diff options
| -rw-r--r-- | drivers/firmware/efivars.c | 384 | ||||
| -rw-r--r-- | include/linux/efi.h | 5 |
2 files changed, 383 insertions, 6 deletions
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index d10c9873dd9a..b605c4849772 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -80,6 +80,10 @@ #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" @@ -91,6 +95,7 @@ MODULE_LICENSE("GPL"); MODULE_VERSION(EFIVARS_VERSION); #define DUMP_NAME_LEN 52 +#define GUID_LEN 37 /* * The maximum size of VariableName + Data = 1024 @@ -108,7 +113,6 @@ struct efi_variable { __u32 Attributes; } __attribute__((packed)); - struct efivar_entry { struct efivars *efivars; struct efi_variable var; @@ -122,6 +126,9 @@ struct efivar_attribute { 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 | \ @@ -629,14 +636,380 @@ static struct kobj_type efivar_ktype = { .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); + + 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; + } + + status = efivars->ops->set_variable(var->var.VariableName, + &var->var.VendorGuid, + attributes, datasize, + data); + + switch (status) { + case EFI_SUCCESS: + mutex_lock(&inode->i_mutex); + i_size_write(inode, count); + mutex_unlock(&inode->i_mutex); + break; + 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; + break; + } +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; + + status = efivars->ops->get_variable(var->var.VariableName, + &var->var.VendorGuid, + &attributes, &datasize, NULL); + + if (status != EFI_BUFFER_TOO_SMALL) + return 0; + + data = kmalloc(datasize + 4, GFP_KERNEL); + + if (!data) + return 0; + + status = efivars->ops->get_variable(var->var.VariableName, + &var->var.VendorGuid, + &attributes, &datasize, + (data + 4)); + + if (status != EFI_SUCCESS) + return 0; + + memcpy(data, &attributes, 4); + size = simple_read_from_buffer(userbuf, count, ppos, + data, datasize + 4); + 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 = efivarfs_get_inode(dir->i_sb, dir, mode, 0); + struct efivars *efivars = &__efivars; + struct efivar_entry *var; + int namelen, i = 0, err = 0; + + if (dentry->d_name.len < 38) + return -EINVAL; + + if (!inode) + return -ENOSPC; + + var = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL); + + if (!var) + return -ENOMEM; + + namelen = dentry->d_name.len - GUID_LEN; + + 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); + 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; + int err; + + 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) { + err = -ENOMEM; + goto fail; + } + inode->i_op = &efivarfs_dir_inode_operations; + + root = d_make_root(inode); + sb->s_root = root; + if (!root) { + err = -ENOMEM; + goto fail; + } + + list_for_each_entry_safe(entry, n, &efivars->list, list) { + struct inode *inode; + struct dentry *dentry, *root = efivarfs_sb->s_root; + char *name; + unsigned long size = 0; + int len, i; + + len = utf16_strlen(entry->var.VariableName); + + /* GUID plus trailing NULL */ + name = kmalloc(len + 38, GFP_ATOMIC); + + 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] = '\0'; + + inode = efivarfs_get_inode(efivarfs_sb, root->d_inode, + S_IFREG | 0644, 0); + dentry = d_alloc_name(root, name); + + efivars->ops->get_variable(entry->var.VariableName, + &entry->var.VendorGuid, + &entry->var.Attributes, + &size, + NULL); + + 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: + iput(inode); + 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, +}; + +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) @@ -1198,6 +1571,8 @@ int register_efivars(struct efivars *efivars, pstore_register(&efivars->efi_pstore_info); } + register_filesystem(&efivarfs_type); + out: kfree(variable_name); @@ -1205,9 +1580,6 @@ out: } 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 diff --git a/include/linux/efi.h b/include/linux/efi.h index 8670eb1eb8cd..b2af1571592b 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -29,7 +29,12 @@ #define EFI_UNSUPPORTED ( 3 | (1UL << (BITS_PER_LONG-1))) #define EFI_BAD_BUFFER_SIZE ( 4 | (1UL << (BITS_PER_LONG-1))) #define EFI_BUFFER_TOO_SMALL ( 5 | (1UL << (BITS_PER_LONG-1))) +#define EFI_NOT_READY ( 6 | (1UL << (BITS_PER_LONG-1))) +#define EFI_DEVICE_ERROR ( 7 | (1UL << (BITS_PER_LONG-1))) +#define EFI_WRITE_PROTECTED ( 8 | (1UL << (BITS_PER_LONG-1))) +#define EFI_OUT_OF_RESOURCES ( 9 | (1UL << (BITS_PER_LONG-1))) #define EFI_NOT_FOUND (14 | (1UL << (BITS_PER_LONG-1))) +#define EFI_SECURITY_VIOLATION (26 | (1UL << (BITS_PER_LONG-1))) typedef unsigned long efi_status_t; typedef u8 efi_bool_t; |