Input: refactor evdev 32bit compat to be shareable with uinput

Currently, evdev has working 32bit compatibility and uinput does not. uinput
needs the input_event code that evdev uses, so let's refactor it so it can
be shared.

[dtor@mail.ru: add fix for force feedback compat issues]
Signed-off-by: Philip Langdale <philipl@overt.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 145 insertions, 27 deletions

diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c
index 223d56d5555b..46b7caeb2817 100644
--- a/drivers/input/misc/uinput.c
+++ b/drivers/input/misc/uinput.c
@@ -37,6 +37,7 @@
 #include <linux/fs.h>
 #include <linux/miscdevice.h>
 #include <linux/uinput.h>
+#include "../input-compat.h"
 
 static int uinput_dev_event(struct input_dev *dev, unsigned int type, unsigned int code, int value)
 {
@@ -78,6 +79,7 @@ static struct uinput_request* uinput_request_find(struct uinput_device *udev, in
         /* Find an input request, by ID. Returns NULL if the ID isn't valid. */
         if (id >= UINPUT_NUM_REQUESTS || id < 0)
                 return NULL;
+
         return udev->requests[id];
 }
 
@@ -127,6 +129,17 @@ static int uinput_dev_upload_effect(struct input_dev *dev, struct ff_effect *eff
         struct uinput_request request;
         int retval;
 
+        /*
+         * uinput driver does not currently support periodic effects with
+         * custom waveform since it does not have a way to pass buffer of
+         * samples (custom_data) to userspace. If ever there is a device
+         * supporting custom waveforms we would need to define an additional
+         * ioctl (UI_UPLOAD_SAMPLES) but for now we just bail out.
+         */
+        if (effect->type == FF_PERIODIC &&
+                        effect->u.periodic.waveform == FF_CUSTOM)
+                return -EINVAL;
+
         request.id = -1;
         init_completion(&request.done);
         request.code = UI_FF_UPLOAD;
@@ -353,15 +366,15 @@ static inline ssize_t uinput_inject_event(struct uinput_device *udev, const char
 {
         struct input_event ev;
 
-        if (count != sizeof(struct input_event))
+        if (count < input_event_size())
                 return -EINVAL;
 
-        if (copy_from_user(&ev, buffer, sizeof(struct input_event)))
+        if (input_event_from_user(buffer, &ev))
                 return -EFAULT;
 
         input_event(udev->dev, ev.type, ev.code, ev.value);
 
-        return sizeof(struct input_event);
+        return input_event_size();
 }
 
 static ssize_t uinput_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
@@ -407,13 +420,13 @@ static ssize_t uinput_read(struct file *file, char __user *buffer, size_t count,
                 goto out;
         }
 
-        while (udev->head != udev->tail && retval + sizeof(struct input_event) <= count) {
-                if (copy_to_user(buffer + retval, &udev->buff[udev->tail], sizeof(struct input_event))) {
+        while (udev->head != udev->tail && retval + input_event_size() <= count) {
+                if (input_event_to_user(buffer + retval, &udev->buff[udev->tail])) {
                         retval = -EFAULT;
                         goto out;
                 }
                 udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
-                retval += sizeof(struct input_event);
+                retval += input_event_size();
         }
 
  out:
@@ -444,6 +457,93 @@ static int uinput_release(struct inode *inode, struct file *file)
         return 0;
 }
 
+#ifdef CONFIG_COMPAT
+struct uinput_ff_upload_compat {
+        int                     request_id;
+        int                     retval;
+        struct ff_effect_compat effect;
+        struct ff_effect_compat old;
+};
+
+static int uinput_ff_upload_to_user(char __user *buffer,
+                                    const struct uinput_ff_upload *ff_up)
+{
+        if (INPUT_COMPAT_TEST) {
+                struct uinput_ff_upload_compat ff_up_compat;
+
+                ff_up_compat.request_id = ff_up->request_id;
+                ff_up_compat.retval = ff_up->retval;
+                /*
+                 * It so happens that the pointer that gives us the trouble
+                 * is the last field in the structure. Since we don't support
+                 * custom waveforms in uinput anyway we can just copy the whole
+                 * thing (to the compat size) and ignore the pointer.
+                 */
+                memcpy(&ff_up_compat.effect, &ff_up->effect,
+                        sizeof(struct ff_effect_compat));
+                memcpy(&ff_up_compat.old, &ff_up->old,
+                        sizeof(struct ff_effect_compat));
+
+                if (copy_to_user(buffer, &ff_up_compat,
+                                 sizeof(struct uinput_ff_upload_compat)))
+                        return -EFAULT;
+        } else {
+                if (copy_to_user(buffer, ff_up,
+                                 sizeof(struct uinput_ff_upload)))
+                        return -EFAULT;
+        }
+
+        return 0;
+}
+
+static int uinput_ff_upload_from_user(const char __user *buffer,
+                                      struct uinput_ff_upload *ff_up)
+{
+        if (INPUT_COMPAT_TEST) {
+                struct uinput_ff_upload_compat ff_up_compat;
+
+                if (copy_from_user(&ff_up_compat, buffer,
+                                   sizeof(struct uinput_ff_upload_compat)))
+                        return -EFAULT;
+
+                ff_up->request_id = ff_up_compat.request_id;
+                ff_up->retval = ff_up_compat.retval;
+                memcpy(&ff_up->effect, &ff_up_compat.effect,
+                        sizeof(struct ff_effect_compat));
+                memcpy(&ff_up->old, &ff_up_compat.old,
+                        sizeof(struct ff_effect_compat));
+
+        } else {
+                if (copy_from_user(ff_up, buffer,
+                                   sizeof(struct uinput_ff_upload)))
+                        return -EFAULT;
+        }
+
+        return 0;
+}
+
+#else
+
+static int uinput_ff_upload_to_user(char __user *buffer,
+                                    const struct uinput_ff_upload *ff_up)
+{
+        if (copy_to_user(buffer, ff_up, sizeof(struct uinput_ff_upload)))
+                return -EFAULT;
+
+        return 0;
+}
+
+static int uinput_ff_upload_from_user(const char __user *buffer,
+                                      struct uinput_ff_upload *ff_up)
+{
+        if (copy_from_user(ff_up, buffer, sizeof(struct uinput_ff_upload)))
+                return -EFAULT;
+
+        return 0;
+}
+
+#endif
+
 #define uinput_set_bit(_arg, _bit, _max)                \
 ({                                                      \
         int __ret = 0;                                  \
@@ -455,19 +555,17 @@ static int uinput_release(struct inode *inode, struct file *file)
         __ret;                                          \
 })
 
