module.c 93.5 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/stop_machine.h>
#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 <linux/fips.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 uses stop_machine/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 = {
	.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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	return blocking_notifier_chain_register(&module_notify_list, nb);
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}
EXPORT_SYMBOL(register_module_notifier);

int unregister_module_notifier(struct notifier_block * nb)
{
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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)
{
	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)
{
	add_taint(flag);
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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 (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) {
			printk(KERN_WARNING "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) {
		printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
		       "however this module is using it.\n", fsa->name);
		printk(KERN_WARNING
		       "This symbol will go away in the future.\n");
		printk(KERN_WARNING
		       "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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#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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struct module *find_module(const char *name)
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{
	struct module *mod;

	list_for_each_entry(mod, &modules, list) {
		if (strcmp(mod->name, name) == 0)
			return mod;
	}
	return NULL;
}
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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,
			   unsigned long size, unsigned long align)
{
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	if (align > PAGE_SIZE) {
		printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
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		       mod->name, align, PAGE_SIZE);
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		align = PAGE_SIZE;
	}

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	mod->percpu = __alloc_reserved_percpu(size, align);
	if (!mod->percpu) {
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		printk(KERN_WARNING
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		       "%s: Could not allocate %lu bytes percpu data\n",
		       mod->name, size);
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		return -ENOMEM;
	}
	mod->percpu_size = size;
	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) {
		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 inline int percpu_modalloc(struct module *mod,
				  unsigned long size, unsigned long align)
{
	return -ENOMEM;
}
static inline void percpu_modfree(struct module *mod)
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{
}
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static unsigned int find_pcpusec(struct load_info *info)
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{
	return 0;
}
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static inline void percpu_modcopy(struct module *mod,
				  const void *from, unsigned long size)
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{
	/* pcpusec should be 0, and size of that section should be 0. */
	BUG_ON(size != 0);
}
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bool is_module_percpu_address(unsigned long addr)
{
	return false;
}
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#endif /* CONFIG_SMP */

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

MODINFO_ATTR(version);
MODINFO_ATTR(srcversion);

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static char last_unloaded_module[MODULE_NAME_LEN+1];

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#ifdef CONFIG_MODULE_UNLOAD
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EXPORT_TRACEPOINT_SYMBOL(module_get);

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/* Init the unload section of the module. */
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static int module_unload_init(struct module *mod)
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{
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	mod->refptr = alloc_percpu(struct module_ref);
	if (!mod->refptr)
		return -ENOMEM;

619 620
	INIT_LIST_HEAD(&mod->source_list);
	INIT_LIST_HEAD(&mod->target_list);
621

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	/* Hold reference count during initialization. */
623
	__this_cpu_write(mod->refptr->incs, 1);
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	/* Backwards compatibility macros put refcount during init. */
	mod->waiter = current;
626 627

	return 0;
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}

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

635 636
	list_for_each_entry(use, &b->source_list, source_list) {
		if (use->source == a) {
637
			pr_debug("%s uses %s!\n", a->name, b->name);
L
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			return 1;
		}
	}
641
	pr_debug("%s does not use %s!\n", a->name, b->name);
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642 643 644
	return 0;
}

645 646 647 648 649 650 651 652 653 654 655
/*
 * 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;

656
	pr_debug("Allocating new usage for %s.\n", a->name);
657 658 659 660 661 662 663 664 665 666 667 668 669
	use = kmalloc(sizeof(*use), GFP_ATOMIC);
	if (!use) {
		printk(KERN_WARNING "%s: out of memory loading\n", a->name);
		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;
}

670
/* Module a uses b: caller needs module_mutex() */
671
int ref_module(struct module *a, struct module *b)
L
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672
{
673
	int err;
K
Kay Sievers 已提交
674

675
	if (b == NULL || already_uses(a, b))
676 677
		return 0;

678 679
	/* If module isn't available, we fail. */
	err = strong_try_module_get(b);
680
	if (err)
681
		return err;
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682

683 684
	err = add_module_usage(a, b);
	if (err) {
L
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685
		module_put(b);
686
		return err;
L
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687
	}
688
	return 0;
L
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689
}
690
EXPORT_SYMBOL_GPL(ref_module);
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/* Clear the unload stuff of the module. */
static void module_unload_free(struct module *mod)
{
695
	struct module_use *use, *tmp;
L
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696

697
	mutex_lock(&module_mutex);
698 699
	list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
		struct module *i = use->target;
700
		pr_debug("%s unusing %s\n", mod->name, i->name);
701 702 703 704
		module_put(i);
		list_del(&use->source_list);
		list_del(&use->target_list);
		kfree(use);
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705
	}
706
	mutex_unlock(&module_mutex);
707 708

	free_percpu(mod->refptr);
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}

#ifdef CONFIG_MODULE_FORCE_UNLOAD
712
static inline int try_force_unload(unsigned int flags)
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{
	int ret = (flags & O_TRUNC);
	if (ret)
716
		add_taint(TAINT_FORCED_RMMOD);
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	return ret;
}
#else
720
static inline int try_force_unload(unsigned int flags)
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{
	return 0;
}
#endif /* CONFIG_MODULE_FORCE_UNLOAD */

struct stopref
{
	struct module *mod;
	int flags;
	int *forced;
};

/* Whole machine is stopped with interrupts off when this runs. */
static int __try_stop_module(void *_sref)
{
	struct stopref *sref = _sref;

738 739
	/* If it's not unused, quit unless we're forcing. */
	if (module_refcount(sref->mod) != 0) {
740
		if (!(*sref->forced = try_force_unload(sref->flags)))
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			return -EWOULDBLOCK;
	}

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

static int try_stop_module(struct module *mod, int flags, int *forced)
{
751 752
	if (flags & O_NONBLOCK) {
		struct stopref sref = { mod, flags, forced };
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754
		return stop_machine(__try_stop_module, &sref, NULL);
755 756 757 758 759 760
	} else {
		/* We don't need to stop the machine for this. */
		mod->state = MODULE_STATE_GOING;
		synchronize_sched();
		return 0;
	}
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}

763
unsigned long module_refcount(struct module *mod)
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764
{
765
	unsigned long incs = 0, decs = 0;
766
	int cpu;
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768
	for_each_possible_cpu(cpu)
769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786
		decs += per_cpu_ptr(mod->refptr, cpu)->decs;
	/*
	 * ensure the incs are added up after the decs.
	 * module_put ensures incs are visible before decs with smp_wmb.
	 *
	 * This 2-count scheme avoids the situation where the refcount
	 * for CPU0 is read, then CPU0 increments the module refcount,
	 * then CPU1 drops that refcount, then the refcount for CPU1 is
	 * read. We would record a decrement but not its corresponding
	 * increment so we would see a low count (disaster).
	 *
	 * Rare situation? But module_refcount can be preempted, and we
	 * might be tallying up 4096+ CPUs. So it is not impossible.
	 */
	smp_rmb();
	for_each_possible_cpu(cpu)
		incs += per_cpu_ptr(mod->refptr, cpu)->incs;
	return incs - decs;
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}
EXPORT_SYMBOL(module_refcount);

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

static void wait_for_zero_refcount(struct module *mod)
{
795
	/* Since we might sleep for some time, release the mutex first */
796
	mutex_unlock(&module_mutex);
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797
	for (;;) {
798
		pr_debug("Looking at refcount...\n");
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		set_current_state(TASK_UNINTERRUPTIBLE);
		if (module_refcount(mod) == 0)
			break;
		schedule();
	}
	current->state = TASK_RUNNING;
805
	mutex_lock(&module_mutex);
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}

808 809
SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
		unsigned int, flags)
L
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810 811
{
	struct module *mod;
812
	char name[MODULE_NAME_LEN];
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813 814
	int ret, forced = 0;

815
	if (!capable(CAP_SYS_MODULE) || modules_disabled)
816 817 818 819 820 821
		return -EPERM;

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

822 823
	if (mutex_lock_interruptible(&module_mutex) != 0)
		return -EINTR;
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	mod = find_module(name);
	if (!mod) {
		ret = -ENOENT;
		goto out;
	}

831
	if (!list_empty(&mod->source_list)) {
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		/* Other modules depend on us: get rid of them first. */
		ret = -EWOULDBLOCK;
		goto out;
	}

	/* Doing init or already dying? */
	if (mod->state != MODULE_STATE_LIVE) {
		/* FIXME: if (force), slam module count and wake up
                   waiter --RR */
841
		pr_debug("%s already dying\n", mod->name);
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		ret = -EBUSY;
		goto out;
	}

	/* If it has an init func, it must have an exit func to unload */
847
	if (mod->init && !mod->exit) {
848
		forced = try_force_unload(flags);
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		if (!forced) {
			/* This module can't be removed */
			ret = -EBUSY;
			goto out;
		}
	}

	/* Set this up before setting mod->state */
	mod->waiter = current;

	/* Stop the machine so refcounts can't move and disable module. */
	ret = try_stop_module(mod, flags, &forced);
	if (ret != 0)
		goto out;

	/* Never wait if forced. */
	if (!forced && module_refcount(mod) != 0)
		wait_for_zero_refcount(mod);

868
	mutex_unlock(&module_mutex);
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	/* Final destruction now no one is using it. */
870
	if (mod->exit != NULL)
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		mod->exit();
872 873
	blocking_notifier_call_chain(&module_notify_list,
				     MODULE_STATE_GOING, mod);
874
	async_synchronize_full();
875

876
	/* Store the name of the last unloaded module for diagnostic purposes */
877
	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
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879 880 881
	free_module(mod);
	return 0;
out:
882
	mutex_unlock(&module_mutex);
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	return ret;
}

