Orange Pi5 kernel

// 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,
};
 
static struct kobj_type efivar_ktype = {
<------>.release = efivar_release,
<------>.sysfs_ops = &efivar_attr_ops,
<------>.default_attrs = def_attrs,
};
 
static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
<------><------><------>     struct bin_attribute *bin_attr,
<------><------><------>     char *buf, loff_t pos, size_t count)
{
<------>struct compat_efi_variable *compat = (struct compat_efi_variable *)buf;
<------>struct efi_variable *new_var = (struct efi_variable *)buf;
<------>struct efivar_entry *new_entry;
<------>bool need_compat = 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;
 
<------>if (err) {
<------><------>efivar_entry_iter_end();
<------><------>return err;
<------>}
 
<------>if (!entry->scanning) {
<------><------>efivar_entry_iter_end();
<------><------>efivar_unregister(entry);
<------>} else
<------><------>efivar_entry_iter_end();
 
<------>/* It's dead Jim.... */
<------>return count;
}
 
/**
 * efivar_create_sysfs_entry - create a new entry in sysfs
 * @new_var: efivar entry to create
 *
 * Returns 0 on success, negative error code on failure
 */
static int
efivar_create_sysfs_entry(struct efivar_entry *new_var)
{
<------>int short_name_size;
<------>char *short_name;
<------>unsigned long utf8_name_size;
<------>efi_char16_t *variable_name = new_var->var.VariableName;
<------>int ret;
 
<------>/*
<------> * Length of the variable bytes in UTF8, plus the '-' separator,
<------> * plus the GUID, plus trailing NUL
<------> */
<------>utf8_name_size = ucs2_utf8size(variable_name);
<------>short_name_size = utf8_name_size + 1 + EFI_VARIABLE_GUID_LEN + 1;
 
<------>short_name = kmalloc(short_name_size, GFP_KERNEL);
<------>if (!short_name)
<------><------>return -ENOMEM;
 
<------>ucs2_as_utf8(short_name, variable_name, short_name_size);
 
<------>/* This is ugly, but necessary to separate one vendor's
<------>   private variables from another's.         */
<------>short_name[utf8_name_size] = '-';
<------>efi_guid_to_str(&new_var->var.VendorGuid,
<------><------><------> short_name + utf8_name_size + 1);
 
<------>new_var->kobj.kset = efivars_kset;
 
<------>ret = kobject_init_and_add(&new_var->kobj, &efivar_ktype,
<------><------><------><------>   NULL, "%s", short_name);
<------>kfree(short_name);
<------>if (ret) {
<------><------>kobject_put(&new_var->kobj);
<------><------>return ret;
<------>}
 
<------>kobject_uevent(&new_var->kobj, KOBJ_ADD);
<------>if (efivar_entry_add(new_var, &efivar_sysfs_list)) {
<------><------>efivar_unregister(new_var);
<------><------>return -EINTR;
<------>}
 
<------>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)
{
<------>int err = efivar_entry_remove(entry);
 
<------>if (err)
<------><------>return err;
<------>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, 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);