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efivarfs: Move to fs/efivarfs 

Now that efivarfs uses the efivar API, move it out of efivars.c and
into fs/efivarfs where it belongs. This move will eventually allow us
to enable the efivarfs code without having to also enable
CONFIG_EFI_VARS built, and vice versa.

Furthermore, things like,

    mount -t efivarfs none /sys/firmware/efi/efivars

will now work if efivarfs is built as a module without requiring the
use of MODULE_ALIAS(), which would have been necessary when the
efivarfs code was part of efivars.c.

Cc: Matthew Garrett <matthew.garrett@nebula.com>
Cc: Jeremy Kerr <jk@ozlabs.org>
Reviewed-by: Tom Gundersen <teg@jklm.no>
Tested-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
This commit is contained in:
Matt Fleming 2013-02-08 16:27:24 +00:00
parent 048517722c
commit d68772b7c8
10 changed files with 603 additions and 496 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
MAINTAINERS
View File

@ -2990,6 +2990,15 @@ F: arch/x86/platform/efi/*
F: drivers/firmware/efivars.c
F: include/linux/efi*.h
EFI VARIABLE FILESYSTEM
M: Matthew Garrett <matthew.garrett@nebula.com>
M: Jeremy Kerr <jk@ozlabs.org>
M: Matt Fleming <matt.fleming@intel.com>
T: git git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi.git
L: linux-efi@vger.kernel.org
S: Maintained
F: fs/efivarfs/
EFIFB FRAMEBUFFER DRIVER
L: linux-fbdev@vger.kernel.org
M: Peter Jones <pjones@redhat.com>

