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linux/kernel/module.c
Alexey Dobriyan 256e2fdf03 Fix Off-by-one in /sys/module/*/refcnt 
sysfs internals were changed to not pin module in question.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Acked-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-08-22 14:35:35 -07:00

2477 lines
63 KiB
C
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/*
Copyright (C) 2002 Richard Henderson
Copyright (C) 2001 Rusty Russell, 2002 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/module.h>
#include <linux/moduleloader.h>
#include <linux/init.h>
#include <linux/kallsyms.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/elf.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/unwind.h>
#include <asm/uaccess.h>
#include <asm/semaphore.h>
#include <asm/cacheflush.h>
#include <linux/license.h>
extern int module_sysfs_initialized;
#if 0
#define DEBUGP printk
#else
#define DEBUGP(fmt , a...)
#endif
#ifndef ARCH_SHF_SMALL
#define ARCH_SHF_SMALL 0
#endif
/* If this is set, the section belongs in the init part of the module */
#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
/* List of modules, protected by module_mutex or preempt_disable
* (add/delete uses stop_machine). */
static DEFINE_MUTEX(module_mutex);
static LIST_HEAD(modules);
static BLOCKING_NOTIFIER_HEAD(module_notify_list);
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);
/* We require a truly strong try_module_get() */
static inline int strong_try_module_get(struct module *mod)
{
if (mod && mod->state == MODULE_STATE_COMING)
return 0;
return try_module_get(mod);
}
static inline void add_taint_module(struct module *mod, unsigned flag)
{
add_taint(flag);
mod->taints |= 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(Elf_Ehdr *hdr,
Elf_Shdr *sechdrs,
const char *secstrings,
const char *name)
{
unsigned int i;
for (i = 1; i < hdr->e_shnum; i++)
/* Alloc bit cleared means "ignore it." */
if ((sechdrs[i].sh_flags & SHF_ALLOC)
&& strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
return i;
return 0;
}
/* 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 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 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[];
extern const unsigned long __start___kcrctab_unused[];
extern const unsigned long __start___kcrctab_unused_gpl[];
#ifndef CONFIG_MODVERSIONS
#define symversion(base, idx) NULL
#else
#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
#endif
/* 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)
{
const struct kernel_symbol *ks = start;
for (; ks < stop; ks++)
if (strcmp(ks->name, name) == 0)
return ks;
return NULL;
}
static void printk_unused_warning(const char *name)
{
printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
"however this module is using it.\n", 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");
}
/* Find a symbol, return value, crc and module which owns it */
static unsigned long __find_symbol(const char *name,
struct module **owner,
const unsigned long **crc,
int gplok)
{
struct module *mod;
const struct kernel_symbol *ks;
/* Core kernel first. */
*owner = NULL;
ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
if (ks) {
*crc = symversion(__start___kcrctab, (ks - __start___ksymtab));
return ks->value;
}
if (gplok) {
ks = lookup_symbol(name, __start___ksymtab_gpl,
__stop___ksymtab_gpl);
if (ks) {
*crc = symversion(__start___kcrctab_gpl,
(ks - __start___ksymtab_gpl));
return ks->value;
}
}
ks = lookup_symbol(name, __start___ksymtab_gpl_future,
__stop___ksymtab_gpl_future);
if (ks) {
if (!gplok) {
printk(KERN_WARNING "Symbol %s is being used "
"by a non-GPL module, which will not "
"be allowed in the future\n", name);
printk(KERN_WARNING "Please see the file "
"Documentation/feature-removal-schedule.txt "
"in the kernel source tree for more "
"details.\n");
}
*crc = symversion(__start___kcrctab_gpl_future,
(ks - __start___ksymtab_gpl_future));
return ks->value;
}
ks = lookup_symbol(name, __start___ksymtab_unused,
__stop___ksymtab_unused);
if (ks) {
printk_unused_warning(name);
*crc = symversion(__start___kcrctab_unused,
(ks - __start___ksymtab_unused));
return ks->value;
}
if (gplok)
ks = lookup_symbol(name, __start___ksymtab_unused_gpl,
__stop___ksymtab_unused_gpl);
if (ks) {
printk_unused_warning(name);
*crc = symversion(__start___kcrctab_unused_gpl,
(ks - __start___ksymtab_unused_gpl));
return ks->value;
}
/* Now try modules. */
list_for_each_entry(mod, &modules, list) {
*owner = mod;
ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
if (ks) {
*crc = symversion(mod->crcs, (ks - mod->syms));
return ks->value;
}
if (gplok) {
ks = lookup_symbol(name, mod->gpl_syms,
mod->gpl_syms + mod->num_gpl_syms);
if (ks) {
*crc = symversion(mod->gpl_crcs,
(ks - mod->gpl_syms));
return ks->value;
}
}
ks = lookup_symbol(name, mod->unused_syms, mod->unused_syms + mod->num_unused_syms);
if (ks) {
printk_unused_warning(name);
*crc = symversion(mod->unused_crcs, (ks - mod->unused_syms));
return ks->value;
}
if (gplok) {
ks = lookup_symbol(name, mod->unused_gpl_syms,
mod->unused_gpl_syms + mod->num_unused_gpl_syms);
if (ks) {
printk_unused_warning(name);
*crc = symversion(mod->unused_gpl_crcs,
(ks - mod->unused_gpl_syms));
return ks->value;
}
}
ks = lookup_symbol(name, mod->gpl_future_syms,
(mod->gpl_future_syms +
mod->num_gpl_future_syms));
if (ks) {
if (!gplok) {
printk(KERN_WARNING "Symbol %s is being used "
"by a non-GPL module, which will not "
"be allowed in the future\n", name);
printk(KERN_WARNING "Please see the file "
"Documentation/feature-removal-schedule.txt "
"in the kernel source tree for more "
"details.\n");
}
*crc = symversion(mod->gpl_future_crcs,
(ks - mod->gpl_future_syms));
return ks->value;
}
