/* * 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/module.h>#include <linux/init.h>#include <linux/input.h>#include <linux/major.h>#include <linux/device.h>#include "input-compat.h" struct evdev { int open; int minor; 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; 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 bufsize; struct input_event buffer[];}; static struct evdev *evdev_table[EVDEV_MINORS];static DEFINE_MUTEX(evdev_table_mutex); static void evdev_pass_event(struct evdev_client *client, struct input_event *event){ /* Interrupts are disabled, just acquire the lock. */ spin_lock(&client->buffer_lock); 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].time = event->time; 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); } spin_unlock(&client->buffer_lock);} /* * Pass incoming event to all connected clients. */static void evdev_event(struct input_handle *handle, unsigned int type, unsigned int code, int value){ struct evdev *evdev = handle->private; struct evdev_client *client; struct input_event event; do_gettimeofday(&event.time); event.type = type; event.code = code; event.value = value; rcu_read_lock(); client = rcu_dereference(evdev->grab); if (client) evdev_pass_event(client, &event); else list_for_each_entry_rcu(client, &evdev->client_list, node) evdev_pass_event(client, &event); rcu_read_unlock(); wake_up_interruptible(&evdev->wait);} 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; int retval; retval = mutex_lock_interruptible(&evdev->mutex); if (retval) return retval; if (!evdev->exist) retval = -ENODEV; else retval = input_flush_device(&evdev->handle, file); mutex_unlock(&evdev->mutex); return retval;} 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){ if (evdev->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; mutex_lock(&evdev->mutex); if (evdev->grab == client) evdev_ungrab(evdev, client); mutex_unlock(&evdev->mutex); evdev_detach_client(evdev, client); kfree(client); evdev_close_device(evdev); put_device(&evdev->dev); 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; struct evdev_client *client; int i = iminor(inode) - EVDEV_MINOR_BASE; unsigned int bufsize; int error; if (i >= EVDEV_MINORS) return -ENODEV; error = mutex_lock_interruptible(&evdev_table_mutex); if (error) return error; evdev = evdev_table[i]; if (evdev) get_device(&evdev->dev); mutex_unlock(&evdev_table_mutex); if (!evdev) return -ENODEV; bufsize = evdev_compute_buffer_size(evdev->handle.dev); client = kzalloc(sizeof(struct evdev_client) + bufsize * sizeof(struct input_event), GFP_KERNEL); if (!client) { error = -ENOMEM; goto err_put_evdev; } 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); kfree(client); err_put_evdev: put_device(&evdev->dev); 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; if (count < input_event_size()) return -EINVAL; retval = mutex_lock_interruptible(&evdev->mutex); if (retval) return retval; if (!evdev->exist) { retval = -ENODEV; goto out; } do { 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); } while (retval + input_event_size() <= count); 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->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; int retval; if (count < input_event_size()) return -EINVAL; if (client->packet_head == client->tail && evdev->exist && (file->f_flags & O_NONBLOCK)) return -EAGAIN; retval = wait_event_interruptible(evdev->wait, client->packet_head != client->tail || !evdev->exist); if (retval) return retval; if (!evdev->exist) return -ENODEV; while (retval + input_event_size() <= count && evdev_fetch_next_event(client, &event)) { if (input_event_to_user(buffer + retval, &event)) return -EFAULT; retval += input_event_size(); } return retval;} /* No kernel lock - fine */static unsigned int evdev_poll(struct file *file, poll_table *wait){ struct evdev_client *client = file->private_data; struct evdev *evdev = client->evdev; unsigned int mask; poll_wait(file, &evdev->wait, wait); mask = evdev->exist ? POLLOUT | POLLWRNORM : POLLHUP | POLLERR; if (client->packet_head != client->tail) mask |= POLLIN | POLLRDNORM; 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_ENDIANstatic 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;}#elsestatic 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;}#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;} #endif /* CONFIG_COMPAT */ static int str_to_user(const char *str, unsigned int maxlen, void __user *p){ int len; if (!str)Lines 1–500 of 1012. Load more
