module.c 97.7 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)
L
Linus Torvalds 已提交
583 584 585 586
{
	/* pcpusec should be 0, and size of that section should be 0. */
	BUG_ON(size != 0);
}
587 588 589 590
bool is_module_percpu_address(unsigned long addr)
{
	return false;
}
591

L
Linus Torvalds 已提交
592 593
#endif /* CONFIG_SMP */

594 595 596 597 598 599
#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,   \
600
			struct module_kobject *mk, char *buffer)      \
601
{                                                                     \
602
	return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field);  \
603 604 605 606 607 608 609
}                                                                     \
static int modinfo_##field##_exists(struct module *mod)               \
{                                                                     \
	return mod->field != NULL;                                    \
}                                                                     \
static void free_modinfo_##field(struct module *mod)                  \
{                                                                     \
D
Daniel Walker 已提交
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

L
Linus Torvalds 已提交
633
/* Init the unload section of the module. */
634
static int module_unload_init(struct module *mod)
L
Linus Torvalds 已提交
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
Linus Torvalds 已提交
645
	/* Hold reference count during initialization. */
646
	atomic_inc(&mod->refcnt);
647 648

	return 0;
L
Linus Torvalds 已提交
649 650 651 652 653 654 655
}

/* 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);
L
Linus Torvalds 已提交
659 660 661
			return 1;
		}
	}
662
	pr_debug("%s does not use %s!\n", a->name, b->name);
L
Linus Torvalds 已提交
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) {
A
Andrew Morton 已提交
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
Linus Torvalds 已提交
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;
L
Linus Torvalds 已提交
703

704 705
	err = add_module_usage(a, b);
	if (err) {
L
Linus Torvalds 已提交
706
		module_put(b);
707
		return err;
L
Linus Torvalds 已提交
708
	}
709
	return 0;
L
Linus Torvalds 已提交
710
}
711
EXPORT_SYMBOL_GPL(ref_module);
L
Linus Torvalds 已提交
712 713 714 715

/* Clear the unload stuff of the module. */
static void module_unload_free(struct module *mod)
{
716
	struct module_use *use, *tmp;
L
Linus Torvalds 已提交
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);
L
Linus Torvalds 已提交
726
	}
727
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
728 729 730
}

#ifdef CONFIG_MODULE_FORCE_UNLOAD
731
static inline int try_force_unload(unsigned int flags)
L
Linus Torvalds 已提交
732 733 734
{
	int ret = (flags & O_TRUNC);
	if (ret)
735
		add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
L
Linus Torvalds 已提交
736 737 738
	return ret;
}
#else
739
static inline int try_force_unload(unsigned int flags)
L
Linus Torvalds 已提交
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)
L
Linus Torvalds 已提交
747
{
748
	int ret;
L
Linus Torvalds 已提交
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);
L
Linus Torvalds 已提交
756

757 758
	return ret;
}
L
Linus Torvalds 已提交
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))
L
Linus Torvalds 已提交
766 767 768 769
			return -EWOULDBLOCK;
	}

	/* Mark it as dying. */
770
	mod->state = MODULE_STATE_GOING;
L
Linus Torvalds 已提交
771

772
	return 0;
L
Linus Torvalds 已提交
773 774
}

775 776 777 778 779 780 781 782 783 784
/**
 * module_refcount - return the refcount or -1 if unloading
 *
 * @mod:	the module we're checking
 *
 * Returns:
 *	-1 if the module is in the process of unloading
 *	otherwise the number of references in the kernel to the module
 */
int module_refcount(struct module *mod)
L
Linus Torvalds 已提交
785
{
786
	return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
L
Linus Torvalds 已提交
787 788 789 790 791 792
}
EXPORT_SYMBOL(module_refcount);

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

793 794
SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
		unsigned int, flags)
L
Linus Torvalds 已提交
795 796
{
	struct module *mod;
797
	char name[MODULE_NAME_LEN];
L
Linus Torvalds 已提交
798 799
	int ret, forced = 0;

800
	if (!capable(CAP_SYS_MODULE) || modules_disabled)
801 802 803 804 805 806
		return -EPERM;

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

807 808
	if (mutex_lock_interruptible(&module_mutex) != 0)
		return -EINTR;
L
Linus Torvalds 已提交
809 810 811 812 813 814 815

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

816
	if (!list_empty(&mod->source_list)) {
L
Linus Torvalds 已提交
817 818 819 820 821 822 823
		/* 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) {
824
		/* FIXME: if (force), slam module count damn the torpedoes */
825
		pr_debug("%s already dying\n", mod->name);
L
Linus Torvalds 已提交
826 827 828 829 830
		ret = -EBUSY;
		goto out;
	}

	/* If it has an init func, it must have an exit func to unload */
R
Rusty Russell 已提交
831
	if (mod->init && !mod->exit) {
832
		forced = try_force_unload(flags);
L
Linus Torvalds 已提交
833 834 835 836 837 838 839 840 841 842 843 844
		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;

845
	mutex_unlock(&module_mutex);
L
Lucas De Marchi 已提交
846
	/* Final destruction now no one is using it. */
847
	if (mod->exit != NULL)
L
Linus Torvalds 已提交
848
		mod->exit();
849 850
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
851
	async_synchronize_full();
852

853
	/* Store the name of the last unloaded module for diagnostic purposes */
854
	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
L
Linus Torvalds 已提交
855

856 857 858
	free_module(mod);
	return 0;
out:
859
	mutex_unlock(&module_mutex);
L
Linus Torvalds 已提交
860 861 862
	return ret;
}

863
static inline void print_unload_info(struct seq_file *m, struct module *mod)
L
Linus Torvalds 已提交
864 865 866 867
{
	struct module_use *use;
	int printed_something = 0;

868
	seq_printf(m, " %i ", module_refcount(mod));
L
Linus Torvalds 已提交
869

870 871 872 873
	/*
	 * Always include a trailing , so userspace can differentiate
	 * between this and the old multi-field proc format.
	 */
874
	list_for_each_entry(use, &mod->source_list, source_list) {
L
Linus Torvalds 已提交
875
		printed_something = 1;
876
		seq_printf(m, "%s,", use->source->name);
L
Linus Torvalds 已提交
877 878 879 880
	}

	if (mod->init != NULL && mod->exit == NULL) {
		printed_something = 1;
881
		seq_puts(m, "[permanent],");
L
Linus Torvalds 已提交
882 883 884
	}

	if (!printed_something)
885
		seq_puts(m, "-");
L
Linus Torvalds 已提交
886 887 888 889 890 891
}

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

R
Rusty Russell 已提交
892
	preempt_disable();
893
	if (!find_symbol(symbol, &owner, NULL, true, false))
L
Linus Torvalds 已提交
894 895
		BUG();
	module_put(owner);
R
Rusty Russell 已提交
896
	preempt_enable();
L
Linus Torvalds 已提交
897 898 899
}
EXPORT_SYMBOL(__symbol_put);

900
/* Note this assumes addr is a function, which it currently always is. */
L
Linus Torvalds 已提交
901 902
void symbol_put_addr(void *addr)
{
903
	struct module *modaddr;
904
	unsigned long a = (unsigned long)dereference_function_descriptor(addr);
L
Linus Torvalds 已提交
905

906
	if (core_kernel_text(a))
907
		return;
L
Linus Torvalds 已提交
908

909 910
	/* module_text_address is safe here: we're supposed to have reference
	 * to module from symbol_get, so it can't go away. */
911
	modaddr = __module_text_address(a);
912
	BUG_ON(!modaddr);
913
	module_put(modaddr);
L
Linus Torvalds 已提交
914 915 916 917
}
EXPORT_SYMBOL_GPL(symbol_put_addr);

static ssize_t show_refcnt(struct module_attribute *mattr,
918
			   struct module_kobject *mk, char *buffer)
L
Linus Torvalds 已提交
919
{
920
	return sprintf(buffer, "%i\n", module_refcount(mk->mod));
L
Linus Torvalds 已提交
921 922
}

923 924
static struct module_attribute modinfo_refcnt =
	__ATTR(refcnt, 0444, show_refcnt, NULL);
L
Linus Torvalds 已提交
925

926 927 928 929
void __module_get(struct module *module)
{
	if (module) {
		preempt_disable();
930
		atomic_inc(&module->refcnt);
931 932 933 934 935 936 937 938 939 940 941 942
		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();
943 944 945
		/* Note: here, we can fail to get a reference */
		if (likely(module_is_live(module) &&
			   atomic_inc_not_zero(&module->refcnt) != 0))
946
			trace_module_get(module, _RET_IP_);
947
		else
948 949 950 951 952 953 954 955
			ret = false;

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

A
Al Viro 已提交
956 957
void module_put(struct module *module)
{
958 959
	int ret;

A
Al Viro 已提交
960
	if (module) {
961
		preempt_disable();
962 963
		ret = atomic_dec_if_positive(&module->refcnt);
		WARN_ON(ret < 0);	/* Failed to put refcount */
964
		trace_module_put(module, _RET_IP_);
965
		preempt_enable();
A
Al Viro 已提交
966 967 968 969
	}
}
EXPORT_SYMBOL(module_put);

L
Linus Torvalds 已提交
970
#else /* !CONFIG_MODULE_UNLOAD */
971
static inline void print_unload_info(struct seq_file *m, struct module *mod)
L
Linus Torvalds 已提交
972 973
{
	/* We don't know the usage count, or what modules are using. */
974
	seq_puts(m, " - -");
L
Linus Torvalds 已提交
975 976 977 978 979 980
}

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

981
int ref_module(struct module *a, struct module *b)
L
Linus Torvalds 已提交
982
{
983
	return strong_try_module_get(b);
L
Linus Torvalds 已提交
984
}
985
EXPORT_SYMBOL_GPL(ref_module);
L
Linus Torvalds 已提交
986

987
static inline int module_unload_init(struct module *mod)
L
Linus Torvalds 已提交
988
{
989
	return 0;
L
Linus Torvalds 已提交
990 991 992
}
#endif /* CONFIG_MODULE_UNLOAD */

993 994 995 996 997 998 999 1000 1001 1002 1003 1004
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';
1005
	if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1006
		buf[l++] = 'E';
1007 1008
	/*
	 * TAINT_FORCED_RMMOD: could be added.
1009
	 * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1010 1011 1012 1013 1014
	 * apply to modules.
	 */
	return l;
}

1015
static ssize_t show_initstate(struct module_attribute *mattr,
1016
			      struct module_kobject *mk, char *buffer)
1017 1018 1019
{
	const char *state = "unknown";

1020
	switch (mk->mod->state) {
1021 1022 1023 1024 1025 1026 1027 1028 1029
	case MODULE_STATE_LIVE:
		state = "live";
		break;
	case MODULE_STATE_COMING:
		state = "coming";
		break;
	case MODULE_STATE_GOING:
		state = "going";
		break;
1030 1031
	default:
		BUG();
1032 1033 1034 1035
	}
	return sprintf(buffer, "%s\n", state);
}

