863 2864
	if (err)
		return err;

2865
	/* Suck in entire file: we'll want most of it. */
2866
	info->hdr = __vmalloc(info->len,
2867
			GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL);
2868
	if (!info->hdr)
2869 2870
		return -ENOMEM;

2871
	if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2872 2873
		vfree(info->hdr);
		return -EFAULT;
2874 2875
	}

2876 2877 2878
	return 0;
}

R
Rusty Russell 已提交
2879 2880 2881 2882 2883
static void free_copy(struct load_info *info)
{
	vfree(info->hdr);
}

2884
static int rewrite_section_headers(struct load_info *info, int flags)
2885 2886 2887 2888 2889 2890 2891 2892 2893 2894
{
	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
2895
			pr_err("Module len %lu truncated\n", info->len);
2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908
			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
	}
2909 2910

	/* Track but don't keep modinfo and version sections. */
K
Kees Cook 已提交
2911
	info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2912
	info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
K
Kees Cook 已提交
2913

2914 2915 2916
	return 0;
}

L
Linus Torvalds 已提交
2917 2918 2919 2920 2921
/*
 * Set up our basic convenience variables (pointers to section headers,
 * search for module section index etc), and do some basic section
 * verification.
 *
2922 2923
 * Set info->mod to the temporary copy of the module in info->hdr. The final one
 * will be allocated in move_module().
L
Linus Torvalds 已提交
2924
 */
2925
static int setup_load_info(struct load_info *info, int flags)
L
Linus Torvalds 已提交
2926 2927 2928 2929 2930
{
	unsigned int i;

	/* Set up the convenience variables */
	info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2931 2932
	info->secstrings = (void *)info->hdr
		+ info->sechdrs[info->hdr->e_shstrndx].sh_offset;
L
Linus Torvalds 已提交
2933

2934 2935 2936 2937 2938 2939
	/* Try to find a name early so we can log errors with a module name */
	info->index.info = find_sec(info, ".modinfo");
	if (!info->index.info)
		info->name = "(missing .modinfo section)";
	else
		info->name = get_modinfo(info, "name");
L
Linus Torvalds 已提交
2940

2941 2942
	/* Find internal symbols and strings. */
	for (i = 1; i < info->hdr->e_shnum; i++) {
L
Linus Torvalds 已提交
2943 2944 2945
		if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
			info->index.sym = i;
			info->index.str = info->sechdrs[i].sh_link;
2946 2947 2948
			info->strtab = (char *)info->hdr
				+ info->sechdrs[info->index.str].sh_offset;
			break;
L
Linus Torvalds 已提交
2949 2950 2951
		}
	}

2952 2953 2954 2955 2956
	if (info->index.sym == 0) {
		pr_warn("%s: module has no symbols (stripped?)\n", info->name);
		return -ENOEXEC;
	}

2957
	info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
L
Linus Torvalds 已提交
2958
	if (!info->index.mod) {
K
Kees Cook 已提交
2959 2960
		pr_warn("%s: No module found in object\n",
			info->name ?: "(missing .modinfo name field)");
2961
		return -ENOEXEC;
L
Linus Torvalds 已提交
2962 2963
	}
	/* This is temporary: point mod into copy of data. */
2964
	info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
L
Linus Torvalds 已提交
2965

K
Kees Cook 已提交
2966
	/*
2967
	 * If we didn't load the .modinfo 'name' field earlier, fall back to
K
Kees Cook 已提交
2968 2969 2970
	 * on-disk struct mod 'name' field.
	 */
	if (!info->name)
2971
		info->name = info->mod->name;
K
Kees Cook 已提交
2972

2973 2974 2975 2976
	if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
		info->index.vers = 0; /* Pretend no __versions section! */
	else
		info->index.vers = find_sec(info, "__versions");
L
Linus Torvalds 已提交
2977

2978
	info->index.pcpu = find_pcpusec(info);
L
Linus Torvalds 已提交
2979

2980
	return 0;
L
Linus Torvalds 已提交
2981 2982
}

2983
static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2984
{
2985
	const char *modmagic = get_modinfo(info, "vermagic");
2986 2987
	int err;

2988 2989 2990
	if (flags & MODULE_INIT_IGNORE_VERMAGIC)
		modmagic = NULL;

2991 2992 2993 2994 2995
	/* This is allowed: modprobe --force will invalidate it. */
	if (!modmagic) {
		err = try_to_force_load(mod, "bad vermagic");
		if (err)
			return err;
2996
	} else if (!same_magic(modmagic, vermagic, info->index.vers)) {
A
Andrew Morton 已提交
2997
		pr_err("%s: version magic '%s' should be '%s'\n",
K
Kees Cook 已提交
2998
		       info->name, modmagic, vermagic);
2999 3000 3001
		return -ENOEXEC;
	}

3002 3003 3004 3005
	if (!get_modinfo(info, "intree")) {
		if (!test_taint(TAINT_OOT_MODULE))
			pr_warn("%s: loading out-of-tree module taints kernel.\n",
				mod->name);
3006
		add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3007
	}
3008

3009 3010
	check_modinfo_retpoline(mod, info);

3011
	if (get_modinfo(info, "staging")) {
3012
		add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
A
Andrew Morton 已提交
3013 3014
		pr_warn("%s: module is from the staging directory, the quality "
			"is unknown, you have been warned.\n", mod->name);
3015
	}
3016

3017
	err = check_modinfo_livepatch(mod, info);
3018 3019 3020
	if (err)
		return err;

3021
	/* Set up license info based on the info section */
3022
	set_license(mod, get_modinfo(info, "license"));
3023