}
DEBUGP("Failed to find symbol %s\n", name);
return 0;
}
/* Search for module by name: must hold module_mutex. */
static struct module *find_module(const char *name)
{
struct module *mod;
list_for_each_entry(mod, &modules, list) {
if (strcmp(mod->name, name) == 0)
return mod;
}
return NULL;
}
#ifdef CONFIG_SMP
/* Number of blocks used and allocated. */
static unsigned int pcpu_num_used, pcpu_num_allocated;
/* Size of each block. -ve means used. */
static int *pcpu_size;
static int split_block(unsigned int i, unsigned short size)
{
/* Reallocation required? */
if (pcpu_num_used + 1 > pcpu_num_allocated) {
int *new;
new = krealloc(pcpu_size, sizeof(new[0])*pcpu_num_allocated*2,
GFP_KERNEL);
if (!new)
return 0;
pcpu_num_allocated *= 2;
pcpu_size = new;
}
/* Insert a new subblock */
memmove(&pcpu_size[i+1], &pcpu_size[i],
sizeof(pcpu_size[0]) * (pcpu_num_used - i));
pcpu_num_used++;
pcpu_size[i+1] -= size;
pcpu_size[i] = size;
return 1;
}
static inline unsigned int block_size(int val)
{
if (val < 0)
return -val;
return val;
}
/* Created by linker magic */
extern char __per_cpu_start[], __per_cpu_end[];
static void *percpu_modalloc(unsigned long size, unsigned long align,
const char *name)
{
unsigned long extra;
unsigned int i;
void *ptr;
if (align > PAGE_SIZE) {
printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
name, align, PAGE_SIZE);
align = PAGE_SIZE;
}
ptr = __per_cpu_start;
for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
/* Extra for alignment requirement. */
extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr;
BUG_ON(i == 0 && extra != 0);
if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size)
continue;
/* Transfer extra to previous block. */
if (pcpu_size[i-1] < 0)
pcpu_size[i-1] -= extra;
else
pcpu_size[i-1] += extra;
pcpu_size[i] -= extra;
ptr += extra;
/* Split block if warranted */
if (pcpu_size[i] - size > sizeof(unsigned long))
if (!split_block(i, size))
return NULL;
/* Mark allocated */
pcpu_size[i] = -pcpu_size[i];
return ptr;
}
printk(KERN_WARNING "Could not allocate %lu bytes percpu data\n",
size);
return NULL;
}
static void percpu_modfree(void *freeme)
{
unsigned int i;
void *ptr = __per_cpu_start + block_size(pcpu_size[0]);
/* First entry is core kernel percpu data. */
for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
if (ptr == freeme) {
pcpu_size[i] = -pcpu_size[i];
goto free;
}
}
BUG();
free:
/* Merge with previous? */
if (pcpu_size[i-1] >= 0) {
pcpu_size[i-1] += pcpu_size[i];
pcpu_num_used--;
memmove(&pcpu_size[i], &pcpu_size[i+1],
(pcpu_num_used - i) * sizeof(pcpu_size[0]));
i--;
}
/* Merge with next? */
if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) {
pcpu_size[i] += pcpu_size[i+1];
pcpu_num_used--;
memmove(&pcpu_size[i+1], &pcpu_size[i+2],
(pcpu_num_used - (i+1)) * sizeof(pcpu_size[0]));
}
}
static unsigned int find_pcpusec(Elf_Ehdr *hdr,
Elf_Shdr *sechdrs,
const char *secstrings)
{
return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
}
static int percpu_modinit(void)
{
pcpu_num_used = 2;
pcpu_num_allocated = 2;
pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated,
GFP_KERNEL);
/* Static in-kernel percpu data (used). */
pcpu_size[0] = -(__per_cpu_end-__per_cpu_start);
/* Free room. */
pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0];
if (pcpu_size[1] < 0) {
printk(KERN_ERR "No per-cpu room for modules.\n");
pcpu_num_used = 1;
}
return 0;
}
__initcall(percpu_modinit);
#else /* ... !CONFIG_SMP */
static inline void *percpu_modalloc(unsigned long size, unsigned long align,
const char *name)
{
return NULL;
}
static inline void percpu_modfree(void *pcpuptr)
{
BUG();
}
static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
Elf_Shdr *sechdrs,
const char *secstrings)
{
return 0;
}
static inline void percpu_modcopy(void *pcpudst, const void *src,
unsigned long size)
{
/* pcpusec should be 0, and size of that section should be 0. */
BUG_ON(size != 0);
}
#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 *mod, char *buffer) \
{ \
return sprintf(buffer, "%s\n", 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);
#ifdef CONFIG_MODULE_UNLOAD
/* Init the unload section of the module. */
static void module_unload_init(struct module *mod)
{
unsigned int i;
INIT_LIST_HEAD(&mod->modules_which_use_me);
for (i = 0; i < NR_CPUS; i++)
local_set(&mod->ref[i].count, 0);
/* Hold reference count during initialization. */
local_set(&mod->ref[raw_smp_processor_id()].count, 1);
/* Backwards compatibility macros put refcount during init. */
mod->waiter = current;
}
/* modules using other modules */
struct module_use
{
struct list_head list;
struct module *module_which_uses;
};
/* 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->modules_which_use_me, list) {
if (use->module_which_uses == a) {
DEBUGP("%s uses %s!\n", a->name, b->name);
return 1;
}
}
DEBUGP("%s does not use %s!\n", a->name, b->name);
return 0;
}
/* Module a uses b */
static int use_module(struct module *a, struct module *b)
{
struct module_use *use;
int no_warn;
if (b == NULL || already_uses(a, b)) return 1;
if (!strong_try_module_get(b))
return 0;
DEBUGP("Allocating new usage for %s.\n", a->name);
use = kmalloc(sizeof(*use), GFP_ATOMIC);
if (!use) {
printk("%s: out of memory loading\n", a->name);
module_put(b);
return 0;
}
use->module_which_uses = a;
list_add(&use->list, &b->modules_which_use_me);
no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name);
return 1;
}
/* Clear the unload stuff of the module. */
static void module_unload_free(struct module *mod)
{
struct module *i;
list_for_each_entry(i, &modules, list) {
struct module_use *use;
list_for_each_entry(use, &i->modules_which_use_me, list) {
if (use->module_which_uses == mod) {
DEBUGP("%s unusing %s\n", mod->name, i->name);
