[linux-2.6-block.git] / drivers / tty / tty_audit.c

/*
 * Creating audit events from TTY input.
 *
 * Copyright (C) 2007 Red Hat, Inc.  All rights reserved.  This copyrighted
 * material is made available to anyone wishing to use, modify, copy, or
 * redistribute it subject to the terms and conditions of the GNU General
 * Public License v.2.
 *
 * Authors: Miloslav Trmac <mitr@redhat.com>
 */

#include <linux/audit.h>
#include <linux/slab.h>
#include <linux/tty.h>

struct tty_audit_buf {
	atomic_t count;
	struct mutex mutex;	/* Protects all data below */
	int major, minor;	/* The TTY which the data is from */
	unsigned icanon:1;
	size_t valid;
	unsigned char *data;	/* Allocated size N_TTY_BUF_SIZE */
};

static struct tty_audit_buf *tty_audit_buf_alloc(int major, int minor,
						 unsigned icanon)
{
	struct tty_audit_buf *buf;

	buf = kmalloc(sizeof(*buf), GFP_KERNEL);
	if (!buf)
		goto err;
	buf->data = kmalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
	if (!buf->data)
		goto err_buf;
	atomic_set(&buf->count, 1);
	mutex_init(&buf->mutex);
	buf->major = major;
	buf->minor = minor;
	buf->icanon = icanon;
	buf->valid = 0;
	return buf;

err_buf:
	kfree(buf);
err:
	return NULL;
}

static void tty_audit_buf_free(struct tty_audit_buf *buf)
{
	WARN_ON(buf->valid != 0);
	kfree(buf->data);
	kfree(buf);
}

static void tty_audit_buf_put(struct tty_audit_buf *buf)
{
	if (atomic_dec_and_test(&buf->count))
		tty_audit_buf_free(buf);
}

static void tty_audit_log(const char *description, int major, int minor,
			  unsigned char *data, size_t size)
{
	struct audit_buffer *ab;
	struct task_struct *tsk = current;
	pid_t pid = task_pid_nr(tsk);
	uid_t uid = from_kuid(&init_user_ns, task_uid(tsk));
	uid_t loginuid = from_kuid(&init_user_ns, audit_get_loginuid(tsk));
	unsigned int sessionid = audit_get_sessionid(tsk);

	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_TTY);
	if (ab) {
		char name[sizeof(tsk->comm)];

		audit_log_format(ab, "%s pid=%u uid=%u auid=%u ses=%u major=%d"
				 " minor=%d comm=", description, pid, uid,
				 loginuid, sessionid, major, minor);
		get_task_comm(name, tsk);
		audit_log_untrustedstring(ab, name);
		audit_log_format(ab, " data=");
		audit_log_n_hex(ab, data, size);
		audit_log_end(ab);
	}
}

/**
 *	tty_audit_buf_push	-	Push buffered data out
 *
 *	Generate an audit message from the contents of @buf, which is owned by
 *	the current task.  @buf->mutex must be locked.
 */
static void tty_audit_buf_push(struct tty_audit_buf *buf)
{
	if (buf->valid == 0)
		return;
	if (audit_enabled == 0) {
		buf->valid = 0;
		return;
	}
	tty_audit_log("tty", buf->major, buf->minor, buf->data, buf->valid);
	buf->valid = 0;
}

/**
 *	tty_audit_exit	-	Handle a task exit
 *
 *	Make sure all buffered data is written out and deallocate the buffer.
 *	Only needs to be called if current->signal->tty_audit_buf != %NULL.
 */
void tty_audit_exit(void)
{
	struct tty_audit_buf *buf;

	buf = current->signal->tty_audit_buf;
	current->signal->tty_audit_buf = NULL;
	if (!buf)
		return;

	mutex_lock(&buf->mutex);
	tty_audit_buf_push(buf);
	mutex_unlock(&buf->mutex);

	tty_audit_buf_put(buf);
}

/**
 *	tty_audit_fork	-	Copy TTY audit state for a new task
 *
 *	Set up TTY audit state in @sig from current.  @sig needs no locking.
 */
void tty_audit_fork(struct signal_struct *sig)
{
	sig->audit_tty = current->signal->audit_tty;
	sig->audit_tty_log_passwd = current->signal->audit_tty_log_passwd;
}