886
static inline void print_unload_info(struct seq_file *m, struct module *mod)
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{
	struct module_use *use;
	int printed_something = 0;

891
	seq_printf(m, " %lu ", module_refcount(mod));
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	/* Always include a trailing , so userspace can differentiate
           between this and the old multi-field proc format. */
895
	list_for_each_entry(use, &mod->source_list, source_list) {
L
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896
		printed_something = 1;
897
		seq_printf(m, "%s,", use->source->name);
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	}

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

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

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

913
	preempt_disable();
914
	if (!find_symbol(symbol, &owner, NULL, true, false))
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		BUG();
	module_put(owner);
917
	preempt_enable();
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}
EXPORT_SYMBOL(__symbol_put);

921
/* Note this assumes addr is a function, which it currently always is. */
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void symbol_put_addr(void *addr)
{
924
	struct module *modaddr;
925
	unsigned long a = (unsigned long)dereference_function_descriptor(addr);
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926

927
	if (core_kernel_text(a))
928
		return;
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929

930 931
	/* module_text_address is safe here: we're supposed to have reference
	 * to module from symbol_get, so it can't go away. */
932
	modaddr = __module_text_address(a);
933
	BUG_ON(!modaddr);
934
	module_put(modaddr);
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}
EXPORT_SYMBOL_GPL(symbol_put_addr);

static ssize_t show_refcnt(struct module_attribute *mattr,
939
			   struct module_kobject *mk, char *buffer)
L
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940
{
941
	return sprintf(buffer, "%lu\n", module_refcount(mk->mod));
L
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942 943
}

944 945
static struct module_attribute modinfo_refcnt =
	__ATTR(refcnt, 0444, show_refcnt, NULL);
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947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976
void __module_get(struct module *module)
{
	if (module) {
		preempt_disable();
		__this_cpu_inc(module->refptr->incs);
		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();

		if (likely(module_is_live(module))) {
			__this_cpu_inc(module->refptr->incs);
			trace_module_get(module, _RET_IP_);
		} else
			ret = false;

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

977 978 979
void module_put(struct module *module)
{
	if (module) {
980
		preempt_disable();
981 982
		smp_wmb(); /* see comment in module_refcount */
		__this_cpu_inc(module->refptr->decs);
983

984
		trace_module_put(module, _RET_IP_);
985 986 987
		/* Maybe they're waiting for us to drop reference? */
		if (unlikely(!module_is_live(module)))
			wake_up_process(module->waiter);
988
		preempt_enable();
989 990 991 992
	}
}
EXPORT_SYMBOL(module_put);

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993
#else /* !CONFIG_MODULE_UNLOAD */
994
static inline void print_unload_info(struct seq_file *m, struct module *mod)
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{
	/* We don't know the usage count, or what modules are using. */
	seq_printf(m, " - -");
}

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

1004
int ref_module(struct module *a, struct module *b)
L
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1005
{
1006
	return strong_try_module_get(b);
L
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1007
}
1008
EXPORT_SYMBOL_GPL(ref_module);
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1009

1010
static inline int module_unload_init(struct module *mod)
L
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1011
{
1012
	return 0;
L
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1013 1014 1015
}
#endif /* CONFIG_MODULE_UNLOAD */

1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035
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';
	/*
	 * TAINT_FORCED_RMMOD: could be added.
	 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
	 * apply to modules.
	 */
	return l;
}

1036
static ssize_t show_initstate(struct module_attribute *mattr,
1037
			      struct module_kobject *mk, char *buffer)
1038 1039 1040
{
	const char *state = "unknown";

1041
	switch (mk->mod->state) {
1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054
	case MODULE_STATE_LIVE:
		state = "live";
		break;
	case MODULE_STATE_COMING:
		state = "coming";
		break;
	case MODULE_STATE_GOING:
		state = "going";
		break;
	}
	return sprintf(buffer, "%s\n", state);
}

1055 1056
static struct module_attribute modinfo_initstate =
	__ATTR(initstate, 0444, show_initstate, NULL);
1057

1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068
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;
}

1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101
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);
1102

1103
static struct module_attribute *modinfo_attrs[] = {
1104
	&module_uevent,
1105 1106
	&modinfo_version,
	&modinfo_srcversion,
1107 1108 1109 1110
	&modinfo_initstate,
	&modinfo_coresize,
	&modinfo_initsize,
	&modinfo_taint,
1111
#ifdef CONFIG_MODULE_UNLOAD
1112
	&modinfo_refcnt,
1113 1114 1115 1116
#endif
	NULL,
};

L
Linus Torvalds 已提交
1117 1118
static const char vermagic[] = VERMAGIC_STRING;

1119
static int try_to_force_load(struct module *mod, const char *reason)
1120 1121
{
#ifdef CONFIG_MODULE_FORCE_LOAD
1122
	if (!test_taint(TAINT_FORCED_MODULE))
1123 1124
		printk(KERN_WARNING "%s: %s: kernel tainted.\n",
		       mod->name, reason);
1125 1126 1127 1128 1129 1130 1131
	add_taint_module(mod, TAINT_FORCED_MODULE);
	return 0;
#else
	return -ENOEXEC;
#endif
}

L
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1132
#ifdef CONFIG_MODVERSIONS
1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143
/* 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
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1144 1145 1146 1147
static int check_version(Elf_Shdr *sechdrs,
			 unsigned int versindex,
			 const char *symname,
			 struct module *mod, 
1148 1149
			 const unsigned long *crc,
			 const struct module *crc_owner)
L
Linus Torvalds 已提交
1150 1151 1152 1153 1154 1155 1156 1157
{
	unsigned int i, num_versions;
	struct modversion_info *versions;

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

1158 1159 1160 1161
	/* No versions at all?  modprobe --force does this. */
	if (versindex == 0)
		return try_to_force_load(mod, symname) == 0;

L
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1162 1163 1164 1165 1166 1167 1168 1169
	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;

1170
		if (versions[i].crc == maybe_relocated(*crc, crc_owner))
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1171
			return 1;
1172
		pr_debug("Found checksum %lX vs module %lX\n",
1173
		       maybe_relocated(*crc, crc_owner), versions[i].crc);
1174
		goto bad_version;
L
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1175
	}
1176

1177 1178 1179
	printk(KERN_WARNING "%s: no symbol version for %s\n",
	       mod->name, symname);
	return 0;
1180 1181 1182 1183 1184

bad_version:
	printk("%s: disagrees about version of symbol %s\n",
	       mod->name, symname);
	return 0;
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1185 1186 1187 1188 1189 1190 1191 1192
}

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

1193 1194
	/* Since this should be found in kernel (which can't be removed),
	 * no locking is necessary. */
1195 1196
	if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
			 &crc, true, false))
L
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1197
		BUG();
1198 1199
	return check_version(sechdrs, versindex, "module_layout", mod, crc,
			     NULL);
L
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1200 1201
}

1202 1203 1204
/* 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
1205
{
1206 1207 1208 1209
	if (has_crcs) {
		amagic += strcspn(amagic, " ");
		bmagic += strcspn(bmagic, " ");
	}
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	return strcmp(amagic, bmagic) == 0;
}
#else
static inline int check_version(Elf_Shdr *sechdrs,
				unsigned int versindex,
				const char *symname,
				struct module *mod, 
1217 1218
				const unsigned long *crc,
				const struct module *crc_owner)
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1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229
{
	return 1;
}

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

1230 1231
static inline int same_magic(const char *amagic, const char *bmagic,
			     bool has_crcs)
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1232 1233 1234 1235 1236
{
	return strcmp(amagic, bmagic) == 0;
}
#endif /* CONFIG_MODVERSIONS */

1237
/* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1238 1239
static const struct kernel_symbol *resolve_symbol(struct module *mod,
						  const struct load_info *info,
1240
						  const char *name,
1241
						  char ownername[])
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1242 1243
{
	struct module *owner;
1244
	const struct kernel_symbol *sym;
L
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1245
	const unsigned long *crc;
1246
	int err;
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1247

1248
	mutex_lock(&module_mutex);
1249
	sym = find_symbol(name, &owner, &crc,
1250
			  !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1251 1252 1253
	if (!sym)
		goto unlock;

1254 1255
	if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
			   owner)) {
1256 1257
		sym = ERR_PTR(-EINVAL);
		goto getname;
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1258
	}
1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269

	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:
1270
	mutex_unlock(&module_mutex);
1271
	return sym;
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1272 1273
}

1274 1275 1276 1277
static const struct kernel_symbol *
resolve_symbol_wait(struct module *mod,
		    const struct load_info *info,
		    const char *name)
1278 1279
{
	const struct kernel_symbol *ksym;
1280
	char owner[MODULE_NAME_LEN];
1281 1282

	if (wait_event_interruptible_timeout(module_wq,
1283 1284
			!IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
			|| PTR_ERR(ksym) != -EBUSY,
1285 1286
					     30 * HZ) <= 0) {
		printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
1287
		       mod->name, owner);
1288 1289 1290 1291
	}
	return ksym;
}

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1292 1293 1294 1295
/*
 * /sys/module/foo/sections stuff
 * J. Corbet <corbet@lwn.net>
 */
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#ifdef CONFIG_SYSFS
1297

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#ifdef CONFIG_KALLSYMS
1299 1300 1301 1302 1303
static inline bool sect_empty(const Elf_Shdr *sect)
{
	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
}

1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317
struct module_sect_attr
{
	struct module_attribute mattr;
	char *name;
	unsigned long address;
};