496
drivers/firmware/efivars.c
View File

@ -94,7 +94,6 @@ MODULE_DESCRIPTION("sysfs interface to EFI Variables");
MODULE_LICENSE("GPL");
MODULE_VERSION(EFIVARS_VERSION);
static LIST_HEAD(efivarfs_list);
LIST_HEAD(efivar_sysfs_list);
EXPORT_SYMBOL_GPL(efivar_sysfs_list);
@ -558,12 +557,6 @@ static struct kobj_type efivar_ktype = {
.default_attrs = def_attrs,
};
static int efivarfs_file_open(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return 0;
}
static int efi_status_to_err(efi_status_t status)
{
int err;
@ -597,493 +590,6 @@ static int efi_status_to_err(efi_status_t status)
return err;
}
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;
void *data;
u32 attributes;
struct inode *inode = file->f_mapping->host;
unsigned long datasize = count - sizeof(attributes);
ssize_t bytes = 0;
bool set = false;
if (count < sizeof(attributes))
return -EINVAL;
if (copy_from_user(&attributes, userbuf, sizeof(attributes)))
return -EFAULT;
if (attributes & ~(EFI_VARIABLE_MASK))
return -EINVAL;
data = kmalloc(datasize, GFP_KERNEL);
if (!data)
return -ENOMEM;
if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) {
bytes = -EFAULT;
goto out;
}
bytes = efivar_entry_set_get_size(var, attributes, &datasize,
data, &set);
if (!set && bytes)
goto out;
if (!bytes) {
mutex_lock(&inode->i_mutex);
i_size_write(inode, datasize + sizeof(attributes));
mutex_unlock(&inode->i_mutex);
} else if (bytes == -ENOENT) {
drop_nlink(inode);
d_delete(file->f_dentry);
dput(file->f_dentry);
} else
pr_warn("efivarfs: inconsistent EFI variable implementation? "
"status=%zu\n", bytes);
bytes = count;
out:
kfree(data);
return bytes;
}
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;
unsigned long datasize = 0;
u32 attributes;
void *data;
ssize_t size = 0;
int err;
err = efivar_entry_size(var, &datasize);
if (err)
return err;
data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL);
if (!data)
return -ENOMEM;
size = efivar_entry_get(var, &attributes, &datasize,
data + sizeof(attributes));
if (size)
goto out_free;
memcpy(data, &attributes, sizeof(attributes));
size = simple_read_from_buffer(userbuf, count, ppos,
data, datasize + sizeof(attributes));
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_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;
}
/*
* Return true if 'str' is a valid efivarfs filename of the form,
*
* VariableName-12345678-1234-1234-1234-1234567891bc
*/
static bool efivarfs_valid_name(const char *str, int len)
{
static const char dashes[EFI_VARIABLE_GUID_LEN] = {
[8] = 1, [13] = 1, [18] = 1, [23] = 1
};
const char *s = str + len - EFI_VARIABLE_GUID_LEN;
int i;
/*
* We need a GUID, plus at least one letter for the variable name,
* plus the '-' separator
*/
if (len < EFI_VARIABLE_GUID_LEN + 2)
return false;
/* GUID must be preceded by a '-' */
if (*(s - 1) != '-')
return false;
/*
* Validate that 's' is of the correct format, e.g.
*
* 12345678-1234-1234-1234-123456789abc
*/
for (i = 0; i < EFI_VARIABLE_GUID_LEN; i++) {
if (dashes[i]) {
if (*s++ != '-')
return false;
} else {
if (!isxdigit(*s++))
return false;
}
}
return true;
}
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 efivar_entry *var;
int namelen, i = 0, err = 0;
if (!efivarfs_valid_name(dentry->d_name.name, dentry->d_name.len))
return -EINVAL;
inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0);
if (!inode)
return -ENOMEM;
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 - EFI_VARIABLE_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;
efivar_entry_add(var, &efivarfs_list);
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;
if (efivar_entry_delete(var))
return -EINVAL;
drop_nlink(dentry->d_inode);
dput(dentry);
return 0;
};
/*
* Compare two efivarfs file names.
*
* An efivarfs filename is composed of two parts,
*
* 1. A case-sensitive variable name
* 2. A case-insensitive GUID
*
* So we need to perform a case-sensitive match on part 1 and a
* case-insensitive match on part 2.
*/
static int efivarfs_d_compare(const struct dentry *parent, const struct inode *pinode,
const struct dentry *dentry, const struct inode *inode,
unsigned int len, const char *str,
const struct qstr *name)
{
int guid = len - EFI_VARIABLE_GUID_LEN;
if (name->len != len)
return 1;
/* Case-sensitive compare for the variable name */
if (memcmp(str, name->name, guid))
return 1;
/* Case-insensitive compare for the GUID */
return strncasecmp(name->name + guid, str + guid, EFI_VARIABLE_GUID_LEN);
}
static int efivarfs_d_hash(const struct dentry *dentry,
const struct inode *inode, struct qstr *qstr)
{
unsigned long hash = init_name_hash();
const unsigned char *s = qstr->name;
unsigned int len = qstr->len;
if (!efivarfs_valid_name(s, len))
return -EINVAL;
while (len-- > EFI_VARIABLE_GUID_LEN)
hash = partial_name_hash(*s++, hash);
/* GUID is case-insensitive. */
while (len--)
hash = partial_name_hash(tolower(*s++), hash);
qstr->hash = end_name_hash(hash);
return 0;
}
/*
* Retaining negative dentries for an in-memory filesystem just wastes
* memory and lookup time: arrange for them to be deleted immediately.
*/
static int efivarfs_delete_dentry(const struct dentry *dentry)
{
return 1;
}
static struct dentry_operations efivarfs_d_ops = {
.d_compare = efivarfs_d_compare,
.d_hash = efivarfs_d_hash,
.d_delete = efivarfs_delete_dentry,
};
static struct dentry *efivarfs_alloc_dentry(struct dentry *parent, char *name)
{
struct dentry *d;
struct qstr q;
int err;
q.name = name;
q.len = strlen(name);
err = efivarfs_d_hash(NULL, NULL, &q);
if (err)
return ERR_PTR(err);
d = d_alloc(parent, &q);
if (d)
return d;
return ERR_PTR(-ENOMEM);
}
static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor,
unsigned long name_size, void *data)
{
struct super_block *sb = (struct super_block *)data;
struct efivar_entry *entry;
struct inode *inode = NULL;
struct dentry *dentry, *root = sb->s_root;
unsigned long size = 0;
char *name;
int len, i;
int err = -ENOMEM;
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
if (!entry)
return err;
memcpy(entry->var.VariableName, name16, name_size);
memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));
len = utf16_strlen(entry->var.VariableName);
/* name, plus '-', plus GUID, plus NUL*/
name = kmalloc(len + 1 + EFI_VARIABLE_GUID_LEN + 1, GFP_KERNEL);
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 + EFI_VARIABLE_GUID_LEN+1] = '\0';
inode = efivarfs_get_inode(sb, root->d_inode, S_IFREG | 0644, 0);
if (!inode)
goto fail_name;
dentry = efivarfs_alloc_dentry(root, name);
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto fail_inode;
}
/* copied by the above to local storage in the dentry. */
kfree(name);
efivar_entry_size(entry, &size);
efivar_entry_add(entry, &efivarfs_list);
mutex_lock(&inode->i_mutex);
inode->i_private = entry;
i_size_write(inode, size + sizeof(entry->var.Attributes));
mutex_unlock(&inode->i_mutex);
d_add(dentry, inode);
return 0;
fail_inode:
iput(inode);
fail_name:
kfree(name);
fail:
kfree(entry);
return err;
}
static int efivarfs_destroy(struct efivar_entry *entry, void *data)
{
efivar_entry_remove(entry);
kfree(entry);
return 0;
}
static int efivarfs_fill_super(struct super_block *sb, void *data, int silent)
{
struct inode *inode = NULL;
struct dentry *root;
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 = EFIVARFS_MAGIC;
sb->s_op = &efivarfs_ops;
sb->s_d_op = &efivarfs_d_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;
INIT_LIST_HEAD(&efivarfs_list);
err = efivar_init(efivarfs_callback, (void *)sb, false,
true, &efivarfs_list);
if (err)
__efivar_entry_iter(efivarfs_destroy, &efivarfs_list, NULL, NULL);
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;
/* Remove all entries and destroy */
__efivar_entry_iter(efivarfs_destroy, &efivarfs_list, NULL, NULL);
}
static struct file_system_type efivarfs_type = {
.name = "efivarfs",
.mount = efivarfs_mount,
.kill_sb = efivarfs_kill_sb,
};
MODULE_ALIAS_FS("efivarfs");
/*
* Handle negative dentry.
*/
static struct dentry *efivarfs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
if (dentry->d_name.len > NAME_MAX)
return ERR_PTR(-ENAMETOOLONG);
d_add(dentry, NULL);
return NULL;
}
static const struct inode_operations efivarfs_dir_inode_operations = {
.lookup = efivarfs_lookup,
.unlink = efivarfs_unlink,
.create = efivarfs_create,
};
static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t pos, size_t count)
@ -2164,8 +1670,6 @@ int efivars_register(struct efivars *efivars,
__efivars = efivars;
register_filesystem(&efivarfs_type);
return 0;
}
EXPORT_SYMBOL_GPL(efivars_register);

