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Date:   Fri, 19 Aug 2022 17:40:30 -0700
From:   Eric Biggers <ebiggers@kernel.org>
To:     "Elliott, Robert (Servers)" <elliott@hpe.com>
Cc:     Herbert Xu <herbert@gondor.apana.org.au>,
        "tim.c.chen@linux.intel.com" <tim.c.chen@linux.intel.com>,
        "davem@davemloft.net" <davem@davemloft.net>,
        "linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
        "Kani, Toshi" <toshi.kani@hpe.com>,
        "Wright, Randy (HPE Servers Linux)" <rwright@hpe.com>
Subject: Re: [PATCH] crypto: testmgr - don't generate WARN for missing modules
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On Sat, Aug 20, 2022 at 12:15:41AM +0000, Elliott, Robert (Servers) wrote:
> Per Stephan, it sounds like this was a hacky way to get some/most of
> the modules loaded.
> 
> It'd be good if there was a way to run all registered tests on all
> available modules, not just the ones that someone remembered to put
> in tcrypt.c.

Most algorithms can be allocated via a userspace program using AF_ALG.  The only
exception is algorithm types that AF_ALG doesn't support.

> I do worry this WARN() isn't really helpful even for real self-test
> failures - it's dumping the call trace to alg_test(), not the
> trace to whatever crypto function alg_test called that is failing. 
> With Linus always expressing concern with too many BUG and WARN
> calls, it might be better as just pr_warn() or pr_err().

It's very helpful because WARN is the standard way for the kernel to report that
a kernel bug has been encountered.  A test failure is a kernel bug.

The stack trace printed by WARN indeed isn't useful here, as it will always be
the same.  But it's just a side effect.  The important things here are that a
WARN is triggered at all, and that some log messages that describe what failed
are printed.

- Eric