+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * Originally from efivars.c,
- *
- * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
- * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
- *
- * This code takes all variables accessible from EFI runtime and
- * exports them via sysfs
- */
-
-#include <linux/efi.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/ucs2_string.h>
-#include <linux/compat.h>
-
-#define EFIVARS_VERSION "0.08"
-#define EFIVARS_DATE "2004-May-17"
-
-MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
-MODULE_DESCRIPTION("sysfs interface to EFI Variables");
-MODULE_LICENSE("GPL");
-MODULE_VERSION(EFIVARS_VERSION);
-
-static LIST_HEAD(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 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 (in_compat_syscall()) {
- 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 (in_compat_syscall()) {
- 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 = to_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,
-};
-ATTRIBUTE_GROUPS(def);
-
-static struct kobj_type efivar_ktype = {
- .release = efivar_release,
- .sysfs_ops = &efivar_attr_ops,
- .default_groups = def_groups,
-};
-
-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 = in_compat_syscall();
- 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 (in_compat_syscall()) {
- 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;
- }
-
- if (efivar_entry_iter_begin())
- return -EINTR;
- entry = efivar_entry_find(name, vendor, &efivar_sysfs_list, true);
- if (!entry)
- err = -EINVAL;
- else if (__efivar_entry_delete(entry))
- err = -EIO;
-
- efivar_entry_iter_end();
-
- if (err)
- return err;
-
- efivar_unregister(entry);
-
- /* 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 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 */
- int err;
-
- err = efivar_entry_iter(efivar_sysfs_destroy, &efivar_sysfs_list, NULL);
- if (err) {
- pr_err("efivars: Failed to destroy sysfs entries\n");
- return;
- }
-
- 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);
-}
-
-static int efivars_sysfs_init(void)
-{
- struct kobject *parent_kobj = efivars_kobject();
- int error = 0;
-
- /* No efivars has been registered yet */
- if (!parent_kobj || !efivar_supports_writes())
- 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, true, &efivar_sysfs_list);
-
- error = create_efivars_bin_attributes();
- if (error) {
- efivars_sysfs_exit();
- return error;
- }
-
- return 0;
-}
-
-module_init(efivars_sysfs_init);
-module_exit(efivars_sysfs_exit);
up(&efivars_lock);
}
-/**
- * __efivar_entry_delete - delete an EFI variable
- * @entry: entry containing EFI variable to delete
- *
- * Delete the variable from the firmware but leave @entry on the
- * variable list.
- *
- * This function differs from efivar_entry_delete() because it does
- * not remove @entry from the variable list. Also, it is safe to be
- * called from within a efivar_entry_iter_begin() and
- * efivar_entry_iter_end() region, unlike efivar_entry_delete().
- *
- * Returns 0 on success, or a converted EFI status code if
- * set_variable() fails.
- */
-int __efivar_entry_delete(struct efivar_entry *entry)
-{
- efi_status_t status;
-
- if (!__efivars)
- return -EINVAL;
-
- status = __efivars->ops->set_variable(entry->var.VariableName,
- &entry->var.VendorGuid,
- 0, 0, NULL);
-
- return efi_status_to_err(status);
-}
-EXPORT_SYMBOL_GPL(__efivar_entry_delete);
-
/**
* efivar_entry_delete - delete variable and remove entry from list
* @entry: entry containing variable to delete
}
EXPORT_SYMBOL_GPL(efivar_entry_delete);
-/**
- * efivar_entry_set - call set_variable()
- * @entry: entry containing the EFI variable to write
- * @attributes: variable attributes
- * @size: size of @data buffer
- * @data: buffer containing variable data
- * @head: head of variable list
- *
- * Calls set_variable() for an EFI variable. If creating a new EFI
- * variable, this function is usually followed by efivar_entry_add().
- *
- * Before writing the variable, the remaining EFI variable storage
- * space is checked to ensure there is enough room available.
- *
- * If @head is not NULL a lookup is performed to determine whether
- * the entry is already on the list.
- *
- * Returns 0 on success, -EINTR if we can't grab the semaphore,
- * -EEXIST if a lookup is performed and the entry already exists on
- * the list, or a converted EFI status code if set_variable() fails.
- */
-int efivar_entry_set(struct efivar_entry *entry, u32 attributes,
- unsigned long size, void *data, struct list_head *head)
-{
- const struct efivar_operations *ops;
- efi_status_t status;
- efi_char16_t *name = entry->var.VariableName;
- efi_guid_t vendor = entry->var.VendorGuid;
-
- if (down_interruptible(&efivars_lock))
- return -EINTR;
-
- if (!__efivars) {
- up(&efivars_lock);
- return -EINVAL;
- }
- ops = __efivars->ops;
- if (head && efivar_entry_find(name, vendor, head, false)) {
- up(&efivars_lock);
- return -EEXIST;
- }
-
- status = check_var_size(attributes, size + ucs2_strsize(name, 1024));
- if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED)
- status = ops->set_variable(name, &vendor,
- attributes, size, data);
-
- up(&efivars_lock);
-
- return efi_status_to_err(status);
-
-}
-EXPORT_SYMBOL_GPL(efivar_entry_set);
-
-/*
- * efivar_entry_set_nonblocking - call set_variable_nonblocking()
- *
- * This function is guaranteed to not block and is suitable for calling
- * from crash/panic handlers.
- *
- * Crucially, this function will not block if it cannot acquire
- * efivars_lock. Instead, it returns -EBUSY.
