Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1102 insertions, 0 deletions

diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c
new file mode 100644
index 000000000..f2593133e
--- /dev/null
+++ b/drivers/input/misc/uinput.c
@@ -0,0 +1,1102 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  User level driver support for input subsystem
+ *
+ * Heavily based on evdev.c by Vojtech Pavlik
+ *
+ * Author: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
+ *
+ * Changes/Revisions:
+ *	0.4	01/09/2014 (Benjamin Tissoires <benjamin.tissoires@redhat.com>)
+ *		- add UI_GET_SYSNAME ioctl
+ *	0.3	09/04/2006 (Anssi Hannula <anssi.hannula@gmail.com>)
+ *		- updated ff support for the changes in kernel interface
+ *		- added MODULE_VERSION
+ *	0.2	16/10/2004 (Micah Dowty <micah@navi.cx>)
+ *		- added force feedback support
+ *              - added UI_SET_PHYS
+ *	0.1	20/06/2002
+ *		- first public version
+ */
+#include <uapi/linux/uinput.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/overflow.h>
+#include <linux/input/mt.h>
+#include "../input-compat.h"
+
+#define UINPUT_NAME		"uinput"
+#define UINPUT_BUFFER_SIZE	16
+#define UINPUT_NUM_REQUESTS	16
+
+enum uinput_state { UIST_NEW_DEVICE, UIST_SETUP_COMPLETE, UIST_CREATED };
+
+struct uinput_request {
+	unsigned int		id;
+	unsigned int		code;	/* UI_FF_UPLOAD, UI_FF_ERASE */
+
+	int			retval;
+	struct completion	done;
+
+	union {
+		unsigned int	effect_id;
+		struct {
+			struct ff_effect *effect;
+			struct ff_effect *old;
+		} upload;
+	} u;
+};
+
+struct uinput_device {
+	struct input_dev	*dev;
+	struct mutex		mutex;
+	enum uinput_state	state;
+	wait_queue_head_t	waitq;
+	unsigned char		ready;
+	unsigned char		head;
+	unsigned char		tail;
+	struct input_event	buff[UINPUT_BUFFER_SIZE];
+	unsigned int		ff_effects_max;
+
+	struct uinput_request	*requests[UINPUT_NUM_REQUESTS];
+	wait_queue_head_t	requests_waitq;
+	spinlock_t		requests_lock;
+};
+
+static int uinput_dev_event(struct input_dev *dev,
+			    unsigned int type, unsigned int code, int value)
+{
+	struct uinput_device	*udev = input_get_drvdata(dev);
+	struct timespec64	ts;
+
+	ktime_get_ts64(&ts);
+
+	udev->buff[udev->head] = (struct input_event) {
+		.input_event_sec = ts.tv_sec,
+		.input_event_usec = ts.tv_nsec / NSEC_PER_USEC,
+		.type = type,
+		.code = code,
+		.value = value,
+	};
+
+	udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE;
+
+	wake_up_interruptible(&udev->waitq);
+
+	return 0;
+}
+
+/* Atomically allocate an ID for the given request. Returns 0 on success. */
+static bool uinput_request_alloc_id(struct uinput_device *udev,
+				    struct uinput_request *request)
+{
+	unsigned int id;
+	bool reserved = false;
+
+	spin_lock(&udev->requests_lock);
+
+	for (id = 0; id < UINPUT_NUM_REQUESTS; id++) {
+		if (!udev->requests[id]) {
+			request->id = id;
+			udev->requests[id] = request;
+			reserved = true;
+			break;
+		}
+	}
+
+	spin_unlock(&udev->requests_lock);
+	return reserved;
+}
+
+static struct uinput_request *uinput_request_find(struct uinput_device *udev,
+						  unsigned int id)
+{
+	/* Find an input request, by ID. Returns NULL if the ID isn't valid. */
+	if (id >= UINPUT_NUM_REQUESTS)
+		return NULL;
+
+	return udev->requests[id];
+}
+
+static int uinput_request_reserve_slot(struct uinput_device *udev,
+				       struct uinput_request *request)
+{
+	/* Allocate slot. If none are available right away, wait. */
+	return wait_event_interruptible(udev->requests_waitq,
+					uinput_request_alloc_id(udev, request));
+}
+
+static void uinput_request_release_slot(struct uinput_device *udev,
+					unsigned int id)
+{
+	/* Mark slot as available */
+	spin_lock(&udev->requests_lock);
+	udev->requests[id] = NULL;
+	spin_unlock(&udev->requests_lock);
+
+	wake_up(&udev->requests_waitq);
+}
+
+static int uinput_request_send(struct uinput_device *udev,
+			       struct uinput_request *request)
+{
+	int retval;
+
+	retval = mutex_lock_interruptible(&udev->mutex);
+	if (retval)
+		return retval;
+
+	if (udev->state != UIST_CREATED) {
+		retval = -ENODEV;
+		goto out;
+	}
+
+	init_completion(&request->done);
+
+	/*
+	 * Tell our userspace application about this new request
+	 * by queueing an input event.
