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, 135 insertions, 0 deletions

diff --git a/drivers/input/input-compat.c b/drivers/input/input-compat.c
new file mode 100644
index 000000000000..1accb89ae66f
--- /dev/null
+++ b/drivers/input/input-compat.c
@@ -0,0 +1,135 @@
+/*
+ * 32bit compatibility wrappers for the input subsystem.
+ *
+ * Very heavily based on evdev.c - 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.
+ */
+
+#include <asm/uaccess.h>
+#include "input-compat.h"
+
+#ifdef CONFIG_COMPAT
+
+int input_event_from_user(const char __user *buffer,
+                          struct input_event *event)
+{
+        if (INPUT_COMPAT_TEST) {
+                struct input_event_compat compat_event;
+
+                if (copy_from_user(&compat_event, buffer,
+                                   sizeof(struct input_event_compat)))
+                        return -EFAULT;
+
+                event->time.tv_sec = compat_event.time.tv_sec;
+                event->time.tv_usec = compat_event.time.tv_usec;
+                event->type = compat_event.type;
+                event->code = compat_event.code;
+                event->value = compat_event.value;
+
+        } else {
+                if (copy_from_user(event, buffer, sizeof(struct input_event)))
+                        return -EFAULT;
+        }
+
+        return 0;
+}
+
+int input_event_to_user(char __user *buffer,
+                        const struct input_event *event)
+{
+        if (INPUT_COMPAT_TEST) {
+                struct input_event_compat compat_event;
+
+                compat_event.time.tv_sec = event->time.tv_sec;
+                compat_event.time.tv_usec = event->time.tv_usec;
+                compat_event.type = event->type;
+                compat_event.code = event->code;
+                compat_event.value = event->value;
+
+                if (copy_to_user(buffer, &compat_event,
+                                 sizeof(struct input_event_compat)))
+                        return -EFAULT;
+
+        } else {
+                if (copy_to_user(buffer, event, sizeof(struct input_event)))
+                        return -EFAULT;
+        }
+
+        return 0;
+}
+
+int input_ff_effect_from_user(const char __user *buffer, size_t size,
+                              struct ff_effect *effect)
+{
+        if (INPUT_COMPAT_TEST) {
+                struct ff_effect_compat *compat_effect;
+
+                if (size != sizeof(struct ff_effect_compat))
+                        return -EINVAL;
+
+                /*
+                 * It so happens that the pointer which needs to be changed
+                 * is the last field in the structure, so we can retrieve the
+                 * whole thing and replace just the pointer.
+                 */
+                compat_effect = (struct ff_effect_compat *)effect;
+
+                if (copy_from_user(compat_effect, buffer,
+                                   sizeof(struct ff_effect_compat)))
+                        return -EFAULT;
+
+                if (compat_effect->type == FF_PERIODIC &&
+                    compat_effect->u.periodic.waveform == FF_CUSTOM)
+                        effect->u.periodic.custom_data =
+                                compat_ptr(compat_effect->u.periodic.custom_data);
+        } else {
+                if (size != sizeof(struct ff_effect))
+                        return -EINVAL;
+
+                if (copy_from_user(effect, buffer, sizeof(struct ff_effect)))
+                        return -EFAULT;
+        }
+
+        return 0;
+}
+
+#else
+
+int input_event_from_user(const char __user *buffer,
+                         struct input_event *event)
+{
+        if (copy_from_user(event, buffer, sizeof(struct input_event)))
+                return -EFAULT;
+
+        return 0;
+}
+
+int input_event_to_user(char __user *buffer,
+                        const struct input_event *event)
+{
+        if (copy_to_user(buffer, event, sizeof(struct input_event)))
+                return -EFAULT;
+
+        return 0;
+}
+
+int input_ff_effect_from_user(const char __user *buffer, size_t size,
+                              struct ff_effect *effect)
+{
+        if (size != sizeof(struct ff_effect))
+                return -EINVAL;
+
+        if (copy_from_user(effect, buffer, sizeof(struct ff_effect)))
+                return -EFAULT;
+
+        return 0;
+}
+
+#endif /* CONFIG_COMPAT */
+
+EXPORT_SYMBOL_GPL(input_event_from_user);
+EXPORT_SYMBOL_GPL(input_event_to_user);
+EXPORT_SYMBOL_GPL(input_ff_effect_from_user);