module.c 96.7 KB
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/*
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   Copyright (C) 2002 Richard Henderson
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   Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
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    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

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

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

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#ifndef ARCH_SHF_SMALL
#define ARCH_SHF_SMALL 0
#endif

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

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

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

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/*
 * Mutex protects:
 * 1) List of modules (also safely readable with preempt_disable),
 * 2) module_use links,
 * 3) module_addr_min/module_addr_max.
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 * (delete and add uses RCU list operations). */
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DEFINE_MUTEX(module_mutex);
EXPORT_SYMBOL_GPL(module_mutex);
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static LIST_HEAD(modules);
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#ifdef CONFIG_KGDB_KDB
struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
#endif /* CONFIG_KGDB_KDB */

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#ifdef CONFIG_MODULE_SIG
#ifdef CONFIG_MODULE_SIG_FORCE
static bool sig_enforce = true;
#else
static bool sig_enforce = false;

static int param_set_bool_enable_only(const char *val,
				      const struct kernel_param *kp)
{
	int err;
	bool test;
	struct kernel_param dummy_kp = *kp;

	dummy_kp.arg = &test;

	err = param_set_bool(val, &dummy_kp);
	if (err)
		return err;

	/* Don't let them unset it once it's set! */
	if (!test && sig_enforce)
		return -EROFS;

	if (test)
		sig_enforce = true;
	return 0;
}

static const struct kernel_param_ops param_ops_bool_enable_only = {
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	.flags = KERNEL_PARAM_OPS_FL_NOARG,
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	.set = param_set_bool_enable_only,
	.get = param_get_bool,
};
#define param_check_bool_enable_only param_check_bool

module_param(sig_enforce, bool_enable_only, 0644);
#endif /* !CONFIG_MODULE_SIG_FORCE */
#endif /* CONFIG_MODULE_SIG */
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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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/* Bounds of module allocation, for speeding __module_address.
 * Protected by module_mutex. */
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static unsigned long module_addr_min = -1UL, module_addr_max = 0;

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

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

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

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

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

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

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

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

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

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

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

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/* Returns true as soon as fn returns true, otherwise false. */
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bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
				    struct module *owner,
				    void *data),
			 void *data)
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{
	struct module *mod;
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	static const struct symsearch arr[] = {
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		{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
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		  NOT_GPL_ONLY, false },
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		{ __start___ksymtab_gpl, __stop___ksymtab_gpl,
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		  __start___kcrctab_gpl,
		  GPL_ONLY, false },
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		{ __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
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		  __start___kcrctab_gpl_future,
		  WILL_BE_GPL_ONLY, false },
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#ifdef CONFIG_UNUSED_SYMBOLS
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		{ __start___ksymtab_unused, __stop___ksymtab_unused,
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		  __start___kcrctab_unused,
		  NOT_GPL_ONLY, true },
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		{ __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
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		  __start___kcrctab_unused_gpl,
		  GPL_ONLY, true },
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#endif
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	};
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	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");
		pr_warn("Please evalute if this is the right api to use and if "
			"it really is, submit a report the linux kernel "
			"mailinglist together with submitting your code for "
			"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. */
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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;

	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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	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)
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{
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	free_percpu(mod->percpu);
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}

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static unsigned int find_pcpusec(struct load_info *info)
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{
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	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;
}
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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)                  \
{                                                                     \
610 611
	kfree(mod->field);                                            \
	mod->field = NULL;                                            \
612 613
}                                                                     \
static struct module_attribute modinfo_##field = {                    \
614
	.attr = { .name = __stringify(field), .mode = 0444 },         \
615 616 617 618 619 620 621 622 623
	.show = show_modinfo_##field,                                 \
	.setup = setup_modinfo_##field,                               \
	.test = modinfo_##field##_exists,                             \
	.free = free_modinfo_##field,                                 \
};

MODINFO_ATTR(version);
MODINFO_ATTR(srcversion);

624 625
static char last_unloaded_module[MODULE_NAME_LEN+1];

626
#ifdef CONFIG_MODULE_UNLOAD
627 628 629

EXPORT_TRACEPOINT_SYMBOL(module_get);

630 631 632
/* MODULE_REF_BASE is the base reference count by kmodule loader. */
#define MODULE_REF_BASE	1

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633
/* Init the unload section of the module. */
634
static int module_unload_init(struct module *mod)
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635
{
636 637 638 639 640
	/*
	 * Initialize reference counter to MODULE_REF_BASE.
	 * refcnt == 0 means module is going.
	 */
	atomic_set(&mod->refcnt, MODULE_REF_BASE);
641

642 643
	INIT_LIST_HEAD(&mod->source_list);
	INIT_LIST_HEAD(&mod->target_list);
644

L
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645
	/* Hold reference count during initialization. */
646
	atomic_inc(&mod->refcnt);
647 648

	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;

656 657
	list_for_each_entry(use, &b->source_list, source_list) {
		if (use->source == a) {
658
			pr_debug("%s uses %s!\n", a->name, b->name);
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			return 1;
		}
	}
662
	pr_debug("%s does not use %s!\n", a->name, b->name);
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663 664 665
	return 0;
}

666 667 668 669 670 671 672 673 674 675 676
/*
 * 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;

677
	pr_debug("Allocating new usage for %s.\n", a->name);
678 679
	use = kmalloc(sizeof(*use), GFP_ATOMIC);
	if (!use) {
680
		pr_warn("%s: out of memory loading\n", a->name);
681 682 683 684 685 686 687 688 689 690
		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;
}

691
/* Module a uses b: caller needs module_mutex() */
692
int ref_module(struct module *a, struct module *b)
L
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693
{
694
	int err;
K
Kay Sievers 已提交
695

696
	if (b == NULL || already_uses(a, b))
697 698
		return 0;

699 700
	/* If module isn't available, we fail. */
	err = strong_try_module_get(b);
701
	if (err)
702
		return err;
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703

704 705
	err = add_module_usage(a, b);
	if (err) {
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706
		module_put(b);
707
		return err;
L
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708
	}
709
	return 0;
L
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710
}
711
EXPORT_SYMBOL_GPL(ref_module);
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/* Clear the unload stuff of the module. */
static void module_unload_free(struct module *mod)
{
716
	struct module_use *use, *tmp;
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717

718
	mutex_lock(&module_mutex);
719 720
	list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
		struct module *i = use->target;
721
		pr_debug("%s unusing %s\n", mod->name, i->name);
722 723 724 725
		module_put(i);
		list_del(&use->source_list);
		list_del(&use->target_list);
		kfree(use);
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726
	}
727
	mutex_unlock(&module_mutex);
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728 729 730
}

#ifdef CONFIG_MODULE_FORCE_UNLOAD
731
static inline int try_force_unload(unsigned int flags)
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732 733 734
{
	int ret = (flags & O_TRUNC);
	if (ret)
735
		add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
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736 737 738
	return ret;
}
#else
739
static inline int try_force_unload(unsigned int flags)
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740 741 742 743 744
{
	return 0;
}
#endif /* CONFIG_MODULE_FORCE_UNLOAD */

745 746
/* Try to release refcount of module, 0 means success. */
static int try_release_module_ref(struct module *mod)
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747
{
748
	int ret;
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749

750 751 752 753 754 755
	/* 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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756

757 758
	return ret;
}
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759

760 761
static int try_stop_module(struct module *mod, int flags, int *forced)
{
762
	/* If it's not unused, quit unless we're forcing. */
763 764 765
	if (try_release_module_ref(mod) != 0) {
		*forced = try_force_unload(flags);
		if (!(*forced))
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			return -EWOULDBLOCK;
	}

	/* Mark it as dying. */
770
	mod->state = MODULE_STATE_GOING;
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771

772
	return 0;
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773 774
}

775
unsigned long module_refcount(struct module *mod)
L
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776
{
777
	return (unsigned long)atomic_read(&mod->refcnt) - MODULE_REF_BASE;
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778 779 780 781 782 783
}
EXPORT_SYMBOL(module_refcount);

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

784 785
SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
		unsigned int, flags)
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786 787
{
	struct module *mod;
788
	char name[MODULE_NAME_LEN];
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789 790
	int ret, forced = 0;

791
	if (!capable(CAP_SYS_MODULE) || modules_disabled)
792 793 794 795 796 797
		return -EPERM;

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

798 799
	if (mutex_lock_interruptible(&module_mutex) != 0)
		return -EINTR;
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800 801 802 803 804 805 806

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

807
	if (!list_empty(&mod->source_list)) {
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808 809 810 811 812 813 814
		/* 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) {
815
		/* FIXME: if (force), slam module count damn the torpedoes */
816
		pr_debug("%s already dying\n", mod->name);
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817 818 819 820 821
		ret = -EBUSY;
		goto out;
	}

	/* If it has an init func, it must have an exit func to unload */
822
	if (mod->init && !mod->exit) {
823
		forced = try_force_unload(flags);
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824 825 826 827 828 829 830 831 832 833 834 835
		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;

836
	mutex_unlock(&module_mutex);
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837
	/* Final destruction now no one is using it. */
838
	if (mod->exit != NULL)
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839
		mod->exit();
840 841
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
842
	async_synchronize_full();
843

844
	/* Store the name of the last unloaded module for diagnostic purposes */
845
	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
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846

847 848 849
	free_module(mod);
	return 0;
out:
850
	mutex_unlock(&module_mutex);
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851 852 853
	return ret;
}

854
static inline void print_unload_info(struct seq_file *m, struct module *mod)
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855 856 857 858
{
	struct module_use *use;
	int printed_something = 0;

859
	seq_printf(m, " %lu ", module_refcount(mod));
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860

861 862 863 864
	/*
	 * Always include a trailing , so userspace can differentiate
	 * between this and the old multi-field proc format.
	 */
865
	list_for_each_entry(use, &mod->source_list, source_list) {
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866
		printed_something = 1;
867
		seq_printf(m, "%s,", use->source->name);
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868 869 870 871
	}

	if (mod->init != NULL && mod->exit == NULL) {
		printed_something = 1;
872
		seq_puts(m, "[permanent],");
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873 874 875
	}

	if (!printed_something)
876
		seq_puts(m, "-");
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877 878 879 880 881 882
}

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

883
	preempt_disable();
884
	if (!find_symbol(symbol, &owner, NULL, true, false))
L
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885 886
		BUG();
	module_put(owner);
887
	preempt_enable();
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888 889 890
}
EXPORT_SYMBOL(__symbol_put);

891
/* Note this assumes addr is a function, which it currently always is. */
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892 893
void symbol_put_addr(void *addr)
{
894
	struct module *modaddr;
895
	unsigned long a = (unsigned long)dereference_function_descriptor(addr);
L
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896

897
	if (core_kernel_text(a))
898
		return;
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899

900 901
	/* module_text_address is safe here: we're supposed to have reference
	 * to module from symbol_get, so it can't go away. */
902
	modaddr = __module_text_address(a);
903
	BUG_ON(!modaddr);
904
	module_put(modaddr);
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905 906 907 908
}
EXPORT_SYMBOL_GPL(symbol_put_addr);

static ssize_t show_refcnt(struct module_attribute *mattr,
909
			   struct module_kobject *mk, char *buffer)
L
Linus Torvalds 已提交
910
{
911
	return sprintf(buffer, "%lu\n", module_refcount(mk->mod));
L
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912 913
}