+	 */
+	uinput_dev_event(udev->dev, EV_UINPUT, request->code, request->id);
+
+ out:
+	mutex_unlock(&udev->mutex);
+	return retval;
+}
+
+static int uinput_request_submit(struct uinput_device *udev,
+				 struct uinput_request *request)
+{
+	int retval;
+
+	retval = uinput_request_reserve_slot(udev, request);
+	if (retval)
+		return retval;
+
+	retval = uinput_request_send(udev, request);
+	if (retval)
+		goto out;
+
+	if (!wait_for_completion_timeout(&request->done, 30 * HZ)) {
+		retval = -ETIMEDOUT;
+		goto out;
+	}
+
+	retval = request->retval;
+
+ out:
+	uinput_request_release_slot(udev, request->id);
+	return retval;
+}
+
+/*
+ * Fail all outstanding requests so handlers don't wait for the userspace
+ * to finish processing them.
+ */
+static void uinput_flush_requests(struct uinput_device *udev)
+{
+	struct uinput_request *request;
+	int i;
+
+	spin_lock(&udev->requests_lock);
+
+	for (i = 0; i < UINPUT_NUM_REQUESTS; i++) {
+		request = udev->requests[i];
+		if (request) {
+			request->retval = -ENODEV;
+			complete(&request->done);
+		}
+	}
+
+	spin_unlock(&udev->requests_lock);
+}
+
+static void uinput_dev_set_gain(struct input_dev *dev, u16 gain)
+{
+	uinput_dev_event(dev, EV_FF, FF_GAIN, gain);
+}
+
+static void uinput_dev_set_autocenter(struct input_dev *dev, u16 magnitude)
+{
+	uinput_dev_event(dev, EV_FF, FF_AUTOCENTER, magnitude);
+}
+
+static int uinput_dev_playback(struct input_dev *dev, int effect_id, int value)
+{
+	return uinput_dev_event(dev, EV_FF, effect_id, value);
+}
+
+static int uinput_dev_upload_effect(struct input_dev *dev,
+				    struct ff_effect *effect,
+				    struct ff_effect *old)
+{
+	struct uinput_device *udev = input_get_drvdata(dev);
+	struct uinput_request request;
+
+	/*
+	 * uinput driver does not currently support periodic effects with
+	 * custom waveform since it does not have a way to pass buffer of
+	 * samples (custom_data) to userspace. If ever there is a device
+	 * supporting custom waveforms we would need to define an additional
+	 * ioctl (UI_UPLOAD_SAMPLES) but for now we just bail out.
+	 */
+	if (effect->type == FF_PERIODIC &&
+			effect->u.periodic.waveform == FF_CUSTOM)
+		return -EINVAL;
+
+	request.code = UI_FF_UPLOAD;
+	request.u.upload.effect = effect;
+	request.u.upload.old = old;
+
+	return uinput_request_submit(udev, &request);
+}
+
+static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id)
+{
+	struct uinput_device *udev = input_get_drvdata(dev);
+	struct uinput_request request;
+
+	if (!test_bit(EV_FF, dev->evbit))
+		return -ENOSYS;
+
+	request.code = UI_FF_ERASE;
+	request.u.effect_id = effect_id;
+
+	return uinput_request_submit(udev, &request);
+}
+
+static int uinput_dev_flush(struct input_dev *dev, struct file *file)
+{
+	/*
+	 * If we are called with file == NULL that means we are tearing
+	 * down the device, and therefore we can not handle FF erase
+	 * requests: either we are handling UI_DEV_DESTROY (and holding
+	 * the udev->mutex), or the file descriptor is closed and there is
+	 * nobody on the other side anymore.
