RDMA/hns: Use refcount_t instead of atomic_t for SRQ reference counting

The refcount_t API will WARN on underflow and overflow of a reference
counter, and avoid use-after-free risks.

Link: https://lore.kernel.org/r/1622194663-2383-10-git-send-email-liweihang@huawei.com
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/infiniband/hw/hns/hns_roce_device.h b/drivers/infiniband/hw/hns/hns_roce_device.h
index cbb6901c0d7cda198261ccdbdbb10cd8d29f1a82..bd190219755144123a5c195d233b705232bbc6fd 100644 (file)
--- a/drivers/infiniband/hw/hns/hns_roce_device.h
+++ b/drivers/infiniband/hw/hns/hns_roce_device.h
@@ -471,7 +471,7 @@ struct hns_roce_srq {
        u32                     xrcdn;
        void __iomem            *db_reg;
 
-       atomic_t                refcount;
+       refcount_t              refcount;
        struct completion       free;
 
        struct hns_roce_mtr     buf_mtr;

diff --git a/drivers/infiniband/hw/hns/hns_roce_srq.c b/drivers/infiniband/hw/hns/hns_roce_srq.c
index c842210f7c47584a3e5da29bc4c0b7f520cbfc33..d6680514d20f2a96492702a942aa021e75856733 100644 (file)
--- a/drivers/infiniband/hw/hns/hns_roce_srq.c
+++ b/drivers/infiniband/hw/hns/hns_roce_srq.c
@@ -17,7 +17,7 @@ void hns_roce_srq_event(struct hns_roce_dev *hr_dev, u32 srqn, int event_type)
        xa_lock(&srq_table->xa);
        srq = xa_load(&srq_table->xa, srqn & (hr_dev->caps.num_srqs - 1));
        if (srq)
-               atomic_inc(&srq->refcount);
+               refcount_inc(&srq->refcount);
        xa_unlock(&srq_table->xa);
 
        if (!srq) {
@@ -27,7 +27,7 @@ void hns_roce_srq_event(struct hns_roce_dev *hr_dev, u32 srqn, int event_type)
 
        srq->event(srq, event_type);
 
-       if (atomic_dec_and_test(&srq->refcount))
+       if (refcount_dec_and_test(&srq->refcount))
                complete(&srq->free);
 }
 
@@ -149,7 +149,7 @@ static void free_srqc(struct hns_roce_dev *hr_dev, struct hns_roce_srq *srq)
 
        xa_erase(&srq_table->xa, srq->srqn);
 
-       if (atomic_dec_and_test(&srq->refcount))
+       if (refcount_dec_and_test(&srq->refcount))
                complete(&srq->free);
        wait_for_completion(&srq->free);
 
@@ -417,7 +417,7 @@ int hns_roce_create_srq(struct ib_srq *ib_srq,
 
        srq->db_reg = hr_dev->reg_base + SRQ_DB_REG;
        srq->event = hns_roce_ib_srq_event;
-       atomic_set(&srq->refcount, 1);
+       refcount_set(&srq->refcount, 1);
        init_completion(&srq->free);
 
        return 0;