1
fs/Kconfig
View File

@ -211,6 +211,7 @@ source "fs/sysv/Kconfig"
source "fs/ufs/Kconfig"
source "fs/exofs/Kconfig"
source "fs/f2fs/Kconfig"
source "fs/efivarfs/Kconfig"
endif # MISC_FILESYSTEMS

1
fs/Makefile
View File

@ -127,3 +127,4 @@ obj-$(CONFIG_F2FS_FS) += f2fs/
obj-y += exofs/ # Multiple modules
obj-$(CONFIG_CEPH_FS) += ceph/
obj-$(CONFIG_PSTORE) += pstore/
obj-$(CONFIG_EFIVAR_FS) += efivarfs/

12
fs/efivarfs/Kconfig Normal file
View File

@ -0,0 +1,12 @@
config EFIVAR_FS
tristate "EFI Variable filesystem"
depends on EFI_VARS
help
efivarfs is a replacement filesystem for the old EFI
variable support via sysfs, as it doesn't suffer from the
same 1024-byte variable size limit.
To compile this file system support as a module, choose M
here. The module will be called efivarfs.
If unsure, say N.

7
fs/efivarfs/Makefile Normal file
View File

@ -0,0 +1,7 @@
#
# Makefile for the efivarfs filesystem
#
obj-$(CONFIG_EFIVAR_FS) += efivarfs.o
efivarfs-objs := inode.o file.o super.o

111
fs/efivarfs/file.c Normal file
View File

@ -0,0 +1,111 @@
/*
* Copyright (C) 2012 Red Hat, Inc.
* Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/efi.h>
#include <linux/fs.h>
#include "internal.h"
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;
void *data;
u32 attributes;
struct inode *inode = file->f_mapping->host;
unsigned long datasize = count - sizeof(attributes);
ssize_t bytes = 0;
bool set = false;
if (count < sizeof(attributes))
return -EINVAL;
if (copy_from_user(&attributes, userbuf, sizeof(attributes)))
return -EFAULT;
if (attributes & ~(EFI_VARIABLE_MASK))
return -EINVAL;
data = kmalloc(datasize, GFP_KERNEL);
if (!data)
return -ENOMEM;
if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) {
bytes = -EFAULT;
goto out;
}
bytes = efivar_entry_set_get_size(var, attributes, &datasize,
data, &set);
if (!set && bytes)
goto out;
if (bytes == -ENOENT) {
drop_nlink(inode);
d_delete(file->f_dentry);
dput(file->f_dentry);
} else {
mutex_lock(&inode->i_mutex);
i_size_write(inode, datasize + sizeof(attributes));
mutex_unlock(&inode->i_mutex);
}
bytes = count;
out:
kfree(data);
return bytes;
}
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;
unsigned long datasize = 0;
u32 attributes;
void *data;
ssize_t size = 0;
int err;
err = efivar_entry_size(var, &datasize);
if (err)
return err;
data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL);
if (!data)
return -ENOMEM;
size = efivar_entry_get(var, &attributes, &datasize,
data + sizeof(attributes));
if (size)
goto out_free;
memcpy(data, &attributes, sizeof(attributes));
size = simple_read_from_buffer(userbuf, count, ppos,
data, datasize + sizeof(attributes));
out_free:
kfree(data);
return size;
}
const struct file_operations efivarfs_file_operations = {
.open = efivarfs_file_open,
.read = efivarfs_file_read,
.write = efivarfs_file_write,
.llseek = no_llseek,
};