1036 1037
static struct module_attribute modinfo_initstate =
	__ATTR(initstate, 0444, show_initstate, NULL);
1038

1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049
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;
}

1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082
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);
1083

1084
static struct module_attribute *modinfo_attrs[] = {
1085
	&module_uevent,
1086 1087
	&modinfo_version,
	&modinfo_srcversion,
1088 1089 1090 1091
	&modinfo_initstate,
	&modinfo_coresize,
	&modinfo_initsize,
	&modinfo_taint,
1092
#ifdef CONFIG_MODULE_UNLOAD
1093
	&modinfo_refcnt,
1094 1095 1096 1097
#endif
	NULL,
};

L
Linus Torvalds 已提交
1098 1099
static const char vermagic[] = VERMAGIC_STRING;

1100
static int try_to_force_load(struct module *mod, const char *reason)
1101 1102
{
#ifdef CONFIG_MODULE_FORCE_LOAD
A
Andi Kleen 已提交
1103
	if (!test_taint(TAINT_FORCED_MODULE))
A
Andrew Morton 已提交
1104
		pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1105
	add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1106 1107 1108 1109 1110 1111
	return 0;
#else
	return -ENOEXEC;
#endif
}

L
Linus Torvalds 已提交
1112
#ifdef CONFIG_MODVERSIONS
1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123
/* 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
1124 1125 1126
static int check_version(Elf_Shdr *sechdrs,
			 unsigned int versindex,
			 const char *symname,
1127
			 struct module *mod,
1128 1129
			 const unsigned long *crc,
			 const struct module *crc_owner)
L
Linus Torvalds 已提交
1130 1131 1132 1133 1134 1135 1136 1137
{
	unsigned int i, num_versions;
	struct modversion_info *versions;

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

1138 1139 1140 1141
	/* 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
1142 1143 1144 1145 1146 1147 1148 1149
	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;

1150
		if (versions[i].crc == maybe_relocated(*crc, crc_owner))
L
Linus Torvalds 已提交
1151
			return 1;
1152
		pr_debug("Found checksum %lX vs module %lX\n",
1153
		       maybe_relocated(*crc, crc_owner), versions[i].crc);
1154
		goto bad_version;
L
Linus Torvalds 已提交
1155
	}
1156

A
Andrew Morton 已提交
1157
	pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1158
	return 0;
1159 1160

bad_version:
1161
	pr_warn("%s: disagrees about version of symbol %s\n",
1162 1163
	       mod->name, symname);
	return 0;
L
Linus Torvalds 已提交
1164 1165 1166 1167 1168 1169 1170 1171
}

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

1172 1173
	/* Since this should be found in kernel (which can't be removed),
	 * no locking is necessary. */
R
Rusty Russell 已提交
1174
	if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1175
			 &crc, true, false))
L
Linus Torvalds 已提交
1176
		BUG();
1177 1178
	return check_version(sechdrs, versindex,
			     VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1179
			     NULL);
L
Linus Torvalds 已提交
1180 1181
}

1182 1183 1184
/* 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
1185
{
1186 1187 1188 1189
	if (has_crcs) {
		amagic += strcspn(amagic, " ");
		bmagic += strcspn(bmagic, " ");
	}
L
Linus Torvalds 已提交
1190 1191 1192 1193 1194 1195
	return strcmp(amagic, bmagic) == 0;
}
#else
static inline int check_version(Elf_Shdr *sechdrs,
				unsigned int versindex,
				const char *symname,
1196
				struct module *mod,
1197 1198
				const unsigned long *crc,
				const struct module *crc_owner)
L
Linus Torvalds 已提交
1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209
{
	return 1;
}

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

1210 1211
static inline int same_magic(const char *amagic, const char *bmagic,
			     bool has_crcs)
L
Linus Torvalds 已提交
1212 1213 1214 1215 1216
{
	return strcmp(amagic, bmagic) == 0;
}
#endif /* CONFIG_MODVERSIONS */

1217
/* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1218 1219
static const struct kernel_symbol *resolve_symbol(struct module *mod,
						  const struct load_info *info,
1220
						  const char *name,
1221
						  char ownername[])
L
Linus Torvalds 已提交
1222 1223
{
	struct module *owner;
1224
	const struct kernel_symbol *sym;
L
Linus Torvalds 已提交
1225
	const unsigned long *crc;
1226
	int err;
L
Linus Torvalds 已提交
1227

1228
	mutex_lock(&module_mutex);
1229
	sym = find_symbol(name, &owner, &crc,
A
Andi Kleen 已提交
1230
			  !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1231 1232 1233
	if (!sym)
		goto unlock;

1234 1235
	if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
			   owner)) {
1236 1237
		sym = ERR_PTR(-EINVAL);
		goto getname;
L
Linus Torvalds 已提交
1238
	}
1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249

	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:
1250
	mutex_unlock(&module_mutex);
1251
	return sym;
L
Linus Torvalds 已提交
1252 1253
}

1254 1255 1256 1257
static const struct kernel_symbol *
resolve_symbol_wait(struct module *mod,
		    const struct load_info *info,
		    const char *name)
1258 1259
{
	const struct kernel_symbol *ksym;
1260
	char owner[MODULE_NAME_LEN];
1261 1262

	if (wait_event_interruptible_timeout(module_wq,
1263 1264
			!IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
			|| PTR_ERR(ksym) != -EBUSY,
1265
					     30 * HZ) <= 0) {
A
Andrew Morton 已提交
1266 1267
		pr_warn("%s: gave up waiting for init of module %s.\n",
			mod->name, owner);
1268 1269 1270 1271
	}
	return ksym;
}

L
Linus Torvalds 已提交
1272 1273 1274 1275
/*
 * /sys/module/foo/sections stuff
 * J. Corbet <corbet@lwn.net>
 */
R
Rusty Russell 已提交
1276
#ifdef CONFIG_SYSFS
1277

R
Rusty Russell 已提交
1278
#ifdef CONFIG_KALLSYMS
1279 1280 1281 1282 1283
static inline bool sect_empty(const Elf_Shdr *sect)
{
	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
}

1284
struct module_sect_attr {
1285 1286 1287 1288 1289
	struct module_attribute mattr;
	char *name;
	unsigned long address;
};

1290
struct module_sect_attrs {
1291 1292 1293 1294 1295
	struct attribute_group grp;
	unsigned int nsections;
	struct module_sect_attr attrs[0];
};

L
Linus Torvalds 已提交
1296
static ssize_t module_sect_show(struct module_attribute *mattr,
1297
				struct module_kobject *mk, char *buf)
L
Linus Torvalds 已提交
1298 1299 1300
{
	struct module_sect_attr *sattr =
		container_of(mattr, struct module_sect_attr, mattr);
1301
	return sprintf(buf, "0x%pK\n", (void *)sattr->address);
L
Linus Torvalds 已提交
1302 1303
}

1304 1305
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
1306
	unsigned int section;
1307 1308 1309 1310 1311 1312

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

R
Rusty Russell 已提交
1313
static void add_sect_attrs(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
1314 1315 1316 1317 1318
{
	unsigned int nloaded = 0, i, size[2];
	struct module_sect_attrs *sect_attrs;
	struct module_sect_attr *sattr;
	struct attribute **gattr;
D
Daniel Walker 已提交
1319

L
Linus Torvalds 已提交
1320
	/* Count loaded sections and allocate structures */
R
Rusty Russell 已提交
1321 1322
	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]))
L
Linus Torvalds 已提交
1323 1324 1325 1326 1327
			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]);
1328 1329
	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
	if (sect_attrs == NULL)
L
Linus Torvalds 已提交
1330 1331 1332 1333 1334 1335
		return;

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

1336
	sect_attrs->nsections = 0;
L
Linus Torvalds 已提交
1337 1338
	sattr = &sect_attrs->attrs[0];
	gattr = &sect_attrs->grp.attrs[0];
R
Rusty Russell 已提交
1339 1340 1341
	for (i = 0; i < info->hdr->e_shnum; i++) {
		Elf_Shdr *sec = &info->sechdrs[i];
		if (sect_empty(sec))
1342
			continue;
R
Rusty Russell 已提交
1343 1344
		sattr->address = sec->sh_addr;
		sattr->name = kstrdup(info->secstrings + sec->sh_name,
1345 1346 1347 1348
					GFP_KERNEL);
		if (sattr->name == NULL)
			goto out;
		sect_attrs->nsections++;
1349
		sysfs_attr_init(&sattr->mattr.attr);
L
Linus Torvalds 已提交
1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363
		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:
1364
	free_sect_attrs(sect_attrs);
L
Linus Torvalds 已提交
1365 1366 1367 1368 1369 1370 1371 1372 1373
}

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. */
1374
		free_sect_attrs(mod->sect_attrs);
L
Linus Torvalds 已提交
1375 1376 1377 1378
		mod->sect_attrs = NULL;
	}
}

R
Roland McGrath 已提交
1379 1380 1381 1382 1383 1384 1385 1386 1387 1388
/*
 * /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];
};

1389
static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
R
Roland McGrath 已提交
1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406
				 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]);
1407
		kobject_put(notes_attrs->dir);
R
Roland McGrath 已提交
1408 1409 1410 1411
	}
	kfree(notes_attrs);
}

R
Rusty Russell 已提交
1412
static void add_notes_attrs(struct module *mod, const struct load_info *info)
R
Roland McGrath 已提交
1413 1414 1415 1416 1417
{
	unsigned int notes, loaded, i;
	struct module_notes_attrs *notes_attrs;
	struct bin_attribute *nattr;

1418 1419 1420 1421
	/* failed to create section attributes, so can't create notes */
	if (!mod->sect_attrs)
		return;

R
Roland McGrath 已提交
1422 1423
	/* Count notes sections and allocate structures.  */
	notes = 0;
R
Rusty Russell 已提交
1424 1425 1426
	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]) &&
		    (info->sechdrs[i].sh_type == SHT_NOTE))
R
Roland McGrath 已提交
1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439
			++notes;

	if (notes == 0)
		return;

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

	notes_attrs->notes = notes;
	nattr = &notes_attrs->attrs[0];
R
Rusty Russell 已提交
1440 1441
	for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
		if (sect_empty(&info->sechdrs[i]))
R
Roland McGrath 已提交
1442
			continue;
R
Rusty Russell 已提交
1443
		if (info->sechdrs[i].sh_type == SHT_NOTE) {
1444
			sysfs_bin_attr_init(nattr);
R
Roland McGrath 已提交
1445 1446
			nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
			nattr->attr.mode = S_IRUGO;
R
Rusty Russell 已提交
1447 1448
			nattr->size = info->sechdrs[i].sh_size;
			nattr->private = (void *) info->sechdrs[i].sh_addr;
R
Roland McGrath 已提交
1449 1450 1451 1452 1453 1454
			nattr->read = module_notes_read;
			++nattr;
		}
		++loaded;
	}