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

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static ssize_t module_sect_show(struct module_attribute *mattr,
1319
				struct module_kobject *mk, char *buf)
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{
	struct module_sect_attr *sattr =
		container_of(mattr, struct module_sect_attr, mattr);
1323
	return sprintf(buf, "0x%pK\n", (void *)sattr->address);
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1324 1325
}

1326 1327
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
1328
	unsigned int section;
1329 1330 1331 1332 1333 1334

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

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static void add_sect_attrs(struct module *mod, const struct load_info *info)
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{
	unsigned int nloaded = 0, i, size[2];
	struct module_sect_attrs *sect_attrs;
	struct module_sect_attr *sattr;
	struct attribute **gattr;
1341

L
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	/* Count loaded sections and allocate structures */
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	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]))
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1345 1346 1347 1348 1349
			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]);
1350 1351
	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
	if (sect_attrs == NULL)
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1352 1353 1354 1355 1356 1357
		return;

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

1358
	sect_attrs->nsections = 0;
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1359 1360
	sattr = &sect_attrs->attrs[0];
	gattr = &sect_attrs->grp.attrs[0];
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1361 1362 1363
	for (i = 0; i < info->hdr->e_shnum; i++) {
		Elf_Shdr *sec = &info->sechdrs[i];
		if (sect_empty(sec))
1364
			continue;
R
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1365 1366
		sattr->address = sec->sh_addr;
		sattr->name = kstrdup(info->secstrings + sec->sh_name,
1367 1368 1369 1370
					GFP_KERNEL);
		if (sattr->name == NULL)
			goto out;
		sect_attrs->nsections++;
1371
		sysfs_attr_init(&sattr->mattr.attr);
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1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385
		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:
1386
	free_sect_attrs(sect_attrs);
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1387 1388 1389 1390 1391 1392 1393 1394 1395
}

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. */
1396
		free_sect_attrs(mod->sect_attrs);
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		mod->sect_attrs = NULL;
	}
}

1401 1402 1403 1404 1405 1406 1407 1408 1409 1410
/*
 * /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];
};

1411
static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428
				 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]);
1429
		kobject_put(notes_attrs->dir);
1430 1431 1432 1433
	}
	kfree(notes_attrs);
}

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static void add_notes_attrs(struct module *mod, const struct load_info *info)
1435 1436 1437 1438 1439
{
	unsigned int notes, loaded, i;
	struct module_notes_attrs *notes_attrs;
	struct bin_attribute *nattr;

1440 1441 1442 1443
	/* failed to create section attributes, so can't create notes */
	if (!mod->sect_attrs)
		return;

1444 1445
	/* Count notes sections and allocate structures.  */
	notes = 0;
R
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1446 1447 1448
	for (i = 0; i < info->hdr->e_shnum; i++)
		if (!sect_empty(&info->sechdrs[i]) &&
		    (info->sechdrs[i].sh_type == SHT_NOTE))
1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461
			++notes;

	if (notes == 0)
		return;

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

	notes_attrs->notes = notes;
	nattr = &notes_attrs->attrs[0];
R
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1462 1463
	for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
		if (sect_empty(&info->sechdrs[i]))
1464
			continue;
R
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1465
		if (info->sechdrs[i].sh_type == SHT_NOTE) {
1466
			sysfs_bin_attr_init(nattr);
1467 1468
			nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
			nattr->attr.mode = S_IRUGO;
R
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1469 1470
			nattr->size = info->sechdrs[i].sh_size;
			nattr->private = (void *) info->sechdrs[i].sh_addr;
1471 1472 1473 1474 1475 1476
			nattr->read = module_notes_read;
			++nattr;
		}
		++loaded;
	}

1477
	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498
	if (!notes_attrs->dir)
		goto out;

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

	mod->notes_attrs = notes_attrs;
	return;

  out:
	free_notes_attrs(notes_attrs, i);
}

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

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1499
#else
1500

R
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1501 1502
static inline void add_sect_attrs(struct module *mod,
				  const struct load_info *info)
L
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1503 1504 1505 1506 1507 1508
{
}

static inline void remove_sect_attrs(struct module *mod)
{
}
1509

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1510 1511
static inline void add_notes_attrs(struct module *mod,
				   const struct load_info *info)
1512 1513 1514 1515 1516 1517
{
}

static inline void remove_notes_attrs(struct module *mod)
{
}
R
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1518
#endif /* CONFIG_KALLSYMS */
L
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1519

1520 1521 1522 1523 1524 1525
static void add_usage_links(struct module *mod)
{
#ifdef CONFIG_MODULE_UNLOAD
	struct module_use *use;
	int nowarn;

1526
	mutex_lock(&module_mutex);
1527 1528 1529 1530
	list_for_each_entry(use, &mod->target_list, target_list) {
		nowarn = sysfs_create_link(use->target->holders_dir,
					   &mod->mkobj.kobj, mod->name);
	}
1531
	mutex_unlock(&module_mutex);
1532 1533 1534 1535 1536 1537 1538 1539
#endif
}

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

1540
	mutex_lock(&module_mutex);
1541 1542
	list_for_each_entry(use, &mod->target_list, target_list)
		sysfs_remove_link(use->target->holders_dir, mod->name);
1543
	mutex_unlock(&module_mutex);
1544 1545 1546
#endif
}

1547
static int module_add_modinfo_attrs(struct module *mod)
1548 1549
{
	struct module_attribute *attr;
1550
	struct module_attribute *temp_attr;
1551 1552 1553
	int error = 0;
	int i;

1554 1555 1556 1557 1558 1559 1560
	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;
1561 1562
	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
		if (!attr->test ||
1563 1564
		    (attr->test && attr->test(mod))) {
			memcpy(temp_attr, attr, sizeof(*temp_attr));
1565
			sysfs_attr_init(&temp_attr->attr);
1566 1567 1568
			error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
			++temp_attr;
		}
1569 1570 1571 1572
	}
	return error;
}

1573
static void module_remove_modinfo_attrs(struct module *mod)
1574 1575 1576 1577
{
	struct module_attribute *attr;
	int i;

1578 1579 1580 1581
	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
		/* pick a field to test for end of list */
		if (!attr->attr.name)
			break;
1582
		sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1583 1584
		if (attr->free)
			attr->free(mod);
1585
	}
1586
	kfree(mod->modinfo_attrs);
1587
}
L
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1588

1589
static int mod_sysfs_init(struct module *mod)
L
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1590 1591
{
	int err;
1592
	struct kobject *kobj;
L
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1593

1594 1595
	if (!module_sysfs_initialized) {
		printk(KERN_ERR "%s: module sysfs not initialized\n",
1596 1597 1598 1599
		       mod->name);
		err = -EINVAL;
		goto out;
	}
1600 1601 1602 1603 1604 1605 1606 1607 1608

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

L
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1609
	mod->mkobj.mod = mod;
1610

1611 1612 1613 1614 1615 1616
	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)
		kobject_put(&mod->mkobj.kobj);
K
Kay Sievers 已提交
1617

1618
	/* delay uevent until full sysfs population */
K
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1619 1620 1621 1622
out:
	return err;
}

1623
static int mod_sysfs_setup(struct module *mod,
R
Rusty Russell 已提交
1624
			   const struct load_info *info,
K
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1625 1626 1627 1628 1629
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	int err;

1630 1631 1632 1633
	err = mod_sysfs_init(mod);
	if (err)
		goto out;

1634
	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1635 1636
	if (!mod->holders_dir) {
		err = -ENOMEM;
K
Kay Sievers 已提交
1637
		goto out_unreg;
1638
	}
K
Kay Sievers 已提交
1639

L
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1640 1641
	err = module_param_sysfs_setup(mod, kparam, num_params);
	if (err)
K
Kay Sievers 已提交
1642
		goto out_unreg_holders;
L
Linus Torvalds 已提交
1643

1644 1645
	err = module_add_modinfo_attrs(mod);
	if (err)
1646
		goto out_unreg_param;
1647

1648
	add_usage_links(mod);
R
Rusty Russell 已提交
1649 1650
	add_sect_attrs(mod, info);
	add_notes_attrs(mod, info);
1651

1652
	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
L
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1653 1654
	return 0;

1655 1656
out_unreg_param:
	module_param_sysfs_remove(mod);
K
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1657
out_unreg_holders:
1658
	kobject_put(mod->holders_dir);
K
Kay Sievers 已提交
1659
out_unreg:
1660
	kobject_put(&mod->mkobj.kobj);
1661
out:
L
Linus Torvalds 已提交
1662 1663
	return err;
}
1664 1665 1666

static void mod_sysfs_fini(struct module *mod)
{
R
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1667 1668
	remove_notes_attrs(mod);
	remove_sect_attrs(mod);
1669 1670 1671
	kobject_put(&mod->mkobj.kobj);
}

R
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1672
#else /* !CONFIG_SYSFS */
1673

R
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1674 1675
static int mod_sysfs_setup(struct module *mod,
			   const struct load_info *info,
1676 1677 1678 1679 1680 1681
			   struct kernel_param *kparam,
			   unsigned int num_params)
{
	return 0;
}

1682 1683 1684 1685
static void mod_sysfs_fini(struct module *mod)
{
}

1686 1687 1688 1689
static void module_remove_modinfo_attrs(struct module *mod)
{
}

1690 1691 1692 1693
static void del_usage_links(struct module *mod)
{
}

1694
#endif /* CONFIG_SYSFS */
L
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1695

