v4.19.13 snapshot.
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
new file mode 100644
index 0000000..f48369d
--- /dev/null
+++ b/drivers/input/evdev.c
@@ -0,0 +1,1483 @@
+/*
+ * Event char devices, giving access to raw input device events.
+ *
+ * Copyright (c) 1999-2002 Vojtech Pavlik
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#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"
+
+enum evdev_clock_type {
+ EV_CLK_REAL = 0,
+ EV_CLK_MONO,
+ EV_CLK_BOOT,
+ EV_CLK_MAX
+};
+
+struct evdev {
+ int open;
+ struct input_handle handle;
+ wait_queue_head_t wait;
+ 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 */
+ struct fasync_struct *fasync;
+ struct evdev *evdev;
+ struct list_head node;
+ unsigned int clk_type;
+ bool revoked;
+ unsigned long *evmasks[EV_CNT];
+ unsigned int bufsize;
+ struct input_event buffer[];
+};
+
+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)
+{
+ struct input_event ev;
+ ktime_t time;
+ struct timespec64 ts;
+
+ time = client->clk_type == EV_CLK_REAL ?
+ ktime_get_real() :
+ client->clk_type == EV_CLK_MONO ?
+ ktime_get() :
+ ktime_get_boottime();
+
+ ts = ktime_to_timespec64(time);
+ 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;
+ unsigned int clk_type;
+
+ switch (clkid) {
+
+ case CLOCK_REALTIME:
+ clk_type = EV_CLK_REAL;
+ break;
+ case CLOCK_MONOTONIC:
+ clk_type = EV_CLK_MONO;
+ break;
+ case CLOCK_BOOTTIME:
+ clk_type = EV_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].input_event_sec =
+ event->input_event_sec;
+ client->buffer[client->tail].input_event_usec =
+ event->input_event_usec;
+ client->buffer[client->tail].type = EV_SYN;
+ client->buffer[client->tail].code = SYN_DROPPED;
+ client->buffer[client->tail].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)
+{
+ struct evdev *evdev = client->evdev;
+ 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(&evdev->wait);
+}
+
+/*
+ * Pass incoming events to all connected clients.
+ */
+static void evdev_events(struct input_handle *handle,
+ const struct input_value *vals, unsigned int count)
+{
+ struct evdev *evdev = handle->private;
+ struct evdev_client *client;
+ ktime_t ev_time[EV_CLK_MAX];
+
+ ev_time[EV_CLK_MONO] = ktime_get();
+ ev_time[EV_CLK_REAL] = ktime_mono_to_real(ev_time[EV_CLK_MONO]);
+ ev_time[EV_CLK_BOOT] = ktime_mono_to_any(ev_time[EV_CLK_MONO],
+ TK_OFFS_BOOT);
+
+ 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();
+}
+
+/*
+ * Pass incoming event to all connected clients.
+ */
+static void evdev_event(struct input_handle *handle,
+ unsigned int type, unsigned int code, int value)
+{
+ struct input_value vals[] = { { type, code, value } };
+
+ evdev_events(handle, vals, 1);
+}
+
+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 int evdev_flush(struct file *file, fl_owner_t id)
+{
+ struct evdev_client *client = file->private_data;
+ struct evdev *evdev = client->evdev;
+
+ mutex_lock(&evdev->mutex);
+
+ if (evdev->exist && !client->revoked)
+ input_flush_device(&evdev->handle, file);
+
+ mutex_unlock(&evdev->mutex);
+ return 0;
+}
+
+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);
+ spin_unlock(&evdev->client_lock);
+
+ wake_up_interruptible(&evdev->wait);
+}
+
+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);
+ 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);
+ unsigned int size = sizeof(struct evdev_client) +
+ bufsize * sizeof(struct input_event);
+ struct evdev_client *client;
+ int error;
+
+ client = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
+ if (!client)
+ client = vzalloc(size);
+ if (!client)
+ return -ENOMEM;
+
+ 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;
+ nonseekable_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;
+
+ 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(evdev->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, &evdev->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(&evdev->wait);
+
+ 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,
+ .flush = evdev_flush,
+ .llseek = no_llseek,
+};
+
+/*
+ * 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);
+ init_waitqueue_head(&evdev->wait);
+ 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 = {
+ .event = evdev_event,
+ .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 <vojtech@ucw.cz>");
+MODULE_DESCRIPTION("Input driver event char devices");
+MODULE_LICENSE("GPL");