From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Henrique Cerri Subject: [PATCH 2/2] crypto: ctr - Propagate NEED_FALLBACK bit Date: Sun, 26 Feb 2017 22:03:19 -0300 Message-ID: <1488157399-3587-3-git-send-email-marcelo.cerri@canonical.com> References: <1488157399-3587-1-git-send-email-marcelo.cerri@canonical.com> Cc: "David S. Miller" , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, Marcelo Henrique Cerri To: Herbert Xu Return-path: In-Reply-To: <1488157399-3587-1-git-send-email-marcelo.cerri@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org When requesting a fallback algorithm, we should propagate the NEED_FALLBACK bit when search for the underlying algorithm. This will prevents drivers from allocating unnecessary fallbacks that are never called. For instance, currently the vmx-crypto driver will use the following chain of calls when calling the fallback implementation: p8_aes_ctr -> ctr(p8_aes) -> aes-generic However p8_aes will always delegate its calls to aes-generic. With this patch, p8_aes_ctr will be able to use ctr(aes-generic) directly as its fallback. The same applies to aes_s390. Signed-off-by: Marcelo Henrique Cerri --- crypto/ctr.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/crypto/ctr.c b/crypto/ctr.c index a4f4a89..3afe21a 100644 --- a/crypto/ctr.c +++ b/crypto/ctr.c @@ -181,15 +181,24 @@ static void crypto_ctr_exit_tfm(struct crypto_tfm *tfm) static struct crypto_instance *crypto_ctr_alloc(struct rtattr **tb) { struct crypto_instance *inst; + struct crypto_attr_type *algt; struct crypto_alg *alg; + u32 mask; int err; err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER); if (err) return ERR_PTR(err); - alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER, - CRYPTO_ALG_TYPE_MASK); + algt = crypto_get_attr_type(tb); + if (IS_ERR(algt)) + return PTR_ERR(algt); + + mask = CRYPTO_ALG_TYPE_MASK | + crypto_requires_off(algt->type, algt->mask, + CRYPTO_ALG_NEED_FALLBACK); + + alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER, mask); if (IS_ERR(alg)) return ERR_CAST(alg); -- 2.7.4