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

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

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

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#ifndef ARCH_SHF_SMALL
#define ARCH_SHF_SMALL 0
#endif

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

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

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/*
 * Mutex protects:
 * 1) List of modules (also safely readable with preempt_disable),
 * 2) module_use links,
 * 3) module_addr_min/module_addr_max.
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 * (delete and add uses RCU list operations). */
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DEFINE_MUTEX(module_mutex);
EXPORT_SYMBOL_GPL(module_mutex);
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static LIST_HEAD(modules);
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#ifdef CONFIG_MODULES_TREE_LOOKUP
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/*
 * Use a latched RB-tree for __module_address(); this allows us to use
 * RCU-sched lookups of the address from any context.
 *
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 * This is conditional on PERF_EVENTS || TRACING because those can really hit
 * __module_address() hard by doing a lot of stack unwinding; potentially from
 * NMI context.
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 */

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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#else /* MODULES_TREE_LOOKUP */

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

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

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

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

	return NULL;
}

#endif /* MODULES_TREE_LOOKUP */

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

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

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

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

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

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

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

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

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

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

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

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

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/*
 * A thread that wants to hold a reference to a module only while it
 * is running can call this to safely exit.  nfsd and lockd use this.
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 */
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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 unsigned long __start___kcrctab[];
extern const unsigned long __start___kcrctab_gpl[];
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extern const unsigned long __start___kcrctab_gpl_future[];
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#ifdef CONFIG_UNUSED_SYMBOLS
extern const struct kernel_symbol __start___ksymtab_unused[];
extern const struct kernel_symbol __stop___ksymtab_unused[];
extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
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extern const unsigned long __start___kcrctab_unused[];
extern const unsigned long __start___kcrctab_unused_gpl[];
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#endif
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#ifndef CONFIG_MODVERSIONS
#define symversion(base, idx) NULL
#else
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#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
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#endif

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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	module_assert_mutex_or_preempt();
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	list_for_each_entry(mod, &modules, list) {
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		if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
			continue;
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		if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
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			return mod;
	}
	return NULL;
}
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struct module *find_module(const char *name)
{
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	module_assert_mutex();
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	return find_module_all(name, strlen(name), false);
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}
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EXPORT_SYMBOL_GPL(find_module);
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#ifdef CONFIG_SMP
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static inline void __percpu *mod_percpu(struct module *mod)
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{
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	return mod->percpu;
}
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static int percpu_modalloc(struct module *mod, struct load_info *info)
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{
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	Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
	unsigned long align = pcpusec->sh_addralign;

	if (!pcpusec->sh_size)
		return 0;

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

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

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static void percpu_modfree(struct module *mod)
645
{
646
	free_percpu(mod->percpu);
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}

649
static unsigned int find_pcpusec(struct load_info *info)
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{
651
	return find_sec(info, ".data..percpu");
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}

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

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

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/**
 * is_module_percpu_address - test whether address is from module static percpu
 * @addr: address to test
 *
 * Test whether @addr belongs to module static percpu area.
 *
 * RETURNS:
 * %true if @addr is from module static percpu area
 */
bool is_module_percpu_address(unsigned long addr)
{
	struct module *mod;
	unsigned int cpu;

	preempt_disable();

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

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

	preempt_enable();
	return false;
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}

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#else /* ... !CONFIG_SMP */
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static inline void __percpu *mod_percpu(struct module *mod)
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{
	return NULL;
}
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static int percpu_modalloc(struct module *mod, struct load_info *info)
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{
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	/* 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;
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}
static inline void percpu_modfree(struct module *mod)
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{
}
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static unsigned int find_pcpusec(struct load_info *info)
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{
	return 0;
}
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static inline void percpu_modcopy(struct module *mod,
				  const void *from, unsigned long size)
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{
	/* pcpusec should be 0, and size of that section should be 0. */
	BUG_ON(size != 0);
}
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bool is_module_percpu_address(unsigned long addr)
{
	return false;
}
729

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#endif /* CONFIG_SMP */

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

MODINFO_ATTR(version);
MODINFO_ATTR(srcversion);

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static char last_unloaded_module[MODULE_NAME_LEN+1];

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#ifdef CONFIG_MODULE_UNLOAD
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EXPORT_TRACEPOINT_SYMBOL(module_get);

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

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/* Init the unload section of the module. */
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static int module_unload_init(struct module *mod)
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{
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	/*
	 * Initialize reference counter to MODULE_REF_BASE.
	 * refcnt == 0 means module is going.
	 */
	atomic_set(&mod->refcnt, MODULE_REF_BASE);
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	INIT_LIST_HEAD(&mod->source_list);
	INIT_LIST_HEAD(&mod->target_list);
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	/* Hold reference count during initialization. */
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	atomic_inc(&mod->refcnt);
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	return 0;
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}

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

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

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/*
 * 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;

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	pr_debug("Allocating new usage for %s.\n", a->name);
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	use = kmalloc(sizeof(*use), GFP_ATOMIC);
	if (!use) {
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		pr_warn("%s: out of memory loading\n", a->name);
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		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;
}

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/* Module a uses b: caller needs module_mutex() */
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int ref_module(struct module *a, struct module *b)
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{
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	int err;
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	if (b == NULL || already_uses(a, b))
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		return 0;

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	/* If module isn't available, we fail. */
	err = strong_try_module_get(b);
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	if (err)
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		return err;
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	err = add_module_usage(a, b);
	if (err) {
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		module_put(b);
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		return err;
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	}
847
	return 0;
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}
849
EXPORT_SYMBOL_GPL(ref_module);
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/* Clear the unload stuff of the module. */
static void module_unload_free(struct module *mod)
{
854
	struct module_use *use, *tmp;
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856
	mutex_lock(&module_mutex);
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	list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
		struct module *i = use->target;
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		pr_debug("%s unusing %s\n", mod->name, i->name);
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		module_put(i);
		list_del(&use->source_list);
		list_del(&use->target_list);
		kfree(use);
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	}
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	mutex_unlock(&module_mutex);
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}

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

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

	/* Mark it as dying. */
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	mod->state = MODULE_STATE_GOING;
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	return 0;
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}

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/**
 * 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)
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{
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	return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
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}
EXPORT_SYMBOL(module_refcount);

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

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

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

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

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	if (mutex_lock_interruptible(&module_mutex) != 0)
		return -EINTR;
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	mod = find_module(name);
	if (!mod) {
		ret = -ENOENT;
		goto out;
	}

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

	/* If it has an init func, it must have an exit func to unload */
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	if (mod->init && !mod->exit) {
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		forced = try_force_unload(flags);
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		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;

983
	mutex_unlock(&module_mutex);
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	/* Final destruction now no one is using it. */
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	if (mod->exit != NULL)
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		mod->exit();
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	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
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	klp_module_going(mod);
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	ftrace_release_mod(mod);

992
	async_synchronize_full();
993

994
	/* Store the name of the last unloaded module for diagnostic purposes */
995
	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
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	free_module(mod);
	return 0;
out:
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	mutex_unlock(&module_mutex);
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	return ret;
}

1004
static inline void print_unload_info(struct seq_file *m, struct module *mod)
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{
	struct module_use *use;
	int printed_something = 0;

1009
	seq_printf(m, " %i ", module_refcount(mod));
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	/*
	 * Always include a trailing , so userspace can differentiate
	 * between this and the old multi-field proc format.
	 */
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	list_for_each_entry(use, &mod->source_list, source_list) {
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		printed_something = 1;
1017
		seq_printf(m, "%s,", use->source->name);
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	}

	if (mod->init != NULL && mod->exit == NULL) {
		printed_something = 1;
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		seq_puts(m, "[permanent],");
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	}

	if (!printed_something)
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		seq_puts(m, "-");
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}

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

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	preempt_disable();
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	if (!find_symbol(symbol, &owner, NULL, true, false))
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		BUG();
	module_put(owner);
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	preempt_enable();
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}
EXPORT_SYMBOL(__symbol_put);

1041
/* Note this assumes addr is a function, which it currently always is. */
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void symbol_put_addr(void *addr)
{
1044
	struct module *modaddr;
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	unsigned long a = (unsigned long)dereference_function_descriptor(addr);
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1047
	if (core_kernel_text(a))
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		return;
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	/*
	 * 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();
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	modaddr = __module_text_address(a);
1056
	BUG_ON(!modaddr);
1057
	module_put(modaddr);
1058
	preempt_enable();
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}
EXPORT_SYMBOL_GPL(symbol_put_addr);

static ssize_t show_refcnt(struct module_attribute *mattr,
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			   struct module_kobject *mk, char *buffer)
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{
1065
	return sprintf(buffer, "%i\n", module_refcount(mk->mod));
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}

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static struct module_attribute modinfo_refcnt =
	__ATTR(refcnt, 0444, show_refcnt, NULL);
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void __module_get(struct module *module)
{
	if (module) {
		preempt_disable();
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		atomic_inc(&module->refcnt);
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		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();
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		/* Note: here, we can fail to get a reference */
		if (likely(module_is_live(module) &&
			   atomic_inc_not_zero(&module->refcnt) != 0))
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			trace_module_get(module, _RET_IP_);
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		else
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			ret = false;

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

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

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	if (module) {
1106
		preempt_disable();
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		ret = atomic_dec_if_positive(&module->refcnt);
		WARN_ON(ret < 0);	/* Failed to put refcount */
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		trace_module_put(module, _RET_IP_);
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		preempt_enable();
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	}
}
EXPORT_SYMBOL(module_put);

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#else /* !CONFIG_MODULE_UNLOAD */
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static inline void print_unload_info(struct seq_file *m, struct module *mod)
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{
	/* We don't know the usage count, or what modules are using. */
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	seq_puts(m, " - -");
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}

