Re: [PATCH v10 2/3] crypto: ti - Add support for AES-GCM in DTHEv2 driver

[T Pratham <t-pratham@ti.com>]

On 07-03-2026 10:53, Herbert Xu wrote:
> On Thu, Feb 26, 2026 at 06:24:40PM +0530, T Pratham wrote:
>>
>> +	src = dthe_aead_prep_src(req->src, req->assoclen, cryptlen,
>> +				 src_assoc_padbuf, src_crypt_padbuf);
>> +	if (IS_ERR(src)) {
>> +		ret = PTR_ERR(src);
>> +		goto aead_prep_src_err;
>> +	}
>> +
>> +	if (req->assoclen % AES_BLOCK_SIZE)
>> +		assoclen += AES_BLOCK_SIZE - (req->assoclen % AES_BLOCK_SIZE);
>> +	if (cryptlen % AES_BLOCK_SIZE)
>> +		cryptlen += AES_BLOCK_SIZE - (cryptlen % AES_BLOCK_SIZE);
>> +
>> +	src_nents = sg_nents_for_len(src, assoclen + cryptlen);
>> +
>> +	if (cryptlen != 0) {
>> +		dst = dthe_aead_prep_dst(req->dst, req->assoclen, unpadded_cryptlen,
>> +					 dst_crypt_padbuf);
>> +		if (IS_ERR(dst)) {
>> +			ret = PTR_ERR(dst);
>> +			goto aead_prep_dst_err;
>> +		}
>> +
>> +		dst_nents = sg_nents_for_len(dst, cryptlen);
>> +	}
>> +	/* Prep finished */
> 
> How does this handle the case where req->src == req->dst?

What potential issue do you see? Both `dthe_aead_prep_src` and
`dthe_prep_aead_dst` functions use `sg_split`, which anyway allocates a
new scatterlist. Even if req->src == req->dst, the src and dst from here
on will be different.

-- 
Regards
T Pratham <t-pratham@ti.com>