RDMA/core: Allow the ioctl layer to abort a fully created uobject

While creating a uobject every create reaches a point where the uobject is
fully initialized. For ioctls that go on to copy_to_user this means they
need to open code the destruction of a fully created uobject - ie the
RDMA_REMOVE_DESTROY sort of flow.

Open coding this creates bugs, eg the CQ does not properly flush the
events list when it does its error unwind.

Provide a uverbs_finalize_uobj_create() function which indicates that the
uobject is fully initialized and that abort should call to destroy_hw to
destroy the uobj->object and related.

Methods can call this function if they go on to have error cases after
setting uobj->object. Once done those error cases can simply do return,
without an error unwind.

Link: https://lore.kernel.org/r/20200519072711.257271-2-leon@kernel.org
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

1 files changed, 20 insertions, 5 deletions

diff --git a/drivers/infiniband/core/rdma_core.c b/drivers/infiniband/core/rdma_core.c
index bf8e149d3191..de3858515275 100644
--- a/drivers/infiniband/core/rdma_core.c
+++ b/drivers/infiniband/core/rdma_core.c
@@ -130,6 +130,17 @@ static int uverbs_destroy_uobject(struct ib_uobject *uobj,
 	lockdep_assert_held(&ufile->hw_destroy_rwsem);
 	assert_uverbs_usecnt(uobj, UVERBS_LOOKUP_WRITE);
 
+	if (reason == RDMA_REMOVE_ABORT_HWOBJ) {
+		reason = RDMA_REMOVE_ABORT;
+		ret = uobj->uapi_object->type_class->destroy_hw(uobj, reason,
+								attrs);
+		/*
+		 * Drivers are not permitted to ignore RDMA_REMOVE_ABORT, see
+		 * ib_is_destroy_retryable, cleanup_retryable == false here.
+		 */
+		WARN_ON(ret);
+	}
+
 	if (reason == RDMA_REMOVE_ABORT) {
 		WARN_ON(!list_empty(&uobj->list));
 		WARN_ON(!uobj->context);
@@ -647,11 +658,15 @@ void rdma_alloc_commit_uobject(struct ib_uobject *uobj,
  * object and anything else connected to uobj before calling this.
  */
 void rdma_alloc_abort_uobject(struct ib_uobject *uobj,
-			      struct uverbs_attr_bundle *attrs)
+			      struct uverbs_attr_bundle *attrs,
+			      bool hw_obj_valid)
 {
 	struct ib_uverbs_file *ufile = uobj->ufile;
 
-	uverbs_destroy_uobject(uobj, RDMA_REMOVE_ABORT, attrs);
+	uverbs_destroy_uobject(uobj,
+			       hw_obj_valid ? RDMA_REMOVE_ABORT_HWOBJ :
+					      RDMA_REMOVE_ABORT,
+			       attrs);
 
 	/* Matches the down_read in rdma_alloc_begin_uobject */
 	up_read(&ufile->hw_destroy_rwsem);
@@ -921,8 +936,8 @@ uverbs_get_uobject_from_file(u16 object_id, enum uverbs_obj_access access,
 }
 
 void uverbs_finalize_object(struct ib_uobject *uobj,
-			    enum uverbs_obj_access access, bool commit,
-			    struct uverbs_attr_bundle *attrs)
+			    enum uverbs_obj_access access, bool hw_obj_valid,
+			    bool commit, struct uverbs_attr_bundle *attrs)
 {
 	/*
 	 * refcounts should be handled at the object level and not at the
@@ -945,7 +960,7 @@ void uverbs_finalize_object(struct ib_uobject *uobj,
 		if (commit)
 			rdma_alloc_commit_uobject(uobj, attrs);
 		else
-			rdma_alloc_abort_uobject(uobj, attrs);
+			rdma_alloc_abort_uobject(uobj, attrs, hw_obj_valid);
 		break;
 	default:
 		WARN_ON(true);