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

1126
int ref_module(struct module *a, struct module *b)
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{
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	return strong_try_module_get(b);
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}
1130
EXPORT_SYMBOL_GPL(ref_module);
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1132
static inline int module_unload_init(struct module *mod)
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{
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	return 0;
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}
#endif /* CONFIG_MODULE_UNLOAD */

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static size_t module_flags_taint(struct module *mod, char *buf)
{
	size_t l = 0;

	if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
		buf[l++] = 'P';
	if (mod->taints & (1 << TAINT_OOT_MODULE))
		buf[l++] = 'O';
	if (mod->taints & (1 << TAINT_FORCED_MODULE))
		buf[l++] = 'F';
	if (mod->taints & (1 << TAINT_CRAP))
		buf[l++] = 'C';
1150
	if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1151
		buf[l++] = 'E';
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	if (mod->taints & (1 << TAINT_LIVEPATCH))
		buf[l++] = 'K';
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	/*
	 * TAINT_FORCED_RMMOD: could be added.
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	 * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
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	 * apply to modules.
	 */
	return l;
}

1162
static ssize_t show_initstate(struct module_attribute *mattr,
1163
			      struct module_kobject *mk, char *buffer)
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{
	const char *state = "unknown";

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

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static struct module_attribute modinfo_initstate =
	__ATTR(initstate, 0444, show_initstate, NULL);
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static ssize_t store_uevent(struct module_attribute *mattr,
			    struct module_kobject *mk,
			    const char *buffer, size_t count)
{
	enum kobject_action action;

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

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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)
{
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	return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
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}

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)
{
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	return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
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}

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);
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1231
static struct module_attribute *modinfo_attrs[] = {
1232
	&module_uevent,
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	&modinfo_version,
	&modinfo_srcversion,
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	&modinfo_initstate,
	&modinfo_coresize,
	&modinfo_initsize,
	&modinfo_taint,
1239
#ifdef CONFIG_MODULE_UNLOAD
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	&modinfo_refcnt,
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#endif
	NULL,
};

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static const char vermagic[] = VERMAGIC_STRING;

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static int try_to_force_load(struct module *mod, const char *reason)
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{
#ifdef CONFIG_MODULE_FORCE_LOAD
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	if (!test_taint(TAINT_FORCED_MODULE))
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		pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
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	add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
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	return 0;
#else
	return -ENOEXEC;
#endif
}

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#ifdef CONFIG_MODVERSIONS
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/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
static unsigned long maybe_relocated(unsigned long crc,
				     const struct module *crc_owner)
{
#ifdef ARCH_RELOCATES_KCRCTAB
	if (crc_owner == NULL)
		return crc - (unsigned long)reloc_start;
#endif
	return crc;
}

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static int check_version(Elf_Shdr *sechdrs,
			 unsigned int versindex,
			 const char *symname,
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			 struct module *mod,
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			 const unsigned long *crc,
			 const struct module *crc_owner)
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{
	unsigned int i, num_versions;
	struct modversion_info *versions;

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

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

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	versions = (void *) sechdrs[versindex].sh_addr;
	num_versions = sechdrs[versindex].sh_size
		/ sizeof(struct modversion_info);

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

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		if (versions[i].crc == maybe_relocated(*crc, crc_owner))
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			return 1;
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		pr_debug("Found checksum %lX vs module %lX\n",
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		       maybe_relocated(*crc, crc_owner), versions[i].crc);
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		goto bad_version;
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	}
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	/* Broken toolchain. Warn once, then let it go.. */
	pr_warn_once("%s: no symbol version for %s\n", mod->name, symname);
	return 1;
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bad_version:
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	pr_warn("%s: disagrees about version of symbol %s\n",
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	       mod->name, symname);
	return 0;
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}

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

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	/*
	 * Since this should be found in kernel (which can't be removed), no
	 * locking is necessary -- use preempt_disable() to placate lockdep.
	 */
	preempt_disable();
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	if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
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			 &crc, true, false)) {
		preempt_enable();
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		BUG();
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	}
	preempt_enable();
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	return check_version(sechdrs, versindex,
			     VMLINUX_SYMBOL_STR(module_layout), mod, crc,
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			     NULL);
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}

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/* 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)
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{
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	if (has_crcs) {
		amagic += strcspn(amagic, " ");
		bmagic += strcspn(bmagic, " ");
	}
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	return strcmp(amagic, bmagic) == 0;
}
#else
static inline int check_version(Elf_Shdr *sechdrs,
				unsigned int versindex,
				const char *symname,
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				struct module *mod,
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				const unsigned long *crc,
				const struct module *crc_owner)
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{
	return 1;
}

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

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static inline int same_magic(const char *amagic, const char *bmagic,
			     bool has_crcs)
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{
	return strcmp(amagic, bmagic) == 0;
}
#endif /* CONFIG_MODVERSIONS */

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/* Resolve a symbol for this module.  I.e. if we find one, record usage. */
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static const struct kernel_symbol *resolve_symbol(struct module *mod,
						  const struct load_info *info,
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						  const char *name,
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						  char ownername[])
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{
	struct module *owner;
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	const struct kernel_symbol *sym;
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	const unsigned long *crc;
1380
	int err;
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	/*
	 * 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();
1388
	mutex_lock(&module_mutex);
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	sym = find_symbol(name, &owner, &crc,
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			  !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
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	if (!sym)
		goto unlock;

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	if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
			   owner)) {
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		sym = ERR_PTR(-EINVAL);
		goto getname;
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	}
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	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:
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	mutex_unlock(&module_mutex);
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	return sym;
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}

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static const struct kernel_symbol *
resolve_symbol_wait(struct module *mod,
		    const struct load_info *info,
		    const char *name)
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{
	const struct kernel_symbol *ksym;
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	char owner[MODULE_NAME_LEN];
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	if (wait_event_interruptible_timeout(module_wq,
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			!IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
			|| PTR_ERR(ksym) != -EBUSY,
1425
					     30 * HZ) <= 0) {
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		pr_warn("%s: gave up waiting for init of module %s.\n",
			mod->name, owner);
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	}
	return ksym;
}

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/*
 * /sys/module/foo/sections stuff
 * J. Corbet <corbet@lwn.net>
 */
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#ifdef CONFIG_SYSFS
1437

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#ifdef CONFIG_KALLSYMS
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static inline bool sect_empty(const Elf_Shdr *sect)
{
	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
}

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struct module_sect_attr {
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	struct module_attribute mattr;
	char *name;
	unsigned long address;
};

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struct module_sect_attrs {
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	struct attribute_group grp;
	unsigned int nsections;
	struct module_sect_attr attrs[0];
};

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static ssize_t module_sect_show(struct module_attribute *mattr,
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				struct module_kobject *mk, char *buf)
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{
	struct module_sect_attr *sattr =
		container_of(mattr, struct module_sect_attr, mattr);
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	return sprintf(buf, "0x%pK\n", (void *)sattr->address);
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}

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static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
1466
	unsigned int section;
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	for (section = 0; section < sect_attrs->nsections; section++)
		kfree(sect_attrs->attrs[section].name);
	kfree(sect_attrs);
}

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static void add_sect_attrs(struct module *mod, const struct load_info *info)
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{
	unsigned int nloaded = 0, i, size[2];
	struct module_sect_attrs *sect_attrs;
	struct module_sect_attr *sattr;
	struct attribute **gattr;
1479

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	/* Count loaded sections and allocate structures */
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	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]))
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			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]);
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	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
	if (sect_attrs == NULL)
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		return;

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

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	sect_attrs->nsections = 0;
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	sattr = &sect_attrs->attrs[0];
	gattr = &sect_attrs->grp.attrs[0];
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	for (i = 0; i < info->hdr->e_shnum; i++) {
		Elf_Shdr *sec = &info->sechdrs[i];
		if (sect_empty(sec))
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			continue;
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		sattr->address = sec->sh_addr;
		sattr->name = kstrdup(info->secstrings + sec->sh_name,
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					GFP_KERNEL);
		if (sattr->name == NULL)
			goto out;
		sect_attrs->nsections++;
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		sysfs_attr_init(&sattr->mattr.attr);
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		sattr->mattr.show = module_sect_show;
		sattr->mattr.store = NULL;
		sattr->mattr.attr.name = sattr->name;
		sattr->mattr.attr.mode = S_IRUGO;
		*(gattr++) = &(sattr++)->mattr.attr;
	}
	*gattr = NULL;

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

	mod->sect_attrs = sect_attrs;
	return;
  out:
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	free_sect_attrs(sect_attrs);
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}

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. */
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		free_sect_attrs(mod->sect_attrs);
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		mod->sect_attrs = NULL;
	}
}

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/*
 * /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];
};

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static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
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				 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]);
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		kobject_put(notes_attrs->dir);
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	}
	kfree(notes_attrs);
}

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static void add_notes_attrs(struct module *mod, const struct load_info *info)
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{
	unsigned int notes, loaded, i;
	struct module_notes_attrs *notes_attrs;
	struct bin_attribute *nattr;

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

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	/* Count notes sections and allocate structures.  */
	notes = 0;
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	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]) &&
		    (info->sechdrs[i].sh_type == SHT_NOTE))
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			++notes;

	if (notes == 0)
		return;

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

	notes_attrs->notes = notes;
	nattr = &notes_attrs->attrs[0];
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	for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
		if (sect_empty(&info->sechdrs[i]))
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			continue;
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		if (info->sechdrs[i].sh_type == SHT_NOTE) {
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			sysfs_bin_attr_init(nattr);
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			nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
			nattr->attr.mode = S_IRUGO;
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			nattr->size = info->sechdrs[i].sh_size;
			nattr->private = (void *) info->sechdrs[i].sh_addr;
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			nattr->read = module_notes_read;
			++nattr;
		}
		++loaded;
	}

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	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
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	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);
}