1696
static void mod_sysfs_teardown(struct module *mod)
L
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1697
{
1698
	del_usage_links(mod);
1699
	module_remove_modinfo_attrs(mod);
L
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1700
	module_param_sysfs_remove(mod);
1701 1702
	kobject_put(mod->mkobj.drivers_dir);
	kobject_put(mod->holders_dir);
1703
	mod_sysfs_fini(mod);
L
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1704 1705 1706 1707 1708 1709 1710 1711 1712 1713
}

/*
 * unlink the module with the whole machine is stopped with interrupts off
 * - this defends against kallsyms not taking locks
 */
static int __unlink_module(void *_mod)
{
	struct module *mod = _mod;
	list_del(&mod->list);
1714
	module_bug_cleanup(mod);
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1715 1716 1717
	return 0;
}

1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761
#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);
	}
}

1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779
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);
1780 1781 1782
}

/* Iterate through all modules and set each module's text as RW */
1783
void set_all_modules_text_rw(void)
1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
		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 */
1804
void set_all_modules_text_ro(void)
1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824
{
	struct module *mod;

	mutex_lock(&module_mutex);
	list_for_each_entry_rcu(mod, &modules, list) {
		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) { }
1825 1826
static void unset_module_core_ro_nx(struct module *mod) { }
static void unset_module_init_ro_nx(struct module *mod) { }
1827 1828
#endif

1829 1830 1831 1832 1833 1834 1835 1836 1837
void __weak module_free(struct module *mod, void *module_region)
{
	vfree(module_region);
}

void __weak module_arch_cleanup(struct module *mod)
{
}

1838
/* Free a module, remove from lists, etc. */
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1839 1840
static void free_module(struct module *mod)
{
1841 1842
	trace_module_free(mod);

L
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1843
	/* Delete from various lists */
1844
	mutex_lock(&module_mutex);
1845
	stop_machine(__unlink_module, mod, NULL);
1846
	mutex_unlock(&module_mutex);
1847
	mod_sysfs_teardown(mod);
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1848

1849 1850 1851
	/* Remove dynamic debug info */
	ddebug_remove_module(mod->name);

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1852 1853 1854 1855 1856 1857
	/* Arch-specific cleanup. */
	module_arch_cleanup(mod);

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

1858 1859 1860
	/* Free any allocated parameters. */
	destroy_params(mod->kp, mod->num_kp);

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1861
	/* This may be NULL, but that's OK */
1862
	unset_module_init_ro_nx(mod);
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1863 1864
	module_free(mod, mod->module_init);
	kfree(mod->args);
1865
	percpu_modfree(mod);
1866

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1867 1868 1869
	/* Free lock-classes: */
	lockdep_free_key_range(mod->module_core, mod->core_size);

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1870
	/* Finally, free the core (containing the module structure) */
1871
	unset_module_core_ro_nx(mod);
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	module_free(mod, mod->module_core);
1873 1874 1875 1876

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

void *__symbol_get(const char *symbol)
{
	struct module *owner;
1882
	const struct kernel_symbol *sym;
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1884
	preempt_disable();
1885 1886 1887
	sym = find_symbol(symbol, &owner, NULL, true, true);
	if (sym && strong_try_module_get(owner))
		sym = NULL;
1888
	preempt_enable();
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1889

1890
	return sym ? (void *)sym->value : NULL;
L
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1891 1892 1893
}
EXPORT_SYMBOL_GPL(__symbol_get);

1894 1895
/*
 * Ensure that an exported symbol [global namespace] does not already exist
1896
 * in the kernel or in some other module's exported symbol table.
1897 1898
 *
 * You must hold the module_mutex.
1899 1900 1901
 */
static int verify_export_symbols(struct module *mod)
{
1902
	unsigned int i;
1903
	struct module *owner;
1904 1905 1906 1907 1908 1909 1910 1911
	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 },
1912
#ifdef CONFIG_UNUSED_SYMBOLS
1913 1914
		{ mod->unused_syms, mod->num_unused_syms },
		{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1915
#endif
1916
	};
1917

1918 1919
	for (i = 0; i < ARRAY_SIZE(arr); i++) {
		for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1920
			if (find_symbol(s->name, &owner, NULL, true, false)) {
1921 1922 1923 1924 1925 1926
				printk(KERN_ERR
				       "%s: exports duplicate symbol %s"
				       " (owned by %s)\n",
				       mod->name, s->name, module_name(owner));
				return -ENOEXEC;
			}
1927
		}
1928 1929
	}
	return 0;
1930 1931
}

1932
/* Change all symbols so that st_value encodes the pointer directly. */
1933 1934 1935 1936
static int simplify_symbols(struct module *mod, const struct load_info *info)
{
	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
	Elf_Sym *sym = (void *)symsec->sh_addr;
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1937
	unsigned long secbase;
1938
	unsigned int i;
L
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1939
	int ret = 0;
1940
	const struct kernel_symbol *ksym;
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1941

1942 1943 1944
	for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
		const char *name = info->strtab + sym[i].st_name;

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1945 1946 1947 1948
		switch (sym[i].st_shndx) {
		case SHN_COMMON:
			/* We compiled with -fno-common.  These are not
			   supposed to happen.  */
1949
			pr_debug("Common symbol: %s\n", name);
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1950 1951 1952 1953 1954 1955 1956
			printk("%s: please compile with -fno-common\n",
			       mod->name);
			ret = -ENOEXEC;
			break;

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

		case SHN_UNDEF:
1962
			ksym = resolve_symbol_wait(mod, info, name);
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			/* Ok if resolved.  */
1964
			if (ksym && !IS_ERR(ksym)) {
1965
				sym[i].st_value = ksym->value;
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				break;
1967 1968
			}

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1969
			/* Ok if weak.  */
1970
			if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
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				break;

1973
			printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
1974
			       mod->name, name, PTR_ERR(ksym));
1975
			ret = PTR_ERR(ksym) ?: -ENOENT;
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			break;

		default:
			/* Divert to percpu allocation if a percpu var. */
1980
			if (sym[i].st_shndx == info->index.pcpu)
1981
				secbase = (unsigned long)mod_percpu(mod);
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1982
			else
1983
				secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
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1984 1985 1986 1987 1988 1989 1990 1991
			sym[i].st_value += secbase;
			break;
		}
	}

	return ret;
}

1992
static int apply_relocations(struct module *mod, const struct load_info *info)
1993 1994 1995 1996 1997
{
	unsigned int i;
	int err = 0;

	/* Now do relocations. */
1998 1999
	for (i = 1; i < info->hdr->e_shnum; i++) {
		unsigned int infosec = info->sechdrs[i].sh_info;
2000 2001

		/* Not a valid relocation section? */
2002
		if (infosec >= info->hdr->e_shnum)
2003 2004 2005
			continue;

		/* Don't bother with non-allocated sections */
2006
		if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2007 2008
			continue;

2009 2010 2011 2012 2013 2014
		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);
2015 2016 2017 2018 2019 2020
		if (err < 0)
			break;
	}
	return err;
}

2021 2022 2023 2024 2025 2026 2027 2028
/* Additional bytes needed by arch in front of individual sections */
unsigned int __weak arch_mod_section_prepend(struct module *mod,
					     unsigned int section)
{
	/* default implementation just returns zero */
	return 0;
}

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2029
/* Update size with this section: return offset. */
2030 2031
static long get_offset(struct module *mod, unsigned int *size,
		       Elf_Shdr *sechdr, unsigned int section)
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2032 2033 2034
{
	long ret;

2035
	*size += arch_mod_section_prepend(mod, section);
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	ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
	*size = ret + sechdr->sh_size;
	return ret;
}

/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
   might -- code, read-only data, read-write data, small data.  Tally
   sizes, and place the offsets into sh_entsize fields: high bit means it
   belongs in init. */
2045
static void layout_sections(struct module *mod, struct load_info *info)
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2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057
{
	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;

2058 2059
	for (i = 0; i < info->hdr->e_shnum; i++)
		info->sechdrs[i].sh_entsize = ~0UL;
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2060

2061
	pr_debug("Core section allocation order:\n");
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2062
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2063 2064 2065
		for (i = 0; i < info->hdr->e_shnum; ++i) {
			Elf_Shdr *s = &info->sechdrs[i];
			const char *sname = info->secstrings + s->sh_name;
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2066 2067 2068 2069

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2070
			    || strstarts(sname, ".init"))
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2071
				continue;
2072
			s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2073
			pr_debug("\t%s\n", sname);
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2074
		}
2075 2076 2077
		switch (m) {
		case 0: /* executable */
			mod->core_size = debug_align(mod->core_size);
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2078
			mod->core_text_size = mod->core_size;
2079 2080 2081 2082 2083 2084 2085 2086 2087
			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
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2088 2089
	}

2090
	pr_debug("Init section allocation order:\n");
L
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2091
	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2092 2093 2094
		for (i = 0; i < info->hdr->e_shnum; ++i) {
			Elf_Shdr *s = &info->sechdrs[i];
			const char *sname = info->secstrings + s->sh_name;
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2095 2096 2097 2098

			if ((s->sh_flags & masks[m][0]) != masks[m][0]
			    || (s->sh_flags & masks[m][1])
			    || s->sh_entsize != ~0UL
2099
			    || !strstarts(sname, ".init"))
L
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2100
				continue;
2101
			s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
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2102
					 | INIT_OFFSET_MASK);
2103
			pr_debug("\t%s\n", sname);
L
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2104
		}
2105 2106 2107
		switch (m) {
		case 0: /* executable */
			mod->init_size = debug_align(mod->init_size);
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2108
			mod->init_text_size = mod->init_size;
2109 2110 2111 2112 2113 2114 2115 2116 2117
			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;
		}
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2118 2119 2120 2121 2122 2123 2124 2125
	}
}