1455
	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
R
Roland McGrath 已提交
1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476
	if (!notes_attrs->dir)
		goto out;

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

	mod->notes_attrs = notes_attrs;
	return;

  out:
	free_notes_attrs(notes_attrs, i);
}

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

L
Linus Torvalds 已提交
1477
#else
1478

R
Rusty Russell 已提交
1479 1480
static inline void add_sect_attrs(struct module *mod,
				  const struct load_info *info)
L
Linus Torvalds 已提交
1481 1482 1483 1484 1485 1486
{
}

static inline void remove_sect_attrs(struct module *mod)
{
}
R
Roland McGrath 已提交
1487

R
Rusty Russell 已提交
1488 1489
static inline void add_notes_attrs(struct module *mod,
				   const struct load_info *info)
R
Roland McGrath 已提交
1490 1491 1492 1493 1494 1495
{
}

static inline void remove_notes_attrs(struct module *mod)
{
}
R
Rusty Russell 已提交
1496
#endif /* CONFIG_KALLSYMS */
L
Linus Torvalds 已提交
1497

1498 1499 1500 1501 1502 1503
static void add_usage_links(struct module *mod)
{
#ifdef CONFIG_MODULE_UNLOAD
	struct module_use *use;
	int nowarn;

1504
	mutex_lock(&module_mutex);
1505 1506 1507 1508
	list_for_each_entry(use, &mod->target_list, target_list) {
		nowarn = sysfs_create_link(use->target->holders_dir,
					   &mod->mkobj.kobj, mod->name);
	}
1509
	mutex_unlock(&module_mutex);
1510 1511 1512 1513 1514 1515 1516 1517
#endif
}

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

1518
	mutex_lock(&module_mutex);
1519 1520
	list_for_each_entry(use, &mod->target_list, target_list)
		sysfs_remove_link(use->target->holders_dir, mod->name);
1521
	mutex_unlock(&module_mutex);
1522 1523 1524
#endif
}

1525
static int module_add_modinfo_attrs(struct module *mod)
1526 1527
{
	struct module_attribute *attr;
1528
	struct module_attribute *temp_attr;
1529 1530 1531
	int error = 0;
	int i;

1532 1533 1534 1535 1536 1537 1538
	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;
1539 1540
	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
		if (!attr->test ||
1541 1542
		    (attr->test && attr->test(mod))) {
			memcpy(temp_attr, attr, sizeof(*temp_attr));
1543
			sysfs_attr_init(&temp_attr->attr);
1544 1545
			error = sysfs_create_file(&mod->mkobj.kobj,
					&temp_attr->attr);
1546 1547
			++temp_attr;
		}
1548 1549 1550 1551
	}
	return error;
}

1552
static void module_remove_modinfo_attrs(struct module *mod)
1553 1554 1555 1556
{
	struct module_attribute *attr;
	int i;

1557 1558 1559 1560
	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
		/* pick a field to test for end of list */
		if (!attr->attr.name)
			break;
1561
		sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1562 1563
		if (attr->free)
			attr->free(mod);
1564
	}
1565
	kfree(mod->modinfo_attrs);
1566
}
L
Linus Torvalds 已提交
1567

1568 1569 1570 1571 1572 1573 1574 1575
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);
}

1576
static int mod_sysfs_init(struct module *mod)
L
Linus Torvalds 已提交
1577 1578
{
	int err;
1579
	struct kobject *kobj;
L
Linus Torvalds 已提交
1580

1581
	if (!module_sysfs_initialized) {
A
Andrew Morton 已提交
1582
		pr_err("%s: module sysfs not initialized\n", mod->name);
1583 1584 1585
		err = -EINVAL;
		goto out;
	}
1586 1587 1588

	kobj = kset_find_obj(module_kset, mod->name);
	if (kobj) {
A
Andrew Morton 已提交
1589
		pr_err("%s: module is already loaded\n", mod->name);
1590 1591 1592 1593 1594
		kobject_put(kobj);
		err = -EINVAL;
		goto out;
	}

L
Linus Torvalds 已提交
1595
	mod->mkobj.mod = mod;
1596

1597 1598 1599 1600 1601
	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)
1602
		mod_kobject_put(mod);
K
Kay Sievers 已提交
1603

1604
	/* delay uevent until full sysfs population */
K
Kay Sievers 已提交
1605 1606 1607 1608
out:
	return err;
}

1609
static int mod_sysfs_setup(struct module *mod,
R
Rusty Russell 已提交
1610
			   const struct load_info *info,
K
Kay Sievers 已提交
1611 1612 1613 1614 1615
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	int err;

1616 1617 1618 1619
	err = mod_sysfs_init(mod);
	if (err)
		goto out;

1620
	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1621 1622
	if (!mod->holders_dir) {
		err = -ENOMEM;
K
Kay Sievers 已提交
1623
		goto out_unreg;
1624
	}
K
Kay Sievers 已提交
1625

L
Linus Torvalds 已提交
1626 1627
	err = module_param_sysfs_setup(mod, kparam, num_params);
	if (err)
K
Kay Sievers 已提交
1628
		goto out_unreg_holders;
L
Linus Torvalds 已提交
1629

1630 1631
	err = module_add_modinfo_attrs(mod);
	if (err)
1632
		goto out_unreg_param;
1633

1634
	add_usage_links(mod);
R
Rusty Russell 已提交
1635 1636
	add_sect_attrs(mod, info);
	add_notes_attrs(mod, info);
1637

1638
	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
L
Linus Torvalds 已提交
1639 1640
	return 0;

1641 1642
out_unreg_param:
	module_param_sysfs_remove(mod);
K
Kay Sievers 已提交
1643
out_unreg_holders:
1644
	kobject_put(mod->holders_dir);
K
Kay Sievers 已提交
1645
out_unreg:
1646
	mod_kobject_put(mod);
1647
out:
L
Linus Torvalds 已提交
1648 1649
	return err;
}
1650 1651 1652

static void mod_sysfs_fini(struct module *mod)
{
R
Rusty Russell 已提交
1653 1654
	remove_notes_attrs(mod);
	remove_sect_attrs(mod);
1655
	mod_kobject_put(mod);
1656 1657
}

R
Rusty Russell 已提交
1658
#else /* !CONFIG_SYSFS */
1659

R
Rusty Russell 已提交
1660 1661
static int mod_sysfs_setup(struct module *mod,
			   const struct load_info *info,
1662 1663 1664 1665 1666 1667
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	return 0;
}

1668 1669 1670 1671
static void mod_sysfs_fini(struct module *mod)
{
}

1672 1673 1674 1675
static void module_remove_modinfo_attrs(struct module *mod)
{
}

1676 1677 1678 1679
static void del_usage_links(struct module *mod)
{
}

1680
#endif /* CONFIG_SYSFS */
L
Linus Torvalds 已提交
1681

1682
static void mod_sysfs_teardown(struct module *mod)
L
Linus Torvalds 已提交
1683
{
1684
	del_usage_links(mod);
1685
	module_remove_modinfo_attrs(mod);
L
Linus Torvalds 已提交
1686
	module_param_sysfs_remove(mod);
1687 1688
	kobject_put(mod->mkobj.drivers_dir);
	kobject_put(mod->holders_dir);
1689
	mod_sysfs_fini(mod);
L
Linus Torvalds 已提交
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 1727 1728 1729 1730 1731 1732 1733 1734 1735
#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);
	}
}

1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753
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);
1754 1755 1756
}

/* Iterate through all modules and set each module's text as RW */
1757
void set_all_modules_text_rw(void)
1758 1759 1760 1761 1762
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1763 1764
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779
		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 */
1780
void set_all_modules_text_ro(void)
1781 1782 1783 1784 1785
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
1786 1787
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802
		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) { }
1803 1804
static void unset_module_core_ro_nx(struct module *mod) { }
static void unset_module_init_ro_nx(struct module *mod) { }
1805 1806
#endif

1807
void __weak module_memfree(void *module_region)
1808 1809 1810 1811 1812 1813 1814 1815
{
	vfree(module_region);
}

void __weak module_arch_cleanup(struct module *mod)
{
}

1816 1817 1818 1819
void __weak module_arch_freeing_init(struct module *mod)
{
}

1820
/* Free a module, remove from lists, etc. */
L
Linus Torvalds 已提交
1821 1822
static void free_module(struct module *mod)
{
1823 1824
	trace_module_free(mod);

1825
	mod_sysfs_teardown(mod);
L
Linus Torvalds 已提交
1826

1827 1828
	/* We leave it in list to prevent duplicate loads, but make sure
	 * that noone uses it while it's being deconstructed. */
1829
	mutex_lock(&module_mutex);
1830
	mod->state = MODULE_STATE_UNFORMED;
1831
	mutex_unlock(&module_mutex);
1832

1833 1834 1835
	/* Remove dynamic debug info */
	ddebug_remove_module(mod->name);

L
Linus Torvalds 已提交
1836 1837 1838 1839 1840 1841
	/* Arch-specific cleanup. */
	module_arch_cleanup(mod);

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

1842 1843 1844
	/* Free any allocated parameters. */
	destroy_params(mod->kp, mod->num_kp);

1845 1846
	/* Now we can delete it from the lists */
	mutex_lock(&module_mutex);
1847 1848
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
1849
	/* Remove this module from bug list, this uses list_del_rcu */
1850
	module_bug_cleanup(mod);
1851 1852
	/* Wait for RCU synchronizing before releasing mod->list and buglist. */
	synchronize_rcu();
1853 1854
	mutex_unlock(&module_mutex);

L
Linus Torvalds 已提交
1855
	/* This may be NULL, but that's OK */
1856
	unset_module_init_ro_nx(mod);
1857
	module_arch_freeing_init(mod);
1858
	module_memfree(mod->module_init);
L
Linus Torvalds 已提交
1859
	kfree(mod->args);
1860
	percpu_modfree(mod);
1861

I
Ingo Molnar 已提交
1862 1863 1864
	/* Free lock-classes: */
	lockdep_free_key_range(mod->module_core, mod->core_size);

L
Linus Torvalds 已提交
1865
	/* Finally, free the core (containing the module structure) */
1866
	unset_module_core_ro_nx(mod);
1867
	module_memfree(mod->module_core);
1868 1869 1870 1871

#ifdef CONFIG_MPU
	update_protections(current->mm);
#endif
L
Linus Torvalds 已提交
1872 1873 1874 1875 1876
}

void *__symbol_get(const char *symbol)
{
	struct module *owner;
1877
	const struct kernel_symbol *sym;
L
Linus Torvalds 已提交
1878