/**
 *	tty_audit_tiocsti	-	Log TIOCSTI
 */
void tty_audit_tiocsti(struct tty_struct *tty, char ch)
{
	struct tty_audit_buf *buf;
	int major, minor, should_audit;
	unsigned long flags;

	spin_lock_irqsave(&current->sighand->siglock, flags);
	should_audit = current->signal->audit_tty;
	buf = current->signal->tty_audit_buf;
	if (buf)
		atomic_inc(&buf->count);
	spin_unlock_irqrestore(&current->sighand->siglock, flags);

	major = tty->driver->major;
	minor = tty->driver->minor_start + tty->index;
	if (buf) {
		mutex_lock(&buf->mutex);
		if (buf->major == major && buf->minor == minor)
			tty_audit_buf_push(buf);
		mutex_unlock(&buf->mutex);
		tty_audit_buf_put(buf);
	}

	if (should_audit && audit_enabled) {
		kuid_t auid;
		unsigned int sessionid;

		auid = audit_get_loginuid(current);
		sessionid = audit_get_sessionid(current);
		tty_audit_log("ioctl=TIOCSTI", major, minor, &ch, 1);
	}
}

/**
 * tty_audit_push_current -	Flush current's pending audit data
 *
 * Try to lock sighand and get a reference to the tty audit buffer if available.
 * Flush the buffer or return an appropriate error code.
 */
int tty_audit_push_current(void)
{
	struct tty_audit_buf *buf = ERR_PTR(-EPERM);
	struct task_struct *tsk = current;
	unsigned long flags;

	if (!lock_task_sighand(tsk, &flags))
		return -ESRCH;

	if (tsk->signal->audit_tty) {
		buf = tsk->signal->tty_audit_buf;
		if (buf)
			atomic_inc(&buf->count);
	}
	unlock_task_sighand(tsk, &flags);

	/*
	 * Return 0 when signal->audit_tty set
	 * but tsk->signal->tty_audit_buf == NULL.
	 */
	if (!buf || IS_ERR(buf))
		return PTR_ERR(buf);

	mutex_lock(&buf->mutex);
	tty_audit_buf_push(buf);
	mutex_unlock(&buf->mutex);

	tty_audit_buf_put(buf);
	return 0;
}

/**
 *	tty_audit_buf_get	-	Get an audit buffer.
 *
 *	Get an audit buffer for @tty, allocate it if necessary.  Return %NULL
 *	if TTY auditing is disabled or out of memory.  Otherwise, return a new
 *	reference to the buffer.
 */
static struct tty_audit_buf *tty_audit_buf_get(struct tty_struct *tty,
		unsigned icanon)
{
	struct tty_audit_buf *buf, *buf2;
	unsigned long flags;

	buf = NULL;
	buf2 = NULL;
	spin_lock_irqsave(&current->sighand->siglock, flags);
	if (likely(!current->signal->audit_tty))
		goto out;
	buf = current->signal->tty_audit_buf;
	if (buf) {
		atomic_inc(&buf->count);
		goto out;
	}
	spin_unlock_irqrestore(&current->sighand->siglock, flags);

	buf2 = tty_audit_buf_alloc(tty->driver->major,
				   tty->driver->minor_start + tty->index,
				   icanon);
	if (buf2 == NULL) {
		audit_log_lost("out of memory in TTY auditing");
		return NULL;
	}

	spin_lock_irqsave(&current->sighand->siglock, flags);
	if (!current->signal->audit_tty)
		goto out;
	buf = current->signal->tty_audit_buf;
	if (!buf) {
		current->signal->tty_audit_buf = buf2;
		buf = buf2;
		buf2 = NULL;
	}
	atomic_inc(&buf->count);
	/* Fall through */
 out:
	spin_unlock_irqrestore(&current->sighand->siglock, flags);
	if (buf2)
		tty_audit_buf_free(buf2);
	return buf;
}

