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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#define EVDEV_MINOR_BASE 64#define EVDEV_MINORS 32#define EVDEV_MIN_BUFFER_SIZE 64U#define EVDEV_BUF_PACKETS 8
#include <linux/poll.h>#include <linux/sched.h>#include <linux/slab.h>#include <linux/vmalloc.h>#include <linux/mm.h>#include <linux/module.h>#include <linux/init.h>#include <linux/input/mt.h>#include <linux/major.h>#include <linux/device.h>#include <linux/cdev.h>#include "input-compat.h"
struct evdev { int open; struct input_handle handle; struct evdev_client __rcu *grab; struct list_head client_list; spinlock_t client_lock; /* protects client_list */ struct mutex mutex; struct device dev; struct cdev cdev; bool exist;};
struct evdev_client { unsigned int head; unsigned int tail; unsigned int packet_head; /* [future] position of the first element of next packet */ spinlock_t buffer_lock; /* protects access to buffer, head and tail */ wait_queue_head_t wait; struct fasync_struct *fasync; struct evdev *evdev; struct list_head node; enum input_clock_type clk_type; bool revoked; unsigned long *evmasks[EV_CNT]; unsigned int bufsize; struct input_event buffer[] __counted_by(bufsize);};
static size_t evdev_get_mask_cnt(unsigned int type){ static const size_t counts[EV_CNT] = { /* EV_SYN==0 is EV_CNT, _not_ SYN_CNT, see EVIOCGBIT */ [EV_SYN] = EV_CNT, [EV_KEY] = KEY_CNT, [EV_REL] = REL_CNT, [EV_ABS] = ABS_CNT, [EV_MSC] = MSC_CNT, [EV_SW] = SW_CNT, [EV_LED] = LED_CNT, [EV_SND] = SND_CNT, [EV_FF] = FF_CNT, };
return (type < EV_CNT) ? counts[type] : 0;}
/* requires the buffer lock to be held */static bool __evdev_is_filtered(struct evdev_client *client, unsigned int type, unsigned int code){ unsigned long *mask; size_t cnt;
/* EV_SYN and unknown codes are never filtered */ if (type == EV_SYN || type >= EV_CNT) return false;
/* first test whether the type is filtered */ mask = client->evmasks[0]; if (mask && !test_bit(type, mask)) return true;
/* unknown values are never filtered */ cnt = evdev_get_mask_cnt(type); if (!cnt || code >= cnt) return false;
mask = client->evmasks[type]; return mask && !test_bit(code, mask);}
/* flush queued events of type @type, caller must hold client->buffer_lock */static void __evdev_flush_queue(struct evdev_client *client, unsigned int type){ unsigned int i, head, num; unsigned int mask = client->bufsize - 1; bool is_report; struct input_event *ev;
BUG_ON(type == EV_SYN);
head = client->tail; client->packet_head = client->tail;
/* init to 1 so a leading SYN_REPORT will not be dropped */ num = 1;
for (i = client->tail; i != client->head; i = (i + 1) & mask) { ev = &client->buffer[i]; is_report = ev->type == EV_SYN && ev->code == SYN_REPORT;
if (ev->type == type) { /* drop matched entry */ continue; } else if (is_report && !num) { /* drop empty SYN_REPORT groups */ continue; } else if (head != i) { /* move entry to fill the gap */ client->buffer[head] = *ev; }
num++; head = (head + 1) & mask;
if (is_report) { num = 0; client->packet_head = head; } }
client->head = head;}
static void __evdev_queue_syn_dropped(struct evdev_client *client){ ktime_t *ev_time = input_get_timestamp(client->evdev->handle.dev); struct timespec64 ts = ktime_to_timespec64(ev_time[client->clk_type]); struct input_event ev;
ev.input_event_sec = ts.tv_sec; ev.input_event_usec = ts.tv_nsec / NSEC_PER_USEC; ev.type = EV_SYN; ev.code = SYN_DROPPED; ev.value = 0;
client->buffer[client->head++] = ev; client->head &= client->bufsize - 1;
if (unlikely(client->head == client->tail)) { /* drop queue but keep our SYN_DROPPED event */ client->tail = (client->head - 1) & (client->bufsize - 1); client->packet_head = client->tail; }}
static void evdev_queue_syn_dropped(struct evdev_client *client){ unsigned long flags;
spin_lock_irqsave(&client->buffer_lock, flags); __evdev_queue_syn_dropped(client); spin_unlock_irqrestore(&client->buffer_lock, flags);}
