On Fri, Jun 16, 2017 at 07:57:00AM +0000, Horia Geantă wrote:
>
> Commit 0605c41cc53ca ("crypto: cts - Convert to skcipher") appends
> CRYPTO_TFM_REQ_MAY_BACKLOG to the original crypto request flags for the
> last block - when calling cts_cbc_encrypt().
> Is it really needed?Yes, because at this point we cannot tell the sender to back off. > For cts(cbc(aes)) with cbc(aes) offloaded in HW, i.e. running in async > mode, we get the below stack for CAAM driver. > Driver is told that it can sleep (CRYPTO_TFM_REQ_MAY_BACKLOG flag), so > it uses GFP_KERNEL to allocate memory. However, this is incorrect, since > driver runs in atomic context (softirq). This is wrong. Whether you can sleep or not is determined by MAY_SLEEP, not MAY_BACKLOG. MAY_BACKLOG only indicates that this request must be queued, even if the queue is full. Cheers, -- Email: Herbert Xu <herb...@gondor.apana.org.au> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