/**
 *	tty_audit_add_data	-	Add data for TTY auditing.
 *
 *	Audit @data of @size from @tty, if necessary.
 */
void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
			size_t size, unsigned icanon)
{
	struct tty_audit_buf *buf;
	int major, minor;
	int audit_log_tty_passwd;
	unsigned long flags;

	if (unlikely(size == 0))
		return;

	spin_lock_irqsave(&current->sighand->siglock, flags);
	audit_log_tty_passwd = current->signal->audit_tty_log_passwd;
	spin_unlock_irqrestore(&current->sighand->siglock, flags);
	if (!audit_log_tty_passwd && icanon && !L_ECHO(tty))
		return;

	if (tty->driver->type == TTY_DRIVER_TYPE_PTY
	    && tty->driver->subtype == PTY_TYPE_MASTER)
		return;

	buf = tty_audit_buf_get(tty, icanon);
	if (!buf)
		return;

	mutex_lock(&buf->mutex);
	major = tty->driver->major;
	minor = tty->driver->minor_start + tty->index;
	if (buf->major != major || buf->minor != minor
	    || buf->icanon != icanon) {
		tty_audit_buf_push(buf);
		buf->major = major;
		buf->minor = minor;
		buf->icanon = icanon;
	}
	do {
		size_t run;

		run = N_TTY_BUF_SIZE - buf->valid;
		if (run > size)
			run = size;
		memcpy(buf->data + buf->valid, data, run);
		buf->valid += run;
		data += run;
		size -= run;
		if (buf->valid == N_TTY_BUF_SIZE)
			tty_audit_buf_push(buf);
	} while (size != 0);
	mutex_unlock(&buf->mutex);
	tty_audit_buf_put(buf);
}

/**
 *	tty_audit_push	-	Push buffered data out
 *
 *	Make sure no audit data is pending for @tty on the current process.
 */
void tty_audit_push(struct tty_struct *tty)
{
	struct tty_audit_buf *buf;
	unsigned long flags;

	spin_lock_irqsave(&current->sighand->siglock, flags);
	if (likely(!current->signal->audit_tty)) {
		spin_unlock_irqrestore(&current->sighand->siglock, flags);
		return;
	}
	buf = current->signal->tty_audit_buf;
	if (buf)
		atomic_inc(&buf->count);
	spin_unlock_irqrestore(&current->sighand->siglock, flags);

	if (buf) {
		int major, minor;