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

2126
	if (!license_is_gpl_compatible(license)) {
2127
		if (!test_taint(TAINT_PROPRIETARY_MODULE))
2128
			printk(KERN_WARNING "%s: module license '%s' taints "
2129 2130
				"kernel.\n", mod->name, license);
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
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2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152
	}
}

/* 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;
}

2153
static char *get_modinfo(struct load_info *info, const char *tag)
L
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2154 2155 2156
{
	char *p;
	unsigned int taglen = strlen(tag);
2157 2158
	Elf_Shdr *infosec = &info->sechdrs[info->index.info];
	unsigned long size = infosec->sh_size;
L
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2159

2160
	for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
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2161 2162 2163 2164 2165 2166
		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
			return p + taglen + 1;
	}
	return NULL;
}

2167
static void setup_modinfo(struct module *mod, struct load_info *info)
2168 2169 2170 2171 2172 2173
{
	struct module_attribute *attr;
	int i;

	for (i = 0; (attr = modinfo_attrs[i]); i++) {
		if (attr->setup)
2174
			attr->setup(mod, get_modinfo(info, attr->attr.name));
2175 2176 2177
	}
}

2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188
static void free_modinfo(struct module *mod)
{
	struct module_attribute *attr;
	int i;

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

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2189
#ifdef CONFIG_KALLSYMS
2190 2191 2192 2193 2194 2195

/* 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)
{
2196 2197
	return bsearch(name, start, stop - start,
			sizeof(struct kernel_symbol), cmp_name);
2198 2199
}

2200 2201
static int is_exported(const char *name, unsigned long value,
		       const struct module *mod)
L
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2202
{
2203 2204 2205
	const struct kernel_symbol *ks;
	if (!mod)
		ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2206
	else
2207 2208
		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
	return ks != NULL && ks->value == value;
L
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2209 2210 2211
}

/* As per nm */
2212
static char elf_type(const Elf_Sym *sym, const struct load_info *info)
L
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2213
{
2214 2215
	const Elf_Shdr *sechdrs = info->sechdrs;

L
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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 2244
	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';
	}
2245 2246
	if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
		      ".debug")) {
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2247
		return 'n';
2248
	}
L
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2249 2250 2251
	return '?';
}

2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272
static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
                           unsigned int shnum)
{
	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;
}

2273 2274 2275 2276 2277 2278 2279
/*
 * 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>.
 */
2280
static void layout_symtab(struct module *mod, struct load_info *info)
2281
{
2282 2283
	Elf_Shdr *symsect = info->sechdrs + info->index.sym;
	Elf_Shdr *strsect = info->sechdrs + info->index.str;
2284
	const Elf_Sym *src;
2285
	unsigned int i, nsrc, ndst, strtab_size = 0;
2286 2287 2288 2289

	/* 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,
2290
					 info->index.sym) | INIT_OFFSET_MASK;
2291
	pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2292

2293
	src = (void *)info->hdr + symsect->sh_offset;
2294
	nsrc = symsect->sh_size / sizeof(*src);
2295

2296
	/* Compute total space required for the core symbols' strtab. */
2297 2298 2299 2300
	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;
2301
			ndst++;
2302
		}
2303
	}
2304 2305

	/* Append room for core symbols at end of core part. */
2306
	info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2307 2308
	info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
	mod->core_size += strtab_size;
2309

2310 2311 2312
	/* 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,
2313
					 info->index.str) | INIT_OFFSET_MASK;
2314
	pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2315 2316
}

2317
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2318
{
2319 2320 2321
	unsigned int i, ndst;
	const Elf_Sym *src;
	Elf_Sym *dst;
2322
	char *s;
2323
	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
L
Linus Torvalds 已提交
2324

2325 2326
	mod->symtab = (void *)symsec->sh_addr;
	mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2327 2328
	/* 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
2329 2330 2331

	/* Set types up while we still have access to sections. */
	for (i = 0; i < mod->num_symtab; i++)
2332
		mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2333

2334
	mod->core_symtab = dst = mod->module_core + info->symoffs;
2335
	mod->core_strtab = s = mod->module_core + info->stroffs;
2336
	src = mod->symtab;
2337 2338 2339 2340 2341 2342 2343 2344
	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;
		}
2345 2346
	}
	mod->core_num_syms = ndst;
L
Linus Torvalds 已提交
2347 2348
}
#else
2349
static inline void layout_symtab(struct module *mod, struct load_info *info)
2350 2351
{
}
2352

2353
static void add_kallsyms(struct module *mod, const struct load_info *info)
L
Linus Torvalds 已提交
2354 2355 2356 2357
{
}
#endif /* CONFIG_KALLSYMS */

2358
static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2359
{
2360 2361
	if (!debug)
		return;
2362 2363 2364 2365 2366
#ifdef CONFIG_DYNAMIC_DEBUG
	if (ddebug_add_module(debug, num, debug->modname))
		printk(KERN_ERR "dynamic debug error adding module: %s\n",
					debug->modname);
#endif
2367
}
2368

2369 2370 2371 2372 2373 2374
static void dynamic_debug_remove(struct _ddebug *debug)
{
	if (debug)
		ddebug_remove_module(debug->modname);
}

2375 2376
void * __weak module_alloc(unsigned long size)
{
2377
	return vmalloc_exec(size);
2378 2379
}

2380 2381 2382 2383 2384
static void *module_alloc_update_bounds(unsigned long size)
{
	void *ret = module_alloc(size);

	if (ret) {
2385
		mutex_lock(&module_mutex);
2386 2387 2388 2389 2390
		/* 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;
2391
		mutex_unlock(&module_mutex);
2392 2393 2394 2395
	}
	return ret;
}

2396
#ifdef CONFIG_DEBUG_KMEMLEAK
2397 2398
static void kmemleak_load_module(const struct module *mod,
				 const struct load_info *info)
2399 2400 2401 2402
{
	unsigned int i;

	/* only scan the sections containing data */
2403
	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2404

2405 2406 2407
	for (i = 1; i < info->hdr->e_shnum; i++) {
		const char *name = info->secstrings + info->sechdrs[i].sh_name;
		if (!(info->sechdrs[i].sh_flags & SHF_ALLOC))
2408
			continue;
2409
		if (!strstarts(name, ".data") && !strstarts(name, ".bss"))
2410 2411
			continue;

2412 2413
		kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
				   info->sechdrs[i].sh_size, GFP_KERNEL);
2414 2415 2416
	}
}
#else
2417 2418
static inline void kmemleak_load_module(const struct module *mod,
					const struct load_info *info)
2419 2420 2421 2422
{
}
#endif

2423
#ifdef CONFIG_MODULE_SIG
2424
static int module_sig_check(struct load_info *info)
2425 2426
{
	int err = -ENOKEY;
2427 2428
	const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
	const void *mod = info->hdr;
2429

2430 2431
	if (info->len > markerlen &&
	    memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2432
		/* We truncate the module to discard the signature */
2433 2434
		info->len -= markerlen;
		err = mod_verify_sig(mod, &info->len);
2435 2436 2437 2438 2439 2440 2441 2442
	}

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

	/* Not having a signature is only an error if we're strict. */
D
David Howells 已提交
2443 2444 2445
	if (err < 0 && fips_enabled)
		panic("Module verification failed with error %d in FIPS mode\n",
		      err);
2446 2447 2448 2449 2450 2451
	if (err == -ENOKEY && !sig_enforce)
		err = 0;

	return err;
}
#else /* !CONFIG_MODULE_SIG */
2452
static int module_sig_check(struct load_info *info)
2453 2454 2455 2456 2457
{
	return 0;
}
#endif /* !CONFIG_MODULE_SIG */

2458 2459
/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
static int elf_header_check(struct load_info *info)
2460
{
2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473
	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;
2474

2475 2476 2477 2478 2479 2480
	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)
2481 2482 2483
{
	int err;

2484 2485
	info->len = len;
	if (info->len < sizeof(*(info->hdr)))
2486 2487
		return -ENOEXEC;

2488 2489 2490 2491
	err = security_kernel_module_from_file(NULL);
	if (err)
		return err;

2492
	/* Suck in entire file: we'll want most of it. */
2493 2494
	info->hdr = vmalloc(info->len);
	if (!info->hdr)
2495 2496
		return -ENOMEM;

2497 2498 2499
	if (copy_from_user(info->hdr, umod, info->len) != 0) {
		vfree(info->hdr);
		return -EFAULT;
2500 2501
	}

2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517
	return 0;
}

/* Sets info->hdr and info->len. */
static int copy_module_from_fd(int fd, struct load_info *info)
{
	struct file *file;
	int err;
	struct kstat stat;
	loff_t pos;
	ssize_t bytes = 0;

	file = fget(fd);
	if (!file)
		return -ENOEXEC;

2518
	err = security_kernel_module_from_file(file);
2519
	if (err)
2520
		goto out;
2521

2522
	err = vfs_getattr(file->f_vfsmnt, file->f_dentry, &stat);
2523
	if (err)
2524
		goto out;
2525

2526 2527 2528
	if (stat.size > INT_MAX) {
		err = -EFBIG;
		goto out;
2529
	}
2530 2531 2532 2533
	info->hdr = vmalloc(stat.size);
	if (!info->hdr) {
		err = -ENOMEM;
		goto out;
2534
	}
2535

2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549
	pos = 0;
	while (pos < stat.size) {
		bytes = kernel_read(file, pos, (char *)(info->hdr) + pos,
				    stat.size - pos);
		if (bytes < 0) {
			vfree(info->hdr);
			err = bytes;
			goto out;
		}
		if (bytes == 0)
			break;
		pos += bytes;
	}
	info->len = pos;
2550

