2 * Copyright (C) 2010 IBM Corporation
5 * Mimi Zohar <zohar@us.ibm.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, version 2 of the License.
12 * - Used to signal when key is on keyring
13 * - Get the key and enable EVM
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 #include <linux/uaccess.h>
19 #include <linux/module.h>
22 static struct dentry *evm_init_tpm;
25 * evm_read_key - read() for <securityfs>/evm
27 * @filp: file pointer, not actually used
28 * @buf: where to put the result
29 * @count: maximum to send along
30 * @ppos: where to start
32 * Returns number of bytes read or error code, as appropriate
34 static ssize_t evm_read_key(struct file *filp, char __user *buf,
35 size_t count, loff_t *ppos)
43 sprintf(temp, "%d", evm_initialized);
44 rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
50 * evm_write_key - write() for <securityfs>/evm
51 * @file: file pointer, not actually used
52 * @buf: where to get the data from
54 * @ppos: where to start
56 * Used to signal that key is on the kernel key ring.
57 * - get the integrity hmac key from the kernel key ring
58 * - create list of hmac protected extended attributes
59 * Returns number of bytes written or error code, as appropriate
61 static ssize_t evm_write_key(struct file *file, const char __user *buf,
62 size_t count, loff_t *ppos)
67 if (!capable(CAP_SYS_ADMIN) || (evm_initialized & EVM_INIT_HMAC))
70 if (count >= sizeof(temp) || count == 0)
73 if (copy_from_user(temp, buf, count) != 0)
78 if ((sscanf(temp, "%d", &i) != 1) || (i != 1))
86 static const struct file_operations evm_key_ops = {
88 .write = evm_write_key,
91 int __init evm_init_secfs(void)
95 evm_init_tpm = securityfs_create_file("evm", S_IRUSR | S_IRGRP,
96 NULL, NULL, &evm_key_ops);
97 if (!evm_init_tpm || IS_ERR(evm_init_tpm))