3024 3025 3026
	return 0;
}

3027
static int find_module_sections(struct module *mod, struct load_info *info)
L
Linus Torvalds 已提交
3028
{
3029
	mod->kp = section_objs(info, "__param",
L
Linus Torvalds 已提交
3030
			       sizeof(*mod->kp), &mod->num_kp);
3031
	mod->syms = section_objs(info, "__ksymtab",
L
Linus Torvalds 已提交
3032
				 sizeof(*mod->syms), &mod->num_syms);
3033 3034
	mod->crcs = section_addr(info, "__kcrctab");
	mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
L
Linus Torvalds 已提交
3035 3036
				     sizeof(*mod->gpl_syms),
				     &mod->num_gpl_syms);
3037 3038
	mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
	mod->gpl_future_syms = section_objs(info,
L
Linus Torvalds 已提交
3039 3040 3041
					    "__ksymtab_gpl_future",
					    sizeof(*mod->gpl_future_syms),
					    &mod->num_gpl_future_syms);
3042
	mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
L
Linus Torvalds 已提交
3043 3044

#ifdef CONFIG_UNUSED_SYMBOLS
3045
	mod->unused_syms = section_objs(info, "__ksymtab_unused",
L
Linus Torvalds 已提交
3046 3047
					sizeof(*mod->unused_syms),
					&mod->num_unused_syms);
3048 3049
	mod->unused_crcs = section_addr(info, "__kcrctab_unused");
	mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
L
Linus Torvalds 已提交
3050 3051
					    sizeof(*mod->unused_gpl_syms),
					    &mod->num_unused_gpl_syms);
3052
	mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
L
Linus Torvalds 已提交
3053 3054
#endif
#ifdef CONFIG_CONSTRUCTORS
3055
	mod->ctors = section_objs(info, ".ctors",
L
Linus Torvalds 已提交
3056
				  sizeof(*mod->ctors), &mod->num_ctors);
3057 3058 3059 3060 3061 3062 3063 3064
	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.
		 */
3065
		pr_warn("%s: has both .ctors and .init_array.\n",
3066 3067 3068
		       mod->name);
		return -EINVAL;
	}
L
Linus Torvalds 已提交
3069 3070 3071
#endif

#ifdef CONFIG_TRACEPOINTS
3072 3073 3074
	mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
					     sizeof(*mod->tracepoints_ptrs),
					     &mod->num_tracepoints);
L
Linus Torvalds 已提交
3075
#endif
3076 3077 3078 3079 3080
#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
3081
#ifdef CONFIG_EVENT_TRACING
3082
	mod->trace_events = section_objs(info, "_ftrace_events",
L
Linus Torvalds 已提交
3083 3084
					 sizeof(*mod->trace_events),
					 &mod->num_trace_events);
3085 3086 3087
	mod->trace_evals = section_objs(info, "_ftrace_eval_map",
					sizeof(*mod->trace_evals),
					&mod->num_trace_evals);
L
Linus Torvalds 已提交
3088
#endif
3089 3090 3091 3092 3093
#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
3094 3095
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
	/* sechdrs[0].sh_size is always zero */
3096
	mod->ftrace_callsites = section_objs(info, "__mcount_loc",
L
Linus Torvalds 已提交
3097 3098 3099
					     sizeof(*mod->ftrace_callsites),
					     &mod->num_ftrace_callsites);
#endif
3100 3101 3102 3103
#ifdef CONFIG_FUNCTION_ERROR_INJECTION
	mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
					    sizeof(*mod->ei_funcs),
					    &mod->num_ei_funcs);
3104
#endif
3105 3106 3107
	mod->extable = section_objs(info, "__ex_table",
				    sizeof(*mod->extable), &mod->num_exentries);

3108
	if (section_addr(info, "__obsparm"))
A
Andrew Morton 已提交
3109
		pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3110 3111 3112

	info->debug = section_objs(info, "__verbose",
				   sizeof(*info->debug), &info->num_debug);
3113 3114

	return 0;
L
Linus Torvalds 已提交
3115 3116
}

3117
static int move_module(struct module *mod, struct load_info *info)
3118 3119 3120 3121 3122
{
	int i;
	void *ptr;

	/* Do the allocs. */
3123
	ptr = module_alloc(mod->core_layout.size);
3124 3125 3126 3127 3128 3129 3130
	/*
	 * 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
3131
		return -ENOMEM;
3132

3133 3134
	memset(ptr, 0, mod->core_layout.size);
	mod->core_layout.base = ptr;
3135

3136 3137
	if (mod->init_layout.size) {
		ptr = module_alloc(mod->init_layout.size);
R
Rusty Russell 已提交
3138 3139 3140 3141 3142 3143 3144 3145
		/*
		 * 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) {
3146
			module_memfree(mod->core_layout.base);
R
Rusty Russell 已提交
3147 3148
			return -ENOMEM;
		}
3149 3150
		memset(ptr, 0, mod->init_layout.size);
		mod->init_layout.base = ptr;
R
Rusty Russell 已提交
3151
	} else
3152
		mod->init_layout.base = NULL;
3153 3154

	/* Transfer each section which specifies SHF_ALLOC */
3155
	pr_debug("final section addresses:\n");
3156
	for (i = 0; i < info->hdr->e_shnum; i++) {
3157
		void *dest;
3158
		Elf_Shdr *shdr = &info->sechdrs[i];
3159

3160
		if (!(shdr->sh_flags & SHF_ALLOC))
3161 3162
			continue;

3163
		if (shdr->sh_entsize & INIT_OFFSET_MASK)
3164
			dest = mod->init_layout.base
3165
				+ (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3166
		else
3167
			dest = mod->core_layout.base + shdr->sh_entsize;
3168