static int evdev_set_clk_type(struct evdev_client *client, unsigned int clkid){ unsigned long flags; enum input_clock_type clk_type;
switch (clkid) {
case CLOCK_REALTIME: clk_type = INPUT_CLK_REAL; break; case CLOCK_MONOTONIC: clk_type = INPUT_CLK_MONO; break; case CLOCK_BOOTTIME: clk_type = INPUT_CLK_BOOT; break; default: return -EINVAL; }
if (client->clk_type != clk_type) { client->clk_type = clk_type;
/* * Flush pending events and queue SYN_DROPPED event, * but only if the queue is not empty. */ spin_lock_irqsave(&client->buffer_lock, flags);
if (client->head != client->tail) { client->packet_head = client->head = client->tail; __evdev_queue_syn_dropped(client); }
spin_unlock_irqrestore(&client->buffer_lock, flags); }
return 0;}
static void __pass_event(struct evdev_client *client, const struct input_event *event){ client->buffer[client->head++] = *event; client->head &= client->bufsize - 1;
if (unlikely(client->head == client->tail)) { /* * This effectively "drops" all unconsumed events, leaving * EV_SYN/SYN_DROPPED plus the newest event in the queue. */ client->tail = (client->head - 2) & (client->bufsize - 1);
client->buffer[client->tail] = (struct input_event) { .input_event_sec = event->input_event_sec, .input_event_usec = event->input_event_usec, .type = EV_SYN, .code = SYN_DROPPED, .value = 0, };
client->packet_head = client->tail; }
if (event->type == EV_SYN && event->code == SYN_REPORT) { client->packet_head = client->head; kill_fasync(&client->fasync, SIGIO, POLL_IN); }}
static void evdev_pass_values(struct evdev_client *client, const struct input_value *vals, unsigned int count, ktime_t *ev_time){ const struct input_value *v; struct input_event event; struct timespec64 ts; bool wakeup = false;
if (client->revoked) return;
ts = ktime_to_timespec64(ev_time[client->clk_type]); event.input_event_sec = ts.tv_sec; event.input_event_usec = ts.tv_nsec / NSEC_PER_USEC;
/* Interrupts are disabled, just acquire the lock. */ spin_lock(&client->buffer_lock);
for (v = vals; v != vals + count; v++) { if (__evdev_is_filtered(client, v->type, v->code)) continue;
if (v->type == EV_SYN && v->code == SYN_REPORT) { /* drop empty SYN_REPORT */ if (client->packet_head == client->head) continue;
wakeup = true; }
event.type = v->type; event.code = v->code; event.value = v->value; __pass_event(client, &event); }
spin_unlock(&client->buffer_lock);
if (wakeup) wake_up_interruptible_poll(&client->wait, EPOLLIN | EPOLLOUT | EPOLLRDNORM | EPOLLWRNORM);}
/* * Pass incoming events to all connected clients. */static unsigned int evdev_events(struct input_handle *handle, struct input_value *vals, unsigned int count){ struct evdev *evdev = handle->private; struct evdev_client *client; ktime_t *ev_time = input_get_timestamp(handle->dev);
rcu_read_lock();
client = rcu_dereference(evdev->grab);
if (client) evdev_pass_values(client, vals, count, ev_time); else list_for_each_entry_rcu(client, &evdev->client_list, node) evdev_pass_values(client, vals, count, ev_time);
rcu_read_unlock();
return count;}
static int evdev_fasync(int fd, struct file *file, int on){ struct evdev_client *client = file->private_data;
return fasync_helper(fd, file, on, &client->fasync);}
static void evdev_free(struct device *dev){ struct evdev *evdev = container_of(dev, struct evdev, dev);
input_put_device(evdev->handle.dev); kfree(evdev);}
/* * Grabs an event device (along with underlying input device). * This function is called with evdev->mutex taken. */static int evdev_grab(struct evdev *evdev, struct evdev_client *client){ int error;
if (evdev->grab) return -EBUSY;
error = input_grab_device(&evdev->handle); if (error) return error;
rcu_assign_pointer(evdev->grab, client);
return 0;}
static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client){ struct evdev_client *grab = rcu_dereference_protected(evdev->grab, lockdep_is_held(&evdev->mutex));
if (grab != client) return -EINVAL;
rcu_assign_pointer(evdev->grab, NULL); synchronize_rcu(); input_release_device(&evdev->handle);