914 915
static struct module_attribute modinfo_refcnt =
	__ATTR(refcnt, 0444, show_refcnt, NULL);
L
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916

917 918 919 920
void __module_get(struct module *module)
{
	if (module) {
		preempt_disable();
921
		atomic_inc(&module->refcnt);
922 923 924 925 926 927 928 929 930 931 932 933
		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();
934 935 936
		/* Note: here, we can fail to get a reference */
		if (likely(module_is_live(module) &&
			   atomic_inc_not_zero(&module->refcnt) != 0))
937
			trace_module_get(module, _RET_IP_);
938
		else
939 940 941 942 943 944 945 946
			ret = false;

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

947 948
void module_put(struct module *module)
{
949 950
	int ret;

951
	if (module) {
952
		preempt_disable();
953 954
		ret = atomic_dec_if_positive(&module->refcnt);
		WARN_ON(ret < 0);	/* Failed to put refcount */
955
		trace_module_put(module, _RET_IP_);
956
		preempt_enable();
957 958 959 960
	}
}
EXPORT_SYMBOL(module_put);

L
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961
#else /* !CONFIG_MODULE_UNLOAD */
962
static inline void print_unload_info(struct seq_file *m, struct module *mod)
L
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963 964
{
	/* We don't know the usage count, or what modules are using. */
965
	seq_puts(m, " - -");
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966 967 968 969 970 971
}

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

972
int ref_module(struct module *a, struct module *b)
L
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973
{
974
	return strong_try_module_get(b);
L
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975
}
976
EXPORT_SYMBOL_GPL(ref_module);
L
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977

978
static inline int module_unload_init(struct module *mod)
L
Linus Torvalds 已提交
979
{
980
	return 0;
L
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981 982 983
}
#endif /* CONFIG_MODULE_UNLOAD */

984 985 986 987 988 989 990 991 992 993 994 995
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';
996
	if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
997
		buf[l++] = 'E';
998 999
	/*
	 * TAINT_FORCED_RMMOD: could be added.
1000
	 * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1001 1002 1003 1004 1005
	 * apply to modules.
	 */
	return l;
}

1006
static ssize_t show_initstate(struct module_attribute *mattr,
1007
			      struct module_kobject *mk, char *buffer)
1008 1009 1010
{
	const char *state = "unknown";

1011
	switch (mk->mod->state) {
1012 1013 1014 1015 1016 1017 1018 1019 1020
	case MODULE_STATE_LIVE:
		state = "live";
		break;
	case MODULE_STATE_COMING:
		state = "coming";
		break;
	case MODULE_STATE_GOING:
		state = "going";
		break;
1021 1022
	default:
		BUG();
1023 1024 1025 1026
	}
	return sprintf(buffer, "%s\n", state);
}

1027 1028
static struct module_attribute modinfo_initstate =
	__ATTR(initstate, 0444, show_initstate, NULL);
1029

1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040
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;
}

1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073
struct module_attribute module_uevent =
	__ATTR(uevent, 0200, NULL, store_uevent);

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

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

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

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

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

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

static struct module_attribute modinfo_taint =
	__ATTR(taint, 0444, show_taint, NULL);
1074

1075
static struct module_attribute *modinfo_attrs[] = {
1076
	&module_uevent,
1077 1078
	&modinfo_version,
	&modinfo_srcversion,
1079 1080 1081 1082
	&modinfo_initstate,
	&modinfo_coresize,
	&modinfo_initsize,
	&modinfo_taint,
1083
#ifdef CONFIG_MODULE_UNLOAD
1084
	&modinfo_refcnt,
1085 1086 1087 1088
#endif
	NULL,
};

L
Linus Torvalds 已提交
1089 1090
static const char vermagic[] = VERMAGIC_STRING;

1091
static int try_to_force_load(struct module *mod, const char *reason)
1092 1093
{
#ifdef CONFIG_MODULE_FORCE_LOAD
1094
	if (!test_taint(TAINT_FORCED_MODULE))
1095
		pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1096
	add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1097 1098 1099 1100 1101 1102
	return 0;
#else
	return -ENOEXEC;
#endif
}

L
Linus Torvalds 已提交
1103
#ifdef CONFIG_MODVERSIONS
1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114
/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
static unsigned long maybe_relocated(unsigned long crc,
				     const struct module *crc_owner)
{
#ifdef ARCH_RELOCATES_KCRCTAB
	if (crc_owner == NULL)
		return crc - (unsigned long)reloc_start;
#endif
	return crc;
}

L
Linus Torvalds 已提交
1115 1116 1117
static int check_version(Elf_Shdr *sechdrs,
			 unsigned int versindex,
			 const char *symname,
1118
			 struct module *mod,
1119 1120
			 const unsigned long *crc,
			 const struct module *crc_owner)
L
Linus Torvalds 已提交
1121 1122 1123 1124 1125 1126 1127 1128
{
	unsigned int i, num_versions;
	struct modversion_info *versions;

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

1129 1130 1131 1132
	/* No versions at all?  modprobe --force does this. */
	if (versindex == 0)
		return try_to_force_load(mod, symname) == 0;

L
Linus Torvalds 已提交
1133 1134 1135 1136 1137 1138 1139 1140
	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;

1141
		if (versions[i].crc == maybe_relocated(*crc, crc_owner))
L
Linus Torvalds 已提交
1142
			return 1;
1143
		pr_debug("Found checksum %lX vs module %lX\n",
1144
		       maybe_relocated(*crc, crc_owner), versions[i].crc);
1145
		goto bad_version;
L
Linus Torvalds 已提交
1146
	}
1147

1148
	pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1149
	return 0;
1150 1151

bad_version:
1152
	pr_warn("%s: disagrees about version of symbol %s\n",
1153 1154
	       mod->name, symname);
	return 0;
L
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1155 1156 1157 1158 1159 1160 1161 1162
}

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

1163 1164
	/* Since this should be found in kernel (which can't be removed),
	 * no locking is necessary. */
1165
	if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1166
			 &crc, true, false))
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Linus Torvalds 已提交
1167
		BUG();
1168 1169
	return check_version(sechdrs, versindex,
			     VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1170
			     NULL);
L
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1171 1172
}

1173 1174 1175
/* First part is kernel version, which we ignore if module has crcs. */
static inline int same_magic(const char *amagic, const char *bmagic,
			     bool has_crcs)
L
Linus Torvalds 已提交
1176
{
1177 1178 1179 1180
	if (has_crcs) {
		amagic += strcspn(amagic, " ");
		bmagic += strcspn(bmagic, " ");
	}
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1181 1182 1183 1184 1185 1186
	return strcmp(amagic, bmagic) == 0;
}
#else
static inline int check_version(Elf_Shdr *sechdrs,
				unsigned int versindex,
				const char *symname,
1187
				struct module *mod,
1188 1189
				const unsigned long *crc,
				const struct module *crc_owner)
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1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200
{
	return 1;
}

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

1201 1202
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 */

1208
/* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1209 1210
static const struct kernel_symbol *resolve_symbol(struct module *mod,
						  const struct load_info *info,
1211
						  const char *name,
1212
						  char ownername[])
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1213 1214
{
	struct module *owner;
1215
	const struct kernel_symbol *sym;
L
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1216
	const unsigned long *crc;
1217
	int err;
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1218

1219
	mutex_lock(&module_mutex);
1220
	sym = find_symbol(name, &owner, &crc,
1221
			  !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1222 1223 1224
	if (!sym)
		goto unlock;

1225 1226
	if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
			   owner)) {
1227 1228
		sym = ERR_PTR(-EINVAL);
		goto getname;
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1229
	}
1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240

	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:
1241
	mutex_unlock(&module_mutex);
1242
	return sym;
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1243 1244
}

1245 1246 1247 1248
static const struct kernel_symbol *
resolve_symbol_wait(struct module *mod,
		    const struct load_info *info,
		    const char *name)
1249 1250
{
	const struct kernel_symbol *ksym;
1251
	char owner[MODULE_NAME_LEN];
1252 1253

	if (wait_event_interruptible_timeout(module_wq,
1254 1255
			!IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
			|| PTR_ERR(ksym) != -EBUSY,
1256
					     30 * HZ) <= 0) {
1257 1258
		pr_warn("%s: gave up waiting for init of module %s.\n",
			mod->name, owner);
1259 1260 1261 1262
	}
	return ksym;
}

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/*
 * /sys/module/foo/sections stuff
 * J. Corbet <corbet@lwn.net>
 */
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1267
#ifdef CONFIG_SYSFS
1268

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#ifdef CONFIG_KALLSYMS
1270 1271 1272 1273 1274
static inline bool sect_empty(const Elf_Shdr *sect)
{
	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
}

1275
struct module_sect_attr {
1276 1277 1278 1279 1280
	struct module_attribute mattr;
	char *name;
	unsigned long address;
};

1281
struct module_sect_attrs {
1282 1283 1284 1285 1286
	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,
1288
				struct module_kobject *mk, char *buf)
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1289 1290 1291
{
	struct module_sect_attr *sattr =
		container_of(mattr, struct module_sect_attr, mattr);
1292
	return sprintf(buf, "0x%pK\n", (void *)sattr->address);
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}

1295 1296
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
1297
	unsigned int section;
1298 1299 1300 1301 1302 1303

	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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1305 1306 1307 1308 1309
{
	unsigned int nloaded = 0, i, size[2];
	struct module_sect_attrs *sect_attrs;
	struct module_sect_attr *sattr;
	struct attribute **gattr;
1310

L
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1311
	/* Count loaded sections and allocate structures */
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1312 1313
	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]))
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1314 1315 1316 1317 1318
			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]);
1319 1320
	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
	if (sect_attrs == NULL)
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1321 1322 1323 1324 1325 1326
		return;

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

1327
	sect_attrs->nsections = 0;
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1328 1329
	sattr = &sect_attrs->attrs[0];
	gattr = &sect_attrs->grp.attrs[0];
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1330 1331 1332
	for (i = 0; i < info->hdr->e_shnum; i++) {
		Elf_Shdr *sec = &info->sechdrs[i];
		if (sect_empty(sec))
1333
			continue;
R
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1334 1335
		sattr->address = sec->sh_addr;
		sattr->name = kstrdup(info->secstrings + sec->sh_name,
1336 1337 1338 1339
					GFP_KERNEL);
		if (sattr->name == NULL)
			goto out;
		sect_attrs->nsections++;
1340
		sysfs_attr_init(&sattr->mattr.attr);
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1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354
		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:
1355
	free_sect_attrs(sect_attrs);
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1356 1357 1358 1359 1360 1361 1362 1363 1364
}

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. */
1365
		free_sect_attrs(mod->sect_attrs);
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		mod->sect_attrs = NULL;
	}
}

1370 1371 1372 1373 1374 1375 1376 1377 1378 1379
/*
 * /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];
};

1380
static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397
				 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]);
1398
		kobject_put(notes_attrs->dir);
1399 1400 1401 1402
	}
	kfree(notes_attrs);
}