173
fs/efivarfs/inode.c Normal file
View File

@ -0,0 +1,173 @@
/*
* Copyright (C) 2012 Red Hat, Inc.
* Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/efi.h>
#include <linux/fs.h>
#include <linux/ctype.h>
#include "internal.h"
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_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;
}
/*
* Return true if 'str' is a valid efivarfs filename of the form,
*
* VariableName-12345678-1234-1234-1234-1234567891bc
*/
bool efivarfs_valid_name(const char *str, int len)
{
static const char dashes[EFI_VARIABLE_GUID_LEN] = {
[8] = 1, [13] = 1, [18] = 1, [23] = 1
};
const char *s = str + len - EFI_VARIABLE_GUID_LEN;
int i;
/*
* We need a GUID, plus at least one letter for the variable name,
* plus the '-' separator
*/
if (len < EFI_VARIABLE_GUID_LEN + 2)
return false;
/* GUID must be preceded by a '-' */
if (*(s - 1) != '-')
return false;
/*
* Validate that 's' is of the correct format, e.g.
*
* 12345678-1234-1234-1234-123456789abc
*/
for (i = 0; i < EFI_VARIABLE_GUID_LEN; i++) {
if (dashes[i]) {
if (*s++ != '-')
return false;
} else {
if (!isxdigit(*s++))
return false;
}
}
return true;
}
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 efivar_entry *var;
int namelen, i = 0, err = 0;
if (!efivarfs_valid_name(dentry->d_name.name, dentry->d_name.len))
return -EINVAL;
inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0);
if (!inode)
return -ENOMEM;
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 - EFI_VARIABLE_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;
efivar_entry_add(var, &efivarfs_list);
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;
if (efivar_entry_delete(var))
return -EINVAL;
drop_nlink(dentry->d_inode);
dput(dentry);
return 0;
};
/*
* Handle negative dentry.
*/
static struct dentry *efivarfs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
if (dentry->d_name.len > NAME_MAX)
return ERR_PTR(-ENAMETOOLONG);
d_add(dentry, NULL);
return NULL;
}
const struct inode_operations efivarfs_dir_inode_operations = {
.lookup = efivarfs_lookup,
.unlink = efivarfs_unlink,
.create = efivarfs_create,
};

22
fs/efivarfs/internal.h Normal file
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@ -0,0 +1,22 @@
/*
* Copyright (C) 2012 Red Hat, Inc.
* Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef EFIVAR_FS_INTERNAL_H
#define EFIVAR_FS_INTERNAL_H
#include <linux/list.h>
extern const struct file_operations efivarfs_file_operations;
extern const struct inode_operations efivarfs_dir_inode_operations;
extern bool efivarfs_valid_name(const char *str, int len);
extern struct inode *efivarfs_get_inode(struct super_block *sb,
const struct inode *dir, int mode, dev_t dev);
extern struct list_head efivarfs_list;
#endif /* EFIVAR_FS_INTERNAL_H */