2551 2552
out:
	fput(file);
2553 2554 2555
	return err;
}

2556 2557 2558 2559 2560
static void free_copy(struct load_info *info)
{
	vfree(info->hdr);
}

2561
static int rewrite_section_headers(struct load_info *info, int flags)
2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586
{
	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) {
			printk(KERN_ERR "Module len %lu truncated\n",
			       info->len);
			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
	}
2587 2588

	/* Track but don't keep modinfo and version sections. */
2589 2590 2591 2592
	if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
		info->index.vers = 0; /* Pretend no __versions section! */
	else
		info->index.vers = find_sec(info, "__versions");
2593
	info->index.info = find_sec(info, ".modinfo");
2594 2595
	info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
	info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2596 2597 2598
	return 0;
}

L
Linus Torvalds 已提交
2599 2600 2601 2602 2603 2604 2605 2606
/*
 * 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).
 */
2607
static struct module *setup_load_info(struct load_info *info, int flags)
L
Linus Torvalds 已提交
2608 2609
{
	unsigned int i;
2610
	int err;
L
Linus Torvalds 已提交
2611 2612 2613 2614
	struct module *mod;

	/* Set up the convenience variables */
	info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2615 2616
	info->secstrings = (void *)info->hdr
		+ info->sechdrs[info->hdr->e_shstrndx].sh_offset;
L
Linus Torvalds 已提交
2617

2618
	err = rewrite_section_headers(info, flags);
2619 2620
	if (err)
		return ERR_PTR(err);
L
Linus Torvalds 已提交
2621

2622 2623
	/* Find internal symbols and strings. */
	for (i = 1; i < info->hdr->e_shnum; i++) {
L
Linus Torvalds 已提交
2624 2625 2626
		if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
			info->index.sym = i;
			info->index.str = info->sechdrs[i].sh_link;
2627 2628 2629
			info->strtab = (char *)info->hdr
				+ info->sechdrs[info->index.str].sh_offset;
			break;
L
Linus Torvalds 已提交
2630 2631 2632
		}
	}

2633
	info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
L
Linus Torvalds 已提交
2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646
	if (!info->index.mod) {
		printk(KERN_WARNING "No module found in object\n");
		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) {
		printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
		       mod->name);
		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)) {
2670 2671 2672 2673 2674
		printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
		       mod->name, modmagic, vermagic);
		return -ENOEXEC;
	}

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

2678
	if (get_modinfo(info, "staging")) {
2679 2680 2681 2682 2683
		add_taint_module(mod, TAINT_CRAP);
		printk(KERN_WARNING "%s: module is from the staging directory,"
		       " the quality is unknown, you have been warned.\n",
		       mod->name);
	}
2684 2685

	/* Set up license info based on the info section */
2686
	set_license(mod, get_modinfo(info, "license"));
2687

2688 2689 2690
	return 0;
}

2691
static void find_module_sections(struct module *mod, struct load_info *info)
2692
{
2693
	mod->kp = section_objs(info, "__param",
2694
			       sizeof(*mod->kp), &mod->num_kp);
2695
	mod->syms = section_objs(info, "__ksymtab",
2696
				 sizeof(*mod->syms), &mod->num_syms);
2697 2698
	mod->crcs = section_addr(info, "__kcrctab");
	mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2699 2700
				     sizeof(*mod->gpl_syms),
				     &mod->num_gpl_syms);
2701 2702
	mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
	mod->gpl_future_syms = section_objs(info,
2703 2704 2705
					    "__ksymtab_gpl_future",
					    sizeof(*mod->gpl_future_syms),
					    &mod->num_gpl_future_syms);
2706
	mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2707 2708

#ifdef CONFIG_UNUSED_SYMBOLS
2709
	mod->unused_syms = section_objs(info, "__ksymtab_unused",
2710 2711
					sizeof(*mod->unused_syms),
					&mod->num_unused_syms);
2712 2713
	mod->unused_crcs = section_addr(info, "__kcrctab_unused");
	mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2714 2715
					    sizeof(*mod->unused_gpl_syms),
					    &mod->num_unused_gpl_syms);
2716
	mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2717 2718
#endif
#ifdef CONFIG_CONSTRUCTORS
2719
	mod->ctors = section_objs(info, ".ctors",
2720 2721 2722 2723
				  sizeof(*mod->ctors), &mod->num_ctors);
#endif

#ifdef CONFIG_TRACEPOINTS
2724 2725 2726
	mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
					     sizeof(*mod->tracepoints_ptrs),
					     &mod->num_tracepoints);
2727
#endif
2728 2729 2730 2731 2732
#ifdef HAVE_JUMP_LABEL
	mod->jump_entries = section_objs(info, "__jump_table",
					sizeof(*mod->jump_entries),
					&mod->num_jump_entries);
#endif
2733
#ifdef CONFIG_EVENT_TRACING
2734
	mod->trace_events = section_objs(info, "_ftrace_events",
2735 2736 2737 2738 2739 2740 2741 2742 2743
					 sizeof(*mod->trace_events),
					 &mod->num_trace_events);
	/*
	 * This section contains pointers to allocated objects in the trace
	 * code and not scanning it leads to false positives.
	 */
	kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
			   mod->num_trace_events, GFP_KERNEL);
#endif
2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755
#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);
	/*
	 * This section contains pointers to allocated objects in the trace
	 * code and not scanning it leads to false positives.
	 */
	kmemleak_scan_area(mod->trace_bprintk_fmt_start,
			   sizeof(*mod->trace_bprintk_fmt_start) *
			   mod->num_trace_bprintk_fmt, GFP_KERNEL);
#endif
2756 2757
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
	/* sechdrs[0].sh_size is always zero */
2758
	mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2759 2760 2761
					     sizeof(*mod->ftrace_callsites),
					     &mod->num_ftrace_callsites);
#endif
2762

2763 2764 2765
	mod->extable = section_objs(info, "__ex_table",
				    sizeof(*mod->extable), &mod->num_exentries);

2766
	if (section_addr(info, "__obsparm"))
2767 2768
		printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
		       mod->name);
2769 2770 2771

	info->debug = section_objs(info, "__verbose",
				   sizeof(*info->debug), &info->num_debug);
2772 2773
}

2774
static int move_module(struct module *mod, struct load_info *info)
2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787
{
	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)
2788
		return -ENOMEM;
2789 2790 2791 2792

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

2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809
	if (mod->init_size) {
		ptr = module_alloc_update_bounds(mod->init_size);
		/*
		 * The pointer to this block is stored in the module structure
		 * which is inside the block. This block doesn't need to be
		 * scanned as it contains data and code that will be freed
		 * after the module is initialized.
		 */
		kmemleak_ignore(ptr);
		if (!ptr) {
			module_free(mod, mod->module_core);
			return -ENOMEM;
		}
		memset(ptr, 0, mod->init_size);
		mod->module_init = ptr;
	} else
		mod->module_init = NULL;
2810 2811

	/* Transfer each section which specifies SHF_ALLOC */
2812
	pr_debug("final section addresses:\n");
2813
	for (i = 0; i < info->hdr->e_shnum; i++) {
2814
		void *dest;
2815
		Elf_Shdr *shdr = &info->sechdrs[i];
2816

2817
		if (!(shdr->sh_flags & SHF_ALLOC))
2818 2819
			continue;

2820
		if (shdr->sh_entsize & INIT_OFFSET_MASK)
2821
			dest = mod->module_init
2822
				+ (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2823
		else
2824
			dest = mod->module_core + shdr->sh_entsize;
2825

2826 2827
		if (shdr->sh_type != SHT_NOBITS)
			memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2828
		/* Update sh_addr to point to copy in image. */
2829
		shdr->sh_addr = (unsigned long)dest;
2830 2831
		pr_debug("\t0x%lx %s\n",
			 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2832
	}
2833 2834

	return 0;
2835 2836
}

2837
static int check_module_license_and_versions(struct module *mod)
2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850
{
	/*
	 * 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)
		add_taint(TAINT_PROPRIETARY_MODULE);

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

2851 2852 2853 2854
	/* lve claims to be GPL but upstream won't provide source */
	if (strcmp(mod->name, "lve") == 0)
		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);

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
#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);
}

2894 2895 2896 2897 2898 2899 2900 2901
int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
				     Elf_Shdr *sechdrs,
				     char *secstrings,
				     struct module *mod)
{
	return 0;
}

2902
static struct module *layout_and_allocate(struct load_info *info, int flags)
L
Linus Torvalds 已提交
2903
{
2904
	/* Module within temporary copy. */
L
Linus Torvalds 已提交
2905
	struct module *mod;
2906
	Elf_Shdr *pcpusec;
2907
	int err;
2908

2909
	mod = setup_load_info(info, flags);
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
		goto out;
L
Linus Torvalds 已提交
2922

2923 2924
	pcpusec = &info->sechdrs[info->index.pcpu];
	if (pcpusec->sh_size) {
L
Linus Torvalds 已提交
2925
		/* We have a special allocation for this section. */
2926 2927
		err = percpu_modalloc(mod,
				      pcpusec->sh_size, pcpusec->sh_addralign);
2928
		if (err)
2929
			goto out;
2930
		pcpusec->sh_flags &= ~(unsigned long)SHF_ALLOC;
L
Linus Torvalds 已提交
2931 2932 2933 2934 2935
	}

	/* 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. */
2936 2937
	layout_sections(mod, info);
	layout_symtab(mod, info);
L
Linus Torvalds 已提交
2938

