[lttng-modules.git] / lib / ringbuffer / ring_buffer_vfs.c

/* SPDX-License-Identifier: (GPL-2.0-only OR LGPL-2.1-only)
 *
 * ring_buffer_vfs.c
 *
 * Ring Buffer VFS file operations.
 *
 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 */

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/compat.h>

#include <ringbuffer/backend.h>
#include <ringbuffer/frontend.h>
#include <ringbuffer/vfs.h>
#include <wrapper/poll.h>
#include <lttng-tracer.h>

static int put_ulong(unsigned long val, unsigned long arg)
{
	return put_user(val, (unsigned long __user *)arg);
}

#ifdef CONFIG_COMPAT
static int compat_put_ulong(compat_ulong_t val, unsigned long arg)
{
	return put_user(val, (compat_ulong_t __user *)compat_ptr(arg));
}
#endif

/*
 * This is not used by anonymous file descriptors. This code is left
 * there if we ever want to implement an inode with open() operation.
 */
int lib_ring_buffer_open(struct inode *inode, struct file *file,
		struct lib_ring_buffer *buf)
{
	int ret;

	if (!buf)
		return -EINVAL;

	ret = lib_ring_buffer_open_read(buf);
	if (ret)
		return ret;

	ret = nonseekable_open(inode, file);
	if (ret)
		goto release_read;
	return 0;

release_read:
	lib_ring_buffer_release_read(buf);
	return ret;
}
EXPORT_SYMBOL_GPL(lib_ring_buffer_open);

/**
 *	vfs_lib_ring_buffer_open - ring buffer open file operation
 *	@inode: opened inode
 *	@file: opened file
 *
 *	Open implementation. Makes sure only one open instance of a buffer is
 *	done at a given moment.
 */
static
int vfs_lib_ring_buffer_open(struct inode *inode, struct file *file)
{
	struct lib_ring_buffer *buf = inode->i_private;

	file->private_data = buf;
	return lib_ring_buffer_open(inode, file, buf);
}

int lib_ring_buffer_release(struct inode *inode, struct file *file,
		struct lib_ring_buffer *buf)
{
	lib_ring_buffer_release_read(buf);

	return 0;
}
EXPORT_SYMBOL_GPL(lib_ring_buffer_release);

/**
 *	vfs_lib_ring_buffer_release - ring buffer release file operation
 *	@inode: opened inode
 *	@file: opened file
 *
 *	Release implementation.
 */
static
int vfs_lib_ring_buffer_release(struct inode *inode, struct file *file)
{
	struct lib_ring_buffer *buf = file->private_data;

	return lib_ring_buffer_release(inode, file, buf);
}

unsigned int lib_ring_buffer_poll(struct file *filp, poll_table *wait,
		struct lib_ring_buffer *buf)
{
	unsigned int mask = 0;
	struct channel *chan = buf->backend.chan;
	const struct lib_ring_buffer_config *config = &chan->backend.config;
	int finalized, disabled;

	if (filp->f_mode & FMODE_READ) {
		poll_wait_set_exclusive(wait);
		poll_wait(filp, &buf->read_wait, wait);

		finalized = lib_ring_buffer_is_finalized(config, buf);
		disabled = lib_ring_buffer_channel_is_disabled(chan);

		/*
		 * lib_ring_buffer_is_finalized() contains a smp_rmb() ordering
		 * finalized load before offsets loads.
		 */
		WARN_ON(atomic_long_read(&buf->active_readers) != 1);
retry:
		if (disabled)
			return POLLERR;

		if (subbuf_trunc(lib_ring_buffer_get_offset(config, buf), chan)
		  - subbuf_trunc(lib_ring_buffer_get_consumed(config, buf), chan)
		  == 0) {
			if (finalized)
				return POLLHUP;
			else {
				/*
				 * The memory barriers
				 * __wait_event()/wake_up_interruptible() take
				 * care of "raw_spin_is_locked" memory ordering.
				 */
				if (raw_spin_is_locked(&buf->raw_tick_nohz_spinlock))
					goto retry;
				else
					return 0;
			}
		} else {
			if (subbuf_trunc(lib_ring_buffer_get_offset(config, buf),
					 chan)
			  - subbuf_trunc(lib_ring_buffer_get_consumed(config, buf),
					 chan)
			  >= chan->backend.buf_size)
				return POLLPRI | POLLRDBAND;
			else
				return POLLIN | POLLRDNORM;
		}
	}
	return mask;
}
EXPORT_SYMBOL_GPL(lib_ring_buffer_poll);