+	 */
+	return file ? input_ff_flush(dev, file) : 0;
+}
+
+static void uinput_destroy_device(struct uinput_device *udev)
+{
+	const char *name, *phys;
+	struct input_dev *dev = udev->dev;
+	enum uinput_state old_state = udev->state;
+
+	udev->state = UIST_NEW_DEVICE;
+
+	if (dev) {
+		name = dev->name;
+		phys = dev->phys;
+		if (old_state == UIST_CREATED) {
+			uinput_flush_requests(udev);
+			input_unregister_device(dev);
+		} else {
+			input_free_device(dev);
+		}
+		kfree(name);
+		kfree(phys);
+		udev->dev = NULL;
+	}
+}
+
+static int uinput_create_device(struct uinput_device *udev)
+{
+	struct input_dev *dev = udev->dev;
+	int error, nslot;
+
+	if (udev->state != UIST_SETUP_COMPLETE) {
+		printk(KERN_DEBUG "%s: write device info first\n", UINPUT_NAME);
+		return -EINVAL;
+	}
+
+	if (test_bit(EV_ABS, dev->evbit)) {
+		input_alloc_absinfo(dev);
+		if (!dev->absinfo) {
+			error = -EINVAL;
+			goto fail1;
+		}
+
+		if (test_bit(ABS_MT_SLOT, dev->absbit)) {
+			nslot = input_abs_get_max(dev, ABS_MT_SLOT) + 1;
+			error = input_mt_init_slots(dev, nslot, 0);
+			if (error)
+				goto fail1;
+		} else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
+			input_set_events_per_packet(dev, 60);
+		}
+	}
+
+	if (test_bit(EV_FF, dev->evbit) && !udev->ff_effects_max) {
+		printk(KERN_DEBUG "%s: ff_effects_max should be non-zero when FF_BIT is set\n",
+			UINPUT_NAME);
+		error = -EINVAL;
+		goto fail1;
+	}
+
+	if (udev->ff_effects_max) {
+		error = input_ff_create(dev, udev->ff_effects_max);
+		if (error)
+			goto fail1;
+
+		dev->ff->upload = uinput_dev_upload_effect;
+		dev->ff->erase = uinput_dev_erase_effect;
+		dev->ff->playback = uinput_dev_playback;
+		dev->ff->set_gain = uinput_dev_set_gain;
+		dev->ff->set_autocenter = uinput_dev_set_autocenter;
+		/*
+		 * The standard input_ff_flush() implementation does
+		 * not quite work for uinput as we can't reasonably
+		 * handle FF requests during device teardown.
+		 */
+		dev->flush = uinput_dev_flush;
+	}
+
+	dev->event = uinput_dev_event;
+
+	input_set_drvdata(udev->dev, udev);
+
+	error = input_register_device(udev->dev);
+	if (error)
+		goto fail2;
+
+	udev->state = UIST_CREATED;
+
+	return 0;
+
+ fail2:	input_ff_destroy(dev);
+ fail1: uinput_destroy_device(udev);
+	return error;
+}
+
+static int uinput_open(struct inode *inode, struct file *file)
+{
+	struct uinput_device *newdev;
+
+	newdev = kzalloc(sizeof(struct uinput_device), GFP_KERNEL);
+	if (!newdev)
+		return -ENOMEM;
+
+	mutex_init(&newdev->mutex);
+	spin_lock_init(&newdev->requests_lock);
+	init_waitqueue_head(&newdev->requests_waitq);
+	init_waitqueue_head(&newdev->waitq);
+	newdev->state = UIST_NEW_DEVICE;
+
+	file->private_data = newdev;
+	stream_open(inode, file);
+
+	return 0;
+}
+
+static int uinput_validate_absinfo(struct input_dev *dev, unsigned int code,
+				   const struct input_absinfo *abs)
+{
+	int min, max, range;
+
+	min = abs->minimum;
+	max = abs->maximum;
+
+	if ((min != 0 || max != 0) && max < min) {
+		printk(KERN_DEBUG
+		       "%s: invalid abs[%02x] min:%d max:%d\n",
+		       UINPUT_NAME, code, min, max);
+		return -EINVAL;
+	}
+
+	if (!check_sub_overflow(max, min, &range) && abs->flat > range) {
+		printk(KERN_DEBUG
+		       "%s: abs_flat #%02x out of range: %d (min:%d/max:%d)\n",
+		       UINPUT_NAME, code, abs->flat, min, max);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int uinput_validate_absbits(struct input_dev *dev)
+{
+	unsigned int cnt;
+	int error;
+
+	if (!test_bit(EV_ABS, dev->evbit))
+		return 0;
+
+	/*
+	 * Check if absmin/absmax/absfuzz/absflat are sane.
