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 --- drivers/md/dm-crypt.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'drivers/md/dm-crypt.c') diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index cdf6b1e12460..fa17e5452796 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -758,9 +758,8 @@ static int crypt_iv_tcw_whitening(struct crypt_config *cc, int i, r; /* xor whitening with sector number */ - memcpy(buf, tcw->whitening, TCW_WHITENING_SIZE); - crypto_xor(buf, (u8 *)§or, 8); - crypto_xor(&buf[8], (u8 *)§or, 8); + crypto_xor_cpy(buf, tcw->whitening, (u8 *)§or, 8); + crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)§or, 8); /* calculate crc32 for every 32bit part and xor it */ desc->tfm = tcw->crc32_tfm; @@ -805,10 +804,10 @@ static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv, } /* Calculate IV */ - memcpy(iv, tcw->iv_seed, cc->iv_size); - crypto_xor(iv, (u8 *)§or, 8); + crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)§or, 8); if (cc->iv_size > 8) - crypto_xor(&iv[8], (u8 *)§or, cc->iv_size - 8); + crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)§or, + cc->iv_size - 8); return r; } -- cgit v1.2.3