/**
 *	vfs_lib_ring_buffer_poll - ring buffer poll file operation
 *	@filp: the file
 *	@wait: poll table
 *
 *	Poll implementation.
 */
static
unsigned int vfs_lib_ring_buffer_poll(struct file *filp, poll_table *wait)
{
	struct lib_ring_buffer *buf = filp->private_data;

	return lib_ring_buffer_poll(filp, wait, buf);
}

long lib_ring_buffer_ioctl(struct file *filp, unsigned int cmd,
		unsigned long arg, struct lib_ring_buffer *buf)
{
	struct channel *chan = buf->backend.chan;
	const struct lib_ring_buffer_config *config = &chan->backend.config;

	if (lib_ring_buffer_channel_is_disabled(chan))
		return -EIO;

	switch (cmd) {
	case RING_BUFFER_SNAPSHOT:
		return lib_ring_buffer_snapshot(buf, &buf->cons_snapshot,
					    &buf->prod_snapshot);
	case RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS:
		return lib_ring_buffer_snapshot_sample_positions(buf,
				&buf->cons_snapshot, &buf->prod_snapshot);
	case RING_BUFFER_SNAPSHOT_GET_CONSUMED:
		return put_ulong(buf->cons_snapshot, arg);
	case RING_BUFFER_SNAPSHOT_GET_PRODUCED:
		return put_ulong(buf->prod_snapshot, arg);
	case RING_BUFFER_GET_SUBBUF:
	{
		unsigned long uconsume;
		long ret;

		ret = get_user(uconsume, (unsigned long __user *) arg);
		if (ret)
			return ret; /* will return -EFAULT */
		ret = lib_ring_buffer_get_subbuf(buf, uconsume);
		if (!ret) {
			/* Set file position to zero at each successful "get" */
			filp->f_pos = 0;
		}
		return ret;
	}
	case RING_BUFFER_PUT_SUBBUF:
		lib_ring_buffer_put_subbuf(buf);
		return 0;

	case RING_BUFFER_GET_NEXT_SUBBUF:
	{
		long ret;

		ret = lib_ring_buffer_get_next_subbuf(buf);
		if (!ret) {
			/* Set file position to zero at each successful "get" */
			filp->f_pos = 0;
		}
		return ret;
	}
	case RING_BUFFER_PUT_NEXT_SUBBUF:
		lib_ring_buffer_put_next_subbuf(buf);
		return 0;
	case RING_BUFFER_GET_SUBBUF_SIZE:
		return put_ulong(lib_ring_buffer_get_read_data_size(config, buf),
				 arg);
	case RING_BUFFER_GET_PADDED_SUBBUF_SIZE:
	{
		unsigned long size;

		size = lib_ring_buffer_get_read_data_size(config, buf);
		size = PAGE_ALIGN(size);
		return put_ulong(size, arg);
	}
	case RING_BUFFER_GET_MAX_SUBBUF_SIZE:
		return put_ulong(chan->backend.subbuf_size, arg);
	case RING_BUFFER_GET_MMAP_LEN:
	{
		unsigned long mmap_buf_len;

		if (config->output != RING_BUFFER_MMAP)
			return -EINVAL;
		mmap_buf_len = chan->backend.buf_size;
		if (chan->backend.extra_reader_sb)
			mmap_buf_len += chan->backend.subbuf_size;
		if (mmap_buf_len > INT_MAX)
			return -EFBIG;
		return put_ulong(mmap_buf_len, arg);
	}
	case RING_BUFFER_GET_MMAP_READ_OFFSET:
	{
		unsigned long sb_bindex;

		if (config->output != RING_BUFFER_MMAP)
			return -EINVAL;
		sb_bindex = subbuffer_id_get_index(config,
						   buf->backend.buf_rsb.id);
		return put_ulong(buf->backend.array[sb_bindex]->mmap_offset,
				 arg);
	}
	case RING_BUFFER_FLUSH:
		lib_ring_buffer_switch_remote(buf);
		return 0;
	case RING_BUFFER_FLUSH_EMPTY:
		lib_ring_buffer_switch_remote_empty(buf);
		return 0;
	case RING_BUFFER_CLEAR:
		lib_ring_buffer_clear(buf);
		return 0;
	default:
		return -ENOIOCTLCMD;
	}
}
EXPORT_SYMBOL_GPL(lib_ring_buffer_ioctl);