R
Rusty Russell 已提交
1879
	preempt_disable();
1880 1881 1882
	sym = find_symbol(symbol, &owner, NULL, true, true);
	if (sym && strong_try_module_get(owner))
		sym = NULL;
R
Rusty Russell 已提交
1883
	preempt_enable();
L
Linus Torvalds 已提交
1884

1885
	return sym ? (void *)sym->value : NULL;
L
Linus Torvalds 已提交
1886 1887 1888
}
EXPORT_SYMBOL_GPL(__symbol_get);

1889 1890
/*
 * Ensure that an exported symbol [global namespace] does not already exist
1891
 * in the kernel or in some other module's exported symbol table.
1892 1893
 *
 * You must hold the module_mutex.
1894 1895 1896
 */
static int verify_export_symbols(struct module *mod)
{
1897
	unsigned int i;
1898
	struct module *owner;
1899 1900 1901 1902 1903 1904 1905 1906
	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 },
1907
#ifdef CONFIG_UNUSED_SYMBOLS
1908 1909
		{ mod->unused_syms, mod->num_unused_syms },
		{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1910
#endif
1911
	};
1912

1913 1914
	for (i = 0; i < ARRAY_SIZE(arr); i++) {
		for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1915
			if (find_symbol(s->name, &owner, NULL, true, false)) {
A
Andrew Morton 已提交
1916
				pr_err("%s: exports duplicate symbol %s"
1917 1918 1919 1920
				       " (owned by %s)\n",
				       mod->name, s->name, module_name(owner));
				return -ENOEXEC;
			}
1921
		}
1922 1923
	}
	return 0;
1924 1925
}

1926
/* Change all symbols so that st_value encodes the pointer directly. */
1927 1928 1929 1930
static int simplify_symbols(struct module *mod, const struct load_info *info)
{
	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
	Elf_Sym *sym = (void *)symsec->sh_addr;
L
Linus Torvalds 已提交
1931
	unsigned long secbase;
1932
	unsigned int i;
L
Linus Torvalds 已提交
1933
	int ret = 0;
1934
	const struct kernel_symbol *ksym;
L
Linus Torvalds 已提交
1935

1936 1937 1938
	for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
		const char *name = info->strtab + sym[i].st_name;

L
Linus Torvalds 已提交
1939 1940
		switch (sym[i].st_shndx) {
		case SHN_COMMON:
1941 1942 1943 1944
			/* Ignore common symbols */
			if (!strncmp(name, "__gnu_lto", 9))
				break;

L
Linus Torvalds 已提交
1945 1946
			/* We compiled with -fno-common.  These are not
			   supposed to happen.  */
1947
			pr_debug("Common symbol: %s\n", name);
1948
			pr_warn("%s: please compile with -fno-common\n",
L
Linus Torvalds 已提交
1949 1950 1951 1952 1953 1954
			       mod->name);
			ret = -ENOEXEC;
			break;

		case SHN_ABS:
			/* Don't need to do anything */
1955
			pr_debug("Absolute symbol: 0x%08lx\n",
L
Linus Torvalds 已提交
1956 1957 1958 1959
			       (long)sym[i].st_value);
			break;

		case SHN_UNDEF:
1960
			ksym = resolve_symbol_wait(mod, info, name);
L
Linus Torvalds 已提交
1961
			/* Ok if resolved.  */
1962
			if (ksym && !IS_ERR(ksym)) {
1963
				sym[i].st_value = ksym->value;
L
Linus Torvalds 已提交
1964
				break;
1965 1966
			}

L
Linus Torvalds 已提交
1967
			/* Ok if weak.  */
1968
			if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
L
Linus Torvalds 已提交
1969 1970
				break;

A
Andrew Morton 已提交
1971 1972
			pr_warn("%s: Unknown symbol %s (err %li)\n",
				mod->name, name, PTR_ERR(ksym));
1973
			ret = PTR_ERR(ksym) ?: -ENOENT;
L
Linus Torvalds 已提交
1974 1975 1976 1977
			break;

		default:
			/* Divert to percpu allocation if a percpu var. */
1978
			if (sym[i].st_shndx == info->index.pcpu)
1979
				secbase = (unsigned long)mod_percpu(mod);
L
Linus Torvalds 已提交
1980
			else
1981
				secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
L
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1982 1983 1984 1985 1986 1987 1988 1989
			sym[i].st_value += secbase;
			break;
		}
	}

	return ret;
}

1990
static int apply_relocations(struct module *mod, const struct load_info *info)
1991 1992 1993 1994 1995
{
	unsigned int i;
	int err = 0;

	/* Now do relocations. */
1996 1997
	for (i = 1; i < info->hdr->e_shnum; i++) {
		unsigned int infosec = info->sechdrs[i].sh_info;
1998 1999

		/* Not a valid relocation section? */
2000
		if (infosec >= info->hdr->e_shnum)
2001 2002 2003
			continue;

		/* Don't bother with non-allocated sections */
2004
		if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2005 2006
			continue;

2007 2008 2009 2010 2011 2012
		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);
2013 2014 2015 2016 2017 2018
		if (err < 0)
			break;
	}
	return err;
}

2019 2020 2021 2022 2023 2024 2025 2026
/* Additional bytes needed by arch in front of individual sections */
unsigned int __weak arch_mod_section_prepend(struct module *mod,
					     unsigned int section)
{
	/* default implementation just returns zero */
	return 0;
}

L
Linus Torvalds 已提交
2027
/* Update size with this section: return offset. */
2028 2029
static long get_offset(struct module *mod, unsigned int *size,
		       Elf_Shdr *sechdr, unsigned int section)
L
Linus Torvalds 已提交
2030 2031 2032
{
	long ret;

2033
	*size += arch_mod_section_prepend(mod, section);
L
Linus Torvalds 已提交
2034 2035 2036 2037 2038 2039 2040 2041 2042
	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. */
2043
static void layout_sections(struct module *mod, struct load_info *info)
L
Linus Torvalds 已提交
2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055
{
	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;

2056 2057
	for (i = 0; i < info->hdr->e_shnum; i++)
		info->sechdrs[i].sh_entsize = ~0UL;
L
Linus Torvalds 已提交
2058

2059
	pr_debug("Core section allocation order:\n");
L
Linus Torvalds 已提交
2060
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2061 2062 2063
		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
2064 2065 2066 2067

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2068
			    || strstarts(sname, ".init"))
L
Linus Torvalds 已提交
2069
				continue;
2070
			s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2071
			pr_debug("\t%s\n", sname);
L
Linus Torvalds 已提交
2072
		}
2073 2074 2075
		switch (m) {
		case 0: /* executable */
			mod->core_size = debug_align(mod->core_size);
L
Linus Torvalds 已提交
2076
			mod->core_text_size = mod->core_size;
2077 2078 2079 2080 2081 2082 2083 2084 2085
			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
2086 2087
	}

2088
	pr_debug("Init section allocation order:\n");
L
Linus Torvalds 已提交
2089
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2090 2091 2092
		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
2093 2094 2095 2096

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2097
			    || !strstarts(sname, ".init"))
L
Linus Torvalds 已提交
2098
				continue;
2099
			s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
L
Linus Torvalds 已提交
2100
					 | INIT_OFFSET_MASK);
2101
			pr_debug("\t%s\n", sname);
L
Linus Torvalds 已提交
2102
		}
2103 2104 2105
		switch (m) {
		case 0: /* executable */
			mod->init_size = debug_align(mod->init_size);
L
Linus Torvalds 已提交
2106
			mod->init_text_size = mod->init_size;
2107 2108 2109 2110 2111 2112 2113 2114 2115
			break;
		case 1: /* RO: text and ro-data */
			mod->init_size = debug_align(mod->init_size);
			mod->init_ro_size = mod->init_size;
			break;
		case 3: /* whole init */
			mod->init_size = debug_align(mod->init_size);
			break;
		}
L
Linus Torvalds 已提交
2116 2117 2118 2119 2120 2121 2122 2123
	}
}

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

2124
	if (!license_is_gpl_compatible(license)) {
A
Andi Kleen 已提交
2125
		if (!test_taint(TAINT_PROPRIETARY_MODULE))
A
Andrew Morton 已提交
2126 2127
			pr_warn("%s: module license '%s' taints kernel.\n",
				mod->name, license);
2128 2129
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
L
Linus Torvalds 已提交
2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151
	}
}

/* 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;
}

2152
static char *get_modinfo(struct load_info *info, const char *tag)
L
Linus Torvalds 已提交
2153 2154 2155
{
	char *p;
	unsigned int taglen = strlen(tag);
2156 2157
	Elf_Shdr *infosec = &info->sechdrs[info->index.info];
	unsigned long size = infosec->sh_size;
L
Linus Torvalds 已提交
2158

2159
	for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
L
Linus Torvalds 已提交
2160 2161 2162 2163 2164 2165
		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
			return p + taglen + 1;
	}
	return NULL;
}

2166
static void setup_modinfo(struct module *mod, struct load_info *info)
2167 2168 2169 2170 2171 2172
{
	struct module_attribute *attr;
	int i;

	for (i = 0; (attr = modinfo_attrs[i]); i++) {
		if (attr->setup)
2173
			attr->setup(mod, get_modinfo(info, attr->attr.name));
2174 2175 2176
	}
}

2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187
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
2188
#ifdef CONFIG_KALLSYMS
2189 2190 2191 2192 2193 2194

/* 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)
{
2195 2196
	return bsearch(name, start, stop - start,
			sizeof(struct kernel_symbol), cmp_name);
2197 2198
}

2199 2200
static int is_exported(const char *name, unsigned long value,
		       const struct module *mod)
L
Linus Torvalds 已提交
2201
{
2202 2203 2204
	const struct kernel_symbol *ks;
	if (!mod)
		ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2205
	else
2206 2207
		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
	return ks != NULL && ks->value == value;
L
Linus Torvalds 已提交
2208 2209 2210
}

/* As per nm */
2211
static char elf_type(const Elf_Sym *sym, const struct load_info *info)
L
Linus Torvalds 已提交
2212
{
2213 2214
	const Elf_Shdr *sechdrs = info->sechdrs;

L
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2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243
	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';
	}
2244 2245
	if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
		      ".debug")) {
L
Linus Torvalds 已提交
2246
		return 'n';
2247
	}
L
Linus Torvalds 已提交
2248 2249 2250
	return '?';
}

2251
static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2252
			unsigned int shnum)
2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271
{
	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;
}

2272 2273 2274 2275 2276 2277 2278
/*
 * 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>.
 */
2279
static void layout_symtab(struct module *mod, struct load_info *info)
2280
{
2281 2282
	Elf_Shdr *symsect = info->sechdrs + info->index.sym;
	Elf_Shdr *strsect = info->sechdrs + info->index.str;
2283
	const Elf_Sym *src;
2284
	unsigned int i, nsrc, ndst, strtab_size = 0;
2285 2286 2287 2288