+	 */
+
+	for_each_set_bit(cnt, dev->absbit, ABS_CNT) {
+		if (!dev->absinfo)
+			return -EINVAL;
+
+		error = uinput_validate_absinfo(dev, cnt, &dev->absinfo[cnt]);
+		if (error)
+			return error;
+	}
+
+	return 0;
+}
+
+static int uinput_dev_setup(struct uinput_device *udev,
+			    struct uinput_setup __user *arg)
+{
+	struct uinput_setup setup;
+	struct input_dev *dev;
+
+	if (udev->state == UIST_CREATED)
+		return -EINVAL;
+
+	if (copy_from_user(&setup, arg, sizeof(setup)))
+		return -EFAULT;
+
+	if (!setup.name[0])
+		return -EINVAL;
+
+	dev = udev->dev;
+	dev->id = setup.id;
+	udev->ff_effects_max = setup.ff_effects_max;
+
+	kfree(dev->name);
+	dev->name = kstrndup(setup.name, UINPUT_MAX_NAME_SIZE, GFP_KERNEL);
+	if (!dev->name)
+		return -ENOMEM;
+
+	udev->state = UIST_SETUP_COMPLETE;
+	return 0;
+}
+
+static int uinput_abs_setup(struct uinput_device *udev,
+			    struct uinput_setup __user *arg, size_t size)
+{
+	struct uinput_abs_setup setup = {};
+	struct input_dev *dev;
+	int error;
+
+	if (size > sizeof(setup))
+		return -E2BIG;
+
+	if (udev->state == UIST_CREATED)
+		return -EINVAL;
+
+	if (copy_from_user(&setup, arg, size))
+		return -EFAULT;
+
+	if (setup.code > ABS_MAX)
+		return -ERANGE;
+
+	dev = udev->dev;
+
+	error = uinput_validate_absinfo(dev, setup.code, &setup.absinfo);
+	if (error)
+		return error;
+
+	input_alloc_absinfo(dev);
+	if (!dev->absinfo)
+		return -ENOMEM;
+
+	set_bit(setup.code, dev->absbit);
+	dev->absinfo[setup.code] = setup.absinfo;
+	return 0;
+}
+
+/* legacy setup via write() */
+static int uinput_setup_device_legacy(struct uinput_device *udev,
+				      const char __user *buffer, size_t count)
+{
+	struct uinput_user_dev	*user_dev;
+	struct input_dev	*dev;
+	int			i;
+	int			retval;
+
+	if (count != sizeof(struct uinput_user_dev))
+		return -EINVAL;
+
+	if (!udev->dev) {
+		udev->dev = input_allocate_device();
+		if (!udev->dev)
+			return -ENOMEM;
+	}
+
+	dev = udev->dev;
+
+	user_dev = memdup_user(buffer, sizeof(struct uinput_user_dev));
+	if (IS_ERR(user_dev))
+		return PTR_ERR(user_dev);
+
+	udev->ff_effects_max = user_dev->ff_effects_max;
+
+	/* Ensure name is filled in */
+	if (!user_dev->name[0]) {
+		retval = -EINVAL;
+		goto exit;
+	}
+
+	kfree(dev->name);
+	dev->name = kstrndup(user_dev->name, UINPUT_MAX_NAME_SIZE,
+			     GFP_KERNEL);
+	if (!dev->name) {
+		retval = -ENOMEM;
+		goto exit;
+	}
+
+	dev->id.bustype	= user_dev->id.bustype;
+	dev->id.vendor	= user_dev->id.vendor;
+	dev->id.product	= user_dev->id.product;
+	dev->id.version	= user_dev->id.version;
+
+	for (i = 0; i < ABS_CNT; i++) {
+		input_abs_set_max(dev, i, user_dev->absmax[i]);
+		input_abs_set_min(dev, i, user_dev->absmin[i]);
+		input_abs_set_fuzz(dev, i, user_dev->absfuzz[i]);
+		input_abs_set_flat(dev, i, user_dev->absflat[i]);
+	}
+
+	retval = uinput_validate_absbits(dev);
+	if (retval < 0)
+		goto exit;
+
+	udev->state = UIST_SETUP_COMPLETE;
+	retval = count;
+
+ exit:
+	kfree(user_dev);
+	return retval;
+}
+
+static ssize_t uinput_inject_events(struct uinput_device *udev,
+				    const char __user *buffer, size_t count)
+{
+	struct input_event ev;
+	size_t bytes = 0;
+
+	if (count != 0 && count < input_event_size())
+		return -EINVAL;
+
+	while (bytes + input_event_size() <= count) {
+		/*
+		 * Note that even if some events were fetched successfully
+		 * we are still going to return EFAULT instead of partial
+		 * count to let userspace know that it got it's buffers
+		 * all wrong.
