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linux/kernel/module.c
Greg Kroah-Hartman 03e88ae1b1 [PATCH] fix module sysfs files reference counting 
The module files, refcnt, version, and srcversion did not properly
increment the owner's module reference count, allowing the modules to
be removed while the files were open, causing oopses.

This patch fixes this, and also fixes the problem that the version and
srcversion files were not showing up, unless CONFIG_MODULE_UNLOAD was
enabled, which is not correct.

Cc: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-03-20 13:42:58 -08:00

2309 lines
59 KiB
C
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/* Rewritten by Rusty Russell, on the backs of many others...
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/config.h>
#include <linux/module.h>
#include <linux/moduleloader.h>
#include <linux/init.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/stop_machine.h>
#include <linux/device.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <asm/uaccess.h>
#include <asm/semaphore.h>
#include <asm/cacheflush.h>
#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))
/* Protects module list */
static DEFINE_SPINLOCK(modlist_lock);
/* List of modules, protected by module_mutex AND modlist_lock */
static DECLARE_MUTEX(module_mutex);
static LIST_HEAD(modules);
static DECLARE_MUTEX(notify_mutex);
static struct notifier_block * module_notify_list;
int register_module_notifier(struct notifier_block * nb)
{
int err;
down(&notify_mutex);
err = notifier_chain_register(&module_notify_list, nb);
up(&notify_mutex);
return err;
}
EXPORT_SYMBOL(register_module_notifier);
int unregister_module_notifier(struct notifier_block * nb)
{
int err;
down(&notify_mutex);
err = notifier_chain_unregister(&module_notify_list, nb);
up(&notify_mutex);
return err;
}
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);
}
/* A thread that wants to hold a reference to a module only while it
* is running can call ths 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 unsigned long __start___kcrctab[];
extern const unsigned long __start___kcrctab_gpl[];
extern const unsigned long __start___kcrctab_gpl_future[];
#ifndef CONFIG_MODVERSIONS
#define symversion(base, idx) NULL
#else
#define symversion(base, idx) ((base) ? ((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;
}
/* 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;
}
/* 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->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;
}
/* Find a symbol in this elf symbol table */
static unsigned long find_local_symbol(Elf_Shdr *sechdrs,
unsigned int symindex,
const char *strtab,
const char *name)
{
unsigned int i;
Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
/* Search (defined) internal symbols first. */
for (i = 1; i < sechdrs[symindex].sh_size/sizeof(*sym); i++) {
if (sym[i].st_shndx != SHN_UNDEF
&& strcmp(name, strtab + sym[i].st_name) == 0)
return sym[i].st_value;
}
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 = kmalloc(sizeof(new[0]) * pcpu_num_allocated*2,
GFP_KERNEL);
if (!new)
return 0;
memcpy(new, pcpu_size, sizeof(new[0])*pcpu_num_allocated);
pcpu_num_allocated *= 2;
kfree(pcpu_size);
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 > SMP_CACHE_BYTES) {
printk(KERN_WARNING "%s: per-cpu alignment %li > %i\n",
name, align, SMP_CACHE_BYTES);
align = SMP_CACHE_BYTES;
}
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] = -ALIGN(__per_cpu_end-__per_cpu_start, SMP_CACHE_BYTES);
/* 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, \
.owner = THIS_MODULE }, \
.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;
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);
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);
/* 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 */
up(&module_mutex);
for (;;) {
DEBUGP("Looking at refcount...\n");
set_current_state(TASK_UNINTERRUPTIBLE);
if (module_refcount(mod) == 0)
break;
schedule();
}
current->state = TASK_RUNNING;
down(&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 (down_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) {
up(&module_mutex);
mod->exit();
down(&module_mutex);
}
free_module(mod);
out:
up(&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;