module_put(i);
list_del(&use->list);
kfree(use);
sysfs_remove_link(i->holders_dir, mod->name);
/* There can be at most one match. */
break;
}
}
}
}
#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);
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 are told to block. */
if ((sref->flags & O_NONBLOCK) && 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)
{
struct stopref sref = { mod, flags, forced };
return stop_machine_run(__try_stop_module, &sref, NR_CPUS);
}
unsigned int module_refcount(struct module *mod)
{
unsigned int i, total = 0;
for (i = 0; i < NR_CPUS; i++)
total += local_read(&mod->ref[i].count);
return total;
}
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, drop the semaphore first */
mutex_unlock(&module_mutex);
for (;;) {
DEBUGP("Looking at refcount...\n");
set_current_state(TASK_UNINTERRUPTIBLE);
if (module_refcount(mod) == 0)
break;
schedule();
}
current->state = TASK_RUNNING;
mutex_lock(&module_mutex);
}
asmlinkage long
sys_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))
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->modules_which_use_me)) {
/* 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 */
DEBUGP("%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 != NULL && mod->exit == NULL)
|| mod->unsafe) {
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);
/* Final destruction now noone is using it. */
if (mod->exit != NULL) {
mutex_unlock(&module_mutex);
mod->exit();
mutex_lock(&module_mutex);
}
free_module(mod);
out:
mutex_unlock(&module_mutex);
return ret;
}
static void print_unload_info(struct seq_file *m, struct module *mod)
{
struct module_use *use;
int printed_something = 0;
seq_printf(m, " %u ", 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->modules_which_use_me, list) {
printed_something = 1;
seq_printf(m, "%s,", use->module_which_uses->name);
}
if (mod->unsafe) {
printed_something = 1;
seq_printf(m, "[unsafe],");
}
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;
const unsigned long *crc;
preempt_disable();
if (!__find_symbol(symbol, &owner, &crc, 1))
BUG();
module_put(owner);
preempt_enable();
}
EXPORT_SYMBOL(__symbol_put);
void symbol_put_addr(void *addr)
{
struct module *modaddr;
if (core_kernel_text((unsigned long)addr))
return;
if (!(modaddr = module_text_address((unsigned long)addr)))
BUG();
module_put(modaddr);
}
EXPORT_SYMBOL_GPL(symbol_put_addr);
static ssize_t show_refcnt(struct module_attribute *mattr,
struct module *mod, char *buffer)
{
return sprintf(buffer, "%u\n", module_refcount(mod));
}
static struct module_attribute refcnt = {
.attr = { .name = "refcnt", .mode = 0444 },
.show = show_refcnt,
};
void module_put(struct module *module)
{
if (module) {
unsigned int cpu = get_cpu();
local_dec(&module->ref[cpu].count);
/* Maybe they're waiting for us to drop reference? */
if (unlikely(!module_is_live(module)))
wake_up_process(module->waiter);
put_cpu();
}
}
EXPORT_SYMBOL(module_put);
#else /* !CONFIG_MODULE_UNLOAD */
static void print_unload_info(struct seq_file *m, struct module *mod)
{
/* We don't know the usage count, or what modules are using. */
seq_printf(m, " - -");
}
static inline void module_unload_free(struct module *mod)
{
}
static inline int use_module(struct module *a, struct module *b)
{
return strong_try_module_get(b);
}
static inline void module_unload_init(struct module *mod)
{
}
#endif /* CONFIG_MODULE_UNLOAD */
static ssize_t show_initstate(struct module_attribute *mattr,
struct module *mod, char *buffer)
{
const char *state = "unknown";
switch (mod->state) {
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);
}
static struct module_attribute initstate = {
.attr = { .name = "initstate", .mode = 0444 },
.show = show_initstate,
};
static struct module_attribute *modinfo_attrs[] = {
&modinfo_version,
&modinfo_srcversion,
&initstate,
#ifdef CONFIG_MODULE_UNLOAD
&refcnt,
#endif
NULL,
};
static const char vermagic[] = VERMAGIC_STRING;
#ifdef CONFIG_MODVERSIONS
static int check_version(Elf_Shdr *sechdrs,
unsigned int versindex,
const char *symname,
struct module *mod,
const unsigned long *crc)
{
unsigned int i, num_versions;
struct modversion_info *versions;
/* Exporting module didn't supply crcs? OK, we're already tainted. */
if (!crc)
return 1;
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;
if (versions[i].crc == *crc)
return 1;
printk("%s: disagrees about version of symbol %s\n",
mod->name, symname);
DEBUGP("Found checksum %lX vs module %lX\n",
*crc, versions[i].crc);
return 0;
}
/* Not in module's version table. OK, but that taints the kernel. */
if (!(tainted & TAINT_FORCED_MODULE))
printk("%s: no version for \"%s\" found: kernel tainted.\n",
mod->name, symname);
add_taint_module(mod, TAINT_FORCED_MODULE);
return 1;
}
static inline int check_modstruct_version(Elf_Shdr *sechdrs,
unsigned int versindex,
struct module *mod)
{
const unsigned long *crc;
struct module *owner;
if (!__find_symbol("struct_module", &owner, &crc, 1))
BUG();
return check_version(sechdrs, versindex, "struct_module", mod,
crc);
}
/* First part is kernel version, which we ignore. */
static inline int same_magic(const char *amagic, const char *bmagic)
{
amagic += strcspn(amagic, " ");
bmagic += strcspn(bmagic, " ");
return strcmp(amagic, bmagic) == 0;
}
#else
static inline int check_version(Elf_Shdr *sechdrs,
unsigned int versindex,
const char *symname,
struct module *mod,
const unsigned long *crc)
{
return 1;
}
static inline int check_modstruct_version(Elf_Shdr *sechdrs,
unsigned int versindex,
struct module *mod)
{
return 1;
}
static inline int same_magic(const char *amagic, const char *bmagic)
{
return strcmp(amagic, bmagic) == 0;
}
#endif /* CONFIG_MODVERSIONS */
/* Resolve a symbol for this module. I.e. if we find one, record usage.
