Commit | Line | Data |
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d68772b7 MF |
1 | /* |
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> | |
20b4fb48 | 12 | #include <linux/slab.h> |
d68772b7 MF |
13 | |
14 | #include "internal.h" | |
15 | ||
d68772b7 MF |
16 | static 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); | |
24 | ssize_t bytes = 0; | |
25 | 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 | ||
36 | data = kmalloc(datasize, GFP_KERNEL); | |
37 | if (!data) | |
38 | return -ENOMEM; | |
39 | ||
40 | if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) { | |
41 | bytes = -EFAULT; | |
42 | goto out; | |
43 | } | |
44 | ||
45 | bytes = efivar_entry_set_get_size(var, attributes, &datasize, | |
46 | data, &set); | |
3fab70c1 LX |
47 | if (!set && bytes) { |
48 | if (bytes == -ENOENT) | |
49 | bytes = -EIO; | |
d68772b7 | 50 | goto out; |
3fab70c1 | 51 | } |
d68772b7 MF |
52 | |
53 | if (bytes == -ENOENT) { | |
54 | drop_nlink(inode); | |
55 | d_delete(file->f_dentry); | |
56 | dput(file->f_dentry); | |
57 | } else { | |
58 | mutex_lock(&inode->i_mutex); | |
59 | i_size_write(inode, datasize + sizeof(attributes)); | |
60 | mutex_unlock(&inode->i_mutex); | |
61 | } | |
62 | ||
63 | bytes = count; | |
64 | ||
65 | out: | |
66 | kfree(data); | |
67 | ||
68 | return bytes; | |
69 | } | |
70 | ||
71 | static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, | |
72 | size_t count, loff_t *ppos) | |
73 | { | |
74 | struct efivar_entry *var = file->private_data; | |
75 | unsigned long datasize = 0; | |
76 | u32 attributes; | |
77 | void *data; | |
78 | ssize_t size = 0; | |
79 | int err; | |
80 | ||
81 | err = efivar_entry_size(var, &datasize); | |
3fab70c1 LX |
82 | |
83 | /* | |
84 | * efivarfs represents uncommitted variables with | |
85 | * zero-length files. Reading them should return EOF. | |
86 | */ | |
87 | if (err == -ENOENT) | |
88 | return 0; | |
89 | else if (err) | |
d68772b7 MF |
90 | return err; |
91 | ||
92 | data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL); | |
93 | ||
94 | if (!data) | |
95 | return -ENOMEM; | |
96 | ||
97 | size = efivar_entry_get(var, &attributes, &datasize, | |
98 | data + sizeof(attributes)); | |
99 | if (size) | |
100 | goto out_free; | |
101 | ||
102 | memcpy(data, &attributes, sizeof(attributes)); | |
103 | size = simple_read_from_buffer(userbuf, count, ppos, | |
104 | data, datasize + sizeof(attributes)); | |
105 | out_free: | |
106 | kfree(data); | |
107 | ||
108 | return size; | |
109 | } | |
110 | ||
111 | const struct file_operations efivarfs_file_operations = { | |
f53f292e | 112 | .open = simple_open, |
d68772b7 MF |
113 | .read = efivarfs_file_read, |
114 | .write = efivarfs_file_write, | |
115 | .llseek = no_llseek, | |
116 | }; |