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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/kernel/module.c

2109 строки
53 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/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/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 <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 unsigned long __start___kcrctab[];
extern const unsigned long __start___kcrctab_gpl[];
#ifndef CONFIG_MODVERSIONS
#define symversion(base, idx) NULL
#else
#define symversion(base, idx) ((base) ? ((base) + (idx)) : NULL)
#endif
/* 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;
unsigned int i;
/* Core kernel first. */
*owner = NULL;
for (i = 0; __start___ksymtab+i < __stop___ksymtab; i++) {
if (strcmp(__start___ksymtab[i].name, name) == 0) {
*crc = symversion(__start___kcrctab, i);
return __start___ksymtab[i].value;
}
}
if (gplok) {
for (i = 0; __start___ksymtab_gpl+i<__stop___ksymtab_gpl; i++)
if (strcmp(__start___ksymtab_gpl[i].name, name) == 0) {
*crc = symversion(__start___kcrctab_gpl, i);
return __start___ksymtab_gpl[i].value;
}
}
/* Now try modules. */
list_for_each_entry(mod, &modules, list) {
*owner = mod;
for (i = 0; i < mod->num_syms; i++)
if (strcmp(mod->syms[i].name, name) == 0) {
*crc = symversion(mod->crcs, i);
return mod->syms[i].value;
}
if (gplok) {
for (i = 0; i < mod->num_gpl_syms; i++) {
if (strcmp(mod->gpl_syms[i].name, name) == 0) {
*crc = symversion(mod->gpl_crcs, i);
return mod->gpl_syms[i].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)
{
unsigned long extra;
unsigned int i;
void *ptr;
BUG_ON(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)
{
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 */
#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[_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(unsigned int flags)
{
int ret = (flags & O_TRUNC);
if (ret)
tainted |= TAINT_FORCED_MODULE;
return ret;
}
#else
static inline int try_force(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(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(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 */
#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;
}
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);
tainted |= 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;
spin_lock_irq(&modlist_lock);
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;
}
spin_unlock_irq(&modlist_lock);
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 */
#ifdef CONFIG_MODULE_UNLOAD
static inline int module_add_refcnt_attr(struct module *mod)
{
return sysfs_create_file(&mod->mkobj.kobj, &refcnt.attr);
}
static void module_remove_refcnt_attr(struct module *mod)
{
return sysfs_remove_file(&mod->mkobj.kobj, &refcnt.attr);
}
#else
static inline int module_add_refcnt_attr(struct module *mod)
{
return 0;
}
static void module_remove_refcnt_attr(struct module *mod)
{
}
#endif
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_add_refcnt_attr(mod);
if (err)
goto out_unreg;
err = module_param_sysfs_setup(mod, kparam, num_params);
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_refcnt_attr(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);
/* 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);
tainted |= 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;
}
#ifdef CONFIG_KALLSYMS
int is_exported(const char *name, const struct module *mod)
{
unsigned int i;
if (!mod) {
for (i = 0; __start___ksymtab+i < __stop___ksymtab; i++)
if (strcmp(__start___ksymtab[i].name, name) == 0)
return 1;
return 0;
}
for (i = 0; i < mod->num_syms; i++)
if (strcmp(mod->syms[i].name, name) == 0)
return 1;
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;
long arglen;
struct module *mod;
long err = 0;
void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
struct exception_table_entry *extable;
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");
crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_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);
/* 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) {
tainted |= 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;
}
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);
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"));
/* 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;
#ifdef CONFIG_MODVERSIONS
if ((mod->num_syms && !crcindex) ||
(mod->num_gpl_syms && !gplcrcindex)) {
printk(KERN_WARNING "%s: No versions for exported symbols."
" Tainting kernel.\n", mod->name);
tainted |= 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;
}
/* 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;
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);
if (err < 0) return ERR_PTR(err);
else return ptr;
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);
}
/* Flush the instruction cache, since we've played with text */
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);
/* 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_kernel();
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)
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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