diff options
| author | Steve Wise <swise@opengridcomputing.com> | 2017-11-09 18:21:26 +0300 |
|---|---|---|
| committer | Doug Ledford <dledford@redhat.com> | 2017-11-14 00:59:22 +0300 |
| commit | bc52e9ca74b9a395897bb640c6671b2cbf716032 (patch) | |
| tree | bf286e85ae7597e6b6bbd744491ea49631904952 /drivers/infiniband | |
| parent | cbb40fadd31c6bbc59104e58ac95c6ef492d038b (diff) | |
| download | linux-bc52e9ca74b9a395897bb640c6671b2cbf716032.tar.xz | |
iw_cxgb4: atomically flush the qp
__flush_qp() has a race condition where during the flush operation,
the qp lock is released allowing another thread to possibly post a WR,
which corrupts the queue state, possibly causing crashes. The lock was
released to preserve the cq/qp locking hierarchy of cq first, then qp.
However releasing the qp lock is not necessary; both RQ and SQ CQ locks
can be acquired first, followed by the qp lock, and then the RQ and SQ
flushing can be done w/o unlocking.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/hw/cxgb4/qp.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/drivers/infiniband/hw/cxgb4/qp.c b/drivers/infiniband/hw/cxgb4/qp.c index fefc5fed1778..5ee7fe433136 100644 --- a/drivers/infiniband/hw/cxgb4/qp.c +++ b/drivers/infiniband/hw/cxgb4/qp.c @@ -1255,31 +1255,34 @@ static void __flush_qp(struct c4iw_qp *qhp, struct c4iw_cq *rchp, pr_debug("qhp %p rchp %p schp %p\n", qhp, rchp, schp); - /* locking hierarchy: cq lock first, then qp lock. */ + /* locking hierarchy: cqs lock first, then qp lock. */ spin_lock_irqsave(&rchp->lock, flag); + if (schp != rchp) + spin_lock(&schp->lock); spin_lock(&qhp->lock); if (qhp->wq.flushed) { spin_unlock(&qhp->lock); + if (schp != rchp) + spin_unlock(&schp->lock); spin_unlock_irqrestore(&rchp->lock, flag); return; } qhp->wq.flushed = 1; + t4_set_wq_in_error(&qhp->wq); c4iw_flush_hw_cq(rchp); c4iw_count_rcqes(&rchp->cq, &qhp->wq, &count); rq_flushed = c4iw_flush_rq(&qhp->wq, &rchp->cq, count); - spin_unlock(&qhp->lock); - spin_unlock_irqrestore(&rchp->lock, flag); - /* locking hierarchy: cq lock first, then qp lock. */ - spin_lock_irqsave(&schp->lock, flag); - spin_lock(&qhp->lock); if (schp != rchp) c4iw_flush_hw_cq(schp); sq_flushed = c4iw_flush_sq(qhp); + spin_unlock(&qhp->lock); - spin_unlock_irqrestore(&schp->lock, flag); + if (schp != rchp) + spin_unlock(&schp->lock); + spin_unlock_irqrestore(&rchp->lock, flag); if (schp == rchp) { if (t4_clear_cq_armed(&rchp->cq) && @@ -1313,8 +1316,8 @@ static void flush_qp(struct c4iw_qp *qhp) rchp = to_c4iw_cq(qhp->ibqp.recv_cq); schp = to_c4iw_cq(qhp->ibqp.send_cq); - t4_set_wq_in_error(&qhp->wq); if (qhp->ibqp.uobject) { + t4_set_wq_in_error(&qhp->wq); t4_set_cq_in_error(&rchp->cq); spin_lock_irqsave(&rchp->comp_handler_lock, flag); (*rchp->ibcq.comp_handler)(&rchp->ibcq, rchp->ibcq.cq_context); |