From: Weihang Li liweihang@huawei.com
[ Upstream commit 82eb481da64586ccd287b2b2c5a086202c65e7eb ]
refcount_t is better than integer for reference counting, it will WARN on overflow/underflow and avoid use-after-free risks.
Link: https://lore.kernel.org/r/1621589395-2435-5-git-send-email-liweihang@huawei.... Signed-off-by: Weihang Li liweihang@huawei.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Stable-dep-of: cf5b608fb0e3 ("RDMA/hns: Fix hns_roce_table_get return value") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/hw/hns/hns_roce_hem.c | 32 +++++++++++------------- drivers/infiniband/hw/hns/hns_roce_hem.h | 4 +-- 2 files changed, 17 insertions(+), 19 deletions(-)
diff --git a/drivers/infiniband/hw/hns/hns_roce_hem.c b/drivers/infiniband/hw/hns/hns_roce_hem.c index edc287a0a91a1..831e9476c6284 100644 --- a/drivers/infiniband/hw/hns/hns_roce_hem.c +++ b/drivers/infiniband/hw/hns/hns_roce_hem.c @@ -260,7 +260,6 @@ static struct hns_roce_hem *hns_roce_alloc_hem(struct hns_roce_dev *hr_dev, if (!hem) return NULL;
- hem->refcount = 0; INIT_LIST_HEAD(&hem->chunk_list);
order = get_order(hem_alloc_size); @@ -607,7 +606,7 @@ static int hns_roce_table_mhop_get(struct hns_roce_dev *hr_dev,
mutex_lock(&table->mutex); if (table->hem[index.buf]) { - ++table->hem[index.buf]->refcount; + refcount_inc(&table->hem[index.buf]->refcount); goto out; }
@@ -626,7 +625,7 @@ static int hns_roce_table_mhop_get(struct hns_roce_dev *hr_dev, } }
- ++table->hem[index.buf]->refcount; + refcount_set(&table->hem[index.buf]->refcount, 1); goto out;
err_alloc: @@ -652,7 +651,7 @@ int hns_roce_table_get(struct hns_roce_dev *hr_dev, mutex_lock(&table->mutex);
if (table->hem[i]) { - ++table->hem[i]->refcount; + refcount_inc(&table->hem[i]->refcount); goto out; }
@@ -675,7 +674,7 @@ int hns_roce_table_get(struct hns_roce_dev *hr_dev, goto out; }
- ++table->hem[i]->refcount; + refcount_set(&table->hem[i]->refcount, 1); out: mutex_unlock(&table->mutex); return ret; @@ -742,11 +741,11 @@ static void hns_roce_table_mhop_put(struct hns_roce_dev *hr_dev, return; }
- mutex_lock(&table->mutex); - if (check_refcount && (--table->hem[index.buf]->refcount > 0)) { - mutex_unlock(&table->mutex); + if (!check_refcount) + mutex_lock(&table->mutex); + else if (!refcount_dec_and_mutex_lock(&table->hem[index.buf]->refcount, + &table->mutex)) return; - }
clear_mhop_hem(hr_dev, table, obj, &mhop, &index); free_mhop_hem(hr_dev, table, &mhop, &index); @@ -768,16 +767,15 @@ void hns_roce_table_put(struct hns_roce_dev *hr_dev, i = (obj & (table->num_obj - 1)) / (table->table_chunk_size / table->obj_size);
- mutex_lock(&table->mutex); + if (!refcount_dec_and_mutex_lock(&table->hem[i]->refcount, + &table->mutex)) + return;
- if (--table->hem[i]->refcount == 0) { - /* Clear HEM base address */ - if (hr_dev->hw->clear_hem(hr_dev, table, obj, 0)) - dev_warn(dev, "Clear HEM base address failed.\n"); + if (hr_dev->hw->clear_hem(hr_dev, table, obj, 0)) + dev_warn(dev, "failed to clear HEM base address.\n");
- hns_roce_free_hem(hr_dev, table->hem[i]); - table->hem[i] = NULL; - } + hns_roce_free_hem(hr_dev, table->hem[i]); + table->hem[i] = NULL;
mutex_unlock(&table->mutex); } diff --git a/drivers/infiniband/hw/hns/hns_roce_hem.h b/drivers/infiniband/hw/hns/hns_roce_hem.h index 112243d112c23..03d44e2efa473 100644 --- a/drivers/infiniband/hw/hns/hns_roce_hem.h +++ b/drivers/infiniband/hw/hns/hns_roce_hem.h @@ -87,8 +87,8 @@ struct hns_roce_hem_chunk { };
struct hns_roce_hem { - struct list_head chunk_list; - int refcount; + struct list_head chunk_list; + refcount_t refcount; };
struct hns_roce_hem_iter {