[PATCH for-next] rdma_rxe: address an issue with hardened user copy

[Bob Pearson <rpearsonhpe@gmail.com>]

Change rxe pools to use kzalloc instead of kmem_cache to allocate
memory for rxe objects.

Signed-off-by: Bob Pearson <rpearson@hpe.com>
---
 drivers/infiniband/sw/rxe/rxe.c      |  8 ----
 drivers/infiniband/sw/rxe/rxe_pool.c | 60 +---------------------------
 drivers/infiniband/sw/rxe/rxe_pool.h |  7 ----
 3 files changed, 2 insertions(+), 73 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe.c b/drivers/infiniband/sw/rxe/rxe.c
index cc395da13eff..a1ff70e0b1f8 100644
--- a/drivers/infiniband/sw/rxe/rxe.c
+++ b/drivers/infiniband/sw/rxe/rxe.c
@@ -277,13 +277,6 @@ static int __init rxe_module_init(void)
 {
 	int err;
 
-	/* initialize slab caches for managed objects */
-	err = rxe_cache_init();
-	if (err) {
-		pr_err("unable to init object pools\n");
-		return err;
-	}
-
 	err = rxe_net_init();
 	if (err)
 		return err;
@@ -298,7 +291,6 @@ static void __exit rxe_module_exit(void)
 	rdma_link_unregister(&rxe_link_ops);
 	ib_unregister_driver(RDMA_DRIVER_RXE);
 	rxe_net_exit();
-	rxe_cache_exit();
 
 	pr_info("unloaded\n");
 }
diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c
index c0fab4a65f9e..70fc9f7a25b6 100644
--- a/drivers/infiniband/sw/rxe/rxe_pool.c
+++ b/drivers/infiniband/sw/rxe/rxe_pool.c
@@ -84,62 +84,6 @@ static inline const char *pool_name(struct rxe_pool *pool)
 	return rxe_type_info[pool->type].name;
 }
 
-static inline struct kmem_cache *pool_cache(struct rxe_pool *pool)
-{
-	return rxe_type_info[pool->type].cache;
-}
-
-static void rxe_cache_clean(size_t cnt)
-{
-	int i;
-	struct rxe_type_info *type;
-
-	for (i = 0; i < cnt; i++) {
-		type = &rxe_type_info[i];
-		if (!(type->flags & RXE_POOL_NO_ALLOC)) {
-			kmem_cache_destroy(type->cache);
-			type->cache = NULL;
-		}
-	}
-}
-
-int rxe_cache_init(void)
-{
-	int err;
-	int i;
-	size_t size;
-	struct rxe_type_info *type;
-
-	for (i = 0; i < RXE_NUM_TYPES; i++) {
-		type = &rxe_type_info[i];
-		size = ALIGN(type->size, RXE_POOL_ALIGN);
-		if (!(type->flags & RXE_POOL_NO_ALLOC)) {
-			type->cache =
-				kmem_cache_create(type->name, size,
-						  RXE_POOL_ALIGN,
-						  RXE_POOL_CACHE_FLAGS, NULL);
-			if (!type->cache) {
-				pr_err("Unable to init kmem cache for %s\n",
-				       type->name);
-				err = -ENOMEM;
-				goto err1;
-			}
-		}
-	}
-
-	return 0;
-
-err1:
-	rxe_cache_clean(i);
-
-	return err;
-}
-
-void rxe_cache_exit(void)
-{
-	rxe_cache_clean(RXE_NUM_TYPES);
-}
-
 static int rxe_pool_init_index(struct rxe_pool *pool, u32 max, u32 min)
 {
 	int err = 0;
@@ -381,7 +325,7 @@ void *rxe_alloc(struct rxe_pool *pool)
 	if (atomic_inc_return(&pool->num_elem) > pool->max_elem)
 		goto out_cnt;
 
-	elem = kmem_cache_zalloc(pool_cache(pool),
+	elem = kzalloc(rxe_type_info[pool->type].size,
 				 (pool->flags & RXE_POOL_ATOMIC) ?
 				 GFP_ATOMIC : GFP_KERNEL);
 	if (!elem)
@@ -443,7 +387,7 @@ void rxe_elem_release(struct kref *kref)
 		pool->cleanup(elem);
 
 	if (!(pool->flags & RXE_POOL_NO_ALLOC))
-		kmem_cache_free(pool_cache(pool), elem);
+		kfree(elem);
 	atomic_dec(&pool->num_elem);
 	ib_device_put(&pool->rxe->ib_dev);
 	rxe_pool_put(pool);
diff --git a/drivers/infiniband/sw/rxe/rxe_pool.h b/drivers/infiniband/sw/rxe/rxe_pool.h
index 64d92be3f060..3d722aae5f15 100644
--- a/drivers/infiniband/sw/rxe/rxe_pool.h
+++ b/drivers/infiniband/sw/rxe/rxe_pool.h
@@ -42,7 +42,6 @@ struct rxe_type_info {
 	u32			min_index;
 	size_t			key_offset;
 	size_t			key_size;
-	struct kmem_cache	*cache;
 };
 
 extern struct rxe_type_info rxe_type_info[];
@@ -96,12 +95,6 @@ struct rxe_pool {
 	} key;
 };
 
-/* initialize slab caches for managed objects */
-int rxe_cache_init(void);
-
-/* cleanup slab caches for managed objects */
-void rxe_cache_exit(void);
-
 /* initialize a pool of objects with given limit on
  * number of elements. gets parameters from rxe_type_info
  * pool elements will be allocated out of a slab cache
-- 
2.25.1