Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit c0cfe7fa authored by G. Liakhovetski's avatar G. Liakhovetski Committed by David S. Miller
Browse files

[IrDA]: Fix Rx/Tx path race. 



From: G. Liakhovetski <gl@dsa-ac.de>

We need to switch to NRM _before_ sending the final packet otherwise
we might hit a race condition where we get the first packet from the
peer while we're still in LAP_XMIT_P.

Signed-off-by: default avatarSamuel Ortiz <samuel@sortiz.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 81d84a94

include/net/irda/irlap.h

+17 −0
Original line number Diff line number Diff line
@@ -289,4 +289,21 @@ static inline void irlap_clear_disconnect(struct irlap_cb *self) 
	self->disconnect_pending = FALSE;

}



/*

 * Function irlap_next_state (self, state)

 *

 *    Switches state and provides debug information

 *

 */

static inline void irlap_next_state(struct irlap_cb *self, IRLAP_STATE state)

{

	/*

	if (!self || self->magic != LAP_MAGIC)

		return;



	IRDA_DEBUG(4, "next LAP state = %s\n", irlap_state[state]);

	*/

	self->state = state;

}



#endif

net/irda/irlap_event.c

+0 −18
Original line number Diff line number Diff line
@@ -316,23 +316,6 @@ void irlap_do_event(struct irlap_cb *self, IRLAP_EVENT event, 
	}

}



/*

 * Function irlap_next_state (self, state)

 *

 *    Switches state and provides debug information

 *

 */

static inline void irlap_next_state(struct irlap_cb *self, IRLAP_STATE state)

{

	/*

	if (!self || self->magic != LAP_MAGIC)

		return;



	IRDA_DEBUG(4, "next LAP state = %s\n", irlap_state[state]);

	*/

	self->state = state;

}



/*

 * Function irlap_state_ndm (event, skb, frame)

 *
@@ -1086,7 +1069,6 @@ static int irlap_state_xmit_p(struct irlap_cb *self, IRLAP_EVENT event, 
			} else {

				/* Final packet of window */

				irlap_send_data_primary_poll(self, skb);

				irlap_next_state(self, LAP_NRM_P);



				/*

				 * Make sure state machine does not try to send

net/irda/irlap_frame.c

+3 −0
Original line number Diff line number Diff line
@@ -798,16 +798,19 @@ void irlap_send_data_primary_poll(struct irlap_cb *self, struct sk_buff *skb) 
		self->vs = (self->vs + 1) % 8;

		self->ack_required = FALSE;



		irlap_next_state(self, LAP_NRM_P);

		irlap_send_i_frame(self, tx_skb, CMD_FRAME);

	} else {

		IRDA_DEBUG(4, "%s(), sending unreliable frame\n", __FUNCTION__);



		if (self->ack_required) {

			irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);

			irlap_next_state(self, LAP_NRM_P);

			irlap_send_rr_frame(self, CMD_FRAME);

			self->ack_required = FALSE;

		} else {

			skb->data[1] |= PF_BIT;

			irlap_next_state(self, LAP_NRM_P);

			irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);

		}

	}