-static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+static long uinput_ioctl_handler(struct file *file, unsigned int cmd,
+                                 unsigned long arg, void __user *p)
 {
         int                     retval;
-        struct uinput_device    *udev;
-        void __user             *p = (void __user *)arg;
+        struct uinput_device    *udev = file->private_data;
         struct uinput_ff_upload ff_up;
         struct uinput_ff_erase  ff_erase;
         struct uinput_request   *req;
         int                     length;
         char                    *phys;
 
-        udev = file->private_data;
-
         retval = mutex_lock_interruptible(&udev->mutex);
         if (retval)
                 return retval;
@@ -549,26 +647,24 @@ static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
                         break;
 
                 case UI_BEGIN_FF_UPLOAD:
-                        if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
-                                retval = -EFAULT;
+                        retval = uinput_ff_upload_from_user(p, &ff_up);
+                        if (retval)
                                 break;
-                        }
+
                         req = uinput_request_find(udev, ff_up.request_id);
-                        if (!(req && req->code == UI_FF_UPLOAD && req->u.upload.effect)) {
+                        if (!req || req->code != UI_FF_UPLOAD || !req->u.upload.effect) {
                                 retval = -EINVAL;
                                 break;
                         }
+
                         ff_up.retval = 0;
-                        memcpy(&ff_up.effect, req->u.upload.effect, sizeof(struct ff_effect));
+                        ff_up.effect = *req->u.upload.effect;
                         if (req->u.upload.old)
-                                memcpy(&ff_up.old, req->u.upload.old, sizeof(struct ff_effect));
+                                ff_up.old = *req->u.upload.old;
                         else
                                 memset(&ff_up.old, 0, sizeof(struct ff_effect));
 
-                        if (copy_to_user(p, &ff_up, sizeof(ff_up))) {
-                                retval = -EFAULT;
-                                break;
-                        }
+                        retval = uinput_ff_upload_to_user(p, &ff_up);
                         break;
 
                 case UI_BEGIN_FF_ERASE:
@@ -576,29 +672,34 @@ static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
                                 retval = -EFAULT;
                                 break;
                         }
+
                         req = uinput_request_find(udev, ff_erase.request_id);
-                        if (!(req && req->code == UI_FF_ERASE)) {
+                        if (!req || req->code != UI_FF_ERASE) {
                                 retval = -EINVAL;
                                 break;
                         }
+
                         ff_erase.retval = 0;
                         ff_erase.effect_id = req->u.effect_id;
                         if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
                                 retval = -EFAULT;
                                 break;
                         }
+
                         break;
 
                 case UI_END_FF_UPLOAD:
-                        if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
-                                retval = -EFAULT;
+                        retval = uinput_ff_upload_from_user(p, &ff_up);
+                        if (retval)
                                 break;
-                        }
+
                         req = uinput_request_find(udev, ff_up.request_id);
-                        if (!(req && req->code == UI_FF_UPLOAD && req->u.upload.effect)) {
+                        if (!req || req->code != UI_FF_UPLOAD ||
+                            !req->u.upload.effect) {
                                 retval = -EINVAL;
                                 break;
                         }
+
                         req->retval = ff_up.retval;
                         uinput_request_done(udev, req);
                         break;
@@ -608,11 +709,13 @@ static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
                                 retval = -EFAULT;
                                 break;
                         }
+
                         req = uinput_request_find(udev, ff_erase.request_id);
-                        if (!(req && req->code == UI_FF_ERASE)) {
+                        if (!req || req->code != UI_FF_ERASE) {
                                 retval = -EINVAL;
                                 break;
                         }
+
                         req->retval = ff_erase.retval;
                         uinput_request_done(udev, req);
                         break;
@@ -626,6 +729,18 @@ static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
         return retval;
 }
 
+static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+        return uinput_ioctl_handler(file, cmd, arg, (void __user *)arg);
+}
+
+#ifdef CONFIG_COMPAT
+static long uinput_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+        return uinput_ioctl_handler(file, cmd, arg, compat_ptr(arg));
+}
+#endif
+
 static const struct file_operations uinput_fops = {
         .owner          = THIS_MODULE,
         .open           = uinput_open,
@@ -634,6 +749,9 @@ static const struct file_operations uinput_fops = {
         .write          = uinput_write,
         .poll           = uinput_poll,
         .unlocked_ioctl = uinput_ioctl,
+#ifdef CONFIG_COMPAT
+        .compat_ioctl   = uinput_compat_ioctl,
+#endif
 };
 
 static struct miscdevice uinput_misc = {