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;
while (!__ratelimit(&file->f_cred->user->ratelimit)) {
if (!msleep_interruptible(50))
return -EINTR;
}
err = efivar_entry_size(var, &datasize);
/*
* efivarfs represents uncommitted variables with
* zero-length files. Reading them should return EOF.
*/
if (err == -ENOENT)
return 0;
else 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 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;
int err = -ENOMEM;
bool is_removable = false;
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 = ucs2_utf8size(entry->var.VariableName);
/* name, plus '-', plus GUID, plus NUL*/
name = kmalloc(len + 1 + EFI_VARIABLE_GUID_LEN + 1, GFP_KERNEL);
if (!name)
goto fail;
ucs2_as_utf8(name, entry->var.VariableName, len);
if (efivar_variable_is_removable(entry->var.VendorGuid, name, len))
is_removable = true;
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,
is_removable);
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;
}