unsigned long flags;
const unsigned long *crc;
spin_lock_irqsave(&modlist_lock, flags);
if (!__find_symbol(symbol, &owner, &crc, 1))
BUG();
module_put(owner);
spin_unlock_irqrestore(&modlist_lock, flags);
}
EXPORT_SYMBOL(__symbol_put);
void symbol_put_addr(void *addr)
{
unsigned long flags;
spin_lock_irqsave(&modlist_lock, flags);
if (!kernel_text_address((unsigned long)addr))
BUG();
module_put(module_text_address((unsigned long)addr));
spin_unlock_irqrestore(&modlist_lock, flags);
}
EXPORT_SYMBOL_GPL(symbol_put_addr);
static ssize_t show_refcnt(struct module_attribute *mattr,
struct module *mod, char *buffer)
{
/* sysfs holds a reference */
return sprintf(buffer, "%u\n", module_refcount(mod)-1);
}
static struct module_attribute refcnt = {
.attr = { .name = "refcnt", .mode = 0444, .owner = THIS_MODULE },
.show = show_refcnt,
};
#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 struct module_attribute *modinfo_attrs[] = {
&modinfo_version,
&modinfo_srcversion,
#ifdef CONFIG_MODULE_UNLOAD
&refcnt,
#endif
NULL,
};
#ifdef CONFIG_OBSOLETE_MODPARM
/* Bounds checking done below */
static int obsparm_copy_string(const char *val, struct kernel_param *kp)
{
strcpy(kp->arg, val);
return 0;
}
static int set_obsolete(const char *val, struct kernel_param *kp)
{
unsigned int min, max;
unsigned int size, maxsize;
int dummy;
char *endp;
const char *p;
struct obsolete_modparm *obsparm = kp->arg;
if (!val) {
printk(KERN_ERR "Parameter %s needs an argument\n", kp->name);
return -EINVAL;
}
/* type is: [min[-max]]{b,h,i,l,s} */
p = obsparm->type;
min = simple_strtol(p, &endp, 10);
if (endp == obsparm->type)
min = max = 1;
else if (*endp == '-') {
p = endp+1;
max = simple_strtol(p, &endp, 10);
} else
max = min;
switch (*endp) {
case 'b':
return param_array(kp->name, val, min, max, obsparm->addr,
1, param_set_byte, &dummy);
case 'h':
return param_array(kp->name, val, min, max, obsparm->addr,
sizeof(short), param_set_short, &dummy);
case 'i':
return param_array(kp->name, val, min, max, obsparm->addr,
sizeof(int), param_set_int, &dummy);
case 'l':
return param_array(kp->name, val, min, max, obsparm->addr,
sizeof(long), param_set_long, &dummy);
case 's':
return param_array(kp->name, val, min, max, obsparm->addr,
sizeof(char *), param_set_charp, &dummy);
case 'c':
/* Undocumented: 1-5c50 means 1-5 strings of up to 49 chars,
and the decl is "char xxx[5][50];" */
p = endp+1;
maxsize = simple_strtol(p, &endp, 10);
/* We check lengths here (yes, this is a hack). */
p = val;
while (p[size = strcspn(p, ",")]) {
if (size >= maxsize)
goto oversize;
p += size+1;
}
if (size >= maxsize)
goto oversize;
return param_array(kp->name, val, min, max, obsparm->addr,
maxsize, obsparm_copy_string, &dummy);
}
printk(KERN_ERR "Unknown obsolete parameter type %s\n", obsparm->type);
return -EINVAL;
oversize:
printk(KERN_ERR
"Parameter %s doesn't fit in %u chars.\n", kp->name, maxsize);
return -EINVAL;
}
static int obsolete_params(const char *name,
char *args,
struct obsolete_modparm obsparm[],
unsigned int num,
Elf_Shdr *sechdrs,
unsigned int symindex,
const char *strtab)
{
struct kernel_param *kp;
unsigned int i;
int ret;
kp = kmalloc(sizeof(kp[0]) * num, GFP_KERNEL);
if (!kp)
return -ENOMEM;
for (i = 0; i < num; i++) {
char sym_name[128 + sizeof(MODULE_SYMBOL_PREFIX)];
snprintf(sym_name, sizeof(sym_name), "%s%s",
MODULE_SYMBOL_PREFIX, obsparm[i].name);
kp[i].name = obsparm[i].name;
kp[i].perm = 000;
kp[i].set = set_obsolete;
kp[i].get = NULL;
obsparm[i].addr
= (void *)find_local_symbol(sechdrs, symindex, strtab,
sym_name);
if (!obsparm[i].addr) {
printk("%s: falsely claims to have parameter %s\n",
name, obsparm[i].name);
ret = -EINVAL;
goto out;
}
kp[i].arg = &obsparm[i];
}
ret = parse_args(name, args, kp, num, NULL);
out:
kfree(kp);
return ret;
}
#else
static int obsolete_params(const char *name,
char *args,
struct obsolete_modparm obsparm[],
unsigned int num,
Elf_Shdr *sechdrs,
unsigned int symindex,
const char *strtab)
{
if (num != 0)
printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
name);
return 0;
}
#endif /* CONFIG_OBSOLETE_MODPARM */
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(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->license_gplok);
