[PATCH 3/4] RDMA/rxe: Invalidate MWs on QP destroy

[Dongliang Qin <cccccccccccc777777@gmail.com>]

A type-2 MW holds a reference to the QP that bound it. If the QP is
destroyed while an MW is still bound, the MW keeps the QP alive and the
responder can retain a stale QP association.

Invalidate MWs bound to the QP before removing the QP from its pool.

Fixes: 32a577b4c3a9 ("RDMA/rxe: Add support for bind MW work requests")

Cc: stable@vger.kernel.org
Signed-off-by: Dongliang Qin <cccccccccccc777777@gmail.com>
---
 drivers/infiniband/sw/rxe/rxe_loc.h   |  1 +
 drivers/infiniband/sw/rxe/rxe_mw.c    | 21 +++++++++++++++++++++
 drivers/infiniband/sw/rxe/rxe_verbs.c |  2 ++
 3 files changed, 24 insertions(+)

diff --git a/drivers/infiniband/sw/rxe/rxe_loc.h b/drivers/infiniband/sw/rxe/rxe_loc.h
index 5e95e5c5e32d6..5c648a5ef34b1 100644
--- a/drivers/infiniband/sw/rxe/rxe_loc.h
+++ b/drivers/infiniband/sw/rxe/rxe_loc.h
@@ -90,6 +90,7 @@ int rxe_alloc_mw(struct ib_mw *ibmw, struct ib_udata *udata);
 int rxe_dealloc_mw(struct ib_mw *ibmw);
 int rxe_bind_mw(struct rxe_qp *qp, struct rxe_send_wqe *wqe);
 int rxe_invalidate_mw(struct rxe_qp *qp, u32 rkey);
+void rxe_invalidate_mws(struct rxe_qp *qp);
 struct rxe_mr *rxe_mw_get_mr(struct rxe_qp *qp, int access, u32 rkey,
 			     u64 *offset);
 void rxe_mw_cleanup(struct rxe_pool_elem *elem);
diff --git a/drivers/infiniband/sw/rxe/rxe_mw.c b/drivers/infiniband/sw/rxe/rxe_mw.c
index 82e9fef89b6c3..02d20ede1a789 100644
--- a/drivers/infiniband/sw/rxe/rxe_mw.c
+++ b/drivers/infiniband/sw/rxe/rxe_mw.c
@@ -298,6 +298,27 @@ int rxe_invalidate_mw(struct rxe_qp *qp, u32 rkey)
 	return ret;
 }
 
+void rxe_invalidate_mws(struct rxe_qp *qp)
+{
+	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
+	struct rxe_mw *mw;
+	unsigned long index;
+
+	rcu_read_lock();
+	xa_for_each(&rxe->mw_pool.xa, index, mw) {
+		if (!rxe_get(mw))
+			continue;
+
+		spin_lock_bh(&mw->lock);
+		if (mw->qp == qp)
+			rxe_do_invalidate_mw(mw);
+		spin_unlock_bh(&mw->lock);
+
+		rxe_put(mw);
+	}
+	rcu_read_unlock();
+}
+
 struct rxe_mr *rxe_mw_get_mr(struct rxe_qp *qp, int access, u32 rkey,
 			     u64 *offset)
 {
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
index 8553c8402c619..c0d77cad4906b 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.c
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
@@ -658,6 +658,8 @@ static int rxe_destroy_qp(struct ib_qp *ibqp, struct ib_udata *udata)
 		goto err_out;
 	}
 
+	rxe_invalidate_mws(qp);
+
 	err = rxe_cleanup(qp);
 	if (err)
 		rxe_err_qp(qp, "cleanup failed, err = %d\n", err);
-- 
2.43.0