/*

Copyright (C) 2002 Richard Henderson

Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.

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

*/

#include <linux/export.h>

#include <linux/moduleloader.h>

#include <linux/ftrace_event.h>

#include <linux/init.h>

#include <linux/kallsyms.h>

#include <linux/file.h>

#include <linux/fs.h>

#include <linux/sysfs.h>

#include <linux/kernel.h>

#include <linux/slab.h>

#include <linux/vmalloc.h>

#include <linux/elf.h>

#include <linux/proc_fs.h>

#include <linux/security.h>

#include <linux/seq_file.h>

#include <linux/syscalls.h>

#include <linux/fcntl.h>

#include <linux/rcupdate.h>

#include <linux/capability.h>

#include <linux/cpu.h>

#include <linux/moduleparam.h>

#include <linux/errno.h>

#include <linux/err.h>

#include <linux/vermagic.h>

#include <linux/notifier.h>

#include <linux/sched.h>

#include <linux/stop_machine.h>

#include <linux/device.h>

#include <linux/string.h>

#include <linux/mutex.h>

#include <linux/rculist.h>

#include <asm/uaccess.h>

#include <asm/cacheflush.h>

#include <asm/mmu_context.h>

#include <linux/license.h>

#include <asm/sections.h>

#include <linux/tracepoint.h>

#include <linux/ftrace.h>

#include <linux/async.h>

#include <linux/percpu.h>

#include <linux/kmemleak.h>

#include <linux/jump_label.h>

#include <linux/pfn.h>

#include <linux/bsearch.h>

#include <linux/fips.h>

#include <uapi/linux/module.h>

#include "module-internal.h"

#define CREATE_TRACE_POINTS

#include <trace/events/module.h>

#ifndef ARCH_SHF_SMALL

#define ARCH_SHF_SMALL 0

#endif

/*

* 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))

/* If this is set, the section belongs in the init part of the module */

#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))

/*

* Mutex protects:

* 1) List of modules (also safely readable with preempt_disable),

* 2) module_use links,

* 3) module_addr_min/module_addr_max.

* (delete uses stop_machine/add uses RCU list operations). */

DEFINE_MUTEX(module_mutex);

EXPORT_SYMBOL_GPL(module_mutex);

static LIST_HEAD(modules);

#ifdef CONFIG_KGDB_KDB

struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */

#endif /* CONFIG_KGDB_KDB */

#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 */

/* Block module loading/unloading? */

int modules_disabled = 0;

core_param(nomodule, modules_disabled, bint, 0);

/* Waiting for a module to finish initializing? */

static DECLARE_WAIT_QUEUE_HEAD(module_wq);

static BLOCKING_NOTIFIER_HEAD(module_notify_list);

/* Bounds of module allocation, for speeding __module_address.

* Protected by module_mutex. */

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

int register_module_notifier(struct notifier_block * nb)

{

return blocking_notifier_chain_register(&module_notify_list, nb);

}

EXPORT_SYMBOL(register_module_notifier);

int unregister_module_notifier(struct notifier_block * nb)

{

return blocking_notifier_chain_unregister(&module_notify_list, nb);

}

EXPORT_SYMBOL(unregister_module_notifier);

struct load_info {

Elf_Ehdr *hdr;

unsigned long len;

Elf_Shdr *sechdrs;

char *secstrings, *strtab;

unsigned long symoffs, stroffs;

struct _ddebug *debug;

unsigned int num_debug;

bool sig_ok;

struct {

unsigned int sym, str, mod, vers, info, pcpu;

} index;

};

/* We require a truly strong try_module_get(): 0 means failure due to

ongoing or failed initialization etc. */

static inline int strong_try_module_get(struct module *mod)

{

BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);

if (mod && mod->state == MODULE_STATE_COMING)

return -EBUSY;

if (try_module_get(mod))

return 0;

else

return -ENOENT;

}

static inline void add_taint_module(struct module *mod, unsigned flag,

enum lockdep_ok lockdep_ok)

{

add_taint(flag, lockdep_ok);

mod->taints |= (1U << flag);

}

/*

* 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.

