diff options
| -rw-r--r-- | drivers/input/evdev.c | 713 |
1 files changed, 473 insertions, 240 deletions
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c index f1c3d6cebd58..4eb2805b7173 100644 --- a/drivers/input/evdev.c +++ b/drivers/input/evdev.c @@ -30,6 +30,8 @@ struct evdev { wait_queue_head_t wait; struct evdev_client *grab; struct list_head client_list; + spinlock_t client_lock; /* protects client_list */ + struct mutex mutex; struct device dev; }; @@ -37,39 +39,53 @@ struct evdev_client { struct input_event buffer[EVDEV_BUFFER_SIZE]; int head; int tail; + spinlock_t buffer_lock; /* protects access to buffer, head and tail */ struct fasync_struct *fasync; struct evdev *evdev; struct list_head node; }; static struct evdev *evdev_table[EVDEV_MINORS]; +static DEFINE_MUTEX(evdev_table_mutex); -static void evdev_event(struct input_handle *handle, unsigned int type, unsigned int code, int value) +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 &= EVDEV_BUFFER_SIZE - 1; + spin_unlock(&client->buffer_lock); + + kill_fasync(&client->fasync, SIGIO, POLL_IN); +} + +/* + * Pass incoming event to all connected clients. Note that we are + * caleld under a spinlock with interrupts off so we don't need + * to use rcu_read_lock() here. Writers will be using syncronize_sched() + * instead of synchrnoize_rcu(). + */ +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; - if (evdev->grab) { - client = evdev->grab; - - do_gettimeofday(&client->buffer[client->head].time); - client->buffer[client->head].type = type; - client->buffer[client->head].code = code; - client->buffer[client->head].value = value; - client->head = (client->head + 1) & (EVDEV_BUFFER_SIZE - 1); - - kill_fasync(&client->fasync, SIGIO, POLL_IN); - } else - list_for_each_entry(client, &evdev->client_list, node) { - - do_gettimeofday(&client->buffer[client->head].time); - client->buffer[client->head].type = type; - client->buffer[client->head].code = code; - client->buffer[client->head].value = value; - client->head = (client->head + 1) & (EVDEV_BUFFER_SIZE - 1); + do_gettimeofday(&event.time); + event.type = type; + event.code = code; + event.value = value; - kill_fasync(&client->fasync, SIGIO, POLL_IN); - } + 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); wake_up_interruptible(&evdev->wait); } @@ -88,38 +104,142 @@ 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) - return -ENODEV; + retval = -ENODEV; + else + retval = input_flush_device(&evdev->handle, file); - return 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); - evdev_table[evdev->minor] = NULL; 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); + /* + * We don't use synchronize_rcu() here because read-side + * critical section is protected by a spinlock instead + * of rcu_read_lock(). + */ + synchronize_sched(); + + 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_sched(); + 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); + synchronize_sched(); +} + +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_sched(); +} + +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); + + 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; - if (evdev->grab == client) { - input_release_device(&evdev->handle); - evdev->grab = NULL; - } + mutex_lock(&evdev->mutex); + if (evdev->grab == client) + evdev_ungrab(evdev, client); + mutex_unlock(&evdev->mutex); evdev_fasync(-1, file, 0); - list_del(&client->node); + evdev_detach_client(evdev, client); kfree(client); - if (!--evdev->open && evdev->exist) - input_close_device(&evdev->handle); - + evdev_close_device(evdev); put_device(&evdev->dev); return 0; @@ -127,41 +247,44 @@ static int evdev_release(struct inode *inode, struct file *file) static int evdev_open(struct inode *inode, struct file *file) { - struct evdev_client *client; struct evdev *evdev; + struct evdev_client *client; int i = iminor(inode) - EVDEV_MINOR_BASE; 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 || !evdev->exist) + if (!evdev) return -ENODEV; - get_device(&evdev->dev); - client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL); if (!client) { error = -ENOMEM; goto err_put_evdev; } + spin_lock_init(&client->buffer_lock); client->evdev = evdev; - list_add_tail(&client->node, &evdev->client_list); + evdev_attach_client(evdev, client); - if (!evdev->open++ && evdev->exist) { - error = input_open_device(&evdev->handle); - if (error) - goto err_free_client; - } + error = evdev_open_device(evdev); + if (error) + goto err_free_client; file->private_data = client; return 0; err_free_client: - list_del(&client->node); + evdev_detach_client(evdev, client); kfree(client); err_put_evdev: put_device(&evdev->dev); @@ -197,12 +320,14 @@ static inline size_t evdev_event_size(void) sizeof(struct input_event_compat) : sizeof(struct input_event); } -static int evdev_event_from_user(const char __user *buffer, struct input_event *event) +static int evdev_event_from_user(const char __user *buffer, + struct input_event *event) { if (COMPAT_TEST) { struct input_event_compat compat_event; - if (copy_from_user(&compat_event, buffer, sizeof(struct input_event_compat))) + if (copy_from_user(&compat_event, buffer, + sizeof(struct input_event_compat))) return -EFAULT; event->time.tv_sec = compat_event.time.tv_sec; @@ -219,7 +344,8 @@ static int evdev_event_from_user(const char __user *buffer, struct input_event * return 0; } -static int evdev_event_to_user(char __user *buffer, const struct input_event *event) +static int evdev_event_to_user(char __user *buffer, + const struct input_event *event) { if (COMPAT_TEST) { struct input_event_compat compat_event; @@ -230,7 +356,8 @@ static int evdev_event_to_user(char __user *buffer, const struct input_event *ev compat_event.code = event->code; compat_event.value = event->value; - if (copy_to_user(buffer, &compat_event, sizeof(struct input_event_compat))) + if (copy_to_user(buffer, &compat_event, + sizeof(struct input_event_compat))) return -EFAULT; } else { @@ -248,7 +375,8 @@ static inline size_t evdev_event_size(void) return sizeof(struct input_event); } -static int evdev_event_from_user(const char __user *buffer, struct input_event *event) +static int evdev_event_from_user(const char __user *buffer, + struct input_event *event) { if (copy_from_user(event, buffer, sizeof(struct input_event))) return -EFAULT; @@ -256,7 +384,8 @@ static int evdev_event_from_user(const char __user *buffer, struct input_event * return 0; } -static int evdev_event_to_user(char __user *buffer, const struct input_event *event) +static int evdev_event_to_user(char __user *buffer, + const struct input_event *event) { if (copy_to_user(buffer, event, sizeof(struct input_event))) return -EFAULT; @@ -266,37 +395,71 @@ static int evdev_event_to_user(char __user *buffer, const struct input_event *ev #endif /* CONFIG_COMPAT */ -static ssize_t evdev_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) +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; + int retval; - if (!evdev->exist) - return -ENODEV; + retval = mutex_lock_interruptible(&evdev->mutex); + if (retval) + return retval; + + if (!evdev->exist) { + retval = -ENODEV; + goto out; + } while (retval < count) { - if (evdev_event_from_user(buffer + retval, &event)) - return -EFAULT; - input_inject_event(&evdev->handle, event.type, event.code, event.value); + if (evdev_event_from_user(buffer + retval, &event)) { + retval = -EFAULT; + goto out; + } + + input_inject_event(&evdev->handle, + event.type, event.code, event.value); retval += evdev_event_size(); } + out: + mutex_unlock(&evdev->mutex); return retval; } -static ssize_t evdev_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) +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 &= EVDEV_BUFFER_SIZE - 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 < evdev_event_size()) return -EINVAL; - if (client->head == client->tail && evdev->exist && (file->f_flags & O_NONBLOCK)) + if (client->head == client->tail && evdev->exist && + (file->f_flags & O_NONBLOCK)) return -EAGAIN; retval = wait_event_interruptible(evdev->wait, @@ -307,14 +470,12 @@ static ssize_t evdev_read(struct file *file, char __user *buffer, size_t count, if (!evdev->exist) return -ENODEV; - while (client->head != client->tail && retval + evdev_event_size() <= count) { - - struct input_event *event = (struct input_event *) client->buffer + client->tail; + while (retval + evdev_event_size() <= count && + evdev_fetch_next_event(client, &event)) { - if (evdev_event_to_user(buffer + retval, event)) + if (evdev_event_to_user(buffer + retval, &event)) return -EFAULT; - client->tail = (client->tail + 1) & (EVDEV_BUFFER_SIZE - 1); retval += evdev_event_size(); } @@ -409,8 +570,8 @@ static int str_to_user(const char *str, unsigned int maxlen, void __user *p) return copy_to_user(p, str, len) ? -EFAULT : len; } -static long evdev_ioctl_handler(struct file *file, unsigned int cmd, - void __user *p, int compat_mode) +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; @@ -421,215 +582,289 @@ static long evdev_ioctl_handler(struct file *file, unsigned int cmd, int i, t, u, v; int error; - if (!evdev->exist) - return -ENODEV; - switch (cmd) { - case EVIOCGVERSION: - return put_user(EV_VERSION, ip); + 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 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 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; + 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); + input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u); + input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v); - return 0; + return 0; - case EVIOCGKEYCODE: - if (get_user(t, ip)) - return -EFAULT; + case EVIOCGKEYCODE: + if (get_user(t, ip)) + return -EFAULT; - error = dev->getkeycode(dev, t, &v); - if (error) - return error; + error = dev->getkeycode(dev, t, &v); + if (error) + return error; - if (put_user(v, ip + 1)) - return -EFAULT; + if (put_user(v, ip + 1)) + return -EFAULT; - return 0; + return 0; - case EVIOCSKEYCODE: - if (get_user(t, ip) || get_user(v, ip + 1)) - return -EFAULT; + case EVIOCSKEYCODE: + if (get_user(t, ip) || get_user(v, ip + 1)) + return -EFAULT; - return dev->setkeycode(dev, t, v); + return dev->setkeycode(dev, t, v); - case EVIOCSFF: - if (copy_from_user(&effect, p, sizeof(effect))) - return -EFAULT; + case EVIOCSFF: + if (copy_from_user(&effect, p, sizeof(effect))) + return -EFAULT; - error = input_ff_upload(dev, &effect, file); + error = input_ff_upload(dev, &effect, file); - if (put_user(effect.id, &(((struct ff_effect __user *)p)->id))) - return -EFAULT; + if (put_user(effect.id, &(((struct ff_effect __user *)p)->id))) + return -EFAULT; - return error; + return error; - case EVIOCRMFF: - return input_ff_erase(dev, (int)(unsigned long) p, file); + 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) { - if (evdev->grab) - return -EBUSY; - if (input_grab_device(&evdev->handle)) - return -EBUSY; - evdev->grab = client; - return 0; - } else { - if (evdev->grab != client) - return -EINVAL; - input_release_device(&evdev->handle); - evdev->grab = NULL; - return 0; - } + 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); - default: + default: - if (_IOC_TYPE(cmd) != 'E') - return -EINVAL; + if (_IOC_TYPE(cmd) != 'E') + return -EINVAL; - if (_IOC_DIR(cmd) == _IOC_READ) { + if (_IOC_DIR(cmd) == _IOC_READ) { - if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0,0))) { + if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0))) { - unsigned long *bits; - int len; + unsigned long *bits; + int len; - switch (_IOC_NR(cmd) & EV_MAX) { - 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, _IOC_SIZE(cmd), p, compat_mode); - } + switch (_IOC_NR(cmd) & EV_MAX) { - if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0))) - return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd), - p, compat_mode); + 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, _IOC_SIZE(cmd), p, compat_mode); + } - if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0))) - return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd), - p, compat_mode); + if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0))) + return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd), + p, compat_mode); - if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0))) - return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd), - p, compat_mode); + if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0))) + return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd), + p, compat_mode); - if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0))) - return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd), - p, compat_mode); + if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0))) + return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd), + p, compat_mode); - if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0))) - return str_to_user(dev->name, _IOC_SIZE(cmd), p); + if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0))) + return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd), + p, compat_mode); - if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0))) - return str_to_user(dev->phys, _IOC_SIZE(cmd), p); + if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0))) + return str_to_user(dev->name, _IOC_SIZE(cmd), p); - if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0))) - return str_to_user(dev->uniq, _IOC_SIZE(cmd), p); + if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0))) + return str_to_user(dev->phys, _IOC_SIZE(cmd), p); - if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) { + if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0))) + return str_to_user(dev->uniq, _IOC_SIZE(cmd), p); - t = _IOC_NR(cmd) & ABS_MAX; + if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) { - abs.value = dev->abs[t]; - abs.minimum = dev->absmin[t]; - abs.maximum = dev->absmax[t]; - abs.fuzz = dev->absfuzz[t]; - abs.flat = dev->absflat[t]; + t = _IOC_NR(cmd) & ABS_MAX; - if (copy_to_user(p, &abs, sizeof(struct input_absinfo))) - return -EFAULT; + abs.value = dev->abs[t]; + abs.minimum = dev->absmin[t]; + abs.maximum = dev->absmax[t]; + abs.fuzz = dev->absfuzz[t]; + abs.flat = dev->absflat[t]; - return 0; - } + if (copy_to_user(p, &abs, sizeof(struct input_absinfo))) + return -EFAULT; + return 0; } - if (_IOC_DIR(cmd) == _IOC_WRITE) { + } + + if (_IOC_DIR(cmd) == _IOC_WRITE) { - if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) { + if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) { - t = _IOC_NR(cmd) & ABS_MAX; + t = _IOC_NR(cmd) & ABS_MAX; - if (copy_from_user(&abs, p, sizeof(struct input_absinfo))) - return -EFAULT; + if (copy_from_user(&abs, p, + sizeof(struct input_absinfo))) + return -EFAULT; - dev->abs[t] = abs.value; - dev->absmin[t] = abs.minimum; - dev->absmax[t] = abs.maximum; - dev->absfuzz[t] = abs.fuzz; - dev->absflat[t] = abs.flat; + /* + * Take event lock to ensure that we are not + * changing device parameters in the middle + * of event. + */ + spin_lock_irq(&dev->event_lock); - return 0; - } + dev->abs[t] = abs.value; + dev->absmin[t] = abs.minimum; + dev->absmax[t] = abs.maximum; + dev->absfuzz[t] = abs.fuzz; + dev->absflat[t] = abs.flat; + + 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) { + 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) +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, + .