// SPDX-License-Identifier: GPL-2.0-only
/*
* Event char devices, giving access to raw input device events.
*
* Copyright (c) 1999-2002 Vojtech Pavlik
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#define EVDEV_MINOR_BASE 64
#define EVDEV_MINORS 32
#define EVDEV_MIN_BUFFER_SIZE 64U
#define EVDEV_BUF_PACKETS 8
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/input/mt.h>
#include <linux/major.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include "input-compat.h"
struct evdev {
int open;
struct input_handle handle;
struct evdev_client __rcu *grab;
struct list_head client_list;
spinlock_t client_lock; /* protects client_list */
struct mutex mutex;
struct device dev;
struct cdev cdev;
bool exist;
};
struct evdev_client {
unsigned int head;
unsigned int tail;
unsigned int packet_head; /* [future] position of the first element of next packet */
spinlock_t buffer_lock; /* protects access to buffer, head and tail */
wait_queue_head_t wait;
struct fasync_struct *fasync;
struct evdev *evdev;
struct list_head node;
enum input_clock_type clk_type;
bool revoked;
unsigned long *evmasks[EV_CNT];
unsigned int bufsize;
struct input_event buffer[] __counted_by(bufsize);
};
static size_t evdev_get_mask_cnt(unsigned int type)
{
static const size_t counts[EV_CNT] = {
/* EV_SYN==0 is EV_CNT, _not_ SYN_CNT, see EVIOCGBIT */
[EV_SYN] = EV_CNT,
[EV_KEY] = KEY_CNT,
[EV_REL] = REL_CNT,
[EV_ABS] = ABS_CNT,
[EV_MSC] = MSC_CNT,
[EV_SW] = SW_CNT,
[EV_LED] = LED_CNT,
[EV_SND] = SND_CNT,
[EV_FF] = FF_CNT,
};
return (type < EV_CNT) ? counts[type] : 0;
}
/* requires the buffer lock to be held */
static bool __evdev_is_filtered(struct evdev_client *client,
unsigned int type,
unsigned int code)
{
unsigned long *mask;
size_t cnt;
/* EV_SYN and unknown codes are never filtered */
if (type == EV_SYN || type >= EV_CNT)
return false;
/* first test whether the type is filtered */
mask = client->evmasks[0];
if (mask && !test_bit(type, mask))
return true;
/* unknown values are never filtered */
cnt = evdev_get_mask_cnt(type);
if (!cnt || code >= cnt)
return false;
mask = client->evmasks[type];
return mask && !test_bit(code, mask);
}
/* flush queued events of type @type, caller must hold client->buffer_lock */
static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
{
unsigned int i, head, num;
unsigned int mask = client->bufsize - 1;
bool is_report;
struct input_event *ev;
BUG_ON(type == EV_SYN);
head = client->tail;
client->packet_head = client->tail;
/* init to 1 so a leading SYN_REPORT will not be dropped */
num = 1;
for (i = client->tail; i != client->head; i = (i + 1) & mask) {
ev = &client->buffer[i];
is_report = ev->type == EV_SYN && ev->code == SYN_REPORT;
if (ev->type == type) {
/* drop matched entry */
continue;
} else if (is_report && !num) {
/* drop empty SYN_REPORT groups */
continue;
} else if (head != i) {
/* move entry to fill the gap */
client->buffer[head] = *ev;
}
num++;
head = (head + 1) & mask;
if (is_report) {
num = 0;
client->packet_head = head;
}
}
client->head = head;
}
static void __evdev_queue_syn_dropped(struct evdev_client *client)
{
ktime_t *ev_time = input_get_timestamp(client->evdev->handle.dev);
struct timespec64 ts = ktime_to_timespec64(ev_time[client->clk_type]);
struct input_event ev;
ev.input_event_sec = ts.tv_sec;
ev.input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
ev.type = EV_SYN;
ev.code = SYN_DROPPED;
ev.value = 0;
client->buffer[client->head++] = ev;
client->head &= client->bufsize - 1;
if (unlikely(client->head == client->tail)) {
/* drop queue but keep our SYN_DROPPED event */
client->tail = (client->head - 1) & (client->bufsize - 1);
client->packet_head = client->tail;
}
}
static void evdev_queue_syn_dropped(struct evdev_client *client)
{
unsigned long flags;
spin_lock_irqsave(&client->buffer_lock, flags);
__evdev_queue_syn_dropped(client);
spin_unlock_irqrestore(&client->buffer_lock, flags);
}
static int evdev_set_clk_type(struct evdev_client *client, unsigned int clkid)
{
unsigned long flags;
enum input_clock_type clk_type;
switch (clkid) {
case CLOCK_REALTIME:
clk_type = INPUT_CLK_REAL;
break;
case CLOCK_MONOTONIC:
clk_type = INPUT_CLK_MONO;
break;
case CLOCK_BOOTTIME:
clk_type = INPUT_CLK_BOOT;
break;
default:
return -EINVAL;
}
if (client->clk_type != clk_type) {
client->clk_type = clk_type;
/*
* Flush pending events and queue SYN_DROPPED event,
* but only if the queue is not empty.