+		 */
+		if (input_event_from_user(buffer + bytes, &ev))
+			return -EFAULT;
+
+		input_event(udev->dev, ev.type, ev.code, ev.value);
+		bytes += input_event_size();
+		cond_resched();
+	}
+
+	return bytes;
+}
+
+static ssize_t uinput_write(struct file *file, const char __user *buffer,
+			    size_t count, loff_t *ppos)
+{
+	struct uinput_device *udev = file->private_data;
+	int retval;
+
+	if (count == 0)
+		return 0;
+
+	retval = mutex_lock_interruptible(&udev->mutex);
+	if (retval)
+		return retval;
+
+	retval = udev->state == UIST_CREATED ?
+			uinput_inject_events(udev, buffer, count) :
+			uinput_setup_device_legacy(udev, buffer, count);
+
+	mutex_unlock(&udev->mutex);
+
+	return retval;
+}
+
+static bool uinput_fetch_next_event(struct uinput_device *udev,
+				    struct input_event *event)
+{
+	bool have_event;
+
+	spin_lock_irq(&udev->dev->event_lock);
+
+	have_event = udev->head != udev->tail;
+	if (have_event) {
+		*event = udev->buff[udev->tail];
+		udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
+	}
+
+	spin_unlock_irq(&udev->dev->event_lock);
+
+	return have_event;
+}
+
+static ssize_t uinput_events_to_user(struct uinput_device *udev,
+				     char __user *buffer, size_t count)
+{
+	struct input_event event;
+	size_t read = 0;
+
+	while (read + input_event_size() <= count &&
+	       uinput_fetch_next_event(udev, &event)) {
+
+		if (input_event_to_user(buffer + read, &event))
+			return -EFAULT;
+
+		read += input_event_size();
+	}
+
+	return read;
+}
+
+static ssize_t uinput_read(struct file *file, char __user *buffer,
+			   size_t count, loff_t *ppos)
+{
+	struct uinput_device *udev = file->private_data;
+	ssize_t retval;
+
+	if (count != 0 && count < input_event_size())
+		return -EINVAL;
+
+	do {
+		retval = mutex_lock_interruptible(&udev->mutex);
+		if (retval)
+			return retval;
+
+		if (udev->state != UIST_CREATED)
+			retval = -ENODEV;
+		else if (udev->head == udev->tail &&
+			 (file->f_flags & O_NONBLOCK))
+			retval = -EAGAIN;
+		else
+			retval = uinput_events_to_user(udev, buffer, count);
+
+		mutex_unlock(&udev->mutex);
+
+		if (retval || count == 0)
+			break;
+
+		if (!(file->f_flags & O_NONBLOCK))
+			retval = wait_event_interruptible(udev->waitq,
+						  udev->head != udev->tail ||
+						  udev->state != UIST_CREATED);
+	} while (retval == 0);
+
+	return retval;
+}
+
+static __poll_t uinput_poll(struct file *file, poll_table *wait)
+{
+	struct uinput_device *udev = file->private_data;
+	__poll_t mask = EPOLLOUT | EPOLLWRNORM; /* uinput is always writable */
+
+	poll_wait(file, &udev->waitq, wait);
+
+	if (udev->head != udev->tail)
+		mask |= EPOLLIN | EPOLLRDNORM;
+
+	return mask;
+}
+
+static int uinput_release(struct inode *inode, struct file *file)
+{
+	struct uinput_device *udev = file->private_data;
+
+	uinput_destroy_device(udev);
+	kfree(udev);
+
+	return 0;
+}
+
+#ifdef CONFIG_COMPAT
+struct uinput_ff_upload_compat {
+	__u32			request_id;