/**
 *	vfs_lib_ring_buffer_ioctl - control ring buffer reader synchronization
 *
 *	@filp: the file
 *	@cmd: the command
 *	@arg: command arg
 *
 *	This ioctl implements commands necessary for producer/consumer
 *	and flight recorder reader interaction :
 *	RING_BUFFER_GET_NEXT_SUBBUF
 *		Get the next sub-buffer that can be read. It never blocks.
 *	RING_BUFFER_PUT_NEXT_SUBBUF
 *		Release the currently read sub-buffer.
 *	RING_BUFFER_GET_SUBBUF_SIZE
 *		returns the size of the current sub-buffer.
 *	RING_BUFFER_GET_MAX_SUBBUF_SIZE
 *		returns the maximum size for sub-buffers.
 *	RING_BUFFER_GET_NUM_SUBBUF
 *		returns the number of reader-visible sub-buffers in the per cpu
 *              channel (for mmap).
 *      RING_BUFFER_GET_MMAP_READ_OFFSET
 *              returns the offset of the subbuffer belonging to the reader.
 *              Should only be used for mmap clients.
 */
static
long vfs_lib_ring_buffer_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
	struct lib_ring_buffer *buf = filp->private_data;

	return lib_ring_buffer_ioctl(filp, cmd, arg, buf);
}

#ifdef CONFIG_COMPAT
long lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd,
		unsigned long arg, struct lib_ring_buffer *buf)
{
	struct channel *chan = buf->backend.chan;
	const struct lib_ring_buffer_config *config = &chan->backend.config;

	if (lib_ring_buffer_channel_is_disabled(chan))
		return -EIO;

	switch (cmd) {
	case RING_BUFFER_COMPAT_SNAPSHOT:
		return lib_ring_buffer_snapshot(buf, &buf->cons_snapshot,
						&buf->prod_snapshot);
	case RING_BUFFER_COMPAT_SNAPSHOT_SAMPLE_POSITIONS:
		return lib_ring_buffer_snapshot_sample_positions(buf,
				&buf->cons_snapshot, &buf->prod_snapshot);
	case RING_BUFFER_COMPAT_SNAPSHOT_GET_CONSUMED:
		return compat_put_ulong(buf->cons_snapshot, arg);
	case RING_BUFFER_COMPAT_SNAPSHOT_GET_PRODUCED:
		return compat_put_ulong(buf->prod_snapshot, arg);
	case RING_BUFFER_COMPAT_GET_SUBBUF:
	{
		__u32 uconsume;
		unsigned long consume;
		long ret;

		ret = get_user(uconsume, (__u32 __user *) arg);
		if (ret)
			return ret; /* will return -EFAULT */
		consume = buf->cons_snapshot;
		consume &= ~0xFFFFFFFFL;
		consume |= uconsume;
		ret = lib_ring_buffer_get_subbuf(buf, consume);
		if (!ret) {
			/* Set file position to zero at each successful "get" */
			filp->f_pos = 0;
		}
		return ret;
	}
	case RING_BUFFER_COMPAT_PUT_SUBBUF:
		lib_ring_buffer_put_subbuf(buf);
		return 0;

	case RING_BUFFER_COMPAT_GET_NEXT_SUBBUF:
	{
		long ret;

		ret = lib_ring_buffer_get_next_subbuf(buf);
		if (!ret) {
			/* Set file position to zero at each successful "get" */
			filp->f_pos = 0;
		}
		return ret;
	}
	case RING_BUFFER_COMPAT_PUT_NEXT_SUBBUF:
		lib_ring_buffer_put_next_subbuf(buf);
		return 0;
	case RING_BUFFER_COMPAT_GET_SUBBUF_SIZE:
	{
		unsigned long data_size;

		data_size = lib_ring_buffer_get_read_data_size(config, buf);
		if (data_size > UINT_MAX)
			return -EFBIG;
		return compat_put_ulong(data_size, arg);
	}
	case RING_BUFFER_COMPAT_GET_PADDED_SUBBUF_SIZE:
	{
		unsigned long size;

		size = lib_ring_buffer_get_read_data_size(config, buf);
		size = PAGE_ALIGN(size);
		if (size > UINT_MAX)
			return -EFBIG;
		return compat_put_ulong(size, arg);
	}
	case RING_BUFFER_COMPAT_GET_MAX_SUBBUF_SIZE:
		if (chan->backend.subbuf_size > UINT_MAX)
			return -EFBIG;
		return compat_put_ulong(chan->backend.subbuf_size, arg);
	case RING_BUFFER_COMPAT_GET_MMAP_LEN:
	{
		unsigned long mmap_buf_len;

		if (config->output != RING_BUFFER_MMAP)
			return -EINVAL;
		mmap_buf_len = chan->backend.buf_size;
		if (chan->backend.extra_reader_sb)
			mmap_buf_len += chan->backend.subbuf_size;
		if (mmap_buf_len > UINT_MAX)
			return -EFBIG;
		return compat_put_ulong(mmap_buf_len, arg);
	}
	case RING_BUFFER_COMPAT_GET_MMAP_READ_OFFSET:
	{
		unsigned long sb_bindex, read_offset;

