[PATCH] Return EINVAL if read size is not multiple of struct size

[PATCH] Return EINVAL if read size is not multiple of struct size

[James Lamanna]

The following is a small patch to return EINVAL when the value given
to read() from an event device is not a multiple of 
sizeof(struct input_event).

Prior to this patch read() with a size less than sizeof(struct input_event)
would always return 0.
This should probably be marked as an error.

Signed-off by: James Lamanna

--- linux-2.6.9/drivers/input/evdev.c   2004-10-18 14:54:40.000000000 -0700
+++ linux-2.6.9-ev-patch/drivers/input/evdev.c  2004-11-08 12:23:45.495800064 -0800
@@ -183,6 +183,9 @@
        if (!list->evdev->exist)
                return -ENODEV;

+       if (count % sizeof(struct input_event) != 0)
+               return -EINVAL;
+
        while (list->head != list->tail && retval + sizeof(struct input_event) <= count) {
                if (copy_to_user(buffer + retval, list->buffer + list->tail,
                         sizeof(struct input_event))) return -EFAULT;
-- 
James Lamanna