		major = tty->driver->major;
		minor = tty->driver->minor_start + tty->index;
		mutex_lock(&buf->mutex);
		if (buf->major == major && buf->minor == minor)
			tty_audit_buf_push(buf);
		mutex_unlock(&buf->mutex);
		tty_audit_buf_put(buf);
	}
}
Commit	Line	Data
522ed776 MT	1	/*
	2	* Creating audit events from TTY input.
	3	*
	4	* Copyright (C) 2007 Red Hat, Inc. All rights reserved. This copyrighted
	5	* material is made available to anyone wishing to use, modify, copy, or
	6	* redistribute it subject to the terms and conditions of the GNU General
	7	* Public License v.2.
	8	*
	9	* Authors: Miloslav Trmac <mitr@redhat.com>
	10	*/
	11
	12	#include <linux/audit.h>
5a0e3ad6	13	#include <linux/slab.h>
522ed776 MT	14	#include <linux/tty.h>
	15
	16	struct tty_audit_buf {
	17	atomic_t count;
	18	struct mutex mutex; /* Protects all data below */
	19	int major, minor; /* The TTY which the data is from */
	20	unsigned icanon:1;
	21	size_t valid;
	22	unsigned char data; / Allocated size N_TTY_BUF_SIZE */
	23	};
	24
	25	static struct tty_audit_buf *tty_audit_buf_alloc(int major, int minor,
6c633f27	26	unsigned icanon)
522ed776 MT	27	{
	28	struct tty_audit_buf *buf;
	29
66c6ceae	30	buf = kmalloc(sizeof(*buf), GFP_KERNEL);
522ed776 MT	31	if (!buf)
522ed776 MT	32	goto err;
c481c707	33	buf->data = kmalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
522ed776 MT	34	if (!buf->data)
	35	goto err_buf;
	36	atomic_set(&buf->count, 1);
	37	mutex_init(&buf->mutex);
	38	buf->major = major;
	39	buf->minor = minor;
	40	buf->icanon = icanon;
	41	buf->valid = 0;
	42	return buf;
	43
	44	err_buf:
	45	kfree(buf);
	46	err:
	47	return NULL;
	48	}
	49
	50	static void tty_audit_buf_free(struct tty_audit_buf *buf)
	51	{
	52	WARN_ON(buf->valid != 0);
c481c707	53	kfree(buf->data);
522ed776 MT	54	kfree(buf);
	55	}
	56
	57	static void tty_audit_buf_put(struct tty_audit_buf *buf)
	58	{
	59	if (atomic_dec_and_test(&buf->count))
	60	tty_audit_buf_free(buf);
	61	}
	62
152f497b EP	63	static void tty_audit_log(const char *description, int major, int minor,
152f497b EP	64	unsigned char *data, size_t size)
522ed776 MT	65	{
522ed776 MT	66	struct audit_buffer *ab;
152f497b	67	struct task_struct *tsk = current;
f1dc4867	68	pid_t pid = task_pid_nr(tsk);
152f497b EP	69	uid_t uid = from_kuid(&init_user_ns, task_uid(tsk));
152f497b EP	70	uid_t loginuid = from_kuid(&init_user_ns, audit_get_loginuid(tsk));
4440e854	71	unsigned int sessionid = audit_get_sessionid(tsk);
522ed776	72
522ed776 MT	73	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_TTY);
	74	if (ab) {
	75	char name[sizeof(tsk->comm)];
152f497b EP	76
152f497b EP	77	audit_log_format(ab, "%s pid=%u uid=%u auid=%u ses=%u major=%d"
f1dc4867	78	" minor=%d comm=", description, pid, uid,
152f497b	79	loginuid, sessionid, major, minor);
522ed776 MT	80	get_task_comm(name, tsk);
	81	audit_log_untrustedstring(ab, name);
	82	audit_log_format(ab, " data=");
1e641743	83	audit_log_n_hex(ab, data, size);
522ed776 MT	84	audit_log_end(ab);
522ed776 MT	85	}
1e641743 AV	86	}
	87
	88	/**
	89	* tty_audit_buf_push - Push buffered data out
	90	*
	91	* Generate an audit message from the contents of @buf, which is owned by
152f497b	92	* the current task. @buf->mutex must be locked.
1e641743	93	*/
152f497b	94	static void tty_audit_buf_push(struct tty_audit_buf *buf)
1e641743 AV	95	{
	96	if (buf->valid == 0)
	97	return;
00bff392 XF	98	if (audit_enabled == 0) {
00bff392 XF	99	buf->valid = 0;
1e641743	100	return;
00bff392	101	}
152f497b	102	tty_audit_log("tty", buf->major, buf->minor, buf->data, buf->valid);
522ed776 MT	103	buf->valid = 0;
	104	}
	105
522ed776 MT	106	/**
	107	* tty_audit_exit - Handle a task exit
	108	*
	109	* Make sure all buffered data is written out and deallocate the buffer.
