| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <1366148520-29954-6-git-send-email-matt@console-pimps.org>
Date: Tue, 16 Apr 2013 22:41:59 +0100
From: Matt Fleming <matt@...sole-pimps.org>
To: linux-efi@...r.kernel.org
Cc: linux-kernel@...r.kernel.org, "H. Peter Anvin" <hpa@...or.com>,
Matt Fleming <matt.fleming@...el.com>,
Matthew Garrett <matthew.garrett@...ula.com>,
Jeremy Kerr <jk@...abs.org>, Tom Gundersen <teg@...m.no>
Subject: [PATCH 5/6] efivarfs: Move to fs/efivarfs
From: Matt Fleming <matt.fleming@...el.com>
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@...ula.com>
Cc: Jeremy Kerr <jk@...abs.org>
Cc: Tom Gundersen <teg@...m.no>
Signed-off-by: Matt Fleming <matt.fleming@...el.com>
---
MAINTAINERS | 9 +
drivers/firmware/efivars.c | 495 --------------------------------------------
fs/Kconfig | 1 +
fs/Makefile | 1 +
fs/efivarfs/Kconfig | 12 ++
fs/efivarfs/Makefile | 7 +
fs/efivarfs/file.c | 111 ++++++++++
fs/efivarfs/inode.c | 173 ++++++++++++++++
fs/efivarfs/internal.h | 22 ++
fs/efivarfs/super.c | 266 ++++++++++++++++++++++++
10 files changed, 602 insertions(+), 495 deletions(-)
create mode 100644 fs/efivarfs/Kconfig
create mode 100644 fs/efivarfs/Makefile
create mode 100644 fs/efivarfs/file.c
create mode 100644 fs/efivarfs/inode.c
create mode 100644 fs/efivarfs/internal.h
create mode 100644 fs/efivarfs/super.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 9e4862b..0855f44 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -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@...ula.com>
+M: Jeremy Kerr <jk@...abs.org>
+M: Matt Fleming <matt.fleming@...el.com>
+T: git git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi.git
+L: linux-efi@...r.kernel.org
+S: Maintained
+F: fs/efivarfs/
+
EFIFB FRAMEBUFFER DRIVER
L: linux-fbdev@...r.kernel.org
M: Peter Jones <pjones@...hat.com>
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index 2ddd2cc..671872e 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -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;
@@ -597,492 +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, &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)
@@ -2158,8 +1665,6 @@ int efivars_register(struct efivars *efivars,
__efivars = efivars;
- register_filesystem(&efivarfs_type);
-
return 0;
}
EXPORT_SYMBOL_GPL(efivars_register);
diff --git a/fs/Kconfig b/fs/Kconfig
index 780725a..c229f82 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -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
diff --git a/fs/Makefile b/fs/Makefile
index 9d53192..0fde6a3 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -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/
diff --git a/fs/efivarfs/Kconfig b/fs/efivarfs/Kconfig
new file mode 100644
index 0000000..1fb2b7f
--- /dev/null
+++ b/fs/efivarfs/Kconfig
@@ -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.
diff --git a/fs/efivarfs/Makefile b/fs/efivarfs/Makefile
new file mode 100644
index 0000000..955d478
--- /dev/null
+++ b/fs/efivarfs/Makefile
@@ -0,0 +1,7 @@
+#
+# Makefile for the efivarfs filesystem
+#
+
+obj-$(CONFIG_EFIVAR_FS) += efivarfs.o
+
+efivarfs-objs := inode.o file.o super.o
diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c
new file mode 100644
index 0000000..aeb0368
--- /dev/null
+++ b/fs/efivarfs/file.c
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2012 Red Hat, Inc.
+ * Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@...onical.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,
+};
diff --git a/fs/efivarfs/inode.c b/fs/efivarfs/inode.c
new file mode 100644
index 0000000..640e289
--- /dev/null
+++ b/fs/efivarfs/inode.c
@@ -0,0 +1,173 @@
+/*
+ * Copyright (C) 2012 Red Hat, Inc.
+ * Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@...onical.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,
+};
diff --git a/fs/efivarfs/internal.h b/fs/efivarfs/internal.h
new file mode 100644
index 0000000..b5ff16a
--- /dev/null
+++ b/fs/efivarfs/internal.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2012 Red Hat, Inc.
+ * Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@...onical.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 */
diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c
new file mode 100644
index 0000000..bfbd425
--- /dev/null
+++ b/fs/efivarfs/super.c
@@ -0,0 +1,266 @@
+/*
+ * Copyright (C) 2012 Red Hat, Inc.
+ * Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@...onical.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, &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);
--
1.7.10.4
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists