/* * EFI Variables - 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_unparse() * * 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 #include #include #include #include #include #include #include #include #include #include #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); #define DUMP_NAME_LEN 52 /* * Length of a GUID string (strlen("aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee")) * not including trailing NUL */ #define GUID_LEN 36 static bool efivars_pstore_disable = IS_ENABLED(CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE); module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644); /* * The maximum size of VariableName + Data = 1024 * Therefore, it's reasonable to save that much * space in each part of the structure, * and we use a page for reading/writing. */ struct efi_variable { efi_char16_t VariableName[1024/sizeof(efi_char16_t)]; efi_guid_t VendorGuid; unsigned long DataSize; __u8 Data[1024]; efi_status_t Status; __u32 Attributes; } __attribute__((packed)); struct efivar_entry { struct efivars *efivars; struct efi_variable var; struct list_head list; struct kobject kobj; }; 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); }; static struct efivars __efivars; static struct efivar_operations ops; #define PSTORE_EFI_ATTRIBUTES \ (EFI_VARIABLE_NON_VOLATILE | \ EFI_VARIABLE_BOOTSERVICE_ACCESS | \ EFI_VARIABLE_RUNTIME_ACCESS) #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 efivars *efivars, unsigned long variable_name_size, efi_char16_t *variable_name, efi_guid_t *vendor_guid); /* * Prototype for workqueue functions updating sysfs entry */ static void efivar_update_sysfs_entries(struct work_struct *); static DECLARE_WORK(efivar_work, efivar_update_sysfs_entries); static bool efivar_wq_enabled = true; /* Return the number of unicode characters in data */ static unsigned long utf16_strnlen(efi_char16_t *s, size_t maxlength) { unsigned long length = 0; while (*s++ != 0 && length < maxlength) length++; return length; } static inline unsigned long utf16_strlen(efi_char16_t *s) { return utf16_strnlen(s, ~0UL); } /* * Return the number of bytes is the length of this string * Note: this is NOT the same as the number of unicode characters */ static inline unsigned long utf16_strsize(efi_char16_t *data, unsigned long maxlength) { return utf16_strnlen(data, maxlength/sizeof(efi_char16_t)) * sizeof(efi_char16_t); } static inline int utf16_strncmp(const efi_char16_t *a, const efi_char16_t *b, size_t len) { while (1) { if (len == 0) return 0; if (*a < *b) return -1; if (*a > *b) return 1; if (*a == 0) /* implies *b == 0 */ return 0; a++; b++; len--; } } static bool validate_device_path(struct efi_variable *var, int match, u8 *buffer, unsigned long len) { struct efi_generic_dev_path *node; int offset = 0; node = (struct efi_generic_dev_path *)buffer; if (len < sizeof(*node)) return false; while (offset <= len - sizeof(*node) && node->length >= sizeof(*node) && node->length <= len - offset) { offset += node->length; if ((node->type == EFI_DEV_END_PATH || node->type == EFI_DEV_END_PATH2) && node->sub_type == EFI_DEV_END_ENTIRE) return true; node = (struct efi_generic_dev_path *)(buffer + offset); } /* * If we're here then either node->length pointed past the end * of the buffer or we reached the end of the buffer without * finding a device path end node. */ return false; } static bool validate_boot_order(struct efi_variable *var, int match, u8 *buffer, unsigned long len) { /* An array of 16-bit integers */ if ((len % 2) != 0) return false; return true; } static bool validate_load_option(struct efi_variable *var, int match, u8 *buffer, unsigned long len) { u16 filepathlength; int i, desclength = 0, namelen; namelen = utf16_strnlen(var->VariableName, sizeof(var->VariableName)); /* Either "Boot" or "Driver" followed by four digits of hex */ for (i = match; i < match+4; i++) { if (var->VariableName[i] > 127 || hex_to_bin(var->VariableName[i] & 0xff) < 0) return true; } /* Reject it if there's 4 digits of hex and then further content */ if (namelen > match + 4) return false; /* A valid entry must be at least 8 bytes */ if (len < 8) return false; filepathlength = buffer[4] | buffer[5] << 8; /* * There's no stored length for the description, so it has to be * found by hand */ desclength = utf16_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2; /* Each boot entry must have a descriptor */ if (!desclength) return false; /* * If the sum of the length of the description, the claimed filepath * length and the original header are greater than the length of the * variable, it's malformed */ if ((desclength + filepathlength + 6) > len) return false; /* * And, finally, check the filepath */ return validate_device_path(var, match, buffer + desclength + 6, filepathlength); } static bool validate_uint16(struct efi_variable *var, int match, u8 *buffer, unsigned long len) { /* A single 16-bit integer */ if (len != 2) return false; return true; } static bool validate_ascii_string(struct efi_variable *var, int match, u8 *buffer, unsigned long len) { int i; for (i = 0; i < len; i++) { if (buffer[i] > 127) return false; if (buffer[i] == 0) return true; } return false; } struct variable_validate { char *name; bool (*validate)(struct efi_variable *var, int match, u8 *data, unsigned long len); }; static const struct variable_validate variable_validate[] = { { "BootNext", validate_uint16 }, { "BootOrder", validate_boot_order }, { "DriverOrder", validate_boot_order }, { "Boot*", validate_load_option }, { "Driver*", validate_load_option }, { "ConIn", validate_device_path }, { "ConInDev", validate_device_path }, { "ConOut", validate_device_path }, { "ConOutDev", validate_device_path }, { "ErrOut", validate_device_path }, { "ErrOutDev", validate_device_path }, { "Timeout", validate_uint16 }, { "Lang", validate_ascii_string }, { "PlatformLang", validate_ascii_string }, { "", NULL }, }; static bool validate_var(struct efi_variable *var, u8 *data, unsigned long len) { int i; u16 *unicode_name = var->VariableName; for (i = 0; variable_validate[i].validate != NULL; i++) { const char *name = variable_validate[i].name; int match; for (match = 0; ; match++) { char c = name[match]; u16 u = unicode_name[match]; /* All special variables are plain ascii */ if (u > 127) return true; /* Wildcard in the matching name means we've matched */ if (c == '*') return variable_validate[i].validate(var, match, data, len); /* Case sensitive match */ if (c != u) break; /* Reached the end of the string while matching */ if (!c) return variable_validate[i].validate(var, match, data, len); } } return true; } static efi_status_t get_var_data_locked(struct efivars *efivars, struct efi_variable *var) { efi_status_t status; var->DataSize = 1024; status = efivars->ops->get_variable(var->VariableName, &var->VendorGuid, &var->Attributes, &var->DataSize, var->Data); return status; } static efi_status_t get_var_data(struct efivars *efivars, struct efi_variable *var) { efi_status_t status; unsigned long flags; spin_lock_irqsave(&efivars->lock, flags); status = get_var_data_locked(efivars, var); spin_unlock_irqrestore(&efivars->lock, flags); if (status != EFI_SUCCESS) { printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n", status); } return status; } static efi_status_t check_var_size_locked(struct efivars *efivars, u32 attributes, unsigned long size) { u64 storage_size, remaining_size, max_size; efi_status_t status; const struct efivar_operations *fops = efivars->ops; if (!efivars->ops->query_variable_info) return EFI_UNSUPPORTED; status = fops->query_variable_info(attributes, &storage_size, &remaining_size, &max_size); if (status != EFI_SUCCESS) return status; if (!storage_size || size > remaining_size || size > max_size || (remaining_size - size) < (storage_size / 2)) return EFI_OUT_OF_RESOURCES; return status; } static efi_status_t check_var_size(struct efivars *efivars, u32 attributes, unsigned long size) { efi_status_t status; unsigned long flags; spin_lock_irqsave(&efivars->lock, flags); status = check_var_size_locked(efivars, attributes, size); spin_unlock_irqrestore(&efivars->lock, flags); return status; } 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_unparse(&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; char *str = buf; efi_status_t status; if (!entry || !buf) return -EINVAL; status = get_var_data(entry->efivars, var); if (status != EFI_SUCCESS) 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; char *str = buf; efi_status_t status; if (!entry || !buf) return -EINVAL; status = get_var_data(entry->efivars, var); if (status != EFI_SUCCESS) 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; efi_status_t status; if (!entry || !buf) return -EINVAL; status = get_var_data(entry->efivars, var); if (status != EFI_SUCCESS) return -EIO; memcpy(buf, var->Data, var->DataSize); return var->DataSize; } /* * 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; struct efivars *efivars = entry->efivars; efi_status_t status = EFI_NOT_FOUND; if (count != sizeof(struct efi_variable)) return -EINVAL; new_var = (struct efi_variable *)buf; /* * If only updating the variable data, then the name * and guid should remain the same */ if (memcmp(new_var->VariableName, var->VariableName, sizeof(var->VariableName)) || efi_guidcmp(new_var->VendorGuid, var->VendorGuid)) { printk(KERN_ERR "efivars: Cannot edit the wrong variable!\n"); return -EINVAL; } if ((new_var->DataSize <= 0) || (new_var->Attributes == 0)){ printk(KERN_ERR "efivars: DataSize & Attributes must be valid!\n"); return -EINVAL; } if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 || validate_var(new_var, new_var->Data, new_var->DataSize) == false) { printk(KERN_ERR "efivars: Malformed variable content\n"); return -EINVAL; } spin_lock_irq(&efivars->lock); status = check_var_size_locked(efivars, new_var->Attributes, new_var->DataSize + utf16_strsize(new_var->VariableName, 1024)); if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED) status = efivars->ops->set_variable(new_var->VariableName, &new_var->VendorGuid, new_var->Attributes, new_var->DataSize, new_var->Data); spin_unlock_irq(&efivars->lock); if (status != EFI_SUCCESS) { printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n", status); return -EIO; } memcpy(&entry->var, new_var, count); return count; } static ssize_t efivar_show_raw(struct efivar_entry *entry, char *buf) { struct efi_variable *var = &entry->var; efi_status_t status; if (!entry || !buf) return 0; status = get_var_data(entry->efivars, var); if (status != EFI_SUCCESS) return -EIO; memcpy(buf, var, sizeof(*var)); return sizeof(*var); } /* * 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 inline void efivar_unregister(struct efivar_entry *var) { kobject_put(&var->kobj); } static int efivarfs_file_open(struct