2939
	/* Allocate and move to the final place */
2940
	err = move_module(mod, info);
2941
	if (err)
2942
		goto free_percpu;
2943 2944 2945

	/* Module has been copied to its final place now: return it. */
	mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2946
	kmemleak_load_module(mod, info);
2947 2948 2949 2950
	return mod;

free_percpu:
	percpu_modfree(mod);
2951
out:
2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962
	return ERR_PTR(err);
}

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

2963 2964 2965 2966 2967 2968 2969
int __weak module_finalize(const Elf_Ehdr *hdr,
			   const Elf_Shdr *sechdrs,
			   struct module *me)
{
	return 0;
}

2970 2971
static int post_relocation(struct module *mod, const struct load_info *info)
{
2972
	/* Sort exception table now relocations are done. */
2973 2974 2975 2976 2977 2978
	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);

2979
	/* Setup kallsyms-specific fields. */
2980 2981 2982 2983 2984 2985
	add_kallsyms(mod, info);

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

2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999
/* 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);
	mod = find_module(name);
	ret = !mod || mod->state != MODULE_STATE_COMING;
	mutex_unlock(&module_mutex);

	return ret;
}

3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092
/* Call module constructors. */
static void do_mod_ctors(struct module *mod)
{
#ifdef CONFIG_CONSTRUCTORS
	unsigned long i;

	for (i = 0; i < mod->num_ctors; i++)
		mod->ctors[i]();
#endif
}

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

	blocking_notifier_call_chain(&module_notify_list,
			MODULE_STATE_COMING, mod);

	/* 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);

	do_mod_ctors(mod);
	/* Start the module */
	if (mod->init != NULL)
		ret = do_one_initcall(mod->init);
	if (ret < 0) {
		/* Init routine failed: abort.  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;
	}
	if (ret > 0) {
		printk(KERN_WARNING
"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
"%s: loading module anyway...\n",
		       __func__, mod->name, ret,
		       __func__);
		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);

	/* We need to finish all async code before the module init sequence is done */
	async_synchronize_full();

	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);
	module_free(mod, mod->module_init);
	mod->module_init = NULL;
	mod->init_size = 0;
	mod->init_ro_size = 0;
	mod->init_text_size = 0;
	mutex_unlock(&module_mutex);
	wake_up_all(&module_wq);

	return 0;
}

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

	return 0;
}

3093 3094
/* Allocate and load the module: note that size of section 0 is always
   zero, and we rely on this for optional sections. */
3095 3096
static int load_module(struct load_info *info, const char __user *uargs,
		       int flags)
3097
{
3098
	struct module *mod, *old;
3099 3100
	long err;

3101 3102 3103
	err = module_sig_check(info);
	if (err)
		goto free_copy;
3104

3105
	err = elf_header_check(info);
3106
	if (err)
3107
		goto free_copy;
3108 3109

	/* Figure out module layout, and allocate all the memory. */
3110
	mod = layout_and_allocate(info, flags);
3111 3112
	if (IS_ERR(mod)) {
		err = PTR_ERR(mod);
3113
		goto free_copy;
L
Linus Torvalds 已提交
3114 3115
	}

3116
#ifdef CONFIG_MODULE_SIG
3117
	mod->sig_ok = info->sig_ok;
3118 3119 3120 3121
	if (!mod->sig_ok)
		add_taint_module(mod, TAINT_FORCED_MODULE);
#endif

3122
	/* Now module is in final location, initialize linked lists, etc. */
3123 3124
	err = module_unload_init(mod);
	if (err)
3125
		goto free_module;
L
Linus Torvalds 已提交
3126

3127 3128
	/* Now we've got everything in the final locations, we can
	 * find optional sections. */
3129
	find_module_sections(mod, info);
3130

3131
	err = check_module_license_and_versions(mod);
3132 3133
	if (err)
		goto free_unload;
3134

3135
	/* Set up MODINFO_ATTR fields */
3136
	setup_modinfo(mod, info);
3137

L
Linus Torvalds 已提交
3138
	/* Fix up syms, so that st_value is a pointer to location. */
3139
	err = simplify_symbols(mod, info);
L
Linus Torvalds 已提交
3140
	if (err < 0)
3141
		goto free_modinfo;
L
Linus Torvalds 已提交
3142

3143
	err = apply_relocations(mod, info);
3144
	if (err < 0)
3145
		goto free_modinfo;
L
Linus Torvalds 已提交
3146

3147
	err = post_relocation(mod, info);
L
Linus Torvalds 已提交
3148
	if (err < 0)
3149
		goto free_modinfo;
L
Linus Torvalds 已提交
3150

3151
	flush_module_icache(mod);
3152

3153 3154 3155 3156 3157 3158
	/* 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;
	}
3159

3160
	/* Mark state as coming so strong_try_module_get() ignores us. */
3161 3162
	mod->state = MODULE_STATE_COMING;

3163
	/* Now sew it into the lists so we can get lockdep and oops
L
Lucas De Marchi 已提交
3164
	 * info during argument parsing.  No one should access us, since
3165 3166 3167 3168 3169
	 * strong_try_module_get() will fail.
	 * lockdep/oops can run asynchronous, so use the RCU list insertion
	 * function to insert in a way safe to concurrent readers.
	 * The mutex protects against concurrent writers.
	 */
3170
again:
3171
	mutex_lock(&module_mutex);
3172 3173 3174 3175 3176 3177 3178 3179 3180 3181
	if ((old = find_module(mod->name)) != NULL) {
		if (old->state == MODULE_STATE_COMING) {
			/* Wait in case it fails to load. */
			mutex_unlock(&module_mutex);
			err = wait_event_interruptible(module_wq,
					       finished_loading(mod->name));
			if (err)
				goto free_arch_cleanup;
			goto again;
		}
3182
		err = -EEXIST;
3183
		goto unlock;
3184 3185
	}

3186
	/* This has to be done once we're sure module name is unique. */
3187
	dynamic_debug_setup(info->debug, info->num_debug);
3188

3189 3190 3191
	/* Find duplicate symbols */
	err = verify_export_symbols(mod);
	if (err < 0)
3192
		goto ddebug;
3193

3194
	module_bug_finalize(info->hdr, info->sechdrs, mod);
3195
	list_add_rcu(&mod->list, &modules);
3196
	mutex_unlock(&module_mutex);
3197

3198
	/* Module is ready to execute: parsing args may do that. */
3199
	err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3200
			 -32768, 32767, &ddebug_dyndbg_module_param_cb);
L
Linus Torvalds 已提交
3201
	if (err < 0)
3202
		goto unlink;
L
Linus Torvalds 已提交
3203

3204
	/* Link in to syfs. */
3205
	err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
L
Linus Torvalds 已提交
3206
	if (err < 0)
3207
		goto unlink;
3208

3209
	/* Get rid of temporary copy. */
3210
	free_copy(info);
L
Linus Torvalds 已提交
3211 3212

	/* Done! */
3213
	trace_module_load(mod);
3214 3215

	return do_init_module(mod);
L
Linus Torvalds 已提交
3216

3217
 unlink:
3218
	mutex_lock(&module_mutex);
3219 3220
	/* Unlink carefully: kallsyms could be walking list. */
	list_del_rcu(&mod->list);
3221
	module_bug_cleanup(mod);
3222
	wake_up_all(&module_wq);
3223
 ddebug:
3224
	dynamic_debug_remove(info->debug);
3225
 unlock:
3226
	mutex_unlock(&module_mutex);
3227
	synchronize_sched();
3228 3229
	kfree(mod->args);
 free_arch_cleanup:
L
Linus Torvalds 已提交
3230
	module_arch_cleanup(mod);
3231
 free_modinfo:
3232
	free_modinfo(mod);
3233
 free_unload:
L
Linus Torvalds 已提交
3234
	module_unload_free(mod);
3235
 free_module:
3236
	module_deallocate(mod, info);
3237
 free_copy:
3238 3239
	free_copy(info);
	return err;
3240 3241
}

3242 3243
SYSCALL_DEFINE3(init_module, void __user *, umod,
		unsigned long, len, const char __user *, uargs)
L
Linus Torvalds 已提交
3244
{
3245 3246
	int err;
	struct load_info info = { };
L
Linus Torvalds 已提交
3247

3248 3249 3250
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3251

3252 3253
	pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
	       umod, len, uargs);
L
Linus Torvalds 已提交
3254

3255 3256 3257
	err = copy_module_from_user(umod, len, &info);
	if (err)
		return err;
L
Linus Torvalds 已提交
3258

3259
	return load_module(&info, uargs, 0);
3260
}
3261

3262
SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3263 3264 3265
{
	int err;
	struct load_info info = { };
3266

3267 3268 3269
	err = may_init_module();
	if (err)
		return err;
L
Linus Torvalds 已提交
3270

3271
	pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3272

3273 3274 3275
	if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
		      |MODULE_INIT_IGNORE_VERMAGIC))
		return -EINVAL;
3276

3277 3278 3279
	err = copy_module_from_fd(fd, &info);
	if (err)
		return err;
L
Linus Torvalds 已提交
3280

3281
	return load_module(&info, uargs, flags);
L
Linus Torvalds 已提交
3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295
}

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 $d.
 */
static inline int is_arm_mapping_symbol(const char *str)
{
3296
	return str[0] == '$' && strchr("atd", str[1])
L
Linus Torvalds 已提交
3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308
	       && (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 */
3309
	if (within_module_init(addr, mod))
L
Linus Torvalds 已提交
3310
		nextval = (unsigned long)mod->module_init+mod->init_text_size;
3311
	else
L
Linus Torvalds 已提交
3312 3313
		nextval = (unsigned long)mod->module_core+mod->core_text_size;