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, + .compat_ioctl = evdev_ioctl_compat, #endif - .fasync = evdev_fasync, - .flush = evdev_flush + .fasync = evdev_fasync, + .flush = evdev_flush }; +static int evdev_install_chrdev(struct evdev *evdev) +{ + /* + * No need to do any locking here as calls to connect and + * disconnect are serialized by the input core + */ + evdev_table[evdev->minor] = evdev; + return 0; +} + +static void evdev_remove_chrdev(struct evdev *evdev) +{ + /* + * Lock evdev table to prevent race with evdev_open() + */ + mutex_lock(&evdev_table_mutex); + evdev_table[evdev->minor] = NULL; + mutex_unlock(&evdev_table_mutex); +} + +/* + * 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 = 0; + 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_remove_chrdev(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 so we don't need to lock evdev_table here. + */ static int evdev_connect(struct input_handler *handler, struct input_dev *dev, const struct input_device_id *id) { @@ -637,7 +872,10 @@ static int evdev_connect(struct input_handler *handler, struct input_dev *dev, int minor; int error; - for (minor = 0; minor < EVDEV_MINORS && evdev_table[minor]; minor++); + for (minor = 0; minor < EVDEV_MINORS; minor++) + if (!evdev_table[minor]) + break; + if (minor == EVDEV_MINORS) { printk(KERN_ERR "evdev: no more free evdev devices\n"); return -ENFILE; @@ -648,38 +886,44 @@ static int evdev_connect(struct input_handler *handler, struct input_dev *dev, return -ENOMEM; INIT_LIST_HEAD(&evdev->client_list); + spin_lock_init(&evdev->client_lock); + mutex_init(&evdev->mutex); init_waitqueue_head(&evdev->wait); + snprintf(evdev->name, sizeof(evdev->name), "event%d", minor); evdev->exist = 1; evdev->minor = minor; + evdev->handle.dev = dev; evdev->handle.name = evdev->name; evdev->handle.handler = handler; evdev->handle.private = evdev; - snprintf(evdev->name, sizeof(evdev->name), "event%d", minor); - snprintf(evdev->dev.bus_id, sizeof(evdev->dev.bus_id), - "event%d", minor); + strlcpy(evdev->dev.bus_id, evdev->name, sizeof(evdev->dev.bus_id)); + evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor); evdev->dev.class = &input_class; evdev->dev.parent = &dev->dev; - evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor); evdev->dev.release = evdev_free; device_initialize(&evdev->dev); - evdev_table[minor] = evdev; - - error = device_add(&evdev->dev); + error = input_register_handle(&evdev->handle); if (error) goto err_free_evdev; - error = input_register_handle(&evdev->handle); + error = evdev_install_chrdev(evdev); + if (error) + goto err_unregister_handle; + + error = device_add(&evdev->dev); if (error) - goto err_delete_evdev; + goto err_cleanup_evdev; return 0; - err_delete_evdev: - device_del(&evdev->dev); + err_cleanup_evdev: + evdev_cleanup(evdev); + err_unregister_handle: + input_unregister_handle(&evdev->handle); err_free_evdev: put_device(&evdev->dev); return error; @@ -688,21 +932,10 @@ static int evdev_connect(struct input_handler *handler, struct input_dev *dev, static void evdev_disconnect(struct input_handle *handle) { struct evdev *evdev = handle->private; - struct evdev_client *client; - input_unregister_handle(handle); device_del(&evdev->dev); - - evdev->exist = 0; - - if (evdev->open) { - input_flush_device(handle, NULL); - input_close_device(handle); - list_for_each_entry(client, &evdev->client_list, node) - kill_fasync(&client->fasync, SIGIO, POLL_HUP); - wake_up_interruptible(&evdev->wait); - } - + evdev_cleanup(evdev); + input_unregister_handle(handle); put_device(&evdev->dev); } @@ -714,13 +947,13 @@ static const struct input_device_id evdev_ids[] = { MODULE_DEVICE_TABLE(input, evdev_ids); static struct input_handler evdev_handler = { - .event = evdev_event, - .connect = evdev_connect, - .disconnect = evdev_disconnect, - .fops = &evdev_fops, - .minor = EVDEV_MINOR_BASE, - .name = "evdev", - .id_table = evdev_ids, + .event = evdev_event, + .connect = evdev_connect, + .disconnect = evdev_disconnect, + .fops = &evdev_fops, + .minor = EVDEV_MINOR_BASE, + .name = "evdev", + .id_table = evdev_ids, }; static int __init evdev_init(void) |