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authorLinus Torvalds <torvalds@linux-foundation.org>2017-05-03 08:50:52 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-05-03 08:50:52 -0700
commit0302e28dee643932ee7b3c112ebccdbb9f8ec32c (patch)
tree405d4cb3f772ef069ed7f291adc4b74a4e73346e /drivers/char/tpm/tpm-dev-common.c
parent89c9fea3c8034cdb2fd745f551cde0b507fd6893 (diff)
parent8979b02aaf1d6de8d52cc143aa4da961ed32e5a2 (diff)
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris: "Highlights: IMA: - provide ">" and "<" operators for fowner/uid/euid rules KEYS: - add a system blacklist keyring - add KEYCTL_RESTRICT_KEYRING, exposes keyring link restriction functionality to userland via keyctl() LSM: - harden LSM API with __ro_after_init - add prlmit security hook, implement for SELinux - revive security_task_alloc hook TPM: - implement contextual TPM command 'spaces'" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (98 commits) tpm: Fix reference count to main device tpm_tis: convert to using locality callbacks tpm: fix handling of the TPM 2.0 event logs tpm_crb: remove a cruft constant keys: select CONFIG_CRYPTO when selecting DH / KDF apparmor: Make path_max parameter readonly apparmor: fix parameters so that the permission test is bypassed at boot apparmor: fix invalid reference to index variable of iterator line 836 apparmor: use SHASH_DESC_ON_STACK security/apparmor/lsm.c: set debug messages apparmor: fix boolreturn.cocci warnings Smack: Use GFP_KERNEL for smk_netlbl_mls(). smack: fix double free in smack_parse_opts_str() KEYS: add SP800-56A KDF support for DH KEYS: Keyring asymmetric key restrict method with chaining KEYS: Restrict asymmetric key linkage using a specific keychain KEYS: Add a lookup_restriction function for the asymmetric key type KEYS: Add KEYCTL_RESTRICT_KEYRING KEYS: Consistent ordering for __key_link_begin and restrict check KEYS: Add an optional lookup_restriction hook to key_type ...
Diffstat (limited to 'drivers/char/tpm/tpm-dev-common.c')
-rw-r--r--drivers/char/tpm/tpm-dev-common.c148
1 files changed, 148 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c
new file mode 100644
index 000000000000..610638a80383
--- /dev/null
+++ b/drivers/char/tpm/tpm-dev-common.c
@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2004 IBM Corporation
+ * Authors:
+ * Leendert van Doorn <leendert@watson.ibm.com>
+ * Dave Safford <safford@watson.ibm.com>
+ * Reiner Sailer <sailer@watson.ibm.com>
+ * Kylene Hall <kjhall@us.ibm.com>
+ *
+ * Copyright (C) 2013 Obsidian Research Corp
+ * Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
+ *
+ * Device file system interface to the TPM
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ */
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include "tpm.h"
+#include "tpm-dev.h"
+
+static void user_reader_timeout(unsigned long ptr)
+{
+ struct file_priv *priv = (struct file_priv *)ptr;
+
+ pr_warn("TPM user space timeout is deprecated (pid=%d)\n",
+ task_tgid_nr(current));
+
+ schedule_work(&priv->work);
+}
+
+static void timeout_work(struct work_struct *work)
+{
+ struct file_priv *priv = container_of(work, struct file_priv, work);
+
+ mutex_lock(&priv->buffer_mutex);
+ atomic_set(&priv->data_pending, 0);
+ memset(priv->data_buffer, 0, sizeof(priv->data_buffer));
+ mutex_unlock(&priv->buffer_mutex);
+}
+
+void tpm_common_open(struct file *file, struct tpm_chip *chip,
+ struct file_priv *priv)
+{
+ priv->chip = chip;
+ atomic_set(&priv->data_pending, 0);
+ mutex_init(&priv->buffer_mutex);
+ setup_timer(&priv->user_read_timer, user_reader_timeout,
+ (unsigned long)priv);
+ INIT_WORK(&priv->work, timeout_work);
+
+ file->private_data = priv;
+}
+
+ssize_t tpm_common_read(struct file *file, char __user *buf,
+ size_t size, loff_t *off)
+{
+ struct file_priv *priv = file->private_data;
+ ssize_t ret_size;
+ ssize_t orig_ret_size;
+ int rc;
+
+ del_singleshot_timer_sync(&priv->user_read_timer);
+ flush_work(&priv->work);
+ ret_size = atomic_read(&priv->data_pending);
+ if (ret_size > 0) { /* relay data */
+ orig_ret_size = ret_size;
+ if (size < ret_size)
+ ret_size = size;
+
+ mutex_lock(&priv->buffer_mutex);
+ rc = copy_to_user(buf, priv->data_buffer, ret_size);
+ memset(priv->data_buffer, 0, orig_ret_size);
+ if (rc)
+ ret_size = -EFAULT;
+
+ mutex_unlock(&priv->buffer_mutex);
+ }
+
+ atomic_set(&priv->data_pending, 0);
+
+ return ret_size;
+}
+
+ssize_t tpm_common_write(struct file *file, const char __user *buf,
+ size_t size, loff_t *off, struct tpm_space *space)
+{
+ struct file_priv *priv = file->private_data;
+ size_t in_size = size;
+ ssize_t out_size;
+
+ /* Cannot perform a write until the read has cleared either via
+ * tpm_read or a user_read_timer timeout. This also prevents split
+ * buffered writes from blocking here.
+ */
+ if (atomic_read(&priv->data_pending) != 0)
+ return -EBUSY;
+
+ if (in_size > TPM_BUFSIZE)
+ return -E2BIG;
+
+ mutex_lock(&priv->buffer_mutex);
+
+ if (copy_from_user
+ (priv->data_buffer, (void __user *) buf, in_size)) {
+ mutex_unlock(&priv->buffer_mutex);
+ return -EFAULT;
+ }
+
+ /* atomic tpm command send and result receive. We only hold the ops
+ * lock during this period so that the tpm can be unregistered even if
+ * the char dev is held open.
+ */
+ if (tpm_try_get_ops(priv->chip)) {
+ mutex_unlock(&priv->buffer_mutex);
+ return -EPIPE;
+ }
+ out_size = tpm_transmit(priv->chip, space, priv->data_buffer,
+ sizeof(priv->data_buffer), 0);
+
+ tpm_put_ops(priv->chip);
+ if (out_size < 0) {
+ mutex_unlock(&priv->buffer_mutex);
+ return out_size;
+ }
+
+ atomic_set(&priv->data_pending, out_size);
+ mutex_unlock(&priv->buffer_mutex);
+
+ /* Set a timeout by which the reader must come claim the result */
+ mod_timer(&priv->user_read_timer, jiffies + (120 * HZ));
+
+ return in_size;
+}
+
+/*
+ * Called on file close
+ */
+void tpm_common_release(struct file *file, struct file_priv *priv)
+{
+ del_singleshot_timer_sync(&priv->user_read_timer);
+ flush_work(&priv->work);
+ file->private_data = NULL;
+ atomic_set(&priv->data_pending, 0);
+}