Release 4.11 drivers/input/misc/uinput.c

/*
 *  User level driver support for input subsystem
 *
 * Heavily based on evdev.c by Vojtech Pavlik
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * 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 <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/uinput.h>
#include <linux/input/mt.h>
#include "../input-compat.h"



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);

	udev->buff[udev->head].type = type;
	udev->buff[udev->head].code = code;
	udev->buff[udev->head].value = value;
	do_gettimeofday(&udev->buff[udev->head].time);
	udev->head = (udev->head + 1) % UINPUT_BUFFER_SIZE;

	wake_up_interruptible(&udev->waitq);

	return 0;
}

Contributors
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Vojtech Pavlik
92
82.88%
1
33.33%
Neil Brown
14
12.61%
1
33.33%
Dmitry Torokhov
5
4.50%
1
33.33%
Total
111
100.00%
3
100.00%

/* 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;
}

Contributors
Person
Tokens
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CommitProp
Micah Dowty
35
38.46%
1
12.50%
Vojtech Pavlik
26
28.57%
1
12.50%
Dmitry Torokhov
25
27.47%
4
50.00%
Zach Welch
3
3.30%
1
12.50%
Aristeu Sergio Rozanski Filho
2
2.20%
1
12.50%
Total
91
100.00%
8
100.00%



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];
}

Contributors
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Micah Dowty
19
54.29%
1
33.33%
Vojtech Pavlik
15
42.86%
1
33.33%
Dmitry Torokhov
1
2.86%
1
33.33%
Total
35
100.00%
3
100.00%



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));
}

Contributors
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Dmitry Torokhov
15
46.88%
1
33.33%
Vojtech Pavlik
12
37.50%
1
33.33%
Micah Dowty
5
15.62%
1
33.33%
Total
32
100.00%
3
100.00%



static void uinput_request_done(struct uinput_device *udev,
				struct uinput_request *request)
{
	/* Mark slot as available */
	udev->requests[request->id] = NULL;
	wake_up(&udev->requests_waitq);

	complete(&request->done);
}

Contributors
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Dmitry Torokhov
33
75.00%
3
60.00%
Micah Dowty
7
15.91%
1
20.00%
Vojtech Pavlik
4
9.09%
1
20.00%
Total
44
100.00%
5
100.00%



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;
}

Contributors
Person
Tokens
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CommitProp
Aristeu Sergio Rozanski Filho
50
53.76%
1
16.67%
Micah Dowty
24
25.81%
1
16.67%
Dmitry Torokhov
13
13.98%
3
50.00%
Vojtech Pavlik
6
6.45%
1
16.67%
Total
93
100.00%
6
100.00%



static int uinput_request_submit(struct uinput_device *udev,
				 struct uinput_request *request)
{
	int error;

	error = uinput_request_reserve_slot(udev, request);
	if (error)
		return error;

	error = uinput_request_send(udev, request);
	if (error) {
		uinput_request_done(udev, request);
		return error;
	}

	wait_for_completion(&request->done);
	return request->retval;
}

Contributors
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Dmitry Torokhov
73
100.00%
1
100.00%
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73
100.00%
1
100.00%

/*
 * 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;
			uinput_request_done(udev, request);
		}
	}

	spin_unlock(&udev->requests_lock);
}

Contributors
Person
Tokens
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Commits
CommitProp
Aristeu Sergio Rozanski Filho
75
94.94%
1
25.00%
Micah Dowty
2
2.53%
1
25.00%
Dmitry Torokhov
1
1.27%
1
25.00%
Vojtech Pavlik
1
1.27%
1
25.00%
Total
79
100.00%
4
100.00%



static void uinput_dev_set_gain(struct input_dev *dev, u16 gain)
{
	uinput_dev_event(dev, EV_FF, FF_GAIN, gain);
}

Contributors
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Anssi Hannula
25
100.00%
1
100.00%
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25
100.00%
1
100.00%



static void uinput_dev_set_autocenter(struct input_dev *dev, u16 magnitude)
{
	uinput_dev_event(dev, EV_FF, FF_AUTOCENTER, magnitude);
}

Contributors
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Anssi Hannula
25
100.00%
1
100.00%
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25
100.00%
1
100.00%



static int uinput_dev_playback(struct input_dev *dev, int effect_id, int value)
{
	return uinput_dev_event(dev, EV_FF, effect_id, value);
}

Contributors
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Anssi Hannula
29
100.00%
1
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29
100.00%
1
100.00%



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);
}

Contributors
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CommitProp
Philip Langdale
23
24.73%
1
12.50%
Micah Dowty
18
19.35%
1
12.50%
Anssi Hannula
17
18.28%
1
12.50%
Aristeu Sergio Rozanski Filho
12
12.90%
1
12.50%
Dmitry Torokhov
12
12.90%
3
37.50%
Zach Welch
11
11.83%
1
12.50%
Total
93
100.00%
8
100.00%