	/* 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,
2289
					 info->index.sym) | INIT_OFFSET_MASK;
2290
	pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2291

2292
	src = (void *)info->hdr + symsect->sh_offset;
2293
	nsrc = symsect->sh_size / sizeof(*src);
2294

2295
	/* Compute total space required for the core symbols' strtab. */
2296 2297 2298 2299
	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;
2300
			ndst++;
2301
		}
2302
	}
2303 2304

	/* Append room for core symbols at end of core part. */
2305
	info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2306 2307
	info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
	mod->core_size += strtab_size;
2308

2309 2310 2311
	/* 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,
2312
					 info->index.str) | INIT_OFFSET_MASK;
2313
	pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2314 2315
}

2316
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2317
{
2318 2319 2320
	unsigned int i, ndst;
	const Elf_Sym *src;
	Elf_Sym *dst;
2321
	char *s;
2322
	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
L
Linus Torvalds 已提交
2323

2324 2325
	mod->symtab = (void *)symsec->sh_addr;
	mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2326 2327
	/* 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
2328 2329 2330

	/* Set types up while we still have access to sections. */
	for (i = 0; i < mod->num_symtab; i++)
2331
		mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2332

R
Rusty Russell 已提交
2333
	mod->core_symtab = dst = mod->module_core + info->symoffs;
2334
	mod->core_strtab = s = mod->module_core + info->stroffs;
2335
	src = mod->symtab;
2336 2337 2338 2339 2340 2341 2342 2343
	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;
		}
2344 2345
	}
	mod->core_num_syms = ndst;
L
Linus Torvalds 已提交
2346 2347
}
#else
2348
static inline void layout_symtab(struct module *mod, struct load_info *info)
2349 2350
{
}
2351

2352
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2353 2354 2355 2356
{
}
#endif /* CONFIG_KALLSYMS */

2357
static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2358
{
2359 2360
	if (!debug)
		return;
2361 2362
#ifdef CONFIG_DYNAMIC_DEBUG
	if (ddebug_add_module(debug, num, debug->modname))
A
Andrew Morton 已提交
2363 2364
		pr_err("dynamic debug error adding module: %s\n",
			debug->modname);
2365
#endif
R
Rusty Russell 已提交
2366
}
2367

2368 2369 2370 2371 2372 2373
static void dynamic_debug_remove(struct _ddebug *debug)
{
	if (debug)
		ddebug_remove_module(debug->modname);
}

2374 2375
void * __weak module_alloc(unsigned long size)
{
R
Rusty Russell 已提交
2376
	return vmalloc_exec(size);
2377 2378
}

2379 2380 2381 2382 2383
static void *module_alloc_update_bounds(unsigned long size)
{
	void *ret = module_alloc(size);

	if (ret) {
2384
		mutex_lock(&module_mutex);
2385 2386 2387 2388 2389
		/* 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;
2390
		mutex_unlock(&module_mutex);
2391 2392 2393 2394
	}
	return ret;
}

C
Catalin Marinas 已提交
2395
#ifdef CONFIG_DEBUG_KMEMLEAK
2396 2397
static void kmemleak_load_module(const struct module *mod,
				 const struct load_info *info)
C
Catalin Marinas 已提交
2398 2399 2400 2401
{
	unsigned int i;

	/* only scan the sections containing data */
2402
	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
C
Catalin Marinas 已提交
2403

2404
	for (i = 1; i < info->hdr->e_shnum; i++) {
2405 2406 2407 2408
		/* Scan all writable sections that's not executable */
		if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
		    !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
		    (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
C
Catalin Marinas 已提交
2409 2410
			continue;

2411 2412
		kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
				   info->sechdrs[i].sh_size, GFP_KERNEL);
C
Catalin Marinas 已提交
2413 2414 2415
	}
}
#else
2416 2417
static inline void kmemleak_load_module(const struct module *mod,
					const struct load_info *info)
C
Catalin Marinas 已提交
2418 2419 2420 2421
{
}
#endif

R
Rusty Russell 已提交
2422
#ifdef CONFIG_MODULE_SIG
2423
static int module_sig_check(struct load_info *info)
R
Rusty Russell 已提交
2424 2425
{
	int err = -ENOKEY;
2426 2427
	const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
	const void *mod = info->hdr;
2428

2429 2430
	if (info->len > markerlen &&
	    memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2431
		/* We truncate the module to discard the signature */
2432 2433
		info->len -= markerlen;
		err = mod_verify_sig(mod, &info->len);
R
Rusty Russell 已提交
2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447
	}

	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 */
2448
static int module_sig_check(struct load_info *info)
R
Rusty Russell 已提交
2449 2450 2451 2452 2453
{
	return 0;
}
#endif /* !CONFIG_MODULE_SIG */

2454 2455
/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
static int elf_header_check(struct load_info *info)
2456
{
2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469
	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;
2470

2471 2472 2473 2474 2475 2476
	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)
2477 2478 2479
{
	int err;

2480 2481
	info->len = len;
	if (info->len < sizeof(*(info->hdr)))
2482 2483
		return -ENOEXEC;

2484 2485 2486 2487
	err = security_kernel_module_from_file(NULL);
	if (err)
		return err;

2488
	/* Suck in entire file: we'll want most of it. */
2489 2490
	info->hdr = vmalloc(info->len);
	if (!info->hdr)
2491 2492
		return -ENOMEM;

2493 2494 2495
	if (copy_from_user(info->hdr, umod, info->len) != 0) {
		vfree(info->hdr);
		return -EFAULT;
2496 2497
	}

2498 2499 2500 2501 2502 2503
	return 0;
}

/* Sets info->hdr and info->len. */
static int copy_module_from_fd(int fd, struct load_info *info)
{
A
Al Viro 已提交
2504
	struct fd f = fdget(fd);
2505 2506 2507 2508 2509
	int err;
	struct kstat stat;
	loff_t pos;
	ssize_t bytes = 0;

A
Al Viro 已提交
2510
	if (!f.file)
2511 2512
		return -ENOEXEC;

A
Al Viro 已提交
2513
	err = security_kernel_module_from_file(f.file);
R
Rusty Russell 已提交
2514
	if (err)
2515
		goto out;
R
Rusty Russell 已提交
2516

A
Al Viro 已提交
2517
	err = vfs_getattr(&f.file->f_path, &stat);
R
Rusty Russell 已提交
2518
	if (err)
2519
		goto out;
2520

2521 2522 2523
	if (stat.size > INT_MAX) {
		err = -EFBIG;
		goto out;
2524
	}
2525 2526 2527 2528 2529 2530 2531

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

2532 2533 2534 2535
	info->hdr = vmalloc(stat.size);
	if (!info->hdr) {
		err = -ENOMEM;
		goto out;
2536
	}
R
Rusty Russell 已提交
2537

2538 2539
	pos = 0;
	while (pos < stat.size) {
A
Al Viro 已提交
2540
		bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551
				    stat.size - pos);
		if (bytes < 0) {
			vfree(info->hdr);
			err = bytes;
			goto out;
		}
		if (bytes == 0)
			break;
		pos += bytes;
	}
	info->len = pos;
2552

2553
out:
A
Al Viro 已提交
2554
	fdput(f);
2555 2556 2557
	return err;
}

R
Rusty Russell 已提交
2558 2559 2560 2561 2562
static void free_copy(struct load_info *info)
{
	vfree(info->hdr);
}

2563
static int rewrite_section_headers(struct load_info *info, int flags)
2564 2565 2566 2567 2568 2569 2570 2571 2572 2573
{
	unsigned int i;

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

	for (i = 1; i < info->hdr->e_shnum; i++) {
		Elf_Shdr *shdr = &info->sechdrs[i];
		if (shdr->sh_type != SHT_NOBITS
		    && info->len < shdr->sh_offset + shdr->sh_size) {
A
Andrew Morton 已提交
2574
			pr_err("Module len %lu truncated\n", info->len);
2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587
			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
	}
2588 2589

	/* Track but don't keep modinfo and version sections. */
2590 2591 2592 2593
	if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
		info->index.vers = 0; /* Pretend no __versions section! */
	else
		info->index.vers = find_sec(info, "__versions");
2594
	info->index.info = find_sec(info, ".modinfo");
2595 2596
	info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
	info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2597 2598 2599
	return 0;
}

L
Linus Torvalds 已提交
2600 2601 2602 2603 2604 2605 2606 2607
/*
 * 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).
 */
2608
static struct module *setup_load_info(struct load_info *info, int flags)
L
Linus Torvalds 已提交
2609 2610
{
	unsigned int i;
2611
	int err;
L
Linus Torvalds 已提交
2612 2613 2614 2615
	struct module *mod;

	/* Set up the convenience variables */
	info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2616 2617
	info->secstrings = (void *)info->hdr
		+ info->sechdrs[info->hdr->e_shstrndx].sh_offset;
L
Linus Torvalds 已提交
2618

2619
	err = rewrite_section_headers(info, flags);
2620 2621
	if (err)
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2622

2623 2624
	/* Find internal symbols and strings. */
	for (i = 1; i < info->hdr->e_shnum; i++) {
L
Linus Torvalds 已提交
2625 2626 2627
		if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
			info->index.sym = i;
			info->index.str = info->sechdrs[i].sh_link;
2628 2629 2630
			info->strtab = (char *)info->hdr
				+ info->sechdrs[info->index.str].sh_offset;
			break;
L
Linus Torvalds 已提交
2631 2632 2633
		}
	}

2634
	info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
L
Linus Torvalds 已提交
2635
	if (!info->index.mod) {
A
Andrew Morton 已提交
2636
		pr_warn("No module found in object\n");
L
Linus Torvalds 已提交
2637 2638 2639 2640 2641 2642
		return ERR_PTR(-ENOEXEC);
	}
	/* This is temporary: point mod into copy of data. */
	mod = (void *)info->sechdrs[info->index.mod].sh_addr;

	if (info->index.sym == 0) {
A
Andrew Morton 已提交
2643
		pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
L
Linus Torvalds 已提交
2644 2645 2646
		return ERR_PTR(-ENOEXEC);
	}

2647
	info->index.pcpu = find_pcpusec(info);
L
Linus Torvalds 已提交
2648 2649 2650 2651 2652 2653 2654 2655

	/* 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;
}

2656
static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2657
{
2658
	const char *modmagic = get_modinfo(info, "vermagic");
2659 2660
	int err;

2661 2662 2663
	if (flags & MODULE_INIT_IGNORE_VERMAGIC)
		modmagic = NULL;

2664 2665 2666 2667 2668
	/* This is allowed: modprobe --force will invalidate it. */
	if (!modmagic) {
		err = try_to_force_load(mod, "bad vermagic");
		if (err)
			return err;
2669
	} else if (!same_magic(modmagic, vermagic, info->index.vers)) {
A
Andrew Morton 已提交
2670
		pr_err("%s: version magic '%s' should be '%s'\n",
2671 2672 2673 2674
		       mod->name, modmagic, vermagic);
		return -ENOEXEC;
	}

