From a5bd3edda619965bdaeb198f49b3713b4051ef39 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Fri, 17 Nov 2017 11:50:27 -0800 Subject: [PATCH] arm: crypto: reduce priority of bit-sliced AES cipher [ Not upstream because this is a minimal fix for a bug where arm32 kernels can use a much slower implementation of AES than is actually available, potentially forcing vendors to disable encryption on their devices.] All the aes-bs (bit-sliced) and aes-ce (cryptographic extensions) algorithms had a priority of 300. This is undesirable because it means an aes-bs algorithm may be used when an aes-ce algorithm is available. The aes-ce algorithms have much better performance (up to 10x faster). Fix it by decreasing the priority of the aes-bs algorithms to 250. This was fixed upstream by commit cc477bf64573 ("crypto: arm/aes - replace bit-sliced OpenSSL NEON code"), but it was just a small part of a complete rewrite. This patch just fixes the priority bug for older kernels. Signed-off-by: Eric Biggers Acked-by: Ard Biesheuvel --- arch/arm/crypto/aesbs-glue.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm/crypto/aesbs-glue.c b/arch/arm/crypto/aesbs-glue.c index 0511a6cafe24..5d934a0039d7 100644 --- a/arch/arm/crypto/aesbs-glue.c +++ b/arch/arm/crypto/aesbs-glue.c @@ -363,7 +363,7 @@ static struct crypto_alg aesbs_algs[] = { { }, { .cra_name = "cbc(aes)", .cra_driver_name = "cbc-aes-neonbs", - .cra_priority = 300, + .cra_priority = 250, .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC, .cra_blocksize = AES_BLOCK_SIZE, .cra_ctxsize = sizeof(struct async_helper_ctx), @@ -383,7 +383,7 @@ static struct crypto_alg aesbs_algs[] = { { }, { .cra_name = "ctr(aes)", .cra_driver_name = "ctr-aes-neonbs", - .cra_priority = 300, + .cra_priority = 250, .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC, .cra_blocksize = 1, .cra_ctxsize = sizeof(struct async_helper_ctx), @@ -403,7 +403,7 @@ static struct crypto_alg aesbs_algs[] = { { }, { .cra_name = "xts(aes)", .cra_driver_name = "xts-aes-neonbs", - .cra_priority = 300, + .cra_priority = 250, .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC, .cra_blocksize = AES_BLOCK_SIZE, .cra_ctxsize = sizeof(struct async_helper_ctx), -- 2.17.1