Date:   Tue, 11 Jan 2022 13:43:58 -0800
From:   Eric Biggers <ebiggers@kernel.org>
To:     Herbert Xu <herbert@gondor.apana.org.au>
Cc:     Linux Crypto Mailing List <linux-crypto@vger.kernel.org>
Subject: Re: [PATCH] crypto: testmgr - Move crypto_simd_disabled_for_test out
Message-ID: <Yd36HsgI+ya6P7RF@gmail.com>
References: <Yd0jA4VOjysrdOu7@gondor.apana.org.au>
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On Tue, Jan 11, 2022 at 05:26:11PM +1100, Herbert Xu wrote:
> As testmgr is part of cryptomgr which was designed to be unloadable
> as a module, it shouldn't export any symbols for other crypto
> modules to use as that would prevent it from being unloaded.  All
> its functionality is meant to be accessed through notifiers.
> 
> The symbol crypto_simd_disabled_for_test was added to testmgr
> which caused it to be pinned as a module if its users were also
> loaded.  This patch moves it out of testmgr and into crypto/simd.c
> so cryptomgr can again be unloaded and replaced on demand.
> 
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
> 
> diff --git a/crypto/simd.c b/crypto/simd.c
> index edaa479a1ec5..2027d747b746 100644
> --- a/crypto/simd.c
> +++ b/crypto/simd.c
> @@ -47,6 +47,11 @@ struct simd_skcipher_ctx {
>  	struct cryptd_skcipher *cryptd_tfm;
>  };
>  
> +#ifdef CONFIG_CRYPTO_MANAGER_EXTRA_TESTS
> +DEFINE_PER_CPU(bool, crypto_simd_disabled_for_test);
> +EXPORT_PER_CPU_SYMBOL_GPL(crypto_simd_disabled_for_test);
> +#endif
> +
>  static int simd_skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
>  				unsigned int key_len)
>  {

It doesn't look like all the users of crypto_simd_usable() select CRYPTO_SIMD.
So this will cause a build break in some configurations.

Maybe CRYPTO_MANAGER_EXTRA_TESTS should select CRYPTO_SIMD?

- Eric