2675
	if (!get_modinfo(info, "intree"))
2676
		add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2677

2678
	if (get_modinfo(info, "staging")) {
2679
		add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
A
Andrew Morton 已提交
2680 2681
		pr_warn("%s: module is from the staging directory, the quality "
			"is unknown, you have been warned.\n", mod->name);
2682
	}
2683 2684

	/* Set up license info based on the info section */
2685
	set_license(mod, get_modinfo(info, "license"));
2686

2687 2688 2689
	return 0;
}

2690
static int find_module_sections(struct module *mod, struct load_info *info)
L
Linus Torvalds 已提交
2691
{
2692
	mod->kp = section_objs(info, "__param",
L
Linus Torvalds 已提交
2693
			       sizeof(*mod->kp), &mod->num_kp);
2694
	mod->syms = section_objs(info, "__ksymtab",
L
Linus Torvalds 已提交
2695
				 sizeof(*mod->syms), &mod->num_syms);
2696 2697
	mod->crcs = section_addr(info, "__kcrctab");
	mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
L
Linus Torvalds 已提交
2698 2699
				     sizeof(*mod->gpl_syms),
				     &mod->num_gpl_syms);
2700 2701
	mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
	mod->gpl_future_syms = section_objs(info,
L
Linus Torvalds 已提交
2702 2703 2704
					    "__ksymtab_gpl_future",
					    sizeof(*mod->gpl_future_syms),
					    &mod->num_gpl_future_syms);
2705
	mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
L
Linus Torvalds 已提交
2706 2707

#ifdef CONFIG_UNUSED_SYMBOLS
2708
	mod->unused_syms = section_objs(info, "__ksymtab_unused",
L
Linus Torvalds 已提交
2709 2710
					sizeof(*mod->unused_syms),
					&mod->num_unused_syms);
2711 2712
	mod->unused_crcs = section_addr(info, "__kcrctab_unused");
	mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
L
Linus Torvalds 已提交
2713 2714
					    sizeof(*mod->unused_gpl_syms),
					    &mod->num_unused_gpl_syms);
2715
	mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
L
Linus Torvalds 已提交
2716 2717
#endif
#ifdef CONFIG_CONSTRUCTORS
2718
	mod->ctors = section_objs(info, ".ctors",
L
Linus Torvalds 已提交
2719
				  sizeof(*mod->ctors), &mod->num_ctors);
2720 2721 2722 2723 2724 2725 2726 2727
	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.
		 */
2728
		pr_warn("%s: has both .ctors and .init_array.\n",
2729 2730 2731
		       mod->name);
		return -EINVAL;
	}
L
Linus Torvalds 已提交
2732 2733 2734
#endif

#ifdef CONFIG_TRACEPOINTS
2735 2736 2737
	mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
					     sizeof(*mod->tracepoints_ptrs),
					     &mod->num_tracepoints);
L
Linus Torvalds 已提交
2738
#endif
2739 2740 2741 2742 2743
#ifdef HAVE_JUMP_LABEL
	mod->jump_entries = section_objs(info, "__jump_table",
					sizeof(*mod->jump_entries),
					&mod->num_jump_entries);
#endif
L
Linus Torvalds 已提交
2744
#ifdef CONFIG_EVENT_TRACING
2745
	mod->trace_events = section_objs(info, "_ftrace_events",
L
Linus Torvalds 已提交
2746 2747 2748
					 sizeof(*mod->trace_events),
					 &mod->num_trace_events);
#endif
2749 2750 2751 2752 2753
#ifdef CONFIG_TRACING
	mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
					 sizeof(*mod->trace_bprintk_fmt_start),
					 &mod->num_trace_bprintk_fmt);
#endif
L
Linus Torvalds 已提交
2754 2755
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
	/* sechdrs[0].sh_size is always zero */
2756
	mod->ftrace_callsites = section_objs(info, "__mcount_loc",
L
Linus Torvalds 已提交
2757 2758 2759
					     sizeof(*mod->ftrace_callsites),
					     &mod->num_ftrace_callsites);
#endif
2760

2761 2762 2763
	mod->extable = section_objs(info, "__ex_table",
				    sizeof(*mod->extable), &mod->num_exentries);

2764
	if (section_addr(info, "__obsparm"))
A
Andrew Morton 已提交
2765
		pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2766 2767 2768

	info->debug = section_objs(info, "__verbose",
				   sizeof(*info->debug), &info->num_debug);
2769 2770

	return 0;
L
Linus Torvalds 已提交
2771 2772
}

2773
static int move_module(struct module *mod, struct load_info *info)
2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786
{
	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)
R
Rusty Russell 已提交
2787
		return -ENOMEM;
2788 2789 2790 2791

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

R
Rusty Russell 已提交
2792 2793 2794 2795 2796 2797 2798 2799 2800 2801
	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) {
2802
			module_memfree(mod->module_core);
R
Rusty Russell 已提交
2803 2804 2805 2806 2807 2808
			return -ENOMEM;
		}
		memset(ptr, 0, mod->init_size);
		mod->module_init = ptr;
	} else
		mod->module_init = NULL;
2809 2810

	/* Transfer each section which specifies SHF_ALLOC */
2811
	pr_debug("final section addresses:\n");
2812
	for (i = 0; i < info->hdr->e_shnum; i++) {
2813
		void *dest;
2814
		Elf_Shdr *shdr = &info->sechdrs[i];
2815

2816
		if (!(shdr->sh_flags & SHF_ALLOC))
2817 2818
			continue;

2819
		if (shdr->sh_entsize & INIT_OFFSET_MASK)
2820
			dest = mod->module_init
2821
				+ (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2822
		else
2823
			dest = mod->module_core + shdr->sh_entsize;
2824

2825 2826
		if (shdr->sh_type != SHT_NOBITS)
			memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2827
		/* Update sh_addr to point to copy in image. */
2828
		shdr->sh_addr = (unsigned long)dest;
2829 2830
		pr_debug("\t0x%lx %s\n",
			 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2831
	}
R
Rusty Russell 已提交
2832 2833

	return 0;
2834 2835
}

2836
static int check_module_license_and_versions(struct module *mod)
2837 2838 2839 2840 2841 2842 2843
{
	/*
	 * 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)
2844
		add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2845 2846 2847

	/* driverloader was caught wrongly pretending to be under GPL */
	if (strcmp(mod->name, "driverloader") == 0)
2848 2849
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
2850

2851 2852
	/* lve claims to be GPL but upstream won't provide source */
	if (strcmp(mod->name, "lve") == 0)
2853 2854
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
				 LOCKDEP_NOW_UNRELIABLE);
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 2886 2887 2888 2889 2890 2891 2892 2893 2894
#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);
}

2895 2896 2897 2898 2899 2900 2901 2902
int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
				     Elf_Shdr *sechdrs,
				     char *secstrings,
				     struct module *mod)
{
	return 0;
}

2903
static struct module *layout_and_allocate(struct load_info *info, int flags)
L
Linus Torvalds 已提交
2904
{
R
Rusty Russell 已提交
2905
	/* Module within temporary copy. */
L
Linus Torvalds 已提交
2906
	struct module *mod;
R
Rusty Russell 已提交
2907
	int err;
2908

2909
	mod = setup_load_info(info, flags);
R
Rusty Russell 已提交
2910 2911
	if (IS_ERR(mod))
		return mod;
L
Linus Torvalds 已提交
2912

2913
	err = check_modinfo(mod, info, flags);
2914 2915
	if (err)
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2916 2917

	/* Allow arches to frob section contents and sizes.  */
2918 2919
	err = module_frob_arch_sections(info->hdr, info->sechdrs,
					info->secstrings, mod);
L
Linus Torvalds 已提交
2920
	if (err < 0)
2921
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2922

2923 2924
	/* 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
2925 2926 2927 2928

	/* 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. */
2929 2930
	layout_sections(mod, info);
	layout_symtab(mod, info);
L
Linus Torvalds 已提交
2931

2932
	/* Allocate and move to the final place */
2933
	err = move_module(mod, info);
R
Rusty Russell 已提交
2934
	if (err)
2935
		return ERR_PTR(err);
R
Rusty Russell 已提交
2936 2937 2938

	/* Module has been copied to its final place now: return it. */
	mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2939
	kmemleak_load_module(mod, info);
R
Rusty Russell 已提交
2940 2941 2942 2943 2944 2945 2946
	return mod;
}

/* mod is no longer valid after this! */
static void module_deallocate(struct module *mod, struct load_info *info)
{
	percpu_modfree(mod);
2947
	module_arch_freeing_init(mod);
2948 2949
	module_memfree(mod->module_init);
	module_memfree(mod->module_core);
R
Rusty Russell 已提交
2950 2951
}

2952 2953 2954 2955 2956 2957 2958
int __weak module_finalize(const Elf_Ehdr *hdr,
			   const Elf_Shdr *sechdrs,
			   struct module *me)
{
	return 0;
}

2959 2960
static int post_relocation(struct module *mod, const struct load_info *info)
{
2961
	/* Sort exception table now relocations are done. */
2962 2963 2964 2965 2966 2967
	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);

2968
	/* Setup kallsyms-specific fields. */
2969 2970 2971 2972 2973 2974
	add_kallsyms(mod, info);

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

2975 2976 2977 2978 2979 2980 2981
/* 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);
2982
	mod = find_module_all(name, strlen(name), true);
2983 2984
	ret = !mod || mod->state == MODULE_STATE_LIVE
		|| mod->state == MODULE_STATE_GOING;
2985 2986 2987 2988 2989
	mutex_unlock(&module_mutex);

	return ret;
}

2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000
/* 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
}

3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013
/* For freeing module_init on success, in case kallsyms traversing */
struct mod_initfree {
	struct rcu_head rcu;
	void *module_init;
};

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

3014 3015 3016 3017
/* This is where the real work happens */
static int do_init_module(struct module *mod)
{
	int ret = 0;
3018 3019 3020 3021 3022 3023 3024 3025
	struct mod_initfree *freeinit;

	freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
	if (!freeinit) {
		ret = -ENOMEM;
		goto fail;
	}
	freeinit->module_init = mod->module_init;
3026

3027 3028 3029 3030 3031 3032
	/*
	 * 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;

3033 3034 3035 3036 3037
	do_mod_ctors(mod);
	/* Start the module */
	if (mod->init != NULL)
		ret = do_one_initcall(mod->init);
	if (ret < 0) {
3038
		goto fail_free_freeinit;
3039 3040
	}
	if (ret > 0) {
A
Andrew Morton 已提交
3041 3042 3043 3044
		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__);
3045 3046 3047 3048 3049 3050 3051 3052
		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);

3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071
	/*
	 * 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();
3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082