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static void add_notes_attrs(struct module *mod, const struct load_info *info)
1404 1405 1406 1407 1408
{
	unsigned int notes, loaded, i;
	struct module_notes_attrs *notes_attrs;
	struct bin_attribute *nattr;

1409 1410 1411 1412
	/* failed to create section attributes, so can't create notes */
	if (!mod->sect_attrs)
		return;

1413 1414
	/* Count notes sections and allocate structures.  */
	notes = 0;
R
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1415 1416 1417
	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]) &&
		    (info->sechdrs[i].sh_type == SHT_NOTE))
1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430
			++notes;

	if (notes == 0)
		return;

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

	notes_attrs->notes = notes;
	nattr = &notes_attrs->attrs[0];
R
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1431 1432
	for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
		if (sect_empty(&info->sechdrs[i]))
1433
			continue;
R
Rusty Russell 已提交
1434
		if (info->sechdrs[i].sh_type == SHT_NOTE) {
1435
			sysfs_bin_attr_init(nattr);
1436 1437
			nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
			nattr->attr.mode = S_IRUGO;
R
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1438 1439
			nattr->size = info->sechdrs[i].sh_size;
			nattr->private = (void *) info->sechdrs[i].sh_addr;
1440 1441 1442 1443 1444 1445
			nattr->read = module_notes_read;
			++nattr;
		}
		++loaded;
	}

1446
	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467
	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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1468
#else
1469

R
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1470 1471
static inline void add_sect_attrs(struct module *mod,
				  const struct load_info *info)
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1472 1473 1474 1475 1476 1477
{
}

static inline void remove_sect_attrs(struct module *mod)
{
}
1478

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1479 1480
static inline void add_notes_attrs(struct module *mod,
				   const struct load_info *info)
1481 1482 1483 1484 1485 1486
{
}

static inline void remove_notes_attrs(struct module *mod)
{
}
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1487
#endif /* CONFIG_KALLSYMS */
L
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1488

1489 1490 1491 1492 1493 1494
static void add_usage_links(struct module *mod)
{
#ifdef CONFIG_MODULE_UNLOAD
	struct module_use *use;
	int nowarn;

1495
	mutex_lock(&module_mutex);
1496 1497 1498 1499
	list_for_each_entry(use, &mod->target_list, target_list) {
		nowarn = sysfs_create_link(use->target->holders_dir,
					   &mod->mkobj.kobj, mod->name);
	}
1500
	mutex_unlock(&module_mutex);
1501 1502 1503 1504 1505 1506 1507 1508
#endif
}

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

1509
	mutex_lock(&module_mutex);
1510 1511
	list_for_each_entry(use, &mod->target_list, target_list)
		sysfs_remove_link(use->target->holders_dir, mod->name);
1512
	mutex_unlock(&module_mutex);
1513 1514 1515
#endif
}

1516
static int module_add_modinfo_attrs(struct module *mod)
1517 1518
{
	struct module_attribute *attr;
1519
	struct module_attribute *temp_attr;
1520 1521 1522
	int error = 0;
	int i;

1523 1524 1525 1526 1527 1528 1529
	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;
1530 1531
	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
		if (!attr->test ||
1532 1533
		    (attr->test && attr->test(mod))) {
			memcpy(temp_attr, attr, sizeof(*temp_attr));
1534
			sysfs_attr_init(&temp_attr->attr);
1535 1536
			error = sysfs_create_file(&mod->mkobj.kobj,
					&temp_attr->attr);
1537 1538
			++temp_attr;
		}
1539 1540 1541 1542
	}
	return error;
}

1543
static void module_remove_modinfo_attrs(struct module *mod)
1544 1545 1546 1547
{
	struct module_attribute *attr;
	int i;

1548 1549 1550 1551
	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
		/* pick a field to test for end of list */
		if (!attr->attr.name)
			break;
1552
		sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1553 1554
		if (attr->free)
			attr->free(mod);
1555
	}
1556
	kfree(mod->modinfo_attrs);
1557
}
L
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1558

1559 1560 1561 1562 1563 1564 1565 1566
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);
}

1567
static int mod_sysfs_init(struct module *mod)
L
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1568 1569
{
	int err;
1570
	struct kobject *kobj;
L
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1571

1572
	if (!module_sysfs_initialized) {
1573
		pr_err("%s: module sysfs not initialized\n", mod->name);
1574 1575 1576
		err = -EINVAL;
		goto out;
	}
1577 1578 1579

	kobj = kset_find_obj(module_kset, mod->name);
	if (kobj) {
1580
		pr_err("%s: module is already loaded\n", mod->name);
1581 1582 1583 1584 1585
		kobject_put(kobj);
		err = -EINVAL;
		goto out;
	}

L
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1586
	mod->mkobj.mod = mod;
1587

1588 1589 1590 1591 1592
	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)
1593
		mod_kobject_put(mod);
K
Kay Sievers 已提交
1594

1595
	/* delay uevent until full sysfs population */
K
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1596 1597 1598 1599
out:
	return err;
}

1600
static int mod_sysfs_setup(struct module *mod,
R
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1601
			   const struct load_info *info,
K
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1602 1603 1604 1605 1606
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	int err;

1607 1608 1609 1610
	err = mod_sysfs_init(mod);
	if (err)
		goto out;

1611
	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1612 1613
	if (!mod->holders_dir) {
		err = -ENOMEM;
K
Kay Sievers 已提交
1614
		goto out_unreg;
1615
	}
K
Kay Sievers 已提交
1616

L
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1617 1618
	err = module_param_sysfs_setup(mod, kparam, num_params);
	if (err)
K
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1619
		goto out_unreg_holders;
L
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1620

1621 1622
	err = module_add_modinfo_attrs(mod);
	if (err)
1623
		goto out_unreg_param;
1624

1625
	add_usage_links(mod);
R
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1626 1627
	add_sect_attrs(mod, info);
	add_notes_attrs(mod, info);
1628

1629
	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
L
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1630 1631
	return 0;

1632 1633
out_unreg_param:
	module_param_sysfs_remove(mod);
K
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1634
out_unreg_holders:
1635
	kobject_put(mod->holders_dir);
K
Kay Sievers 已提交
1636
out_unreg:
1637
	mod_kobject_put(mod);
1638
out:
L
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1639 1640
	return err;
}
1641 1642 1643

static void mod_sysfs_fini(struct module *mod)
{
R
Rusty Russell 已提交
1644 1645
	remove_notes_attrs(mod);
	remove_sect_attrs(mod);
1646
	mod_kobject_put(mod);
1647 1648
}

R
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1649
#else /* !CONFIG_SYSFS */
1650

R
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1651 1652
static int mod_sysfs_setup(struct module *mod,
			   const struct load_info *info,
1653 1654 1655 1656 1657 1658
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	return 0;
}

1659 1660 1661 1662
static void mod_sysfs_fini(struct module *mod)
{
}

1663 1664 1665 1666
static void module_remove_modinfo_attrs(struct module *mod)
{
}

1667 1668 1669 1670
static void del_usage_links(struct module *mod)
{
}

1671
#endif /* CONFIG_SYSFS */
L
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1672

1673
static void mod_sysfs_teardown(struct module *mod)
L
Linus Torvalds 已提交
1674
{
1675
	del_usage_links(mod);
1676
	module_remove_modinfo_attrs(mod);
L
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1677
	module_param_sysfs_remove(mod);
1678 1679
	kobject_put(mod->mkobj.drivers_dir);
	kobject_put(mod->holders_dir);
1680
	mod_sysfs_fini(mod);
L
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1681 1682
}

1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726
#ifdef CONFIG_DEBUG_SET_MODULE_RONX
/*
 * LKM RO/NX protection: protect module's text/ro-data
 * from modification and any data from execution.
 */
void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
{
	unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
	unsigned long end_pfn = PFN_DOWN((unsigned long)end);

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

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

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

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

1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744
static void unset_module_core_ro_nx(struct module *mod)
{
	set_page_attributes(mod->module_core + mod->core_text_size,
		mod->module_core + mod->core_size,
		set_memory_x);
	set_page_attributes(mod->module_core,
		mod->module_core + mod->core_ro_size,
		set_memory_rw);
}

static void unset_module_init_ro_nx(struct module *mod)
{
	set_page_attributes(mod->module_init + mod->init_text_size,
		mod->module_init + mod->init_size,
		set_memory_x);
	set_page_attributes(mod->module_init,
		mod->module_init + mod->init_ro_size,
		set_memory_rw);
1745 1746 1747
}

/* Iterate through all modules and set each module's text as RW */
1748
void set_all_modules_text_rw(void)
1749 1750 1751 1752 1753
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1754 1755
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770
		if ((mod->module_core) && (mod->core_text_size)) {
			set_page_attributes(mod->module_core,
						mod->module_core + mod->core_text_size,
						set_memory_rw);
		}
		if ((mod->module_init) && (mod->init_text_size)) {
			set_page_attributes(mod->module_init,
						mod->module_init + mod->init_text_size,
						set_memory_rw);
		}
	}
	mutex_unlock(&module_mutex);
}

/* Iterate through all modules and set each module's text as RO */
1771
void set_all_modules_text_ro(void)
1772 1773 1774 1775 1776
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1777 1778
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793
		if ((mod->module_core) && (mod->core_text_size)) {
			set_page_attributes(mod->module_core,
						mod->module_core + mod->core_text_size,
						set_memory_ro);
		}
		if ((mod->module_init) && (mod->init_text_size)) {
			set_page_attributes(mod->module_init,
						mod->module_init + mod->init_text_size,
						set_memory_ro);
		}
	}
	mutex_unlock(&module_mutex);
}
#else
static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1794 1795
static void unset_module_core_ro_nx(struct module *mod) { }
static void unset_module_init_ro_nx(struct module *mod) { }
1796 1797
#endif

1798 1799 1800 1801 1802 1803 1804 1805 1806
void __weak module_free(struct module *mod, void *module_region)
{
	vfree(module_region);
}

void __weak module_arch_cleanup(struct module *mod)
{
}

1807 1808 1809 1810
void __weak module_arch_freeing_init(struct module *mod)
{
}

1811
/* Free a module, remove from lists, etc. */
L
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1812 1813
static void free_module(struct module *mod)
{
1814 1815
	trace_module_free(mod);

1816
	mod_sysfs_teardown(mod);
L
Linus Torvalds 已提交
1817

1818 1819
	/* We leave it in list to prevent duplicate loads, but make sure
	 * that noone uses it while it's being deconstructed. */
1820
	mutex_lock(&module_mutex);
1821
	mod->state = MODULE_STATE_UNFORMED;
1822
	mutex_unlock(&module_mutex);
1823

1824 1825 1826
	/* Remove dynamic debug info */
	ddebug_remove_module(mod->name);

L
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1827 1828 1829 1830 1831 1832
	/* Arch-specific cleanup. */
	module_arch_cleanup(mod);

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

1833 1834 1835
	/* Free any allocated parameters. */
	destroy_params(mod->kp, mod->num_kp);

1836 1837
	/* Now we can delete it from the lists */
	mutex_lock(&module_mutex);
1838 1839
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
1840
	/* Remove this module from bug list, this uses list_del_rcu */
1841
	module_bug_cleanup(mod);
1842 1843
	/* Wait for RCU synchronizing before releasing mod->list and buglist. */
	synchronize_rcu();
1844 1845
	mutex_unlock(&module_mutex);

L
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1846
	/* This may be NULL, but that's OK */
1847
	unset_module_init_ro_nx(mod);
1848
	module_arch_freeing_init(mod);
L
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1849 1850
	module_free(mod, mod->module_init);
	kfree(mod->args);
1851
	percpu_modfree(mod);
1852

I
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1853 1854 1855
	/* Free lock-classes: */
	lockdep_free_key_range(mod->module_core, mod->core_size);

L
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1856
	/* Finally, free the core (containing the module structure) */
1857
	unset_module_core_ro_nx(mod);
L
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1858
	module_free(mod, mod->module_core);
1859 1860 1861 1862

#ifdef CONFIG_MPU
	update_protections(current->mm);
#endif
L
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1863 1864 1865 1866 1867
}

void *__symbol_get(const char *symbol)
{
	struct module *owner;
1868
	const struct kernel_symbol *sym;
L
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1869

1870
	preempt_disable();
1871 1872 1873
	sym = find_symbol(symbol, &owner, NULL, true, true);
	if (sym && strong_try_module_get(owner))
		sym = NULL;
1874
	preempt_enable();
L
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1875

1876
	return sym ? (void *)sym->value : NULL;
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1877 1878 1879
}
EXPORT_SYMBOL_GPL(__symbol_get);

1880 1881
/*
 * Ensure that an exported symbol [global namespace] does not already exist
1882
 * in the kernel or in some other module's exported symbol table.
1883 1884
 *
 * You must hold the module_mutex.
1885 1886 1887
 */
static int verify_export_symbols(struct module *mod)
{
1888
	unsigned int i;
1889
	struct module *owner;
1890 1891 1892 1893 1894 1895 1896 1897
	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 },
1898
#ifdef CONFIG_UNUSED_SYMBOLS
1899 1900
		{ mod->unused_syms, mod->num_unused_syms },
		{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1901
#endif
1902
	};
1903

1904 1905
	for (i = 0; i < ARRAY_SIZE(arr); i++) {
		for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1906
			if (find_symbol(s->name, &owner, NULL, true, false)) {
1907
				pr_err("%s: exports duplicate symbol %s"
1908 1909 1910 1911
				       " (owned by %s)\n",
				       mod->name, s->name, module_name(owner));
				return -ENOEXEC;
			}
1912
		}
1913 1914
	}
	return 0;
1915 1916
}

1917
/* Change all symbols so that st_value encodes the pointer directly. */
1918 1919 1920 1921
static int simplify_symbols(struct module *mod, const struct load_info *info)
{
	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
	Elf_Sym *sym = (void *)symsec->sh_addr;
L
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1922
	unsigned long secbase;
1923
	unsigned int i;
L
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1924
	int ret = 0;
1925
	const struct kernel_symbol *ksym;
L
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1926

1927 1928 1929
	for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
		const char *name = info->strtab + sym[i].st_name;

L
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1930 1931
		switch (sym[i].st_shndx) {
		case SHN_COMMON:
1932 1933 1934 1935
			/* Ignore common symbols */
			if (!strncmp(name, "__gnu_lto", 9))
				break;

L
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1936 1937
			/* We compiled with -fno-common.  These are not
			   supposed to happen.  */
1938
			pr_debug("Common symbol: %s\n", name);
1939
			pr_warn("%s: please compile with -fno-common\n",
L
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1940 1941 1942 1943 1944 1945
			       mod->name);
			ret = -ENOEXEC;
			break;

		case SHN_ABS:
			/* Don't need to do anything */
1946
			pr_debug("Absolute symbol: 0x%08lx\n",
L
Linus Torvalds 已提交
1947 1948 1949 1950
			       (long)sym[i].st_value);
			break;

		case SHN_UNDEF:
1951
			ksym = resolve_symbol_wait(mod, info, name);
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			/* Ok if resolved.  */
1953
			if (ksym && !IS_ERR(ksym)) {
1954
				sym[i].st_value = ksym->value;
L
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1955
				break;
1956 1957
			}

L
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1958
			/* Ok if weak.  */
1959
			if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
L
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1960 1961
				break;

1962 1963
			pr_warn("%s: Unknown symbol %s (err %li)\n",
				mod->name, name, PTR_ERR(ksym));
1964
			ret = PTR_ERR(ksym) ?: -ENOENT;
L
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1965 1966 1967 1968
			break;

		default:
			/* Divert to percpu allocation if a percpu var. */
1969
			if (sym[i].st_shndx == info->index.pcpu)
1970
				secbase = (unsigned long)mod_percpu(mod);
L
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1971
			else
1972
				secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
L
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1973 1974 1975 1976 1977 1978 1979 1980
			sym[i].st_value += secbase;
			break;
		}
	}

	return ret;
}

1981
static int apply_relocations(struct module *mod, const struct load_info *info)
1982 1983 1984 1985 1986
{
	unsigned int i;
	int err = 0;

	/* Now do relocations. */
1987 1988
	for (i = 1; i < info->hdr->e_shnum; i++) {
		unsigned int infosec = info->sechdrs[i].sh_info;
1989 1990

		/* Not a valid relocation section? */
1991
		if (infosec >= info->hdr->e_shnum)
1992 1993 1994
			continue;

		/* Don't bother with non-allocated sections */
1995
		if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1996 1997
			continue;

1998 1999 2000 2001 2002 2003
		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);
2004 2005 2006 2007 2008 2009
		if (err < 0)
			break;
	}
	return err;
}

2010 2011 2012 2013 2014 2015 2016 2017
/* Additional bytes needed by arch in front of individual sections */
unsigned int __weak arch_mod_section_prepend(struct module *mod,
					     unsigned int section)
{
	/* default implementation just returns zero */
	return 0;
}

L
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2018
/* Update size with this section: return offset. */
2019 2020
static long get_offset(struct module *mod, unsigned int *size,
		       Elf_Shdr *sechdr, unsigned int section)
L
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2021 2022 2023
{
	long ret;

2024
	*size += arch_mod_section_prepend(mod, section);
L
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2025 2026 2027 2028 2029 2030 2031 2032 2033
	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. */
2034
static void layout_sections(struct module *mod, struct load_info *info)
L
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2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046
{
	static unsigned long const masks[][2] = {
		/* NOTE: all executable code must be the first section
		 * in this array; otherwise modify the text_size
		 * finder in the two loops below */
		{ SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
		{ SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
		{ SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
		{ ARCH_SHF_SMALL | SHF_ALLOC, 0 }
	};
	unsigned int m, i;

2047 2048
	for (i = 0; i < info->hdr->e_shnum; i++)
		info->sechdrs[i].sh_entsize = ~0UL;
L
Linus Torvalds 已提交
2049

2050
	pr_debug("Core section allocation order:\n");
L
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2051
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2052 2053 2054
		for (i = 0; i < info->hdr->e_shnum; ++i) {
			Elf_Shdr *s = &info->sechdrs[i];
			const char *sname = info->secstrings + s->sh_name;
L
Linus Torvalds 已提交
2055 2056 2057 2058

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2059
			    || strstarts(sname, ".init"))
L
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2060
				continue;
2061
			s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2062
			pr_debug("\t%s\n", sname);
L
Linus Torvalds 已提交
2063
		}
2064 2065 2066
		switch (m) {
		case 0: /* executable */
			mod->core_size = debug_align(mod->core_size);
L
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2067
			mod->core_text_size = mod->core_size;
2068 2069 2070 2071 2072 2073 2074 2075 2076
			break;
		case 1: /* RO: text and ro-data */
			mod->core_size = debug_align(mod->core_size);
			mod->core_ro_size = mod->core_size;
			break;
		case 3: /* whole core */
			mod->core_size = debug_align(mod->core_size);
			break;
		}
L
Linus Torvalds 已提交
2077 2078
	}

2079
	pr_debug("Init section allocation order:\n");
L
Linus Torvalds 已提交
2080
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2081 2082 2083
		for (i = 0; i < info->hdr->e_shnum; ++i) {
			Elf_Shdr *s = &info->sechdrs[i];
			const char *sname = info->secstrings + s->sh_name;
L
Linus Torvalds 已提交
2084 2085 2086 2087

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2088
			    || !strstarts(sname, ".init"))
L
Linus Torvalds 已提交
2089
				continue;
2090
			s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
L
Linus Torvalds 已提交
2091
					 | INIT_OFFSET_MASK);
2092
			pr_debug("\t%s\n", sname);
L
Linus Torvalds 已提交
2093
		}
2094 2095 2096
		switch (m) {
		case 0: /* executable */
			mod->init_size = debug_align(mod->init_size);
L
Linus Torvalds 已提交
2097
			mod->init_text_size = mod->init_size;
2098 2099 2100 2101 2102 2103 2104 2105 2106
			break;
		case 1: /* RO: text and ro-data */
			mod->init_size = debug_align(mod->init_size);
			mod->init_ro_size = mod->init_size;
			break;
		case 3: /* whole init */
			mod->init_size = debug_align(mod->init_size);
			break;
		}
L
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2107 2108 2109 2110 2111 2112 2113 2114
	}
}

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

2115
	if (!license_is_gpl_compatible(license)) {
2116
		if (!test_taint(TAINT_PROPRIETARY_MODULE))
2117 2118
			pr_warn("%s: module license '%s' taints kernel.\n",
				mod->name, license);
2119 2120
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
L
Linus Torvalds 已提交
2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142
	}
}

/* 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;
}

2143
static char *get_modinfo(struct load_info *info, const char *tag)
L
Linus Torvalds 已提交
2144 2145 2146
{
	char *p;
	unsigned int taglen = strlen(tag);
2147 2148
	Elf_Shdr *infosec = &info->sechdrs[info->index.info];
	unsigned long size = infosec->sh_size;
L
Linus Torvalds 已提交
2149

2150
	for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
L
Linus Torvalds 已提交
2151 2152 2153 2154 2155 2156
		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
			return p + taglen + 1;
	}
	return NULL;
}

2157
static void setup_modinfo(struct module *mod, struct load_info *info)
2158 2159 2160 2161 2162 2163
{
	struct module_attribute *attr;
	int i;

	for (i = 0; (attr = modinfo_attrs[i]); i++) {
		if (attr->setup)
2164
			attr->setup(mod, get_modinfo(info, attr->attr.name));
2165 2166 2167
	}
}

2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178
static void free_modinfo(struct module *mod)
{
	struct module_attribute *attr;
	int i;

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

L
Linus Torvalds 已提交
2179
#ifdef CONFIG_KALLSYMS
2180 2181 2182 2183 2184 2185

/* 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)
{
2186 2187
	return bsearch(name, start, stop - start,
			sizeof(struct kernel_symbol), cmp_name);
2188 2189
}