/* * 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/module.h> #include <linux/init.h> #include <linux/input.h> #include <linux/major.h> #include <linux/device.h> #include "input-compat.h" struct evdev { int open; int minor; 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; 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 bufsize; struct input_event buffer[]; }; static struct evdev *evdev_table[EVDEV_MINORS]; static DEFINE_MUTEX(evdev_table_mutex); static void evdev_pass_event(struct evdev_client *client, struct input_event *event) { /* Interrupts are disabled, just acquire the lock. */ spin_lock(&client->buffer_lock); 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].time = event->time; 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); } spin_unlock(&client->buffer_lock); } /* * Pass incoming event to all connected clients. */ static void evdev_event(struct input_handle *handle, unsigned int type, unsigned int code, int value) { struct evdev *evdev = handle->private; struct evdev_client *client; struct input_event event; do_gettimeofday(&event.time); event.type = type; event.code = code; event.value = value; rcu_read_lock(); client = rcu_dereference(evdev->grab); if (client) evdev_pass_event(client, &event); else list_for_each_entry_rcu(client, &evdev->client_list, node) evdev_pass_event(client, &event); rcu_read_unlock(); wake_up_interruptible(&evdev->wait); } 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; int retval; retval = mutex_lock_interruptible(&evdev->mutex); if (retval) return retval; if (!evdev->exist) retval = -ENODEV; else retval = input_flush_device(&evdev->handle, file); mutex_unlock(&evdev->mutex); return retval; } 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) { if (evdev->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; mutex_lock(&evdev->mutex); if (evdev->grab == client) evdev_ungrab(evdev, client); mutex_unlock(&evdev->mutex); evdev_detach_client(evdev, client); kfree(client); evdev_close_device(evdev); put_device(&evdev->dev); 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; struct evdev_client *client; int i = iminor(inode) - EVDEV_MINOR_BASE; unsigned int bufsize; int error; if (i >= EVDEV_MINORS) return -ENODEV; error = mutex_lock_interruptible(&evdev_table_mutex); if (error) return error; evdev = evdev_table[i]; if (evdev) get_device(&evdev->dev); mutex_unlock(&evdev_table_mutex); if (!evdev) return -ENODEV; bufsize = evdev_compute_buffer_size(evdev->handle.dev); client = kzalloc(sizeof(struct evdev_client) + bufsize * sizeof(struct input_event), GFP_KERNEL); if (!client) { error = -ENOMEM; goto err_put_evdev; } 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); kfree(client); err_put_evdev: put_device(&evdev->dev); 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; if (count < input_event_size()) return -EINVAL; retval = mutex_lock_interruptible(&evdev->mutex); if (retval) return retval; if (!evdev->exist) { retval = -ENODEV; goto out; } do { 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); } while (retval + input_event_size() <= count); 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->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; int retval; if (count < input_event_size()) return -EINVAL; if (client->packet_head == client->tail && evdev->exist && (file->f_flags & O_NONBLOCK)) return -EAGAIN; retval = wait_event_interruptible(evdev->wait, client->packet_head != client->tail || !evdev->exist); if (retval) return retval; if (!evdev->exist) return -ENODEV; while (retval + input_event_size() <= count && evdev_fetch_next_event(client, &event)) { if (input_event_to_user(buffer + retval, &event)) return -EFAULT; retval += input_event_size(); } return retval; } /* No kernel lock - fine */ static unsigned int evdev_poll(struct file *file, poll_table *wait) { struct evdev_client *client = file->private_data; struct evdev *evdev = client->evdev; unsigned int mask; poll_wait(file, &evdev->wait, wait); mask = evdev->exist ? POLLOUT | POLLWRNORM : POLLHUP | POLLERR; if (client->packet_head != client->tail) mask |= POLLIN | POLLRDNORM; 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; } #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; } #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; } #endif /* CONFIG_COMPAT */ static int str_to_user(const char *str, unsigned int maxlen, void __user *p) { int len; if (!str)