	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);
3083
	module_arch_freeing_init(mod);
3084 3085 3086 3087
	mod->module_init = NULL;
	mod->init_size = 0;
	mod->init_ro_size = 0;
	mod->init_text_size = 0;
3088 3089 3090 3091 3092 3093 3094
	/*
	 * We want to free module_init, but be aware that kallsyms may be
	 * walking this with preempt disabled.  In all the failure paths,
	 * we call synchronize_rcu/synchronize_sched, but we don't want
	 * to slow down the success path, so use actual RCU here.
	 */
	call_rcu(&freeinit->rcu, do_free_init);
3095 3096 3097 3098
	mutex_unlock(&module_mutex);
	wake_up_all(&module_wq);

	return 0;
3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111

fail_free_freeinit:
	kfree(freeinit);
fail:
	/* Try to protect us from buggy refcounters. */
	mod->state = MODULE_STATE_GOING;
	synchronize_sched();
	module_put(mod);
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
	free_module(mod);
	wake_up_all(&module_wq);
	return ret;
3112 3113 3114 3115 3116 3117 3118 3119 3120 3121
}

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

	return 0;
}

3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147
/*
 * 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;
}

3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161
/*
 * 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);
3162 3163
	old = find_module_all(mod->name, strlen(mod->name), true);
	if (old != NULL) {
3164 3165 3166 3167
		if (old->state == MODULE_STATE_COMING
		    || old->state == MODULE_STATE_UNFORMED) {
			/* Wait in case it fails to load. */
			mutex_unlock(&module_mutex);
3168 3169

			err = wait_finished_loading(mod);
3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199
			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);

3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211
	/* 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);

3212 3213 3214
	/* Mark state as coming so strong_try_module_get() ignores us,
	 * but kallsyms etc. can see us. */
	mod->state = MODULE_STATE_COMING;
3215 3216 3217 3218 3219
	mutex_unlock(&module_mutex);

	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_COMING, mod);
	return 0;
3220 3221 3222 3223 3224 3225

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

3226 3227
static int unknown_module_param_cb(char *param, char *val, const char *modname)
{
3228
	/* Check for magic 'dyndbg' arg */
3229
	int ret = ddebug_dyndbg_module_param_cb(param, val, modname);
A
Andrew Morton 已提交
3230 3231
	if (ret != 0)
		pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3232 3233 3234
	return 0;
}

R
Rusty Russell 已提交
3235 3236
/* Allocate and load the module: note that size of section 0 is always
   zero, and we rely on this for optional sections. */
3237 3238
static int load_module(struct load_info *info, const char __user *uargs,
		       int flags)
R
Rusty Russell 已提交
3239
{
3240
	struct module *mod;
R
Rusty Russell 已提交
3241
	long err;
3242
	char *after_dashes;
R
Rusty Russell 已提交
3243

3244 3245 3246
	err = module_sig_check(info);
	if (err)
		goto free_copy;
R
Rusty Russell 已提交
3247

3248
	err = elf_header_check(info);
R
Rusty Russell 已提交
3249
	if (err)
3250
		goto free_copy;
R
Rusty Russell 已提交
3251 3252

	/* Figure out module layout, and allocate all the memory. */
3253
	mod = layout_and_allocate(info, flags);
3254 3255
	if (IS_ERR(mod)) {
		err = PTR_ERR(mod);
R
Rusty Russell 已提交
3256
		goto free_copy;
L
Linus Torvalds 已提交
3257 3258
	}

3259 3260 3261
	/* Reserve our place in the list. */
	err = add_unformed_module(mod);
	if (err)
3262 3263
		goto free_module;

R
Rusty Russell 已提交
3264
#ifdef CONFIG_MODULE_SIG
3265
	mod->sig_ok = info->sig_ok;
3266
	if (!mod->sig_ok) {
A
Andrew Morton 已提交
3267 3268 3269
		pr_notice_once("%s: module verification failed: signature "
			       "and/or  required key missing - tainting "
			       "kernel\n", mod->name);
3270
		add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3271
	}
R
Rusty Russell 已提交
3272 3273
#endif

3274
	/* To avoid stressing percpu allocator, do this once we're unique. */
R
Rusty Russell 已提交
3275
	err = percpu_modalloc(mod, info);
3276 3277 3278
	if (err)
		goto unlink_mod;

3279
	/* Now module is in final location, initialize linked lists, etc. */
3280 3281
	err = module_unload_init(mod);
	if (err)
3282
		goto unlink_mod;
L
Linus Torvalds 已提交
3283

3284 3285
	/* Now we've got everything in the final locations, we can
	 * find optional sections. */
3286 3287 3288
	err = find_module_sections(mod, info);
	if (err)
		goto free_unload;
3289

3290
	err = check_module_license_and_versions(mod);
3291 3292
	if (err)
		goto free_unload;
3293

3294
	/* Set up MODINFO_ATTR fields */
3295
	setup_modinfo(mod, info);
3296

L
Linus Torvalds 已提交
3297
	/* Fix up syms, so that st_value is a pointer to location. */
3298
	err = simplify_symbols(mod, info);
L
Linus Torvalds 已提交
3299
	if (err < 0)
R
Rusty Russell 已提交
3300
		goto free_modinfo;
L
Linus Torvalds 已提交
3301

3302
	err = apply_relocations(mod, info);
3303
	if (err < 0)
R
Rusty Russell 已提交
3304
		goto free_modinfo;
L
Linus Torvalds 已提交
3305

3306
	err = post_relocation(mod, info);
L
Linus Torvalds 已提交
3307
	if (err < 0)
R
Rusty Russell 已提交
3308
		goto free_modinfo;
L
Linus Torvalds 已提交
3309

3310
	flush_module_icache(mod);
3311

3312 3313 3314 3315 3316 3317
	/* Now copy in args */
	mod->args = strndup_user(uargs, ~0UL >> 1);
	if (IS_ERR(mod->args)) {
		err = PTR_ERR(mod->args);
		goto free_arch_cleanup;
	}
R
Rusty Russell 已提交
3318

3319
	dynamic_debug_setup(info->debug, info->num_debug);
3320

3321 3322 3323
	/* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
	ftrace_module_init(mod);

3324 3325 3326
	/* Finally it's fully formed, ready to start executing. */
	err = complete_formation(mod, info);
	if (err)
3327
		goto ddebug_cleanup;
3328

3329
	/* Module is ready to execute: parsing args may do that. */
3330 3331 3332 3333
	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);
3334
		goto bug_cleanup;
3335 3336 3337 3338
	} else if (after_dashes) {
		pr_warn("%s: parameters '%s' after `--' ignored\n",
		       mod->name, after_dashes);
	}
L
Linus Torvalds 已提交
3339

3340
	/* Link in to syfs. */
3341
	err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
L
Linus Torvalds 已提交
3342
	if (err < 0)
3343
		goto bug_cleanup;
3344

3345
	/* Get rid of temporary copy. */
3346
	free_copy(info);
L
Linus Torvalds 已提交
3347 3348

	/* Done! */
3349
	trace_module_load(mod);
3350 3351

	return do_init_module(mod);
L
Linus Torvalds 已提交
3352

3353 3354
 bug_cleanup:
	/* module_bug_cleanup needs module_mutex protection */
3355
	mutex_lock(&module_mutex);
3356
	module_bug_cleanup(mod);
3357
	mutex_unlock(&module_mutex);
3358

3359 3360 3361
	/* Free lock-classes: */
	lockdep_free_key_range(mod->module_core, mod->core_size);

3362 3363 3364 3365
	/* we can't deallocate the module until we clear memory protection */
	unset_module_init_ro_nx(mod);
	unset_module_core_ro_nx(mod);

3366
 ddebug_cleanup:
3367
	dynamic_debug_remove(info->debug);
3368
	synchronize_sched();
3369 3370
	kfree(mod->args);
 free_arch_cleanup:
L
Linus Torvalds 已提交
3371
	module_arch_cleanup(mod);
R
Rusty Russell 已提交
3372
 free_modinfo:
3373
	free_modinfo(mod);
3374
 free_unload:
L
Linus Torvalds 已提交
3375
	module_unload_free(mod);
3376 3377 3378 3379 3380
 unlink_mod:
	mutex_lock(&module_mutex);
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
	wake_up_all(&module_wq);
3381 3382
	/* Wait for RCU synchronizing before releasing mod->list. */
	synchronize_rcu();
3383
	mutex_unlock(&module_mutex);
R
Rusty Russell 已提交
3384
 free_module:
3385
	module_deallocate(mod, info);
R
Rusty Russell 已提交
3386
 free_copy:
3387 3388
	free_copy(info);
	return err;
3389 3390
}

3391 3392
SYSCALL_DEFINE3(init_module, void __user *, umod,
		unsigned long, len, const char __user *, uargs)
L
Linus Torvalds 已提交
3393
{
3394 3395
	int err;
	struct load_info info = { };
L
Linus Torvalds 已提交
3396

3397 3398 3399
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3400

3401 3402
	pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
	       umod, len, uargs);
L
Linus Torvalds 已提交
3403

3404 3405 3406
	err = copy_module_from_user(umod, len, &info);
	if (err)
		return err;
L
Linus Torvalds 已提交
3407

3408
	return load_module(&info, uargs, 0);
3409
}
3410

3411
SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3412 3413 3414
{
	int err;
	struct load_info info = { };
3415

3416 3417 3418
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3419

3420
	pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3421

3422 3423 3424
	if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
		      |MODULE_INIT_IGNORE_VERMAGIC))
		return -EINVAL;
3425

3426 3427 3428
	err = copy_module_from_fd(fd, &info);
	if (err)
		return err;
L
Linus Torvalds 已提交
3429

3430
	return load_module(&info, uargs, flags);
L
Linus Torvalds 已提交
3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444
}

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 $d.
 */
static inline int is_arm_mapping_symbol(const char *str)
{
3445 3446
	if (str[0] == '.' && str[1] == 'L')
		return true;
K
Kyle McMartin 已提交
3447
	return str[0] == '$' && strchr("axtd", str[1])
L
Linus Torvalds 已提交
3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459
	       && (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 */
3460
	if (within_module_init(addr, mod))
L
Linus Torvalds 已提交
3461
		nextval = (unsigned long)mod->module_init+mod->init_text_size;
D
Daniel Walker 已提交
3462
	else
L
Linus Torvalds 已提交
3463 3464
		nextval = (unsigned long)mod->module_core+mod->core_text_size;

L
Lucas De Marchi 已提交
3465
	/* Scan for closest preceding symbol, and next symbol. (ELF
D
Daniel Walker 已提交
3466
	   starts real symbols at 1). */
L
Linus Torvalds 已提交
3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487
	for (i = 1; i < mod->num_symtab; i++) {
		if (mod->symtab[i].st_shndx == SHN_UNDEF)
			continue;

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

	if (!best)
		return NULL;