	110	* Only needs to be called if current->signal->tty_audit_buf != %NULL.
	111	*/
	112	void tty_audit_exit(void)
	113	{
	114	struct tty_audit_buf *buf;
	115
522ed776 MT	116	buf = current->signal->tty_audit_buf;
522ed776 MT	117	current->signal->tty_audit_buf = NULL;
522ed776 MT	118	if (!buf)
	119	return;
	120
	121	mutex_lock(&buf->mutex);
152f497b	122	tty_audit_buf_push(buf);
522ed776 MT	123	mutex_unlock(&buf->mutex);
	124
	125	tty_audit_buf_put(buf);
	126	}
	127
	128	/**
	129	* tty_audit_fork - Copy TTY audit state for a new task
	130	*
	131	* Set up TTY audit state in @sig from current. @sig needs no locking.
	132	*/
	133	void tty_audit_fork(struct signal_struct *sig)
	134	{
522ed776	135	sig->audit_tty = current->signal->audit_tty;
46e959ea	136	sig->audit_tty_log_passwd = current->signal->audit_tty_log_passwd;
522ed776 MT	137	}
522ed776 MT	138
1e641743 AV	139	/**
	140	* tty_audit_tiocsti - Log TIOCSTI
	141	*/
	142	void tty_audit_tiocsti(struct tty_struct *tty, char ch)
	143	{
	144	struct tty_audit_buf *buf;
	145	int major, minor, should_audit;
bde02ca8	146	unsigned long flags;
1e641743	147
bde02ca8	148	spin_lock_irqsave(&current->sighand->siglock, flags);
1e641743 AV	149	should_audit = current->signal->audit_tty;
	150	buf = current->signal->tty_audit_buf;
	151	if (buf)
	152	atomic_inc(&buf->count);
bde02ca8	153	spin_unlock_irqrestore(&current->sighand->siglock, flags);
1e641743 AV	154
	155	major = tty->driver->major;
	156	minor = tty->driver->minor_start + tty->index;
	157	if (buf) {
	158	mutex_lock(&buf->mutex);
	159	if (buf->major == major && buf->minor == minor)
152f497b	160	tty_audit_buf_push(buf);
1e641743 AV	161	mutex_unlock(&buf->mutex);
	162	tty_audit_buf_put(buf);
	163	}
	164
	165	if (should_audit && audit_enabled) {
e1760bd5	166	kuid_t auid;
1e641743 AV	167	unsigned int sessionid;
	168
	169	auid = audit_get_loginuid(current);
	170	sessionid = audit_get_sessionid(current);
152f497b	171	tty_audit_log("ioctl=TIOCSTI", major, minor, &ch, 1);
1e641743 AV	172	}
	173	}
	174
522ed776	175	/**
152f497b	176	* tty_audit_push_current - Flush current's pending audit data
3c80fe4a	177	*
152f497b	178	* Try to lock sighand and get a reference to the tty audit buffer if available.
3c80fe4a	179	* Flush the buffer or return an appropriate error code.
522ed776	180	*/
152f497b	181	int tty_audit_push_current(void)
522ed776	182	{
3c80fe4a	183	struct tty_audit_buf *buf = ERR_PTR(-EPERM);
152f497b	184	struct task_struct *tsk = current;
3c80fe4a	185	unsigned long flags;
522ed776	186
3c80fe4a TG	187	if (!lock_task_sighand(tsk, &flags))
	188	return -ESRCH;
	189
	190	if (tsk->signal->audit_tty) {
	191	buf = tsk->signal->tty_audit_buf;
	192	if (buf)
	193	atomic_inc(&buf->count);
	194	}
	195	unlock_task_sighand(tsk, &flags);
	196
	197	/*
	198	* Return 0 when signal->audit_tty set
	199	* but tsk->signal->tty_audit_buf == NULL.
	200	*/
	201	if (!buf \|\| IS_ERR(buf))
	202	return PTR_ERR(buf);
522ed776 MT	203
522ed776 MT	204	mutex_lock(&buf->mutex);
152f497b	205	tty_audit_buf_push(buf);
522ed776 MT	206	mutex_unlock(&buf->mutex);
	207
	208	tty_audit_buf_put(buf);
3c80fe4a	209	return 0;
522ed776 MT	210	}
	211
	212	/**
	213	* tty_audit_buf_get - Get an audit buffer.
	214	*
	215	* Get an audit buffer for @tty, allocate it if necessary. Return %NULL
	216	* if TTY auditing is disabled or out of memory. Otherwise, return a new
	217	* reference to the buffer.
	218	*/
6c633f27 JS	219	static struct tty_audit_buf tty_audit_buf_get(struct tty_struct tty,
6c633f27 JS	220	unsigned icanon)
522ed776 MT	221	{
522ed776 MT	222	struct tty_audit_buf buf, buf2;
bde02ca8	223	unsigned long flags;
522ed776 MT	224
	225	buf = NULL;
	226	buf2 = NULL;
bde02ca8	227	spin_lock_irqsave(&current->sighand->siglock, flags);
