RE: testmgr question

[Pascal Van Leeuwen <pvanleeuwen@insidesecure.com>]

> -----Original Message-----
> From: Eric Biggers [mailto:ebiggers@google.com]
> Sent: Thursday, May 23, 2019 9:06 PM
> To: Pascal Van Leeuwen <pvanleeuwen@insidesecure.com>
> Cc: linux-crypto-owner@vger.kernel.org; Herbert Xu
> <herbert@gondor.apana.org.au>
> Subject: Re: testmgr question
>
> On Thu, May 23, 2019 at 07:01:46AM +0000, Pascal Van Leeuwen wrote:
> > > -----Original Message-----
> > > From: Eric Biggers [mailto:ebiggers@google.com]
> > > Sent: Wednesday, May 22, 2019 6:28 PM
> > > To: Pascal Van Leeuwen <pvanleeuwen@insidesecure.com>
> > > Cc: linux-crypto-owner@vger.kernel.org; Herbert Xu
> > > <herbert@gondor.apana.org.au>
> > > Subject: Re: testmgr question
> > >
> > > On Wed, May 22, 2019 at 01:32:43PM +0000, Pascal Van Leeuwen wrote:
> > > > Ugh,
> > > >
> > > > I just synced my development branch with Linus' mainline tree (5.2-rc1)
> and
> > > > apparently inherited some new testmgr tests that are now failing on the
> > > Inside
> > > > Secure driver. I managed to fix some trivial ones related to non-zero
> IV
> > > size
> > > > on ECB modes and error codes that differed from the expected ones, but
> now
> > > I'm
> > > > rather stuck with a hang case ... and I don't have a clue which
> particular
> > > test
> > > > is hanging or even which algorithm is being tested :-(
> > > >
> > > > Is there, by any chance, some magical debug switch available to make
> > > testmgr
> > > > print out which test it is actually *starting* to run?
> > > >
> > > > Regards,
> > > >
> > > > Pascal van Leeuwen
> > > > Silicon IP Architect, Multi-Protocol Engines @ Inside Secure
> > > > www.insidesecure.com
> > > >
> > >
> > > Not currently, but you can easily add some debugging messages to testmgr
> > > yourself.  E.g.,
> > >
> > > Print 'alg' and 'driver' at beginning of alg_test() to see which
> algorithm is
> > > starting to be tested.
> > >
> > > Print 'vec_name' and 'cfg->name' at beginning of test_hash_vec_cfg(),
> > > test_skcipher_vec_cfg(), and test_aead_vec_cfg() to see which test vector
> is
> > > starting to be tested and under what configuration.
> > >
> > Thanks. I guess adding such debugging statements to testmgr is what I've
> been
> > doing all along. Like everyone else having to debug these issues, I guess
> ...
> > Therefore I assumed by now, there might have been some standard
> infrastructure
> > for that. Or maybe it was just a hint that such a thing might be useful ;-)
> >
>
> testmgr already prints information when a test fails which is enough for most
> cases, and in my experience when it's not I need to add messages specific to
> tracking down the particular issue anyway.  So that's why I haven't
> personally
> added more messages.  Feel free to send a patch, though.  Also, please
> continue
> any further discussion of this on linux-crypto.
>
When developing hardware drivers, when things go wrong, odds are fairly
significant that the whole thing just hangs (or is that just me? :-).
So I can imagine I'm not the only one adding these debug print statements,
which means effort is probably wasted here. But I do notice that I keep
adding and removing them/commenting them out as they're pretty annoying when
things don't actually hang ...

Usually just knowing which specific case fails is enough for me  to reason about
why it's failing. I rarely need more debugging information than that. Following
a hash/HMAC operation is pretty impossible anyway unless you have a reference
implementation standing by to compare with.

Regards,
Pascal van Leeuwen
Silicon IP Architect, Multi-Protocol Engines @ Inside Secure
www.insidesecure.com