/* * Originally from efivars.c, * * Copyright (C) 2001,2003,2004 Dell * Copyright (C) 2004 Intel Corporation * * This code takes all variables accessible from EFI runtime and * exports them via sysfs * * 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 * * Changelog: * * 17 May 2004 - Matt Domsch * remove check for efi_enabled in exit * add MODULE_VERSION * * 26 Apr 2004 - Matt Domsch * minor bug fixes * * 21 Apr 2004 - Matt Tolentino * fix locking per Peter Chubb's findings * * 25 Mar 2002 - Matt Domsch * move uuid_unparse() to include/asm-ia64/efi.h:efi_guid_to_str() * * 12 Feb 2002 - Matt Domsch * use list_for_each_safe when deleting vars. * remove ifdef CONFIG_SMP around include * v0.04 release to linux-ia64@linuxia64.org * * 20 April 2001 - Matt Domsch * Moved vars from /proc/efi to /proc/efi/vars, and made * efi.c own the /proc/efi directory. * v0.03 release to linux-ia64@linuxia64.org * * 26 March 2001 - Matt Domsch * At the request of Stephane, moved ownership of /proc/efi * to efi.c, and now efivars lives under /proc/efi/vars. * * 12 March 2001 - Matt Domsch * Feedback received from Stephane Eranian incorporated. * efivar_write() checks copy_from_user() return value. * efivar_read/write() returns proper errno. * v0.02 release to linux-ia64@linuxia64.org * * 26 February 2001 - Matt Domsch * v0.01 release to linux-ia64@linuxia64.org */ #include #include #include #include #include #define EFIVARS_VERSION "0.08" #define EFIVARS_DATE "2004-May-17" MODULE_AUTHOR("Matt Domsch "); MODULE_DESCRIPTION("sysfs interface to EFI Variables"); MODULE_LICENSE("GPL"); MODULE_VERSION(EFIVARS_VERSION); MODULE_ALIAS("platform:efivars"); LIST_HEAD(efivar_sysfs_list); EXPORT_SYMBOL_GPL(efivar_sysfs_list); static struct kset *efivars_kset; static struct bin_attribute *efivars_new_var; static struct bin_attribute *efivars_del_var; struct compat_efi_variable { efi_char16_t VariableName[EFI_VAR_NAME_LEN/sizeof(efi_char16_t)]; efi_guid_t VendorGuid; __u32 DataSize; __u8 Data[1024]; __u32 Status; __u32 Attributes; } __packed; struct efivar_attribute { struct attribute attr; ssize_t (*show) (struct efivar_entry *entry, char *buf); ssize_t (*store)(struct efivar_entry *entry, const char *buf, size_t count); }; #define EFIVAR_ATTR(_name, _mode, _show, _store) \ struct efivar_attribute efivar_attr_##_name = { \ .attr = {.name = __stringify(_name), .mode = _mode}, \ .show = _show, \ .store = _store, \ }; #define to_efivar_attr(_attr) container_of(_attr, struct efivar_attribute, attr) #define to_efivar_entry(obj) container_of(obj, struct efivar_entry, kobj) /* * Prototype for sysfs creation function */ static int efivar_create_sysfs_entry(struct efivar_entry *new_var); static ssize_t efivar_guid_read(struct efivar_entry *entry, char *buf) { struct efi_variable *var = &entry->var; char *str = buf; if (!entry || !buf) return 0; efi_guid_to_str(&var->VendorGuid, str); str += strlen(str); str += sprintf(str, "\n"); return str - buf; } static ssize_t efivar_attr_read(struct efivar_entry *entry, char *buf) { struct efi_variable *var = &entry->var; unsigned long size = sizeof(var->Data); char *str = buf; int ret; if (!entry || !buf) return -EINVAL; ret = efivar_entry_get(entry, &var->Attributes, &size, var->Data); var->DataSize = size; if (ret) return -EIO; if (var->Attributes & EFI_VARIABLE_NON_VOLATILE) str += sprintf(str, "EFI_VARIABLE_NON_VOLATILE\n"); if (var->Attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS) str += sprintf(str, "EFI_VARIABLE_BOOTSERVICE_ACCESS\n"); if (var->Attributes & EFI_VARIABLE_RUNTIME_ACCESS) str += sprintf(str, "EFI_VARIABLE_RUNTIME_ACCESS\n"); if (var->Attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD) str += sprintf(str, "EFI_VARIABLE_HARDWARE_ERROR_RECORD\n"); if (var->Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) str += sprintf(str, "EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS\n"); if (var->Attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) str += sprintf(str, "EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS\n"); if (var->Attributes & EFI_VARIABLE_APPEND_WRITE) str += sprintf(str, "EFI_VARIABLE_APPEND_WRITE\n"); return str - buf; } static ssize_t efivar_size_read(struct efivar_entry *entry, char *buf) { struct efi_variable *var = &entry->var; unsigned long size = sizeof(var->Data); char *str = buf; int ret; if (!entry || !buf) return -EINVAL; ret = efivar_entry_get(entry, &var->Attributes, &size, var->Data); var->DataSize = size; if (ret) return -EIO; str += sprintf(str, "0x%lx\n", var->DataSize); return str - buf; } static ssize_t efivar_data_read(struct efivar_entry *entry, char *buf) { struct efi_variable *var = &entry->var; unsigned long size = sizeof(var->Data); int ret; if (!entry || !buf) return -EINVAL; ret = efivar_entry_get(entry, &var->Attributes, &size, var->Data); var->DataSize = size; if (ret) return -EIO; memcpy(buf, var->Data, var->DataSize); return var->DataSize; } static inline int sanity_check(struct efi_variable *var, efi_char16_t *name, efi_guid_t vendor, unsigned long size, u32 attributes, u8 *data) { /* * If only updating the variable data, then the name * and guid should remain the same */ if (memcmp(name, var->VariableName, sizeof(var->VariableName)) || efi_guidcmp(vendor, var->VendorGuid)) { printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n"); return -EINVAL; } if ((size <= 0) || (attributes == 0)){ printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n"); return -EINVAL; } if ((attributes & ~EFI_VARIABLE_MASK) != 0 || efivar_validate(vendor, name, data, size) == false) { printk(KERN_ERR "efivars: Malformed variable content\n"); return -EINVAL; } return 0; } static inline bool is_compat(void) { if (IS_ENABLED(CONFIG_COMPAT) && is_compat_task()) return true; return false; } static void copy_out_compat(struct efi_variable *dst, struct compat_efi_variable *src) { memcpy(dst->VariableName, src->VariableName, EFI_VAR_NAME_LEN); memcpy(dst->Data, src->Data, sizeof(src->Data)); dst->VendorGuid = src->VendorGuid; dst->DataSize = src->DataSize; dst->Attributes = src->Attributes; } /* * We allow each variable to be edited via rewriting the * entire efi variable structure. */ static ssize_t efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count) { struct efi_variable *new_var, *var = &entry->var; efi_char16_t *name; unsigned long size; efi_guid_t vendor; u32 attributes; u8 *data; int err; if (!entry || !buf) return -EINVAL; if (is_compat()) { struct compat_efi_variable *compat; if (count != sizeof(*compat)) return -EINVAL; compat = (struct compat_efi_variable *)buf; attributes = compat->Attributes; vendor = compat->VendorGuid; name = compat->VariableName; size = compat->DataSize; data = compat->Data; err = sanity_check(var, name, vendor, size, attributes, data); if (err) return err; copy_out_compat(&entry->var, compat); } else { if (count != sizeof(struct efi_variable)) return -EINVAL; new_var = (struct efi_variable *)buf; attributes = new_var->Attributes; vendor = new_var->VendorGuid; name = new_var->VariableName; size = new_var->DataSize; data = new_var->Data; err = sanity_check(var, name, vendor, size, attributes, data); if (err) return err; memcpy(&entry->var, new_var, count); } err = efivar_entry_set(entry, attributes, size, data, NULL); if (err) { printk(KERN_WARNING "efivars: set_variable() failed: status=%d\n", err); return -EIO; } return count; } static ssize_t efivar_show_raw(struct efivar_entry *entry, char *buf) { struct efi_variable *var = &entry->var; struct compat_efi_variable *compat; unsigned long datasize = sizeof(var->Data); size_t size; int ret; if (!entry || !buf) return 0; ret = efivar_entry_get(entry, &var->Attributes, &datasize, var->Data); var->DataSize = datasize; if (ret) return -EIO; if (is_compat()) { compat = (struct compat_efi_variable *)buf; size = sizeof(*compat); memcpy(compat->VariableName, var->VariableName, EFI_VAR_NAME_LEN); memcpy(compat->Data, var->Data, sizeof(compat->Data)); compat->VendorGuid = var->VendorGuid; compat->DataSize = var->DataSize; compat->Attributes = var->Attributes; } else { size = sizeof(*var); memcpy(buf, var, size); } return size; } /* * Generic read/write functions that call the specific functions of * the attributes... */ static ssize_t efivar_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) { struct efivar_entry *var = to_efivar_entry(kobj); struct efivar_attribute *efivar_attr = to_efivar_attr(attr); ssize_t ret = -EIO; if (!capable(CAP_SYS_ADMIN)) return -EACCES; if (efivar_attr->show) { ret = efivar_attr->show(var, buf); } return ret; } static ssize_t efivar_attr_store(struct kobject *kobj, struct attribute *attr, const char *buf, size_t count) { struct efivar_entry *var = to_efivar_entry(kobj); struct efivar_attribute *efivar_attr = to_efivar_attr(attr); ssize_t ret = -EIO; if (!capable(CAP_SYS_ADMIN)) return -EACCES; if (efivar_attr->store) ret = efivar_attr->store(var, buf, count); return ret; } static const struct sysfs_ops efivar_attr_ops = { .show = efivar_attr_show, .store = efivar_attr_store, }; static void efivar_release(struct kobject *kobj) { struct efivar_entry *var = container_of(kobj, struct efivar_entry, kobj); kfree(var); } static EFIVAR_ATTR(guid, 0400, efivar_guid_read, NULL); static EFIVAR_ATTR(attributes, 0400, efivar_attr_read, NULL); static EFIVAR_ATTR(size, 0400, efivar_size_read, NULL); static EFIVAR_ATTR(data, 0400, efivar_data_read, NULL); static EFIVAR_ATTR(raw_var, 0600, efivar_show_raw, efivar_store_raw); static struct attribute *def_attrs[] = { &efivar_attr_guid.attr, &efivar_attr_size.attr, &efivar_attr_attributes.attr, &efivar_attr_data.attr, &efivar_attr_raw_var.attr, NULL, }; static struct kobj_type efivar_ktype = { .release = efivar_release, .sysfs_ops = &efivar_attr_ops, .default_attrs = def_attrs, }; static ssize_t efivar_create(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t pos, size_t count) { struct compat_efi_variable *compat = (struct compat_efi_variable *)buf; struct efi_variable *new_var = (struct efi_variable *)buf; struct efivar_entry *new_entry; bool need_compat = is_compat(); efi_char16_t *name; unsigned long size; u32 attributes; u8 *data; int err; if (!capable(CAP_SYS_ADMIN)) return -EACCES; if (need_compat) { if (count != sizeof(*compat)) return -EINVAL; attributes = compat->Attributes; name = compat->VariableName; size = compat->DataSize; data = compat->Data; } else { if (count != sizeof(*new_var)) return -EINVAL; attributes = new_var->Attributes; name = new_var->VariableName; size = new_var->DataSize; data = new_var->Data; } if ((attributes & ~EFI_VARIABLE_MASK) != 0 || efivar_validate(new_var->VendorGuid, name, data, size) == false) { printk(KERN_ERR "efivars: Malformed variable content\n"); return -EINVAL; } new_entry = kzalloc(sizeof(*new_entry), GFP_KERNEL); if (!new_entry) return -ENOMEM; if (need_compat) copy_out_compat(&new_entry->var, compat); else memcpy(&new_entry->var, new_var, sizeof(*new_var)); err = efivar_entry_set(new_entry, attributes, size, data, &efivar_sysfs_list); if (err) { if (err == -EEXIST) err = -EINVAL; goto out; } if (efivar_create_sysfs_entry(new_entry)) { printk(KERN_WARNING "efivars: failed to create sysfs entry.\n"); kfree(new_entry); } return count; out: kfree(new_entry); return err; } static ssize_t efivar_delete(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t pos, size_t count) { struct efi_variable *del_var = (struct efi_variable *)buf; struct compat_efi_variable *compat; struct efivar_entry *entry; efi_char16_t *name; efi_guid_t vendor; int err = 0; if (!capable(CAP_SYS_ADMIN)) return -EACCES; if (is_compat()) { if (count != sizeof(*compat)) return -EINVAL; compat = (struct compat_efi_variable *)buf; name = compat->VariableName; vendor = compat->VendorGuid; } else { if (count != sizeof(*del_var)) return -EINVAL; name = del_var->VariableName; vendor = del_var->VendorGuid; } efivar_entry_iter_begin(); entry = efivar_entry_find(name, vendor, &efivar_sysfs_list, true); if (!entry) err = -EINVAL; else if (__efivar_entry_delete(entry)) err = -EIO; if (err) { efivar_entry_iter_end(); return err; } if (!entry->scanning) { efivar_entry_iter_end(); efivar_unregister(entry); } else efivar_entry_iter_end(); /* It's dead Jim.... */ return count; } /** * efivar_create_sysfs_entry - create a new entry in sysfs * @new_var: efivar entry to create * * Returns 0 on success, negative error code on failure */ static int efivar_create_sysfs_entry(struct efivar_entry *new_var) { int short_name_size; char *short_name; unsigned long utf8_name_size; efi_char16_t *variable_name = new_var->var.VariableName; int ret; /* * Length of the variable bytes in UTF8, plus the '-' separator, * plus the GUID, plus trailing NUL */ utf8_name_size = ucs2_utf8size(variable_name); short_name_size = utf8_name_size + 1 + EFI_VARIABLE_GUID_LEN + 1; short_name = kmalloc(short_name_size, GFP_KERNEL); if (!short_name) return -ENOMEM; ucs2_as_utf8(short_name, variable_name, short_name_size); /* This is ugly, but necessary to separate one vendor's private variables from another's. */ short_name[utf8_name_size] = '-'; efi_guid_to_str(&new_var->var.VendorGuid, short_name + utf8_name_size + 1); new_var->kobj.kset = efivars_kset; ret = kobject_init_and_add(&new_var->kobj, &efivar_ktype, NULL, "%s", short_name); kfree(short_name); if (ret) { kobject_put(&new_var->kobj); return ret; } kobject_uevent(&new_var->kobj, KOBJ_ADD); efivar_entry_add(new_var, &efivar_sysfs_list); return 0; } static int create_efivars_bin_attributes(void) { struct bin_attribute *attr; int error; /* new_var */ attr = kzalloc(sizeof(*attr), GFP_KERNEL); if (!attr) return -ENOMEM; attr->attr.name = "new_var"; attr->attr.mode = 0200; attr->write = efivar_create; efivars_new_var = attr; /* del_var */ attr = kzalloc(sizeof(*attr), GFP_KERNEL); if (!attr) { error = -ENOMEM; goto out_free; } attr->attr.name = "del_var"; attr->attr.mode = 0200; attr->write = efivar_delete; efivars_del_var = attr; sysfs_bin_attr_init(efivars_new_var); sysfs_bin_attr_init(efivars_del_var); /* Register */ error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_new_var); if (error) { printk(KERN_ERR "efivars: unable to create new_var sysfs file" " due to error %d\n", error); goto out_free; } error = sysfs_create_bin_file(&efivars_kset->kobj, efivars_del_var); if (error) { printk(KERN_ERR "efivars: unable to create del_var sysfs file" " due to error %d\n", error); sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var); goto out_free; } return 0; out_free: kfree(efivars_del_var); efivars_del_var = NULL; kfree(efivars_new_var); efivars_new_var = NULL; return error; } static int efivar_update_sysfs_entry(efi_char16_t *name, efi_guid_t vendor, unsigned long name_size, void *data) { struct efivar_entry *entry = data; if (efivar_entry_find(name, vendor, &efivar_sysfs_list, false)) return 0; memcpy(entry->var.VariableName, name, name_size); memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t)); return 1; } static void efivar_update_sysfs_entries(struct work_struct *work) { struct efivar_entry *entry; int err; /* Add new sysfs entries */ while (1) { entry = kzalloc(sizeof(*entry), GFP_KERNEL); if (!entry) return; err = efivar_init(efivar_update_sysfs_entry, entry, true, false, &efivar_sysfs_list); if (!err) break; efivar_create_sysfs_entry(entry); } kfree(entry); } static int efivars_sysfs_callback(efi_char16_t *name, efi_guid_t vendor, unsigned long name_size, void *data) { struct efivar_entry *entry; entry = kzalloc(sizeof(*entry), GFP_KERNEL); if (!entry) return -ENOMEM; memcpy(entry->var.VariableName, name, name_size); memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t)); efivar_create_sysfs_entry(entry); return 0; } static int efivar_sysfs_destroy(struct efivar_entry *entry, void *data) { efivar_entry_remove(entry); efivar_unregister(entry); return 0; } static void efivars_sysfs_exit(void) { /* Remove all entries and destroy */ __efivar_entry_iter(efivar_sysfs_destroy, &efivar_sysfs_list, NULL, NULL); if (efivars_new_var) sysfs_remove_bin_file(&efivars_kset->kobj, efivars_new_var); if (efivars_del_var) sysfs_remove_bin_file(&efivars_kset->kobj, efivars_del_var); kfree(efivars_new_var); kfree(efivars_del_var); kset_unregister(efivars_kset); } int efivars_sysfs_init(void) { struct kobject *parent_kobj = efivars_kobject(); int error = 0; if (!efi_enabled(EFI_RUNTIME_SERVICES)) return -ENODEV; /* No efivars has been registered yet */ if (!parent_kobj) return 0; printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION, EFIVARS_DATE); efivars_kset = kset_create_and_add("vars", NULL, parent_kobj); if (!efivars_kset) { printk(KERN_ERR "efivars: Subsystem registration failed.\n"); return -ENOMEM; } efivar_init(efivars_sysfs_callback, NULL, false, true, &efivar_sysfs_list); error = create_efivars_bin_attributes(); if (error) { efivars_sysfs_exit(); return error; } INIT_WORK(&efivar_work, efivar_update_sysfs_entries); return 0; } EXPORT_SYMBOL_GPL(efivars_sysfs_init); module_init(efivars_sysfs_init); module_exit(efivars_sysfs_exit);