+	__s32			retval;
+	struct ff_effect_compat	effect;
+	struct ff_effect_compat	old;
+};
+
+static int uinput_ff_upload_to_user(char __user *buffer,
+				    const struct uinput_ff_upload *ff_up)
+{
+	if (in_compat_syscall()) {
+		struct uinput_ff_upload_compat ff_up_compat;
+
+		ff_up_compat.request_id = ff_up->request_id;
+		ff_up_compat.retval = ff_up->retval;
+		/*
+		 * It so happens that the pointer that gives us the trouble
+		 * is the last field in the structure. Since we don't support
+		 * custom waveforms in uinput anyway we can just copy the whole
+		 * thing (to the compat size) and ignore the pointer.
+		 */
+		memcpy(&ff_up_compat.effect, &ff_up->effect,
+			sizeof(struct ff_effect_compat));
+		memcpy(&ff_up_compat.old, &ff_up->old,
+			sizeof(struct ff_effect_compat));
+
+		if (copy_to_user(buffer, &ff_up_compat,
+				 sizeof(struct uinput_ff_upload_compat)))
+			return -EFAULT;
+	} else {
+		if (copy_to_user(buffer, ff_up,
+				 sizeof(struct uinput_ff_upload)))
+			return -EFAULT;
+	}
+
+	return 0;
+}
+
+static int uinput_ff_upload_from_user(const char __user *buffer,
+				      struct uinput_ff_upload *ff_up)
+{
+	if (in_compat_syscall()) {
+		struct uinput_ff_upload_compat ff_up_compat;
+
+		if (copy_from_user(&ff_up_compat, buffer,
+				   sizeof(struct uinput_ff_upload_compat)))
+			return -EFAULT;
+
+		ff_up->request_id = ff_up_compat.request_id;
+		ff_up->retval = ff_up_compat.retval;
+		memcpy(&ff_up->effect, &ff_up_compat.effect,
+			sizeof(struct ff_effect_compat));
+		memcpy(&ff_up->old, &ff_up_compat.old,
+			sizeof(struct ff_effect_compat));
+
+	} else {
+		if (copy_from_user(ff_up, buffer,
+				   sizeof(struct uinput_ff_upload)))
+			return -EFAULT;
+	}
+
+	return 0;
+}
+
+#else
+
+static int uinput_ff_upload_to_user(char __user *buffer,
+				    const struct uinput_ff_upload *ff_up)
+{
+	if (copy_to_user(buffer, ff_up, sizeof(struct uinput_ff_upload)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int uinput_ff_upload_from_user(const char __user *buffer,
+				      struct uinput_ff_upload *ff_up)
+{
+	if (copy_from_user(ff_up, buffer, sizeof(struct uinput_ff_upload)))
+		return -EFAULT;
+
+	return 0;
+}
+
+#endif
+
+#define uinput_set_bit(_arg, _bit, _max)		\
+({							\
+	int __ret = 0;					\
+	if (udev->state == UIST_CREATED)		\
+		__ret =  -EINVAL;			\
+	else if ((_arg) > (_max))			\
+		__ret = -EINVAL;			\
+	else set_bit((_arg), udev->dev->_bit);		\
+	__ret;						\
+})
+
+static int uinput_str_to_user(void __user *dest, const char *str,
+			      unsigned int maxlen)
+{
+	char __user *p = dest;
+	int len, ret;
+
+	if (!str)
+		return -ENOENT;
+
+	if (maxlen == 0)
+		return -EINVAL;
+
+	len = strlen(str) + 1;
+	if (len > maxlen)
+		len = maxlen;
+
+	ret = copy_to_user(p, str, len);
+	if (ret)
+		return -EFAULT;
+
+	/* force terminating '\0' */
+	ret = put_user(0, p + len - 1);
+	return ret ? -EFAULT : len;
+}
+
+static long uinput_ioctl_handler(struct file *file, unsigned int cmd,