return 0;}
static void evdev_attach_client(struct evdev *evdev, struct evdev_client *client){ spin_lock(&evdev->client_lock); list_add_tail_rcu(&client->node, &evdev->client_list); spin_unlock(&evdev->client_lock);}
static void evdev_detach_client(struct evdev *evdev, struct evdev_client *client){ spin_lock(&evdev->client_lock); list_del_rcu(&client->node); spin_unlock(&evdev->client_lock); synchronize_rcu();}
static int evdev_open_device(struct evdev *evdev){ int retval;
retval = mutex_lock_interruptible(&evdev->mutex); if (retval) return retval;
if (!evdev->exist) retval = -ENODEV; else if (!evdev->open++) { retval = input_open_device(&evdev->handle); if (retval) evdev->open--; }
mutex_unlock(&evdev->mutex); return retval;}
static void evdev_close_device(struct evdev *evdev){ mutex_lock(&evdev->mutex);
if (evdev->exist && !--evdev->open) input_close_device(&evdev->handle);
mutex_unlock(&evdev->mutex);}
/* * Wake up users waiting for IO so they can disconnect from * dead device. */static void evdev_hangup(struct evdev *evdev){ struct evdev_client *client;
spin_lock(&evdev->client_lock); list_for_each_entry(client, &evdev->client_list, node) { kill_fasync(&client->fasync, SIGIO, POLL_HUP); wake_up_interruptible_poll(&client->wait, EPOLLHUP | EPOLLERR); } spin_unlock(&evdev->client_lock);}
static int evdev_release(struct inode *inode, struct file *file){ struct evdev_client *client = file->private_data; struct evdev *evdev = client->evdev; unsigned int i;
mutex_lock(&evdev->mutex);
if (evdev->exist && !client->revoked) input_flush_device(&evdev->handle, file);
evdev_ungrab(evdev, client); mutex_unlock(&evdev->mutex);
evdev_detach_client(evdev, client);
for (i = 0; i < EV_CNT; ++i) bitmap_free(client->evmasks[i]);
kvfree(client);
evdev_close_device(evdev);
return 0;}
static unsigned int evdev_compute_buffer_size(struct input_dev *dev){ unsigned int n_events = max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS, EVDEV_MIN_BUFFER_SIZE);
return roundup_pow_of_two(n_events);}
static int evdev_open(struct inode *inode, struct file *file){ struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev); unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev); struct evdev_client *client; int error;
client = kvzalloc_flex(*client, buffer, bufsize); if (!client) return -ENOMEM;
init_waitqueue_head(&client->wait); client->bufsize = bufsize; spin_lock_init(&client->buffer_lock); client->evdev = evdev; evdev_attach_client(evdev, client);
error = evdev_open_device(evdev); if (error) goto err_free_client;
file->private_data = client; stream_open(inode, file);
return 0;
err_free_client: evdev_detach_client(evdev, client); kvfree(client); return error;}
static ssize_t evdev_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos){ struct evdev_client *client = file->private_data; struct evdev *evdev = client->evdev; struct input_event event; int retval = 0;
/* * Limit amount of data we inject into the input subsystem so that * we do not hold evdev->mutex for too long. 4096 bytes corresponds * to 170 input events. */ count = min(count, 4096);
if (count != 0 && count < input_event_size()) return -EINVAL;
retval = mutex_lock_interruptible(&evdev->mutex); if (retval) return retval;
if (!evdev->exist || client->revoked) { retval = -ENODEV; goto out; }
while (retval + input_event_size() <= count) {
if (input_event_from_user(buffer + retval, &event)) { retval = -EFAULT; goto out; } retval += input_event_size();
input_inject_event(&evdev->handle, event.type, event.code, event.value); cond_resched(); }
out: mutex_unlock(&evdev->mutex); return retval;}
static int evdev_fetch_next_event(struct evdev_client *client, struct input_event *event){ int have_event;
spin_lock_irq(&client->buffer_lock);
have_event = client->packet_head != client->tail; if (have_event) { *event = client->buffer[client->tail++]; client->tail &= client->bufsize - 1; }
spin_unlock_irq(&client->buffer_lock);
return have_event;}
