/* If this is set, the section belongs in the init part of the module */
#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
-/* List of modules, protected by module_mutex or preempt_disable
+/*
+ * Mutex protects:
+ * 1) List of modules (also safely readable with preempt_disable),
+ * 2) module_use links,
+ * 3) module_addr_min/module_addr_max.
* (delete uses stop_machine/add uses RCU list operations). */
DEFINE_MUTEX(module_mutex);
EXPORT_SYMBOL_GPL(module_mutex);
static BLOCKING_NOTIFIER_HEAD(module_notify_list);
-/* Bounds of module allocation, for speeding __module_address */
+/* Bounds of module allocation, for speeding __module_address.
+ * Protected by module_mutex. */
static unsigned long module_addr_min = -1UL, module_addr_max = 0;
int register_module_notifier(struct notifier_block * nb)
}
/* Find a symbol and return it, along with, (optional) crc and
- * (optional) module which owns it */
+ * (optional) module which owns it. Needs preempt disabled or module_mutex. */
const struct kernel_symbol *find_symbol(const char *name,
struct module **owner,
const unsigned long **crc,
mod->waiter = current;
}
-/* modules using other modules */
-struct module_use
-{
- struct list_head source_list;
- struct list_head target_list;
- struct module *source, *target;
-};
-
/* Does a already use b? */
static int already_uses(struct module *a, struct module *b)
{
*/
static int add_module_usage(struct module *a, struct module *b)
{
- int no_warn;
struct module_use *use;
DEBUGP("Allocating new usage for %s.\n", a->name);
use->target = b;
list_add(&use->source_list, &b->source_list);
list_add(&use->target_list, &a->target_list);
- no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name);
return 0;
}
-/* Module a uses b */
+/* Module a uses b: caller needs module_mutex() */
int use_module(struct module *a, struct module *b)
{
- struct module_use *use;
- int no_warn, err;
+ int err;
if (b == NULL || already_uses(a, b)) return 1;
{
struct module_use *use, *tmp;
+ mutex_lock(&module_mutex);
list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
struct module *i = use->target;
DEBUGP("%s unusing %s\n", mod->name, i->name);
list_del(&use->source_list);
list_del(&use->target_list);
kfree(use);
- sysfs_remove_link(i->holders_dir, mod->name);
}
+ mutex_unlock(&module_mutex);
}
#ifdef CONFIG_MODULE_FORCE_UNLOAD
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_GOING, mod);
async_synchronize_full();
- mutex_lock(&module_mutex);
+
/* Store the name of the last unloaded module for diagnostic purposes */
strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
ddebug_remove_module(mod->name);
- free_module(mod);
- out:
+ free_module(mod);
+ return 0;
+out:
mutex_unlock(&module_mutex);
return ret;
}
{
const unsigned long *crc;
+ /* Since this should be found in kernel (which can't be removed),
+ * no locking is necessary. */
if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
&crc, true, false))
BUG();
}
#endif /* CONFIG_MODVERSIONS */
-/* Resolve a symbol for this module. I.e. if we find one, record usage.
- Must be holding module_mutex. */
+/* Resolve a symbol for this module. I.e. if we find one, record usage. */
static const struct kernel_symbol *resolve_symbol(Elf_Shdr *sechdrs,
unsigned int versindex,
const char *name,
const struct kernel_symbol *sym;
const unsigned long *crc;
+ mutex_lock(&module_mutex);
sym = find_symbol(name, &owner, &crc,
!(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
/* use_module can fail due to OOM,
|| !use_module(mod, owner))
sym = NULL;
}
+ mutex_unlock(&module_mutex);
return sym;
}
#endif
#ifdef CONFIG_SYSFS
-int module_add_modinfo_attrs(struct module *mod)
+static void add_usage_links(struct module *mod)
+{
+#ifdef CONFIG_MODULE_UNLOAD
+ struct module_use *use;
+ int nowarn;
+
+ mutex_lock(&module_mutex);
+ list_for_each_entry(use, &mod->target_list, target_list) {
+ nowarn = sysfs_create_link(use->target->holders_dir,
+ &mod->mkobj.kobj, mod->name);
+ }
+ mutex_unlock(&module_mutex);
+#endif
+}
+
+static void del_usage_links(struct module *mod)
+{
+#ifdef CONFIG_MODULE_UNLOAD
+ struct module_use *use;
+
+ mutex_lock(&module_mutex);
+ list_for_each_entry(use, &mod->target_list, target_list)
+ sysfs_remove_link(use->target->holders_dir, mod->name);
+ mutex_unlock(&module_mutex);
+#endif
+}
+
+static int module_add_modinfo_attrs(struct module *mod)
{
struct module_attribute *attr;
struct module_attribute *temp_attr;
return error;
}
-void module_remove_modinfo_attrs(struct module *mod)
+static void module_remove_modinfo_attrs(struct module *mod)
{
struct module_attribute *attr;
int i;
kfree(mod->modinfo_attrs);
}
-int mod_sysfs_init(struct module *mod)