*/
spin_lock_irqsave(&client->buffer_lock, flags);
if (client->head != client->tail) {
client->packet_head = client->head = client->tail;
__evdev_queue_syn_dropped(client);
}
spin_unlock_irqrestore(&client->buffer_lock, flags);
}
return 0;
}
static void __pass_event(struct evdev_client *client,
const struct input_event *event)
{
client->buffer[client->head++] = *event;
client->head &= client->bufsize - 1;
if (unlikely(client->head == client->tail)) {
/*
* This effectively "drops" all unconsumed events, leaving
* EV_SYN/SYN_DROPPED plus the newest event in the queue.
*/
client->tail = (client->head - 2) & (client->bufsize - 1);
client->buffer[client->tail] = (struct input_event) {
.input_event_sec = event->input_event_sec,
.input_event_usec = event->input_event_usec,
.type = EV_SYN,
.code = SYN_DROPPED,
.value = 0,
};
client->packet_head = client->tail;
}
if (event->type == EV_SYN && event->code == SYN_REPORT) {
client->packet_head = client->head;
kill_fasync(&client->fasync, SIGIO, POLL_IN);
}
}
static void evdev_pass_values(struct evdev_client *client,
const struct input_value *vals, unsigned int count,
ktime_t *ev_time)
{
const struct input_value *v;
struct input_event event;
struct timespec64 ts;
bool wakeup = false;
if (client->revoked)
return;
ts = ktime_to_timespec64(ev_time[client->clk_type]);
event.input_event_sec = ts.tv_sec;
event.input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
/* Interrupts are disabled, just acquire the lock. */
spin_lock(&client->buffer_lock);
for (v = vals; v != vals + count; v++) {
if (__evdev_is_filtered(client, v->type, v->code))
continue;
if (v->type == EV_SYN && v->code == SYN_REPORT) {
/* drop empty SYN_REPORT */
if (client->packet_head == client->head)
continue;
wakeup = true;
}
event.type = v->type;
event.code = v->code;
event.value = v->value;
__pass_event(client, &event);
}
spin_unlock(&client->buffer_lock);
if (wakeup)
wake_up_interruptible_poll(&client->wait,
EPOLLIN | EPOLLOUT | EPOLLRDNORM | EPOLLWRNORM);
}
/*
* Pass incoming events to all connected clients.
*/
static unsigned int evdev_events(struct input_handle *handle,
struct input_value *vals, unsigned int count)
{
struct evdev *evdev = handle->private;
struct evdev_client *client;
ktime_t *ev_time = input_get_timestamp(handle->dev);
rcu_read_lock();
client = rcu_dereference(evdev->grab);
if (client)
evdev_pass_values(client, vals, count, ev_time);
else
list_for_each_entry_rcu(client, &evdev->client_list, node)
evdev_pass_values(client, vals, count, ev_time);
rcu_read_unlock();
return count;
}
static int evdev_fasync(int fd, struct file *file, int on)
{
struct evdev_client *client = file->private_data;
return fasync_helper(fd, file, on, &client->fasync);
}
static void evdev_free(struct device *dev)
{
struct evdev *evdev = container_of(dev, struct evdev, dev);
input_put_device(evdev->handle.dev);
kfree(evdev);
}
/*
* Grabs an event device (along with underlying input device).
* This function is called with evdev->mutex taken.
