From 45fe93dff2fb58b22de04c729f8447ba0f773d93 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Mon, 24 Jul 2017 11:28:04 +0100 Subject: crypto: algapi - make crypto_xor() take separate dst and src arguments There are quite a number of occurrences in the kernel of the pattern if (dst != src) memcpy(dst, src, walk.total % AES_BLOCK_SIZE); crypto_xor(dst, final, walk.total % AES_BLOCK_SIZE); or crypto_xor(keystream, src, nbytes); memcpy(dst, keystream, nbytes); where crypto_xor() is preceded or followed by a memcpy() invocation that is only there because crypto_xor() uses its output parameter as one of the inputs. To avoid having to add new instances of this pattern in the arm64 code, which will be refactored to implement non-SIMD fallbacks, add an alternative implementation called crypto_xor_cpy(), taking separate input and output arguments. This removes the need for the separate memcpy(). Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu --- crypto/pcbc.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) (limited to 'crypto/pcbc.c') diff --git a/crypto/pcbc.c b/crypto/pcbc.c index 29dd2b4a3b85..d9e45a958720 100644 --- a/crypto/pcbc.c +++ b/crypto/pcbc.c @@ -55,8 +55,7 @@ static int crypto_pcbc_encrypt_segment(struct skcipher_request *req, do { crypto_xor(iv, src, bsize); crypto_cipher_encrypt_one(tfm, dst, iv); - memcpy(iv, dst, bsize); - crypto_xor(iv, src, bsize); + crypto_xor_cpy(iv, dst, src, bsize); src += bsize; dst += bsize; @@ -79,8 +78,7 @@ static int crypto_pcbc_encrypt_inplace(struct skcipher_request *req, memcpy(tmpbuf, src, bsize); crypto_xor(iv, src, bsize); crypto_cipher_encrypt_one(tfm, src, iv); - memcpy(iv, tmpbuf, bsize); - crypto_xor(iv, src, bsize); + crypto_xor_cpy(iv, tmpbuf, src, bsize); src += bsize; } while ((nbytes -= bsize) >= bsize); @@ -127,8 +125,7 @@ static int crypto_pcbc_decrypt_segment(struct skcipher_request *req, do { crypto_cipher_decrypt_one(tfm, dst, src); crypto_xor(dst, iv, bsize); - memcpy(iv, src, bsize); - crypto_xor(iv, dst, bsize); + crypto_xor_cpy(iv, dst, src, bsize); src += bsize; dst += bsize; @@ -153,8 +150,7 @@ static int crypto_pcbc_decrypt_inplace(struct skcipher_request *req, memcpy(tmpbuf, src, bsize); crypto_cipher_decrypt_one(tfm, src, src); crypto_xor(src, iv, bsize); - memcpy(iv, tmpbuf, bsize); - crypto_xor(iv, src, bsize); + crypto_xor_cpy(iv, src, tmpbuf, bsize); src += bsize; } while ((nbytes -= bsize) >= bsize); -- cgit v1.2.3-59-g8ed1b