Subject: Re: [PATCH rdma-next 4/8] IB/core: Skip device which doesn't have necessary capabilities

From: Jason Gunthorpe <[email-masked]>
Date: Thu, 8 Apr 2021 09:16:01 -0300

On Wed, Apr 07, 2021 at 03:44:35PM +0000, Parav Pandit wrote:

> > If it returns EOPNOTUPP then the remove is never called so if it allocated
> > memory and left it allocated then it is leaking memory.
> > 
> I probably confused you. There is no leak today because add_one
> allocates memory, and later on when SA/CM etc per port cap is not
> present, it is unused left there which is freed on remove_one().
> Returning EOPNOTUPP is fine at start of add_one() before allocation.

Most of ULPs are OK, eg umad does:

	umad_dev = kzalloc(struct_size(umad_dev, ports, e - s + 1), GFP_KERNEL);
	if (!umad_dev)
		return -ENOMEM;
	for (i = s; i <= e; ++i) {
		if (!rdma_cap_ib_mad(device, i))
			continue;

	if (!count) {
		ret = -EOPNOTSUPP;
		goto free;
free:
	/* balances kref_init */
	ib_umad_dev_put(umad_dev);

It looks like only cm.c and cma.c need fixing, just fix those two.

The CM using ULPs have a different issue though..

Jason