*/
static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
{
int error;
if (evdev->grab)
return -EBUSY;
error = input_grab_device(&evdev->handle);
if (error)
return error;
rcu_assign_pointer(evdev->grab, client);
return 0;
}
static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
{
struct evdev_client *grab = rcu_dereference_protected(evdev->grab,
lockdep_is_held(&evdev->mutex));
if (grab != client)
return -EINVAL;
rcu_assign_pointer(evdev->grab, NULL);
synchronize_rcu();
input_release_device(&evdev->handle);
return 0;
}
static void evdev_attach_client(struct evdev *evdev,
struct evdev_client *client)
{
spin_lock(&evdev->client_lock);
list_add_tail_rcu(&client->node, &evdev->client_list);
spin_unlock(&evdev->client_lock);
}
static void evdev_detach_client(struct evdev *evdev,
struct evdev_client *client)
{
spin_lock(&evdev->client_lock);
list_del_rcu(&client->node);
spin_unlock(&evdev->client_lock);
synchronize_rcu();
}
static int evdev_open_device(struct evdev *evdev)
{
int retval;
retval = mutex_lock_interruptible(&evdev->mutex);
if (retval)
return retval;
if (!evdev->exist)
retval = -ENODEV;
else if (!evdev->open++) {
retval = input_open_device(&evdev->handle);
if (retval)
evdev->open--;
}
mutex_unlock(&evdev->mutex);
return retval;
}
static void evdev_close_device(struct evdev *evdev)
{
mutex_lock(&evdev->mutex);
if (evdev->exist && !--evdev->open)
input_close_device(&evdev->handle);
mutex_unlock(&evdev->mutex);
}
/*
* Wake up users waiting for IO so they can disconnect from
* dead device.
*/
static void evdev_hangup(struct evdev *evdev)
{
struct evdev_client *client;
spin_lock(&evdev->client_lock);
list_for_each_entry(client, &evdev->client_list, node) {
kill_fasync(&client->fasync, SIGIO, POLL_HUP);
wake_up_interruptible_poll(&client->wait, EPOLLHUP | EPOLLERR);
}
spin_unlock(&evdev->client_lock);
}
static int evdev_release(struct inode *inode, struct file *file)
{
struct evdev_client *client = file->private_data;
struct evdev *evdev = client->evdev;
unsigned int i;
mutex_lock(&evdev->mutex);
if (evdev->exist && !client->revoked)
input_flush_device(&evdev->handle, file);
evdev_ungrab(evdev, client);
mutex_unlock(&evdev->mutex);
evdev_detach_client(evdev, client);
for (i = 0; i < EV_CNT; ++i)
bitmap_free(client->evmasks[i]);
kvfree(client);
evdev_close_device(evdev);
return 0;
}
static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
{
unsigned int n_events =
max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
EVDEV_MIN_BUFFER_SIZE);
return roundup_pow_of_two(n_events);
}
static int evdev_open(struct inode *inode, struct file *file)
{
struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev);
unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev);
struct evdev_client *client;
int error;
client = kvzalloc(struct_size(client, buffer, bufsize), GFP_KERNEL);
if (!client)
return -ENOMEM;
init_waitqueue_head(&client->wait);
client->bufsize = bufsize;
spin_lock_init(&client->buffer_lock);
client->evdev = evdev;
evdev_attach_client(evdev, client);
error = evdev_open_device(evdev);
if (error)
goto err_free_client;
file->private_data = client;
stream_open(inode, file);
return 0;
err_free_client:
evdev_detach_client(evdev, client);
kvfree(client);
return error;
}
static ssize_t evdev_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos)
{
struct evdev_client *client = file->private_data;
struct evdev *evdev = client->evdev;
struct input_event event;
int retval = 0;
/*
* Limit amount of data we inject into the input subsystem so that
* we do not hold evdev->mutex for too long. 4096 bytes corresponds
* to 170 input events.
*/
count = min(count, 4096);
if (count != 0 && count < input_event_size())
return -EINVAL;
retval = mutex_lock_interruptible(&evdev->mutex);
if (retval)
return retval;
if (!evdev->exist || client->revoked) {
retval = -ENODEV;
goto out;
}
while (retval + input_event_size() <= count) {
if (input_event_from_user(buffer + retval, &event)) {
retval = -EFAULT;
goto out;
}
retval += input_event_size();
input_inject_event(&evdev->handle,
event.type, event.code, event.value);
cond_resched();
}
out:
mutex_unlock(&evdev->mutex);
return retval;
}
static int evdev_fetch_next_event(struct evdev_client *client,
struct input_event *event)
{
int have_event;
spin_lock_irq(&client->buffer_lock);
have_event = client->packet_head != client->tail;
if (have_event) {
*event = client->buffer[client->tail++];
client->tail &= client->bufsize - 1;
}
spin_unlock_irq(&client->buffer_lock);
return have_event;
}
static ssize_t evdev_read(struct file *file, char __user *buffer,
size_t count, loff_t *ppos)
{
struct evdev_client *client = file->private_data;
struct evdev *evdev = client->evdev;
struct input_event event;
size_t read = 0;
int error;
if (count != 0 && count < input_event_size())
return -EINVAL;
for (;;) {
if (!evdev->exist || client->revoked)
return -ENODEV;
if (client->packet_head == client->tail &&
(file->f_flags & O_NONBLOCK))
return -EAGAIN;
/*
* count == 0 is special - no IO is done but we check
* for error conditions (see above).
