> On 15 Jun 2021, at 07:08, Leon Romanovsky <leon@xxxxxxxxxx> wrote: > > On Mon, Jun 14, 2021 at 04:29:09PM +0000, Haakon Bugge wrote: >> >> >>> On 14 Jun 2021, at 09:25, Leon Romanovsky <leon@xxxxxxxxxx> wrote: >>> >>> On Mon, Jun 14, 2021 at 03:32:39AM +0000, Haakon Bugge wrote: >>>> >>>> >>>>> On 9 Jun 2021, at 12:40, Leon Romanovsky <leon@xxxxxxxxxx> wrote: >>>>> >>>>> On Wed, Jun 09, 2021 at 09:26:03AM +0000, Anand Khoje wrote: >>>>>> Hi Leon, >>>>> >>>>> Please don't do top-posting. >>>>> >>>>> >>>>>> >>>>>> The set_bit()/clear_bit() and enum ib_port_data_flags has been added as a device that can be used for future enhancements. >>>>>> Also, usage of set_bit()/clear_bit() ensures the operations on this bit is atomic. >>>>> >>>>> The bitfield variables are better suit this use case. >>>>> Let's don't overcomplicate code without the reason. >>>> >>>> The problem is always that people tend to build on what's in there. For example, look at the bitfields in rdma_id_private, tos_set, timeout_set, and min_rnr_timer_set. >>>> >>>> What do you think will happen when, let's say, rdma_set_service_type() and rdma_set_ack_timeout() are called in close proximity in time? There is no locking, and the RMW will fail intermittently. >>> >>> We are talking about device initialization flow that shouldn't be >>> performed in parallel to another initialization of same device, so the >>> comparison to rdma-cm is not valid here. >> >> I can agree to that. And it is probably not worthwhile to fix the bit-fields in rdma_id_private? > > Before this article [1], I would say no, we don't need to fix. > Now, I'm not sure about that. > > "He also notes that even though the design flaws are difficult to exploit > on their own, they can be combined with the other flaws found to make for > a much more serious problem." > > and > > "In other words, people did notice this vulnerability and a defense was standardized, > but in practice the defense was never adopted. This is a good example that security > defenses must be adopted before attacks become practical." Let me send you a commit tomorrow. The last sentence you quoted above is ambiguous as far as I can understand. But the intention is clear though :-) Thxs, Håkon