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#else
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static inline void add_sect_attrs(struct module *mod,
				  const struct load_info *info)
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{
}

static inline void remove_sect_attrs(struct module *mod)
{
}
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static inline void add_notes_attrs(struct module *mod,
				   const struct load_info *info)
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{
}

static inline void remove_notes_attrs(struct module *mod)
{
}
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#endif /* CONFIG_KALLSYMS */
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static void add_usage_links(struct module *mod)
{
#ifdef CONFIG_MODULE_UNLOAD
	struct module_use *use;
	int nowarn;

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	mutex_lock(&module_mutex);
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	list_for_each_entry(use, &mod->target_list, target_list) {
		nowarn = sysfs_create_link(use->target->holders_dir,
					   &mod->mkobj.kobj, mod->name);
	}
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	mutex_unlock(&module_mutex);
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#endif
}

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

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	mutex_lock(&module_mutex);
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	list_for_each_entry(use, &mod->target_list, target_list)
		sysfs_remove_link(use->target->holders_dir, mod->name);
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	mutex_unlock(&module_mutex);
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#endif
}

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

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	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;
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	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1700
		if (!attr->test || attr->test(mod)) {
1701
			memcpy(temp_attr, attr, sizeof(*temp_attr));
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			sysfs_attr_init(&temp_attr->attr);
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			error = sysfs_create_file(&mod->mkobj.kobj,
					&temp_attr->attr);
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			++temp_attr;
		}
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	}
	return error;
}

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

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	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
		/* pick a field to test for end of list */
		if (!attr->attr.name)
			break;
1720
		sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
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		if (attr->free)
			attr->free(mod);
1723
	}
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	kfree(mod->modinfo_attrs);
1725
}
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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);
}

1735
static int mod_sysfs_init(struct module *mod)
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{
	int err;
1738
	struct kobject *kobj;
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1739

1740
	if (!module_sysfs_initialized) {
1741
		pr_err("%s: module sysfs not initialized\n", mod->name);
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		err = -EINVAL;
		goto out;
	}
1745 1746 1747

	kobj = kset_find_obj(module_kset, mod->name);
	if (kobj) {
1748
		pr_err("%s: module is already loaded\n", mod->name);
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		kobject_put(kobj);
		err = -EINVAL;
		goto out;
	}

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1754
	mod->mkobj.mod = mod;
1755

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	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)
1761
		mod_kobject_put(mod);
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1762

1763
	/* delay uevent until full sysfs population */
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out:
	return err;
}

1768
static int mod_sysfs_setup(struct module *mod,
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			   const struct load_info *info,
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			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	int err;

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	err = mod_sysfs_init(mod);
	if (err)
		goto out;

1779
	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1780 1781
	if (!mod->holders_dir) {
		err = -ENOMEM;
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		goto out_unreg;
1783
	}
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1784

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	err = module_param_sysfs_setup(mod, kparam, num_params);
	if (err)
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		goto out_unreg_holders;
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1788

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	err = module_add_modinfo_attrs(mod);
	if (err)
1791
		goto out_unreg_param;
1792

1793
	add_usage_links(mod);
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	add_sect_attrs(mod, info);
	add_notes_attrs(mod, info);
1796

1797
	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
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	return 0;

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out_unreg_param:
	module_param_sysfs_remove(mod);
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1802
out_unreg_holders:
1803
	kobject_put(mod->holders_dir);
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1804
out_unreg:
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	mod_kobject_put(mod);
1806
out:
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	return err;
}
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static void mod_sysfs_fini(struct module *mod)
{
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	remove_notes_attrs(mod);
	remove_sect_attrs(mod);
1814
	mod_kobject_put(mod);
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}

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static void init_param_lock(struct module *mod)
{
	mutex_init(&mod->param_lock);
}
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1821
#else /* !CONFIG_SYSFS */
1822

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static int mod_sysfs_setup(struct module *mod,
			   const struct load_info *info,
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			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	return 0;
}

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static void mod_sysfs_fini(struct module *mod)
{
}

1835 1836 1837 1838
static void module_remove_modinfo_attrs(struct module *mod)
{
}

1839 1840 1841 1842
static void del_usage_links(struct module *mod)
{
}

1843 1844 1845
static void init_param_lock(struct module *mod)
{
}
1846
#endif /* CONFIG_SYSFS */
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1847

1848
static void mod_sysfs_teardown(struct module *mod)
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{
1850
	del_usage_links(mod);
1851
	module_remove_modinfo_attrs(mod);
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	module_param_sysfs_remove(mod);
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	kobject_put(mod->mkobj.drivers_dir);
	kobject_put(mod->holders_dir);
1855
	mod_sysfs_fini(mod);
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}

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

1881 1882
static void frob_rodata(const struct module_layout *layout,
			int (*set_memory)(unsigned long start, int num_pages))
1883
{
1884 1885 1886 1887 1888
	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);
1889 1890
}

1891 1892 1893 1894 1895 1896 1897 1898 1899 1900
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);
}

1901 1902
static void frob_writable_data(const struct module_layout *layout,
			       int (*set_memory)(unsigned long start, int num_pages))
1903
{
1904
	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1905
	BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1906
	BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1907 1908
	set_memory((unsigned long)layout->base + layout->ro_after_init_size,
		   (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1909 1910
}

1911 1912
/* livepatching wants to disable read-only so it can frob module. */
void module_disable_ro(const struct module *mod)
1913
{
1914 1915
	frob_text(&mod->core_layout, set_memory_rw);
	frob_rodata(&mod->core_layout, set_memory_rw);
1916
	frob_ro_after_init(&mod->core_layout, set_memory_rw);
1917 1918
	frob_text(&mod->init_layout, set_memory_rw);
	frob_rodata(&mod->init_layout, set_memory_rw);
1919
}
1920

1921
void module_enable_ro(const struct module *mod, bool after_init)
1922
{
1923 1924 1925 1926
	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);
1927 1928 1929

	if (after_init)
		frob_ro_after_init(&mod->core_layout, set_memory_ro);
1930 1931
}

1932
static void module_enable_nx(const struct module *mod)
1933
{
1934
	frob_rodata(&mod->core_layout, set_memory_nx);
1935
	frob_ro_after_init(&mod->core_layout, set_memory_nx);
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	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);
1939 1940
}

1941
static void module_disable_nx(const struct module *mod)
1942
{
1943
	frob_rodata(&mod->core_layout, set_memory_x);
1944
	frob_ro_after_init(&mod->core_layout, set_memory_x);
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	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);
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}

/* Iterate through all modules and set each module's text as RW */
1951
void set_all_modules_text_rw(void)
1952 1953 1954 1955 1956
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1957 1958
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
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		frob_text(&mod->core_layout, set_memory_rw);
		frob_text(&mod->init_layout, set_memory_rw);
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	}
	mutex_unlock(&module_mutex);
}

/* Iterate through all modules and set each module's text as RO */
1967
void set_all_modules_text_ro(void)
1968 1969 1970 1971 1972
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1973 1974
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
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		frob_text(&mod->core_layout, set_memory_ro);
		frob_text(&mod->init_layout, set_memory_ro);
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	}
	mutex_unlock(&module_mutex);
}
1981 1982 1983 1984 1985 1986

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

1992
#else
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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) { }
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#endif

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074
#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;
	mod->klp_info->sechdrs = kmalloc(size, GFP_KERNEL);
	if (mod->klp_info->sechdrs == NULL) {
		ret = -ENOMEM;
		goto free_info;
	}
	memcpy(mod->klp_info->sechdrs, info->sechdrs, size);

	/* Elf section name string table */
	size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
	mod->klp_info->secstrings = kmalloc(size, GFP_KERNEL);
	if (mod->klp_info->secstrings == NULL) {
		ret = -ENOMEM;
		goto free_sechdrs;
	}
	memcpy(mod->klp_info->secstrings, info->secstrings, size);

	/* 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 */

2075
void __weak module_memfree(void *module_region)
2076 2077 2078 2079 2080 2081 2082 2083
{
	vfree(module_region);
}

void __weak module_arch_cleanup(struct module *mod)
{
}

2084 2085 2086 2087
void __weak module_arch_freeing_init(struct module *mod)
{
}

2088
/* Free a module, remove from lists, etc. */
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2089 2090
static void free_module(struct module *mod)
{
2091 2092
	trace_module_free(mod);

2093
	mod_sysfs_teardown(mod);
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2094

2095 2096
	/* We leave it in list to prevent duplicate loads, but make sure
	 * that noone uses it while it's being deconstructed. */
2097
	mutex_lock(&module_mutex);
2098
	mod->state = MODULE_STATE_UNFORMED;
2099
	mutex_unlock(&module_mutex);
2100

2101 2102 2103
	/* Remove dynamic debug info */
	ddebug_remove_module(mod->name);

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	/* Arch-specific cleanup. */
	module_arch_cleanup(mod);

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

2110 2111 2112
	/* Free any allocated parameters. */
	destroy_params(mod->kp, mod->num_kp);

2113 2114 2115
	if (is_livepatch_module(mod))
		free_module_elf(mod);

2116 2117
	/* Now we can delete it from the lists */
	mutex_lock(&module_mutex);
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	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
2120
	mod_tree_remove(mod);
2121
	/* Remove this module from bug list, this uses list_del_rcu */
2122
	module_bug_cleanup(mod);
2123 2124
	/* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
	synchronize_sched();
2125 2126
	mutex_unlock(&module_mutex);

2127 2128
	/* This may be empty, but that's OK */
	disable_ro_nx(&mod->init_layout);
2129
	module_arch_freeing_init(mod);
2130
	module_memfree(mod->init_layout.base);
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2131
	kfree(mod->args);
2132
	percpu_modfree(mod);
2133

2134
	/* Free lock-classes; relies on the preceding sync_rcu(). */
2135
	lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
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2137
	/* Finally, free the core (containing the module structure) */
2138
	disable_ro_nx(&mod->core_layout);
2139
	module_memfree(mod->core_layout.base);
2140 2141 2142 2143

