Re: [PATCH 2/3] crypto: inside-secure: add EIP93 ESP packet backend

[Jihong Min <hurryman2212@gmail.com>]

On 5/27/26 19:08, Simon Horman wrote:
> On Sat, May 23, 2026 at 09:15:21PM +0900, Jihong Min wrote:
>> Expose an EIP93 packet-mode IPsec backend for netdev drivers that need
>> ESP encapsulation and decapsulation offload without advertising EIP93
>> itself as a netdev.
>>
>> Add provider selection, capability reporting, SA lifecycle management,
>> IPsec request completion, and provider fault notification around the
>> existing EIP93 descriptor path.
>>
>> Assisted-by: Codex:gpt-5.5
>> Signed-off-by: Jihong Min <hurryman2212@gmail.com>
> 
> ...
> 
>> diff --git a/drivers/crypto/inside-secure/eip93/eip93-ipsec.c b/drivers/crypto/inside-secure/eip93/eip93-ipsec.c
> 
> ...
> 
>> +static void eip93_ipsec_abort_requests(struct eip93_ipsec *ipsec, int err)
>> +{
>> +	struct eip93_ipsec_sa *sa;
>> +
>> +	while (true) {
>> +		bool found = false;
>> +
>> +		spin_lock_bh(&ipsec->lock);
>> +		list_for_each_entry(sa, &ipsec->sa_list, node) {
>> +			spin_lock(&sa->lock);
>> +			if (sa->aborting) {
>> +				spin_unlock(&sa->lock);
>> +				continue;
>> +			}
>> +
>> +			sa->aborting = true;
>> +			found = refcount_inc_not_zero(&sa->refcnt);
>> +			spin_unlock(&sa->lock);
>> +			if (found)
>> +				break;
>> +		}
>> +		spin_unlock_bh(&ipsec->lock);
>> +		if (!found)
>> +			return;
>> +
>> +		eip93_ipsec_abort_sa(sa, err);
>> +		eip93_ipsec_sa_put(sa);
> 
> sa is the iterator for the list_for_each_entry loop.
> However, here it is used outside of that context.
> 
> 	"If list_for_each_entry, etc complete a traversal of the list, the
> 	iterator variable ends up pointing to an address at an offset from
> 	the list head, and not a meaningful structure.  Thus this value
> 	should not be used after the end of the iterator.
> 
> 	https://www.spinics.net/lists/linux-kernel-janitors/msg11994.html
> 
> Flagged by Coccinelle.
> 

Hi Simon,

Thanks for the feedback, and sorry for noticing this mail so late.

Your point is correct. The `list_for_each_entry()` iterator should not
be used outside the loop like that. If I continued with this series, I
would fix it by keeping a separate selected SA pointer before dropping
the lock.

At this point, though, I think the right thing is to withdraw this
EIP93/Airoha series.

The reason is that many Airoha SoCs also have a higher-performance IP
block called SOE (Secure Offload Engine). I recently wrote and tested a
driver for that block, and I am currently carrying it here: [kernel: add
bonding LAG XFRM offload infrastructure and Airoha
support](https://github.com/hurryman2212/OpenW1700k-test/commit/fbfe8f919f836bb62b3849f803865a4d9b8dc76f).
With the EIP93 path I could get around 1 Gbps, while the SOE path can
reach about 5 Gbps in my current setup. Because of that, integrating
this EIP93 ESP packet path directly into `airoha_eth` is no longer the
most useful direction for Airoha Ethernet.

That said, SOE exists only on some Airoha SoCs. EIP93 can still be
useful on other platforms as a look-aside ESP packet offloader, but I
think that needs a cleaner infrastructure than this series had. The
look-aside offloader should be able to live as a separate module, not be
tied directly to one specific netdev driver, while still allowing
compatible netdevs to attach it into the XFRM path. I think that needs a
more general infrastructure extension, so I would rather revisit the
EIP93 work later on top of that kind of model.


Sincerely,
Jihong Min

>> +	}
>> +}
> 
> ...