rfkill: mutex fixes
There are two mutexes in rfkill:
rfkill->mutex, which protects some of the fields of a rfkill struct, and is
also used for callback serialization.
rfkill_mutex, which protects the global state, the list of registered
rfkill structs and rfkill->claim.
Make sure to use the correct mutex, and to not miss locking rfkill->mutex
even when we already took rfkill_mutex.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/rfkill/rfkill.c b/net/rfkill/rfkill.c
index fc3a4fd..ac205ec 100644
--- a/net/rfkill/rfkill.c
+++ b/net/rfkill/rfkill.c
@@ -150,7 +150,7 @@
* even if the radio is in RFKILL_STATE_HARD_BLOCKED state, so as to
* give the driver a hint that it should double-BLOCK the transmitter.
*
- * Caller must have aquired rfkill_mutex.
+ * Caller must have acquired rfkill->mutex.
*/
static int rfkill_toggle_radio(struct rfkill *rfkill,
enum rfkill_state state,
@@ -216,8 +216,11 @@
rfkill_states[type] = state;
list_for_each_entry(rfkill, &rfkill_list, node) {
- if ((!rfkill->user_claim) && (rfkill->type == type))
+ if ((!rfkill->user_claim) && (rfkill->type == type)) {
+ mutex_lock(&rfkill->mutex);
rfkill_toggle_radio(rfkill, state, 0);
+ mutex_unlock(&rfkill->mutex);
+ }
}
mutex_unlock(&rfkill_mutex);
@@ -228,7 +231,7 @@
* rfkill_epo - emergency power off all transmitters
*
* This kicks all rfkill devices to RFKILL_STATE_SOFT_BLOCKED, ignoring
- * everything in its path but rfkill_mutex.
+ * everything in its path but rfkill_mutex and rfkill->mutex.
*/
void rfkill_epo(void)
{
@@ -236,7 +239,9 @@
mutex_lock(&rfkill_mutex);
list_for_each_entry(rfkill, &rfkill_list, node) {
+ mutex_lock(&rfkill->mutex);
rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
+ mutex_unlock(&rfkill->mutex);
}
mutex_unlock(&rfkill_mutex);
}
@@ -372,6 +377,9 @@
if (!capable(CAP_NET_ADMIN))
return -EPERM;
+ if (rfkill->user_claim_unsupported)
+ return -EOPNOTSUPP;
+
/*
* Take the global lock to make sure the kernel is not in
* the middle of rfkill_switch_all
@@ -380,19 +388,17 @@
if (error)
return error;
- if (rfkill->user_claim_unsupported) {
- error = -EOPNOTSUPP;
- goto out_unlock;
- }
if (rfkill->user_claim != claim) {
- if (!claim)
+ if (!claim) {
+ mutex_lock(&rfkill->mutex);
rfkill_toggle_radio(rfkill,
rfkill_states[rfkill->type],
0);
+ mutex_unlock(&rfkill->mutex);
+ }
rfkill->user_claim = claim;
}
-out_unlock:
mutex_unlock(&rfkill_mutex);
return error ? error : count;
@@ -521,8 +527,11 @@
{
mutex_lock(&rfkill_mutex);
list_del_init(&rfkill->node);
- rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
mutex_unlock(&rfkill_mutex);
+
+ mutex_lock(&rfkill->mutex);
+ rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
+ mutex_unlock(&rfkill->mutex);
}
/**