RDMA/efa: Fix wrong resources deallocation order

[ Upstream commit dc202c57e9a1423aed528e4b8dc949509cd32191 ]

When trying to destroy QP or CQ, we first decrease the refcount and
potentially free memory regions allocated for the object and then
request the device to destroy the object. If the device fails, the
object isn't fully destroyed so the user/IB core can try to destroy the
object again which will lead to underflow when trying to decrease an
already zeroed refcount.

Deallocate resources in reverse order of allocating them to safely free
them.

Fixes: ff6629f88c52 ("RDMA/efa: Do not delay freeing of DMA pages")
Reviewed-by: Michael Margolin <mrgolin@amazon.com>
Reviewed-by: Yossi Leybovich <sleybo@amazon.com>
Signed-off-by: Yonatan Nachum <ynachum@amazon.com>
Link: https://lore.kernel.org/r/20230822082725.31719-1-ynachum@amazon.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/infiniband/hw/efa/efa_verbs.c b/drivers/infiniband/hw/efa/efa_verbs.c
index 2a195c4b0f17de077a87b6ff7a8fed4e837f03ad..3538d59521e41df4b3d12b066384a68e8f29a3c2 100644 (file)
--- a/drivers/infiniband/hw/efa/efa_verbs.c
+++ b/drivers/infiniband/hw/efa/efa_verbs.c
@@ -449,12 +449,12 @@ int efa_destroy_qp(struct ib_qp *ibqp, struct ib_udata *udata)
 
        ibdev_dbg(&dev->ibdev, "Destroy qp[%u]\n", ibqp->qp_num);
 
-       efa_qp_user_mmap_entries_remove(qp);
-
        err = efa_destroy_qp_handle(dev, qp->qp_handle);
        if (err)
                return err;
 
+       efa_qp_user_mmap_entries_remove(qp);
+
        if (qp->rq_cpu_addr) {
                ibdev_dbg(&dev->ibdev,
                          "qp->cpu_addr[0x%p] freed: size[%lu], dma[%pad]\n",
@@ -1013,8 +1013,8 @@ int efa_destroy_cq(struct ib_cq *ibcq, struct ib_udata *udata)
                  "Destroy cq[%d] virt[0x%p] freed: size[%lu], dma[%pad]\n",
                  cq->cq_idx, cq->cpu_addr, cq->size, &cq->dma_addr);
 
-       efa_cq_user_mmap_entries_remove(cq);
        efa_destroy_cq_idx(dev, cq->cq_idx);
+       efa_cq_user_mmap_entries_remove(cq);
        if (cq->eq) {
                xa_erase(&dev->cqs_xa, cq->cq_idx);
                synchronize_irq(cq->eq->irq.irqn);