*/
if (count == 0)
break;
while (read + input_event_size() <= count &&
evdev_fetch_next_event(client, &event)) {
if (input_event_to_user(buffer + read, &event))
return -EFAULT;
read += input_event_size();
}
if (read)
break;
if (!(file->f_flags & O_NONBLOCK)) {
error = wait_event_interruptible(client->wait,
client->packet_head != client->tail ||
!evdev->exist || client->revoked);
if (error)
return error;
}
}
return read;
}
/* No kernel lock - fine */
static __poll_t evdev_poll(struct file *file, poll_table *wait)
{
struct evdev_client *client = file->private_data;
struct evdev *evdev = client->evdev;
__poll_t mask;
poll_wait(file, &client->wait, wait);
if (evdev->exist && !client->revoked)
mask = EPOLLOUT | EPOLLWRNORM;
else
mask = EPOLLHUP | EPOLLERR;
if (client->packet_head != client->tail)
mask |= EPOLLIN | EPOLLRDNORM;
return mask;
}
#ifdef CONFIG_COMPAT
#define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
#define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
#ifdef __BIG_ENDIAN
static int bits_to_user(unsigned long *bits, unsigned int maxbit,
unsigned int maxlen, void __user *p, int compat)
{
int len, i;
if (compat) {
len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
if (len > maxlen)
len = maxlen;
for (i = 0; i < len / sizeof(compat_long_t); i++)
if (copy_to_user((compat_long_t __user *) p + i,
(compat_long_t *) bits +
i + 1 - ((i % 2) << 1),
sizeof(compat_long_t)))
return -EFAULT;
} else {
len = BITS_TO_LONGS(maxbit) * sizeof(long);
if (len > maxlen)
len = maxlen;
if (copy_to_user(p, bits, len))
return -EFAULT;
}
return len;
}
static int bits_from_user(unsigned long *bits, unsigned int maxbit,
unsigned int maxlen, const void __user *p, int compat)
{
int len, i;
if (compat) {
if (maxlen % sizeof(compat_long_t))
return -EINVAL;
len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
if (len > maxlen)
len = maxlen;
for (i = 0; i < len / sizeof(compat_long_t); i++)
if (copy_from_user((compat_long_t *) bits +
i + 1 - ((i % 2) << 1),
(compat_long_t __user *) p + i,
sizeof(compat_long_t)))
return -EFAULT;
if (i % 2)
*((compat_long_t *) bits + i - 1) = 0;
} else {
if (maxlen % sizeof(long))
return -EINVAL;
len = BITS_TO_LONGS(maxbit) * sizeof(long);
if (len > maxlen)
len = maxlen;
if (copy_from_user(bits, p, len))
return -EFAULT;
}
return len;
}
#else
static int bits_to_user(unsigned long *bits, unsigned int maxbit,
unsigned int maxlen, void __user *p, int compat)
{
int len = compat ?
BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
BITS_TO_LONGS(maxbit) * sizeof(long);
if (len > maxlen)
len = maxlen;
return copy_to_user(p, bits, len) ? -EFAULT : len;
}
static int bits_from_user(unsigned long *bits, unsigned int maxbit,
unsigned int maxlen, const void __user *p, int compat)
{
size_t chunk_size = compat ? sizeof(compat_long_t) : sizeof(long);
int len;
if (maxlen % chunk_size)
return -EINVAL;
len = compat ? BITS_TO_LONGS_COMPAT(maxbit) : BITS_TO_LONGS(maxbit);
len *= chunk_size;
if (len > maxlen)
len = maxlen;
return copy_from_user(bits, p, len) ? -EFAULT : len;
}
#endif /* __BIG_ENDIAN */
#else
static int bits_to_user(unsigned long *bits, unsigned int maxbit,
unsigned int maxlen, void __user *p, int compat)
{
int len = BITS_TO_LONGS(maxbit) * sizeof(long);
if (len > maxlen)
len = maxlen;
return copy_to_user(p, bits, len) ? -EFAULT : len;
}
static int bits_from_user(unsigned long *bits, unsigned int maxbit,
unsigned int maxlen, const void __user *p, int compat)
{
int len;
if (maxlen % sizeof(long))
return -EINVAL;
len = BITS_TO_LONGS(maxbit) * sizeof(long);
if (len > maxlen)
len = maxlen;
return copy_from_user(bits, p, len) ? -EFAULT : len;
}
#endif /* CONFIG_COMPAT */
static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
{
int len;
if (!str)
return -ENOENT;
len = strlen(str) + 1;
if (len > maxlen)
len = maxlen;
return copy_to_user(p, str, len) ? -EFAULT : len;
}
static int handle_eviocgbit(struct input_dev *dev,
unsigned int type, unsigned int size,
void __user *p, int compat_mode)
{
unsigned long *bits;
int len;
switch (type) {
case 0: bits = dev->evbit; len = EV_MAX; break;
case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
case EV_REL: bits = dev->relbit; len = REL_MAX; break;
case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
case EV_SW: bits = dev->swbit; len = SW_MAX; break;
default: return -EINVAL;
}
return bits_to_user(bits, len, size, p, compat_mode);
}
static int evdev_handle_get_keycode(struct input_dev *dev, void __user *p)
{
struct input_keymap_entry ke = {
.len = sizeof(unsigned int),
.flags = 0,
};
int __user *ip = (int __user *)p;
int error;
/* legacy case */
if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
return -EFAULT;
error = input_get_keycode(dev, &ke);
if (error)
return error;
if (put_user(ke.keycode, ip + 1))
return -EFAULT;
return 0;
}
static int evdev_handle_get_keycode_v2(struct input_dev *dev, void __user *p)
{
struct input_keymap_entry ke;
int error;
if (copy_from_user(&ke, p, sizeof(ke)))
return -EFAULT;
error = input_get_keycode(dev, &ke);
if (error)
return error;
if (copy_to_user(p, &ke, sizeof(ke)))
return -EFAULT;
return 0;
}
static int evdev_handle_set_keycode(struct input_dev *dev, void __user *p)
{
struct input_keymap_entry ke = {
.len = sizeof(unsigned int),
.flags = 0,
};
int __user *ip = (int __user *)p;
if (copy_from_user(ke.scancode, p, sizeof(unsigned int)))
return -EFAULT;
if (get_user(ke.keycode, ip + 1))
return -EFAULT;
return input_set_keycode(dev, &ke);
}
static int evdev_handle_set_keycode_v2(struct input_dev *dev, void __user *p)
{
struct input_keymap_entry ke;
if (copy_from_user(&ke, p, sizeof(ke)))
return -EFAULT;
if (ke.len > sizeof(ke.scancode))
return -EINVAL;
return input_set_keycode(dev, &ke);
}
/*
* If we transfer state to the user, we should flush all pending events
* of the same type from the client's queue. Otherwise, they might end up
* with duplicate events, which can screw up client's state tracking.
* If bits_to_user fails after flushing the queue, we queue a SYN_DROPPED
* event so user-space will notice missing events.
*
* LOCKING:
* We need to take event_lock before buffer_lock to avoid dead-locks. But we
* need the even_lock only to guarantee consistent state. We can safely release
* it while flushing the queue. This allows input-core to handle filters while
* we flush the queue.
