rfkill: detect bogus double-registering (v2)
Detect and abort with -EEXIST if rfkill_register is called twice on the
same rfkill struct. And WARN_ON(it) for good measure.
While at it, flag when we are adding the first switch of a type, we will
need that information later.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/rfkill/rfkill.c b/net/rfkill/rfkill.c
index 35a9994..1f23de2 100644
--- a/net/rfkill/rfkill.c
+++ b/net/rfkill/rfkill.c
@@ -525,17 +525,44 @@
.dev_uevent = rfkill_dev_uevent,
};
+static int rfkill_check_duplicity(const struct rfkill *rfkill)
+{
+ struct rfkill *p;
+ unsigned long seen[BITS_TO_LONGS(RFKILL_TYPE_MAX)];
+
+ memset(seen, 0, sizeof(seen));
+
+ list_for_each_entry(p, &rfkill_list, node) {
+ if (p == rfkill) {
+ WARN_ON(1);
+ return -EEXIST;
+ }
+ set_bit(p->type, seen);
+ }
+
+ /* 0: first switch of its kind */
+ return test_bit(rfkill->type, seen);
+}
+
static int rfkill_add_switch(struct rfkill *rfkill)
{
+ int error;
+
mutex_lock(&rfkill_mutex);
+ error = rfkill_check_duplicity(rfkill);
+ if (error < 0)
+ goto unlock_out;
+
rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type], 0);
list_add_tail(&rfkill->node, &rfkill_list);
+ error = 0;
+unlock_out:
mutex_unlock(&rfkill_mutex);
- return 0;
+ return error;
}
static void rfkill_remove_switch(struct rfkill *rfkill)