2190 2191
static int is_exported(const char *name, unsigned long value,
		       const struct module *mod)
L
Linus Torvalds 已提交
2192
{
2193 2194 2195
	const struct kernel_symbol *ks;
	if (!mod)
		ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2196
	else
2197 2198
		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
	return ks != NULL && ks->value == value;
L
Linus Torvalds 已提交
2199 2200 2201
}

/* As per nm */
2202
static char elf_type(const Elf_Sym *sym, const struct load_info *info)
L
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2203
{
2204 2205
	const Elf_Shdr *sechdrs = info->sechdrs;

L
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2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234
	if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
		if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
			return 'v';
		else
			return 'w';
	}
	if (sym->st_shndx == SHN_UNDEF)
		return 'U';
	if (sym->st_shndx == SHN_ABS)
		return 'a';
	if (sym->st_shndx >= SHN_LORESERVE)
		return '?';
	if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
		return 't';
	if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
	    && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
		if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
			return 'r';
		else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
			return 'g';
		else
			return 'd';
	}
	if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
		if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
			return 's';
		else
			return 'b';
	}
2235 2236
	if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
		      ".debug")) {
L
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2237
		return 'n';
2238
	}
L
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2239 2240 2241
	return '?';
}

2242
static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2243
			unsigned int shnum)
2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262
{
	const Elf_Shdr *sec;

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

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

	return true;
}

2263 2264 2265 2266 2267 2268 2269
/*
 * 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>.
 */
2270
static void layout_symtab(struct module *mod, struct load_info *info)
2271
{
2272 2273
	Elf_Shdr *symsect = info->sechdrs + info->index.sym;
	Elf_Shdr *strsect = info->sechdrs + info->index.str;
2274
	const Elf_Sym *src;
2275
	unsigned int i, nsrc, ndst, strtab_size = 0;
2276 2277 2278 2279

	/* Put symbol section at end of init part of module. */
	symsect->sh_flags |= SHF_ALLOC;
	symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2280
					 info->index.sym) | INIT_OFFSET_MASK;
2281
	pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2282

2283
	src = (void *)info->hdr + symsect->sh_offset;
2284
	nsrc = symsect->sh_size / sizeof(*src);
2285

2286
	/* Compute total space required for the core symbols' strtab. */
2287 2288 2289 2290
	for (ndst = i = 0; i < nsrc; i++) {
		if (i == 0 ||
		    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
			strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2291
			ndst++;
2292
		}
2293
	}
2294 2295

	/* Append room for core symbols at end of core part. */
2296
	info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2297 2298
	info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
	mod->core_size += strtab_size;
2299

2300 2301 2302
	/* Put string table section at end of init part of module. */
	strsect->sh_flags |= SHF_ALLOC;
	strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2303
					 info->index.str) | INIT_OFFSET_MASK;
2304
	pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2305 2306
}

2307
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2308
{
2309 2310 2311
	unsigned int i, ndst;
	const Elf_Sym *src;
	Elf_Sym *dst;
2312
	char *s;
2313
	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
L
Linus Torvalds 已提交
2314

2315 2316
	mod->symtab = (void *)symsec->sh_addr;
	mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2317 2318
	/* Make sure we get permanent strtab: don't use info->strtab. */
	mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
L
Linus Torvalds 已提交
2319 2320 2321

	/* Set types up while we still have access to sections. */
	for (i = 0; i < mod->num_symtab; i++)
2322
		mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2323

2324
	mod->core_symtab = dst = mod->module_core + info->symoffs;
2325
	mod->core_strtab = s = mod->module_core + info->stroffs;
2326
	src = mod->symtab;
2327 2328 2329 2330 2331 2332 2333 2334
	for (ndst = i = 0; i < mod->num_symtab; i++) {
		if (i == 0 ||
		    is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
			dst[ndst] = src[i];
			dst[ndst++].st_name = s - mod->core_strtab;
			s += strlcpy(s, &mod->strtab[src[i].st_name],
				     KSYM_NAME_LEN) + 1;
		}
2335 2336
	}
	mod->core_num_syms = ndst;
L
Linus Torvalds 已提交
2337 2338
}
#else
2339
static inline void layout_symtab(struct module *mod, struct load_info *info)
2340 2341
{
}
2342

2343
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2344 2345 2346 2347
{
}
#endif /* CONFIG_KALLSYMS */

2348
static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2349
{
2350 2351
	if (!debug)
		return;
2352 2353
#ifdef CONFIG_DYNAMIC_DEBUG
	if (ddebug_add_module(debug, num, debug->modname))
2354 2355
		pr_err("dynamic debug error adding module: %s\n",
			debug->modname);
2356
#endif
2357
}
2358

2359 2360 2361 2362 2363 2364
static void dynamic_debug_remove(struct _ddebug *debug)
{
	if (debug)
		ddebug_remove_module(debug->modname);
}

2365 2366
void * __weak module_alloc(unsigned long size)
{
2367
	return vmalloc_exec(size);
2368 2369
}

2370 2371 2372 2373 2374
static void *module_alloc_update_bounds(unsigned long size)
{
	void *ret = module_alloc(size);

	if (ret) {
2375
		mutex_lock(&module_mutex);
2376 2377 2378 2379 2380
		/* Update module bounds. */
		if ((unsigned long)ret < module_addr_min)
			module_addr_min = (unsigned long)ret;
		if ((unsigned long)ret + size > module_addr_max)
			module_addr_max = (unsigned long)ret + size;
2381
		mutex_unlock(&module_mutex);
2382 2383 2384 2385
	}
	return ret;
}

2386
#ifdef CONFIG_DEBUG_KMEMLEAK
2387 2388
static void kmemleak_load_module(const struct module *mod,
				 const struct load_info *info)
2389 2390 2391 2392
{
	unsigned int i;

	/* only scan the sections containing data */
2393
	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2394

2395
	for (i = 1; i < info->hdr->e_shnum; i++) {
2396 2397 2398 2399
		/* 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))
2400 2401
			continue;

2402 2403
		kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
				   info->sechdrs[i].sh_size, GFP_KERNEL);
2404 2405 2406
	}
}
#else
2407 2408
static inline void kmemleak_load_module(const struct module *mod,
					const struct load_info *info)
2409 2410 2411 2412
{
}
#endif

2413
#ifdef CONFIG_MODULE_SIG
2414
static int module_sig_check(struct load_info *info)
2415 2416
{
	int err = -ENOKEY;
2417 2418
	const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
	const void *mod = info->hdr;
2419

2420 2421
	if (info->len > markerlen &&
	    memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2422
		/* We truncate the module to discard the signature */
2423 2424
		info->len -= markerlen;
		err = mod_verify_sig(mod, &info->len);
2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438
	}

	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 */
2439
static int module_sig_check(struct load_info *info)
2440 2441 2442 2443 2444
{
	return 0;
}
#endif /* !CONFIG_MODULE_SIG */

2445 2446
/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
static int elf_header_check(struct load_info *info)
2447
{
2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460
	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;
2461

2462 2463 2464 2465 2466 2467
	return 0;
}

/* Sets info->hdr and info->len. */
static int copy_module_from_user(const void __user *umod, unsigned long len,
				  struct load_info *info)
2468 2469 2470
{
	int err;

2471 2472
	info->len = len;
	if (info->len < sizeof(*(info->hdr)))
2473 2474
		return -ENOEXEC;

2475 2476 2477 2478
	err = security_kernel_module_from_file(NULL);
	if (err)
		return err;

2479
	/* Suck in entire file: we'll want most of it. */
2480 2481
	info->hdr = vmalloc(info->len);
	if (!info->hdr)
2482 2483
		return -ENOMEM;

2484 2485 2486
	if (copy_from_user(info->hdr, umod, info->len) != 0) {
		vfree(info->hdr);
		return -EFAULT;
2487 2488
	}

2489 2490 2491 2492 2493 2494
	return 0;
}

/* Sets info->hdr and info->len. */
static int copy_module_from_fd(int fd, struct load_info *info)
{
2495
	struct fd f = fdget(fd);
2496 2497 2498 2499 2500
	int err;
	struct kstat stat;
	loff_t pos;
	ssize_t bytes = 0;

2501
	if (!f.file)
2502 2503
		return -ENOEXEC;

2504
	err = security_kernel_module_from_file(f.file);
2505
	if (err)
2506
		goto out;
2507

2508
	err = vfs_getattr(&f.file->f_path, &stat);
2509
	if (err)
2510
		goto out;
2511

2512 2513 2514
	if (stat.size > INT_MAX) {
		err = -EFBIG;
		goto out;
2515
	}
2516 2517 2518 2519 2520 2521 2522

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

2523 2524 2525 2526
	info->hdr = vmalloc(stat.size);
	if (!info->hdr) {
		err = -ENOMEM;
		goto out;
2527
	}
2528

2529 2530
	pos = 0;
	while (pos < stat.size) {
2531
		bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542
				    stat.size - pos);
		if (bytes < 0) {
			vfree(info->hdr);
			err = bytes;
			goto out;
		}
		if (bytes == 0)
			break;
		pos += bytes;
	}
	info->len = pos;
2543

2544
out:
2545
	fdput(f);
2546 2547 2548
	return err;
}

2549 2550 2551 2552 2553
static void free_copy(struct load_info *info)
{
	vfree(info->hdr);
}

2554
static int rewrite_section_headers(struct load_info *info, int flags)
2555 2556 2557 2558 2559 2560 2561 2562 2563 2564
{
	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) {
2565
			pr_err("Module len %lu truncated\n", info->len);
2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578
			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
	}
2579 2580

	/* Track but don't keep modinfo and version sections. */
2581 2582 2583 2584
	if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
		info->index.vers = 0; /* Pretend no __versions section! */
	else
		info->index.vers = find_sec(info, "__versions");
2585
	info->index.info = find_sec(info, ".modinfo");
2586 2587
	info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
	info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2588 2589 2590
	return 0;
}

L
Linus Torvalds 已提交
2591 2592 2593 2594 2595 2596 2597 2598
/*
 * 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).
 */
2599
static struct module *setup_load_info(struct load_info *info, int flags)
L
Linus Torvalds 已提交
2600 2601
{
	unsigned int i;
2602
	int err;
L
Linus Torvalds 已提交
2603 2604 2605 2606
	struct module *mod;

	/* Set up the convenience variables */
	info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2607 2608
	info->secstrings = (void *)info->hdr
		+ info->sechdrs[info->hdr->e_shstrndx].sh_offset;
L
Linus Torvalds 已提交
2609

2610
	err = rewrite_section_headers(info, flags);
2611 2612
	if (err)
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2613

2614 2615
	/* Find internal symbols and strings. */
	for (i = 1; i < info->hdr->e_shnum; i++) {
L
Linus Torvalds 已提交
2616 2617 2618
		if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
			info->index.sym = i;
			info->index.str = info->sechdrs[i].sh_link;
2619 2620 2621
			info->strtab = (char *)info->hdr
				+ info->sechdrs[info->index.str].sh_offset;
			break;
L
Linus Torvalds 已提交
2622 2623 2624
		}
	}

2625
	info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
L
Linus Torvalds 已提交
2626
	if (!info->index.mod) {
2627
		pr_warn("No module found in object\n");
L
Linus Torvalds 已提交
2628 2629 2630 2631 2632 2633
		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) {
2634
		pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
L
Linus Torvalds 已提交
2635 2636 2637
		return ERR_PTR(-ENOEXEC);
	}