#ifdef CONFIG_MPU
	update_protections(current->mm);
#endif
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}

void *__symbol_get(const char *symbol)
{
	struct module *owner;
2149
	const struct kernel_symbol *sym;
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2150

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	preempt_disable();
2152 2153 2154
	sym = find_symbol(symbol, &owner, NULL, true, true);
	if (sym && strong_try_module_get(owner))
		sym = NULL;
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2155
	preempt_enable();
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2156

2157
	return sym ? (void *)sym->value : NULL;
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}
EXPORT_SYMBOL_GPL(__symbol_get);

2161 2162
/*
 * Ensure that an exported symbol [global namespace] does not already exist
2163
 * in the kernel or in some other module's exported symbol table.
2164 2165
 *
 * You must hold the module_mutex.
2166 2167 2168
 */
static int verify_export_symbols(struct module *mod)
{
2169
	unsigned int i;
2170
	struct module *owner;
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	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 },
2179
#ifdef CONFIG_UNUSED_SYMBOLS
2180 2181
		{ mod->unused_syms, mod->num_unused_syms },
		{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2182
#endif
2183
	};
2184

2185 2186
	for (i = 0; i < ARRAY_SIZE(arr); i++) {
		for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2187
			if (find_symbol(s->name, &owner, NULL, true, false)) {
2188
				pr_err("%s: exports duplicate symbol %s"
2189 2190 2191 2192
				       " (owned by %s)\n",
				       mod->name, s->name, module_name(owner));
				return -ENOEXEC;
			}
2193
		}
2194 2195
	}
	return 0;
2196 2197
}

2198
/* Change all symbols so that st_value encodes the pointer directly. */
2199 2200 2201 2202
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;
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	unsigned long secbase;
2204
	unsigned int i;
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	int ret = 0;
2206
	const struct kernel_symbol *ksym;
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	for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
		const char *name = info->strtab + sym[i].st_name;

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		switch (sym[i].st_shndx) {
		case SHN_COMMON:
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			/* Ignore common symbols */
			if (!strncmp(name, "__gnu_lto", 9))
				break;

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			/* We compiled with -fno-common.  These are not
			   supposed to happen.  */
2219
			pr_debug("Common symbol: %s\n", name);
2220
			pr_warn("%s: please compile with -fno-common\n",
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			       mod->name);
			ret = -ENOEXEC;
			break;

		case SHN_ABS:
			/* Don't need to do anything */
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			pr_debug("Absolute symbol: 0x%08lx\n",
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			       (long)sym[i].st_value);
			break;

2231 2232 2233 2234
		case SHN_LIVEPATCH:
			/* Livepatch symbols are resolved by livepatch */
			break;

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		case SHN_UNDEF:
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			ksym = resolve_symbol_wait(mod, info, name);
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			/* Ok if resolved.  */
2238
			if (ksym && !IS_ERR(ksym)) {
2239
				sym[i].st_value = ksym->value;
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				break;
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			}

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			/* Ok if weak.  */
2244
			if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
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				break;

2247 2248
			pr_warn("%s: Unknown symbol %s (err %li)\n",
				mod->name, name, PTR_ERR(ksym));
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			ret = PTR_ERR(ksym) ?: -ENOENT;
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			break;

		default:
			/* Divert to percpu allocation if a percpu var. */
2254
			if (sym[i].st_shndx == info->index.pcpu)
2255
				secbase = (unsigned long)mod_percpu(mod);
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			else
2257
				secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
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			sym[i].st_value += secbase;
			break;
		}
	}

	return ret;
}

2266
static int apply_relocations(struct module *mod, const struct load_info *info)
2267 2268 2269 2270 2271
{
	unsigned int i;
	int err = 0;

	/* Now do relocations. */
2272 2273
	for (i = 1; i < info->hdr->e_shnum; i++) {
		unsigned int infosec = info->sechdrs[i].sh_info;
2274 2275

		/* Not a valid relocation section? */
2276
		if (infosec >= info->hdr->e_shnum)
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			continue;

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

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

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		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);
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		if (err < 0)
			break;
	}
	return err;
}

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/* 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;
}

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/* Update size with this section: return offset. */
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static long get_offset(struct module *mod, unsigned int *size,
		       Elf_Shdr *sechdr, unsigned int section)
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{
	long ret;

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	*size += arch_mod_section_prepend(mod, section);
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	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. */
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static void layout_sections(struct module *mod, struct load_info *info)
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{
	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 },
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		{ SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
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		{ SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
		{ ARCH_SHF_SMALL | SHF_ALLOC, 0 }
	};
	unsigned int m, i;

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	for (i = 0; i < info->hdr->e_shnum; i++)
		info->sechdrs[i].sh_entsize = ~0UL;
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	pr_debug("Core section allocation order:\n");
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	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
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		for (i = 0; i < info->hdr->e_shnum; ++i) {
			Elf_Shdr *s = &info->sechdrs[i];
			const char *sname = info->secstrings + s->sh_name;
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			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
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			    || strstarts(sname, ".init"))
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				continue;
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			s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
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			pr_debug("\t%s\n", sname);
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		}
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		switch (m) {
		case 0: /* executable */
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			mod->core_layout.size = debug_align(mod->core_layout.size);
			mod->core_layout.text_size = mod->core_layout.size;
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			break;
		case 1: /* RO: text and ro-data */
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			mod->core_layout.size = debug_align(mod->core_layout.size);
			mod->core_layout.ro_size = mod->core_layout.size;
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			break;
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		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 */
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			mod->core_layout.size = debug_align(mod->core_layout.size);
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			break;
		}
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	}

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	pr_debug("Init section allocation order:\n");
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	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
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		for (i = 0; i < info->hdr->e_shnum; ++i) {
			Elf_Shdr *s = &info->sechdrs[i];
			const char *sname = info->secstrings + s->sh_name;
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			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
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			    || !strstarts(sname, ".init"))
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				continue;
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			s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
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					 | INIT_OFFSET_MASK);
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			pr_debug("\t%s\n", sname);
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		}
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		switch (m) {
		case 0: /* executable */
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			mod->init_layout.size = debug_align(mod->init_layout.size);
			mod->init_layout.text_size = mod->init_layout.size;
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			break;
		case 1: /* RO: text and ro-data */
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			mod->init_layout.size = debug_align(mod->init_layout.size);
			mod->init_layout.ro_size = mod->init_layout.size;
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			break;
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		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 */
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			mod->init_layout.size = debug_align(mod->init_layout.size);
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			break;
		}
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	}
}

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

2416
	if (!license_is_gpl_compatible(license)) {
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		if (!test_taint(TAINT_PROPRIETARY_MODULE))
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			pr_warn("%s: module license '%s' taints kernel.\n",
				mod->name, license);
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		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
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	}
}

/* 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;
}

2444
static char *get_modinfo(struct load_info *info, const char *tag)
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{
	char *p;
	unsigned int taglen = strlen(tag);
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	Elf_Shdr *infosec = &info->sechdrs[info->index.info];
	unsigned long size = infosec->sh_size;
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	for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
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		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
			return p + taglen + 1;
	}
	return NULL;
}

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static void setup_modinfo(struct module *mod, struct load_info *info)
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{
	struct module_attribute *attr;
	int i;

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

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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);
	}
}

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#ifdef CONFIG_KALLSYMS
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/* 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)
{
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	return bsearch(name, start, stop - start,
			sizeof(struct kernel_symbol), cmp_name);
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}

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static int is_exported(const char *name, unsigned long value,
		       const struct module *mod)
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{
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	const struct kernel_symbol *ks;
	if (!mod)
		ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
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	else
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		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
	return ks != NULL && ks->value == value;
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}

/* As per nm */
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static char elf_type(const Elf_Sym *sym, const struct load_info *info)
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{
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	const Elf_Shdr *sechdrs = info->sechdrs;

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	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';
2515
	if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
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		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';
	}
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	if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
		      ".debug")) {
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		return 'n';
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	}
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	return '?';
}

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static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2544
			unsigned int shnum, unsigned int pcpundx)
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{
	const Elf_Shdr *sec;

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

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#ifdef CONFIG_KALLSYMS_ALL
	if (src->st_shndx == pcpundx)
		return true;
#endif

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	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;
}

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/*
 * 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>.
 */
2576
static void layout_symtab(struct module *mod, struct load_info *info)
2577
{
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	Elf_Shdr *symsect = info->sechdrs + info->index.sym;
	Elf_Shdr *strsect = info->sechdrs + info->index.str;
2580
	const Elf_Sym *src;
2581
	unsigned int i, nsrc, ndst, strtab_size = 0;
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	/* Put symbol section at end of init part of module. */
	symsect->sh_flags |= SHF_ALLOC;
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	symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2586
					 info->index.sym) | INIT_OFFSET_MASK;
2587
	pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2588

2589
	src = (void *)info->hdr + symsect->sh_offset;
2590
	nsrc = symsect->sh_size / sizeof(*src);
2591

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	/* Compute total space required for the core symbols' strtab. */
2593
	for (ndst = i = 0; i < nsrc; i++) {
2594
		if (i == 0 || is_livepatch_module(mod) ||
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		    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
				   info->index.pcpu)) {
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			strtab_size += strlen(&info->strtab[src[i].st_name])+1;
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			ndst++;
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		}
2600
	}
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	/* Append room for core symbols at end of core part. */
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	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);
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	/* Put string table section at end of init part of module. */
	strsect->sh_flags |= SHF_ALLOC;
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	strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2611
					 info->index.str) | INIT_OFFSET_MASK;
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	pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
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	/* 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);
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}

