[PATCH 4.9 03/72] [PATCH -stable] arm: crypto: reduce priority of bit-sliced AES cipher

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Biggers <ebiggers@xxxxxxxxxx>

[ 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 <ebiggers@xxxxxxxxxx>
Acked-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
 arch/arm/crypto/aesbs-glue.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- 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),