		if (config->output != RING_BUFFER_MMAP)
			return -EINVAL;
		sb_bindex = subbuffer_id_get_index(config,
						   buf->backend.buf_rsb.id);
		read_offset = buf->backend.array[sb_bindex]->mmap_offset;
		if (read_offset > UINT_MAX)
			return -EINVAL;
		return compat_put_ulong(read_offset, arg);
	}
	case RING_BUFFER_COMPAT_FLUSH:
		lib_ring_buffer_switch_remote(buf);
		return 0;
	case RING_BUFFER_COMPAT_FLUSH_EMPTY:
		lib_ring_buffer_switch_remote_empty(buf);
		return 0;
	case RING_BUFFER_COMPAT_CLEAR:
		lib_ring_buffer_clear(buf);
		return 0;
	default:
		return -ENOIOCTLCMD;
	}
}
EXPORT_SYMBOL_GPL(lib_ring_buffer_compat_ioctl);

static
long vfs_lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd,
				  unsigned long arg)
{
	struct lib_ring_buffer *buf = filp->private_data;

	return lib_ring_buffer_compat_ioctl(filp, cmd, arg, buf);
}
#endif

const struct file_operations lib_ring_buffer_file_operations = {
	.owner = THIS_MODULE,
	.open = vfs_lib_ring_buffer_open,
	.release = vfs_lib_ring_buffer_release,
	.poll = vfs_lib_ring_buffer_poll,
	.splice_read = vfs_lib_ring_buffer_splice_read,
	.mmap = vfs_lib_ring_buffer_mmap,
	.unlocked_ioctl = vfs_lib_ring_buffer_ioctl,
	.llseek = vfs_lib_ring_buffer_no_llseek,
#ifdef CONFIG_COMPAT
	.compat_ioctl = vfs_lib_ring_buffer_compat_ioctl,
#endif
};
EXPORT_SYMBOL_GPL(lib_ring_buffer_file_operations);