static ssize_t evdev_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos){ struct evdev_client *client = file->private_data; struct evdev *evdev = client->evdev; struct input_event event; size_t read = 0; int error;
if (count != 0 && count < input_event_size()) return -EINVAL;
for (;;) { if (!evdev->exist || client->revoked) return -ENODEV;
if (client->packet_head == client->tail && (file->f_flags & O_NONBLOCK)) return -EAGAIN;
/* * count == 0 is special - no IO is done but we check * for error conditions (see above). */ if (count == 0) break;
while (read + input_event_size() <= count && evdev_fetch_next_event(client, &event)) {
if (input_event_to_user(buffer + read, &event)) return -EFAULT;
read += input_event_size(); }
if (read) break;
if (!(file->f_flags & O_NONBLOCK)) { error = wait_event_interruptible(client->wait, client->packet_head != client->tail || !evdev->exist || client->revoked); if (error) return error; } }
return read;}
/* No kernel lock - fine */static __poll_t evdev_poll(struct file *file, poll_table *wait){ struct evdev_client *client = file->private_data; struct evdev *evdev = client->evdev; __poll_t mask;
poll_wait(file, &client->wait, wait);
if (evdev->exist && !client->revoked) mask = EPOLLOUT | EPOLLWRNORM; else mask = EPOLLHUP | EPOLLERR;
if (client->packet_head != client->tail) mask |= EPOLLIN | EPOLLRDNORM;
return mask;}
#ifdef CONFIG_COMPAT
#define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)#define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
#ifdef __BIG_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;}
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_COMPATstatic long evdev_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg){ return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);}#endif
static const struct file_operations evdev_fops = { .owner = THIS_MODULE, .read = evdev_read, .write = evdev_write, .poll = evdev_poll, .open = evdev_open, .release = evdev_release, .unlocked_ioctl = evdev_ioctl,#ifdef CONFIG_COMPAT .compat_ioctl = evdev_ioctl_compat,#endif .fasync = evdev_fasync,};
/* * Mark device non-existent. This disables writes, ioctls and * prevents new users from opening the device. Already posted * blocking reads will stay, however new ones will fail. */static void evdev_mark_dead(struct evdev *evdev){ mutex_lock(&evdev->mutex); evdev->exist = false; mutex_unlock(&evdev->mutex);}
static void evdev_cleanup(struct evdev *evdev){ struct input_handle *handle = &evdev->handle;
evdev_mark_dead(evdev); evdev_hangup(evdev);
/* evdev is marked dead so no one else accesses evdev->open */ if (evdev->open) { input_flush_device(handle, NULL); input_close_device(handle); }}
/* * Create new evdev device. Note that input core serializes calls * to connect and disconnect. */static int evdev_connect(struct input_handler *handler, struct input_dev *dev, const struct input_device_id *id){ struct evdev *evdev; int minor; int dev_no; int error;
minor = input_get_new_minor(EVDEV_MINOR_BASE, EVDEV_MINORS, true); if (minor < 0) { error = minor; pr_err("failed to reserve new minor: %d\n", error); return error; }
evdev = kzalloc_obj(struct evdev); 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[] = { { /* Matches all devices */ .flags = INPUT_DEVICE_ID_MATCH_EVBIT, .evbit = { BIT_MASK(EV_SYN) }, }, { } /* Terminating zero entry */};
MODULE_DEVICE_TABLE(input, evdev_ids);
static struct input_handler evdev_handler = { .events = evdev_events, .connect = evdev_connect, .disconnect = evdev_disconnect, .legacy_minors = true, .minor = EVDEV_MINOR_BASE, .name = "evdev", .id_table = evdev_ids,};
static int __init evdev_init(void){ return input_register_handler(&evdev_handler);}
static void __exit evdev_exit(void){ input_unregister_handler(&evdev_handler);}
module_init(evdev_init);module_exit(evdev_exit);
MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");MODULE_DESCRIPTION("Input driver event char devices");MODULE_LICENSE("GPL");