- */
-static int
-efivar_entry_set_nonblocking(efi_char16_t *name, efi_guid_t vendor,
- u32 attributes, unsigned long size, void *data)
-{
- const struct efivar_operations *ops;
- efi_status_t status;
-
- if (down_trylock(&efivars_lock))
- return -EBUSY;
-
- if (!__efivars) {
- up(&efivars_lock);
- return -EINVAL;
- }
-
- status = check_var_size_nonblocking(attributes,
- size + ucs2_strsize(name, 1024));
- if (status != EFI_SUCCESS) {
- up(&efivars_lock);
- return -ENOSPC;
- }
-
- ops = __efivars->ops;
- status = ops->set_variable_nonblocking(name, &vendor, attributes,
- size, data);
-
- up(&efivars_lock);
- return efi_status_to_err(status);
-}
-
-/**
- * efivar_entry_set_safe - call set_variable() if enough space in firmware
- * @name: buffer containing the variable name
- * @vendor: variable vendor guid
- * @attributes: variable attributes
- * @block: can we block in this context?
- * @size: size of @data buffer
- * @data: buffer containing variable data
- *
- * Ensures there is enough free storage in the firmware for this variable, and
- * if so, calls set_variable(). If creating a new EFI variable, this function
- * is usually followed by efivar_entry_add().
- *
- * Returns 0 on success, -ENOSPC if the firmware does not have enough
- * space for set_variable() to succeed, or a converted EFI status code
- * if set_variable() fails.
- */
-int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes,
- bool block, unsigned long size, void *data)
-{
- const struct efivar_operations *ops;
- efi_status_t status;
- unsigned long varsize;
-
- if (!__efivars)
- return -EINVAL;
-
- ops = __efivars->ops;
- if (!ops->query_variable_store)
- return -ENOSYS;
-
- /*
- * If the EFI variable backend provides a non-blocking
- * ->set_variable() operation and we're in a context where we
- * cannot block, then we need to use it to avoid live-locks,
- * since the implication is that the regular ->set_variable()
- * will block.
- *
- * If no ->set_variable_nonblocking() is provided then
- * ->set_variable() is assumed to be non-blocking.
- */
- if (!block && ops->set_variable_nonblocking)
- return efivar_entry_set_nonblocking(name, vendor, attributes,
- size, data);
-
- varsize = size + ucs2_strsize(name, 1024);
- if (!block) {
- if (down_trylock(&efivars_lock))
- return -EBUSY;
- status = check_var_size_nonblocking(attributes, varsize);
- } else {
- if (down_interruptible(&efivars_lock))
- return -EINTR;
- status = check_var_size(attributes, varsize);
- }
-
- if (status != EFI_SUCCESS) {
- up(&efivars_lock);
- return -ENOSPC;
- }
-
- status = ops->set_variable(name, &vendor, attributes, size, data);
-
- up(&efivars_lock);
-
- return efi_status_to_err(status);
-}
-EXPORT_SYMBOL_GPL(efivar_entry_set_safe);
-
-/**
- * efivar_entry_find - search for an entry
- * @name: the EFI variable name
- * @guid: the EFI variable vendor's guid
- * @head: head of the variable list
- * @remove: should we remove the entry from the list?
- *
- * Search for an entry on the variable list that has the EFI variable
- * name @name and vendor guid @guid. If an entry is found on the list
- * and @remove is true, the entry is removed from the list.
- *
- * The caller MUST call efivar_entry_iter_begin() and
- * efivar_entry_iter_end() before and after the invocation of this
- * function, respectively.
- *
- * Returns the entry if found on the list, %NULL otherwise.
- */
-struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid,
- struct list_head *head, bool remove)
-{
- struct efivar_entry *entry, *n;
- int strsize1, strsize2;
- bool found = false;
-
- list_for_each_entry_safe(entry, n, head, list) {
- strsize1 = ucs2_strsize(name, 1024);
- strsize2 = ucs2_strsize(entry->var.VariableName, 1024);
- if (strsize1 == strsize2 &&
- !memcmp(name, &(entry->var.VariableName), strsize1) &&
- !efi_guidcmp(guid, entry->var.VendorGuid)) {
- found = true;
- break;
- }
- }
-
- if (!found)
- return NULL;
-
- if (remove)
- list_del(&entry->list);
-
- return entry;
-}
-EXPORT_SYMBOL_GPL(efivar_entry_find);
-
/**
* efivar_entry_size - obtain the size of a variable
* @entry: entry for this variable
}
EXPORT_SYMBOL_GPL(efivar_entry_set_get_size);
-/**
- * efivar_entry_iter_begin - begin iterating the variable list
- *
- * Lock the variable list to prevent entry insertion and removal until
- * efivar_entry_iter_end() is called. This function is usually used in
- * conjunction with __efivar_entry_iter() or efivar_entry_iter().
- */
-int efivar_entry_iter_begin(void)
-{
- return down_interruptible(&efivars_lock);
-}
-EXPORT_SYMBOL_GPL(efivar_entry_iter_begin);
-
-/**
- * efivar_entry_iter_end - finish iterating the variable list
- *
- * Unlock the variable list and allow modifications to the list again.
- */
-void efivar_entry_iter_end(void)
-{
- up(&efivars_lock);
-}
-EXPORT_SYMBOL_GPL(efivar_entry_iter_end);
-
/**
* efivar_entry_iter - iterate over variable list
* @func: callback function
struct efivar_entry *entry, *n;
int err = 0;
- err = efivar_entry_iter_begin();
+ err = down_interruptible(&efivars_lock);
if (err)
return err;
if (err)
break;
}
- efivar_entry_iter_end();
+ up(&efivars_lock);
return err;
}
projects / users / jedix / linux-maple.git / commitdiff