3169 3170
		if (shdr->sh_type != SHT_NOBITS)
			memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3171
		/* Update sh_addr to point to copy in image. */
3172
		shdr->sh_addr = (unsigned long)dest;
3173 3174
		pr_debug("\t0x%lx %s\n",
			 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3175
	}
R
Rusty Russell 已提交
3176 3177

	return 0;
3178 3179
}

3180
static int check_module_license_and_versions(struct module *mod)
3181
{
3182 3183
	int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);

3184 3185 3186 3187 3188 3189
	/*
	 * 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)
3190
		add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3191 3192 3193

	/* driverloader was caught wrongly pretending to be under GPL */
	if (strcmp(mod->name, "driverloader") == 0)
3194 3195
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
3196

3197 3198
	/* lve claims to be GPL but upstream won't provide source */
	if (strcmp(mod->name, "lve") == 0)
3199 3200
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
3201

3202 3203 3204
	if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
		pr_warn("%s: module license taints kernel.\n", mod->name);

3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233
#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.
	 */
3234 3235 3236 3237 3238 3239
	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);
3240 3241 3242 3243

	set_fs(old_fs);
}

3244 3245 3246 3247 3248 3249 3250 3251
int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
				     Elf_Shdr *sechdrs,
				     char *secstrings,
				     struct module *mod)
{
	return 0;
}

3252 3253
/* module_blacklist is a comma-separated list of module names */
static char *module_blacklist;
3254
static bool blacklisted(const char *module_name)
3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272
{
	const char *p;
	size_t len;

	if (!module_blacklist)
		return false;

	for (p = module_blacklist; *p; p += len) {
		len = strcspn(p, ",");
		if (strlen(module_name) == len && !memcmp(module_name, p, len))
			return true;
		if (p[len] == ',')
			len++;
	}
	return false;
}
core_param(module_blacklist, module_blacklist, charp, 0400);

3273
static struct module *layout_and_allocate(struct load_info *info, int flags)
L
Linus Torvalds 已提交
3274 3275
{
	struct module *mod;
J
Jessica Yu 已提交
3276
	unsigned int ndx;
R
Rusty Russell 已提交
3277
	int err;
3278

3279
	err = check_modinfo(info->mod, info, flags);
3280 3281
	if (err)
		return ERR_PTR(err);
L
Linus Torvalds 已提交
3282 3283

	/* Allow arches to frob section contents and sizes.  */
3284
	err = module_frob_arch_sections(info->hdr, info->sechdrs,
3285
					info->secstrings, info->mod);
L
Linus Torvalds 已提交
3286
	if (err < 0)
3287
		return ERR_PTR(err);
L
Linus Torvalds 已提交
3288

3289 3290
	/* 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
3291

J
Jessica Yu 已提交
3292 3293 3294 3295 3296 3297 3298 3299 3300
	/*
	 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
	 * layout_sections() can put it in the right place.
	 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
	 */
	ndx = find_sec(info, ".data..ro_after_init");
	if (ndx)
		info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;

L
Linus Torvalds 已提交
3301 3302 3303
	/* 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. */
3304 3305
	layout_sections(info->mod, info);
	layout_symtab(info->mod, info);
L
Linus Torvalds 已提交
3306

3307
	/* Allocate and move to the final place */
3308
	err = move_module(info->mod, info);
R
Rusty Russell 已提交
3309
	if (err)
3310
		return ERR_PTR(err);
R
Rusty Russell 已提交
3311 3312 3313

	/* Module has been copied to its final place now: return it. */
	mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3314
	kmemleak_load_module(mod, info);
R
Rusty Russell 已提交
3315 3316 3317 3318 3319 3320 3321
	return mod;
}

/* mod is no longer valid after this! */
static void module_deallocate(struct module *mod, struct load_info *info)
{
	percpu_modfree(mod);
3322
	module_arch_freeing_init(mod);
3323 3324
	module_memfree(mod->init_layout.base);
	module_memfree(mod->core_layout.base);
R
Rusty Russell 已提交
3325 3326
}

3327 3328 3329 3330 3331 3332 3333
int __weak module_finalize(const Elf_Ehdr *hdr,
			   const Elf_Shdr *sechdrs,
			   struct module *me)
{
	return 0;
}

3334 3335
static int post_relocation(struct module *mod, const struct load_info *info)
{
3336
	/* Sort exception table now relocations are done. */
3337 3338 3339 3340 3341 3342
	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);

3343
	/* Setup kallsyms-specific fields. */
3344 3345 3346 3347 3348 3349
	add_kallsyms(mod, info);

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

3350 3351 3352 3353 3354 3355
/* Is this module of this name done loading?  No locks held. */
static bool finished_loading(const char *name)
{
	struct module *mod;
	bool ret;

3356 3357 3358 3359 3360 3361
	/*
	 * 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();
3362
	mutex_lock(&module_mutex);
3363
	mod = find_module_all(name, strlen(name), true);
3364 3365
	ret = !mod || mod->state == MODULE_STATE_LIVE
		|| mod->state == MODULE_STATE_GOING;
3366 3367 3368 3369 3370
	mutex_unlock(&module_mutex);

	return ret;
}

3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381
/* 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
}

3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394
/* 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);
}

3395 3396 3397 3398 3399 3400 3401
/*
 * 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)
3402 3403
{
	int ret = 0;
3404 3405 3406 3407 3408 3409 3410
	struct mod_initfree *freeinit;

	freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
	if (!freeinit) {
		ret = -ENOMEM;
		goto fail;
	}
3411
	freeinit->module_init = mod->init_layout.base;
3412

3413 3414 3415 3416 3417 3418
	/*
	 * 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;