+static int mod_sysfs_init(struct module *mod)
{
int err;
struct kobject *kobj;
return err;
}
-int mod_sysfs_setup(struct module *mod,
+static int mod_sysfs_setup(struct module *mod,
struct kernel_param *kparam,
unsigned int num_params)
{
int err;
+ err = mod_sysfs_init(mod);
+ if (err)
+ goto out;
+
mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
if (!mod->holders_dir) {
err = -ENOMEM;
if (err)
goto out_unreg_param;
+ add_usage_links(mod);
+
kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
return 0;
kobject_put(mod->holders_dir);
out_unreg:
kobject_put(&mod->mkobj.kobj);
+out:
return err;
}
#else /* CONFIG_SYSFS */
+static inline int mod_sysfs_init(struct module *mod)
+{
+ return 0;
+}
+
+static inline int mod_sysfs_setup(struct module *mod,
+ struct kernel_param *kparam,
+ unsigned int num_params)
+{
+ return 0;
+}
+
+static inline int module_add_modinfo_attrs(struct module *mod)
+{
+ return 0;
+}
+
+static inline void module_remove_modinfo_attrs(struct module *mod)
+{
+}
+
static void mod_sysfs_fini(struct module *mod)
{
}
+static void del_usage_links(struct module *mod)
+{
+}
+
#endif /* CONFIG_SYSFS */
static void mod_kobject_remove(struct module *mod)
{
+ del_usage_links(mod);
module_remove_modinfo_attrs(mod);
module_param_sysfs_remove(mod);
kobject_put(mod->mkobj.drivers_dir);
return 0;
}
-/* Free a module, remove from lists, etc (must hold module_mutex). */
+/* Free a module, remove from lists, etc. */
static void free_module(struct module *mod)
{
trace_module_free(mod);
/* Delete from various lists */
+ mutex_lock(&module_mutex);
stop_machine(__unlink_module, mod, NULL);
+ mutex_unlock(&module_mutex);
remove_notes_attrs(mod);
remove_sect_attrs(mod);
mod_kobject_remove(mod);
/*
* Ensure that an exported symbol [global namespace] does not already exist
* in the kernel or in some other module's exported symbol table.
+ *
+ * You must hold the module_mutex.
*/
static int verify_export_symbols(struct module *mod)
{
void *ret = module_alloc(size);
if (ret) {
+ mutex_lock(&module_mutex);
/* Update module bounds. */
if ((unsigned long)ret < module_addr_min)
module_addr_min = (unsigned long)ret;
if ((unsigned long)ret + size > module_addr_max)
module_addr_max = (unsigned long)ret + size;
+ mutex_unlock(&module_mutex);
}
return ret;
}
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. */
/* Now we've moved module, initialize linked lists, etc. */
module_unload_init(mod);
- /* add kobject, so we can reference it. */
- err = mod_sysfs_init(mod);
- if (err)
- goto free_unload;
-
/* Set up license info based on the info section */
set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
goto cleanup;
}
- /* Find duplicate symbols */
- err = verify_export_symbols(mod);
- if (err < 0)
- goto cleanup;
-
/* Set up and sort exception table */
mod->extable = section_objs(hdr, sechdrs, secstrings, "__ex_table",
sizeof(*mod->extable), &mod->num_exentries);
* function to insert in a way safe to concurrent readers.
* The mutex protects against concurrent writers.
*/
+ mutex_lock(&module_mutex);
+ if (find_module(mod->name)) {
+ err = -EEXIST;
+ goto unlock;
+ }
+
+ /* Find duplicate symbols */
+ err = verify_export_symbols(mod);
+ if (err < 0)
+ goto unlock;
+
list_add_rcu(&mod->list, &modules);
+ mutex_unlock(&module_mutex);
err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, NULL);
if (err < 0)
err = mod_sysfs_setup(mod, mod->kp, mod->num_kp);
if (err < 0)
goto unlink;
+
add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
return mod;
unlink:
+ mutex_lock(&module_mutex);
/* Unlink carefully: kallsyms could be walking list. */
list_del_rcu(&mod->list);
+ unlock:
+ mutex_unlock(&module_mutex);
synchronize_sched();
module_arch_cleanup(mod);
cleanup:
free_modinfo(mod);
- kobject_del(&mod->mkobj.kobj);
- kobject_put(&mod->mkobj.kobj);
- free_unload:
module_unload_free(mod);
#if defined(CONFIG_MODULE_UNLOAD)
free_percpu(mod->refptr);
if (!capable(CAP_SYS_MODULE) || modules_disabled)
return -EPERM;
- /* Only one module load at a time, please */
- if (mutex_lock_interruptible(&module_mutex) != 0)
- return -EINTR;
-
/* Do all the hard work */
mod = load_module(umod, len, uargs);
- if (IS_ERR(mod)) {
- mutex_unlock(&module_mutex);
+ if (IS_ERR(mod))
return PTR_ERR(mod);
- }
-
- /* Drop lock so they can recurse */
- mutex_unlock(&module_mutex);
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_COMING, mod);
module_put(mod);
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_GOING, mod);
- mutex_lock(&module_mutex);
free_module(mod);
- mutex_unlock(&module_mutex);
wake_up(&module_wq);
return ret;
}
git://bbs.cooldavid.org / net-next-2.6.git / blobdiff