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 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]);
if (! (sect_attrs = kmalloc(size[0] + size[1], GFP_KERNEL)))
return;
/* Setup section attributes. */
sect_attrs->grp.name = "sections";
sect_attrs->grp.attrs = (void *)sect_attrs + size[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;
strlcpy(sattr->name, secstrings + sechdrs[i].sh_name,
MODULE_SECT_NAME_LEN);
sattr->mattr.show = module_sect_show;
sattr->mattr.store = NULL;
sattr->mattr.attr.name = sattr->name;
sattr->mattr.attr.owner = mod;
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:
kfree(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. */
kfree(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 */
static 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));
temp_attr->attr.owner = mod;
error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
++temp_attr;
}
}
return error;
}
static 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);
}
static int mod_sysfs_setup(struct module *mod,
struct kernel_param *kparam,
unsigned int num_params)
{
int err;
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;
err = kobject_register(&mod->mkobj.kobj);
if (err)
goto out;
err = module_param_sysfs_setup(mod, kparam, num_params);
if (err)
goto out_unreg;
err = module_add_modinfo_attrs(mod);
if (err)
goto out_unreg;
return 0;
out_unreg:
kobject_unregister(&mod->mkobj.kobj);
out:
return err;
}
static void mod_kobject_remove(struct module *mod)
{
module_remove_modinfo_attrs(mod);
module_param_sysfs_remove(mod);
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);
/* 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);
/* 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, flags;
const unsigned long *crc;
spin_lock_irqsave(&modlist_lock, flags);
value = __find_symbol(symbol, &owner, &crc, 1);
if (value && !strong_try_module_get(owner))
value = 0;
spin_unlock_irqrestore(&modlist_lock, flags);
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 modules 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 inline int license_is_gpl_compatible(const char *license)
{
return (strcmp(license, "GPL") == 0
|| strcmp(license, "GPL v2") == 0
|| strcmp(license, "GPL and additional rights") == 0
|| strcmp(license, "Dual BSD/GPL") == 0
|| strcmp(license, "Dual MPL/GPL") == 0);
}
static void set_license(struct module *mod, const char *license)
{
if (!license)
license = "unspecified";
mod->license_gplok = license_is_gpl_compatible(license);
if (!mod->license_gplok && !(tainted & TAINT_PROPRIETARY_MODULE)) {
printk(KERN_WARNING "%s: module license '%s' taints kernel.\n",
mod->name, license);
add_taint(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
int is_exported(const char *name, const struct module *mod)
{
if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
return 1;
else
if (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, symindex = 0, strindex = 0, setupindex, exindex,
exportindex, modindex, obsparmindex, infoindex, gplindex,
crcindex, gplcrcindex, versindex, pcpuindex, gplfutureindex,
gplfuturecrcindex;
long arglen;
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");
crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");
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);
/* 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
/* 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(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 */
arglen = strlen_user(uargs);
if (!arglen) {
err = -EFAULT;
goto free_hdr;
}
args = kmalloc(arglen, GFP_KERNEL);
if (!args) {
err = -ENOMEM;
goto free_hdr;
}
if (copy_from_user(args, uargs, arglen) != 0) {
err = -EFAULT;
goto free_mod;
}
/* Userspace could have altered the string after the strlen_user() */
args[arglen - 1] = '\0';
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);
/* 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(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->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;
if (gplfuturecrcindex)
mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;
#ifdef CONFIG_MODVERSIONS
if ((mod->num_syms && !crcindex) ||
(mod->num_gpl_syms && !gplcrcindex) ||
(mod->num_gpl_future_syms && !gplfuturecrcindex)) {
printk(KERN_WARNING "%s: No versions for exported symbols."