3419 3420 3421 3422 3423
	do_mod_ctors(mod);
	/* Start the module */
	if (mod->init != NULL)
		ret = do_one_initcall(mod->init);
	if (ret < 0) {
3424
		goto fail_free_freeinit;
3425 3426
	}
	if (ret > 0) {
A
Andrew Morton 已提交
3427 3428 3429 3430
		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__);
3431 3432 3433 3434 3435 3436 3437 3438
		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);

3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455
	/*
	 * 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
	 */
3456
	if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3457
		async_synchronize_full();
3458

3459
	ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3460
			mod->init_layout.size);
3461 3462 3463 3464 3465
	mutex_lock(&module_mutex);
	/* Drop initial reference. */
	module_put(mod);
	trim_init_extable(mod);
#ifdef CONFIG_KALLSYMS
3466 3467
	/* Switch to core kallsyms now init is done: kallsyms may be walking! */
	rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3468
#endif
J
Jessica Yu 已提交
3469
	module_enable_ro(mod, true);
3470
	mod_tree_remove_init(mod);
R
Rusty Russell 已提交
3471
	disable_ro_nx(&mod->init_layout);
3472
	module_arch_freeing_init(mod);
3473 3474 3475
	mod->init_layout.base = NULL;
	mod->init_layout.size = 0;
	mod->init_layout.ro_size = 0;
J
Jessica Yu 已提交
3476
	mod->init_layout.ro_after_init_size = 0;
3477
	mod->init_layout.text_size = 0;
3478 3479
	/*
	 * We want to free module_init, but be aware that kallsyms may be
3480 3481 3482
	 * 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.
3483 3484 3485 3486 3487
	 * Note that module_alloc() on most architectures creates W+X page
	 * mappings which won't be cleaned up until do_free_init() runs.  Any
	 * code such as mark_rodata_ro() which depends on those mappings to
	 * be cleaned up needs to sync with the queued work - ie
	 * rcu_barrier_sched()
3488
	 */
3489
	call_rcu_sched(&freeinit->rcu, do_free_init);
3490 3491 3492 3493
	mutex_unlock(&module_mutex);
	wake_up_all(&module_wq);

	return 0;
3494 3495 3496 3497 3498 3499 3500 3501 3502 3503

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);
3504
	klp_module_going(mod);
3505
	ftrace_release_mod(mod);
3506 3507 3508
	free_module(mod);
	wake_up_all(&module_wq);
	return ret;
3509 3510 3511 3512 3513 3514 3515 3516 3517 3518
}

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

	return 0;
}

3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532
/*
 * 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);
3533 3534
	old = find_module_all(mod->name, strlen(mod->name), true);
	if (old != NULL) {
3535 3536 3537 3538
		if (old->state == MODULE_STATE_COMING
		    || old->state == MODULE_STATE_UNFORMED) {
			/* Wait in case it fails to load. */
			mutex_unlock(&module_mutex);
3539 3540
			err = wait_event_interruptible(module_wq,
					       finished_loading(mod->name));
3541 3542 3543 3544 3545 3546 3547
			if (err)
				goto out_unlocked;
			goto again;
		}
		err = -EEXIST;
		goto out;
	}
3548
	mod_update_bounds(mod);
3549
	list_add_rcu(&mod->list, &modules);
3550
	mod_tree_insert(mod);
3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572
	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);

J
Jessica Yu 已提交
3573
	module_enable_ro(mod, false);
R
Rusty Russell 已提交
3574
	module_enable_nx(mod);
3575

3576 3577 3578
	/* Mark state as coming so strong_try_module_get() ignores us,
	 * but kallsyms etc. can see us. */
	mod->state = MODULE_STATE_COMING;
3579 3580 3581
	mutex_unlock(&module_mutex);

	return 0;
3582 3583 3584 3585 3586 3587

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

3588 3589
static int prepare_coming_module(struct module *mod)
{
3590 3591
	int err;

3592
	ftrace_module_enable(mod);
3593 3594 3595 3596
	err = klp_module_coming(mod);
	if (err)
		return err;

3597 3598 3599 3600 3601
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_COMING, mod);
	return 0;
}

3602 3603
static int unknown_module_param_cb(char *param, char *val, const char *modname,
				   void *arg)
3604
{
3605 3606 3607 3608 3609 3610 3611 3612
	struct module *mod = arg;
	int ret;

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

3613
	/* Check for magic 'dyndbg' arg */
3614
	ret = ddebug_dyndbg_module_param_cb(param, val, modname);
A
Andrew Morton 已提交
3615 3616
	if (ret != 0)
		pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3617 3618 3619
	return 0;
}

R
Rusty Russell 已提交
3620 3621
/* Allocate and load the module: note that size of section 0 is always
   zero, and we rely on this for optional sections. */
3622 3623
static int load_module(struct load_info *info, const char __user *uargs,
		       int flags)
R
Rusty Russell 已提交
3624
{
3625
	struct module *mod;
3626
	long err = 0;
3627
	char *after_dashes;
R
Rusty Russell 已提交
3628

3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641
	err = elf_header_check(info);
	if (err)
		goto free_copy;

	err = setup_load_info(info, flags);
	if (err)
		goto free_copy;

	if (blacklisted(info->name)) {
		err = -EPERM;
		goto free_copy;
	}

3642
	err = module_sig_check(info, flags);
3643 3644
	if (err)
		goto free_copy;
R
Rusty Russell 已提交
3645

3646
	err = rewrite_section_headers(info, flags);
R
Rusty Russell 已提交
3647
	if (err)
3648
		goto free_copy;
R
Rusty Russell 已提交
3649

3650 3651 3652 3653 3654 3655
	/* Check module struct version now, before we try to use module. */
	if (!check_modstruct_version(info, info->mod)) {
		err = -ENOEXEC;
		goto free_copy;
	}