MODULE_LICENSE("GPL and additional rights");
MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
MODULE_DESCRIPTION("LTTng ring buffer library");
MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
	__stringify(LTTNG_MODULES_MINOR_VERSION) "."
	__stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
	LTTNG_MODULES_EXTRAVERSION);
Commit	Line	Data
b7cdc182	1	/* SPDX-License-Identifier: (GPL-2.0-only OR LGPL-2.1-only)
9f36eaed	2	*
f3bc08c5 MD	3	* ring_buffer_vfs.c
f3bc08c5 MD	4	*
f3bc08c5 MD	5	* Ring Buffer VFS file operations.
f3bc08c5 MD	6	*
886d51a3	7	* Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
f3bc08c5 MD	8	*/
	9
	10	#include <linux/module.h>
	11	#include <linux/fs.h>
	12	#include <linux/compat.h>
	13
24591303 MD	14	#include <ringbuffer/backend.h>
	15	#include <ringbuffer/frontend.h>
	16	#include <ringbuffer/vfs.h>
c075712b MD	17	#include <wrapper/poll.h>
c075712b MD	18	#include <lttng-tracer.h>
f3bc08c5 MD	19
	20	static int put_ulong(unsigned long val, unsigned long arg)
	21	{
	22	return put_user(val, (unsigned long __user *)arg);
	23	}
	24
	25	#ifdef CONFIG_COMPAT
	26	static int compat_put_ulong(compat_ulong_t val, unsigned long arg)
	27	{
	28	return put_user(val, (compat_ulong_t __user *)compat_ptr(arg));
	29	}
	30	#endif
	31
b3b8072b MD	32	/*
	33	* This is not used by anonymous file descriptors. This code is left
	34	* there if we ever want to implement an inode with open() operation.
	35	*/
d83004aa JD	36	int lib_ring_buffer_open(struct inode inode, struct file file,
d83004aa JD	37	struct lib_ring_buffer *buf)
f3bc08c5	38	{
f3bc08c5 MD	39	int ret;
f3bc08c5 MD	40
733ce41d MD	41	if (!buf)
	42	return -EINVAL;
	43
f3bc08c5 MD	44	ret = lib_ring_buffer_open_read(buf);
	45	if (ret)
	46	return ret;
	47
f3bc08c5 MD	48	ret = nonseekable_open(inode, file);
	49	if (ret)
	50	goto release_read;
	51	return 0;
	52
	53	release_read:
	54	lib_ring_buffer_release_read(buf);
	55	return ret;
	56	}
d83004aa	57	EXPORT_SYMBOL_GPL(lib_ring_buffer_open);
f3bc08c5 MD	58
f3bc08c5 MD	59	/**
d83004aa	60	* vfs_lib_ring_buffer_open - ring buffer open file operation
f3bc08c5 MD	61	* @inode: opened inode
	62	* @file: opened file
	63	*
d83004aa JD	64	* Open implementation. Makes sure only one open instance of a buffer is
d83004aa JD	65	* done at a given moment.
f3bc08c5	66	*/
d83004aa JD	67	static
d83004aa JD	68	int vfs_lib_ring_buffer_open(struct inode inode, struct file file)
f3bc08c5	69	{
d83004aa JD	70	struct lib_ring_buffer *buf = inode->i_private;
	71
	72	file->private_data = buf;
	73	return lib_ring_buffer_open(inode, file, buf);
	74	}
f3bc08c5	75
d83004aa JD	76	int lib_ring_buffer_release(struct inode inode, struct file file,
	77	struct lib_ring_buffer *buf)
	78	{
f3bc08c5 MD	79	lib_ring_buffer_release_read(buf);
	80
	81	return 0;
	82	}
d83004aa	83	EXPORT_SYMBOL_GPL(lib_ring_buffer_release);
f3bc08c5 MD	84
f3bc08c5 MD	85	/**
d83004aa JD	86	* vfs_lib_ring_buffer_release - ring buffer release file operation
	87	* @inode: opened inode
	88	* @file: opened file
f3bc08c5	89	*
d83004aa	90	* Release implementation.
f3bc08c5	91	*/
d83004aa JD	92	static
	93	int vfs_lib_ring_buffer_release(struct inode inode, struct file file)
	94	{
	95	struct lib_ring_buffer *buf = file->private_data;
	96
	97	return lib_ring_buffer_release(inode, file, buf);
	98	}
	99
	100	unsigned int lib_ring_buffer_poll(struct file filp, poll_table wait,
	101	struct lib_ring_buffer *buf)
f3bc08c5 MD	102	{
f3bc08c5 MD	103	unsigned int mask = 0;
f3bc08c5	104	struct channel *chan = buf->backend.chan;
5a8fd222	105	const struct lib_ring_buffer_config *config = &chan->backend.config;
254ec7bc	106	int finalized, disabled;
f3bc08c5 MD	107
f3bc08c5 MD	108	if (filp->f_mode & FMODE_READ) {
a33e44a6	109	poll_wait_set_exclusive(wait);
f3bc08c5 MD	110	poll_wait(filp, &buf->read_wait, wait);
	111
	112	finalized = lib_ring_buffer_is_finalized(config, buf);
