From:   Stephan =?ISO-8859-1?Q?M=FCller?= <smueller@chronox.de>
To:     herbert@gondor.apana.org.au
Cc:     linux-crypto@vger.kernel.org
Subject: CRYPTO_NOLOAD
Date:   Tue, 11 Jan 2022 09:04:16 +0100
Message-ID: <2191439.vFx2qVVIhK@positron.chronox.de>
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Hi Herbert,

I am experimenting with additional flags like CRYPTO_NOLOAD. When I allocate 
an skcipher with this flag (crypto_alloc_skcipher("name", 0, CRYPTO_NOLOAD)), 
a loading of new modules is performed, in particular for subordinated algos 
(e.g. I try to load ctr(aes) which then in turn tries to resolve the AESNI 
implementation which in turn loads the cryptd() implementation).

The reason for this is function crypto_find_alg which clears out all flags 
that are not in maskset or maskclear.

For skcipher, this is defined as 

        .maskclear = ~CRYPTO_ALG_TYPE_MASK,
        .maskset = CRYPTO_ALG_TYPE_MASK,

Thus, the CRYPTO_NOLOAD flag is removed. How would I be able to allocate an 
algorithm without attempting to load modules?

Or phrasing the question differently: is there an issue to add CRYPTO_NOLOAD 
to the .maskclear and .maskset definitions, which would allocate the 
subordinate algos also with the NOLOAD flag?

Thanks a lot
Stephan