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);
}

Contributors
Person
Tokens
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CommitProp
Micah Dowty
34
50.75%
1
16.67%
Aristeu Sergio Rozanski Filho
12
17.91%
1
16.67%
Dmitry Torokhov
12
17.91%
3
50.00%
Zach Welch
9
13.43%
1
16.67%
Total
67
100.00%
6
100.00%



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;
	}
}

Contributors
Person
Tokens
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CommitProp
Dmitry Torokhov
38
37.25%
1
16.67%
Aristeu Sergio Rozanski Filho
33
32.35%
1
16.67%
Micah Dowty
20
19.61%
1
16.67%
Vojtech Pavlik
7
6.86%
1
16.67%
Zach Welch
2
1.96%
1
16.67%
Randy Dunlap
2
1.96%
1
16.67%
Total
102
100.00%
6
100.00%



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;
	}

	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;
}

Contributors
Person
Tokens
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Commits
CommitProp
Anssi Hannula
92
32.06%
1
12.50%
David Herrmann
65
22.65%
1
12.50%
Dmitry Torokhov
55
19.16%
2
25.00%
Elias Vanderstuyft
34
11.85%
1
12.50%
Micah Dowty
34
11.85%
1
12.50%
Randy Dunlap
6
2.09%
1
12.50%
Vojtech Pavlik
1
0.35%
1
12.50%
Total
287
100.00%
8
100.00%



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;
	nonseekable_open(inode, file);

	return 0;
}

Contributors
Person
Tokens
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CommitProp
Micah Dowty
47
48.45%
1
12.50%
Dmitry Torokhov
25
25.77%
4
50.00%
Vojtech Pavlik
18
18.56%
1
12.50%
Zach Welch
5
5.15%
1
12.50%
Randy Dunlap
2
2.06%
1
12.50%
Total
97
100.00%
8
100.00%



static int uinput_validate_absinfo(struct input_dev *dev, unsigned int code,
				   const struct input_absinfo *abs)
{
	int min, max;

	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 (abs->flat > max - min) {
		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;
}

Contributors
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CommitProp
David Herrmann
40
36.04%
2
28.57%
Micah Dowty
30
27.03%
1
14.29%
Peter Hutterer
26
23.42%
1
14.29%
Vojtech Pavlik
12
10.81%
2
28.57%
Daniel Mack
3
2.70%
1
14.29%
Total
111
100.00%
7
100.00%



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;
}

Contributors
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David Herrmann
78
95.12%
2
40.00%
Zach Welch
2
2.44%
1
20.00%
Vojtech Pavlik
1
1.22%
1
20.00%
Micah Dowty
1
1.22%
1
20.00%
Total
82
100.00%
5
100.00%



static int uinput_allocate_device(struct uinput_device *udev)
{
	udev->dev = input_allocate_device();
	if (!udev->dev)
		return -ENOMEM;

	udev->dev->event = uinput_dev_event;
	input_set_drvdata(udev->dev, udev);

	return 0;
}

Contributors
Person
Tokens
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CommitProp
Dmitry Torokhov
32
65.31%
2
50.00%
Vojtech Pavlik
10
20.41%
1
25.00%
Micah Dowty
7
14.29%
1
25.00%
Total
49
100.00%
4
100.00%



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;
}

Contributors
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Benjamin Tissoires
133
98.52%
1
50.00%
Dmitry Torokhov
2
1.48%
1
50.00%
Total
135
100.00%
2
100.00%



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;
}

Contributors
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Benjamin Tissoires
133
83.65%
1
50.00%
David Herrmann
26
16.35%
1
50.00%
Total
159
100.00%
2
100.00%

/* 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) {
		retval = uinput_allocate_device(udev);
		if (retval)
			return retval;
	}

	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;
}

Contributors
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Dmitry Torokhov
137
41.77%
4
40.00%
Micah Dowty
136
41.46%
1
10.00%
Daniel Mack
27
8.23%
1
10.00%
David Herrmann
15
4.57%
1
10.00%
Anssi Hannula
8
2.44%
1
10.00%
Benjamin Tissoires
3
0.91%
1
10.00%
Ian Campbell
2
0.61%
1
10.00%
Total
328
100.00%
10
100.00%



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();
	}

	return bytes;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Micah Dowty
52
52.53%
1
25.00%
Ryan Mallon
29
29.29%
1
25.00%
Dmitry Torokhov
10
10.10%
1
25.00%
Philip Langdale
8
8.08%
1
25.00%
Total
99
100.00%
4
100.00%



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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
85
85.86%
3
50.00%
Micah Dowty
12
12.12%
1
16.67%
Ryan Mallon
1
1.01%
1
16.67%
Benjamin Tissoires
1
1.01%
1
16.67%
Total
99
100.00%
6
100.00%



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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
84
100.00%
1
100.00%
Total
84
100.00%
1
100.00%



static ssize_t uinput_events_to_user(