Must be holding module_mutex. */
static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
unsigned int versindex,
const char *name,
struct module *mod)
{
struct module *owner;
unsigned long ret;
const unsigned long *crc;
ret = __find_symbol(name, &owner, &crc,
!(mod->taints & TAINT_PROPRIETARY_MODULE));
if (ret) {
/* use_module can fail due to OOM, or module unloading */
if (!check_version(sechdrs, versindex, name, mod, crc) ||
!use_module(mod, owner))
ret = 0;
}
return ret;
}
/*
* /sys/module/foo/sections stuff
* J. Corbet <corbet@lwn.net>
*/
#ifdef CONFIG_KALLSYMS
static ssize_t module_sect_show(struct module_attribute *mattr,
struct module *mod, char *buf)
{
struct module_sect_attr *sattr =
container_of(mattr, struct module_sect_attr, mattr);
return sprintf(buf, "0x%lx\n", sattr->address);
}
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
int section;
for (section = 0; section < sect_attrs->nsections; section++)
kfree(sect_attrs->attrs[section].name);
kfree(sect_attrs);
}
static void add_sect_attrs(struct module *mod, unsigned int nsect,
char *secstrings, Elf_Shdr *sechdrs)
{
unsigned int nloaded = 0, i, size[2];
struct module_sect_attrs *sect_attrs;
struct module_sect_attr *sattr;
struct attribute **gattr;
/* Count loaded sections and allocate structures */
for (i = 0; i < nsect; i++)
if (sechdrs[i].sh_flags & SHF_ALLOC)
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]);
sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
if (sect_attrs == NULL)
return;
/* Setup section attributes. */
sect_attrs->grp.name = "sections";
sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
sect_attrs->nsections = 0;
sattr = &sect_attrs->attrs[0];
gattr = &sect_attrs->grp.attrs[0];
for (i = 0; i < nsect; i++) {
if (! (sechdrs[i].sh_flags & SHF_ALLOC))
continue;
sattr->address = sechdrs[i].sh_addr;
sattr->name = kstrdup(secstrings + sechdrs[i].sh_name,
GFP_KERNEL);
if (sattr->name == NULL)
goto out;
sect_attrs->nsections++;
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:
free_sect_attrs(sect_attrs);
}
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. */
free_sect_attrs(mod->sect_attrs);
mod->sect_attrs = NULL;
}
}
#else
static inline void add_sect_attrs(struct module *mod, unsigned int nsect,
char *sectstrings, Elf_Shdr *sechdrs)
{
}
static inline void remove_sect_attrs(struct module *mod)
{
}
#endif /* CONFIG_KALLSYMS */
#ifdef CONFIG_SYSFS
int module_add_modinfo_attrs(struct module *mod)
{
struct module_attribute *attr;
struct module_attribute *temp_attr;
int error = 0;
int i;
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;
for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
if (!attr->test ||
(attr->test && attr->test(mod))) {
memcpy(temp_attr, attr, sizeof(*temp_attr));
error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
++temp_attr;
}
}
return error;
}
void module_remove_modinfo_attrs(struct module *mod)
{
struct module_attribute *attr;
int i;
for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
/* pick a field to test for end of list */
if (!attr->attr.name)
break;
sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
if (attr->free)
attr->free(mod);
}
kfree(mod->modinfo_attrs);
}
#endif
#ifdef CONFIG_SYSFS
int mod_sysfs_init(struct module *mod)
{
int err;
if (!module_sysfs_initialized) {
printk(KERN_ERR "%s: module sysfs not initialized\n",
mod->name);
err = -EINVAL;
goto out;
}
memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
err = kobject_set_name(&mod->mkobj.kobj, "%s", mod->name);
if (err)
goto out;
kobj_set_kset_s(&mod->mkobj, module_subsys);
mod->mkobj.mod = mod;
kobject_init(&mod->mkobj.kobj);
out:
return err;
}
int mod_sysfs_setup(struct module *mod,
struct kernel_param *kparam,
unsigned int num_params)
{
int err;
/* delay uevent until full sysfs population */
err = kobject_add(&mod->mkobj.kobj);
if (err)
goto out;
mod->holders_dir = kobject_add_dir(&mod->mkobj.kobj, "holders");
if (!mod->holders_dir) {
err = -ENOMEM;
goto out_unreg;
}
err = module_param_sysfs_setup(mod, kparam, num_params);
if (err)
goto out_unreg_holders;
err = module_add_modinfo_attrs(mod);
if (err)
goto out_unreg_param;
kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
return 0;
out_unreg_param:
module_param_sysfs_remove(mod);
out_unreg_holders:
kobject_unregister(mod->holders_dir);
out_unreg:
kobject_del(&mod->mkobj.kobj);
kobject_put(&mod->mkobj.kobj);
out:
return err;
}
#endif
static void mod_kobject_remove(struct module *mod)
{
module_remove_modinfo_attrs(mod);
module_param_sysfs_remove(mod);
kobject_unregister(mod->mkobj.drivers_dir);
kobject_unregister(mod->holders_dir);
kobject_unregister(&mod->mkobj.kobj);
}
/*
* 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);
return 0;
}
/* Free a module, remove from lists, etc (must hold module_mutex). */
static void free_module(struct module *mod)
{
/* Delete from various lists */
stop_machine_run(__unlink_module, mod, NR_CPUS);
remove_sect_attrs(mod);
mod_kobject_remove(mod);
unwind_remove_table(mod->unwind_info, 0);
/* Arch-specific cleanup. */
module_arch_cleanup(mod);
/* Module unload stuff */
module_unload_free(mod);
/* This may be NULL, but that's OK */
module_free(mod, mod->module_init);
kfree(mod->args);
if (mod->percpu)
percpu_modfree(mod->percpu);
/* Free lock-classes: */
lockdep_free_key_range(mod->module_core, mod->core_size);
/* Finally, free the core (containing the module structure) */
module_free(mod, mod->module_core);
}
void *__symbol_get(const char *symbol)
{
struct module *owner;
unsigned long value;
const unsigned long *crc;
preempt_disable();
value = __find_symbol(symbol, &owner, &crc, 1);
if (value && !strong_try_module_get(owner))
value = 0;
preempt_enable();
return (void *)value;
}
EXPORT_SYMBOL_GPL(__symbol_get);
/*
* Ensure that an exported symbol [global namespace] does not already exist
* in the kernel or in some other module's exported symbol table.