+				 unsigned long arg, void __user *p)
+{
+	int			retval;
+	struct uinput_device	*udev = file->private_data;
+	struct uinput_ff_upload ff_up;
+	struct uinput_ff_erase  ff_erase;
+	struct uinput_request   *req;
+	char			*phys;
+	const char		*name;
+	unsigned int		size;
+
+	retval = mutex_lock_interruptible(&udev->mutex);
+	if (retval)
+		return retval;
+
+	if (!udev->dev) {
+		udev->dev = input_allocate_device();
+		if (!udev->dev) {
+			retval = -ENOMEM;
+			goto out;
+		}
+	}
+
+	switch (cmd) {
+	case UI_GET_VERSION:
+		if (put_user(UINPUT_VERSION, (unsigned int __user *)p))
+			retval = -EFAULT;
+		goto out;
+
+	case UI_DEV_CREATE:
+		retval = uinput_create_device(udev);
+		goto out;
+
+	case UI_DEV_DESTROY:
+		uinput_destroy_device(udev);
+		goto out;
+
+	case UI_DEV_SETUP:
+		retval = uinput_dev_setup(udev, p);
+		goto out;
+
+	/* UI_ABS_SETUP is handled in the variable size ioctls */
+
+	case UI_SET_EVBIT:
+		retval = uinput_set_bit(arg, evbit, EV_MAX);
+		goto out;
+
+	case UI_SET_KEYBIT:
+		retval = uinput_set_bit(arg, keybit, KEY_MAX);
+		goto out;
+
+	case UI_SET_RELBIT:
+		retval = uinput_set_bit(arg, relbit, REL_MAX);
+		goto out;
+
+	case UI_SET_ABSBIT:
+		retval = uinput_set_bit(arg, absbit, ABS_MAX);
+		goto out;
+
+	case UI_SET_MSCBIT:
+		retval = uinput_set_bit(arg, mscbit, MSC_MAX);
+		goto out;
+
+	case UI_SET_LEDBIT:
+		retval = uinput_set_bit(arg, ledbit, LED_MAX);
+		goto out;
+
+	case UI_SET_SNDBIT:
+		retval = uinput_set_bit(arg, sndbit, SND_MAX);
+		goto out;
+
+	case UI_SET_FFBIT:
+		retval = uinput_set_bit(arg, ffbit, FF_MAX);
+		goto out;
+
+	case UI_SET_SWBIT:
+		retval = uinput_set_bit(arg, swbit, SW_MAX);
+		goto out;
+
+	case UI_SET_PROPBIT:
+		retval = uinput_set_bit(arg, propbit, INPUT_PROP_MAX);
+		goto out;
+
+	case UI_SET_PHYS:
+		if (udev->state == UIST_CREATED) {
+			retval = -EINVAL;
+			goto out;
+		}
+
+		phys = strndup_user(p, 1024);
+		if (IS_ERR(phys)) {
+			retval = PTR_ERR(phys);
+			goto out;
+		}
+
+		kfree(udev->dev->phys);
+		udev->dev->phys = phys;
+		goto out;
+
+	case UI_BEGIN_FF_UPLOAD:
+		retval = uinput_ff_upload_from_user(p, &ff_up);
+		if (retval)
+			goto out;
+
+		req = uinput_request_find(udev, ff_up.request_id);
+		if (!req || req->code != UI_FF_UPLOAD ||
+		    !req->u.upload.effect) {
+			retval = -EINVAL;
+			goto out;
+		}
+
+		ff_up.retval = 0;
+		ff_up.effect = *req->u.upload.effect;
+		if (req->u.upload.old)
+			ff_up.old = *req->u.upload.old;
+		else
+			memset(&ff_up.old, 0, sizeof(struct ff_effect));
+
+		retval = uinput_ff_upload_to_user(p, &ff_up);
+		goto out;
+
+	case UI_BEGIN_FF_ERASE:
+		if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
+			retval = -EFAULT;
+			goto out;
+		}
+
+		req = uinput_request_find(udev, ff_erase.request_id);
+		if (!req || req->code != UI_FF_ERASE) {
+			retval = -EINVAL;
+			goto out;
+		}
+
+		ff_erase.retval = 0;
+		ff_erase.effect_id = req->u.effect_id;