*/

void __module_put_and_exit(struct module *mod, long code)

{

module_put(mod);

do_exit(code);

}

EXPORT_SYMBOL(__module_put_and_exit);

/* Find a module section: 0 means not found. */

static unsigned int find_sec(const struct load_info *info, const char *name)

{

unsigned int i;

for (i = 1; i < info->hdr->e_shnum; i++) {

Elf_Shdr *shdr = &info->sechdrs[i];

/* Alloc bit cleared means "ignore it." */

if ((shdr->sh_flags & SHF_ALLOC)

&& strcmp(info->secstrings + shdr->sh_name, name) == 0)

return i;

}

return 0;

}

/* Find a module section, or NULL. */

static void *section_addr(const struct load_info *info, const char *name)

{

/* Section 0 has sh_addr 0. */

return (void *)info->sechdrs[find_sec(info, name)].sh_addr;

}

/* Find a module section, or NULL. Fill in number of "objects" in section. */

static void *section_objs(const struct load_info *info,

const char *name,

size_t object_size,

unsigned int *num)

{

unsigned int sec = find_sec(info, name);

/* Section 0 has sh_addr 0 and sh_size 0. */

*num = info->sechdrs[sec].sh_size / object_size;

return (void *)info->sechdrs[sec].sh_addr;

}

/* 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[];

extern const struct kernel_symbol __start___ksymtab_gpl_future[];

extern const struct kernel_symbol __stop___ksymtab_gpl_future[];

extern const unsigned long __start___kcrctab[];

extern const unsigned long __start___kcrctab_gpl[];

extern const unsigned long __start___kcrctab_gpl_future[];

#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[];

extern const unsigned long __start___kcrctab_unused[];

extern const unsigned long __start___kcrctab_unused_gpl[];

#endif

#ifndef CONFIG_MODVERSIONS

#define symversion(base, idx) NULL

#else

#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)

#endif

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,

void *data),

void *data)

{

unsigned int j;

for (j = 0; j < arrsize; j++) {

if (fn(&arr[j], owner, data))

return true;

}

return false;

}

/* Returns true as soon as fn returns true, otherwise false. */

bool each_symbol_section(bool (*fn)(const struct symsearch *arr,

struct module *owner,

void *data),

void *data)

{

struct module *mod;

static const struct symsearch arr[] = {

{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,

NOT_GPL_ONLY, false },

{ __start___ksymtab_gpl, __stop___ksymtab_gpl,

__start___kcrctab_gpl,

GPL_ONLY, false },

{ __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,

__start___kcrctab_gpl_future,

WILL_BE_GPL_ONLY, false },

#ifdef CONFIG_UNUSED_SYMBOLS

{ __start___ksymtab_unused, __stop___ksymtab_unused,

__start___kcrctab_unused,

NOT_GPL_ONLY, true },

{ __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,

__start___kcrctab_unused_gpl,

GPL_ONLY, true },

#endif

};

if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))

return true;

list_for_each_entry_rcu(mod, &modules, list) {

struct symsearch arr[] = {

{ mod->syms, mod->syms + mod->num_syms, mod->crcs,

NOT_GPL_ONLY, false },

{ mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,

mod->gpl_crcs,

GPL_ONLY, false },

{ mod->gpl_future_syms,

mod->gpl_future_syms + mod->num_gpl_future_syms,

mod->gpl_future_crcs,

WILL_BE_GPL_ONLY, false },

#ifdef CONFIG_UNUSED_SYMBOLS

{ mod->unused_syms,

mod->unused_syms + mod->num_unused_syms,

mod->unused_crcs,

NOT_GPL_ONLY, true },

{ mod->unused_gpl_syms,

mod->unused_gpl_syms + mod->num_unused_gpl_syms,

mod->unused_gpl_crcs,

GPL_ONLY, true },

#endif

};

if (mod->state == MODULE_STATE_UNFORMED)

continue;

if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))

return true;

}

return false;

}

EXPORT_SYMBOL_GPL(each_symbol_section);

struct find_symbol_arg {

/* Input */

const char *name;

bool gplok;

bool warn;

/* Output */

struct module *owner;

const unsigned long *crc;

const struct kernel_symbol *sym;

};

static bool check_symbol(const struct symsearch *syms,

struct module *owner,

unsigned int symnum, void *data)

{

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);

}

}

#ifdef CONFIG_UNUSED_SYMBOLS

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");

}

#endif

fsa->owner = owner;

fsa->crc = symversion(syms->crcs, symnum);

fsa->sym = &syms->start[symnum];

return true;

}

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);

}

static bool find_symbol_in_section(const struct symsearch *syms,

struct module *owner,

void *data)

{

struct find_symbol_arg *fsa = data;

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;

return false;

}

/* Find a symbol and return it, along with, (optional) crc and

* (optional) module which owns it. Needs preempt disabled or module_mutex. */

const struct kernel_symbol *find_symbol(const char *name,

struct module **owner,

const unsigned long **crc,

bool gplok,

bool warn)

{

struct find_symbol_arg fsa;

fsa.name = name;

fsa.gplok = gplok;

fsa.warn = warn;

if (each_symbol_section(find_symbol_in_section, &fsa)) {

if (owner)

*owner = fsa.owner;

if (crc)

*crc = fsa.crc;

return fsa.sym;