254ec7bc MD	113	disabled = lib_ring_buffer_channel_is_disabled(chan);
254ec7bc MD	114
f3bc08c5 MD	115	/*
	116	* lib_ring_buffer_is_finalized() contains a smp_rmb() ordering
	117	* finalized load before offsets loads.
	118	*/
	119	WARN_ON(atomic_long_read(&buf->active_readers) != 1);
	120	retry:
254ec7bc MD	121	if (disabled)
	122	return POLLERR;
	123
f3bc08c5 MD	124	if (subbuf_trunc(lib_ring_buffer_get_offset(config, buf), chan)
	125	- subbuf_trunc(lib_ring_buffer_get_consumed(config, buf), chan)
	126	== 0) {
	127	if (finalized)
	128	return POLLHUP;
	129	else {
	130	/*
	131	* The memory barriers
	132	* __wait_event()/wake_up_interruptible() take
	133	* care of "raw_spin_is_locked" memory ordering.
	134	*/
	135	if (raw_spin_is_locked(&buf->raw_tick_nohz_spinlock))
	136	goto retry;
	137	else
	138	return 0;
	139	}
	140	} else {
	141	if (subbuf_trunc(lib_ring_buffer_get_offset(config, buf),
	142	chan)
	143	- subbuf_trunc(lib_ring_buffer_get_consumed(config, buf),
	144	chan)
	145	>= chan->backend.buf_size)
	146	return POLLPRI \| POLLRDBAND;
	147	else
	148	return POLLIN \| POLLRDNORM;
	149	}
	150	}
	151	return mask;
	152	}
d83004aa	153	EXPORT_SYMBOL_GPL(lib_ring_buffer_poll);
f3bc08c5 MD	154
f3bc08c5 MD	155	/**
d83004aa	156	* vfs_lib_ring_buffer_poll - ring buffer poll file operation
f3bc08c5	157	* @filp: the file
d83004aa	158	* @wait: poll table
f3bc08c5	159	*
d83004aa	160	* Poll implementation.
f3bc08c5	161	*/
d83004aa JD	162	static
d83004aa JD	163	unsigned int vfs_lib_ring_buffer_poll(struct file filp, poll_table wait)
f3bc08c5 MD	164	{
f3bc08c5 MD	165	struct lib_ring_buffer *buf = filp->private_data;
d83004aa JD	166
	167	return lib_ring_buffer_poll(filp, wait, buf);
	168	}
	169
	170	long lib_ring_buffer_ioctl(struct file *filp, unsigned int cmd,
	171	unsigned long arg, struct lib_ring_buffer *buf)
	172	{
f3bc08c5	173	struct channel *chan = buf->backend.chan;
5a8fd222	174	const struct lib_ring_buffer_config *config = &chan->backend.config;
f3bc08c5	175
254ec7bc MD	176	if (lib_ring_buffer_channel_is_disabled(chan))
	177	return -EIO;
	178
f3bc08c5 MD	179	switch (cmd) {
	180	case RING_BUFFER_SNAPSHOT:
	181	return lib_ring_buffer_snapshot(buf, &buf->cons_snapshot,
	182	&buf->prod_snapshot);
4dce5a48 JG	183	case RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS:
	184	return lib_ring_buffer_snapshot_sample_positions(buf,
	185	&buf->cons_snapshot, &buf->prod_snapshot);
f3bc08c5 MD	186	case RING_BUFFER_SNAPSHOT_GET_CONSUMED:
	187	return put_ulong(buf->cons_snapshot, arg);
	188	case RING_BUFFER_SNAPSHOT_GET_PRODUCED:
	189	return put_ulong(buf->prod_snapshot, arg);
	190	case RING_BUFFER_GET_SUBBUF:
	191	{
	192	unsigned long uconsume;
	193	long ret;
	194
	195	ret = get_user(uconsume, (unsigned long __user *) arg);
	196	if (ret)
	197	return ret; /* will return -EFAULT */
	198	ret = lib_ring_buffer_get_subbuf(buf, uconsume);
	199	if (!ret) {
	200	/* Set file position to zero at each successful "get" */
	201	filp->f_pos = 0;
	202	}
	203	return ret;
	204	}
	205	case RING_BUFFER_PUT_SUBBUF:
	206	lib_ring_buffer_put_subbuf(buf);
	207	return 0;
	208
	209	case RING_BUFFER_GET_NEXT_SUBBUF:
	210	{
	211	long ret;
	212
	213	ret = lib_ring_buffer_get_next_subbuf(buf);
	214	if (!ret) {
	215	/* Set file position to zero at each successful "get" */
	216	filp->f_pos = 0;
	217	}
	218	return ret;
	219	}
	220	case RING_BUFFER_PUT_NEXT_SUBBUF:
	221	lib_ring_buffer_put_next_subbuf(buf);
	222	return 0;
	223	case RING_BUFFER_GET_SUBBUF_SIZE:
	224	return put_ulong(lib_ring_buffer_get_read_data_size(config, buf),
	225	arg);
	226	case RING_BUFFER_GET_PADDED_SUBBUF_SIZE:
	227	{
	228	unsigned long size;
	229
	230	size = lib_ring_buffer_get_read_data_size(config, buf);
	231	size = PAGE_ALIGN(size);
	232	return put_ulong(size, arg);
	233	}
	234	case RING_BUFFER_GET_MAX_SUBBUF_SIZE:
	235	return put_ulong(chan->backend.subbuf_size, arg);
	236	case RING_BUFFER_GET_MMAP_LEN:
	237	{