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/*
 * 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.
 */
2627
static void add_kallsyms(struct module *mod, const struct load_info *info)
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{
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	unsigned int i, ndst;
	const Elf_Sym *src;
	Elf_Sym *dst;
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	char *s;
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	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
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	/* 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);
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	/* Make sure we get permanent strtab: don't use info->strtab. */
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	mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
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	/* Set types up while we still have access to sections. */
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	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++) {
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		if (i == 0 || is_livepatch_module(mod) ||
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		    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
				   info->index.pcpu)) {
2656
			dst[ndst] = src[i];
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			dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
			s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
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				     KSYM_NAME_LEN) + 1;
		}
2661
	}
2662
	mod->core_kallsyms.num_symtab = ndst;
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}
#else
2665
static inline void layout_symtab(struct module *mod, struct load_info *info)
2666 2667
{
}
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2669
static void add_kallsyms(struct module *mod, const struct load_info *info)
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{
}
#endif /* CONFIG_KALLSYMS */

2674
static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2675
{
2676 2677
	if (!debug)
		return;
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#ifdef CONFIG_DYNAMIC_DEBUG
	if (ddebug_add_module(debug, num, debug->modname))
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		pr_err("dynamic debug error adding module: %s\n",
			debug->modname);
2682
#endif
2683
}
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static void dynamic_debug_remove(struct _ddebug *debug)
{
	if (debug)
		ddebug_remove_module(debug->modname);
}

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void * __weak module_alloc(unsigned long size)
{
2693
	return vmalloc_exec(size);
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}

2696
#ifdef CONFIG_DEBUG_KMEMLEAK
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static void kmemleak_load_module(const struct module *mod,
				 const struct load_info *info)
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{
	unsigned int i;

	/* only scan the sections containing data */
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	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
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	for (i = 1; i < info->hdr->e_shnum; i++) {
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		/* 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))
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			continue;

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		kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
				   info->sechdrs[i].sh_size, GFP_KERNEL);
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	}
}
#else
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static inline void kmemleak_load_module(const struct module *mod,
					const struct load_info *info)
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{
}
#endif

2723
#ifdef CONFIG_MODULE_SIG
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static int module_sig_check(struct load_info *info, int flags)
2725 2726
{
	int err = -ENOKEY;
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	const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
	const void *mod = info->hdr;
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	/*
	 * Require flags == 0, as a module with version information
	 * removed is no longer the module that was signed
	 */
	if (flags == 0 &&
	    info->len > markerlen &&
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	    memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
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		/* We truncate the module to discard the signature */
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		info->len -= markerlen;
		err = mod_verify_sig(mod, &info->len);
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	}

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

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

	return err;
}
#else /* !CONFIG_MODULE_SIG */
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static int module_sig_check(struct load_info *info, int flags)
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{
	return 0;
}
#endif /* !CONFIG_MODULE_SIG */

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/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
static int elf_header_check(struct load_info *info)
2762
{
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	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;
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	return 0;
}

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#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;
}

2797
#ifdef CONFIG_LIVEPATCH
2798
static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2799
{
2800 2801 2802 2803
	if (get_modinfo(info, "livepatch")) {
		mod->klp = true;
		add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
	}
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	return 0;
}
#else /* !CONFIG_LIVEPATCH */
2808
static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
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{
	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 */

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

2826 2827
	info->len = len;
	if (info->len < sizeof(*(info->hdr)))
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		return -ENOEXEC;

2830
	err = security_kernel_read_file(NULL, READING_MODULE);
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	if (err)
		return err;

2834
	/* Suck in entire file: we'll want most of it. */
2835 2836
	info->hdr = __vmalloc(info->len,
			GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2837
	if (!info->hdr)
2838 2839
		return -ENOMEM;

2840
	if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2841 2842
		vfree(info->hdr);
		return -EFAULT;
2843 2844
	}

2845 2846 2847
	return 0;
}

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static void free_copy(struct load_info *info)
{
	vfree(info->hdr);
}

2853
static int rewrite_section_headers(struct load_info *info, int flags)
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{
	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) {
2864
			pr_err("Module len %lu truncated\n", info->len);
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			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
	}
2878 2879

	/* Track but don't keep modinfo and version sections. */
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	if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
		info->index.vers = 0; /* Pretend no __versions section! */
	else
		info->index.vers = find_sec(info, "__versions");
2884
	info->index.info = find_sec(info, ".modinfo");
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	info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
	info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
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	return 0;
}

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/*
 * Set up our basic convenience variables (pointers to section headers,
 * search for module section index etc), and do some basic section
 * verification.
 *
 * Return the temporary module pointer (we'll replace it with the final
 * one when we move the module sections around).
 */
2898
static struct module *setup_load_info(struct load_info *info, int flags)
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{
	unsigned int i;
2901
	int err;
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	struct module *mod;

	/* Set up the convenience variables */
	info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
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	info->secstrings = (void *)info->hdr
		+ info->sechdrs[info->hdr->e_shstrndx].sh_offset;
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	err = rewrite_section_headers(info, flags);
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	if (err)
		return ERR_PTR(err);
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	/* Find internal symbols and strings. */
	for (i = 1; i < info->hdr->e_shnum; i++) {
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		if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
			info->index.sym = i;
			info->index.str = info->sechdrs[i].sh_link;
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			info->strtab = (char *)info->hdr
				+ info->sechdrs[info->index.str].sh_offset;
			break;
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		}
	}

2924
	info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
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	if (!info->index.mod) {
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		pr_warn("No module found in object\n");
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		return ERR_PTR(-ENOEXEC);
	}
	/* This is temporary: point mod into copy of data. */
	mod = (void *)info->sechdrs[info->index.mod].sh_addr;

	if (info->index.sym == 0) {
2933
		pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
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		return ERR_PTR(-ENOEXEC);
	}

2937
	info->index.pcpu = find_pcpusec(info);
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	/* Check module struct version now, before we try to use module. */
	if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
		return ERR_PTR(-ENOEXEC);

	return mod;
}

2946
static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2947
{
2948
	const char *modmagic = get_modinfo(info, "vermagic");
2949 2950
	int err;

2951 2952 2953
	if (flags & MODULE_INIT_IGNORE_VERMAGIC)
		modmagic = NULL;

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	/* This is allowed: modprobe --force will invalidate it. */
	if (!modmagic) {
		err = try_to_force_load(mod, "bad vermagic");
		if (err)
			return err;
2959
	} else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2960
		pr_err("%s: version magic '%s' should be '%s'\n",
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		       mod->name, modmagic, vermagic);
		return -ENOEXEC;
	}

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	if (!get_modinfo(info, "intree")) {
		if (!test_taint(TAINT_OOT_MODULE))
			pr_warn("%s: loading out-of-tree module taints kernel.\n",
				mod->name);
2969
		add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2970
	}
2971

2972
	if (get_modinfo(info, "staging")) {
2973
		add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
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		pr_warn("%s: module is from the staging directory, the quality "
			"is unknown, you have been warned.\n", mod->name);
2976
	}
2977

2978
	err = check_modinfo_livepatch(mod, info);
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	if (err)
		return err;

2982
	/* Set up license info based on the info section */
2983
	set_license(mod, get_modinfo(info, "license"));
2984

2985 2986 2987
	return 0;
}

2988
static int find_module_sections(struct module *mod, struct load_info *info)
2989
{
2990
	mod->kp = section_objs(info, "__param",
2991
			       sizeof(*mod->kp), &mod->num_kp);
2992
	mod->syms = section_objs(info, "__ksymtab",
2993
				 sizeof(*mod->syms), &mod->num_syms);
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	mod->crcs = section_addr(info, "__kcrctab");
	mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
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				     sizeof(*mod->gpl_syms),
				     &mod->num_gpl_syms);
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	mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
	mod->gpl_future_syms = section_objs(info,
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					    "__ksymtab_gpl_future",
					    sizeof(*mod->gpl_future_syms),
					    &mod->num_gpl_future_syms);
3003
	mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3004 3005

#ifdef CONFIG_UNUSED_SYMBOLS
3006
	mod->unused_syms = section_objs(info, "__ksymtab_unused",
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					sizeof(*mod->unused_syms),
					&mod->num_unused_syms);
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	mod->unused_crcs = section_addr(info, "__kcrctab_unused");
	mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
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					    sizeof(*mod->unused_gpl_syms),
					    &mod->num_unused_gpl_syms);
3013
	mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
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#endif
#ifdef CONFIG_CONSTRUCTORS
3016
	mod->ctors = section_objs(info, ".ctors",
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				  sizeof(*mod->ctors), &mod->num_ctors);
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	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.
		 */
3026
		pr_warn("%s: has both .ctors and .init_array.\n",
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		       mod->name);
		return -EINVAL;
	}
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#endif

#ifdef CONFIG_TRACEPOINTS
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	mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
					     sizeof(*mod->tracepoints_ptrs),
					     &mod->num_tracepoints);
3036
#endif
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#ifdef HAVE_JUMP_LABEL
	mod->jump_entries = section_objs(info, "__jump_table",
					sizeof(*mod->jump_entries),
					&mod->num_jump_entries);
#endif
3042
#ifdef CONFIG_EVENT_TRACING
3043
	mod->trace_events = section_objs(info, "_ftrace_events",
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					 sizeof(*mod->trace_events),
					 &mod->num_trace_events);
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	mod->trace_enums = section_objs(info, "_ftrace_enum_map",
					sizeof(*mod->trace_enums),
					&mod->num_trace_enums);
3049
#endif
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#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
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#ifdef CONFIG_FTRACE_MCOUNT_RECORD
	/* sechdrs[0].sh_size is always zero */
3057
	mod->ftrace_callsites = section_objs(info, "__mcount_loc",
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					     sizeof(*mod->ftrace_callsites),
					     &mod->num_ftrace_callsites);
#endif
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	mod->extable = section_objs(info, "__ex_table",
				    sizeof(*mod->extable), &mod->num_exentries);

3065
	if (section_addr(info, "__obsparm"))
3066
		pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
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	info->debug = section_objs(info, "__verbose",
				   sizeof(*info->debug), &info->num_debug);
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	return 0;
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}