R
Rusty Russell 已提交
3656
	/* Figure out module layout, and allocate all the memory. */
3657
	mod = layout_and_allocate(info, flags);
3658 3659
	if (IS_ERR(mod)) {
		err = PTR_ERR(mod);
R
Rusty Russell 已提交
3660
		goto free_copy;
L
Linus Torvalds 已提交
3661 3662
	}

3663 3664
	audit_log_kern_module(mod->name);

3665 3666 3667
	/* Reserve our place in the list. */
	err = add_unformed_module(mod);
	if (err)
3668 3669
		goto free_module;

R
Rusty Russell 已提交
3670
#ifdef CONFIG_MODULE_SIG
3671
	mod->sig_ok = info->sig_ok;
3672
	if (!mod->sig_ok) {
A
Andrew Morton 已提交
3673
		pr_notice_once("%s: module verification failed: signature "
3674
			       "and/or required key missing - tainting "
A
Andrew Morton 已提交
3675
			       "kernel\n", mod->name);
3676
		add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3677
	}
R
Rusty Russell 已提交
3678 3679
#endif

3680
	/* To avoid stressing percpu allocator, do this once we're unique. */
R
Rusty Russell 已提交
3681
	err = percpu_modalloc(mod, info);
3682 3683 3684
	if (err)
		goto unlink_mod;

3685
	/* Now module is in final location, initialize linked lists, etc. */
3686 3687
	err = module_unload_init(mod);
	if (err)
3688
		goto unlink_mod;
L
Linus Torvalds 已提交
3689

3690
	init_param_lock(mod);
3691

3692 3693
	/* Now we've got everything in the final locations, we can
	 * find optional sections. */
3694 3695 3696
	err = find_module_sections(mod, info);
	if (err)
		goto free_unload;
3697

3698
	err = check_module_license_and_versions(mod);
3699 3700
	if (err)
		goto free_unload;
3701

3702
	/* Set up MODINFO_ATTR fields */
3703
	setup_modinfo(mod, info);
3704

L
Linus Torvalds 已提交
3705
	/* Fix up syms, so that st_value is a pointer to location. */
3706
	err = simplify_symbols(mod, info);
L
Linus Torvalds 已提交
3707
	if (err < 0)
R
Rusty Russell 已提交
3708
		goto free_modinfo;
L
Linus Torvalds 已提交
3709

3710
	err = apply_relocations(mod, info);
3711
	if (err < 0)
R
Rusty Russell 已提交
3712
		goto free_modinfo;
L
Linus Torvalds 已提交
3713

3714
	err = post_relocation(mod, info);
L
Linus Torvalds 已提交
3715
	if (err < 0)
R
Rusty Russell 已提交
3716
		goto free_modinfo;
L
Linus Torvalds 已提交
3717

3718
	flush_module_icache(mod);
3719

3720 3721 3722 3723 3724 3725
	/* 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
3726

3727
	dynamic_debug_setup(mod, info->debug, info->num_debug);
3728

3729 3730 3731
	/* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
	ftrace_module_init(mod);

3732 3733 3734
	/* Finally it's fully formed, ready to start executing. */
	err = complete_formation(mod, info);
	if (err)
3735
		goto ddebug_cleanup;
3736

3737 3738 3739 3740
	err = prepare_coming_module(mod);
	if (err)
		goto bug_cleanup;

3741
	/* Module is ready to execute: parsing args may do that. */
3742
	after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3743
				  -32768, 32767, mod,
3744
				  unknown_module_param_cb);
3745 3746
	if (IS_ERR(after_dashes)) {
		err = PTR_ERR(after_dashes);
3747
		goto coming_cleanup;
3748 3749 3750 3751
	} else if (after_dashes) {
		pr_warn("%s: parameters '%s' after `--' ignored\n",
		       mod->name, after_dashes);
	}
L
Linus Torvalds 已提交
3752

3753
	/* Link in to sysfs. */
3754
	err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
L
Linus Torvalds 已提交
3755
	if (err < 0)
3756
		goto coming_cleanup;
3757

3758 3759 3760 3761 3762 3763
	if (is_livepatch_module(mod)) {
		err = copy_module_elf(mod, info);
		if (err < 0)
			goto sysfs_cleanup;
	}

3764
	/* Get rid of temporary copy. */
3765
	free_copy(info);
L
Linus Torvalds 已提交
3766 3767

	/* Done! */
3768
	trace_module_load(mod);
3769 3770

	return do_init_module(mod);
L
Linus Torvalds 已提交
3771

3772 3773
 sysfs_cleanup:
	mod_sysfs_teardown(mod);
3774
 coming_cleanup:
3775
	mod->state = MODULE_STATE_GOING;
3776
	destroy_params(mod->kp, mod->num_kp);
3777 3778
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
3779
	klp_module_going(mod);
3780 3781
 bug_cleanup:
	/* module_bug_cleanup needs module_mutex protection */
3782
	mutex_lock(&module_mutex);
3783
	module_bug_cleanup(mod);
3784
	mutex_unlock(&module_mutex);
3785 3786

	/* we can't deallocate the module until we clear memory protection */
R
Rusty Russell 已提交
3787 3788
	module_disable_ro(mod);
	module_disable_nx(mod);
3789

3790
 ddebug_cleanup:
3791
	ftrace_release_mod(mod);
3792
	dynamic_debug_remove(mod, info->debug);
3793
	synchronize_sched();
3794 3795
	kfree(mod->args);
 free_arch_cleanup:
L
Linus Torvalds 已提交
3796
	module_arch_cleanup(mod);
R
Rusty Russell 已提交
3797
 free_modinfo:
3798
	free_modinfo(mod);
3799
 free_unload:
L
Linus Torvalds 已提交
3800
	module_unload_free(mod);
3801 3802 3803 3804
 unlink_mod:
	mutex_lock(&module_mutex);
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
3805
	mod_tree_remove(mod);
3806
	wake_up_all(&module_wq);
3807 3808
	/* Wait for RCU-sched synchronizing before releasing mod->list. */
	synchronize_sched();
3809
	mutex_unlock(&module_mutex);
R
Rusty Russell 已提交
3810
 free_module:
3811
	/* Free lock-classes; relies on the preceding sync_rcu() */
3812
	lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3813