2638
	info->index.pcpu = find_pcpusec(info);
L
Linus Torvalds 已提交
2639 2640 2641 2642 2643 2644 2645 2646

	/* 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;
}

2647
static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2648
{
2649
	const char *modmagic = get_modinfo(info, "vermagic");
2650 2651
	int err;

2652 2653 2654
	if (flags & MODULE_INIT_IGNORE_VERMAGIC)
		modmagic = NULL;

2655 2656 2657 2658 2659
	/* This is allowed: modprobe --force will invalidate it. */
	if (!modmagic) {
		err = try_to_force_load(mod, "bad vermagic");
		if (err)
			return err;
2660
	} else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2661
		pr_err("%s: version magic '%s' should be '%s'\n",
2662 2663 2664 2665
		       mod->name, modmagic, vermagic);
		return -ENOEXEC;
	}

2666
	if (!get_modinfo(info, "intree"))
2667
		add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2668

2669
	if (get_modinfo(info, "staging")) {
2670
		add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2671 2672
		pr_warn("%s: module is from the staging directory, the quality "
			"is unknown, you have been warned.\n", mod->name);
2673
	}
2674 2675

	/* Set up license info based on the info section */
2676
	set_license(mod, get_modinfo(info, "license"));
2677

2678 2679 2680
	return 0;
}

2681
static int find_module_sections(struct module *mod, struct load_info *info)
2682
{
2683
	mod->kp = section_objs(info, "__param",
2684
			       sizeof(*mod->kp), &mod->num_kp);
2685
	mod->syms = section_objs(info, "__ksymtab",
2686
				 sizeof(*mod->syms), &mod->num_syms);
2687 2688
	mod->crcs = section_addr(info, "__kcrctab");
	mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2689 2690
				     sizeof(*mod->gpl_syms),
				     &mod->num_gpl_syms);
2691 2692
	mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
	mod->gpl_future_syms = section_objs(info,
2693 2694 2695
					    "__ksymtab_gpl_future",
					    sizeof(*mod->gpl_future_syms),
					    &mod->num_gpl_future_syms);
2696
	mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2697 2698

#ifdef CONFIG_UNUSED_SYMBOLS
2699
	mod->unused_syms = section_objs(info, "__ksymtab_unused",
2700 2701
					sizeof(*mod->unused_syms),
					&mod->num_unused_syms);
2702 2703
	mod->unused_crcs = section_addr(info, "__kcrctab_unused");
	mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2704 2705
					    sizeof(*mod->unused_gpl_syms),
					    &mod->num_unused_gpl_syms);
2706
	mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2707 2708
#endif
#ifdef CONFIG_CONSTRUCTORS
2709
	mod->ctors = section_objs(info, ".ctors",
2710
				  sizeof(*mod->ctors), &mod->num_ctors);
2711 2712 2713 2714 2715 2716 2717 2718
	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.
		 */
2719
		pr_warn("%s: has both .ctors and .init_array.\n",
2720 2721 2722
		       mod->name);
		return -EINVAL;
	}
2723 2724 2725
#endif

#ifdef CONFIG_TRACEPOINTS
2726 2727 2728
	mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
					     sizeof(*mod->tracepoints_ptrs),
					     &mod->num_tracepoints);
2729
#endif
2730 2731 2732 2733 2734
#ifdef HAVE_JUMP_LABEL
	mod->jump_entries = section_objs(info, "__jump_table",
					sizeof(*mod->jump_entries),
					&mod->num_jump_entries);
#endif
2735
#ifdef CONFIG_EVENT_TRACING
2736
	mod->trace_events = section_objs(info, "_ftrace_events",
2737 2738 2739
					 sizeof(*mod->trace_events),
					 &mod->num_trace_events);
#endif
2740 2741 2742 2743 2744
#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
2745 2746
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
	/* sechdrs[0].sh_size is always zero */
2747
	mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2748 2749 2750
					     sizeof(*mod->ftrace_callsites),
					     &mod->num_ftrace_callsites);
#endif
2751

2752 2753 2754
	mod->extable = section_objs(info, "__ex_table",
				    sizeof(*mod->extable), &mod->num_exentries);

2755
	if (section_addr(info, "__obsparm"))
2756
		pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2757 2758 2759

	info->debug = section_objs(info, "__verbose",
				   sizeof(*info->debug), &info->num_debug);
2760 2761

	return 0;
2762 2763
}

2764
static int move_module(struct module *mod, struct load_info *info)
2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777
{
	int i;
	void *ptr;

	/* Do the allocs. */
	ptr = module_alloc_update_bounds(mod->core_size);
	/*
	 * 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)
2778
		return -ENOMEM;
2779 2780 2781 2782

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

2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799
	if (mod->init_size) {
		ptr = module_alloc_update_bounds(mod->init_size);
		/*
		 * 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) {
			module_free(mod, mod->module_core);
			return -ENOMEM;
		}
		memset(ptr, 0, mod->init_size);
		mod->module_init = ptr;
	} else
		mod->module_init = NULL;
2800 2801

	/* Transfer each section which specifies SHF_ALLOC */
2802
	pr_debug("final section addresses:\n");
2803
	for (i = 0; i < info->hdr->e_shnum; i++) {
2804
		void *dest;
2805
		Elf_Shdr *shdr = &info->sechdrs[i];
2806

2807
		if (!(shdr->sh_flags & SHF_ALLOC))
2808 2809
			continue;

2810
		if (shdr->sh_entsize & INIT_OFFSET_MASK)
2811
			dest = mod->module_init
2812
				+ (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2813
		else
2814
			dest = mod->module_core + shdr->sh_entsize;
2815

2816 2817
		if (shdr->sh_type != SHT_NOBITS)
			memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2818
		/* Update sh_addr to point to copy in image. */
2819
		shdr->sh_addr = (unsigned long)dest;
2820 2821
		pr_debug("\t0x%lx %s\n",
			 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2822
	}
2823 2824

	return 0;
2825 2826
}

2827
static int check_module_license_and_versions(struct module *mod)
2828 2829 2830 2831 2832 2833 2834
{
	/*
	 * 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)
2835
		add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2836 2837 2838

	/* driverloader was caught wrongly pretending to be under GPL */
	if (strcmp(mod->name, "driverloader") == 0)
2839 2840
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
2841

2842 2843
	/* lve claims to be GPL but upstream won't provide source */
	if (strcmp(mod->name, "lve") == 0)
2844 2845
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
2846

2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885
#ifdef CONFIG_MODVERSIONS
	if ((mod->num_syms && !mod->crcs)
	    || (mod->num_gpl_syms && !mod->gpl_crcs)
	    || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
#ifdef CONFIG_UNUSED_SYMBOLS
	    || (mod->num_unused_syms && !mod->unused_crcs)
	    || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
#endif
		) {
		return try_to_force_load(mod,
					 "no versions for exported symbols");
	}
#endif
	return 0;
}

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

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

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

	set_fs(old_fs);
}

2886 2887 2888 2889 2890 2891 2892 2893
int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
				     Elf_Shdr *sechdrs,
				     char *secstrings,
				     struct module *mod)
{
	return 0;
}

2894
static struct module *layout_and_allocate(struct load_info *info, int flags)
L
Linus Torvalds 已提交
2895
{
2896
	/* Module within temporary copy. */
L
Linus Torvalds 已提交
2897
	struct module *mod;
2898
	int err;
2899

2900
	mod = setup_load_info(info, flags);
2901 2902
	if (IS_ERR(mod))
		return mod;
L
Linus Torvalds 已提交
2903

2904
	err = check_modinfo(mod, info, flags);
2905 2906
	if (err)
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2907 2908

	/* Allow arches to frob section contents and sizes.  */
2909 2910
	err = module_frob_arch_sections(info->hdr, info->sechdrs,
					info->secstrings, mod);
L
Linus Torvalds 已提交
2911
	if (err < 0)
2912
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2913

2914 2915
	/* We will do a special allocation for per-cpu sections later. */
	info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
L
Linus Torvalds 已提交
2916 2917 2918 2919

	/* 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. */
2920 2921
	layout_sections(mod, info);
	layout_symtab(mod, info);
L
Linus Torvalds 已提交
2922

2923
	/* Allocate and move to the final place */
2924
	err = move_module(mod, info);
2925
	if (err)
2926
		return ERR_PTR(err);
2927 2928 2929

	/* Module has been copied to its final place now: return it. */
	mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2930
	kmemleak_load_module(mod, info);
2931 2932 2933 2934 2935 2936 2937
	return mod;
}

/* mod is no longer valid after this! */
static void module_deallocate(struct module *mod, struct load_info *info)
{
	percpu_modfree(mod);
2938
	module_arch_freeing_init(mod);
2939 2940 2941 2942
	module_free(mod, mod->module_init);
	module_free(mod, mod->module_core);
}

2943 2944 2945 2946 2947 2948 2949
int __weak module_finalize(const Elf_Ehdr *hdr,
			   const Elf_Shdr *sechdrs,
			   struct module *me)
{
	return 0;
}

2950 2951
static int post_relocation(struct module *mod, const struct load_info *info)
{
2952
	/* Sort exception table now relocations are done. */
2953 2954 2955 2956 2957 2958
	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);

2959
	/* Setup kallsyms-specific fields. */
2960 2961 2962 2963 2964 2965
	add_kallsyms(mod, info);

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

2966 2967 2968 2969 2970 2971 2972
/* Is this module of this name done loading?  No locks held. */
static bool finished_loading(const char *name)
{
	struct module *mod;
	bool ret;

	mutex_lock(&module_mutex);
2973
	mod = find_module_all(name, strlen(name), true);
2974 2975
	ret = !mod || mod->state == MODULE_STATE_LIVE
		|| mod->state == MODULE_STATE_GOING;
2976 2977 2978 2979 2980
	mutex_unlock(&module_mutex);

	return ret;
}

2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996
/* 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
}

/* This is where the real work happens */
static int do_init_module(struct module *mod)
{
	int ret = 0;

2997 2998 2999 3000 3001 3002
	/*
	 * 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;

3003 3004 3005 3006 3007
	do_mod_ctors(mod);
	/* Start the module */
	if (mod->init != NULL)
		ret = do_one_initcall(mod->init);
	if (ret < 0) {
3008 3009 3010 3011
		/*
		 * Init routine failed: abort.  Try to protect us from
		 * buggy refcounters.
		 */
3012 3013 3014 3015 3016 3017 3018 3019 3020 3021
		mod->state = MODULE_STATE_GOING;
		synchronize_sched();
		module_put(mod);
		blocking_notifier_call_chain(&module_notify_list,
					     MODULE_STATE_GOING, mod);
		free_module(mod);
		wake_up_all(&module_wq);
		return ret;
	}
	if (ret > 0) {
3022 3023 3024 3025
		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__);
3026 3027 3028 3029 3030 3031 3032 3033
		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);

