|  | // SPDX-License-Identifier: GPL-2.0-or-later | 
|  | /* | 
|  | * Module sysfs support | 
|  | * | 
|  | * Copyright (C) 2008 Rusty Russell | 
|  | */ | 
|  |  | 
|  | #include <linux/module.h> | 
|  | #include <linux/kernel.h> | 
|  | #include <linux/fs.h> | 
|  | #include <linux/sysfs.h> | 
|  | #include <linux/slab.h> | 
|  | #include <linux/kallsyms.h> | 
|  | #include <linux/mutex.h> | 
|  | #include "internal.h" | 
|  |  | 
|  | /* | 
|  | * /sys/module/foo/sections stuff | 
|  | * J. Corbet <corbet@lwn.net> | 
|  | */ | 
|  | #ifdef CONFIG_KALLSYMS | 
|  | struct module_sect_attr { | 
|  | struct bin_attribute battr; | 
|  | unsigned long address; | 
|  | }; | 
|  |  | 
|  | struct module_sect_attrs { | 
|  | struct attribute_group grp; | 
|  | unsigned int nsections; | 
|  | struct module_sect_attr attrs[]; | 
|  | }; | 
|  |  | 
|  | #define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4)) | 
|  | static ssize_t module_sect_read(struct file *file, struct kobject *kobj, | 
|  | struct bin_attribute *battr, | 
|  | char *buf, loff_t pos, size_t count) | 
|  | { | 
|  | struct module_sect_attr *sattr = | 
|  | container_of(battr, struct module_sect_attr, battr); | 
|  | char bounce[MODULE_SECT_READ_SIZE + 1]; | 
|  | size_t wrote; | 
|  |  | 
|  | if (pos != 0) | 
|  | return -EINVAL; | 
|  |  | 
|  | /* | 
|  | * Since we're a binary read handler, we must account for the | 
|  | * trailing NUL byte that sprintf will write: if "buf" is | 
|  | * too small to hold the NUL, or the NUL is exactly the last | 
|  | * byte, the read will look like it got truncated by one byte. | 
|  | * Since there is no way to ask sprintf nicely to not write | 
|  | * the NUL, we have to use a bounce buffer. | 
|  | */ | 
|  | wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n", | 
|  | kallsyms_show_value(file->f_cred) | 
|  | ? (void *)sattr->address : NULL); | 
|  | count = min(count, wrote); | 
|  | memcpy(buf, bounce, count); | 
|  |  | 
|  | return count; | 
|  | } | 
|  |  | 
|  | static void free_sect_attrs(struct module_sect_attrs *sect_attrs) | 
|  | { | 
|  | unsigned int section; | 
|  |  | 
|  | for (section = 0; section < sect_attrs->nsections; section++) | 
|  | kfree(sect_attrs->attrs[section].battr.attr.name); | 
|  | kfree(sect_attrs); | 
|  | } | 
|  |  | 
|  | static void add_sect_attrs(struct module *mod, const struct load_info *info) | 
|  | { | 
|  | unsigned int nloaded = 0, i, size[2]; | 
|  | struct module_sect_attrs *sect_attrs; | 
|  | struct module_sect_attr *sattr; | 
|  | struct bin_attribute **gattr; | 
|  |  | 
|  | /* Count loaded sections and allocate structures */ | 
|  | for (i = 0; i < info->hdr->e_shnum; i++) | 
|  | if (!sect_empty(&info->sechdrs[i])) | 
|  | nloaded++; | 
|  | size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded), | 
|  | sizeof(sect_attrs->grp.bin_attrs[0])); | 
|  | size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]); | 
|  | sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL); | 
|  | if (!sect_attrs) | 
|  | return; | 
|  |  | 
