mirror of
https://github.com/team-infusion-developers/android_kernel_samsung_msm8976.git
synced 2024-10-31 18:09:19 +00:00
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:
parent
048517722c
commit
d68772b7c8
10 changed files with 603 additions and 496 deletions
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@ -2990,6 +2990,15 @@ F: arch/x86/platform/efi/*
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F: drivers/firmware/efivars.c
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F: include/linux/efi*.h
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EFI VARIABLE FILESYSTEM
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M: Matthew Garrett <matthew.garrett@nebula.com>
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M: Jeremy Kerr <jk@ozlabs.org>
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M: Matt Fleming <matt.fleming@intel.com>
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T: git git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi.git
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L: linux-efi@vger.kernel.org
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S: Maintained
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F: fs/efivarfs/
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EFIFB FRAMEBUFFER DRIVER
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L: linux-fbdev@vger.kernel.org
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M: Peter Jones <pjones@redhat.com>
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@ -94,7 +94,6 @@ MODULE_DESCRIPTION("sysfs interface to EFI Variables");
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MODULE_LICENSE("GPL");
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MODULE_VERSION(EFIVARS_VERSION);
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static LIST_HEAD(efivarfs_list);
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LIST_HEAD(efivar_sysfs_list);
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EXPORT_SYMBOL_GPL(efivar_sysfs_list);
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@ -558,12 +557,6 @@ static struct kobj_type efivar_ktype = {
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.default_attrs = def_attrs,
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};
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static int efivarfs_file_open(struct inode *inode, struct file *file)
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{
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file->private_data = inode->i_private;
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return 0;
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}
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static int efi_status_to_err(efi_status_t status)
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{
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int err;
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@ -597,493 +590,6 @@ static int efi_status_to_err(efi_status_t status)
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return err;
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}
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static ssize_t efivarfs_file_write(struct file *file,
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const char __user *userbuf, size_t count, loff_t *ppos)
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{
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struct efivar_entry *var = file->private_data;
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void *data;
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u32 attributes;
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struct inode *inode = file->f_mapping->host;
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unsigned long datasize = count - sizeof(attributes);
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ssize_t bytes = 0;
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bool set = false;
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if (count < sizeof(attributes))
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return -EINVAL;
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if (copy_from_user(&attributes, userbuf, sizeof(attributes)))
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return -EFAULT;
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if (attributes & ~(EFI_VARIABLE_MASK))
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return -EINVAL;
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data = kmalloc(datasize, GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) {
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bytes = -EFAULT;
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goto out;
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}
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bytes = efivar_entry_set_get_size(var, attributes, &datasize,
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data, &set);
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if (!set && bytes)
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goto out;
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if (!bytes) {
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mutex_lock(&inode->i_mutex);
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i_size_write(inode, datasize + sizeof(attributes));
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mutex_unlock(&inode->i_mutex);
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} else if (bytes == -ENOENT) {
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drop_nlink(inode);
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d_delete(file->f_dentry);
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dput(file->f_dentry);
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} else
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pr_warn("efivarfs: inconsistent EFI variable implementation? "
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"status=%zu\n", bytes);
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bytes = count;
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out:
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kfree(data);
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return bytes;
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}
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static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
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size_t count, loff_t *ppos)
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{
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struct efivar_entry *var = file->private_data;
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unsigned long datasize = 0;
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u32 attributes;
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void *data;
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ssize_t size = 0;
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int err;
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err = efivar_entry_size(var, &datasize);
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if (err)
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return err;
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data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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size = efivar_entry_get(var, &attributes, &datasize,
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data + sizeof(attributes));
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if (size)
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goto out_free;
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memcpy(data, &attributes, sizeof(attributes));
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size = simple_read_from_buffer(userbuf, count, ppos,
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data, datasize + sizeof(attributes));
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out_free:
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kfree(data);
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return size;
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}
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static void efivarfs_evict_inode(struct inode *inode)
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{
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clear_inode(inode);
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}
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static const struct super_operations efivarfs_ops = {
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.statfs = simple_statfs,
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.drop_inode = generic_delete_inode,
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.evict_inode = efivarfs_evict_inode,
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.show_options = generic_show_options,
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};
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static struct super_block *efivarfs_sb;
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static const struct inode_operations efivarfs_dir_inode_operations;
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static const struct file_operations efivarfs_file_operations = {
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.open = efivarfs_file_open,
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.read = efivarfs_file_read,
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.write = efivarfs_file_write,
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.llseek = no_llseek,
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};
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static struct inode *efivarfs_get_inode(struct super_block *sb,
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const struct inode *dir, int mode, dev_t dev)
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{
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struct inode *inode = new_inode(sb);
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if (inode) {
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inode->i_ino = get_next_ino();
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inode->i_mode = mode;
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inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
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switch (mode & S_IFMT) {
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case S_IFREG:
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inode->i_fop = &efivarfs_file_operations;
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break;
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case S_IFDIR:
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inode->i_op = &efivarfs_dir_inode_operations;
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inode->i_fop = &simple_dir_operations;
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inc_nlink(inode);
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break;
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}
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}
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return inode;
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}
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/*
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* Return true if 'str' is a valid efivarfs filename of the form,
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*
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* VariableName-12345678-1234-1234-1234-1234567891bc
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*/
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static bool efivarfs_valid_name(const char *str, int len)
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{
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static const char dashes[EFI_VARIABLE_GUID_LEN] = {
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[8] = 1, [13] = 1, [18] = 1, [23] = 1
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};
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const char *s = str + len - EFI_VARIABLE_GUID_LEN;
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int i;
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/*
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* We need a GUID, plus at least one letter for the variable name,
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* plus the '-' separator
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*/
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if (len < EFI_VARIABLE_GUID_LEN + 2)
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return false;
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/* GUID must be preceded by a '-' */
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if (*(s - 1) != '-')
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return false;
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/*
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* Validate that 's' is of the correct format, e.g.
