diff options
Diffstat (limited to 'drivers/input/evdev.c')
| -rw-r--r-- | drivers/input/evdev.c | 1446 |
1 files changed, 1446 insertions, 0 deletions
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c new file mode 100644 index 000000000..95f90699d --- /dev/null +++ b/drivers/input/evdev.c @@ -0,0 +1,1446 @@ +// 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[]; +}; + +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 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 = 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(); +} + +/* + * 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 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; + + 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, + .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); + 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"); |