L
Lucas De Marchi 已提交
3314
	/* Scan for closest preceding symbol, and next symbol. (ELF
3315
	   starts real symbols at 1). */
L
Linus Torvalds 已提交
3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336
	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;

3337 3338 3339 3340
	if (size)
		*size = nextval - mod->symtab[best].st_value;
	if (offset)
		*offset = addr - mod->symtab[best].st_value;
L
Linus Torvalds 已提交
3341 3342 3343
	return mod->strtab + mod->symtab[best].st_name;
}

3344 3345
/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3346
const char *module_address_lookup(unsigned long addr,
3347 3348 3349 3350
			    unsigned long *size,
			    unsigned long *offset,
			    char **modname,
			    char *namebuf)
L
Linus Torvalds 已提交
3351 3352
{
	struct module *mod;
3353
	const char *ret = NULL;
L
Linus Torvalds 已提交
3354

3355
	preempt_disable();
3356
	list_for_each_entry_rcu(mod, &modules, list) {
3357 3358
		if (within_module_init(addr, mod) ||
		    within_module_core(addr, mod)) {
3359 3360
			if (modname)
				*modname = mod->name;
3361 3362
			ret = get_ksymbol(mod, addr, size, offset);
			break;
L
Linus Torvalds 已提交
3363 3364
		}
	}
3365 3366 3367 3368 3369
	/* Make a copy in here where it's safe */
	if (ret) {
		strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
		ret = namebuf;
	}
3370
	preempt_enable();
3371
	return ret;
L
Linus Torvalds 已提交
3372 3373
}

3374 3375 3376 3377
int lookup_module_symbol_name(unsigned long addr, char *symname)
{
	struct module *mod;

3378
	preempt_disable();
3379
	list_for_each_entry_rcu(mod, &modules, list) {
3380 3381
		if (within_module_init(addr, mod) ||
		    within_module_core(addr, mod)) {
3382 3383 3384 3385 3386
			const char *sym;

			sym = get_ksymbol(mod, addr, NULL, NULL);
			if (!sym)
				goto out;
3387
			strlcpy(symname, sym, KSYM_NAME_LEN);
3388
			preempt_enable();
3389 3390 3391 3392
			return 0;
		}
	}
out:
3393
	preempt_enable();
3394 3395 3396
	return -ERANGE;
}

3397 3398 3399 3400 3401
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
			unsigned long *offset, char *modname, char *name)
{
	struct module *mod;

3402
	preempt_disable();
3403
	list_for_each_entry_rcu(mod, &modules, list) {
3404 3405
		if (within_module_init(addr, mod) ||
		    within_module_core(addr, mod)) {
3406 3407 3408 3409 3410 3411
			const char *sym;

			sym = get_ksymbol(mod, addr, size, offset);
			if (!sym)
				goto out;
			if (modname)
3412
				strlcpy(modname, mod->name, MODULE_NAME_LEN);
3413
			if (name)
3414
				strlcpy(name, sym, KSYM_NAME_LEN);
3415
			preempt_enable();
3416 3417 3418 3419
			return 0;
		}
	}
out:
3420
	preempt_enable();
3421 3422 3423
	return -ERANGE;
}

3424 3425
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
3426 3427 3428
{
	struct module *mod;

3429
	preempt_disable();
3430
	list_for_each_entry_rcu(mod, &modules, list) {
L
Linus Torvalds 已提交
3431 3432 3433
		if (symnum < mod->num_symtab) {
			*value = mod->symtab[symnum].st_value;
			*type = mod->symtab[symnum].st_info;
3434
			strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3435 3436
				KSYM_NAME_LEN);
			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3437
			*exported = is_exported(name, *value, mod);
3438
			preempt_enable();
3439
			return 0;
L
Linus Torvalds 已提交
3440 3441 3442
		}
		symnum -= mod->num_symtab;
	}
3443
	preempt_enable();
3444
	return -ERANGE;
L
Linus Torvalds 已提交
3445 3446 3447 3448 3449 3450 3451
}

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

	for (i = 0; i < mod->num_symtab; i++)
3452 3453
		if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
		    mod->symtab[i].st_info != 'U')
L
Linus Torvalds 已提交
3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465
			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. */
3466
	preempt_disable();
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	if ((colon = strchr(name, ':')) != NULL) {
		*colon = '\0';
		if ((mod = find_module(name)) != NULL)
			ret = mod_find_symname(mod, colon+1);
		*colon = ':';
	} else {
3473
		list_for_each_entry_rcu(mod, &modules, list)
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			if ((ret = mod_find_symname(mod, name)) != 0)
				break;
	}
3477
	preempt_enable();
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3478 3479
	return ret;
}
3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498

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) {
		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;
}
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#endif /* CONFIG_KALLSYMS */

3501
static char *module_flags(struct module *mod, char *buf)
3502 3503 3504
{
	int bx = 0;

3505 3506 3507
	if (mod->taints ||
	    mod->state == MODULE_STATE_GOING ||
	    mod->state == MODULE_STATE_COMING) {
3508
		buf[bx++] = '(';
3509
		bx += module_flags_taint(mod, buf + bx);
3510 3511 3512 3513 3514 3515
		/* 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++] = '+';
3516 3517 3518 3519 3520 3521 3522
		buf[bx++] = ')';
	}
	buf[bx] = '\0';

	return buf;
}

3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540
#ifdef CONFIG_PROC_FS
/* Called by the /proc file system to return a list of modules. */
static void *m_start(struct seq_file *m, loff_t *pos)
{
	mutex_lock(&module_mutex);
	return seq_list_start(&modules, *pos);
}

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

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

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static int m_show(struct seq_file *m, void *p)
{
	struct module *mod = list_entry(p, struct module, list);
3544 3545
	char buf[8];

3546
	seq_printf(m, "%s %u",
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Linus Torvalds 已提交
3547 3548 3549 3550 3551 3552 3553 3554 3555
		   mod->name, mod->init_size + mod->core_size);
	print_unload_info(m, mod);

	/* Informative for users. */
	seq_printf(m, " %s",
		   mod->state == MODULE_STATE_GOING ? "Unloading":
		   mod->state == MODULE_STATE_COMING ? "Loading":
		   "Live");
	/* Used by oprofile and other similar tools. */
3556
	seq_printf(m, " 0x%pK", mod->module_core);
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Linus Torvalds 已提交
3557

3558 3559
	/* Taints info */
	if (mod->taints)
3560
		seq_printf(m, " %s", module_flags(mod, buf));
3561

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	seq_printf(m, "\n");
	return 0;
}

/* Format: modulename size refcount deps address

   Where refcount is a number or -, and deps is a comma-separated list
   of depends or -.
*/
3571
static const struct seq_operations modules_op = {
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3572 3573 3574 3575 3576 3577
	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= m_show
};

3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597
static int modules_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &modules_op);
}

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

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

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

3604
	preempt_disable();
3605
	list_for_each_entry_rcu(mod, &modules, list) {
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Linus Torvalds 已提交
3606 3607
		if (mod->num_exentries == 0)
			continue;
3608

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3609 3610 3611 3612 3613 3614
		e = search_extable(mod->extable,
				   mod->extable + mod->num_exentries - 1,
				   addr);
		if (e)
			break;
	}
3615
	preempt_enable();
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3616 3617

	/* Now, if we found one, we are running inside it now, hence
3618
	   we cannot unload the module, hence no refcnt needed. */
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3619 3620 3621
	return e;
}

3622
/*
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3623 3624 3625 3626 3627
 * 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).
3628
 */
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Rusty Russell 已提交
3629
bool is_module_address(unsigned long addr)
3630
{
R
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3631
	bool ret;
3632

3633
	preempt_disable();
R
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3634
	ret = __module_address(addr) != NULL;
3635
	preempt_enable();
3636

R
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3637
	return ret;
3638 3639
}

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3640 3641 3642 3643 3644 3645 3646
/*
 * __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.
 */
3647
struct module *__module_address(unsigned long addr)
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3648 3649 3650
{
	struct module *mod;

3651 3652 3653
	if (addr < module_addr_min || addr > module_addr_max)
		return NULL;

3654
	list_for_each_entry_rcu(mod, &modules, list)
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Rusty Russell 已提交
3655 3656
		if (within_module_core(addr, mod)
		    || within_module_init(addr, mod))
L
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3657 3658 3659
			return mod;
	return NULL;
}
3660
EXPORT_SYMBOL_GPL(__module_address);
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3661

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3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696 3697 3698
/*
 * 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;
}
3699
EXPORT_SYMBOL_GPL(__module_text_address);
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3700

L
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3701 3702 3703 3704
/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
	struct module *mod;
3705
	char buf[8];
L
Linus Torvalds 已提交
3706

3707
	printk(KERN_DEFAULT "Modules linked in:");
3708 3709 3710
	/* Most callers should already have preempt disabled, but make sure */
	preempt_disable();
	list_for_each_entry_rcu(mod, &modules, list)
3711
		printk(" %s%s", mod->name, module_flags(mod, buf));
3712
	preempt_enable();
3713 3714
	if (last_unloaded_module[0])
		printk(" [last unloaded: %s]", last_unloaded_module);
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3715 3716 3717 3718
	printk("\n");
}

#ifdef CONFIG_MODVERSIONS
3719 3720 3721 3722 3723 3724
/* 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,
3725
		   struct tracepoint * const *tp)
3726 3727 3728
{
}
EXPORT_SYMBOL(module_layout);
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3729
#endif
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