*/
static int evdev_handle_get_val(struct evdev_client *client,
struct input_dev *dev, unsigned int type,
unsigned long *bits, unsigned int maxbit,
unsigned int maxlen, void __user *p,
int compat)
{
int ret;
unsigned long *mem;
mem = bitmap_alloc(maxbit, GFP_KERNEL);
if (!mem)
return -ENOMEM;
spin_lock_irq(&dev->event_lock);
spin_lock(&client->buffer_lock);
bitmap_copy(mem, bits, maxbit);
spin_unlock(&dev->event_lock);
__evdev_flush_queue(client, type);
spin_unlock_irq(&client->buffer_lock);
ret = bits_to_user(mem, maxbit, maxlen, p, compat);
if (ret < 0)
evdev_queue_syn_dropped(client);
bitmap_free(mem);
return ret;
}
static int evdev_handle_mt_request(struct input_dev *dev,
unsigned int size,
int __user *ip)
{
const struct input_mt *mt = dev->mt;
unsigned int code;
int max_slots;
int i;
if (get_user(code, &ip[0]))
return -EFAULT;
if (!mt || !input_is_mt_value(code))
return -EINVAL;
max_slots = (size - sizeof(__u32)) / sizeof(__s32);
for (i = 0; i < mt->num_slots && i < max_slots; i++) {
int value = input_mt_get_value(&mt->slots[i], code);
if (put_user(value, &ip[1 + i]))
return -EFAULT;
}
return 0;
}
static int evdev_revoke(struct evdev *evdev, struct evdev_client *client,
struct file *file)
{
client->revoked = true;
evdev_ungrab(evdev, client);
input_flush_device(&evdev->handle, file);
wake_up_interruptible_poll(&client->wait, EPOLLHUP | EPOLLERR);
return 0;
}
/* must be called with evdev-mutex held */
static int evdev_set_mask(struct evdev_client *client,
unsigned int type,
const void __user *codes,
u32 codes_size,
int compat)
{
unsigned long flags, *mask, *oldmask;
size_t cnt;
int error;
/* we allow unknown types and 'codes_size > size' for forward-compat */
cnt = evdev_get_mask_cnt(type);
if (!cnt)
return 0;
mask = bitmap_zalloc(cnt, GFP_KERNEL);
if (!mask)
return -ENOMEM;
error = bits_from_user(mask, cnt - 1, codes_size, codes, compat);
if (error < 0) {
bitmap_free(mask);
return error;
}
spin_lock_irqsave(&client->buffer_lock, flags);
oldmask = client->evmasks[type];
client->evmasks[type] = mask;
spin_unlock_irqrestore(&client->buffer_lock, flags);
bitmap_free(oldmask);
return 0;
}
/* must be called with evdev-mutex held */
static int evdev_get_mask(struct evdev_client *client,
unsigned int type,
void __user *codes,
u32 codes_size,
int compat)
{
unsigned long *mask;
size_t cnt, size, xfer_size;
int i;
int error;
/* we allow unknown types and 'codes_size > size' for forward-compat */
cnt = evdev_get_mask_cnt(type);
size = sizeof(unsigned long) * BITS_TO_LONGS(cnt);
xfer_size = min_t(size_t, codes_size, size);
if (cnt > 0) {
mask = client->evmasks[type];
if (mask) {
error = bits_to_user(mask, cnt - 1,
xfer_size, codes, compat);
if (error < 0)
return error;
} else {
/* fake mask with all bits set */
for (i = 0; i < xfer_size; i++)
if (put_user(0xffU, (u8 __user *)codes + i))
return -EFAULT;
}
}
if (xfer_size < codes_size)
if (clear_user(codes + xfer_size, codes_size - xfer_size))
return -EFAULT;
return 0;
}
static long evdev_do_ioctl(struct file *file, unsigned int cmd,
void __user *p, int compat_mode)
{
struct evdev_client *client = file->private_data;
struct evdev *evdev = client->evdev;
struct input_dev *dev = evdev->handle.dev;
struct input_absinfo abs;
struct input_mask mask;
struct ff_effect effect;
int __user *ip = (int __user *)p;
unsigned int i, t, u, v;
unsigned int size;
int error;
/* First we check for fixed-length commands */
switch (cmd) {
case EVIOCGVERSION:
return put_user(EV_VERSION, ip);
case EVIOCGID:
if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
return -EFAULT;
return 0;
case EVIOCGREP:
if (!test_bit(EV_REP, dev->evbit))
return -ENOSYS;
if (put_user(dev->rep[REP_DELAY], ip))
return -EFAULT;
if (put_user(dev->rep[REP_PERIOD], ip + 1))
return -EFAULT;
return 0;
case EVIOCSREP:
if (!test_bit(EV_REP, dev->evbit))
return -ENOSYS;
if (get_user(u, ip))
return -EFAULT;
if (get_user(v, ip + 1))
return -EFAULT;
input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
return 0;
case EVIOCRMFF:
return input_ff_erase(dev, (int)(unsigned long) p, file);
case EVIOCGEFFECTS:
i = test_bit(EV_FF, dev->evbit) ?