3074
static int move_module(struct module *mod, struct load_info *info)
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{
	int i;
	void *ptr;

	/* Do the allocs. */
3080
	ptr = module_alloc(mod->core_layout.size);
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	/*
	 * 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)
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		return -ENOMEM;
3089

3090 3091
	memset(ptr, 0, mod->core_layout.size);
	mod->core_layout.base = ptr;
3092

3093 3094
	if (mod->init_layout.size) {
		ptr = module_alloc(mod->init_layout.size);
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		/*
		 * 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) {
3103
			module_memfree(mod->core_layout.base);
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			return -ENOMEM;
		}
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		memset(ptr, 0, mod->init_layout.size);
		mod->init_layout.base = ptr;
3108
	} else
3109
		mod->init_layout.base = NULL;
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	/* Transfer each section which specifies SHF_ALLOC */
3112
	pr_debug("final section addresses:\n");
3113
	for (i = 0; i < info->hdr->e_shnum; i++) {
3114
		void *dest;
3115
		Elf_Shdr *shdr = &info->sechdrs[i];
3116

3117
		if (!(shdr->sh_flags & SHF_ALLOC))
3118 3119
			continue;

3120
		if (shdr->sh_entsize & INIT_OFFSET_MASK)
3121
			dest = mod->init_layout.base
3122
				+ (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3123
		else
3124
			dest = mod->core_layout.base + shdr->sh_entsize;
3125

3126 3127
		if (shdr->sh_type != SHT_NOBITS)
			memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3128
		/* Update sh_addr to point to copy in image. */
3129
		shdr->sh_addr = (unsigned long)dest;
3130 3131
		pr_debug("\t0x%lx %s\n",
			 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3132
	}
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	return 0;
3135 3136
}

3137
static int check_module_license_and_versions(struct module *mod)
3138
{
3139 3140
	int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);

3141 3142 3143 3144 3145 3146
	/*
	 * 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)
3147
		add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3148 3149 3150

	/* driverloader was caught wrongly pretending to be under GPL */
	if (strcmp(mod->name, "driverloader") == 0)
3151 3152
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
3153

3154 3155
	/* lve claims to be GPL but upstream won't provide source */
	if (strcmp(mod->name, "lve") == 0)
3156 3157
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
3158

3159 3160 3161
	if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
		pr_warn("%s: module license taints kernel.\n", mod->name);

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#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.
	 */
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	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);
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	set_fs(old_fs);
}

3201 3202 3203 3204 3205 3206 3207 3208
int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
				     Elf_Shdr *sechdrs,
				     char *secstrings,
				     struct module *mod)
{
	return 0;
}

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/* module_blacklist is a comma-separated list of module names */
static char *module_blacklist;
static bool blacklisted(char *module_name)
{
	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);

3230
static struct module *layout_and_allocate(struct load_info *info, int flags)
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{
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	/* Module within temporary copy. */
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	struct module *mod;
3234
	unsigned int ndx;
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	int err;
3236

3237
	mod = setup_load_info(info, flags);
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	if (IS_ERR(mod))
		return mod;
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3241 3242 3243
	if (blacklisted(mod->name))
		return ERR_PTR(-EPERM);

3244
	err = check_modinfo(mod, info, flags);
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	if (err)
		return ERR_PTR(err);
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	/* Allow arches to frob section contents and sizes.  */
3249 3250
	err = module_frob_arch_sections(info->hdr, info->sechdrs,
					info->secstrings, mod);
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	if (err < 0)
3252
		return ERR_PTR(err);
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3254 3255
	/* We will do a special allocation for per-cpu sections later. */
	info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
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	/*
	 * 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;

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	/* 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. */
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	layout_sections(mod, info);
	layout_symtab(mod, info);
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3272
	/* Allocate and move to the final place */
3273
	err = move_module(mod, info);
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	if (err)
3275
		return ERR_PTR(err);
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	/* Module has been copied to its final place now: return it. */
	mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3279
	kmemleak_load_module(mod, info);
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	return mod;
}

/* mod is no longer valid after this! */
static void module_deallocate(struct module *mod, struct load_info *info)
{
	percpu_modfree(mod);
3287
	module_arch_freeing_init(mod);
3288 3289
	module_memfree(mod->init_layout.base);
	module_memfree(mod->core_layout.base);
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}

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int __weak module_finalize(const Elf_Ehdr *hdr,
			   const Elf_Shdr *sechdrs,
			   struct module *me)
{
	return 0;
}

3299 3300
static int post_relocation(struct module *mod, const struct load_info *info)
{
3301
	/* Sort exception table now relocations are done. */
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	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);

3308
	/* Setup kallsyms-specific fields. */
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	add_kallsyms(mod, info);

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

3315 3316 3317 3318 3319 3320
/* Is this module of this name done loading?  No locks held. */
static bool finished_loading(const char *name)
{
	struct module *mod;
	bool ret;

3321 3322 3323 3324 3325 3326
	/*
	 * 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();
3327
	mutex_lock(&module_mutex);
3328
	mod = find_module_all(name, strlen(name), true);
3329 3330
	ret = !mod || mod->state == MODULE_STATE_LIVE
		|| mod->state == MODULE_STATE_GOING;
3331 3332 3333 3334 3335
	mutex_unlock(&module_mutex);

	return ret;
}

3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346
/* 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
}

3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359
/* 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);
}

3360 3361 3362 3363 3364 3365 3366
/*
 * 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)
3367 3368
{
	int ret = 0;
3369 3370 3371 3372 3373 3374 3375
	struct mod_initfree *freeinit;

	freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
	if (!freeinit) {
		ret = -ENOMEM;
		goto fail;
	}
3376
	freeinit->module_init = mod->init_layout.base;
3377

3378 3379 3380 3381 3382 3383
	/*
	 * 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;

3384 3385 3386 3387 3388
	do_mod_ctors(mod);
	/* Start the module */
	if (mod->init != NULL)
		ret = do_one_initcall(mod->init);
	if (ret < 0) {
3389
		goto fail_free_freeinit;
3390 3391
	}
	if (ret > 0) {
3392 3393 3394 3395
		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__);
3396 3397 3398 3399 3400 3401 3402 3403
		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);

3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420
	/*
	 * 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
	 */
3421
	if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3422
		async_synchronize_full();
3423 3424 3425 3426 3427 3428

	mutex_lock(&module_mutex);
	/* Drop initial reference. */
	module_put(mod);
	trim_init_extable(mod);
#ifdef CONFIG_KALLSYMS
3429 3430
	/* Switch to core kallsyms now init is done: kallsyms may be walking! */
	rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3431
#endif
3432
	module_enable_ro(mod, true);
3433
	mod_tree_remove_init(mod);
3434
	disable_ro_nx(&mod->init_layout);
3435
	module_arch_freeing_init(mod);
3436 3437 3438
	mod->init_layout.base = NULL;
	mod->init_layout.size = 0;
	mod->init_layout.ro_size = 0;
3439
	mod->init_layout.ro_after_init_size = 0;
3440
	mod->init_layout.text_size = 0;
3441 3442
	/*
	 * We want to free module_init, but be aware that kallsyms may be
3443 3444 3445
	 * 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.
3446
	 */
3447
	call_rcu_sched(&freeinit->rcu, do_free_init);
3448 3449 3450 3451
	mutex_unlock(&module_mutex);
	wake_up_all(&module_wq);

	return 0;
3452 3453 3454 3455 3456 3457 3458 3459 3460 3461

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);
3462
	klp_module_going(mod);
3463
	ftrace_release_mod(mod);
3464 3465 3466
	free_module(mod);
	wake_up_all(&module_wq);
	return ret;
3467 3468 3469 3470 3471 3472 3473 3474 3475 3476
}

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

	return 0;
}

3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490
/*
 * 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);
3491 3492
	old = find_module_all(mod->name, strlen(mod->name), true);
	if (old != NULL) {
3493 3494 3495 3496
		if (old->state == MODULE_STATE_COMING
		    || old->state == MODULE_STATE_UNFORMED) {
			/* Wait in case it fails to load. */
			mutex_unlock(&module_mutex);
3497 3498
			err = wait_event_interruptible(module_wq,
					       finished_loading(mod->name));
3499 3500 3501 3502 3503 3504 3505
			if (err)
				goto out_unlocked;
			goto again;
		}
		err = -EEXIST;
		goto out;
	}
3506
	mod_update_bounds(mod);
3507
	list_add_rcu(&mod->list, &modules);
3508
	mod_tree_insert(mod);
3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530
	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);

3531
	module_enable_ro(mod, false);
3532
	module_enable_nx(mod);
3533

3534 3535 3536
	/* Mark state as coming so strong_try_module_get() ignores us,
	 * but kallsyms etc. can see us. */
	mod->state = MODULE_STATE_COMING;
3537 3538 3539
	mutex_unlock(&module_mutex);

	return 0;
3540 3541 3542 3543 3544 3545

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

3546 3547
static int prepare_coming_module(struct module *mod)
{
3548 3549
	int err;

3550
	ftrace_module_enable(mod);
3551 3552 3553 3554
	err = klp_module_coming(mod);
	if (err)
		return err;

3555 3556 3557 3558 3559
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_COMING, mod);
	return 0;
}

3560 3561
static int unknown_module_param_cb(char *param, char *val, const char *modname,
				   void *arg)
3562
{
3563 3564 3565 3566 3567 3568 3569 3570
	struct module *mod = arg;
	int ret;

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

3571
	/* Check for magic 'dyndbg' arg */
3572
	ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3573 3574
	if (ret != 0)
		pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3575 3576 3577
	return 0;
}

Rusty Russell's avatar
Rusty Russell committed
3578 3579
/* Allocate and load the module: note that size of section 0 is always
   zero, and we rely on this for optional sections. */
3580 3581
static int load_module(struct load_info *info, const char __user *uargs,
		       int flags)
Rusty Russell's avatar
Rusty Russell committed
3582
{
3583
	struct module *mod;
Rusty Russell's avatar
Rusty Russell committed
3584
	long err;
3585
	char *after_dashes;
Rusty Russell's avatar
Rusty Russell committed
3586