|  | /* Setup section attributes. */ | 
|  | sect_attrs->grp.name = "sections"; | 
|  | sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0]; | 
|  |  | 
|  | sect_attrs->nsections = 0; | 
|  | sattr = §_attrs->attrs[0]; | 
|  | gattr = §_attrs->grp.bin_attrs[0]; | 
|  | for (i = 0; i < info->hdr->e_shnum; i++) { | 
|  | Elf_Shdr *sec = &info->sechdrs[i]; | 
|  |  | 
|  | if (sect_empty(sec)) | 
|  | continue; | 
|  | sysfs_bin_attr_init(&sattr->battr); | 
|  | sattr->address = sec->sh_addr; | 
|  | sattr->battr.attr.name = | 
|  | kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL); | 
|  | if (!sattr->battr.attr.name) | 
|  | goto out; | 
|  | sect_attrs->nsections++; | 
|  | sattr->battr.read = module_sect_read; | 
|  | sattr->battr.size = MODULE_SECT_READ_SIZE; | 
|  | sattr->battr.attr.mode = 0400; | 
|  | *(gattr++) = &(sattr++)->battr; | 
|  | } | 
|  | *gattr = NULL; | 
|  |  | 
|  | if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp)) | 
|  | goto out; | 
|  |  | 
|  | mod->sect_attrs = sect_attrs; | 
|  | return; | 
|  | out: | 
|  | free_sect_attrs(sect_attrs); | 
|  | } | 
|  |  | 
|  | static void remove_sect_attrs(struct module *mod) | 
|  | { | 
|  | if (mod->sect_attrs) { | 
|  | sysfs_remove_group(&mod->mkobj.kobj, | 
|  | &mod->sect_attrs->grp); | 
|  | /* | 
|  | * We are positive that no one is using any sect attrs | 
|  | * at this point.  Deallocate immediately. | 
|  | */ | 
|  | free_sect_attrs(mod->sect_attrs); | 
|  | mod->sect_attrs = NULL; | 
|  | } | 
|  | } | 
|  |  | 
|  | /* | 
|  | * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections. | 
|  | */ | 
|  |  | 
|  | struct module_notes_attrs { | 
|  | struct kobject *dir; | 
|  | unsigned int notes; | 
|  | struct bin_attribute attrs[]; | 
|  | }; | 
|  |  | 
|  | static ssize_t module_notes_read(struct file *filp, struct kobject *kobj, | 
|  | struct bin_attribute *bin_attr, | 
|  | char *buf, loff_t pos, size_t count) | 
|  | { | 
|  | /* | 
|  | * The caller checked the pos and count against our size. | 
|  | */ | 
|  | memcpy(buf, bin_attr->private + pos, count); | 
|  | return count; | 
|  | } | 
|  |  | 
|  | static void free_notes_attrs(struct module_notes_attrs *notes_attrs, | 
|  | unsigned int i) | 
|  | { | 
|  | if (notes_attrs->dir) { | 
|  | while (i-- > 0) | 
|  | sysfs_remove_bin_file(notes_attrs->dir, | 
|  | ¬es_attrs->attrs[i]); | 
|  | kobject_put(notes_attrs->dir); | 
|  | } | 
|  | kfree(notes_attrs); | 
|  | } | 
|  |  | 
|  | static void add_notes_attrs(struct module *mod, const struct load_info *info) | 
|  | { | 
|  | unsigned int notes, loaded, i; | 
|  | struct module_notes_attrs *notes_attrs; | 
|  | struct bin_attribute *nattr; | 
|  |  | 
|  | /* failed to create section attributes, so can't create notes */ | 
|  | if (!mod->sect_attrs) | 
|  | return; | 
|  |  | 
|  | /* Count notes sections and allocate structures.  */ | 
|  | notes = 0; | 
|  | for (i = 0; i < info->hdr->e_shnum; i++) | 
|  | if (!sect_empty(&info->sechdrs[i]) && | 
|  | info->sechdrs[i].sh_type == SHT_NOTE) | 
|  | ++notes; | 