	238	unsigned long mmap_buf_len;
	239
	240	if (config->output != RING_BUFFER_MMAP)
	241	return -EINVAL;
	242	mmap_buf_len = chan->backend.buf_size;
	243	if (chan->backend.extra_reader_sb)
	244	mmap_buf_len += chan->backend.subbuf_size;
	245	if (mmap_buf_len > INT_MAX)
	246	return -EFBIG;
	247	return put_ulong(mmap_buf_len, arg);
	248	}
	249	case RING_BUFFER_GET_MMAP_READ_OFFSET:
250	{
251	unsigned long sb_bindex;
252
253	if (config->output != RING_BUFFER_MMAP)
254	return -EINVAL;
255	sb_bindex = subbuffer_id_get_index(config,
256	buf->backend.buf_rsb.id);
257	return put_ulong(buf->backend.array[sb_bindex]->mmap_offset,
258	arg);
259	}
5c055266	260	case RING_BUFFER_FLUSH:
5e391252	261	lib_ring_buffer_switch_remote(buf);
5c055266	262	return 0;
c6f05468 MD	263	case RING_BUFFER_FLUSH_EMPTY:
	264	lib_ring_buffer_switch_remote_empty(buf);
	265	return 0;
c245d0d3 MD	266	case RING_BUFFER_CLEAR:
	267	lib_ring_buffer_clear(buf);
	268	return 0;
f3bc08c5 MD	269	default:
	270	return -ENOIOCTLCMD;
	271	}
	272	}
d83004aa JD	273	EXPORT_SYMBOL_GPL(lib_ring_buffer_ioctl);
	274
	275	/**
	276	* vfs_lib_ring_buffer_ioctl - control ring buffer reader synchronization
	277	*
	278	* @filp: the file
	279	* @cmd: the command
	280	* @arg: command arg
	281	*
	282	* This ioctl implements commands necessary for producer/consumer
	283	* and flight recorder reader interaction :
	284	* RING_BUFFER_GET_NEXT_SUBBUF
	285	* Get the next sub-buffer that can be read. It never blocks.
	286	* RING_BUFFER_PUT_NEXT_SUBBUF
	287	* Release the currently read sub-buffer.
	288	* RING_BUFFER_GET_SUBBUF_SIZE
	289	* returns the size of the current sub-buffer.
	290	* RING_BUFFER_GET_MAX_SUBBUF_SIZE
	291	* returns the maximum size for sub-buffers.
	292	* RING_BUFFER_GET_NUM_SUBBUF
	293	* returns the number of reader-visible sub-buffers in the per cpu
	294	* channel (for mmap).
	295	* RING_BUFFER_GET_MMAP_READ_OFFSET
	296	* returns the offset of the subbuffer belonging to the reader.
	297	* Should only be used for mmap clients.
	298	*/
	299	static
	300	long vfs_lib_ring_buffer_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
	301	{
	302	struct lib_ring_buffer *buf = filp->private_data;
	303
	304	return lib_ring_buffer_ioctl(filp, cmd, arg, buf);
	305	}
f3bc08c5 MD	306
	307	#ifdef CONFIG_COMPAT
	308	long lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd,
d83004aa	309	unsigned long arg, struct lib_ring_buffer *buf)
f3bc08c5	310	{
f3bc08c5	311	struct channel *chan = buf->backend.chan;
5a8fd222	312	const struct lib_ring_buffer_config *config = &chan->backend.config;
254ec7bc MD	313
	314	if (lib_ring_buffer_channel_is_disabled(chan))
	315	return -EIO;
f3bc08c5 MD	316
f3bc08c5 MD	317	switch (cmd) {
216f7feb	318	case RING_BUFFER_COMPAT_SNAPSHOT:
f3bc08c5 MD	319	return lib_ring_buffer_snapshot(buf, &buf->cons_snapshot,
f3bc08c5 MD	320	&buf->prod_snapshot);
4dce5a48 JG	321	case RING_BUFFER_COMPAT_SNAPSHOT_SAMPLE_POSITIONS:
	322	return lib_ring_buffer_snapshot_sample_positions(buf,
	323	&buf->cons_snapshot, &buf->prod_snapshot);
216f7feb	324	case RING_BUFFER_COMPAT_SNAPSHOT_GET_CONSUMED:
f3bc08c5	325	return compat_put_ulong(buf->cons_snapshot, arg);
216f7feb	326	case RING_BUFFER_COMPAT_SNAPSHOT_GET_PRODUCED:
f3bc08c5	327	return compat_put_ulong(buf->prod_snapshot, arg);
216f7feb	328	case RING_BUFFER_COMPAT_GET_SUBBUF:
f3bc08c5 MD	329	{
	330	__u32 uconsume;
	331	unsigned long consume;
	332	long ret;
	333
	334	ret = get_user(uconsume, (__u32 __user *) arg);
	335	if (ret)
	336	return ret; /* will return -EFAULT */
	337	consume = buf->cons_snapshot;
	338	consume &= ~0xFFFFFFFFL;
	339	consume \|= uconsume;
	340	ret = lib_ring_buffer_get_subbuf(buf, consume);
	341	if (!ret) {
	342	/* Set file position to zero at each successful "get" */
	343	filp->f_pos = 0;
	344	}
	345	return ret;
	346	}
216f7feb	347	case RING_BUFFER_COMPAT_PUT_SUBBUF:
f3bc08c5 MD	348	lib_ring_buffer_put_subbuf(buf);