+		if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
+			retval = -EFAULT;
+			goto out;
+		}
+
+		goto out;
+
+	case UI_END_FF_UPLOAD:
+		retval = uinput_ff_upload_from_user(p, &ff_up);
+		if (retval)
+			goto out;
+
+		req = uinput_request_find(udev, ff_up.request_id);
+		if (!req || req->code != UI_FF_UPLOAD ||
+		    !req->u.upload.effect) {
+			retval = -EINVAL;
+			goto out;
+		}
+
+		req->retval = ff_up.retval;
+		complete(&req->done);
+		goto out;
+
+	case UI_END_FF_ERASE:
+		if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
+			retval = -EFAULT;
+			goto out;
+		}
+
+		req = uinput_request_find(udev, ff_erase.request_id);
+		if (!req || req->code != UI_FF_ERASE) {
+			retval = -EINVAL;
+			goto out;
+		}
+
+		req->retval = ff_erase.retval;
+		complete(&req->done);
+		goto out;
+	}
+
+	size = _IOC_SIZE(cmd);
+
+	/* Now check variable-length commands */
+	switch (cmd & ~IOCSIZE_MASK) {
+	case UI_GET_SYSNAME(0):
+		if (udev->state != UIST_CREATED) {
+			retval = -ENOENT;
+			goto out;
+		}
+		name = dev_name(&udev->dev->dev);
+		retval = uinput_str_to_user(p, name, size);
+		goto out;
+
+	case UI_ABS_SETUP & ~IOCSIZE_MASK:
+		retval = uinput_abs_setup(udev, p, size);
+		goto out;
+	}
+
+	retval = -EINVAL;
+ out:
+	mutex_unlock(&udev->mutex);
+	return retval;
+}
+
+static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	return uinput_ioctl_handler(file, cmd, arg, (void __user *)arg);
+}
+
+#ifdef CONFIG_COMPAT
+
+/*
+ * These IOCTLs change their size and thus their numbers between
+ * 32 and 64 bits.
+ */
+#define UI_SET_PHYS_COMPAT		\
+	_IOW(UINPUT_IOCTL_BASE, 108, compat_uptr_t)
+#define UI_BEGIN_FF_UPLOAD_COMPAT	\
+	_IOWR(UINPUT_IOCTL_BASE, 200, struct uinput_ff_upload_compat)
+#define UI_END_FF_UPLOAD_COMPAT		\
+	_IOW(UINPUT_IOCTL_BASE, 201, struct uinput_ff_upload_compat)
+
+static long uinput_compat_ioctl(struct file *file,
+				unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case UI_SET_PHYS_COMPAT:
+		cmd = UI_SET_PHYS;
+		break;
+	case UI_BEGIN_FF_UPLOAD_COMPAT:
+		cmd = UI_BEGIN_FF_UPLOAD;
+		break;
+	case UI_END_FF_UPLOAD_COMPAT:
+		cmd = UI_END_FF_UPLOAD;
+		break;
+	}
+
+	return uinput_ioctl_handler(file, cmd, arg, compat_ptr(arg));
+}
+#endif
+
+static const struct file_operations uinput_fops = {
+	.owner		= THIS_MODULE,
+	.open		= uinput_open,
+	.release	= uinput_release,
+	.read		= uinput_read,
+	.write		= uinput_write,
+	.poll		= uinput_poll,
+	.unlocked_ioctl	= uinput_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= uinput_compat_ioctl,
+#endif
+	.llseek		= no_llseek,
+};
+
+static struct miscdevice uinput_misc = {
+	.fops		= &uinput_fops,
+	.minor		= UINPUT_MINOR,
+	.name		= UINPUT_NAME,
+};
+module_misc_device(uinput_misc);
+
+MODULE_ALIAS_MISCDEV(UINPUT_MINOR);
+MODULE_ALIAS("devname:" UINPUT_NAME);
+
+MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
+MODULE_DESCRIPTION("User level driver support for input subsystem");
+MODULE_LICENSE("GPL");