sfc: extend the locking on mcdi->seqno

seqno could be read as a stale value outside of the lock. The lock is
already acquired to protect the modification of seqno against a possible
race condition. Place the reading of this value also inside this locking
to protect it against a possible race condition.

Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
Acked-by: Martin Habets <habetsm.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Niels Dossche 2022-03-01 23:28:22 +01:00 committed by David S. Miller
parent f8e9bd34ce
commit f1fb205efb

View File

@ -163,9 +163,9 @@ static void efx_mcdi_send_request(struct efx_nic *efx, unsigned cmd,
/* Serialise with efx_mcdi_ev_cpl() and efx_mcdi_ev_death() */
spin_lock_bh(&mcdi->iface_lock);
++mcdi->seqno;
seqno = mcdi->seqno & SEQ_MASK;
spin_unlock_bh(&mcdi->iface_lock);
seqno = mcdi->seqno & SEQ_MASK;
xflags = 0;
if (mcdi->mode == MCDI_MODE_EVENTS)
xflags |= MCDI_HEADER_XFLAGS_EVREQ;