From 414ed90cee32486c50f91b28990443e0dc21c868 Mon Sep 17 00:00:00 2001 From: Mike Marciniszyn Date: Thu, 10 Feb 2011 14:11:28 +0000 Subject: [PATCH] IB/qib: Fix double add_timer() The following panic BUG_ON occurs during qib testing: Kernel BUG at include/linux/timer.h:82 RIP [] :ib_qib:start_timer+0x73/0x89 RSP <0>Kernel panic - not syncing: Fatal exception <0>Dumping qib trace buffer from panic qib_set_lid INFO: IB0:1 got a lid: 0xf8 Done dumping qib trace buffer BUG: warning at kernel/panic.c:137/panic() (Tainted: G The flaw is due to a missing state test when processing responses that results in an add_timer() call when the same timer is already queued. This code was executing in parallel with a QP destroy on another CPU that had changed the state to reset, but the missing test caused to response handling code to run on into the panic. Signed-off-by: Mike Marciniszyn Signed-off-by: Roland Dreier --- drivers/infiniband/hw/qib/qib_rc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/infiniband/hw/qib/qib_rc.c b/drivers/infiniband/hw/qib/qib_rc.c index 8245237b67c..31e09b05a1a 100644 --- a/drivers/infiniband/hw/qib/qib_rc.c +++ b/drivers/infiniband/hw/qib/qib_rc.c @@ -1439,6 +1439,8 @@ static void qib_rc_rcv_resp(struct qib_ibport *ibp, } spin_lock_irqsave(&qp->s_lock, flags); + if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK)) + goto ack_done; /* Ignore invalid responses. */ if (qib_cmp24(psn, qp->s_next_psn) >= 0) -- 2.39.2