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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2017-07-24 13:28:04 +0300
committerHerbert Xu <herbert@gondor.apana.org.au>2017-08-04 04:27:15 +0300
commit45fe93dff2fb58b22de04c729f8447ba0f773d93 (patch)
tree6f6039696f88fb5461831d4bfbc4e62f059092d5 /drivers/md/dm-crypt.c
parenta7c391f04fe3259fb0417d71fec78ae28f25780e (diff)
downloadlinux-45fe93dff2fb58b22de04c729f8447ba0f773d93.tar.xz
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 <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/md/dm-crypt.c')
-rw-r--r--drivers/md/dm-crypt.c11
1 files changed, 5 insertions, 6 deletions
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 *)&sector, 8);
- crypto_xor(&buf[8], (u8 *)&sector, 8);
+ crypto_xor_cpy(buf, tcw->whitening, (u8 *)&sector, 8);
+ crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)&sector, 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 *)&sector, 8);
+ crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)&sector, 8);
if (cc->iv_size > 8)
- crypto_xor(&iv[8], (u8 *)&sector, cc->iv_size - 8);
+ crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)&sector,
+ cc->iv_size - 8);
return r;
}