*/
static int verify_export_symbols(struct module *mod)
{
const char *name = NULL;
unsigned long i, ret = 0;
struct module *owner;
const unsigned long *crc;
for (i = 0; i < mod->num_syms; i++)
if (__find_symbol(mod->syms[i].name, &owner, &crc, 1)) {
name = mod->syms[i].name;
ret = -ENOEXEC;
goto dup;
}
for (i = 0; i < mod->num_gpl_syms; i++)
if (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)) {
name = mod->gpl_syms[i].name;
ret = -ENOEXEC;
goto dup;
}
dup:
if (ret)
printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
mod->name, name, module_name(owner));
return ret;
}
/* Change all symbols so that sh_value encodes the pointer directly. */
static int simplify_symbols(Elf_Shdr *sechdrs,
unsigned int symindex,
const char *strtab,
unsigned int versindex,
unsigned int pcpuindex,
struct module *mod)
{
Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
unsigned long secbase;
unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
int ret = 0;
for (i = 1; i < n; i++) {
switch (sym[i].st_shndx) {
case SHN_COMMON:
/* We compiled with -fno-common. These are not
supposed to happen. */
DEBUGP("Common symbol: %s\n", strtab + sym[i].st_name);
printk("%s: please compile with -fno-common\n",
mod->name);
ret = -ENOEXEC;
break;
case SHN_ABS:
/* Don't need to do anything */
DEBUGP("Absolute symbol: 0x%08lx\n",
(long)sym[i].st_value);
break;
case SHN_UNDEF:
sym[i].st_value
= resolve_symbol(sechdrs, versindex,
strtab + sym[i].st_name, mod);
/* Ok if resolved. */
if (sym[i].st_value != 0)
break;
/* Ok if weak. */
if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
break;
printk(KERN_WARNING "%s: Unknown symbol %s\n",
mod->name, strtab + sym[i].st_name);
ret = -ENOENT;
break;
default:
/* Divert to percpu allocation if a percpu var. */
if (sym[i].st_shndx == pcpuindex)
secbase = (unsigned long)mod->percpu;
else
secbase = sechdrs[sym[i].st_shndx].sh_addr;
sym[i].st_value += secbase;
break;
}
}
return ret;
}
/* Update size with this section: return offset. */
static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
{
long ret;
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. */
static void layout_sections(struct module *mod,
const Elf_Ehdr *hdr,
Elf_Shdr *sechdrs,
const char *secstrings)
{
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;
for (i = 0; i < hdr->e_shnum; i++)
sechdrs[i].sh_entsize = ~0UL;
DEBUGP("Core section allocation order:\n");
for (m = 0; m < ARRAY_SIZE(masks); ++m) {
for (i = 0; i < hdr->e_shnum; ++i) {
Elf_Shdr *s = &sechdrs[i];
if ((s->sh_flags & masks[m][0]) != masks[m][0]
|| (s->sh_flags & masks[m][1])
|| s->sh_entsize != ~0UL
|| strncmp(secstrings + s->sh_name,
".init", 5) == 0)
continue;
s->sh_entsize = get_offset(&mod->core_size, s);
DEBUGP("\t%s\n", secstrings + s->sh_name);
}
if (m == 0)
mod->core_text_size = mod->core_size;
}
DEBUGP("Init section allocation order:\n");
for (m = 0; m < ARRAY_SIZE(masks); ++m) {
for (i = 0; i < hdr->e_shnum; ++i) {
Elf_Shdr *s = &sechdrs[i];
if ((s->sh_flags & masks[m][0]) != masks[m][0]
|| (s->sh_flags & masks[m][1])
|| s->sh_entsize != ~0UL
|| strncmp(secstrings + s->sh_name,
".init", 5) != 0)
continue;
s->sh_entsize = (get_offset(&mod->init_size, s)
| INIT_OFFSET_MASK);
DEBUGP("\t%s\n", secstrings + s->sh_name);
}
if (m == 0)
mod->init_text_size = mod->init_size;
}
}
static void set_license(struct module *mod, const char *license)
{
if (!license)
license = "unspecified";
if (!license_is_gpl_compatible(license)) {
if (!(tainted & TAINT_PROPRIETARY_MODULE))
printk(KERN_WARNING "%s: module license '%s' taints "
"kernel.\n", mod->name, license);
add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
}
}
/* 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;
}
static char *get_modinfo(Elf_Shdr *sechdrs,
unsigned int info,
const char *tag)
{
char *p;
unsigned int taglen = strlen(tag);
unsigned long size = sechdrs[info].sh_size;
for (p = (char *)sechdrs[info].sh_addr; p; p = next_string(p, &size)) {
if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
return p + taglen + 1;
}
return NULL;
}
static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
unsigned int infoindex)
{
struct module_attribute *attr;
int i;
for (i = 0; (attr = modinfo_attrs[i]); i++) {
if (attr->setup)
attr->setup(mod,
get_modinfo(sechdrs,
infoindex,
attr->attr.name));
}
}
#ifdef CONFIG_KALLSYMS
static int is_exported(const char *name, const struct module *mod)
{
if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
return 1;
else
if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
return 1;
else
return 0;
}
/* As per nm */
static char elf_type(const Elf_Sym *sym,
Elf_Shdr *sechdrs,
const char *secstrings,
struct module *mod)
{
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';
}
if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name,
".debug", strlen(".debug")) == 0)
return 'n';
return '?';
}
static void add_kallsyms(struct module *mod,
Elf_Shdr *sechdrs,
unsigned int symindex,
unsigned int strindex,
const char *secstrings)
{
unsigned int i;
mod->symtab = (void *)sechdrs[symindex].sh_addr;
mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
mod->strtab = (void *)sechdrs[strindex].sh_addr;
/* Set types up while we still have access to sections. */
for (i = 0; i < mod->num_symtab; i++)
mod->symtab[i].st_info
= elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
}
#else
static inline void add_kallsyms(struct module *mod,
Elf_Shdr *sechdrs,
unsigned int symindex,
unsigned int strindex,
const char *secstrings)
{
}
#endif /* CONFIG_KALLSYMS */
/* Allocate and load the module: note that size of section 0 is always
zero, and we rely on this for optional sections. */
static struct module *load_module(void __user *umod,
unsigned long len,
const char __user *uargs)
{
Elf_Ehdr *hdr;
Elf_Shdr *sechdrs;
char *secstrings, *args, *modmagic, *strtab = NULL;
unsigned int i;
unsigned int symindex = 0;
unsigned int strindex = 0;
unsigned int setupindex;
unsigned int exindex;
unsigned int exportindex;
unsigned int modindex;
unsigned int obsparmindex;
unsigned int infoindex;
unsigned int gplindex;
unsigned int crcindex;
unsigned int gplcrcindex;
unsigned int versindex;
unsigned int pcpuindex;
unsigned int gplfutureindex;
unsigned int gplfuturecrcindex;
unsigned int unwindex = 0;
unsigned int unusedindex;
unsigned int unusedcrcindex;
unsigned int unusedgplindex;
unsigned int unusedgplcrcindex;
struct module *mod;
long err = 0;
void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
struct exception_table_entry *extable;
mm_segment_t old_fs;
DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
umod, len, uargs);
if (len < sizeof(*hdr))
return ERR_PTR(-ENOEXEC);
/* Suck in entire file: we'll want most of it. */
/* vmalloc barfs on "unusual" numbers. Check here */
if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
return ERR_PTR(-ENOMEM);
if (copy_from_user(hdr, umod, len) != 0) {
