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

[Parav Pandit]

> From: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Sent: Thursday, April 8, 2021 5:46 PM
> 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.
Only cma.c needs a fixing. cm.c also reports EOPNOTSUPP.
I will send the simplified fix through Leon.