3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052
	/*
	 * 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
	 */
	if (current->flags & PF_USED_ASYNC)
		async_synchronize_full();
3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063

	mutex_lock(&module_mutex);
	/* Drop initial reference. */
	module_put(mod);
	trim_init_extable(mod);
#ifdef CONFIG_KALLSYMS
	mod->num_symtab = mod->core_num_syms;
	mod->symtab = mod->core_symtab;
	mod->strtab = mod->core_strtab;
#endif
	unset_module_init_ro_nx(mod);
3064
	module_arch_freeing_init(mod);
3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083
	module_free(mod, mod->module_init);
	mod->module_init = NULL;
	mod->init_size = 0;
	mod->init_ro_size = 0;
	mod->init_text_size = 0;
	mutex_unlock(&module_mutex);
	wake_up_all(&module_wq);

	return 0;
}

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

	return 0;
}

3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109
/*
 * Can't use wait_event_interruptible() because our condition
 * 'finished_loading()' contains a blocking primitive itself (mutex_lock).
 */
static int wait_finished_loading(struct module *mod)
{
	DEFINE_WAIT_FUNC(wait, woken_wake_function);
	int ret = 0;

	add_wait_queue(&module_wq, &wait);
	for (;;) {
		if (finished_loading(mod->name))
			break;

		if (signal_pending(current)) {
			ret = -ERESTARTSYS;
			break;
		}

		wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
	}
	remove_wait_queue(&module_wq, &wait);

	return ret;
}

3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123
/*
 * 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);
3124 3125
	old = find_module_all(mod->name, strlen(mod->name), true);
	if (old != NULL) {
3126 3127 3128 3129
		if (old->state == MODULE_STATE_COMING
		    || old->state == MODULE_STATE_UNFORMED) {
			/* Wait in case it fails to load. */
			mutex_unlock(&module_mutex);
3130 3131

			err = wait_finished_loading(mod);
3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161
			if (err)
				goto out_unlocked;
			goto again;
		}
		err = -EEXIST;
		goto out;
	}
	list_add_rcu(&mod->list, &modules);
	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);

3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173
	/* Set RO and NX regions for core */
	set_section_ro_nx(mod->module_core,
				mod->core_text_size,
				mod->core_ro_size,
				mod->core_size);

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

3174 3175 3176
	/* Mark state as coming so strong_try_module_get() ignores us,
	 * but kallsyms etc. can see us. */
	mod->state = MODULE_STATE_COMING;
3177 3178 3179 3180 3181
	mutex_unlock(&module_mutex);

	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_COMING, mod);
	return 0;
3182 3183 3184 3185 3186 3187

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

3188 3189
static int unknown_module_param_cb(char *param, char *val, const char *modname)
{
3190
	/* Check for magic 'dyndbg' arg */
3191
	int ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3192 3193
	if (ret != 0)
		pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3194 3195 3196
	return 0;
}

3197 3198
/* Allocate and load the module: note that size of section 0 is always
   zero, and we rely on this for optional sections. */
3199 3200
static int load_module(struct load_info *info, const char __user *uargs,
		       int flags)
3201
{
3202
	struct module *mod;
3203
	long err;
3204
	char *after_dashes;
3205

3206 3207 3208
	err = module_sig_check(info);
	if (err)
		goto free_copy;
3209

3210
	err = elf_header_check(info);
3211
	if (err)
3212
		goto free_copy;
3213 3214

	/* Figure out module layout, and allocate all the memory. */
3215
	mod = layout_and_allocate(info, flags);
3216 3217
	if (IS_ERR(mod)) {
		err = PTR_ERR(mod);
3218
		goto free_copy;
L
Linus Torvalds 已提交
3219 3220
	}

3221 3222 3223
	/* Reserve our place in the list. */
	err = add_unformed_module(mod);
	if (err)
3224 3225
		goto free_module;

3226
#ifdef CONFIG_MODULE_SIG
3227
	mod->sig_ok = info->sig_ok;
3228
	if (!mod->sig_ok) {
3229 3230 3231
		pr_notice_once("%s: module verification failed: signature "
			       "and/or  required key missing - tainting "
			       "kernel\n", mod->name);
3232
		add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3233
	}
3234 3235
#endif

3236
	/* To avoid stressing percpu allocator, do this once we're unique. */
3237
	err = percpu_modalloc(mod, info);
3238 3239 3240
	if (err)
		goto unlink_mod;

3241
	/* Now module is in final location, initialize linked lists, etc. */
3242 3243
	err = module_unload_init(mod);
	if (err)
3244
		goto unlink_mod;
L
Linus Torvalds 已提交
3245

3246 3247
	/* Now we've got everything in the final locations, we can
	 * find optional sections. */
3248 3249 3250
	err = find_module_sections(mod, info);
	if (err)
		goto free_unload;
3251

3252
	err = check_module_license_and_versions(mod);
3253 3254
	if (err)
		goto free_unload;
3255

3256
	/* Set up MODINFO_ATTR fields */
3257
	setup_modinfo(mod, info);
3258

L
Linus Torvalds 已提交
3259
	/* Fix up syms, so that st_value is a pointer to location. */
3260
	err = simplify_symbols(mod, info);
L
Linus Torvalds 已提交
3261
	if (err < 0)
3262
		goto free_modinfo;
L
Linus Torvalds 已提交
3263

3264
	err = apply_relocations(mod, info);
3265
	if (err < 0)
3266
		goto free_modinfo;
L
Linus Torvalds 已提交
3267

3268
	err = post_relocation(mod, info);
L
Linus Torvalds 已提交
3269
	if (err < 0)
3270
		goto free_modinfo;
L
Linus Torvalds 已提交
3271

3272
	flush_module_icache(mod);
3273

3274 3275 3276 3277 3278 3279
	/* 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;
	}
3280

3281
	dynamic_debug_setup(info->debug, info->num_debug);
3282

3283 3284 3285
	/* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
	ftrace_module_init(mod);

3286 3287 3288
	/* Finally it's fully formed, ready to start executing. */
	err = complete_formation(mod, info);
	if (err)
3289
		goto ddebug_cleanup;
3290

3291
	/* Module is ready to execute: parsing args may do that. */
3292 3293 3294 3295
	after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
				  -32768, 32767, unknown_module_param_cb);
	if (IS_ERR(after_dashes)) {
		err = PTR_ERR(after_dashes);
3296
		goto bug_cleanup;
3297 3298 3299 3300
	} else if (after_dashes) {
		pr_warn("%s: parameters '%s' after `--' ignored\n",
		       mod->name, after_dashes);
	}
L
Linus Torvalds 已提交
3301

3302
	/* Link in to syfs. */
3303
	err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
L
Linus Torvalds 已提交
3304
	if (err < 0)
3305
		goto bug_cleanup;
3306

3307
	/* Get rid of temporary copy. */
3308
	free_copy(info);
L
Linus Torvalds 已提交
3309 3310

	/* Done! */
3311
	trace_module_load(mod);
3312 3313

	return do_init_module(mod);
L
Linus Torvalds 已提交
3314

3315 3316
 bug_cleanup:
	/* module_bug_cleanup needs module_mutex protection */
3317
	mutex_lock(&module_mutex);
3318
	module_bug_cleanup(mod);
3319
	mutex_unlock(&module_mutex);
3320 3321 3322 3323 3324

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

3325
 ddebug_cleanup:
3326
	dynamic_debug_remove(info->debug);
3327
	synchronize_sched();
3328 3329
	kfree(mod->args);
 free_arch_cleanup:
L
Linus Torvalds 已提交
3330
	module_arch_cleanup(mod);
3331
 free_modinfo:
3332
	free_modinfo(mod);
3333
 free_unload:
L
Linus Torvalds 已提交
3334
	module_unload_free(mod);
3335 3336 3337 3338 3339
 unlink_mod:
	mutex_lock(&module_mutex);
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
	wake_up_all(&module_wq);
3340 3341
	/* Wait for RCU synchronizing before releasing mod->list. */
	synchronize_rcu();
3342
	mutex_unlock(&module_mutex);
3343
 free_module:
3344
	module_deallocate(mod, info);
3345
 free_copy:
3346 3347
	free_copy(info);
	return err;
3348 3349
}

3350 3351
SYSCALL_DEFINE3(init_module, void __user *, umod,
		unsigned long, len, const char __user *, uargs)
L
Linus Torvalds 已提交
3352
{
3353 3354
	int err;
	struct load_info info = { };
L
Linus Torvalds 已提交
3355

3356 3357 3358
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3359

3360 3361
	pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
	       umod, len, uargs);
L
Linus Torvalds 已提交
3362

3363 3364 3365
	err = copy_module_from_user(umod, len, &info);
	if (err)
		return err;
L
Linus Torvalds 已提交
3366

3367
	return load_module(&info, uargs, 0);
3368
}
3369

3370
SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3371 3372 3373
{
	int err;
	struct load_info info = { };
3374

3375 3376 3377
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3378

3379
	pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3380

3381 3382 3383
	if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
		      |MODULE_INIT_IGNORE_VERMAGIC))
		return -EINVAL;
3384

3385 3386 3387
	err = copy_module_from_fd(fd, &info);
	if (err)
		return err;
L
Linus Torvalds 已提交
3388

3389
	return load_module(&info, uargs, flags);
L
Linus Torvalds 已提交
3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403
}

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 $d.
 */
static inline int is_arm_mapping_symbol(const char *str)
{
3404 3405
	if (str[0] == '.' && str[1] == 'L')
		return true;
3406
	return str[0] == '$' && strchr("axtd", str[1])
L
Linus Torvalds 已提交
3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418
	       && (str[2] == '\0' || str[2] == '.');
}

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

	/* At worse, next value is at end of module */
3419
	if (within_module_init(addr, mod))
L
Linus Torvalds 已提交
3420
		nextval = (unsigned long)mod->module_init+mod->init_text_size;
3421
	else
L
Linus Torvalds 已提交
3422 3423
		nextval = (unsigned long)mod->module_core+mod->core_text_size;

L
Lucas De Marchi 已提交
3424
	/* Scan for closest preceding symbol, and next symbol. (ELF
3425
	   starts real symbols at 1). */
L
Linus Torvalds 已提交
3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446
	for (i = 1; i < mod->num_symtab; i++) {
		if (mod->symtab[i].st_shndx == SHN_UNDEF)
			continue;

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

	if (!best)
		return NULL;

3447 3448 3449 3450
	if (size)
		*size = nextval - mod->symtab[best].st_value;
	if (offset)
		*offset = addr - mod->symtab[best].st_value;
L
Linus Torvalds 已提交
3451 3452 3453
	return mod->strtab + mod->symtab[best].st_name;
}

3454 3455
/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3456
const char *module_address_lookup(unsigned long addr,
3457 3458 3459 3460
			    unsigned long *size,
			    unsigned long *offset,
			    char **modname,
			    char *namebuf)
L
Linus Torvalds 已提交
3461 3462
{
	struct module *mod;
3463
	const char *ret = NULL;
L
Linus Torvalds 已提交
3464