	349	return 0;
	350
216f7feb	351	case RING_BUFFER_COMPAT_GET_NEXT_SUBBUF:
f3bc08c5 MD	352	{
	353	long ret;
	354
	355	ret = lib_ring_buffer_get_next_subbuf(buf);
	356	if (!ret) {
	357	/* Set file position to zero at each successful "get" */
	358	filp->f_pos = 0;
	359	}
	360	return ret;
	361	}
216f7feb	362	case RING_BUFFER_COMPAT_PUT_NEXT_SUBBUF:
f3bc08c5 MD	363	lib_ring_buffer_put_next_subbuf(buf);
f3bc08c5 MD	364	return 0;
216f7feb	365	case RING_BUFFER_COMPAT_GET_SUBBUF_SIZE:
f3bc08c5 MD	366	{
	367	unsigned long data_size;
	368
	369	data_size = lib_ring_buffer_get_read_data_size(config, buf);
	370	if (data_size > UINT_MAX)
	371	return -EFBIG;
4343ec8e	372	return compat_put_ulong(data_size, arg);
f3bc08c5	373	}
216f7feb	374	case RING_BUFFER_COMPAT_GET_PADDED_SUBBUF_SIZE:
f3bc08c5 MD	375	{
	376	unsigned long size;
	377
	378	size = lib_ring_buffer_get_read_data_size(config, buf);
	379	size = PAGE_ALIGN(size);
	380	if (size > UINT_MAX)
	381	return -EFBIG;
4343ec8e	382	return compat_put_ulong(size, arg);
f3bc08c5	383	}
216f7feb	384	case RING_BUFFER_COMPAT_GET_MAX_SUBBUF_SIZE:
f3bc08c5 MD	385	if (chan->backend.subbuf_size > UINT_MAX)
f3bc08c5 MD	386	return -EFBIG;
4343ec8e	387	return compat_put_ulong(chan->backend.subbuf_size, arg);
216f7feb	388	case RING_BUFFER_COMPAT_GET_MMAP_LEN:
f3bc08c5 MD	389	{
	390	unsigned long mmap_buf_len;
	391
	392	if (config->output != RING_BUFFER_MMAP)
	393	return -EINVAL;
	394	mmap_buf_len = chan->backend.buf_size;
	395	if (chan->backend.extra_reader_sb)
	396	mmap_buf_len += chan->backend.subbuf_size;
	397	if (mmap_buf_len > UINT_MAX)
	398	return -EFBIG;
4343ec8e	399	return compat_put_ulong(mmap_buf_len, arg);
f3bc08c5	400	}
216f7feb	401	case RING_BUFFER_COMPAT_GET_MMAP_READ_OFFSET:
f3bc08c5 MD	402	{
	403	unsigned long sb_bindex, read_offset;
	404
	405	if (config->output != RING_BUFFER_MMAP)
	406	return -EINVAL;
	407	sb_bindex = subbuffer_id_get_index(config,
	408	buf->backend.buf_rsb.id);
	409	read_offset = buf->backend.array[sb_bindex]->mmap_offset;
	410	if (read_offset > UINT_MAX)
	411	return -EINVAL;
4343ec8e	412	return compat_put_ulong(read_offset, arg);
f3bc08c5	413	}
216f7feb	414	case RING_BUFFER_COMPAT_FLUSH:
5e391252	415	lib_ring_buffer_switch_remote(buf);
5c055266	416	return 0;
c6f05468 MD	417	case RING_BUFFER_COMPAT_FLUSH_EMPTY:
	418	lib_ring_buffer_switch_remote_empty(buf);
	419	return 0;
c245d0d3 MD	420	case RING_BUFFER_COMPAT_CLEAR:
	421	lib_ring_buffer_clear(buf);
	422	return 0;
f3bc08c5 MD	423	default:
	424	return -ENOIOCTLCMD;
	425	}
	426	}
d83004aa JD	427	EXPORT_SYMBOL_GPL(lib_ring_buffer_compat_ioctl);
	428
	429	static
	430	long vfs_lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd,
	431	unsigned long arg)
	432	{
	433	struct lib_ring_buffer *buf = filp->private_data;
	434
	435	return lib_ring_buffer_compat_ioctl(filp, cmd, arg, buf);
	436	}
f3bc08c5 MD	437	#endif
	438
	439	const struct file_operations lib_ring_buffer_file_operations = {
a33c9927	440	.owner = THIS_MODULE,
d83004aa JD	441	.open = vfs_lib_ring_buffer_open,
	442	.release = vfs_lib_ring_buffer_release,
	443	.poll = vfs_lib_ring_buffer_poll,
	444	.splice_read = vfs_lib_ring_buffer_splice_read,
	445	.mmap = vfs_lib_ring_buffer_mmap,
	446	.unlocked_ioctl = vfs_lib_ring_buffer_ioctl,
	447	.llseek = vfs_lib_ring_buffer_no_llseek,
f3bc08c5	448	#ifdef CONFIG_COMPAT
d83004aa	449	.compat_ioctl = vfs_lib_ring_buffer_compat_ioctl,
f3bc08c5 MD	450	#endif
	451	};
	452	EXPORT_SYMBOL_GPL(lib_ring_buffer_file_operations);
	453
	454	MODULE_LICENSE("GPL and additional rights");
1c124020 MJ	455	MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
1c124020 MJ	456	MODULE_DESCRIPTION("LTTng ring buffer library");
13ab8b0a MD	457	MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
	458	__stringify(LTTNG_MODULES_MINOR_VERSION) "."
	459	__stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
	460	LTTNG_MODULES_EXTRAVERSION);