}

pr_debug("Failed to find symbol %s\n", name);

return NULL;

}

EXPORT_SYMBOL_GPL(find_symbol);

/* Search for module by name: must hold module_mutex. */

static struct module *find_module_all(const char *name, size_t len,

bool even_unformed)

{

struct module *mod;

list_for_each_entry(mod, &modules, list) {

if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)

continue;

if (strlen(mod->name) == len && !memcmp(mod->name, name, len))

return mod;

}

return NULL;

}

struct module *find_module(const char *name)

{

return find_module_all(name, strlen(name), false);

}

EXPORT_SYMBOL_GPL(find_module);

#ifdef CONFIG_SMP

static inline void __percpu *mod_percpu(struct module *mod)

{

return mod->percpu;

}

static int percpu_modalloc(struct module *mod, struct load_info *info)

{

Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];

unsigned long align = pcpusec->sh_addralign;

if (!pcpusec->sh_size)

return 0;

if (align > PAGE_SIZE) {

printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",

mod->name, align, PAGE_SIZE);

align = PAGE_SIZE;

}

mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);

if (!mod->percpu) {

printk(KERN_WARNING

"%s: Could not allocate %lu bytes percpu data\n",

mod->name, (unsigned long)pcpusec->sh_size);

return -ENOMEM;

}

mod->percpu_size = pcpusec->sh_size;

return 0;

}

static void percpu_modfree(struct module *mod)

{

free_percpu(mod->percpu);

}

static unsigned int find_pcpusec(struct load_info *info)

{

return find_sec(info, ".data..percpu");

}

static void percpu_modcopy(struct module *mod,

const void *from, unsigned long size)

{

int cpu;

for_each_possible_cpu(cpu)

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

}

/**

* 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->state == MODULE_STATE_UNFORMED)

continue;

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;

}

#else /* ... !CONFIG_SMP */

static inline void __percpu *mod_percpu(struct module *mod)

{

return NULL;

}

static int percpu_modalloc(struct module *mod, struct load_info *info)

{

/* UP modules shouldn't have this section: ENOMEM isn't quite right */

if (info->sechdrs[info->index.pcpu].sh_size != 0)

return -ENOMEM;

return 0;

}

static inline void percpu_modfree(struct module *mod)

{

}

static unsigned int find_pcpusec(struct load_info *info)

{

return 0;

}

static inline void percpu_modcopy(struct module *mod,

const void *from, unsigned long size)

{

/* pcpusec should be 0, and size of that section should be 0. */

BUG_ON(size != 0);

}

bool is_module_percpu_address(unsigned long addr)

{

return false;

}

#endif /* CONFIG_SMP */

#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, \

struct module_kobject *mk, char *buffer) \

{ \

return sprintf(buffer, "%s\n", mk->mod->field); \

} \

static int modinfo_##field##_exists(struct module *mod) \

{ \

return mod->field != NULL; \

} \

static void free_modinfo_##field(struct module *mod) \

{ \

kfree(mod->field); \

mod->field = NULL; \

} \

static struct module_attribute modinfo_##field = { \

.attr = { .name = __stringify(field), .mode = 0444 }, \

.show = show_modinfo_##field, \

.setup = setup_modinfo_##field, \

.test = modinfo_##field##_exists, \

.free = free_modinfo_##field, \

};

MODINFO_ATTR(version);

MODINFO_ATTR(srcversion);

static char last_unloaded_module[MODULE_NAME_LEN+1];

#ifdef CONFIG_MODULE_UNLOAD

EXPORT_TRACEPOINT_SYMBOL(module_get);

/* Init the unload section of the module. */

static int module_unload_init(struct module *mod)

{

mod->refptr = alloc_percpu(struct module_ref);

if (!mod->refptr)

return -ENOMEM;

INIT_LIST_HEAD(&mod->source_list);

INIT_LIST_HEAD(&mod->target_list);

/* Hold reference count during initialization. */

__this_cpu_write(mod->refptr->incs, 1);

/* Backwards compatibility macros put refcount during init. */

mod->waiter = current;

return 0;

}

/* Does a already use b? */

static int already_uses(struct module *a, struct module *b)

{

struct module_use *use;

list_for_each_entry(use, &b->source_list, source_list) {

if (use->source == a) {

pr_debug("%s uses %s!\n", a->name, b->name);

return 1;

}

}

pr_debug("%s does not use %s!\n", a->name, b->name);

return 0;

}

/*

* 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;

pr_debug("Allocating new usage for %s.\n", a->name);

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;

}

/* Module a uses b: caller needs module_mutex() */

int ref_module(struct module *a, struct module *b)

{

int err;

if (b == NULL || already_uses(a, b))

return 0;