|  |  | 
|  | if (notes == 0) | 
|  | return; | 
|  |  | 
|  | notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes), | 
|  | GFP_KERNEL); | 
|  | if (!notes_attrs) | 
|  | return; | 
|  |  | 
|  | notes_attrs->notes = notes; | 
|  | nattr = ¬es_attrs->attrs[0]; | 
|  | for (loaded = i = 0; i < info->hdr->e_shnum; ++i) { | 
|  | if (sect_empty(&info->sechdrs[i])) | 
|  | continue; | 
|  | if (info->sechdrs[i].sh_type == SHT_NOTE) { | 
|  | sysfs_bin_attr_init(nattr); | 
|  | nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name; | 
|  | nattr->attr.mode = 0444; | 
|  | nattr->size = info->sechdrs[i].sh_size; | 
|  | nattr->private = (void *)info->sechdrs[i].sh_addr; | 
|  | nattr->read = module_notes_read; | 
|  | ++nattr; | 
|  | } | 
|  | ++loaded; | 
|  | } | 
|  |  | 
|  | notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj); | 
|  | if (!notes_attrs->dir) | 
|  | goto out; | 
|  |  | 
|  | for (i = 0; i < notes; ++i) | 
|  | if (sysfs_create_bin_file(notes_attrs->dir, | 
|  | ¬es_attrs->attrs[i])) | 
|  | goto out; | 
|  |  | 
|  | mod->notes_attrs = notes_attrs; | 
|  | return; | 
|  |  | 
|  | out: | 
|  | free_notes_attrs(notes_attrs, i); | 
|  | } | 
|  |  | 
|  | static void remove_notes_attrs(struct module *mod) | 
|  | { | 
|  | if (mod->notes_attrs) | 
|  | free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes); | 
|  | } | 
|  |  | 
|  | #else /* !CONFIG_KALLSYMS */ | 
|  | static inline void add_sect_attrs(struct module *mod, const struct load_info *info) { } | 
|  | static inline void remove_sect_attrs(struct module *mod) { } | 
|  | static inline void add_notes_attrs(struct module *mod, const struct load_info *info) { } | 
|  | static inline void remove_notes_attrs(struct module *mod) { } | 
|  | #endif /* CONFIG_KALLSYMS */ | 
|  |  | 
|  | 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 add_usage_links(struct module *mod) | 
|  | { | 
|  | int ret = 0; | 
|  | #ifdef CONFIG_MODULE_UNLOAD | 
|  | struct module_use *use; | 
|  |  | 
|  | mutex_lock(&module_mutex); | 
|  | list_for_each_entry(use, &mod->target_list, target_list) { | 
|  | ret = sysfs_create_link(use->target->holders_dir, | 
|  | &mod->mkobj.kobj, mod->name); | 
|  | if (ret) | 
|  | break; | 
|  | } | 
|  | mutex_unlock(&module_mutex); | 
|  | if (ret) | 
|  | del_usage_links(mod); | 
|  | #endif | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | static void module_remove_modinfo_attrs(struct module *mod, int end) | 
|  | { | 
|  | struct module_attribute *attr; | 
|  | int i; | 
|  |  | 
|  | for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) { | 
|  | if (end >= 0 && i > end) | 
|  | break; | 
|  | /* 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 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) * | 
|  | (modinfo_attrs_count + 1)), | 
|  | GFP_KERNEL); | 
|  | if (!mod->modinfo_attrs) | 
|  | return -ENOMEM; | 
|  |  | 
|  | temp_attr = mod->modinfo_attrs; | 
|  | for (i = 0; (attr = modinfo_attrs[i]); i++) { | 
|  | if (!attr->test || attr->test(mod)) { | 