3814
	module_deallocate(mod, info);
R
Rusty Russell 已提交
3815
 free_copy:
3816 3817
	free_copy(info);
	return err;
3818 3819
}

3820 3821
SYSCALL_DEFINE3(init_module, void __user *, umod,
		unsigned long, len, const char __user *, uargs)
L
Linus Torvalds 已提交
3822
{
3823 3824
	int err;
	struct load_info info = { };
L
Linus Torvalds 已提交
3825

3826 3827 3828
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3829

3830 3831
	pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
	       umod, len, uargs);
L
Linus Torvalds 已提交
3832

3833 3834 3835
	err = copy_module_from_user(umod, len, &info);
	if (err)
		return err;
L
Linus Torvalds 已提交
3836

3837
	return load_module(&info, uargs, 0);
3838
}
3839

3840
SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3841 3842
{
	struct load_info info = { };
3843 3844 3845
	loff_t size;
	void *hdr;
	int err;
3846

3847 3848 3849
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3850

3851
	pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3852

3853 3854 3855
	if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
		      |MODULE_INIT_IGNORE_VERMAGIC))
		return -EINVAL;
3856

3857 3858
	err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
				       READING_MODULE);
3859 3860
	if (err)
		return err;
3861 3862
	info.hdr = hdr;
	info.len = size;
L
Linus Torvalds 已提交
3863

3864
	return load_module(&info, uargs, flags);
L
Linus Torvalds 已提交
3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878
}

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 $d.
 */
static inline int is_arm_mapping_symbol(const char *str)
{
3879 3880
	if (str[0] == '.' && str[1] == 'L')
		return true;
K
Kyle McMartin 已提交
3881
	return str[0] == '$' && strchr("axtd", str[1])
L
Linus Torvalds 已提交
3882 3883 3884
	       && (str[2] == '\0' || str[2] == '.');
}

3885
static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
R
Rusty Russell 已提交
3886
{
3887
	return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
R
Rusty Russell 已提交
3888 3889
}

L
Linus Torvalds 已提交
3890 3891 3892 3893 3894 3895 3896
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;
3897
	struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
L
Linus Torvalds 已提交
3898 3899

	/* At worse, next value is at end of module */
3900
	if (within_module_init(addr, mod))
3901
		nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
D
Daniel Walker 已提交
3902
	else
3903
		nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
L
Linus Torvalds 已提交
3904

L
Lucas De Marchi 已提交
3905
	/* Scan for closest preceding symbol, and next symbol. (ELF
D
Daniel Walker 已提交
3906
	   starts real symbols at 1). */
3907 3908
	for (i = 1; i < kallsyms->num_symtab; i++) {
		if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
L
Linus Torvalds 已提交
3909 3910 3911 3912
			continue;

		/* We ignore unnamed symbols: they're uninformative
		 * and inserted at a whim. */
3913 3914
		if (*symname(kallsyms, i) == '\0'
		    || is_arm_mapping_symbol(symname(kallsyms, i)))
R
Rusty Russell 已提交
3915 3916
			continue;

3917 3918
		if (kallsyms->symtab[i].st_value <= addr
		    && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
L
Linus Torvalds 已提交
3919
			best = i;
3920 3921 3922
		if (kallsyms->symtab[i].st_value > addr
		    && kallsyms->symtab[i].st_value < nextval)
			nextval = kallsyms->symtab[i].st_value;
L
Linus Torvalds 已提交
3923 3924 3925 3926 3927
	}

	if (!best)
		return NULL;

A
Alexey Dobriyan 已提交
3928
	if (size)
3929
		*size = nextval - kallsyms->symtab[best].st_value;
A
Alexey Dobriyan 已提交
3930
	if (offset)
3931 3932
		*offset = addr - kallsyms->symtab[best].st_value;
	return symname(kallsyms, best);
L
Linus Torvalds 已提交
3933 3934
}

3935 3936 3937 3938 3939 3940
void * __weak dereference_module_function_descriptor(struct module *mod,
						     void *ptr)
{
	return ptr;
}

3941 3942
/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3943
const char *module_address_lookup(unsigned long addr,
3944 3945 3946 3947
			    unsigned long *size,
			    unsigned long *offset,
			    char **modname,
			    char *namebuf)
L
Linus Torvalds 已提交
3948
{
3949
	const char *ret = NULL;
3950
	struct module *mod;
L
Linus Torvalds 已提交
3951

3952
	preempt_disable();
3953 3954 3955 3956 3957
	mod = __module_address(addr);
	if (mod) {
		if (modname)
			*modname = mod->name;
		ret = get_ksymbol(mod, addr, size, offset);
L
Linus Torvalds 已提交
3958
	}
3959 3960 3961 3962 3963
	/* Make a copy in here where it's safe */
	if (ret) {
		strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
		ret = namebuf;
	}
3964
	preempt_enable();
3965

3966
	return ret;
L
Linus Torvalds 已提交
3967 3968
}

3969 3970 3971 3972
int lookup_module_symbol_name(unsigned long addr, char *symname)
{
	struct module *mod;