3587
	err = module_sig_check(info, flags);
3588 3589
	if (err)
		goto free_copy;
Rusty Russell's avatar
Rusty Russell committed
3590

3591
	err = elf_header_check(info);
Rusty Russell's avatar
Rusty Russell committed
3592
	if (err)
3593
		goto free_copy;
Rusty Russell's avatar
Rusty Russell committed
3594 3595

	/* Figure out module layout, and allocate all the memory. */
3596
	mod = layout_and_allocate(info, flags);
3597 3598
	if (IS_ERR(mod)) {
		err = PTR_ERR(mod);
Rusty Russell's avatar
Rusty Russell committed
3599
		goto free_copy;
Linus Torvalds's avatar
Linus Torvalds committed
3600 3601
	}

3602 3603 3604
	/* Reserve our place in the list. */
	err = add_unformed_module(mod);
	if (err)
3605 3606
		goto free_module;

3607
#ifdef CONFIG_MODULE_SIG
3608
	mod->sig_ok = info->sig_ok;
3609
	if (!mod->sig_ok) {
3610
		pr_notice_once("%s: module verification failed: signature "
3611
			       "and/or required key missing - tainting "
3612
			       "kernel\n", mod->name);
3613
		add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3614
	}
3615 3616
#endif

3617
	/* To avoid stressing percpu allocator, do this once we're unique. */
Rusty Russell's avatar
Rusty Russell committed
3618
	err = percpu_modalloc(mod, info);
3619 3620 3621
	if (err)
		goto unlink_mod;

3622
	/* Now module is in final location, initialize linked lists, etc. */
3623 3624
	err = module_unload_init(mod);
	if (err)
3625
		goto unlink_mod;
Linus Torvalds's avatar
Linus Torvalds committed
3626

3627
	init_param_lock(mod);
3628

3629 3630
	/* Now we've got everything in the final locations, we can
	 * find optional sections. */
3631 3632 3633
	err = find_module_sections(mod, info);
	if (err)
		goto free_unload;
3634

3635
	err = check_module_license_and_versions(mod);
3636 3637
	if (err)
		goto free_unload;
3638

3639
	/* Set up MODINFO_ATTR fields */
3640
	setup_modinfo(mod, info);
3641

Linus Torvalds's avatar
Linus Torvalds committed
3642
	/* Fix up syms, so that st_value is a pointer to location. */
3643
	err = simplify_symbols(mod, info);
Linus Torvalds's avatar
Linus Torvalds committed
3644
	if (err < 0)
Rusty Russell's avatar
Rusty Russell committed
3645
		goto free_modinfo;
Linus Torvalds's avatar
Linus Torvalds committed
3646

3647
	err = apply_relocations(mod, info);
3648
	if (err < 0)
Rusty Russell's avatar
Rusty Russell committed
3649
		goto free_modinfo;
Linus Torvalds's avatar
Linus Torvalds committed
3650

3651
	err = post_relocation(mod, info);
Linus Torvalds's avatar
Linus Torvalds committed
3652
	if (err < 0)
Rusty Russell's avatar
Rusty Russell committed
3653
		goto free_modinfo;
Linus Torvalds's avatar
Linus Torvalds committed
3654

3655
	flush_module_icache(mod);
3656

3657 3658 3659 3660 3661 3662
	/* 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;
	}
Rusty Russell's avatar
Rusty Russell committed
3663

3664
	dynamic_debug_setup(info->debug, info->num_debug);
3665

3666 3667 3668
	/* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
	ftrace_module_init(mod);

3669 3670 3671
	/* Finally it's fully formed, ready to start executing. */
	err = complete_formation(mod, info);
	if (err)
3672
		goto ddebug_cleanup;
3673

3674 3675 3676 3677
	err = prepare_coming_module(mod);
	if (err)
		goto bug_cleanup;

3678
	/* Module is ready to execute: parsing args may do that. */
3679
	after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3680
				  -32768, 32767, mod,
3681
				  unknown_module_param_cb);
3682 3683
	if (IS_ERR(after_dashes)) {
		err = PTR_ERR(after_dashes);
3684
		goto coming_cleanup;
3685 3686 3687 3688
	} else if (after_dashes) {
		pr_warn("%s: parameters '%s' after `--' ignored\n",
		       mod->name, after_dashes);
	}
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Linus Torvalds committed
3689

3690
	/* Link in to syfs. */
3691
	err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
Linus Torvalds's avatar
Linus Torvalds committed
3692
	if (err < 0)
3693
		goto coming_cleanup;
3694

3695 3696 3697 3698 3699 3700
	if (is_livepatch_module(mod)) {
		err = copy_module_elf(mod, info);
		if (err < 0)
			goto sysfs_cleanup;
	}

3701
	/* Get rid of temporary copy. */
3702
	free_copy(info);
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Linus Torvalds committed
3703 3704

	/* Done! */
3705
	trace_module_load(mod);
3706 3707

	return do_init_module(mod);
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Linus Torvalds committed
3708

3709 3710
 sysfs_cleanup:
	mod_sysfs_teardown(mod);
3711 3712 3713
 coming_cleanup:
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
3714
	klp_module_going(mod);
3715 3716
 bug_cleanup:
	/* module_bug_cleanup needs module_mutex protection */
3717
	mutex_lock(&module_mutex);
3718
	module_bug_cleanup(mod);
3719
	mutex_unlock(&module_mutex);
3720 3721

	/* we can't deallocate the module until we clear memory protection */
3722 3723
	module_disable_ro(mod);
	module_disable_nx(mod);
3724

3725
 ddebug_cleanup:
3726
	dynamic_debug_remove(info->debug);
3727
	synchronize_sched();
3728 3729
	kfree(mod->args);
 free_arch_cleanup:
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Linus Torvalds committed
3730
	module_arch_cleanup(mod);
Rusty Russell's avatar
Rusty Russell committed
3731
 free_modinfo:
3732
	free_modinfo(mod);
3733
 free_unload:
Linus Torvalds's avatar
Linus Torvalds committed
3734
	module_unload_free(mod);
3735 3736 3737 3738
 unlink_mod:
	mutex_lock(&module_mutex);
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
3739
	mod_tree_remove(mod);
3740
	wake_up_all(&module_wq);
3741 3742
	/* Wait for RCU-sched synchronizing before releasing mod->list. */
	synchronize_sched();
3743
	mutex_unlock(&module_mutex);
Rusty Russell's avatar
Rusty Russell committed
3744
 free_module:
3745 3746 3747 3748 3749 3750
	/*
	 * Ftrace needs to clean up what it initialized.
	 * This does nothing if ftrace_module_init() wasn't called,
	 * but it must be called outside of module_mutex.
	 */
	ftrace_release_mod(mod);
3751
	/* Free lock-classes; relies on the preceding sync_rcu() */
3752
	lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3753

3754
	module_deallocate(mod, info);
Rusty Russell's avatar
Rusty Russell committed
3755
 free_copy:
3756 3757
	free_copy(info);
	return err;
3758 3759
}

3760 3761
SYSCALL_DEFINE3(init_module, void __user *, umod,
		unsigned long, len, const char __user *, uargs)
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Linus Torvalds committed
3762
{
3763 3764
	int err;
	struct load_info info = { };
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Linus Torvalds committed
3765

3766 3767 3768
	err = may_init_module();
	if (err)
		return err;
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Linus Torvalds committed
3769

3770 3771
	pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
	       umod, len, uargs);
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Linus Torvalds committed
3772

3773 3774 3775
	err = copy_module_from_user(umod, len, &info);
	if (err)
		return err;
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Linus Torvalds committed
3776

3777
	return load_module(&info, uargs, 0);
3778
}
3779

3780
SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3781 3782
{
	struct load_info info = { };
3783 3784 3785
	loff_t size;
	void *hdr;
	int err;
3786

3787 3788 3789
	err = may_init_module();
	if (err)
		return err;
Linus Torvalds's avatar
Linus Torvalds committed
3790

3791
	pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3792

3793 3794 3795
	if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
		      |MODULE_INIT_IGNORE_VERMAGIC))
		return -EINVAL;
3796

3797 3798
	err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
				       READING_MODULE);
3799 3800
	if (err)
		return err;
3801 3802
	info.hdr = hdr;
	info.len = size;
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Linus Torvalds committed
3803

3804
	return load_module(&info, uargs, flags);
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3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818
}

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 $d.
 */
static inline int is_arm_mapping_symbol(const char *str)
{
3819 3820
	if (str[0] == '.' && str[1] == 'L')
		return true;
3821
	return str[0] == '$' && strchr("axtd", str[1])
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Linus Torvalds committed
3822 3823 3824
	       && (str[2] == '\0' || str[2] == '.');
}

3825
static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3826
{
3827
	return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3828 3829
}

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Linus Torvalds committed
3830 3831 3832 3833 3834 3835 3836
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;
3837
	struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
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Linus Torvalds committed
3838 3839

	/* At worse, next value is at end of module */
3840
	if (within_module_init(addr, mod))
3841
		nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3842
	else
3843
		nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
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Linus Torvalds committed
3844

Lucas De Marchi's avatar
Lucas De Marchi committed
3845
	/* Scan for closest preceding symbol, and next symbol. (ELF
3846
	   starts real symbols at 1). */
3847 3848
	for (i = 1; i < kallsyms->num_symtab; i++) {
		if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
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Linus Torvalds committed
3849 3850 3851 3852
			continue;

		/* We ignore unnamed symbols: they're uninformative
		 * and inserted at a whim. */
3853 3854
		if (*symname(kallsyms, i) == '\0'
		    || is_arm_mapping_symbol(symname(kallsyms, i)))
3855 3856
			continue;