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*
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* 12345678-1234-1234-1234-123456789abc
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*/
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for (i = 0; i < EFI_VARIABLE_GUID_LEN; i++) {
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if (dashes[i]) {
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if (*s++ != '-')
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return false;
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} else {
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if (!isxdigit(*s++))
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return false;
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}
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}
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return true;
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}
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static void efivarfs_hex_to_guid(const char *str, efi_guid_t *guid)
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{
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guid->b[0] = hex_to_bin(str[6]) << 4 | hex_to_bin(str[7]);
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guid->b[1] = hex_to_bin(str[4]) << 4 | hex_to_bin(str[5]);
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guid->b[2] = hex_to_bin(str[2]) << 4 | hex_to_bin(str[3]);
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guid->b[3] = hex_to_bin(str[0]) << 4 | hex_to_bin(str[1]);
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guid->b[4] = hex_to_bin(str[11]) << 4 | hex_to_bin(str[12]);
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guid->b[5] = hex_to_bin(str[9]) << 4 | hex_to_bin(str[10]);
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guid->b[6] = hex_to_bin(str[16]) << 4 | hex_to_bin(str[17]);
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guid->b[7] = hex_to_bin(str[14]) << 4 | hex_to_bin(str[15]);
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guid->b[8] = hex_to_bin(str[19]) << 4 | hex_to_bin(str[20]);
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guid->b[9] = hex_to_bin(str[21]) << 4 | hex_to_bin(str[22]);
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guid->b[10] = hex_to_bin(str[24]) << 4 | hex_to_bin(str[25]);
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guid->b[11] = hex_to_bin(str[26]) << 4 | hex_to_bin(str[27]);
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guid->b[12] = hex_to_bin(str[28]) << 4 | hex_to_bin(str[29]);
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guid->b[13] = hex_to_bin(str[30]) << 4 | hex_to_bin(str[31]);
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guid->b[14] = hex_to_bin(str[32]) << 4 | hex_to_bin(str[33]);
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guid->b[15] = hex_to_bin(str[34]) << 4 | hex_to_bin(str[35]);
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}
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static int efivarfs_create(struct inode *dir, struct dentry *dentry,
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umode_t mode, bool excl)
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{
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struct inode *inode;
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struct efivar_entry *var;
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int namelen, i = 0, err = 0;
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if (!efivarfs_valid_name(dentry->d_name.name, dentry->d_name.len))
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return -EINVAL;
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inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0);
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if (!inode)
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return -ENOMEM;
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var = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
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if (!var) {
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err = -ENOMEM;
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goto out;
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}
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/* length of the variable name itself: remove GUID and separator */
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namelen = dentry->d_name.len - EFI_VARIABLE_GUID_LEN - 1;
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efivarfs_hex_to_guid(dentry->d_name.name + namelen + 1,
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&var->var.VendorGuid);
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for (i = 0; i < namelen; i++)
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var->var.VariableName[i] = dentry->d_name.name[i];
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var->var.VariableName[i] = '\0';
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inode->i_private = var;
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efivar_entry_add(var, &efivarfs_list);
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d_instantiate(dentry, inode);
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dget(dentry);
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out:
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if (err) {
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kfree(var);
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iput(inode);
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}
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return err;
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}
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static int efivarfs_unlink(struct inode *dir, struct dentry *dentry)
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{
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struct efivar_entry *var = dentry->d_inode->i_private;
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if (efivar_entry_delete(var))
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return -EINVAL;
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drop_nlink(dentry->d_inode);
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dput(dentry);
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return 0;
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};
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/*
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* Compare two efivarfs file names.
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*
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* An efivarfs filename is composed of two parts,
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*
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* 1. A case-sensitive variable name
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* 2. A case-insensitive GUID
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*
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* So we need to perform a case-sensitive match on part 1 and a
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* case-insensitive match on part 2.