3973
	preempt_disable();
3974
	list_for_each_entry_rcu(mod, &modules, list) {
3975 3976
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3977
		if (within_module(addr, mod)) {
3978 3979 3980 3981 3982
			const char *sym;

			sym = get_ksymbol(mod, addr, NULL, NULL);
			if (!sym)
				goto out;
3983
			strlcpy(symname, sym, KSYM_NAME_LEN);
3984
			preempt_enable();
3985 3986 3987 3988
			return 0;
		}
	}
out:
3989
	preempt_enable();
3990 3991 3992
	return -ERANGE;
}

3993 3994 3995 3996 3997
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
			unsigned long *offset, char *modname, char *name)
{
	struct module *mod;

3998
	preempt_disable();
3999
	list_for_each_entry_rcu(mod, &modules, list) {
4000 4001
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
4002
		if (within_module(addr, mod)) {
4003 4004 4005 4006 4007 4008
			const char *sym;

			sym = get_ksymbol(mod, addr, size, offset);
			if (!sym)
				goto out;
			if (modname)
4009
				strlcpy(modname, mod->name, MODULE_NAME_LEN);
4010
			if (name)
4011
				strlcpy(name, sym, KSYM_NAME_LEN);
4012
			preempt_enable();
4013 4014 4015 4016
			return 0;
		}
	}
out:
4017
	preempt_enable();
4018 4019 4020
	return -ERANGE;
}

4021 4022
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
4023 4024 4025
{
	struct module *mod;

4026
	preempt_disable();
4027
	list_for_each_entry_rcu(mod, &modules, list) {
4028 4029
		struct mod_kallsyms *kallsyms;

4030 4031
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
4032 4033 4034 4035 4036
		kallsyms = rcu_dereference_sched(mod->kallsyms);
		if (symnum < kallsyms->num_symtab) {
			*value = kallsyms->symtab[symnum].st_value;
			*type = kallsyms->symtab[symnum].st_info;
			strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
4037
			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4038
			*exported = is_exported(name, *value, mod);
4039
			preempt_enable();
4040
			return 0;
L
Linus Torvalds 已提交
4041
		}
4042
		symnum -= kallsyms->num_symtab;
L
Linus Torvalds 已提交
4043
	}
4044
	preempt_enable();
4045
	return -ERANGE;
L
Linus Torvalds 已提交
4046 4047 4048 4049 4050
}

static unsigned long mod_find_symname(struct module *mod, const char *name)
{
	unsigned int i;
4051
	struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
L
Linus Torvalds 已提交
4052

4053 4054
	for (i = 0; i < kallsyms->num_symtab; i++)
		if (strcmp(name, symname(kallsyms, i)) == 0 &&
4055
		    kallsyms->symtab[i].st_shndx != SHN_UNDEF)
4056
			return kallsyms->symtab[i].st_value;
L
Linus Torvalds 已提交
4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067
	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. */
4068
	preempt_disable();
4069
	if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4070
		if ((mod = find_module_all(name, colon - name, false)) != NULL)
L
Linus Torvalds 已提交
4071 4072
			ret = mod_find_symname(mod, colon+1);
	} else {
4073 4074 4075
		list_for_each_entry_rcu(mod, &modules, list) {
			if (mod->state == MODULE_STATE_UNFORMED)
				continue;
L
Linus Torvalds 已提交
4076 4077
			if ((ret = mod_find_symname(mod, name)) != 0)
				break;
4078
		}
L
Linus Torvalds 已提交
4079
	}
4080
	preempt_enable();
L
Linus Torvalds 已提交
4081 4082
	return ret;
}
4083 4084 4085 4086 4087 4088 4089 4090 4091

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;

4092 4093
	module_assert_mutex();

4094
	list_for_each_entry(mod, &modules, list) {
4095 4096 4097
		/* We hold module_mutex: no need for rcu_dereference_sched */
		struct mod_kallsyms *kallsyms = mod->kallsyms;

4098 4099
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
4100
		for (i = 0; i < kallsyms->num_symtab; i++) {
4101 4102 4103 4104

			if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
				continue;

4105 4106
			ret = fn(data, symname(kallsyms, i),
				 mod, kallsyms->symtab[i].st_value);
4107 4108 4109 4110 4111 4112
			if (ret != 0)
				return ret;
		}
	}
	return 0;
}
L
Linus Torvalds 已提交
4113 4114
#endif /* CONFIG_KALLSYMS */

4115 4116 4117 4118
/* Maximum number of characters written by module_flags() */
#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)

/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4119
static char *module_flags(struct module *mod, char *buf)
4120 4121 4122
{
	int bx = 0;

4123
	BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4124 4125 4126
	if (mod->taints ||
	    mod->state == MODULE_STATE_GOING ||
	    mod->state == MODULE_STATE_COMING) {
4127
		buf[bx++] = '(';
4128
		bx += module_flags_taint(mod, buf + bx);
4129 4130 4131 4132 4133 4134
		/* 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++] = '+';
4135 4136 4137 4138 4139 4140 4141
		buf[bx++] = ')';
	}
	buf[bx] = '\0';

	return buf;
}

4142 4143 4144 4145 4146 4147 4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159
#ifdef CONFIG_PROC_FS
/* Called by the /proc file system to return a list of modules. */
static void *m_start(struct seq_file *m, loff_t *pos)
{
	mutex_lock(&module_mutex);
	return seq_list_start(&modules, *pos);
}

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

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

L
Linus Torvalds 已提交
4160 4161 4162
static int m_show(struct seq_file *m, void *p)
{
	struct module *mod = list_entry(p, struct module, list);
4163
	char buf[MODULE_FLAGS_BUF_SIZE];
4164
	void *value;
4165

4166 4167 4168 4169
	/* We always ignore unformed modules. */
	if (mod->state == MODULE_STATE_UNFORMED)
		return 0;