/* If module isn't available, we fail. */

err = strong_try_module_get(b);

if (err)

return err;

err = add_module_usage(a, b);

if (err) {

module_put(b);

return err;

}

return 0;

}

EXPORT_SYMBOL_GPL(ref_module);

/* Clear the unload stuff of the module. */

static void module_unload_free(struct module *mod)

{

struct module_use *use, *tmp;

mutex_lock(&module_mutex);

list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {

struct module *i = use->target;

pr_debug("%s unusing %s\n", mod->name, i->name);

module_put(i);

list_del(&use->source_list);

list_del(&use->target_list);

kfree(use);

}

mutex_unlock(&module_mutex);

free_percpu(mod->refptr);

}

#ifdef CONFIG_MODULE_FORCE_UNLOAD

static inline int try_force_unload(unsigned int flags)

{

int ret = (flags & O_TRUNC);

if (ret)

add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);

return ret;

}

#else

static inline int try_force_unload(unsigned int flags)

{

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;

/* If it's not unused, quit unless we're forcing. */

if (module_refcount(sref->mod) != 0) {

if (!(*sref->forced = try_force_unload(sref->flags)))

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)

{

if (flags & O_NONBLOCK) {

struct stopref sref = { mod, flags, forced };

return stop_machine(__try_stop_module, &sref, NULL);

} else {

/* We don't need to stop the machine for this. */

mod->state = MODULE_STATE_GOING;

synchronize_sched();

return 0;

}

}

unsigned long module_refcount(struct module *mod)

{

unsigned long incs = 0, decs = 0;

int cpu;

for_each_possible_cpu(cpu)

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;

}

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)

{

/* Since we might sleep for some time, release the mutex first */

mutex_unlock(&module_mutex);

for (;;) {

pr_debug("Looking at refcount...\n");

set_current_state(TASK_UNINTERRUPTIBLE);

if (module_refcount(mod) == 0)

break;

schedule();

}

current->state = TASK_RUNNING;

mutex_lock(&module_mutex);

}

SYSCALL_DEFINE2(delete_module, const char __user *, name_user,

unsigned int, flags)

{

struct module *mod;

char name[MODULE_NAME_LEN];

int ret, forced = 0;

if (!capable(CAP_SYS_MODULE) || modules_disabled)

return -EPERM;

if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)

return -EFAULT;

name[MODULE_NAME_LEN-1] = '\0';

if (mutex_lock_interruptible(&module_mutex) != 0)

return -EINTR;

mod = find_module(name);

if (!mod) {

ret = -ENOENT;

goto out;

}

if (!list_empty(&mod->source_list)) {

/* 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 */

pr_debug("%s already dying\n", mod->name);

ret = -EBUSY;

goto out;

}

/* If it has an init func, it must have an exit func to unload */

if (mod->init && !mod->exit) {

forced = try_force_unload(flags);

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);

mutex_unlock(&module_mutex);

/* Final destruction now no one is using it. */

if (mod->exit != NULL)

mod->exit();

blocking_notifier_call_chain(&module_notify_list,

MODULE_STATE_GOING, mod);

async_synchronize_full();

/* Store the name of the last unloaded module for diagnostic purposes */

strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));

free_module(mod);

return 0;

out:

mutex_unlock(&module_mutex);

return ret;

}

static inline void print_unload_info(struct seq_file *m, struct module *mod)

{

struct module_use *use;

int printed_something = 0;

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

/* Always include a trailing , so userspace can differentiate

between this and the old multi-field proc format. */

list_for_each_entry(use, &mod->source_list, source_list) {

printed_something = 1;

seq_printf(m, "%s,", use->source->name);

}

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;

preempt_disable();

if (!find_symbol(symbol, &owner, NULL, true, false))

BUG();

module_put(owner);

preempt_enable();

}

EXPORT_SYMBOL(__symbol_put);

/* Note this assumes addr is a function, which it currently always is. */

void symbol_put_addr(void *addr)

{

struct module *modaddr;

unsigned long a = (unsigned long)dereference_function_descriptor(addr);

if (core_kernel_text(a))

return;

/* module_text_address is safe here: we're supposed to have reference

* to module from symbol_get, so it can't go away. */

modaddr = __module_text_address(a);

BUG_ON(!modaddr);

module_put(modaddr);

}

EXPORT_SYMBOL_GPL(symbol_put_addr);

static ssize_t show_refcnt(struct module_attribute *mattr,

struct module_kobject *mk, char *buffer)

{

return sprintf(buffer, "%lu\n", module_refcount(mk->mod));

}

static struct module_attribute modinfo_refcnt =

__ATTR(refcnt, 0444, show_refcnt, NULL);

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);

void module_put(struct module *module)

{