LTP: crypto: af_alg02 regression on linux-next 20200621 tag

[Eric Biggers]

On Tue, Jun 23, 2020 at 04:40:56PM +1000, Herbert Xu wrote:
> On Tue, Jun 23, 2020 at 11:53:43AM +0530, Naresh Kamboju wrote:
> >
> > Thanks for the investigation.
> > After reverting, two test cases got PASS out of four reported failure cases.
> >  ltp-crypto-tests:
> >      * af_alg02 - still failing - Hung and time out
> >      * af_alg05 - still failing - Hung and time out
> >   ltp-syscalls-tests:
> >      * keyctl07 - PASS
> >      * request_key03 - PASS
> > 
> > Please suggest the way to debug / fix the af_alg02 and af_alg05 failures.
> 
> Did you clear the MSG_MORE flag in the final send(2) call before
> you call recv(2)?
> 

The source code for the two failing AF_ALG tests is here:

https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/crypto/af_alg02.c
https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/crypto/af_alg05.c

They use read() and write(), not send() and recv().

af_alg02 uses read() to read from a "salsa20" request socket without writing
anything to it.  It is expected that this returns 0, i.e. that behaves like
encrypting an empty message.

af_alg05 uses write() to write 15 bytes to a "cbc(aes-generic)" request socket,
then read() to read 15 bytes.  It is expected that this fails with EINVAL, since
the length is not aligned to the AES block size (16 bytes).

- Eric