3857 3858
		if (kallsyms->symtab[i].st_value <= addr
		    && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
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Linus Torvalds committed
3859
			best = i;
3860 3861 3862
		if (kallsyms->symtab[i].st_value > addr
		    && kallsyms->symtab[i].st_value < nextval)
			nextval = kallsyms->symtab[i].st_value;
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Linus Torvalds committed
3863 3864 3865 3866 3867
	}

	if (!best)
		return NULL;

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Alexey Dobriyan committed
3868
	if (size)
3869
		*size = nextval - kallsyms->symtab[best].st_value;
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Alexey Dobriyan committed
3870
	if (offset)
3871 3872
		*offset = addr - kallsyms->symtab[best].st_value;
	return symname(kallsyms, best);
Linus Torvalds's avatar
Linus Torvalds committed
3873 3874
}

3875 3876
/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3877
const char *module_address_lookup(unsigned long addr,
3878 3879 3880 3881
			    unsigned long *size,
			    unsigned long *offset,
			    char **modname,
			    char *namebuf)
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{
3883
	const char *ret = NULL;
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	struct module *mod;
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	preempt_disable();
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	mod = __module_address(addr);
	if (mod) {
		if (modname)
			*modname = mod->name;
		ret = get_ksymbol(mod, addr, size, offset);
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	}
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	/* Make a copy in here where it's safe */
	if (ret) {
		strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
		ret = namebuf;
	}
3898
	preempt_enable();
3899

3900
	return ret;
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}

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

3907
	preempt_disable();
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	list_for_each_entry_rcu(mod, &modules, list) {
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		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
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		if (within_module(addr, mod)) {
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			const char *sym;

			sym = get_ksymbol(mod, addr, NULL, NULL);
			if (!sym)
				goto out;
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			strlcpy(symname, sym, KSYM_NAME_LEN);
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			preempt_enable();
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			return 0;
		}
	}
out:
3923
	preempt_enable();
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	return -ERANGE;
}

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int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
			unsigned long *offset, char *modname, char *name)
{
	struct module *mod;

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	preempt_disable();
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	list_for_each_entry_rcu(mod, &modules, list) {
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		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3936
		if (within_module(addr, mod)) {
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			const char *sym;

			sym = get_ksymbol(mod, addr, size, offset);
			if (!sym)
				goto out;
			if (modname)
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				strlcpy(modname, mod->name, MODULE_NAME_LEN);
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			if (name)
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				strlcpy(name, sym, KSYM_NAME_LEN);
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			preempt_enable();
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			return 0;
		}
	}
out:
3951
	preempt_enable();
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	return -ERANGE;
}

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int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
			char *name, char *module_name, int *exported)
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{
	struct module *mod;

3960
	preempt_disable();
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	list_for_each_entry_rcu(mod, &modules, list) {
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		struct mod_kallsyms *kallsyms;

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		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
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		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);
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			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
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			*exported = is_exported(name, *value, mod);
3973
			preempt_enable();
3974
			return 0;
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		}
3976
		symnum -= kallsyms->num_symtab;
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	}
3978
	preempt_enable();
3979
	return -ERANGE;
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}

static unsigned long mod_find_symname(struct module *mod, const char *name)
{
	unsigned int i;
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	struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
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	for (i = 0; i < kallsyms->num_symtab; i++)
		if (strcmp(name, symname(kallsyms, i)) == 0 &&
		    kallsyms->symtab[i].st_info != 'U')
			return kallsyms->symtab[i].st_value;
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	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. */
4002
	preempt_disable();
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	if ((colon = strchr(name, ':')) != NULL) {
4004
		if ((mod = find_module_all(name, colon - name, false)) != NULL)
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			ret = mod_find_symname(mod, colon+1);
	} else {
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		list_for_each_entry_rcu(mod, &modules, list) {
			if (mod->state == MODULE_STATE_UNFORMED)
				continue;
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			if ((ret = mod_find_symname(mod, name)) != 0)
				break;
4012
		}
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	}
4014
	preempt_enable();
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	return ret;
}
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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;

4026 4027
	module_assert_mutex();

4028
	list_for_each_entry(mod, &modules, list) {
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		/* We hold module_mutex: no need for rcu_dereference_sched */
		struct mod_kallsyms *kallsyms = mod->kallsyms;

4032 4033
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
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		for (i = 0; i < kallsyms->num_symtab; i++) {
			ret = fn(data, symname(kallsyms, i),
				 mod, kallsyms->symtab[i].st_value);
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			if (ret != 0)
				return ret;
		}
	}
	return 0;
}
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#endif /* CONFIG_KALLSYMS */

4045
static char *module_flags(struct module *mod, char *buf)
4046 4047 4048
{
	int bx = 0;

4049
	BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4050 4051 4052
	if (mod->taints ||
	    mod->state == MODULE_STATE_GOING ||
	    mod->state == MODULE_STATE_COMING) {
4053
		buf[bx++] = '(';
4054
		bx += module_flags_taint(mod, buf + bx);
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		/* 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++] = '+';
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		buf[bx++] = ')';
	}
	buf[bx] = '\0';

	return buf;
}

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#ifdef CONFIG_PROC_FS
/* Called by the /proc file system to return a list of modules. */
static void *m_start(struct seq_file *m, loff_t *pos)
{
	mutex_lock(&module_mutex);
	return seq_list_start(&modules, *pos);
}

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

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

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static int m_show(struct seq_file *m, void *p)
{
	struct module *mod = list_entry(p, struct module, list);
4089 4090
	char buf[8];

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

4095
	seq_printf(m, "%s %u",
4096
		   mod->name, mod->init_layout.size + mod->core_layout.size);
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	print_unload_info(m, mod);

	/* Informative for users. */
	seq_printf(m, " %s",
4101 4102
		   mod->state == MODULE_STATE_GOING ? "Unloading" :
		   mod->state == MODULE_STATE_COMING ? "Loading" :
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		   "Live");
	/* Used by oprofile and other similar tools. */
4105
	seq_printf(m, " 0x%pK", mod->core_layout.base);
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4107 4108
	/* Taints info */
	if (mod->taints)
4109
		seq_printf(m, " %s", module_flags(mod, buf));
4110

4111
	seq_puts(m, "\n");
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	return 0;
}

/* Format: modulename size refcount deps address

   Where refcount is a number or -, and deps is a comma-separated list
   of depends or -.
*/
4120
static const struct seq_operations modules_op = {
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	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= m_show
};

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static int modules_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &modules_op);
}

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

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

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/* Given an address, look for it in the module exception tables. */
const struct exception_table_entry *search_module_extables(unsigned long addr)
{
	const struct exception_table_entry *e = NULL;
	struct module *mod;

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	preempt_disable();
4154
	list_for_each_entry_rcu(mod, &modules, list) {
4155 4156
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
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		if (mod->num_exentries == 0)
			continue;
4159

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		e = search_extable(mod->extable,
				   mod->extable + mod->num_exentries - 1,
				   addr);
		if (e)
			break;
	}
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	preempt_enable();
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	/* Now, if we found one, we are running inside it now, hence
4169
	   we cannot unload the module, hence no refcnt needed. */
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	return e;
}

4173
/*
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 * is_module_address - is this address inside a module?
 * @addr: the address to check.
 *
 * See is_module_text_address() if you simply want to see if the address
 * is code (not data).
4179
 */
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bool is_module_address(unsigned long addr)
4181
{
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	bool ret;
4183

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	preempt_disable();
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	ret = __module_address(addr) != NULL;
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	preempt_enable();
4187

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	return ret;
4189 4190
}

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/*
 * __module_address - get the module which contains an address.
 * @addr: the address.
 *
 * Must be called with preempt disabled or module mutex held so that
 * module doesn't get freed during this.
 */
4198
struct module *__module_address(unsigned long addr)
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{
	struct module *mod;

4202 4203 4204
	if (addr < module_addr_min || addr > module_addr_max)
		return NULL;

4205 4206
	module_assert_mutex_or_preempt();

4207
	mod = mod_find(addr);
4208 4209
	if (mod) {
		BUG_ON(!within_module(addr, mod));
4210
		if (mod->state == MODULE_STATE_UNFORMED)
4211
			mod = NULL;
4212
	}
4213
	return mod;
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}
4215
EXPORT_SYMBOL_GPL(__module_address);
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/*
 * is_module_text_address - is this address inside module code?
 * @addr: the address to check.
 *
 * See is_module_address() if you simply want to see if the address is
 * anywhere in a module.  See kernel_text_address() for testing if an
 * address corresponds to kernel or module code.
 */
bool is_module_text_address(unsigned long addr)
{
	bool ret;

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

	return ret;
}

/*
 * __module_text_address - get the module whose code contains an address.
 * @addr: the address.
 *
 * Must be called with preempt disabled or module mutex held so that
 * module doesn't get freed during this.
 */
struct module *__module_text_address(unsigned long addr)
{
	struct module *mod = __module_address(addr);
	if (mod) {
		/* Make sure it's within the text section. */
4248 4249
		if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
		    && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
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			mod = NULL;
	}
	return mod;
}
4254
EXPORT_SYMBOL_GPL(__module_text_address);
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/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
	struct module *mod;
4260
	char buf[8];
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4262
	printk(KERN_DEFAULT "Modules linked in:");
4263 4264
	/* Most callers should already have preempt disabled, but make sure */
	preempt_disable();
4265 4266 4267
	list_for_each_entry_rcu(mod, &modules, list) {
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
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		pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4269
	}
4270
	preempt_enable();
4271
	if (last_unloaded_module[0])
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		pr_cont(" [last unloaded: %s]", last_unloaded_module);
	pr_cont("\n");
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}

#ifdef CONFIG_MODVERSIONS
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/* 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,
4283
		   struct tracepoint * const *tp)
4284 4285 4286
{
}
EXPORT_SYMBOL(module_layout);
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#endif