err = -EFAULT;
goto free_hdr;
}
/* Sanity checks against insmoding binaries or wrong arch,
weird elf version */
if (memcmp(hdr->e_ident, ELFMAG, 4) != 0
|| hdr->e_type != ET_REL
|| !elf_check_arch(hdr)
|| hdr->e_shentsize != sizeof(*sechdrs)) {
err = -ENOEXEC;
goto free_hdr;
}
if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))
goto truncated;
/* Convenience variables */
sechdrs = (void *)hdr + hdr->e_shoff;
secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
sechdrs[0].sh_addr = 0;
for (i = 1; i < hdr->e_shnum; i++) {
if (sechdrs[i].sh_type != SHT_NOBITS
&& len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
goto truncated;
/* Mark all sections sh_addr with their address in the
temporary image. */
sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;
/* Internal symbols and strings. */
if (sechdrs[i].sh_type == SHT_SYMTAB) {
symindex = i;
strindex = sechdrs[i].sh_link;
strtab = (char *)hdr + sechdrs[strindex].sh_offset;
}
#ifndef CONFIG_MODULE_UNLOAD
/* Don't load .exit sections */
if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0)
sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
#endif
}
modindex = find_sec(hdr, sechdrs, secstrings,
".gnu.linkonce.this_module");
if (!modindex) {
printk(KERN_WARNING "No module found in object\n");
err = -ENOEXEC;
goto free_hdr;
}
mod = (void *)sechdrs[modindex].sh_addr;
if (symindex == 0) {
printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
mod->name);
err = -ENOEXEC;
goto free_hdr;
}
/* Optional sections */
exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future");
unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused");
unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl");
crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");
unusedcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused");
unusedgplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl");
setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
#ifdef ARCH_UNWIND_SECTION_NAME
unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME);
#endif
/* Don't keep modinfo section */
sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
#ifdef CONFIG_KALLSYMS
/* Keep symbol and string tables for decoding later. */
sechdrs[symindex].sh_flags |= SHF_ALLOC;
sechdrs[strindex].sh_flags |= SHF_ALLOC;
#endif
if (unwindex)
sechdrs[unwindex].sh_flags |= SHF_ALLOC;
/* Check module struct version now, before we try to use module. */
if (!check_modstruct_version(sechdrs, versindex, mod)) {
err = -ENOEXEC;
goto free_hdr;
}
modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
/* This is allowed: modprobe --force will invalidate it. */
if (!modmagic) {
add_taint_module(mod, TAINT_FORCED_MODULE);
printk(KERN_WARNING "%s: no version magic, tainting kernel.\n",
mod->name);
} else if (!same_magic(modmagic, vermagic)) {
printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
mod->name, modmagic, vermagic);
err = -ENOEXEC;
goto free_hdr;
}
/* Now copy in args */
args = strndup_user(uargs, ~0UL >> 1);
if (IS_ERR(args)) {
err = PTR_ERR(args);
goto free_hdr;
}
if (find_module(mod->name)) {
err = -EEXIST;
goto free_mod;
}
mod->state = MODULE_STATE_COMING;
/* Allow arches to frob section contents and sizes. */
err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod);
if (err < 0)
goto free_mod;
if (pcpuindex) {
/* We have a special allocation for this section. */
percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,
sechdrs[pcpuindex].sh_addralign,
mod->name);
if (!percpu) {
err = -ENOMEM;
goto free_mod;
}
sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
mod->percpu = percpu;
}
/* 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. */
layout_sections(mod, hdr, sechdrs, secstrings);
/* Do the allocs. */
ptr = module_alloc(mod->core_size);
if (!ptr) {
err = -ENOMEM;
goto free_percpu;
}
memset(ptr, 0, mod->core_size);
mod->module_core = ptr;
ptr = module_alloc(mod->init_size);
if (!ptr && mod->init_size) {
err = -ENOMEM;
goto free_core;
}
memset(ptr, 0, mod->init_size);
mod->module_init = ptr;
/* Transfer each section which specifies SHF_ALLOC */
DEBUGP("final section addresses:\n");
for (i = 0; i < hdr->e_shnum; i++) {
void *dest;
if (!(sechdrs[i].sh_flags & SHF_ALLOC))
continue;
if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK)
dest = mod->module_init
+ (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK);
else
dest = mod->module_core + sechdrs[i].sh_entsize;
if (sechdrs[i].sh_type != SHT_NOBITS)
memcpy(dest, (void *)sechdrs[i].sh_addr,
sechdrs[i].sh_size);
/* Update sh_addr to point to copy in image. */
sechdrs[i].sh_addr = (unsigned long)dest;
DEBUGP("\t0x%lx %s\n", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
}
/* Module has been moved. */
mod = (void *)sechdrs[modindex].sh_addr;
/* Now we've moved module, initialize linked lists, etc. */
module_unload_init(mod);
/* Initialize kobject, so we can reference it. */
if (mod_sysfs_init(mod) != 0)
goto cleanup;
/* Set up license info based on the info section */
set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
if (strcmp(mod->name, "ndiswrapper") == 0)
add_taint(TAINT_PROPRIETARY_MODULE);
if (strcmp(mod->name, "driverloader") == 0)
add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
/* Set up MODINFO_ATTR fields */
setup_modinfo(mod, sechdrs, infoindex);
/* Fix up syms, so that st_value is a pointer to location. */
err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
mod);
if (err < 0)
goto cleanup;
/* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */
mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms);
mod->syms = (void *)sechdrs[exportindex].sh_addr;
if (crcindex)
mod->crcs = (void *)sechdrs[crcindex].sh_addr;
mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms);
mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr;
if (gplcrcindex)
mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;
mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size /
sizeof(*mod->gpl_future_syms);
mod->num_unused_syms = sechdrs[unusedindex].sh_size /
sizeof(*mod->unused_syms);
mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size /
sizeof(*mod->unused_gpl_syms);
mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;
if (gplfuturecrcindex)
mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;
mod->unused_syms = (void *)sechdrs[unusedindex].sh_addr;
if (unusedcrcindex)
mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr;
mod->unused_gpl_syms = (void *)sechdrs[unusedgplindex].sh_addr;
if (unusedgplcrcindex)
mod->unused_crcs = (void *)sechdrs[unusedgplcrcindex].sh_addr;
#ifdef CONFIG_MODVERSIONS
if ((mod->num_syms && !crcindex) ||
(mod->num_gpl_syms && !gplcrcindex) ||
(mod->num_gpl_future_syms && !gplfuturecrcindex) ||
(mod->num_unused_syms && !unusedcrcindex) ||
(mod->num_unused_gpl_syms && !unusedgplcrcindex)) {
printk(KERN_WARNING "%s: No versions for exported symbols."
