blob: 5f22e74bbadea0822e3f6f5378b732ab3c1e333d [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>
Peter Jonesed8b0de2016-02-08 14:48:15 -050013#include <linux/mount.h>
Matt Flemingd68772b2013-02-08 16:27:24 +000014
15#include "internal.h"
16
Matt Flemingd68772b2013-02-08 16:27:24 +000017static ssize_t efivarfs_file_write(struct file *file,
18 const char __user *userbuf, size_t count, loff_t *ppos)
19{
20 struct efivar_entry *var = file->private_data;
21 void *data;
22 u32 attributes;
23 struct inode *inode = file->f_mapping->host;
24 unsigned long datasize = count - sizeof(attributes);
Geyslan G. Bemaca32b52013-10-30 15:57:41 -030025 ssize_t bytes;
Matt Flemingd68772b2013-02-08 16:27:24 +000026 bool set = false;
27
28 if (count < sizeof(attributes))
29 return -EINVAL;
30
31 if (copy_from_user(&attributes, userbuf, sizeof(attributes)))
32 return -EFAULT;
33
34 if (attributes & ~(EFI_VARIABLE_MASK))
35 return -EINVAL;
36
Geyslan G. Bemaca32b52013-10-30 15:57:41 -030037 data = memdup_user(userbuf + sizeof(attributes), datasize);
38 if (IS_ERR(data))
39 return PTR_ERR(data);
Matt Flemingd68772b2013-02-08 16:27:24 +000040
41 bytes = efivar_entry_set_get_size(var, attributes, &datasize,
42 data, &set);
Lingzhu Xiang3fab70c2013-05-10 18:29:21 +080043 if (!set && bytes) {
44 if (bytes == -ENOENT)
45 bytes = -EIO;
Matt Flemingd68772b2013-02-08 16:27:24 +000046 goto out;
Lingzhu Xiang3fab70c2013-05-10 18:29:21 +080047 }
Matt Flemingd68772b2013-02-08 16:27:24 +000048
49 if (bytes == -ENOENT) {
50 drop_nlink(inode);
Al Virob5830432014-10-31 01:22:04 -040051 d_delete(file->f_path.dentry);
52 dput(file->f_path.dentry);
Matt Flemingd68772b2013-02-08 16:27:24 +000053 } else {
Al Viro59551022016-01-22 15:40:57 -050054 inode_lock(inode);
Matt Flemingd68772b2013-02-08 16:27:24 +000055 i_size_write(inode, datasize + sizeof(attributes));
Al Viro59551022016-01-22 15:40:57 -050056 inode_unlock(inode);
Matt Flemingd68772b2013-02-08 16:27:24 +000057 }
58
59 bytes = count;
60
61out:
62 kfree(data);
63
64 return bytes;
65}
66
67static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
68 size_t count, loff_t *ppos)
69{
70 struct efivar_entry *var = file->private_data;
71 unsigned long datasize = 0;
72 u32 attributes;
73 void *data;
74 ssize_t size = 0;
75 int err;
76
77 err = efivar_entry_size(var, &datasize);
Lingzhu Xiang3fab70c2013-05-10 18:29:21 +080078
79 /*
80 * efivarfs represents uncommitted variables with
81 * zero-length files. Reading them should return EOF.
82 */
83 if (err == -ENOENT)
84 return 0;
85 else if (err)
Matt Flemingd68772b2013-02-08 16:27:24 +000086 return err;
87
88 data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL);
89
90 if (!data)
91 return -ENOMEM;
92
93 size = efivar_entry_get(var, &attributes, &datasize,
94 data + sizeof(attributes));
95 if (size)
96 goto out_free;
97
98 memcpy(data, &attributes, sizeof(attributes));
99 size = simple_read_from_buffer(userbuf, count, ppos,
100 data, datasize + sizeof(attributes));
101out_free:
102 kfree(data);
103
104 return size;
105}
106
Peter Jonesed8b0de2016-02-08 14:48:15 -0500107static int
108efivarfs_ioc_getxflags(struct file *file, void __user *arg)
109{
110 struct inode *inode = file->f_mapping->host;
111 unsigned int i_flags;
112 unsigned int flags = 0;
113
114 i_flags = inode->i_flags;
115 if (i_flags & S_IMMUTABLE)
116 flags |= FS_IMMUTABLE_FL;
117
118 if (copy_to_user(arg, &flags, sizeof(flags)))
119 return -EFAULT;
120 return 0;
121}
122
123static int
124efivarfs_ioc_setxflags(struct file *file, void __user *arg)
125{
126 struct inode *inode = file->f_mapping->host;
127 unsigned int flags;
128 unsigned int i_flags = 0;
129 int error;
130
131 if (!inode_owner_or_capable(inode))
132 return -EACCES;
133
134 if (copy_from_user(&flags, arg, sizeof(flags)))
135 return -EFAULT;
136
137 if (flags & ~FS_IMMUTABLE_FL)
138 return -EOPNOTSUPP;
139
140 if (!capable(CAP_LINUX_IMMUTABLE))
141 return -EPERM;
142
143 if (flags & FS_IMMUTABLE_FL)
144 i_flags |= S_IMMUTABLE;
145
146
147 error = mnt_want_write_file(file);
148 if (error)
149 return error;
150
151 inode_lock(inode);
152 inode_set_flags(inode, i_flags, S_IMMUTABLE);
153 inode_unlock(inode);
154
155 mnt_drop_write_file(file);
156
157 return 0;
158}
159
Peter Jones6c5450e2016-05-06 22:39:31 +0100160static long
Peter Jonesed8b0de2016-02-08 14:48:15 -0500161efivarfs_file_ioctl(struct file *file, unsigned int cmd, unsigned long p)
162{
163 void __user *arg = (void __user *)p;
164
165 switch (cmd) {
166 case FS_IOC_GETFLAGS:
167 return efivarfs_ioc_getxflags(file, arg);
168 case FS_IOC_SETFLAGS:
169 return efivarfs_ioc_setxflags(file, arg);
170 }
171
172 return -ENOTTY;
173}
174
Matt Flemingd68772b2013-02-08 16:27:24 +0000175const struct file_operations efivarfs_file_operations = {
H. Peter Anvinf53f2922013-04-20 09:16:44 -0700176 .open = simple_open,
Matt Flemingd68772b2013-02-08 16:27:24 +0000177 .read = efivarfs_file_read,
178 .write = efivarfs_file_write,
179 .llseek = no_llseek,
Peter Jonesed8b0de2016-02-08 14:48:15 -0500180 .unlocked_ioctl = efivarfs_file_ioctl,
Matt Flemingd68772b2013-02-08 16:27:24 +0000181};