blob: 90001da9abfdfe98b01a0eacdb5381425234b126 [file] [log] [blame]
Matt Flemingd68772b2013-02-08 16:27:24 +00001/*
2 * Copyright (C) 2012 Red Hat, Inc.
3 * Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9
10#include <linux/efi.h>
11#include <linux/fs.h>
Linus Torvalds20b4fb42013-05-01 17:51:54 -070012#include <linux/slab.h>
Matt Flemingd68772b2013-02-08 16:27:24 +000013
14#include "internal.h"
15
Matt Flemingd68772b2013-02-08 16:27:24 +000016static ssize_t efivarfs_file_write(struct file *file,
17 const char __user *userbuf, size_t count, loff_t *ppos)
18{
19 struct efivar_entry *var = file->private_data;
20 void *data;
21 u32 attributes;
22 struct inode *inode = file->f_mapping->host;
23 unsigned long datasize = count - sizeof(attributes);
Geyslan G. Bemaca32b52013-10-30 15:57:41 -030024 ssize_t bytes;
Matt Flemingd68772b2013-02-08 16:27:24 +000025 bool set = false;
26
27 if (count < sizeof(attributes))
28 return -EINVAL;
29
30 if (copy_from_user(&attributes, userbuf, sizeof(attributes)))
31 return -EFAULT;
32
33 if (attributes & ~(EFI_VARIABLE_MASK))
34 return -EINVAL;
35
Geyslan G. Bemaca32b52013-10-30 15:57:41 -030036 data = memdup_user(userbuf + sizeof(attributes), datasize);
37 if (IS_ERR(data))
38 return PTR_ERR(data);
Matt Flemingd68772b2013-02-08 16:27:24 +000039
40 bytes = efivar_entry_set_get_size(var, attributes, &datasize,
41 data, &set);
Lingzhu Xiang3fab70c2013-05-10 18:29:21 +080042 if (!set && bytes) {
43 if (bytes == -ENOENT)
44 bytes = -EIO;
Matt Flemingd68772b2013-02-08 16:27:24 +000045 goto out;
Lingzhu Xiang3fab70c2013-05-10 18:29:21 +080046 }
Matt Flemingd68772b2013-02-08 16:27:24 +000047
48 if (bytes == -ENOENT) {
49 drop_nlink(inode);
Al Virob5830432014-10-31 01:22:04 -040050 d_delete(file->f_path.dentry);
51 dput(file->f_path.dentry);
Matt Flemingd68772b2013-02-08 16:27:24 +000052 } else {
53 mutex_lock(&inode->i_mutex);
54 i_size_write(inode, datasize + sizeof(attributes));
55 mutex_unlock(&inode->i_mutex);
56 }
57
58 bytes = count;
59
60out:
61 kfree(data);
62
63 return bytes;
64}
65
66static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
67 size_t count, loff_t *ppos)
68{
69 struct efivar_entry *var = file->private_data;
70 unsigned long datasize = 0;
71 u32 attributes;
72 void *data;
73 ssize_t size = 0;
74 int err;
75
76 err = efivar_entry_size(var, &datasize);
Lingzhu Xiang3fab70c2013-05-10 18:29:21 +080077
78 /*
79 * efivarfs represents uncommitted variables with
80 * zero-length files. Reading them should return EOF.
81 */
82 if (err == -ENOENT)
83 return 0;
84 else if (err)
Matt Flemingd68772b2013-02-08 16:27:24 +000085 return err;
86
87 data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL);
88
89 if (!data)
90 return -ENOMEM;
91
92 size = efivar_entry_get(var, &attributes, &datasize,
93 data + sizeof(attributes));
94 if (size)
95 goto out_free;
96
97 memcpy(data, &attributes, sizeof(attributes));
98 size = simple_read_from_buffer(userbuf, count, ppos,
99 data, datasize + sizeof(attributes));
100out_free:
101 kfree(data);
102
103 return size;
104}
105
106const struct file_operations efivarfs_file_operations = {
H. Peter Anvinf53f2922013-04-20 09:16:44 -0700107 .open = simple_open,
Matt Flemingd68772b2013-02-08 16:27:24 +0000108 .read = efivarfs_file_read,
109 .write = efivarfs_file_write,
110 .llseek = no_llseek,
111};