#include <linux/slab.h>
#include <linux/pstore.h>
+#include <linux/fs.h>
+#include <linux/ramfs.h>
+#include <linux/pagemap.h>
+
#include <asm/uaccess.h>
#define EFIVARS_VERSION "0.08"
#define DUMP_NAME_LEN 52
+/*
+ * Length of a GUID string (strlen("aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee"))
+ * not including trailing NUL
+ */
+#define GUID_LEN 36
+
/*
* The maximum size of VariableName + Data = 1024
* Therefore, it's reasonable to save that much
__u32 Attributes;
} __attribute__((packed));
-
struct efivar_entry {
struct efivars *efivars;
struct efi_variable var;
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 | \
.default_attrs = def_attrs,
};
-static struct pstore_info efi_pstore_info;
-
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 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;
+ int datasize = count - sizeof(attributes);
+ unsigned long newdatasize;
+
+ if (count < sizeof(attributes))
+ return -EINVAL;
+
+ data = kmalloc(datasize, GFP_KERNEL);
+
+ if (!data)
+ return -ENOMEM;
+
+ efivars = var->efivars;
+
+ if (copy_from_user(&attributes, userbuf, sizeof(attributes))) {
+ count = -EFAULT;
+ goto out;
+ }
+
+ if (attributes & ~(EFI_VARIABLE_MASK)) {
+ count = -EINVAL;
+ goto out;
+ }
+
+ if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) {
+ count = -EFAULT;
+ goto out;
+ }
+
+ if (validate_var(&var->var, data, datasize) == false) {
+ count = -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(&efivars->lock);
+
+ status = efivars->ops->set_variable(var->var.VariableName,
+ &var->var.VendorGuid,
+ attributes, datasize,
+ data);
+
+ if (status != EFI_SUCCESS) {
+ spin_unlock(&efivars->lock);
+ kfree(data);
+
+ switch (status) {
+ case EFI_INVALID_PARAMETER:
+ count = -EINVAL;
+ break;
+ case EFI_OUT_OF_RESOURCES:
+ count = -ENOSPC;
+ break;
+ case EFI_DEVICE_ERROR:
+ count = -EIO;
+ break;
+ case EFI_WRITE_PROTECTED:
+ count = -EROFS;
+ break;
+ case EFI_SECURITY_VIOLATION:
+ count = -EACCES;
+ break;
+ case EFI_NOT_FOUND:
+ count = -ENOENT;
+ break;
+ default:
+ count = -EINVAL;
+ }
+ return 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(&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(&efivars->lock);
+ efivar_unregister(var);
+ drop_nlink(inode);
+ dput(file->f_dentry);
+
+ } else {
+ spin_unlock(&efivars->lock);
+ pr_warn("efivarfs: inconsistent EFI variable implementation? "
+ "status = %lx\n", status);
+ }
+
+out:
+ kfree(data);
+
+ return count;
+}
+
+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(&efivars->lock);
+ status = efivars->ops->get_variable(var->var.VariableName,
+ &var->var.VendorGuid,
+ &attributes, &datasize, NULL);
+ spin_unlock(&efivars->lock);
+
+ if (status != EFI_BUFFER_TOO_SMALL)
+ return 0;
+
+ data = kmalloc(datasize + 4, GFP_KERNEL);
+
+ if (!data)
+ return 0;
+
+ spin_lock(&efivars->lock);
+ status = efivars->ops->get_variable(var->var.VariableName,
+ &var->var.VendorGuid,
+ &attributes, &datasize,
+ (data + 4));
+ spin_unlock(&efivars->lock);
+
+ if (status != EFI_SUCCESS)
+ goto out_free;
+
+ memcpy(data, &attributes, 4);
+ size = simple_read_from_buffer(userbuf, count, ppos,
+ data, datasize + 4);
+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_uid = inode->i_gid = 0;
+ 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;
+}
+
+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;
+
+ /*
+ * We need a GUID, plus at least one letter for the variable name,
+ * plus the '-' separator
+ */
+ if (dentry->d_name.len < GUID_LEN + 2)
+ return -EINVAL;
+
+ inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0);
+ if (!inode)
+ return -ENOSPC;
+
+ 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(&efivars->lock);
+ list_add(&var->list, &efivars->list);
+ spin_unlock(&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(&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(&efivars->lock);
+ efivar_unregister(var);
+ drop_nlink(dir);
+ dput(dentry);
+ return 0;
+ }
+
+ spin_unlock(&efivars->lock);
+ return -EINVAL;
+};
+
+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;
+
+ 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 = PSTOREFS_MAGIC;
+ sb->s_op = &efivarfs_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 = d_alloc_name(root, name);
+ if (!dentry)
+ goto fail_inode;
+
+ /* copied by the above to local storage in the dentry. */
+ kfree(name);
+
+ spin_lock(&efivars->lock);
+ efivars->ops->get_variable(entry->var.VariableName,
+ &entry->var.VendorGuid,
+ &entry->var.Attributes,
+ &size,
+ NULL);
+ spin_unlock(&efivars->lock);
+
+ mutex_lock(&inode->i_mutex);
+ inode->i_private = entry;
+ i_size_write(inode, size+4);
+ mutex_unlock(&inode->i_mutex);
+ d_add(dentry, inode);
+ }
+
+ return 0;
+
+fail_inode:
+ iput(inode);
+fail_name:
+ kfree(name);
+fail:
+ return -ENOMEM;
+}
+
+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,
+};
+
+static const struct inode_operations efivarfs_dir_inode_operations = {
+ .lookup = simple_lookup,
+ .unlink = efivarfs_unlink,
+ .create = efivarfs_create,
+};
+
+static struct pstore_info efi_pstore_info;
+
#ifdef CONFIG_PSTORE
static int efi_pstore_open(struct pstore_info *psi)
efi_char16_t *variable_name,
efi_guid_t *vendor_guid)
{
- int i, short_name_size = variable_name_size / sizeof(efi_char16_t) + 38;
+ int i, short_name_size;
char *short_name;
struct efivar_entry *new_efivar;
- short_name = kzalloc(short_name_size + 1, GFP_KERNEL);
+ /*
+ * 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) {
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);
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.
pstore_register(&efivars->efi_pstore_info);
}
+ register_filesystem(&efivarfs_type);
+
out:
kfree(variable_name);
}
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
projects / linux-beck.git / blobdiff