" Tainting kernel.\n", mod->name);
add_taint_module(mod, TAINT_FORCED_MODULE);
}
#endif
/* Now do relocations. */
for (i = 1; i < hdr->e_shnum; i++) {
const char *strtab = (char *)sechdrs[strindex].sh_addr;
unsigned int info = sechdrs[i].sh_info;
/* Not a valid relocation section? */
if (info >= hdr->e_shnum)
continue;
/* Don't bother with non-allocated sections */
if (!(sechdrs[info].sh_flags & SHF_ALLOC))
continue;
if (sechdrs[i].sh_type == SHT_REL)
err = apply_relocate(sechdrs, strtab, symindex, i,mod);
else if (sechdrs[i].sh_type == SHT_RELA)
err = apply_relocate_add(sechdrs, strtab, symindex, i,
mod);
if (err < 0)
goto cleanup;
}
/* Find duplicate symbols */
err = verify_export_symbols(mod);
if (err < 0)
goto cleanup;
/* Set up and sort exception table */
mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable);
mod->extable = extable = (void *)sechdrs[exindex].sh_addr;
sort_extable(extable, extable + mod->num_exentries);
/* Finally, copy percpu area over. */
percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
sechdrs[pcpuindex].sh_size);
add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
err = module_finalize(hdr, sechdrs, mod);
if (err < 0)
goto cleanup;
/* 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);
mod->args = args;
if (obsparmindex)
printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
mod->name);
/* Size of section 0 is 0, so this works well if no params */
err = parse_args(mod->name, mod->args,
(struct kernel_param *)
sechdrs[setupindex].sh_addr,
sechdrs[setupindex].sh_size
/ sizeof(struct kernel_param),
NULL);
if (err < 0)
goto arch_cleanup;
err = mod_sysfs_setup(mod,
(struct kernel_param *)
sechdrs[setupindex].sh_addr,
sechdrs[setupindex].sh_size
/ sizeof(struct kernel_param));
if (err < 0)
goto arch_cleanup;
add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
/* Size of section 0 is 0, so this works well if no unwind info. */
mod->unwind_info = unwind_add_table(mod,
(void *)sechdrs[unwindex].sh_addr,
sechdrs[unwindex].sh_size);
/* Get rid of temporary copy */
vfree(hdr);
/* Done! */
return mod;
arch_cleanup:
module_arch_cleanup(mod);
cleanup:
module_unload_free(mod);
module_free(mod, mod->module_init);
free_core:
module_free(mod, mod->module_core);
free_percpu:
if (percpu)
percpu_modfree(percpu);
free_mod:
kfree(args);
free_hdr:
vfree(hdr);
return ERR_PTR(err);
truncated:
printk(KERN_ERR "Module len %lu truncated\n", len);
err = -ENOEXEC;
goto free_hdr;
}
/*
* link the module with the whole machine is stopped with interrupts off
* - this defends against kallsyms not taking locks
*/
static int __link_module(void *_mod)
{
struct module *mod = _mod;
list_add(&mod->list, &modules);
return 0;
}
/* This is where the real work happens */
asmlinkage long
sys_init_module(void __user *umod,
unsigned long len,
const char __user *uargs)
{
struct module *mod;
int ret = 0;
/* Must have permission */
if (!capable(CAP_SYS_MODULE))
return -EPERM;
/* Only one module load at a time, please */
if (mutex_lock_interruptible(&module_mutex) != 0)
return -EINTR;
/* Do all the hard work */
mod = load_module(umod, len, uargs);
if (IS_ERR(mod)) {
mutex_unlock(&module_mutex);
return PTR_ERR(mod);
}
/* Now sew it into the lists. They won't access us, since
strong_try_module_get() will fail. */
stop_machine_run(__link_module, mod, NR_CPUS);
/* Drop lock so they can recurse */
mutex_unlock(&module_mutex);
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_COMING, mod);
/* Start the module */
if (mod->init != NULL)
ret = mod->init();
if (ret < 0) {
/* Init routine failed: abort. Try to protect us from
buggy refcounters. */
mod->state = MODULE_STATE_GOING;
synchronize_sched();
if (mod->unsafe)
printk(KERN_ERR "%s: module is now stuck!\n",
mod->name);
else {
module_put(mod);
mutex_lock(&module_mutex);
free_module(mod);
mutex_unlock(&module_mutex);
}
return ret;
}
/* Now it's a first class citizen! */
mutex_lock(&module_mutex);
mod->state = MODULE_STATE_LIVE;
/* Drop initial reference. */
module_put(mod);
unwind_remove_table(mod->unwind_info, 1);
module_free(mod, mod->module_init);
mod->module_init = NULL;
mod->init_size = 0;
mod->init_text_size = 0;
mutex_unlock(&module_mutex);
return 0;
}
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 $d.
*/
static inline int is_arm_mapping_symbol(const char *str)
{
return str[0] == '$' && strchr("atd", str[1])
&& (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 */
if (within(addr, mod->module_init, mod->init_size))
nextval = (unsigned long)mod->module_init+mod->init_text_size;
else
nextval = (unsigned long)mod->module_core+mod->core_text_size;
/* Scan for closest preceeding symbol, and next symbol. (ELF
starts real symbols at 1). */
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;
if (size)
*size = nextval - mod->symtab[best].st_value;
if (offset)
*offset = addr - mod->symtab[best].st_value;
return mod->strtab + mod->symtab[best].st_name;
}
/* For kallsyms to ask for address resolution. NULL means not found.