522ed776 MT	228	if (likely(!current->signal->audit_tty))
	229	goto out;
	230	buf = current->signal->tty_audit_buf;
	231	if (buf) {
	232	atomic_inc(&buf->count);
	233	goto out;
	234	}
bde02ca8	235	spin_unlock_irqrestore(&current->sighand->siglock, flags);
522ed776 MT	236
	237	buf2 = tty_audit_buf_alloc(tty->driver->major,
	238	tty->driver->minor_start + tty->index,
6c633f27	239	icanon);
522ed776 MT	240	if (buf2 == NULL) {
	241	audit_log_lost("out of memory in TTY auditing");
	242	return NULL;
	243	}
	244
bde02ca8	245	spin_lock_irqsave(&current->sighand->siglock, flags);
522ed776 MT	246	if (!current->signal->audit_tty)
	247	goto out;
	248	buf = current->signal->tty_audit_buf;
	249	if (!buf) {
	250	current->signal->tty_audit_buf = buf2;
	251	buf = buf2;
	252	buf2 = NULL;
	253	}
	254	atomic_inc(&buf->count);
	255	/* Fall through */
	256	out:
bde02ca8	257	spin_unlock_irqrestore(&current->sighand->siglock, flags);
522ed776 MT	258	if (buf2)
	259	tty_audit_buf_free(buf2);
	260	return buf;
	261	}
	262
	263	/**
	264	* tty_audit_add_data - Add data for TTY auditing.
	265	*
	266	* Audit @data of @size from @tty, if necessary.
	267	*/
	268	void tty_audit_add_data(struct tty_struct tty, unsigned char data,
6c633f27	269	size_t size, unsigned icanon)
522ed776 MT	270	{
	271	struct tty_audit_buf *buf;
	272	int major, minor;
46e959ea RGB	273	int audit_log_tty_passwd;
46e959ea RGB	274	unsigned long flags;
522ed776 MT	275
	276	if (unlikely(size == 0))
	277	return;
	278
46e959ea RGB	279	spin_lock_irqsave(&current->sighand->siglock, flags);
	280	audit_log_tty_passwd = current->signal->audit_tty_log_passwd;
	281	spin_unlock_irqrestore(&current->sighand->siglock, flags);
	282	if (!audit_log_tty_passwd && icanon && !L_ECHO(tty))
	283	return;
	284
41126226 MT	285	if (tty->driver->type == TTY_DRIVER_TYPE_PTY
	286	&& tty->driver->subtype == PTY_TYPE_MASTER)
	287	return;
	288
6c633f27	289	buf = tty_audit_buf_get(tty, icanon);
522ed776 MT	290	if (!buf)
	291	return;
	292
	293	mutex_lock(&buf->mutex);
	294	major = tty->driver->major;
	295	minor = tty->driver->minor_start + tty->index;
	296	if (buf->major != major \|\| buf->minor != minor
6c633f27	297	\|\| buf->icanon != icanon) {
152f497b	298	tty_audit_buf_push(buf);
522ed776 MT	299	buf->major = major;
522ed776 MT	300	buf->minor = minor;
6c633f27	301	buf->icanon = icanon;
522ed776 MT	302	}
	303	do {
	304	size_t run;
	305
	306	run = N_TTY_BUF_SIZE - buf->valid;
	307	if (run > size)
	308	run = size;
	309	memcpy(buf->data + buf->valid, data, run);
	310	buf->valid += run;
	311	data += run;
	312	size -= run;
	313	if (buf->valid == N_TTY_BUF_SIZE)
152f497b	314	tty_audit_buf_push(buf);
522ed776 MT	315	} while (size != 0);
	316	mutex_unlock(&buf->mutex);
	317	tty_audit_buf_put(buf);
	318	}
	319
	320	/**
	321	* tty_audit_push - Push buffered data out
	322	*
	323	* Make sure no audit data is pending for @tty on the current process.
	324	*/
	325	void tty_audit_push(struct tty_struct *tty)
	326	{
	327	struct tty_audit_buf *buf;
bde02ca8	328	unsigned long flags;
522ed776	329
bde02ca8	330	spin_lock_irqsave(&current->sighand->siglock, flags);
522ed776	331	if (likely(!current->signal->audit_tty)) {
bde02ca8	332	spin_unlock_irqrestore(&current->sighand->siglock, flags);
522ed776 MT	333	return;
	334	}
	335	buf = current->signal->tty_audit_buf;
	336	if (buf)
	337	atomic_inc(&buf->count);
bde02ca8	338	spin_unlock_irqrestore(&current->sighand->siglock, flags);
522ed776 MT	339
	340	if (buf) {
	341	int major, minor;
	342
	343	major = tty->driver->major;
	344	minor = tty->driver->minor_start + tty->index;
	345	mutex_lock(&buf->mutex);
	346	if (buf->major == major && buf->minor == minor)
152f497b	347	tty_audit_buf_push(buf);
522ed776 MT	348	mutex_unlock(&buf->mutex);
	349	tty_audit_buf_put(buf);
	350	}
	351	}