267
fs/efivarfs/super.c Normal file
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@ -0,0 +1,267 @@
/*
* Copyright (C) 2012 Red Hat, Inc.
* Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/ctype.h>
#include <linux/efi.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include "internal.h"
LIST_HEAD(efivarfs_list);
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;
/*
* Compare two efivarfs file names.
*
* An efivarfs filename is composed of two parts,
*
* 1. A case-sensitive variable name
* 2. A case-insensitive GUID
*
* So we need to perform a case-sensitive match on part 1 and a
* case-insensitive match on part 2.
*/
static int efivarfs_d_compare(const struct dentry *parent, const struct inode *pinode,
const struct dentry *dentry, const struct inode *inode,
unsigned int len, const char *str,
const struct qstr *name)
{
int guid = len - EFI_VARIABLE_GUID_LEN;
if (name->len != len)
return 1;
/* Case-sensitive compare for the variable name */
if (memcmp(str, name->name, guid))
return 1;
/* Case-insensitive compare for the GUID */
return strncasecmp(name->name + guid, str + guid, EFI_VARIABLE_GUID_LEN);
}
static int efivarfs_d_hash(const struct dentry *dentry,
const struct inode *inode, struct qstr *qstr)
{
unsigned long hash = init_name_hash();
const unsigned char *s = qstr->name;
unsigned int len = qstr->len;
if (!efivarfs_valid_name(s, len))
return -EINVAL;
while (len-- > EFI_VARIABLE_GUID_LEN)
hash = partial_name_hash(*s++, hash);
/* GUID is case-insensitive. */
while (len--)
hash = partial_name_hash(tolower(*s++), hash);
qstr->hash = end_name_hash(hash);
return 0;
}
/*
* Retaining negative dentries for an in-memory filesystem just wastes
* memory and lookup time: arrange for them to be deleted immediately.
*/
static int efivarfs_delete_dentry(const struct dentry *dentry)
{
return 1;
}
static struct dentry_operations efivarfs_d_ops = {
.d_compare = efivarfs_d_compare,
.d_hash = efivarfs_d_hash,
.d_delete = efivarfs_delete_dentry,
};
static struct dentry *efivarfs_alloc_dentry(struct dentry *parent, char *name)
{
struct dentry *d;
struct qstr q;
int err;
q.name = name;
q.len = strlen(name);
err = efivarfs_d_hash(NULL, NULL, &q);
if (err)
return ERR_PTR(err);
d = d_alloc(parent, &q);
if (d)
return d;
return ERR_PTR(-ENOMEM);
}
static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor,
unsigned long name_size, void *data)
{
struct super_block *sb = (struct super_block *)data;
struct efivar_entry *entry;
struct inode *inode = NULL;
struct dentry *dentry, *root = sb->s_root;
unsigned long size = 0;
char *name;
int len, i;
int err = -ENOMEM;
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
if (!entry)
return err;
memcpy(entry->var.VariableName, name16, name_size);
memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));
len = utf16_strlen(entry->var.VariableName);
/* name, plus '-', plus GUID, plus NUL*/
name = kmalloc(len + 1 + EFI_VARIABLE_GUID_LEN + 1, GFP_KERNEL);
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 + EFI_VARIABLE_GUID_LEN+1] = '\0';
inode = efivarfs_get_inode(sb, root->d_inode, S_IFREG | 0644, 0);
if (!inode)
goto fail_name;
dentry = efivarfs_alloc_dentry(root, name);
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto fail_inode;
}
/* copied by the above to local storage in the dentry. */
kfree(name);
efivar_entry_size(entry, &size);
efivar_entry_add(entry, &efivarfs_list);
mutex_lock(&inode->i_mutex);
inode->i_private = entry;
i_size_write(inode, size + sizeof(entry->var.Attributes));
mutex_unlock(&inode->i_mutex);
d_add(dentry, inode);
return 0;
fail_inode:
iput(inode);
fail_name:
kfree(name);
fail:
kfree(entry);
return err;
}
static int efivarfs_destroy(struct efivar_entry *entry, void *data)
{
efivar_entry_remove(entry);
kfree(entry);
return 0;
}
static int efivarfs_fill_super(struct super_block *sb, void *data, int silent)
{
struct inode *inode = NULL;
struct dentry *root;
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 = EFIVARFS_MAGIC;
sb->s_op = &efivarfs_ops;
sb->s_d_op = &efivarfs_d_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;
INIT_LIST_HEAD(&efivarfs_list);
err = efivar_init(efivarfs_callback, (void *)sb, false,
true, &efivarfs_list);
if (err)
__efivar_entry_iter(efivarfs_destroy, &efivarfs_list, NULL, NULL);
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;
/* Remove all entries and destroy */
__efivar_entry_iter(efivarfs_destroy, &efivarfs_list, NULL, NULL);
}
static struct file_system_type efivarfs_type = {
.name = "efivarfs",
.mount = efivarfs_mount,
.kill_sb = efivarfs_kill_sb,
};
static __init int efivarfs_init(void)
{
if (!efi_enabled(EFI_RUNTIME_SERVICES))
return 0;
if (!efivars_kobject())
return 0;
return register_filesystem(&efivarfs_type);
}
MODULE_AUTHOR("Matthew Garrett, Jeremy Kerr");
MODULE_DESCRIPTION("EFI Variable Filesystem");
MODULE_LICENSE("GPL");
MODULE_ALIAS_FS("efivarfs");
module_init(efivarfs_init);