Input: evdev - rearrange ioctl handling

Split ioctl handling into 3 separate sections: fixed-length ioctls,
variable-length ioctls and multi-number variable length handlers.
This reduces identation and makes the code a bit clearer.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 73 insertions, 68 deletions

diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 08f48c03eec4..c908c5f83645 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -492,13 +492,15 @@ static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
 }
 
 #define OLD_KEY_MAX     0x1ff
-static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user *p, int compat_mode)
+static int handle_eviocgbit(struct input_dev *dev,
+                            unsigned int type, unsigned int size,
+                            void __user *p, int compat_mode)
 {
         static unsigned long keymax_warn_time;
         unsigned long *bits;
         int len;
 
-        switch (_IOC_NR(cmd) & EV_MAX) {
+        switch (type) {
 
         case      0: bits = dev->evbit;  len = EV_MAX;  break;
         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
@@ -517,7 +519,7 @@ static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user
          * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len'
          * should be in bytes, not in bits.
          */
-        if ((_IOC_NR(cmd) & EV_MAX) == EV_KEY && _IOC_SIZE(cmd) == OLD_KEY_MAX) {
+        if (type == EV_KEY && size == OLD_KEY_MAX) {
                 len = OLD_KEY_MAX;
                 if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000))
                         printk(KERN_WARNING
@@ -528,7 +530,7 @@ static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user
                                 BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long));
         }
 
-        return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
+        return bits_to_user(bits, len, size, p, compat_mode);
 }
 #undef OLD_KEY_MAX
 
@@ -542,8 +544,10 @@ static long evdev_do_ioctl(struct file *file, unsigned int cmd,
         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:
@@ -610,101 +614,102 @@ static long evdev_do_ioctl(struct file *file, unsigned int cmd,
                         return evdev_grab(evdev, client);
                 else
                         return evdev_ungrab(evdev, client);
+        }
 
-        default:
+        size = _IOC_SIZE(cmd);
 
-                if (_IOC_TYPE(cmd) != 'E')
-                        return -EINVAL;
+        /* Now check variable-length commands */
+#define EVIOC_MASK_SIZE(nr)     ((nr) & ~(_IOC_SIZEMASK << _IOC_SIZESHIFT))
 
-                if (_IOC_DIR(cmd) == _IOC_READ) {
+        switch (EVIOC_MASK_SIZE(cmd)) {
 
-                        if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0)))
-                                return handle_eviocgbit(dev, cmd, p, compat_mode);
+        case EVIOCGKEY(0):
+                return bits_to_user(dev->key, KEY_MAX, size, 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);
+        case EVIOCGLED(0):
+                return bits_to_user(dev->led, LED_MAX, size, 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);
+        case EVIOCGSND(0):
+                return bits_to_user(dev->snd, SND_MAX, size, 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);
+        case EVIOCGSW(0):
+                return bits_to_user(dev->sw, SW_MAX, size, 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);
+        case EVIOCGNAME(0):
+                return str_to_user(dev->name, size, p);
 
-                        if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
-                                return str_to_user(dev->name, _IOC_SIZE(cmd), p);
+        case EVIOCGPHYS(0):
+                return str_to_user(dev->phys, size, p);
 
-                        if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
-                                return str_to_user(dev->phys, _IOC_SIZE(cmd), p);
+        case EVIOCGUNIQ(0):
+                return str_to_user(dev->uniq, size, p);
 
-                        if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
-                                return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);
+        case EVIOC_MASK_SIZE(EVIOCSFF):
+                if (input_ff_effect_from_user(p, size, &effect))
+                        return -EFAULT;
 
-                        if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
+                error = input_ff_upload(dev, &effect, file);
 
-                                t = _IOC_NR(cmd) & ABS_MAX;
-                                abs = dev->absinfo[t];
+                if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
+                        return -EFAULT;
 
-                                if (copy_to_user(p, &abs, min_t(size_t,
-                                                                _IOC_SIZE(cmd),
-                                                                sizeof(struct input_absinfo))))
-                                        return -EFAULT;
+                return error;
+        }
 
-                                return 0;
-                        }
+        /* Multi-number variable-length handlers */
+        if (_IOC_TYPE(cmd) != 'E')
+                return -EINVAL;
 
-                }
+        if (_IOC_DIR(cmd) == _IOC_READ) {
 
-                if (_IOC_DIR(cmd) == _IOC_WRITE) {
+                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) == _IOC_NR(EVIOCSFF)) {
+                if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
 
-                                if (input_ff_effect_from_user(p, _IOC_SIZE(cmd), &effect))
-                                        return -EFAULT;
+                        t = _IOC_NR(cmd) & ABS_MAX;
+                        abs = dev->absinfo[t];
 
-                                error = input_ff_upload(dev, &effect, file);
+                        if (copy_to_user(p, &abs, min_t(size_t,
+                                        size, sizeof(struct input_absinfo))))
+                                return -EFAULT;
 
-                                if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
-                                        return -EFAULT;
+                        return 0;
+                }
+        }
 
-                                return error;
-                        }
+        if (_IOC_DIR(cmd) == _IOC_READ) {
 
-                        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, min_t(size_t,
-                                                                  _IOC_SIZE(cmd),
-                                                                  sizeof(struct input_absinfo))))
-                                        return -EFAULT;
+                        if (copy_from_user(&abs, p, min_t(size_t,
+                                        size, sizeof(struct input_absinfo))))
+                                return -EFAULT;
 
-                                if (_IOC_SIZE(cmd) < sizeof(struct input_absinfo))
-                                        abs.resolution = 0;
+                        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;
+                        /* 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);
+                        /*
+                         * 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 0;
                 }
         }
+
         return -EINVAL;
 }