3465
	preempt_disable();
3466
	list_for_each_entry_rcu(mod, &modules, list) {
3467 3468
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3469
		if (within_module(addr, mod)) {
3470 3471
			if (modname)
				*modname = mod->name;
3472 3473
			ret = get_ksymbol(mod, addr, size, offset);
			break;
L
Linus Torvalds 已提交
3474 3475
		}
	}
3476 3477 3478 3479 3480
	/* Make a copy in here where it's safe */
	if (ret) {
		strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
		ret = namebuf;
	}
3481
	preempt_enable();
3482
	return ret;
L
Linus Torvalds 已提交
3483 3484
}

3485 3486 3487 3488
int lookup_module_symbol_name(unsigned long addr, char *symname)
{
	struct module *mod;

3489
	preempt_disable();
3490
	list_for_each_entry_rcu(mod, &modules, list) {
3491 3492
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3493
		if (within_module(addr, mod)) {
3494 3495 3496 3497 3498
			const char *sym;

			sym = get_ksymbol(mod, addr, NULL, NULL);
			if (!sym)
				goto out;
3499
			strlcpy(symname, sym, KSYM_NAME_LEN);
3500
			preempt_enable();
3501 3502 3503 3504
			return 0;
		}
	}
out:
3505
	preempt_enable();
3506 3507 3508
	return -ERANGE;
}

3509 3510 3511 3512 3513
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
			unsigned long *offset, char *modname, char *name)
{
	struct module *mod;

3514
	preempt_disable();
3515
	list_for_each_entry_rcu(mod, &modules, list) {
3516 3517
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3518
		if (within_module(addr, mod)) {
3519 3520 3521 3522 3523 3524
			const char *sym;

			sym = get_ksymbol(mod, addr, size, offset);
			if (!sym)
				goto out;
			if (modname)
3525
				strlcpy(modname, mod->name, MODULE_NAME_LEN);
3526
			if (name)
3527
				strlcpy(name, sym, KSYM_NAME_LEN);
3528
			preempt_enable();
3529 3530 3531 3532
			return 0;
		}
	}
out:
3533
	preempt_enable();
3534 3535 3536
	return -ERANGE;
}

3537 3538
int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
			char *name, char *module_name, int *exported)
L
Linus Torvalds 已提交
3539 3540 3541
{
	struct module *mod;

3542
	preempt_disable();
3543
	list_for_each_entry_rcu(mod, &modules, list) {
3544 3545
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
L
Linus Torvalds 已提交
3546 3547 3548
		if (symnum < mod->num_symtab) {
			*value = mod->symtab[symnum].st_value;
			*type = mod->symtab[symnum].st_info;
3549
			strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3550 3551
				KSYM_NAME_LEN);
			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3552
			*exported = is_exported(name, *value, mod);
3553
			preempt_enable();
3554
			return 0;
L
Linus Torvalds 已提交
3555 3556 3557
		}
		symnum -= mod->num_symtab;
	}
3558
	preempt_enable();
3559
	return -ERANGE;
L
Linus Torvalds 已提交
3560 3561 3562 3563 3564 3565 3566
}

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

	for (i = 0; i < mod->num_symtab; i++)
3567 3568
		if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
		    mod->symtab[i].st_info != 'U')
L
Linus Torvalds 已提交
3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580
			return mod->symtab[i].st_value;
	return 0;
}

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

	/* Don't lock: we're in enough trouble already. */
3581
	preempt_disable();
L
Linus Torvalds 已提交
3582
	if ((colon = strchr(name, ':')) != NULL) {
3583
		if ((mod = find_module_all(name, colon - name, false)) != NULL)
L
Linus Torvalds 已提交
3584 3585
			ret = mod_find_symname(mod, colon+1);
	} else {
3586 3587 3588
		list_for_each_entry_rcu(mod, &modules, list) {
			if (mod->state == MODULE_STATE_UNFORMED)
				continue;
L
Linus Torvalds 已提交
3589 3590
			if ((ret = mod_find_symname(mod, name)) != 0)
				break;
3591
		}
L
Linus Torvalds 已提交
3592
	}
3593
	preempt_enable();
L
Linus Torvalds 已提交
3594 3595
	return ret;
}
3596 3597 3598 3599 3600 3601 3602 3603 3604 3605

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;

	list_for_each_entry(mod, &modules, list) {
3606 3607
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3608 3609 3610 3611 3612 3613 3614 3615 3616
		for (i = 0; i < mod->num_symtab; i++) {
			ret = fn(data, mod->strtab + mod->symtab[i].st_name,
				 mod, mod->symtab[i].st_value);
			if (ret != 0)
				return ret;
		}
	}
	return 0;
}
L
Linus Torvalds 已提交
3617 3618
#endif /* CONFIG_KALLSYMS */

3619
static char *module_flags(struct module *mod, char *buf)
3620 3621 3622
{
	int bx = 0;

3623
	BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3624 3625 3626
	if (mod->taints ||
	    mod->state == MODULE_STATE_GOING ||
	    mod->state == MODULE_STATE_COMING) {
3627
		buf[bx++] = '(';
3628
		bx += module_flags_taint(mod, buf + bx);
3629 3630 3631 3632 3633 3634
		/* 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++] = '+';
3635 3636 3637 3638 3639 3640 3641
		buf[bx++] = ')';
	}
	buf[bx] = '\0';

	return buf;
}

3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659
#ifdef CONFIG_PROC_FS
/* Called by the /proc file system to return a list of modules. */
static void *m_start(struct seq_file *m, loff_t *pos)
{
	mutex_lock(&module_mutex);
	return seq_list_start(&modules, *pos);
}

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

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

L
Linus Torvalds 已提交
3660 3661 3662
static int m_show(struct seq_file *m, void *p)
{
	struct module *mod = list_entry(p, struct module, list);
3663 3664
	char buf[8];

3665 3666 3667 3668
	/* We always ignore unformed modules. */
	if (mod->state == MODULE_STATE_UNFORMED)
		return 0;

3669
	seq_printf(m, "%s %u",
L
Linus Torvalds 已提交
3670 3671 3672 3673 3674
		   mod->name, mod->init_size + mod->core_size);
	print_unload_info(m, mod);

	/* Informative for users. */
	seq_printf(m, " %s",
3675 3676
		   mod->state == MODULE_STATE_GOING ? "Unloading" :
		   mod->state == MODULE_STATE_COMING ? "Loading" :
L
Linus Torvalds 已提交
3677 3678
		   "Live");
	/* Used by oprofile and other similar tools. */
3679
	seq_printf(m, " 0x%pK", mod->module_core);
L
Linus Torvalds 已提交
3680

3681 3682
	/* Taints info */
	if (mod->taints)
3683
		seq_printf(m, " %s", module_flags(mod, buf));
3684

3685
	seq_puts(m, "\n");
L
Linus Torvalds 已提交
3686 3687 3688 3689 3690 3691 3692 3693
	return 0;
}

/* Format: modulename size refcount deps address

   Where refcount is a number or -, and deps is a comma-separated list
   of depends or -.
*/
3694
static const struct seq_operations modules_op = {
L
Linus Torvalds 已提交
3695 3696 3697 3698 3699 3700
	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= m_show
};

3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720
static int modules_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &modules_op);
}

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

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

L
Linus Torvalds 已提交
3721 3722 3723 3724 3725 3726
/* 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;

3727
	preempt_disable();
3728
	list_for_each_entry_rcu(mod, &modules, list) {
3729 3730
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
L
Linus Torvalds 已提交
3731 3732
		if (mod->num_exentries == 0)
			continue;
3733

L
Linus Torvalds 已提交
3734 3735 3736 3737 3738 3739
		e = search_extable(mod->extable,
				   mod->extable + mod->num_exentries - 1,
				   addr);
		if (e)
			break;
	}
3740
	preempt_enable();
L
Linus Torvalds 已提交
3741 3742

	/* Now, if we found one, we are running inside it now, hence
3743
	   we cannot unload the module, hence no refcnt needed. */
L
Linus Torvalds 已提交
3744 3745 3746
	return e;
}

3747
/*
R
Rusty Russell 已提交
3748 3749 3750 3751 3752
 * 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).
3753
 */
R
Rusty Russell 已提交
3754
bool is_module_address(unsigned long addr)
3755
{
R
Rusty Russell 已提交
3756
	bool ret;
3757

3758
	preempt_disable();
R
Rusty Russell 已提交
3759
	ret = __module_address(addr) != NULL;
3760
	preempt_enable();
3761

R
Rusty Russell 已提交
3762
	return ret;
3763 3764
}

R
Rusty Russell 已提交
3765 3766 3767 3768 3769 3770 3771
/*
 * __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.
 */
3772
struct module *__module_address(unsigned long addr)
L
Linus Torvalds 已提交
3773 3774 3775
{
	struct module *mod;

3776 3777 3778
	if (addr < module_addr_min || addr > module_addr_max)
		return NULL;

3779 3780 3781
	list_for_each_entry_rcu(mod, &modules, list) {
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3782
		if (within_module(addr, mod))
L
Linus Torvalds 已提交
3783
			return mod;
3784
	}
L
Linus Torvalds 已提交
3785 3786
	return NULL;
}
3787
EXPORT_SYMBOL_GPL(__module_address);
L
Linus Torvalds 已提交
3788

R
Rusty Russell 已提交
3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825
/*
 * is_module_text_address - is this address inside module code?
 * @addr: the address to check.
 *
 * See is_module_address() if you simply want to see if the address is
 * anywhere in a module.  See kernel_text_address() for testing if an
 * address corresponds to kernel or module code.
 */
bool is_module_text_address(unsigned long addr)
{
	bool ret;

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

	return ret;
}

/*
 * __module_text_address - get the module whose code contains an address.
 * @addr: the address.
 *
 * Must be called with preempt disabled or module mutex held so that
 * module doesn't get freed during this.
 */
struct module *__module_text_address(unsigned long addr)
{
	struct module *mod = __module_address(addr);
	if (mod) {
		/* Make sure it's within the text section. */
		if (!within(addr, mod->module_init, mod->init_text_size)
		    && !within(addr, mod->module_core, mod->core_text_size))
			mod = NULL;
	}
	return mod;
}
3826
EXPORT_SYMBOL_GPL(__module_text_address);
R
Rusty Russell 已提交
3827

L
Linus Torvalds 已提交
3828 3829 3830 3831
/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
	struct module *mod;
3832
	char buf[8];
L
Linus Torvalds 已提交
3833

3834
	printk(KERN_DEFAULT "Modules linked in:");
3835 3836
	/* Most callers should already have preempt disabled, but make sure */
	preempt_disable();
3837 3838 3839
	list_for_each_entry_rcu(mod, &modules, list) {
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
J
Jiri Slaby 已提交
3840
		pr_cont(" %s%s", mod->name, module_flags(mod, buf));
3841
	}
3842
	preempt_enable();
3843
	if (last_unloaded_module[0])
J
Jiri Slaby 已提交
3844 3845
		pr_cont(" [last unloaded: %s]", last_unloaded_module);
	pr_cont("\n");
L
Linus Torvalds 已提交
3846 3847 3848
}

#ifdef CONFIG_MODVERSIONS
3849 3850 3851 3852 3853 3854
/* 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,
3855
		   struct tracepoint * const *tp)
3856 3857 3858
{
}
EXPORT_SYMBOL(module_layout);
L
Linus Torvalds 已提交
3859
#endif
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