On Wed, 07 Apr 2010 15:41:30 +0200, Michal Nazarewicz <m.nazarewicz@xxxxxxxxxxx> wrote:
+static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf,
+ size_t n)
+{
+ /* We are holding ffs->ev.waitq.lock and ffs->mutex and we need
+ * to release them. */
+
+ struct usb_functionfs_event events[n];
+ unsigned i = 0;
+
+ memset(events, 0, sizeof events);
+
+ do {
+ events[i].type = ffs->ev.types[i];
+ if (events[i].type == FUNCTIONFS_SETUP) {
+ events[i].u.setup = ffs->ev.setup;
+ ffs->setup_state = FFS_SETUP_PENDING;
+ }
+ } while (++i < n);
+
+ ffs->ev.count = 0;
I've just noticed. This line should instead read:
+ if (n < ffs->ev.count) {
+ ffs->ev.count -= n;
+ memmove(ffs->ev.types, ffs->ev.types + n,
+ ffs->ev.count * sizeof *ffs->ev.types);
+ } else {
+ ffs->ev.count = 0;
+ }
This is a minor bug which should be rather hard to observe (and only
if user-space reads() less then 4 * sizeof(struct usb_functionfs_event)
bytes when reading from "ep0") so posted code is good for testing.
(I'll post a fixed version later on with possibly other fixes and
changes.)
+
+ spin_unlock_irq(&ffs->ev.waitq.lock);
+ mutex_unlock(&ffs->mutex);
+
+ return unlikely(__copy_to_user(buf, events, sizeof events))
+ ? -EFAULT : sizeof events;
+}
--
Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, Michał "mina86" Nazarewicz (o o)
ooo +---[mina86@xxxxxxxxxx]---[mina86@jabber.org]---ooO--(_)--Ooo--
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