" Tainting kernel.\n", mod->name);
add_taint(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) {
err = obsolete_params(mod->name, mod->args,
(struct obsolete_modparm *)
sechdrs[obsparmindex].sh_addr,
sechdrs[obsparmindex].sh_size
/ sizeof(struct obsolete_modparm),
sechdrs, symindex,
(char *)sechdrs[strindex].sh_addr);
if (setupindex)
printk(KERN_WARNING "%s: Ignoring new-style "
"parameters in presence of obsolete ones\n",
mod->name);
} else {
/* 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);
/* 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 (down_interruptible(&module_mutex) != 0)
return -EINTR;
/* Do all the hard work */
mod = load_module(umod, len, uargs);
if (IS_ERR(mod)) {
up(&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 */
up(&module_mutex);
down(&notify_mutex);
notifier_call_chain(&module_notify_list, MODULE_STATE_COMING, mod);
up(&notify_mutex);
/* 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);
down(&module_mutex);
free_module(mod);
up(&module_mutex);
}
return ret;
}
/* Now it's a first class citizen! */
down(&module_mutex);
mod->state = MODULE_STATE_LIVE;
/* Drop initial reference. */
module_put(mod);
module_free(mod, mod->module_init);
mod->module_init = NULL;
mod->init_size = 0;
mod->init_text_size = 0;
up(&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;
*size = nextval - mod->symtab[best].st_value;
*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)) {
*modname = mod->name;
return get_ksymbol(mod, addr, size, offset);
}
}
return NULL;
}
struct module *module_get_kallsym(unsigned int symnum,
unsigned long *value,
char *type,
char namebuf[128])
{
struct module *mod;
down(&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;
strncpy(namebuf,
mod->strtab + mod->symtab[symnum].st_name,
127);
up(&module_mutex);
return mod;
}
symnum -= mod->num_symtab;
}
up(&module_mutex);
return NULL;
}
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)
{
struct list_head *i;
loff_t n = 0;
down(&module_mutex);
list_for_each(i, &modules) {
if (n++ == *pos)
break;
}
if (i == &modules)
return NULL;
return i;
}
static void *m_next(struct seq_file *m, void *p, loff_t *pos)
{
struct list_head *i = p;
(*pos)++;
if (i->next == &modules)
return NULL;
return i->next;
}
static void m_stop(struct seq_file *m, void *p)
{
up(&module_mutex);
}
static int m_show(struct seq_file *m, void *p)
{
struct module *mod = list_entry(p, struct module, list);
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);
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 -.
*/
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)
{
unsigned long flags;
const struct exception_table_entry *e = NULL;
struct module *mod;
spin_lock_irqsave(&modlist_lock, flags);
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;
}
spin_unlock_irqrestore(&modlist_lock, flags);
/* 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 kernel address? We don't grab the lock: we are oopsing. */
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;
unsigned long flags;
spin_lock_irqsave(&modlist_lock, flags);
mod = __module_text_address(addr);
spin_unlock_irqrestore(&modlist_lock, flags);
return mod;
}
/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
struct module *mod;
printk("Modules linked in:");
list_for_each_entry(mod, &modules, list)
printk(" %s", mod->name);
printk("\n");
}
void module_add_driver(struct module *mod, struct device_driver *drv)
{
if (!mod || !drv)
return;
/* Don't check return code; this call is idempotent */
sysfs_create_link(&drv->kobj, &mod->mkobj.kobj, "module");
}
EXPORT_SYMBOL(module_add_driver);
void module_remove_driver(struct device_driver *drv)
{
if (!drv)
return;
sysfs_remove_link(&drv->kobj, "module");
}
EXPORT_SYMBOL(module_remove_driver);
#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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