4170
	seq_printf(m, "%s %u",
4171
		   mod->name, mod->init_layout.size + mod->core_layout.size);
L
Linus Torvalds 已提交
4172 4173 4174 4175
	print_unload_info(m, mod);

	/* Informative for users. */
	seq_printf(m, " %s",
4176 4177
		   mod->state == MODULE_STATE_GOING ? "Unloading" :
		   mod->state == MODULE_STATE_COMING ? "Loading" :
L
Linus Torvalds 已提交
4178 4179
		   "Live");
	/* Used by oprofile and other similar tools. */
4180 4181
	value = m->private ? NULL : mod->core_layout.base;
	seq_printf(m, " 0x%px", value);
L
Linus Torvalds 已提交
4182

4183 4184
	/* Taints info */
	if (mod->taints)
4185
		seq_printf(m, " %s", module_flags(mod, buf));
4186

4187
	seq_puts(m, "\n");
L
Linus Torvalds 已提交
4188 4189 4190 4191 4192 4193 4194 4195
	return 0;
}

/* Format: modulename size refcount deps address

   Where refcount is a number or -, and deps is a comma-separated list
   of depends or -.
*/
4196
static const struct seq_operations modules_op = {
L
Linus Torvalds 已提交
4197 4198 4199 4200 4201 4202
	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= m_show
};

4203 4204 4205 4206 4207 4208 4209
/*
 * This also sets the "private" pointer to non-NULL if the
 * kernel pointers should be hidden (so you can just test
 * "m->private" to see if you should keep the values private).
 *
 * We use the same logic as for /proc/kallsyms.
 */
4210 4211
static int modules_open(struct inode *inode, struct file *file)
{
4212 4213 4214 4215 4216 4217 4218
	int err = seq_open(file, &modules_op);

	if (!err) {
		struct seq_file *m = file->private_data;
		m->private = kallsyms_show_value() ? NULL : (void *)8ul;
	}

4219
	return err;
4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236
}

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

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

L
Linus Torvalds 已提交
4237 4238 4239 4240 4241 4242
/* 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;

R
Rusty Russell 已提交
4243
	preempt_disable();
4244 4245 4246
	mod = __module_address(addr);
	if (!mod)
		goto out;
D
Daniel Walker 已提交
4247

4248 4249 4250 4251
	if (!mod->num_exentries)
		goto out;

	e = search_extable(mod->extable,
4252
			   mod->num_exentries,
4253 4254
			   addr);
out:
R
Rusty Russell 已提交
4255
	preempt_enable();
L
Linus Torvalds 已提交
4256

4257 4258 4259 4260
	/*
	 * Now, if we found one, we are running inside it now, hence
	 * we cannot unload the module, hence no refcnt needed.
	 */
L
Linus Torvalds 已提交
4261 4262 4263
	return e;
}

4264
/*
R
Rusty Russell 已提交
4265 4266 4267 4268 4269
 * 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).
4270
 */
R
Rusty Russell 已提交
4271
bool is_module_address(unsigned long addr)
4272
{
R
Rusty Russell 已提交
4273
	bool ret;
4274

R
Rusty Russell 已提交
4275
	preempt_disable();
R
Rusty Russell 已提交
4276
	ret = __module_address(addr) != NULL;
R
Rusty Russell 已提交
4277
	preempt_enable();
4278

R
Rusty Russell 已提交
4279
	return ret;
4280 4281
}

R
Rusty Russell 已提交
4282 4283 4284 4285 4286 4287 4288
/*
 * __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.
 */
4289
struct module *__module_address(unsigned long addr)
L
Linus Torvalds 已提交
4290 4291 4292
{
	struct module *mod;

4293 4294 4295
	if (addr < module_addr_min || addr > module_addr_max)
		return NULL;

4296 4297
	module_assert_mutex_or_preempt();

4298
	mod = mod_find(addr);
4299 4300
	if (mod) {
		BUG_ON(!within_module(addr, mod));
4301
		if (mod->state == MODULE_STATE_UNFORMED)
4302
			mod = NULL;
4303
	}
4304
	return mod;
L
Linus Torvalds 已提交
4305
}
4306
EXPORT_SYMBOL_GPL(__module_address);
L
Linus Torvalds 已提交
4307

R
Rusty Russell 已提交
4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321 4322 4323 4324 4325 4326 4327 4328 4329 4330 4331 4332 4333 4334 4335 4336 4337 4338
/*
 * 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. */
4339 4340
		if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
		    && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
R
Rusty Russell 已提交
4341 4342 4343 4344
			mod = NULL;
	}
	return mod;
}
4345
EXPORT_SYMBOL_GPL(__module_text_address);
R
Rusty Russell 已提交
4346

L
Linus Torvalds 已提交
4347 4348 4349 4350
/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
	struct module *mod;
4351
	char buf[MODULE_FLAGS_BUF_SIZE];
L
Linus Torvalds 已提交
4352

4353
	printk(KERN_DEFAULT "Modules linked in:");
4354 4355
	/* Most callers should already have preempt disabled, but make sure */
	preempt_disable();
4356 4357 4358
	list_for_each_entry_rcu(mod, &modules, list) {
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
J
Jiri Slaby 已提交
4359
		pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4360
	}
4361
	preempt_enable();
4362
	if (last_unloaded_module[0])
J
Jiri Slaby 已提交
4363 4364
		pr_cont(" [last unloaded: %s]", last_unloaded_module);
	pr_cont("\n");
L
Linus Torvalds 已提交
4365 4366 4367
}

#ifdef CONFIG_MODVERSIONS
4368 4369 4370 4371 4372 4373
/* 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,
4374
		   struct tracepoint * const *tp)
4375 4376 4377
{
}
EXPORT_SYMBOL(module_layout);
L
Linus Torvalds 已提交
4378
#endif