We don't lock, as this is used for oops resolution and races are a
lesser concern. */
const char *module_address_lookup(unsigned long addr,
unsigned long *size,
unsigned long *offset,
char **modname)
{
struct module *mod;
list_for_each_entry(mod, &modules, list) {
if (within(addr, mod->module_init, mod->init_size)
|| within(addr, mod->module_core, mod->core_size)) {
if (modname)
*modname = mod->name;
return get_ksymbol(mod, addr, size, offset);
}
}
return NULL;
}
int lookup_module_symbol_name(unsigned long addr, char *symname)
{
struct module *mod;
mutex_lock(&module_mutex);
list_for_each_entry(mod, &modules, list) {
if (within(addr, mod->module_init, mod->init_size) ||
within(addr, mod->module_core, mod->core_size)) {
const char *sym;
sym = get_ksymbol(mod, addr, NULL, NULL);
if (!sym)
goto out;
strlcpy(symname, sym, KSYM_NAME_LEN);
mutex_unlock(&module_mutex);
return 0;
}
}
out:
mutex_unlock(&module_mutex);
return -ERANGE;
}
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
unsigned long *offset, char *modname, char *name)
{
struct module *mod;
mutex_lock(&module_mutex);
list_for_each_entry(mod, &modules, list) {
if (within(addr, mod->module_init, mod->init_size) ||
within(addr, mod->module_core, mod->core_size)) {
const char *sym;
sym = get_ksymbol(mod, addr, size, offset);
if (!sym)
goto out;
if (modname)
strlcpy(modname, mod->name, MODULE_NAME_LEN);
if (name)
strlcpy(name, sym, KSYM_NAME_LEN);
mutex_unlock(&module_mutex);
return 0;
}
}
out:
mutex_unlock(&module_mutex);
return -ERANGE;
}
int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
char *name, char *module_name, int *exported)
{
struct module *mod;
mutex_lock(&module_mutex);
list_for_each_entry(mod, &modules, list) {
if (symnum < mod->num_symtab) {
*value = mod->symtab[symnum].st_value;
*type = mod->symtab[symnum].st_info;
strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
KSYM_NAME_LEN);
strlcpy(module_name, mod->name, MODULE_NAME_LEN);
*exported = is_exported(name, mod);
mutex_unlock(&module_mutex);
return 0;
}
symnum -= mod->num_symtab;
}
mutex_unlock(&module_mutex);
return -ERANGE;
}
static unsigned long mod_find_symname(struct module *mod, const char *name)
{
unsigned int i;
for (i = 0; i < mod->num_symtab; i++)
if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
mod->symtab[i].st_info != 'U')
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. */
if ((colon = strchr(name, ':')) != NULL) {
*colon = '\0';
if ((mod = find_module(name)) != NULL)
ret = mod_find_symname(mod, colon+1);
*colon = ':';
} else {
list_for_each_entry(mod, &modules, list)
if ((ret = mod_find_symname(mod, name)) != 0)
break;
}
return ret;
}
#endif /* CONFIG_KALLSYMS */
/* 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);
}
static char *taint_flags(unsigned int taints, char *buf)
{
int bx = 0;
if (taints) {
buf[bx++] = '(';
if (taints & TAINT_PROPRIETARY_MODULE)
buf[bx++] = 'P';
if (taints & TAINT_FORCED_MODULE)
buf[bx++] = 'F';
/*
* TAINT_FORCED_RMMOD: could be added.
* TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
* apply to modules.
*/
buf[bx++] = ')';
}
buf[bx] = '\0';
return buf;
}
static int m_show(struct seq_file *m, void *p)
{
struct module *mod = list_entry(p, struct module, list);
char buf[8];
seq_printf(m, "%s %lu",
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. */
seq_printf(m, " 0x%p", mod->module_core);
/* Taints info */
if (mod->taints)
seq_printf(m, " %s", taint_flags(mod->taints, buf));
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 -.
*/
const struct seq_operations modules_op = {
.start = m_start,
.next = m_next,
.stop = m_stop,
.show = m_show
};
/* 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;
preempt_disable();
list_for_each_entry(mod, &modules, list) {
if (mod->num_exentries == 0)
continue;
e = search_extable(mod->extable,
mod->extable + mod->num_exentries - 1,
addr);
if (e)
break;
}
preempt_enable();
/* Now, if we found one, we are running inside it now, hence
we cannot unload the module, hence no refcnt needed. */
return e;
}
/*
* Is this a valid module address?
*/
int is_module_address(unsigned long addr)
{
struct module *mod;
preempt_disable();
list_for_each_entry(mod, &modules, list) {
if (within(addr, mod->module_core, mod->core_size)) {
preempt_enable();
return 1;
}
}
preempt_enable();
return 0;
}
/* Is this a valid kernel address? */
struct module *__module_text_address(unsigned long addr)
{
struct module *mod;
list_for_each_entry(mod, &modules, list)
if (within(addr, mod->module_init, mod->init_text_size)
|| within(addr, mod->module_core, mod->core_text_size))
return mod;
return NULL;
}
struct module *module_text_address(unsigned long addr)
{
struct module *mod;
preempt_disable();
mod = __module_text_address(addr);
preempt_enable();
return mod;
}
/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
struct module *mod;
char buf[8];
printk("Modules linked in:");
list_for_each_entry(mod, &modules, list)
printk(" %s%s", mod->name, taint_flags(mod->taints, buf));
printk("\n");
}
#ifdef CONFIG_SYSFS
static char *make_driver_name(struct device_driver *drv)
{
char *driver_name;
driver_name = kmalloc(strlen(drv->name) + strlen(drv->bus->name) + 2,
GFP_KERNEL);
if (!driver_name)
return NULL;
sprintf(driver_name, "%s:%s", drv->bus->name, drv->name);
return driver_name;
}
static void module_create_drivers_dir(struct module_kobject *mk)
{
if (!mk || mk->drivers_dir)
return;
mk->drivers_dir = kobject_add_dir(&mk->kobj, "drivers");
}
void module_add_driver(struct module *mod, struct device_driver *drv)
{
char *driver_name;
int no_warn;
struct module_kobject *mk = NULL;
if (!drv)
return;
if (mod)
mk = &mod->mkobj;
else if (drv->mod_name) {
struct kobject *mkobj;
/* Lookup built-in module entry in /sys/modules */
mkobj = kset_find_obj(&module_subsys, drv->mod_name);
if (mkobj) {
mk = container_of(mkobj, struct module_kobject, kobj);
/* remember our module structure */
drv->mkobj = mk;
/* kset_find_obj took a reference */
kobject_put(mkobj);
}
}
if (!mk)
return;
/* Don't check return codes; these calls are idempotent */
no_warn = sysfs_create_link(&drv->kobj, &mk->kobj, "module");
driver_name = make_driver_name(drv);
if (driver_name) {
module_create_drivers_dir(mk);
no_warn = sysfs_create_link(mk->drivers_dir, &drv->kobj,
driver_name);
kfree(driver_name);
}
}
EXPORT_SYMBOL(module_add_driver);
void module_remove_driver(struct device_driver *drv)
{
struct module_kobject *mk = NULL;
char *driver_name;
if (!drv)
return;
sysfs_remove_link(&drv->kobj, "module");
if (drv->owner)
mk = &drv->owner->mkobj;
else if (drv->mkobj)
mk = drv->mkobj;
if (mk && mk->drivers_dir) {
driver_name = make_driver_name(drv);
if (driver_name) {
sysfs_remove_link(mk->drivers_dir, driver_name);
kfree(driver_name);
}
}
}
EXPORT_SYMBOL(module_remove_driver);
#endif
#ifdef CONFIG_MODVERSIONS
/* Generate the signature for struct module here, too, for modversions. */
void struct_module(struct module *mod) { return; }
EXPORT_SYMBOL(struct_module);
#endif
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