dev->ff->max_effects : 0;
if (put_user(i, ip))
return -EFAULT;
return 0;
case EVIOCGRAB:
if (p)
return evdev_grab(evdev, client);
else
return evdev_ungrab(evdev, client);
case EVIOCREVOKE:
if (p)
return -EINVAL;
else
return evdev_revoke(evdev, client, file);
case EVIOCGMASK: {
void __user *codes_ptr;
if (copy_from_user(&mask, p, sizeof(mask)))
return -EFAULT;
codes_ptr = (void __user *)(unsigned long)mask.codes_ptr;
return evdev_get_mask(client,
mask.type, codes_ptr, mask.codes_size,
compat_mode);
}
case EVIOCSMASK: {
const void __user *codes_ptr;
if (copy_from_user(&mask, p, sizeof(mask)))
return -EFAULT;
codes_ptr = (const void __user *)(unsigned long)mask.codes_ptr;
return evdev_set_mask(client,
mask.type, codes_ptr, mask.codes_size,
compat_mode);
}
case EVIOCSCLOCKID:
if (copy_from_user(&i, p, sizeof(unsigned int)))
return -EFAULT;
return evdev_set_clk_type(client, i);
case EVIOCGKEYCODE:
return evdev_handle_get_keycode(dev, p);
case EVIOCSKEYCODE:
return evdev_handle_set_keycode(dev, p);
case EVIOCGKEYCODE_V2:
return evdev_handle_get_keycode_v2(dev, p);
case EVIOCSKEYCODE_V2:
return evdev_handle_set_keycode_v2(dev, p);
}
size = _IOC_SIZE(cmd);
/* Now check variable-length commands */
#define EVIOC_MASK_SIZE(nr) ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
switch (EVIOC_MASK_SIZE(cmd)) {
case EVIOCGPROP(0):
return bits_to_user(dev->propbit, INPUT_PROP_MAX,
size, p, compat_mode);
case EVIOCGMTSLOTS(0):
return evdev_handle_mt_request(dev, size, ip);
case EVIOCGKEY(0):
return evdev_handle_get_val(client, dev, EV_KEY, dev->key,
KEY_MAX, size, p, compat_mode);
case EVIOCGLED(0):
return evdev_handle_get_val(client, dev, EV_LED, dev->led,
LED_MAX, size, p, compat_mode);
case EVIOCGSND(0):
return evdev_handle_get_val(client, dev, EV_SND, dev->snd,
SND_MAX, size, p, compat_mode);
case EVIOCGSW(0):
return evdev_handle_get_val(client, dev, EV_SW, dev->sw,
SW_MAX, size, p, compat_mode);
case EVIOCGNAME(0):
return str_to_user(dev->name, size, p);
case EVIOCGPHYS(0):
return str_to_user(dev->phys, size, p);
case EVIOCGUNIQ(0):
return str_to_user(dev->uniq, size, p);
case EVIOC_MASK_SIZE(EVIOCSFF):
if (input_ff_effect_from_user(p, size, &effect))
return -EFAULT;
error = input_ff_upload(dev, &effect, file);
if (error)
return error;
if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
return -EFAULT;
return 0;
}
/* Multi-number variable-length handlers */
if (_IOC_TYPE(cmd) != 'E')
return -EINVAL;
if (_IOC_DIR(cmd) == _IOC_READ) {
if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
return handle_eviocgbit(dev,
_IOC_NR(cmd) & EV_MAX, size,
p, compat_mode);
if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
if (!dev->absinfo)
return -EINVAL;
t = _IOC_NR(cmd) & ABS_MAX;
abs = dev->absinfo[t];
if (copy_to_user(p, &abs, min_t(size_t,
size, sizeof(struct input_absinfo))))
return -EFAULT;
return 0;
}
}
if (_IOC_DIR(cmd) == _IOC_WRITE) {
if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
if (!dev->absinfo)
return -EINVAL;
t = _IOC_NR(cmd) & ABS_MAX;
if (copy_from_user(&abs, p, min_t(size_t,
size, sizeof(struct input_absinfo))))
return -EFAULT;
if (size < sizeof(struct input_absinfo))
abs.resolution = 0;
/* We can't change number of reserved MT slots */
if (t == ABS_MT_SLOT)
return -EINVAL;
/*
* Take event lock to ensure that we are not
* changing device parameters in the middle
* of event.