A
Alexey Dobriyan 已提交
3488 3489 3490 3491
	if (size)
		*size = nextval - mod->symtab[best].st_value;
	if (offset)
		*offset = addr - mod->symtab[best].st_value;
L
Linus Torvalds 已提交
3492 3493 3494
	return mod->strtab + mod->symtab[best].st_name;
}

3495 3496
/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3497
const char *module_address_lookup(unsigned long addr,
3498 3499 3500 3501
			    unsigned long *size,
			    unsigned long *offset,
			    char **modname,
			    char *namebuf)
L
Linus Torvalds 已提交
3502 3503
{
	struct module *mod;
3504
	const char *ret = NULL;
L
Linus Torvalds 已提交
3505

3506
	preempt_disable();
3507
	list_for_each_entry_rcu(mod, &modules, list) {
3508 3509
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3510
		if (within_module(addr, mod)) {
3511 3512
			if (modname)
				*modname = mod->name;
3513 3514
			ret = get_ksymbol(mod, addr, size, offset);
			break;
L
Linus Torvalds 已提交
3515 3516
		}
	}
3517 3518 3519 3520 3521
	/* Make a copy in here where it's safe */
	if (ret) {
		strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
		ret = namebuf;
	}
3522
	preempt_enable();
3523
	return ret;
L
Linus Torvalds 已提交
3524 3525
}

3526 3527 3528 3529
int lookup_module_symbol_name(unsigned long addr, char *symname)
{
	struct module *mod;

3530
	preempt_disable();
3531
	list_for_each_entry_rcu(mod, &modules, list) {
3532 3533
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3534
		if (within_module(addr, mod)) {
3535 3536 3537 3538 3539
			const char *sym;

			sym = get_ksymbol(mod, addr, NULL, NULL);
			if (!sym)
				goto out;
3540
			strlcpy(symname, sym, KSYM_NAME_LEN);
3541
			preempt_enable();
3542 3543 3544 3545
			return 0;
		}
	}
out:
3546
	preempt_enable();
3547 3548 3549
	return -ERANGE;
}

3550 3551 3552 3553 3554
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
			unsigned long *offset, char *modname, char *name)
{
	struct module *mod;

3555
	preempt_disable();
3556
	list_for_each_entry_rcu(mod, &modules, list) {
3557 3558
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3559
		if (within_module(addr, mod)) {
3560 3561 3562 3563 3564 3565
			const char *sym;

			sym = get_ksymbol(mod, addr, size, offset);
			if (!sym)
				goto out;
			if (modname)
3566
				strlcpy(modname, mod->name, MODULE_NAME_LEN);
3567
			if (name)
3568
				strlcpy(name, sym, KSYM_NAME_LEN);
3569
			preempt_enable();
3570 3571 3572 3573
			return 0;
		}
	}
out:
3574
	preempt_enable();
3575 3576 3577
	return -ERANGE;
}

3578 3579
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
3580 3581 3582
{
	struct module *mod;

3583
	preempt_disable();
3584
	list_for_each_entry_rcu(mod, &modules, list) {
3585 3586
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
L
Linus Torvalds 已提交
3587 3588 3589
		if (symnum < mod->num_symtab) {
			*value = mod->symtab[symnum].st_value;
			*type = mod->symtab[symnum].st_info;
3590
			strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3591 3592
				KSYM_NAME_LEN);
			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3593
			*exported = is_exported(name, *value, mod);
3594
			preempt_enable();
3595
			return 0;
L
Linus Torvalds 已提交
3596 3597 3598
		}
		symnum -= mod->num_symtab;
	}
3599
	preempt_enable();
3600
	return -ERANGE;
L
Linus Torvalds 已提交
3601 3602 3603 3604 3605 3606 3607
}

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

	for (i = 0; i < mod->num_symtab; i++)
3608 3609
		if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
		    mod->symtab[i].st_info != 'U')
L
Linus Torvalds 已提交
3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621
			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. */
3622
	preempt_disable();
L
Linus Torvalds 已提交
3623
	if ((colon = strchr(name, ':')) != NULL) {
3624
		if ((mod = find_module_all(name, colon - name, false)) != NULL)
L
Linus Torvalds 已提交
3625 3626
			ret = mod_find_symname(mod, colon+1);
	} else {
3627 3628 3629
		list_for_each_entry_rcu(mod, &modules, list) {
			if (mod->state == MODULE_STATE_UNFORMED)
				continue;
L
Linus Torvalds 已提交
3630 3631
			if ((ret = mod_find_symname(mod, name)) != 0)
				break;
3632
		}
L
Linus Torvalds 已提交
3633
	}
3634
	preempt_enable();
L
Linus Torvalds 已提交
3635 3636
	return ret;
}
3637 3638 3639 3640 3641 3642 3643 3644 3645 3646

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) {
3647 3648
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3649 3650 3651 3652 3653 3654 3655 3656 3657
		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
3658 3659
#endif /* CONFIG_KALLSYMS */

3660
static char *module_flags(struct module *mod, char *buf)
3661 3662 3663
{
	int bx = 0;

3664
	BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3665 3666 3667
	if (mod->taints ||
	    mod->state == MODULE_STATE_GOING ||
	    mod->state == MODULE_STATE_COMING) {
3668
		buf[bx++] = '(';
3669
		bx += module_flags_taint(mod, buf + bx);
3670 3671 3672 3673 3674 3675
		/* 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++] = '+';
3676 3677 3678 3679 3680 3681 3682
		buf[bx++] = ')';
	}
	buf[bx] = '\0';

	return buf;
}

3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696 3697 3698 3699 3700
#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
3701 3702 3703
static int m_show(struct seq_file *m, void *p)
{
	struct module *mod = list_entry(p, struct module, list);
3704 3705
	char buf[8];

3706 3707 3708 3709
	/* We always ignore unformed modules. */
	if (mod->state == MODULE_STATE_UNFORMED)
		return 0;

3710
	seq_printf(m, "%s %u",
L
Linus Torvalds 已提交
3711 3712 3713 3714 3715
		   mod->name, mod->init_size + mod->core_size);
	print_unload_info(m, mod);

	/* Informative for users. */
	seq_printf(m, " %s",
3716 3717
		   mod->state == MODULE_STATE_GOING ? "Unloading" :
		   mod->state == MODULE_STATE_COMING ? "Loading" :
L
Linus Torvalds 已提交
3718 3719
		   "Live");
	/* Used by oprofile and other similar tools. */
3720
	seq_printf(m, " 0x%pK", mod->module_core);
L
Linus Torvalds 已提交
3721

3722 3723
	/* Taints info */
	if (mod->taints)
3724
		seq_printf(m, " %s", module_flags(mod, buf));
3725

3726
	seq_puts(m, "\n");
L
Linus Torvalds 已提交
3727 3728 3729 3730 3731 3732 3733 3734
	return 0;
}

/* Format: modulename size refcount deps address

   Where refcount is a number or -, and deps is a comma-separated list
   of depends or -.
*/
3735
static const struct seq_operations modules_op = {
L
Linus Torvalds 已提交
3736 3737 3738 3739 3740 3741
	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= m_show
};

3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 3761
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
3762 3763 3764 3765 3766 3767
/* Given an address, look for it in the module exception tables. */
const struct exception_table_entry *search_module_extables(unsigned long addr)
{
	const struct exception_table_entry *e = NULL;
	struct module *mod;

R
Rusty Russell 已提交
3768
	preempt_disable();
3769
	list_for_each_entry_rcu(mod, &modules, list) {
3770 3771
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
L
Linus Torvalds 已提交
3772 3773
		if (mod->num_exentries == 0)
			continue;
D
Daniel Walker 已提交
3774

L
Linus Torvalds 已提交
3775 3776 3777 3778 3779 3780
		e = search_extable(mod->extable,
				   mod->extable + mod->num_exentries - 1,
				   addr);
		if (e)
			break;
	}
R
Rusty Russell 已提交
3781
	preempt_enable();
L
Linus Torvalds 已提交
3782 3783

	/* Now, if we found one, we are running inside it now, hence
D
Daniel Walker 已提交
3784
	   we cannot unload the module, hence no refcnt needed. */
L
Linus Torvalds 已提交
3785 3786 3787
	return e;
}

3788
/*
R
Rusty Russell 已提交
3789 3790 3791 3792 3793
 * 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).
3794
 */
R
Rusty Russell 已提交
3795
bool is_module_address(unsigned long addr)
3796
{
R
Rusty Russell 已提交
3797
	bool ret;
3798

R
Rusty Russell 已提交
3799
	preempt_disable();
R
Rusty Russell 已提交
3800
	ret = __module_address(addr) != NULL;
R
Rusty Russell 已提交
3801
	preempt_enable();
3802

R
Rusty Russell 已提交
3803
	return ret;
3804 3805
}

R
Rusty Russell 已提交
3806 3807 3808 3809 3810 3811 3812
/*
 * __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.
 */
3813
struct module *__module_address(unsigned long addr)
L
Linus Torvalds 已提交
3814 3815 3816
{
	struct module *mod;

3817 3818 3819
	if (addr < module_addr_min || addr > module_addr_max)
		return NULL;

3820 3821 3822
	list_for_each_entry_rcu(mod, &modules, list) {
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
3823
		if (within_module(addr, mod))
L
Linus Torvalds 已提交
3824
			return mod;
3825
	}
L
Linus Torvalds 已提交
3826 3827
	return NULL;
}
3828
EXPORT_SYMBOL_GPL(__module_address);
L
Linus Torvalds 已提交
3829

R
Rusty Russell 已提交
3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866
/*
 * 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;
}
3867
EXPORT_SYMBOL_GPL(__module_text_address);
R
Rusty Russell 已提交
3868

L
Linus Torvalds 已提交
3869 3870 3871 3872
/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
	struct module *mod;
3873
	char buf[8];
L
Linus Torvalds 已提交
3874

3875
	printk(KERN_DEFAULT "Modules linked in:");
3876 3877
	/* Most callers should already have preempt disabled, but make sure */
	preempt_disable();
3878 3879 3880
	list_for_each_entry_rcu(mod, &modules, list) {
		if (mod->state == MODULE_STATE_UNFORMED)
			continue;
J
Jiri Slaby 已提交
3881
		pr_cont(" %s%s", mod->name, module_flags(mod, buf));
3882
	}
3883
	preempt_enable();
3884
	if (last_unloaded_module[0])
J
Jiri Slaby 已提交
3885 3886
		pr_cont(" [last unloaded: %s]", last_unloaded_module);
	pr_cont("\n");
L
Linus Torvalds 已提交
3887 3888 3889
}

#ifdef CONFIG_MODVERSIONS
3890 3891 3892 3893 3894 3895
/* 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,
3896
		   struct tracepoint * const *tp)
3897 3898 3899
{
}
EXPORT_SYMBOL(module_layout);
L
Linus Torvalds 已提交
3900
#endif