/* * 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 #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 /* * 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); }; #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); /* 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; spin_lock(&efivars->lock); status = get_var_data_locked(efivars, var); spin_unlock(&efivars->lock); if (status != EFI_SUCCESS) { printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n", status); } 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(&efivars->lock); status = efivars->ops->set_variable(new_var->VariableName, &new_var->VendorGuid, new_var->Attributes, new_var->DataSize, new_var->Data); spin_unlock(&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 struct pstore_info efi_pstore_info; static inline void efivar_unregister(struct efivar_entry *var) { kobject_put(&var->kobj); } #ifdef CONFIG_PSTORE static int efi_pstore_open(struct pstore_info *psi) { struct efivars *efivars = psi->data; spin_lock(&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(&efivars->lock); return 0; } static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, 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; 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-%lu", type, &part, &time) == 3) { *id = part; timespec->tv_sec = time; timespec->tv_nsec = 0; 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, size_t size, struct pstore_info *psi) { char name[DUMP_NAME_LEN]; char stub_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; struct efivar_entry *entry, *found = NULL; int i, ret = 0; u64 storage_space, remaining_space, max_variable_size; efi_status_t status = EFI_NOT_FOUND; sprintf(stub_name, "dump-type%u-%u-", type, part); sprintf(name, "%s%lu", stub_name, get_seconds()); spin_lock(&efivars->lock); /* * 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 = efivars->ops->query_variable_info(PSTORE_EFI_ATTRIBUTES, &storage_space, &remaining_space, &max_variable_size); if (status || remaining_space < size + DUMP_NAME_LEN * 2) { spin_unlock(&efivars->lock); *id = part; return -ENOSPC; } for (i = 0; i < DUMP_NAME_LEN; i++) efi_name[i] = stub_name[i]; /* * Clean up any entries 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))) continue; /* Needs to be a prefix */ if (entry->var.VariableName[utf16_strlen(efi_name)] == 0) continue; /* found */ found = entry; efivars->ops->set_variable(entry->var.VariableName, &entry->var.VendorGuid, PSTORE_EFI_ATTRIBUTES, 0, NULL); } if (found) list_del(&found->list); 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(&efivars->lock); if (found) efivar_unregister(found); if (size) ret = efivar_create_sysfs_entry(efivars, utf16_strsize(efi_name, DUMP_NAME_LEN * 2), efi_name, &vendor); *id = part; return ret; }; static int efi_pstore_erase(enum pstore_type_id type, u64 id, struct pstore_info *psi) { char stub_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; struct efivar_entry *entry, *found = NULL; int i; sprintf(stub_name, "dump-type%u-%u-", type, (unsigned int)id); spin_lock(&efivars->lock); for (i = 0; i < DUMP_NAME_LEN; i++) efi_name[i] = stub_name[i]; /* * Clean up any entries 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))) continue; /* Needs to be a prefix */ if (entry->var.VariableName[utf16_strlen(efi_name)] == 0) continue; /* found */ found = entry; efivars->ops->set_variable(entry->var.VariableName, &entry->var.VendorGuid, PSTORE_EFI_ATTRIBUTES, 0, NULL); } if (found) list_del(&found->list); spin_unlock(&efivars->lock); if (found) efivar_unregister(found); return 0; } #else static int efi_pstore_open(struct pstore_info *psi) { return 0; } static int efi_pstore_close(struct pstore_info *psi) { return 0; } static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type, struct timespec *timespec, char **buf, struct pstore_info *psi) { return -1; } static int efi_pstore_write(enum pstore_type_id type, enum kmsg_dump_reason reason, u64 *id, unsigned int part, size_t size, struct pstore_info *psi) { return 0; } static int efi_pstore_erase(enum pstore_type_id type, u64 id, struct pstore_info *psi) { return 0; } #endif 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 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(&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(&efivars->lock); return -EINVAL; } /* 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(&efivars->lock); return -EIO; } spin_unlock(&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(&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(&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(&efivars->lock); return -EIO; } list_del(&search_efivar->list); /* We need to release this lock before unregistering. */ spin_unlock(&efivars->lock); efivar_unregister(search_efivar); /* It's dead Jim.... */ return count; } /* * 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 = variable_name_size / sizeof(efi_char16_t) + 38; char *short_name; struct efivar_entry *new_efivar; short_name = kzalloc(short_name_size + 1, 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(&efivars->lock); list_add(&new_efivar->list, &efivars->list); spin_unlock(&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(&efivars->lock); list_del(&entry->list); spin_unlock(&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); kset_unregister(efivars->kset); } EXPORT_SYMBOL_GPL(unregister_efivars); 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; } /* * 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: 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); 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); } out: kfree(variable_name); return error; } EXPORT_SYMBOL_GPL(register_efivars); static struct efivars __efivars; static struct efivar_operations ops; /* * 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) 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) { if (efi_enabled) { unregister_efivars(&__efivars); kobject_put(efi_kobj); } } module_init(efivars_init); module_exit(efivars_exit);