|  | memcpy(temp_attr, attr, sizeof(*temp_attr)); | 
|  | sysfs_attr_init(&temp_attr->attr); | 
|  | error = sysfs_create_file(&mod->mkobj.kobj, | 
|  | &temp_attr->attr); | 
|  | if (error) | 
|  | goto error_out; | 
|  | ++temp_attr; | 
|  | } | 
|  | } | 
|  |  | 
|  | return 0; | 
|  |  | 
|  | error_out: | 
|  | if (i > 0) | 
|  | module_remove_modinfo_attrs(mod, --i); | 
|  | else | 
|  | kfree(mod->modinfo_attrs); | 
|  | return error; | 
|  | } | 
|  |  | 
|  | static void mod_kobject_put(struct module *mod) | 
|  | { | 
|  | DECLARE_COMPLETION_ONSTACK(c); | 
|  |  | 
|  | mod->mkobj.kobj_completion = &c; | 
|  | kobject_put(&mod->mkobj.kobj); | 
|  | wait_for_completion(&c); | 
|  | } | 
|  |  | 
|  | static int mod_sysfs_init(struct module *mod) | 
|  | { | 
|  | int err; | 
|  | struct kobject *kobj; | 
|  |  | 
|  | if (!module_sysfs_initialized) { | 
|  | pr_err("%s: module sysfs not initialized\n", mod->name); | 
|  | err = -EINVAL; | 
|  | goto out; | 
|  | } | 
|  |  | 
|  | kobj = kset_find_obj(module_kset, mod->name); | 
|  | if (kobj) { | 
|  | pr_err("%s: module is already loaded\n", mod->name); | 
|  | kobject_put(kobj); | 
|  | err = -EINVAL; | 
|  | goto out; | 
|  | } | 
|  |  | 
|  | mod->mkobj.mod = mod; | 
|  |  | 
|  | memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); | 
|  | mod->mkobj.kobj.kset = module_kset; | 
|  | err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL, | 
|  | "%s", mod->name); | 
|  | if (err) | 
|  | mod_kobject_put(mod); | 
|  |  | 
|  | out: | 
|  | return err; | 
|  | } | 
|  |  | 
|  | int mod_sysfs_setup(struct module *mod, | 
|  | const struct load_info *info, | 
|  | 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; | 
|  | goto out_unreg; | 
|  | } | 
|  |  | 
|  | err = module_param_sysfs_setup(mod, kparam, num_params); | 
|  | if (err) | 
|  | goto out_unreg_holders; | 
|  |  | 
|  | err = module_add_modinfo_attrs(mod); | 
|  | if (err) | 
|  | goto out_unreg_param; | 
|  |  | 
|  | err = add_usage_links(mod); | 
|  | if (err) | 
|  | goto out_unreg_modinfo_attrs; | 
|  |  | 
|  | add_sect_attrs(mod, info); | 
|  | add_notes_attrs(mod, info); | 
|  |  | 
|  | return 0; | 
|  |  | 
|  | out_unreg_modinfo_attrs: | 
|  | module_remove_modinfo_attrs(mod, -1); | 
|  | out_unreg_param: | 
|  | module_param_sysfs_remove(mod); | 
|  | out_unreg_holders: | 
|  | kobject_put(mod->holders_dir); | 
|  | out_unreg: | 
|  | mod_kobject_put(mod); | 
|  | out: | 
|  | return err; | 
|  | } | 
|  |  | 
|  | static void mod_sysfs_fini(struct module *mod) | 
|  | { | 
|  | remove_notes_attrs(mod); | 
|  | remove_sect_attrs(mod); | 
|  | mod_kobject_put(mod); | 
|  | } | 
|  |  | 
|  | void mod_sysfs_teardown(struct module *mod) | 
|  | { | 
|  | del_usage_links(mod); | 
|  | module_remove_modinfo_attrs(mod, -1); | 
|  | module_param_sysfs_remove(mod); | 
|  | kobject_put(mod->mkobj.drivers_dir); | 
|  | kobject_put(mod->holders_dir); | 
|  | mod_sysfs_fini(mod); | 
|  | } | 
|  |  | 
|  | void init_param_lock(struct module *mod) | 
|  | { | 
|  | mutex_init(&mod->param_lock); | 
|  | } |