[PATCH v2 11/16] rdma_rxe: Address an issue with hardened user copy

[Bob Pearson <rpearsonhpe@xxxxxxxxx>]

Added a new feature to pools to let driver white list a region of
a pool object. This removes a kernel oops caused when create qp
returns the qp number so the next patch will work without errors.

Signed-off-by: Bob Pearson <rpearson@xxxxxxx>
---
 drivers/infiniband/sw/rxe/rxe_pool.c | 20 +++++++++++++++++---
 drivers/infiniband/sw/rxe/rxe_pool.h |  4 ++++
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c
index 5679714827ec..374e56689d30 100644
--- a/drivers/infiniband/sw/rxe/rxe_pool.c
+++ b/drivers/infiniband/sw/rxe/rxe_pool.c
@@ -40,9 +40,12 @@ struct rxe_type_info rxe_type_info[RXE_NUM_TYPES] = {
 		.name		= "rxe-qp",
 		.size		= sizeof(struct rxe_qp),
 		.cleanup	= rxe_qp_cleanup,
-		.flags		= RXE_POOL_INDEX,
+		.flags		= RXE_POOL_INDEX
+				| RXE_POOL_WHITELIST,
 		.min_index	= RXE_MIN_QP_INDEX,
 		.max_index	= RXE_MAX_QP_INDEX,
+		.user_offset	= offsetof(struct rxe_qp, ibqp.qp_num),
+		.user_size	= sizeof(u32),
 	},
 	[RXE_TYPE_CQ] = {
 		.name		= "rxe-cq",
@@ -116,10 +119,21 @@ int rxe_cache_init(void)
 		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,
+			if (type->flags & RXE_POOL_WHITELIST) {
+				type->cache =
+					kmem_cache_create_usercopy(
+						type->name, size,
+						RXE_POOL_ALIGN,
+						RXE_POOL_CACHE_FLAGS,
+						type->user_offset,
+						type->user_size, NULL);
+			} else {
+				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);
diff --git a/drivers/infiniband/sw/rxe/rxe_pool.h b/drivers/infiniband/sw/rxe/rxe_pool.h
index 664153bf9392..fc5b584a8137 100644
--- a/drivers/infiniband/sw/rxe/rxe_pool.h
+++ b/drivers/infiniband/sw/rxe/rxe_pool.h
@@ -17,6 +17,7 @@ enum rxe_pool_flags {
 	RXE_POOL_INDEX		= BIT(1),
 	RXE_POOL_KEY		= BIT(2),
 	RXE_POOL_NO_ALLOC	= BIT(4),
+	RXE_POOL_WHITELIST	= BIT(5),
 };
 
 enum rxe_elem_type {
@@ -44,6 +45,9 @@ struct rxe_type_info {
 	u32			min_index;
 	size_t			key_offset;
 	size_t			key_size;
+	/* for white listing where necessary */
+	unsigned int		user_offset;
+	unsigned int		user_size;
 	struct kmem_cache	*cache;
 };
 
-- 
2.25.1