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*/
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static int efivarfs_d_compare(const struct dentry *parent, const struct inode *pinode,
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const struct dentry *dentry, const struct inode *inode,
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unsigned int len, const char *str,
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const struct qstr *name)
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{
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int guid = len - EFI_VARIABLE_GUID_LEN;
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if (name->len != len)
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return 1;
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/* Case-sensitive compare for the variable name */
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if (memcmp(str, name->name, guid))
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return 1;
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/* Case-insensitive compare for the GUID */
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return strncasecmp(name->name + guid, str + guid, EFI_VARIABLE_GUID_LEN);
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}
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static int efivarfs_d_hash(const struct dentry *dentry,
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const struct inode *inode, struct qstr *qstr)
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{
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unsigned long hash = init_name_hash();
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const unsigned char *s = qstr->name;
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unsigned int len = qstr->len;
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if (!efivarfs_valid_name(s, len))
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return -EINVAL;
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while (len-- > EFI_VARIABLE_GUID_LEN)
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hash = partial_name_hash(*s++, hash);
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/* GUID is case-insensitive. */
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while (len--)
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hash = partial_name_hash(tolower(*s++), hash);
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qstr->hash = end_name_hash(hash);
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return 0;
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}
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/*
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* Retaining negative dentries for an in-memory filesystem just wastes
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* memory and lookup time: arrange for them to be deleted immediately.
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*/
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static int efivarfs_delete_dentry(const struct dentry *dentry)
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{
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return 1;
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}
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static struct dentry_operations efivarfs_d_ops = {
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.d_compare = efivarfs_d_compare,
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.d_hash = efivarfs_d_hash,
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.d_delete = efivarfs_delete_dentry,
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};
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static struct dentry *efivarfs_alloc_dentry(struct dentry *parent, char *name)
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{
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struct dentry *d;
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struct qstr q;
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int err;
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q.name = name;
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q.len = strlen(name);
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err = efivarfs_d_hash(NULL, NULL, &q);
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if (err)
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return ERR_PTR(err);
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d = d_alloc(parent, &q);
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if (d)
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return d;
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return ERR_PTR(-ENOMEM);
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}
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static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor,
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unsigned long name_size, void *data)
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{
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struct super_block *sb = (struct super_block *)data;
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struct efivar_entry *entry;
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struct inode *inode = NULL;
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struct dentry *dentry, *root = sb->s_root;
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unsigned long size = 0;
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char *name;
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int len, i;
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int err = -ENOMEM;
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entry = kmalloc(sizeof(*entry), GFP_KERNEL);
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if (!entry)
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return err;
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memcpy(entry->var.VariableName, name16, name_size);
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memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));
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len = utf16_strlen(entry->var.VariableName);
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/* name, plus '-', plus GUID, plus NUL*/
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name = kmalloc(len + 1 + EFI_VARIABLE_GUID_LEN + 1, GFP_KERNEL);
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if (!name)
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goto fail;
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for (i = 0; i < len; i++)
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name[i] = entry->var.VariableName[i] & 0xFF;
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name[len] = '-';
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efi_guid_unparse(&entry->var.VendorGuid, name + len + 1);
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name[len + EFI_VARIABLE_GUID_LEN+1] = '\0';
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inode = efivarfs_get_inode(sb, root->d_inode, S_IFREG | 0644, 0);
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if (!inode)
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goto fail_name;
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dentry = efivarfs_alloc_dentry(root, name);
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if (IS_ERR(dentry)) {
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err = PTR_ERR(dentry);
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goto fail_inode;
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}
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/* copied by the above to local storage in the dentry. */
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kfree(name);
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efivar_entry_size(entry, &size);
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efivar_entry_add(entry, &efivarfs_list);
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mutex_lock(&inode->i_mutex);
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inode->i_private = entry;
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i_size_write(inode, size + sizeof(entry->var.Attributes));
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mutex_unlock(&inode->i_mutex);
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d_add(dentry, inode);
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|
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return 0;
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fail_inode:
|
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iput(inode);
|
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fail_name:
|
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kfree(name);
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fail:
|
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kfree(entry);
|
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return err;
|
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}
|
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|
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static int efivarfs_destroy(struct efivar_entry *entry, void *data)
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{
|
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efivar_entry_remove(entry);
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kfree(entry);
|
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return 0;
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}
|
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|
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static int efivarfs_fill_super(struct super_block *sb, void *data, int silent)
|
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{
|
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struct inode *inode = NULL;
|
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struct dentry *root;
|
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int err;
|
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|
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efivarfs_sb = sb;
|
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|
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sb->s_maxbytes = MAX_LFS_FILESIZE;
|
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sb->s_blocksize = PAGE_CACHE_SIZE;
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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);
|
||||
|
|
|
@ -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
|
||||
|
||||
|
|
|
@ -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
12
fs/efivarfs/Kconfig
Normal 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
7
fs/efivarfs/Makefile
Normal 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
111
fs/efivarfs/file.c
Normal 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
173
fs/efivarfs/inode.c
Normal 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
22
fs/efivarfs/internal.h
Normal file
|
@ -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
267
fs/efivarfs/super.c
Normal file
|
@ -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);
|
Loading…
Reference in a new issue