inode *inode, struct file *file) { file->private_data = inode->i_private; return 0; } static int efi_status_to_err(efi_status_t status) { int err; switch (status) { case EFI_INVALID_PARAMETER: err = -EINVAL; break; case EFI_OUT_OF_RESOURCES: err = -ENOSPC; break; case EFI_DEVICE_ERROR: err = -EIO; break; case EFI_WRITE_PROTECTED: err = -EROFS; break; case EFI_SECURITY_VIOLATION: err = -EACCES; break; case EFI_NOT_FOUND: err = -EIO; break; default: err = -EINVAL; } return err; } static ssize_t efivarfs_file_write(struct file *file, const char __user *userbuf, size_t count, loff_t *ppos) { struct efivar_entry *var = file->private_data; struct efivars *efivars; efi_status_t status; void *data; u32 attributes; struct inode *inode = file->f_mapping->host; unsigned long datasize = count - sizeof(attributes); unsigned long newdatasize, varsize; ssize_t bytes = 0; if (count < sizeof(attributes)) return -EINVAL; if (copy_from_user(&attributes, userbuf, sizeof(attributes))) return -EFAULT; if (attributes & ~(EFI_VARIABLE_MASK)) return -EINVAL; efivars = var->efivars; /* * Ensure that the user can't allocate arbitrarily large * amounts of memory. Pick a default size of 64K if * QueryVariableInfo() isn't supported by the firmware. */ varsize = datasize + utf16_strsize(var->var.VariableName, 1024); status = check_var_size(efivars, attributes, varsize); if (status != EFI_SUCCESS) { if (status != EFI_UNSUPPORTED) return efi_status_to_err(status); if (datasize > 65536) return -ENOSPC; } data = kmalloc(datasize, GFP_KERNEL); if (!data) return -ENOMEM; if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) { bytes = -EFAULT; goto out; } if (validate_var(&var->var, data, datasize) == false) { bytes = -EINVAL; goto out; } /* * The lock here protects the get_variable call, the conditional * set_variable call, and removal of the variable from the efivars * list (in the case of an authenticated delete). */ spin_lock_irq(&efivars->lock); /* * Ensure that the available space hasn't shrunk below the safe level */ status = check_var_size_locked(efivars, attributes, varsize); if (status != EFI_SUCCESS && status != EFI_UNSUPPORTED) { spin_unlock_irq(&efivars->lock); kfree(data); return efi_status_to_err(status); } status = efivars->ops->set_variable(var->var.VariableName, &var->var.VendorGuid, attributes, datasize, data); if (status != EFI_SUCCESS) { spin_unlock_irq(&efivars->lock); kfree(data); return efi_status_to_err(status); } bytes = count; /* * Writing to the variable may have caused a change in size (which * could either be an append or an overwrite), or the variable to be * deleted. Perform a GetVariable() so we can tell what actually * happened. */ newdatasize = 0; status = efivars->ops->get_variable(var->var.VariableName, &var->var.VendorGuid, NULL, &newdatasize, NULL); if (status == EFI_BUFFER_TOO_SMALL) { spin_unlock_irq(&efivars->lock); mutex_lock(&inode->i_mutex); i_size_write(inode, newdatasize + sizeof(attributes)); mutex_unlock(&inode->i_mutex); } else if (status == EFI_NOT_FOUND) { list_del(&var->list); spin_unlock_irq(&efivars->lock); efivar_unregister(var); drop_nlink(inode); d_delete(file->f_dentry); dput(file->f_dentry); } else { spin_unlock_irq(&efivars->lock); pr_warn("efivarfs: inconsistent EFI variable implementation? " "status = %lx\n", status); } out: kfree(data); return bytes; } static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, size_t count, loff_t *ppos) { struct efivar_entry *var = file->private_data; struct efivars *efivars = var->efivars; efi_status_t status; unsigned long datasize = 0; u32 attributes; void *data; ssize_t size = 0; spin_lock_irq(&efivars->lock); status = efivars->ops->get_variable(var->var.VariableName, &var->var.VendorGuid, &attributes, &datasize, NULL); spin_unlock_irq(&efivars->lock); if (status != EFI_BUFFER_TOO_SMALL) return efi_status_to_err(status); data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL); if (!data) return -ENOMEM; spin_lock_irq(&efivars->lock); status = efivars->ops->get_variable(var->var.VariableName, &var->var.VendorGuid, &attributes, &datasize, (data + sizeof(attributes))); spin_unlock_irq(&efivars->lock); if (status != EFI_SUCCESS) { size = efi_status_to_err(status); goto out_free; } memcpy(data, &attributes, sizeof(attributes)); size = simple_read_from_buffer(userbuf, count, ppos, data, datasize + sizeof(attributes)); out_free: kfree(data); return size; } static void efivarfs_evict_inode(struct inode *inode) { clear_inode(inode); } static const struct super_operations efivarfs_ops = { .statfs = simple_statfs, .drop_inode = generic_delete_inode, .evict_inode = efivarfs_evict_inode, .show_options = generic_show_options, }; static struct super_block *efivarfs_sb; static const struct inode_operations efivarfs_dir_inode_operations; static const struct file_operations efivarfs_file_operations = { .open = efivarfs_file_open, .read = efivarfs_file_read, .write = efivarfs_file_write, .llseek = no_llseek, }; static struct inode *efivarfs_get_inode(struct super_block *sb, const struct inode *dir, int mode, dev_t dev) { struct inode *inode = new_inode(sb); if (inode) { inode->i_ino = get_next_ino(); inode->i_mode = mode; inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; switch (mode & S_IFMT) { case S_IFREG: inode->i_fop = &efivarfs_file_operations; break; case S_IFDIR: inode->i_op = &efivarfs_dir_inode_operations; inode->i_fop = &simple_dir_operations; inc_nlink(inode); break; } } return inode; } /* * Return true if 'str' is a valid efivarfs filename of the form, * * VariableName-12345678-1234-1234-1234-1234567891bc */ static bool efivarfs_valid_name(const char *str, int len) { static const char dashes[GUID_LEN] = { [8] = 1, [13] = 1, [18] = 1, [23] = 1 }; const char *s = str + len - GUID_LEN; int i; /* * We need a GUID, plus at least one letter for the variable name, * plus the '-' separator */ if (len < GUID_LEN + 2) return false; /* GUID must be preceded by a '-' */ if (*(s - 1) != '-') return false; /* * Validate that 's' is of the correct format, e.g. * * 12345678-1234-1234-1234-123456789abc */ for (i = 0; i < GUID_LEN; i++) { if (dashes[i]) { if (*s++ != '-') return false; } else { if (!isxdigit(*s++)) return false; } } return true; } static void efivarfs_hex_to_guid(const char *str, efi_guid_t *guid) { guid->b[0] = hex_to_bin(str[6]) << 4 | hex_to_bin(str[7]); guid->b[1] = hex_to_bin(str[4]) << 4 | hex_to_bin(str[5]); guid->b[2] = hex_to_bin(str[2]) << 4 | hex_to_bin(str[3]); guid->b[3] = hex_to_bin(str[0]) << 4 | hex_to_bin(str[1]); guid->b[4] = hex_to_bin(str[11]) << 4 | hex_to_bin(str[12]); guid->b[5] = hex_to_bin(str[9]) << 4 | hex_to_bin(str[10]); guid->b[6] = hex_to_bin(str[16]) << 4 | hex_to_bin(str[17]); guid->b[7] = hex_to_bin(str[14]) << 4 | hex_to_bin(str[15]); guid->b[8] = hex_to_bin(str[19]) << 4 | hex_to_bin(str[20]); guid->b[9] = hex_to_bin(str[21]) << 4 | hex_to_bin(str[22]); guid->b[10] = hex_to_bin(str[24]) << 4 | hex_to_bin(str[25]); guid->b[11] = hex_to_bin(str[26]) << 4 | hex_to_bin(str[27]); guid->b[12] = hex_to_bin(str[28]) << 4 | hex_to_bin(str[29]); guid->b[13] = hex_to_bin(str[30]) << 4 | hex_to_bin(str[31]); guid->b[14] = hex_to_bin(str[32]) << 4 | hex_to_bin(str[33]); guid->b[15] = hex_to_bin(str[34]) << 4 | hex_to_bin(str[35]); } static int efivarfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl) { struct inode *inode; struct efivars *efivars = &__efivars; struct efivar_entry *var; int namelen, i = 0, err = 0; if (!efivarfs_valid_name(dentry->d_name.name, dentry->d_name.len)) return -EINVAL; inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0); if (!inode) return -ENOMEM; var = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL); if (!var) { err = -ENOMEM; goto out; } /* length of the variable name itself: remove GUID and separator */ namelen = dentry->d_name.len - GUID_LEN - 1; efivarfs_hex_to_guid(dentry->d_name.name + namelen + 1, &var->var.VendorGuid); for (i = 0; i < namelen; i++) var->var.VariableName[i] = dentry->d_name.name[i]; var->var.VariableName[i] = '\0'; inode->i_private = var; var->efivars = efivars; var->kobj.kset = efivars->kset; err = kobject_init_and_add(&var->kobj, &efivar_ktype, NULL, "%s", dentry->d_name.name); if (err) goto out; kobject_uevent(&var->kobj, KOBJ_ADD); spin_lock_irq(&efivars->lock); list_add(&var->list, &efivars->list); spin_unlock_irq(&efivars->lock); d_instantiate(dentry, inode); dget(dentry); out: if (err) { kfree(var); iput(inode); } return err; } static int efivarfs_unlink(struct inode *dir, struct dentry *dentry) { struct efivar_entry *var = dentry->d_inode->i_private; struct efivars *efivars = var->efivars; efi_status_t status; spin_lock_irq(&efivars->lock); status = efivars->ops->set_variable(var->var.VariableName, &var->var.VendorGuid, 0, 0, NULL); if (status == EFI_SUCCESS || status == EFI_NOT_FOUND) { list_del(&var->list); spin_unlock_irq(&efivars->lock); efivar_unregister(var); drop_nlink(dentry->d_inode); dput(dentry); return 0; } spin_unlock_irq(&efivars->lock); return -EINVAL; }; /* * Compare two efivarfs file names. * * An efivarfs filename is composed of two parts, * * 1. A case-sensitive variable name * 2. A case-insensitive GUID * * So we need to perform a case-sensitive match on part 1 and a * case-insensitive match on part 2. */ static int efivarfs_d_compare(const struct dentry *parent, const struct inode *pinode, const struct dentry *dentry, const struct inode *inode, unsigned int len, const char *str, const struct qstr *name) { int guid = len - GUID_LEN; if (name->len != len) return 1; /* Case-sensitive compare for the variable name */ if (memcmp(str, name->name, guid)) return 1; /* Case-insensitive compare for the GUID */ return strncasecmp(name->name + guid, str + guid, GUID_LEN); } static int efivarfs_d_hash(const struct dentry *dentry, const struct inode *inode, struct qstr *qstr) { unsigned long hash = init_name_hash(); const unsigned char *s = qstr->name; unsigned int len = qstr->len; if (!efivarfs_valid_name(s, len)) return -EINVAL; while (len-- > GUID_LEN) hash = partial_name_hash(*s++, hash); /* GUID is case-insensitive. */ while (len--) hash = partial_name_hash(tolower(*s++), hash); qstr->hash = end_name_hash(hash); return 0; } /* * Retaining negative dentries for an in-memory filesystem just wastes * memory and lookup time: arrange for them to be deleted immediately. */ static int efivarfs_delete_dentry(const struct dentry *dentry) { return 1; } static struct dentry_operations efivarfs_d_ops = { .d_compare = efivarfs_d_compare, .d_hash = efivarfs_d_hash, .d_delete = efivarfs_delete_dentry, }; static struct dentry *efivarfs_alloc_dentry(struct dentry *parent, char *name) { struct dentry *d; struct qstr q; int err; q.name = name; q.len = strlen(name); err = efivarfs_d_hash(NULL, NULL, &q); if (err) return ERR_PTR(err); d = d_alloc(parent, &q); if (d) return d; return ERR_PTR(-ENOMEM); } static int efivarfs_fill_super(struct super_block *sb, void *data, int silent) { struct inode *inode = NULL; struct dentry *root; struct efivar_entry *entry, *n; struct efivars *efivars = &__efivars; char *name; int err = -ENOMEM; efivarfs_sb = sb; sb->s_maxbytes = MAX_LFS_FILESIZE; sb->s_blocksize = PAGE_CACHE_SIZE; sb->s_blocksize_bits = PAGE_CACHE_SHIFT; sb->s_magic = EFIVARFS_MAGIC; sb->s_op = &efivarfs_ops; sb->s_d_op = &efivarfs_d_ops; sb->s_time_gran = 1; inode = efivarfs_get_inode(sb, NULL, S_IFDIR | 0755, 0); if (!inode) return -ENOMEM; inode->i_op = &efivarfs_dir_inode_operations; root = d_make_root(inode); sb->s_root = root; if (!root) return -ENOMEM; list_for_each_entry_safe(entry, n, &efivars->list, list) { struct dentry *dentry, *root = efivarfs_sb->s_root; unsigned long size = 0; int len, i; inode = NULL; len = utf16_strlen(entry->var.VariableName); /* name, plus '-', plus GUID, plus NUL*/ name = kmalloc(len + 1 + GUID_LEN + 1, GFP_ATOMIC); if (!name) goto fail; for (i = 0; i < len; i++) name[i] = entry->var.VariableName[i] & 0xFF; name[len] = '-'; efi_guid_unparse(&entry->var.VendorGuid, name + len + 1); name[len+GUID_LEN+1] = '\0'; inode = efivarfs_get_inode(efivarfs_sb, root->d_inode, S_IFREG | 0644, 0); if (!inode) goto fail_name; dentry = efivarfs_alloc_dentry(root, name); if (IS_ERR(dentry)) { err = PTR_ERR(dentry); goto fail_inode; } /* copied by the above to local storage in the dentry. */ kfree(name); spin_lock_irq(&efivars->lock); efivars->ops->get_variable(entry->var.VariableName, &entry->var.VendorGuid, &entry->var.Attributes, &size, NULL); spin_unlock_irq(&efivars->lock); mutex_lock(&inode->i_mutex); inode->i_private = entry; i_size_write(inode, size + sizeof(entry->var.Attributes)); mutex_unlock(&inode->i_mutex); d_add(dentry, inode); } return 0; fail_inode: iput(inode); fail_name: kfree(name); fail: return err; } static struct dentry *efivarfs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { return mount_single(fs_type, flags, data, efivarfs_fill_super); } static void efivarfs_kill_sb(struct super_block *sb) { kill_litter_super(sb); efivarfs_sb = NULL; } static struct file_system_type efivarfs_type = { .name = "efivarfs", .mount = efivarfs_mount, .kill_sb = efivarfs_kill_sb, }; MODULE_ALIAS_FS("efivarfs"); /* * Handle negative dentry. */ static struct dentry *efivarfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { if (dentry->d_name.len > NAME_MAX) return ERR_PTR(-ENAMETOOLONG); d_add(dentry, NULL); return NULL; } static const struct inode_operations efivarfs_dir_inode_operations = { .lookup = efivarfs_lookup, .unlink = efivarfs_unlink, .create = efivarfs_create, }; #ifdef CONFIG_EFI_VARS_PSTORE static int efi_pstore_open(struct pstore_info *psi) { struct efivars *efivars = psi->data; spin_lock_irq(&efivars->lock); efivars->walk_entry = list_first_entry(&efivars->list, struct efivar_entry, list); return 0; } static int efi_pstore_close(struct pstore_info *psi) { struct efivars *efivars = psi->data; spin_unlock_irq(&efivars->lock); return 0; } static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, int *count, struct timespec *timespec, char **buf, struct pstore_info *psi) { efi_guid_t vendor = LINUX_EFI_CRASH_GUID; struct efivars *efivars = psi->data; char name[DUMP_NAME_LEN]; int i; int cnt; unsigned int part, size; unsigned long time; while (&efivars->walk_entry->list != &efivars->list) { if (!efi_guidcmp(efivars->walk_entry->var.VendorGuid, vendor)) { for (i = 0; i < DUMP_NAME_LEN; i++) { name[i] = efivars->walk_entry->var.VariableName[i]; } if (sscanf(name, "dump-type%u-%u-%d-%lu", type, &part, &cnt, &time) == 4) { *id = part; *count = cnt; timespec->tv_sec = time; timespec->tv_nsec = 0; } else if (sscanf(name, "dump-type%u-%u-%lu", type, &part, &time) == 3) { /* * Check if an old format, * which doesn't support holding * multiple logs, remains. */ *id = part; *count = 0; timespec->tv_sec = time; timespec->tv_nsec = 0; } else { efivars->walk_entry = list_entry( efivars->walk_entry->list.next, struct efivar_entry, list); continue; } get_var_data_locked(efivars, &efivars->walk_entry->var); size = efivars->walk_entry->var.DataSize; *buf = kmalloc(size, GFP_KERNEL); if (*buf == NULL) return -ENOMEM; memcpy(*buf, efivars->walk_entry->var.Data, size); efivars->walk_entry = list_entry( efivars->walk_entry->list.next, struct efivar_entry, list); return size; } efivars->walk_entry = list_entry(efivars->walk_entry->list.next, struct efivar_entry, list); } return 0; } static int efi_pstore_write(enum pstore_type_id type, enum kmsg_dump_reason reason, u64 *id, unsigned int part, int count, size_t size, struct pstore_info *psi) { char name[DUMP_NAME_LEN]; efi_char16_t efi_name[DUMP_NAME_LEN]; efi_guid_t vendor = LINUX_EFI_CRASH_GUID; struct efivars *efivars = psi->data; int i, ret = 0; efi_status_t status = EFI_NOT_FOUND; unsigned long flags; if (pstore_cannot_block_path(reason)) { /* * If the lock is taken by another cpu in non-blocking path, * this driver returns without entering firmware to avoid * hanging up. */ if (!spin_trylock_irqsave(&efivars->lock, flags)) return -EBUSY; } else spin_lock_irqsave(&efivars->lock, flags); /* * Check if there is a space enough to log. * size: a size of logging data * DUMP_NAME_LEN * 2: a maximum size of variable name */ status = check_var_size_locked(efivars, PSTORE_EFI_ATTRIBUTES, size + DUMP_NAME_LEN * 2); if (status) { spin_unlock_irqrestore(&efivars->lock, flags); *id = part; return -ENOSPC; } sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count, get_seconds()); for (i = 0; i < DUMP_NAME_LEN; i++) efi_name[i] = name[i]; efivars->ops->set_variable(efi_name, &vendor, PSTORE_EFI_ATTRIBUTES, size, psi->buf); spin_unlock_irqrestore(&efivars->lock, flags); if (reason == KMSG_DUMP_OOPS && efivar_wq_enabled) schedule_work(&efivar_work); *id = part; return ret; }; static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count, struct timespec time, struct pstore_info *psi) { char name[DUMP_NAME_LEN]; efi_char16_t efi_name[DUMP_NAME_LEN]; char name_old[DUMP_NAME_LEN]; efi_char16_t efi_name_old[DUMP_NAME_LEN]; efi_guid_t vendor = LINUX_EFI_CRASH_GUID; struct efivars *efivars = psi->data; struct efivar_entry *entry, *found = NULL; int i; sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count, time.tv_sec); spin_lock_irq(&efivars->lock); for (i = 0; i < DUMP_NAME_LEN; i++) efi_name[i] = name[i]; /* * Clean up an entry with the same name */ list_for_each_entry(entry, &efivars->list, list) { get_var_data_locked(efivars, &entry->var); if (efi_guidcmp(entry->var.VendorGuid, vendor)) continue; if (utf16_strncmp(entry->var.VariableName, efi_name, utf16_strlen(efi_name))) { /* * Check if an old format, * which doesn't support holding * multiple logs, remains. */ sprintf(name_old, "dump-type%u-%u-%lu", type, (unsigned int)id, time.tv_sec); for (i = 0; i < DUMP_NAME_LEN; i++) efi_name_old[i] = name_old[i]; if (utf16_strncmp(entry->var.VariableName, efi_name_old, utf16_strlen(efi_name_old))) continue; } /* found */ found = entry; efivars->ops->set_variable(entry->var.VariableName, &entry->var.VendorGuid, PSTORE_EFI_ATTRIBUTES, 0, NULL); break; } if (found) list_del(&found->list); spin_unlock_irq(&efivars->lock); if (found) efivar_unregister(found); return 0; } static struct pstore_info efi_pstore_info = { .owner = THIS_MODULE, .name = "efi", .open = efi_pstore_open, .close = efi_pstore_close, .read = efi_pstore_read, .write = efi_pstore_write, .erase = efi_pstore_erase, }; static void efivar_pstore_register(struct efivars *efivars) { efivars->efi_pstore_info = efi_pstore_info; efivars->efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL); if (efivars->efi_pstore_info.buf) { efivars->efi_pstore_info.bufsize = 1024; efivars->efi_pstore_info.data = efivars; spin_lock_init(&efivars->efi_pstore_info.buf_lock); pstore_register(&efivars->efi_pstore_info); } } #else static void efivar_pstore_register(struct efivars *efivars) { return; } #endif 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 efi_variable *new_var = (struct efi_variable *)buf; struct efivars *efivars = bin_attr->private; struct efivar_entry *search_efivar, *n; unsigned long strsize1, strsize2; efi_status_t status = EFI_NOT_FOUND; int found = 0; if (!capable(CAP_SYS_ADMIN)) return -EACCES; if ((new_var->Attributes & ~EFI_VARIABLE_MASK) != 0 || validate_var(new_var, new_var->Data, new_var->DataSize) == false) { printk(KERN_ERR "efivars: Malformed variable content\n"); return -EINVAL; } spin_lock_irq(&efivars->lock); /* * Does this variable already exist? */ list_for_each_entry_safe(search_efivar, n, &efivars->list, list) { strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024); strsize2 = utf16_strsize(new_var->VariableName, 1024); if (strsize1 == strsize2 && !memcmp(&(search_efivar->var.VariableName), new_var->VariableName, strsize1) && !efi_guidcmp(search_efivar->var.VendorGuid, new_var->VendorGuid)) { found = 1; break; } } if (found) { spin_unlock_irq(&efivars->lock); return -EINVAL; } status = check_var_size_locked(efivars, new_var->Attributes, new_var->DataSize + utf16_strsize(new_var->VariableName, 1024)); if (status && status != EFI_UNSUPPORTED) { spin_unlock_irq(&efivars->lock); return efi_status_to_err(status); } /* now *really* create the variable via EFI */ status = efivars->ops->set_variable(new_var->VariableName, &new_var->VendorGuid, new_var->Attributes, new_var->DataSize, new_var->Data); if (status != EFI_SUCCESS) { printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n", status); spin_unlock_irq(&efivars->lock); return -EIO; } spin_unlock_irq(&efivars->lock); /* Create the entry in sysfs. Locking is not required here */ status = efivar_create_sysfs_entry(efivars, utf16_strsize(new_var->VariableName, 1024), new_var->VariableName, &new_var->VendorGuid); if (status) { printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n"); } return count; } 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 efivars *efivars = bin_attr->private; struct efivar_entry *search_efivar, *n; unsigned long strsize1, strsize2; efi_status_t status = EFI_NOT_FOUND; int found = 0; if (!capable(CAP_SYS_ADMIN)) return -EACCES; spin_lock_irq(&efivars->lock); /* * Does this variable already exist? */ list_for_each_entry_safe(search_efivar, n, &efivars->list, list) { strsize1 = utf16_strsize(search_efivar->var.VariableName, 1024); strsize2 = utf16_strsize(del_var->VariableName, 1024); if (strsize1 == strsize2 && !memcmp(&(search_efivar->var.VariableName), del_var->VariableName, strsize1) && !efi_guidcmp(search_efivar->var.VendorGuid, del_var->VendorGuid)) { found = 1; break; } } if (!found) { spin_unlock_irq(&efivars->lock); return -EINVAL; } /* force the Attributes/DataSize to 0 to ensure deletion */ del_var->Attributes = 0; del_var->DataSize = 0; status = efivars->ops->set_variable(del_var->VariableName, &del_var->VendorGuid, del_var->Attributes, del_var->DataSize, del_var->Data); if (status != EFI_SUCCESS) { printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n", status); spin_unlock_irq(&efivars->lock); return -EIO; } list_del(&search_efivar->list); /* We need to release this lock before unregistering. */ spin_unlock_irq(&efivars->lock); efivar_unregister(search_efivar); /* It's dead Jim.... */ return count; } static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor) { struct efivar_entry *entry, *n; struct efivars *efivars = &__efivars; unsigned long strsize1, strsize2; bool found = false; strsize1 = utf16_strsize(variable_name, 1024); list_for_each_entry_safe(entry, n, &efivars->list, list) { strsize2 = utf16_strsize(entry->var.VariableName, 1024); if (strsize1 == strsize2 && !memcmp(variable_name, &(entry->var.VariableName), strsize2) && !efi_guidcmp(entry->var.VendorGuid, *vendor)) { found = true; break; } } return found; } /* * Returns the size of variable_name, in bytes, including the * terminating NULL character, or variable_name_size if no NULL * character is found among the first variable_name_size bytes. */ static unsigned long var_name_strnsize(efi_char16_t *variable_name, unsigned long variable_name_size) { unsigned long len; efi_char16_t c; /* * The variable name is, by definition, a NULL-terminated * string, so make absolutely sure that variable_name_size is * the value we expect it to be. If not, return the real size. */ for (len = 2; len <= variable_name_size; len += sizeof(c)) { c = variable_name[(len / sizeof(c)) - 1]; if (!c) break; } return min(len, variable_name_size); } static void efivar_update_sysfs_entries(struct work_struct *work) { struct efivars *efivars = &__efivars; efi_guid_t vendor; efi_char16_t *variable_name; unsigned long variable_name_size = 1024; efi_status_t status = EFI_NOT_FOUND; bool found; /* Add new sysfs entries */ while (1) { variable_name = kzalloc(variable_name_size, GFP_KERNEL); if (!variable_name) { pr_err("efivars: Memory allocation failed.\n"); return; } spin_lock_irq(&efivars->lock); found = false; while (1) { variable_name_size = 1024; status = efivars->ops->get_next_variable( &variable_name_size, variable_name, &vendor); if (status != EFI_SUCCESS) { break; } else { if (!variable_is_present(variable_name, &vendor)) { found = true; break; } } } spin_unlock_irq(&efivars->lock); if (!found) { kfree(variable_name); break; } else { variable_name_size = var_name_strnsize(variable_name, variable_name_size); efivar_create_sysfs_entry(efivars, variable_name_size, variable_name, &vendor); } } } /* * Let's not leave out systab information that snuck into * the efivars driver */ static ssize_t systab_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { char *str = buf; if (!kobj || !buf) return -EINVAL; if (efi.mps != EFI_INVALID_TABLE_ADDR) str += sprintf(str, "MPS=0x%lx\n", efi.mps); if (efi.acpi20 != EFI_INVALID_TABLE_ADDR) str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20); if (efi.acpi != EFI_INVALID_TABLE_ADDR) str += sprintf(str, "ACPI=0x%lx\n", efi.acpi); if (efi.smbios != EFI_INVALID_TABLE_ADDR) str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios); if (efi.hcdp != EFI_INVALID_TABLE_ADDR) str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp); if (efi.boot_info != EFI_INVALID_TABLE_ADDR) str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info); if (efi.uga != EFI_INVALID_TABLE_ADDR) str += sprintf(str, "UGA=0x%lx\n", efi.uga); return str - buf; } static struct kobj_attribute efi_attr_systab = __ATTR(systab, 0400, systab_show, NULL); static struct attribute *efi_subsys_attrs[] = { &efi_attr_systab.attr, NULL, /* maybe more in the future? */ }; static struct attribute_group efi_subsys_attr_group = { .attrs = efi_subsys_attrs, }; static struct kobject *efi_kobj; /* * efivar_create_sysfs_entry() * Requires: * variable_name_size = number of bytes required to hold * variable_name (not counting the NULL * character at the end. * efivars->lock is not held on entry or exit. * Returns 1 on failure, 0 on success */ static int efivar_create_sysfs_entry(struct efivars *efivars, unsigned long variable_name_size, efi_char16_t *variable_name, efi_guid_t *vendor_guid) { int i, short_name_size; char *short_name; struct efivar_entry *new_efivar; /* * Length of the variable bytes in ASCII, plus the '-' separator, * plus the GUID, plus trailing NUL */ short_name_size = variable_name_size / sizeof(efi_char16_t) + 1 + GUID_LEN + 1; short_name = kzalloc(short_name_size, GFP_KERNEL); new_efivar = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL); if (!short_name || !new_efivar) { kfree(short_name); kfree(new_efivar); return 1; } new_efivar->efivars = efivars; memcpy(new_efivar->var.VariableName, variable_name, variable_name_size); memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t)); /* Convert Unicode to normal chars (assume top bits are 0), ala UTF-8 */ for (i=0; i < (int)(variable_name_size / sizeof(efi_char16_t)); i++) { short_name[i] = variable_name[i] & 0xFF; } /* This is ugly, but necessary to separate one vendor's private variables from another's. */ *(short_name + strlen(short_name)) = '-'; efi_guid_unparse(vendor_guid, short_name + strlen(short_name)); new_efivar->kobj.kset = efivars->kset; i = kobject_init_and_add(&new_efivar->kobj, &efivar_ktype, NULL, "%s", short_name); if (i) { kfree(short_name); kfree(new_efivar); return 1; } kobject_uevent(&new_efivar->kobj, KOBJ_ADD); kfree(short_name); short_name = NULL; spin_lock_irq(&efivars->lock); list_add(&new_efivar->list, &efivars->list); spin_unlock_irq(&efivars->lock); return 0; } static int create_efivars_bin_attributes(struct efivars *efivars) { 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; attr->private = efivars; 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; attr->private = efivars; 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; } void unregister_efivars(struct efivars *efivars) { struct efivar_entry *entry, *n; list_for_each_entry_safe(entry, n, &efivars->list, list) { spin_lock_irq(&efivars->lock); list_del(&entry->list); spin_unlock_irq(&efivars->lock); efivar_unregister(entry); } 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); kobject_put(efivars->kobject); kset_unregister(efivars->kset); } EXPORT_SYMBOL_GPL(unregister_efivars); /* * Print a warning when duplicate EFI variables are encountered and * disable the sysfs workqueue since the firmware is buggy. */ static void dup_variable_bug(efi_char16_t *s16, efi_guid_t *vendor_guid, unsigned long len16) { size_t i, len8 = len16 / sizeof(efi_char16_t); char *s8; /* * Disable the workqueue since the algorithm it uses for * detecting new variables won't work with this buggy * implementation of GetNextVariableName(). */ efivar_wq_enabled = false; s8 = kzalloc(len8, GFP_KERNEL); if (!s8) return; for (i = 0; i < len8; i++) s8[i] = s16[i]; printk(KERN_WARNING "efivars: duplicate variable: %s-%pUl\n", s8, vendor_guid); kfree(s8); } int register_efivars(struct efivars *efivars, const struct efivar_operations *ops, struct kobject *parent_kobj) { efi_status_t status = EFI_NOT_FOUND; efi_guid_t vendor_guid; efi_char16_t *variable_name; unsigned long variable_name_size = 1024; int error = 0; variable_name = kzalloc(variable_name_size, GFP_KERNEL); if (!variable_name) { printk(KERN_ERR "efivars: Memory allocation failed.\n"); return -ENOMEM; } spin_lock_init(&efivars->lock); INIT_LIST_HEAD(&efivars->list); efivars->ops = ops; efivars->kset = kset_create_and_add("vars", NULL, parent_kobj); if (!efivars->kset) { printk(KERN_ERR "efivars: Subsystem registration failed.\n"); error = -ENOMEM; goto out; } efivars->kobject = kobject_create_and_add("efivars", parent_kobj); if (!efivars->kobject) { pr_err("efivars: Subsystem registration failed.\n"); error = -ENOMEM; kset_unregister(efivars->kset); goto out; } /* * Per EFI spec, the maximum storage allocated for both * the variable name and variable data is 1024 bytes. */ do { variable_name_size = 1024; status = ops->get_next_variable(&variable_name_size, variable_name, &vendor_guid); switch (status) { case EFI_SUCCESS: variable_name_size = var_name_strnsize(variable_name, variable_name_size); /* * Some firmware implementations return the * same variable name on multiple calls to * get_next_variable(). Terminate the loop * immediately as there is no guarantee that * we'll ever see a different variable name, * and may end up looping here forever. */ if (variable_is_present(variable_name, &vendor_guid)) { dup_variable_bug(variable_name, &vendor_guid, variable_name_size); status = EFI_NOT_FOUND; break; } efivar_create_sysfs_entry(efivars, variable_name_size, variable_name, &vendor_guid); break; case EFI_NOT_FOUND: break; default: printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n", status); status = EFI_NOT_FOUND; break; } } while (status != EFI_NOT_FOUND); error = create_efivars_bin_attributes(efivars); if (error) unregister_efivars(efivars); if (!efivars_pstore_disable) efivar_pstore_register(efivars); register_filesystem(&efivarfs_type); out: kfree(variable_name); return error; } EXPORT_SYMBOL_GPL(register_efivars); /* * For now we register the efi subsystem with the firmware subsystem * and the vars subsystem with the efi subsystem. In the future, it * might make sense to split off the efi subsystem into its own * driver, but for now only efivars will register with it, so just * include it here. */ static int __init efivars_init(void) { int error = 0; printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION, EFIVARS_DATE); if (!efi_enabled(EFI_RUNTIME_SERVICES)) return 0; /* For now we'll register the efi directory at /sys/firmware/efi */ efi_kobj = kobject_create_and_add("efi", firmware_kobj); if (!efi_kobj) { printk(KERN_ERR "efivars: Firmware registration failed.\n"); return -ENOMEM; } ops.get_variable = efi.get_variable; ops.set_variable = efi.set_variable; ops.get_next_variable = efi.get_next_variable; ops.query_variable_info = efi.query_variable_info; error = register_efivars(&__efivars, &ops, efi_kobj); if (error) goto err_put; /* Don't forget the systab entry */ error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group); if (error) { printk(KERN_ERR "efivars: Sysfs attribute export failed with error %d.\n", error); goto err_unregister; } return 0; err_unregister: unregister_efivars(&__efivars); err_put: kobject_put(efi_kobj); return error; } static void __exit efivars_exit(void) { cancel_work_sync(&efivar_work); if (efi_enabled(EFI_RUNTIME_SERVICES)) { unregister_efivars(&__efivars); kobject_put(efi_kobj); } } module_init(efivars_init); module_exit(efivars_exit);