*/
spin_lock_irq(&dev->event_lock);
dev->absinfo[t] = abs;
spin_unlock_irq(&dev->event_lock);
return 0;
}
}
return -EINVAL;
}
static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
void __user *p, int compat_mode)
{
struct evdev_client *client = file->private_data;
struct evdev *evdev = client->evdev;
int retval;
retval = mutex_lock_interruptible(&evdev->mutex);
if (retval)
return retval;
if (!evdev->exist || client->revoked) {
retval = -ENODEV;
goto out;
}
retval = evdev_do_ioctl(file, cmd, p, compat_mode);
out:
mutex_unlock(&evdev->mutex);
return retval;
}
static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
}
#ifdef CONFIG_COMPAT
static long evdev_ioctl_compat(struct file *file,
unsigned int cmd, unsigned long arg)
{
return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
}
#endif
static const struct file_operations evdev_fops = {
.owner = THIS_MODULE,
.read = evdev_read,
.write = evdev_write,
.poll = evdev_poll,
.open = evdev_open,
.release = evdev_release,
.unlocked_ioctl = evdev_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = evdev_ioctl_compat,
#endif
.fasync = evdev_fasync,
};
/*
* Mark device non-existent. This disables writes, ioctls and
* prevents new users from opening the device. Already posted
* blocking reads will stay, however new ones will fail.
*/
static void evdev_mark_dead(struct evdev *evdev)
{
mutex_lock(&evdev->mutex);
evdev->exist = false;
mutex_unlock(&evdev->mutex);
}
static void evdev_cleanup(struct evdev *evdev)
{
struct input_handle *handle = &evdev->handle;
evdev_mark_dead(evdev);
evdev_hangup(evdev);
/* evdev is marked dead so no one else accesses evdev->open */
if (evdev->open) {
input_flush_device(handle, NULL);
input_close_device(handle);
}
}
/*
* Create new evdev device. Note that input core serializes calls
* to connect and disconnect.
*/
static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
const struct input_device_id *id)
{
struct evdev *evdev;
int minor;
int dev_no;
int error;
minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true);
if (minor < 0) {
error = minor;
pr_err("failed to reserve new minor: %d\n", error);
return error;
}
evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
if (!evdev) {
error = -ENOMEM;
goto err_free_minor;
}
INIT_LIST_HEAD(&evdev->client_list);
spin_lock_init(&evdev->client_lock);
mutex_init(&evdev->mutex);
evdev->exist = true;
dev_no = minor;
/* Normalize device number if it falls into legacy range */
if (dev_no < EVDEV_MINOR_BASE + EVDEV_MINORS)
dev_no -= EVDEV_MINOR_BASE;
dev_set_name(&evdev->dev, "event%d", dev_no);
evdev->handle.dev = input_get_device(dev);
evdev->handle.name = dev_name(&evdev->dev);
evdev->handle.handler = handler;
evdev->handle.private = evdev;
evdev->dev.devt = MKDEV(INPUT_MAJOR, minor);
evdev->dev.class = &input_class;
evdev->dev.parent = &dev->dev;
evdev->dev.release = evdev_free;
device_initialize(&evdev->dev);
error = input_register_handle(&evdev->handle);
if (error)
goto err_free_evdev;
cdev_init(&evdev->cdev, &evdev_fops);
error = cdev_device_add(&evdev->cdev, &evdev->dev);
if (error)
goto err_cleanup_evdev;
return 0;
err_cleanup_evdev:
evdev_cleanup(evdev);
input_unregister_handle(&evdev->handle);
err_free_evdev:
put_device(&evdev->dev);
err_free_minor:
input_free_minor(minor);
return error;
}
static void evdev_disconnect(struct input_handle *handle)
{
struct evdev *evdev = handle->private;
cdev_device_del(&evdev->cdev, &evdev->dev);
evdev_cleanup(evdev);
input_free_minor(MINOR(evdev->dev.devt));
input_unregister_handle(handle);
put_device(&evdev->dev);
}
static const struct input_device_id evdev_ids[] = {
{ .driver_info = 1 }, /* Matches all devices */
{ }, /* Terminating zero entry */
};
MODULE_DEVICE_TABLE(input, evdev_ids);
static struct input_handler evdev_handler = {
.events = evdev_events,
.connect = evdev_connect,
.disconnect = evdev_disconnect,
.legacy_minors = true,
.minor = EVDEV_MINOR_BASE,
.name = "evdev",
.id_table = evdev_ids,
};
static int __init evdev_init(void)
{
return input_register_handler(&evdev_handler);
}
static void __exit evdev_exit(void)
{
input_unregister_handler(&evdev_handler);
}
module_init(evdev_init);
module_exit(evdev_exit);
MODULE_AUTHOR("Vojtech Pavlik <[email protected]>");
MODULE_DESCRIPTION("Input driver event char devices");
MODULE_LICENSE("GPL");
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