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Unlock before BUG, but preserve normal operation

PATCH New Roel Kluin 1 participant 1 message Oct 26, 2007

Subsystems (4)
Networking Network drivers Networking drivers (wireless) Rxrpc sockets (AF_RXRPC)
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Roel Kluin

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PATCH 1/1 Unlock before BUG, but preserve normal operation

I am a bit uncertain about this, so if you have comments on this, it is much appreciated.

The rationale:
in the default case the BUG() kills the current process, but with the lock still held this causes the system to hang; therefore the unlock before the BUG().

When CONFIG_BUG is disabled - e.g. for embedded systems - the BUG(); will not kill the process and there should not be a double unlock in that case. --
Unlock before BUG(), but preserve normal operation in the case that CONFIG_BUG is disabled.

Signed-off-by Roel Kluin <[email protected]>

---

drivers/net/wireless/ipw2200.c +2 -0
index e3c8284..f337578 100644
@@ -8722,7 +8722,9 @@ static int ipw_wx_get_freq(struct net_device *dev,
 			break;
 
 		default:
+			mutex_unlock(&priv->mutex);
 			BUG();
+			return -EINVAL;
 		}
 	} else
 		wrqu->freq.m = 0;
net/rxrpc/ar-ack.c +4 -1
index 657ee69..e551b0b 100644
@@ -752,8 +752,11 @@ all_acked:
 		sp->call = call;
 		rxrpc_get_call(call);
 		spin_lock_bh(&call->lock);
-		if (rxrpc_queue_rcv_skb(call, skb, true, true) < 0)
+		if (rxrpc_queue_rcv_skb(call, skb, true, true) < 0) {
+			spin_unlock_bh(&call->lock);
 			BUG();
+			goto process_further;
+		}
 		spin_unlock_bh(&call->lock);
 		goto process_further;
 	}
net/rxrpc/ar-call.c +5 -2
index 3c04b00..48804e1 100644
@@ -426,9 +426,12 @@ void rxrpc_release_call(struct rxrpc_call *call)
 	       call->rx_first_oos);
 
 	spin_lock_bh(&call->lock);
-	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
+	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags)) {
+		spin_unlock_bh(&call->lock);
 		BUG();
-	spin_unlock_bh(&call->lock);
+	} else {
+		spin_unlock_bh(&call->lock);
+	}
 
 	/* dissociate from the socket
 	 * - the socket's ref on the call is passed to the death timer