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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2017-07-24 12:28:04 +0200
committerHerbert Xu <herbert@gondor.apana.org.au>2017-08-04 03:27:15 +0200
commit45fe93dff2fb58b22de04c729f8447ba0f773d93 (patch)
tree6f6039696f88fb5461831d4bfbc4e62f059092d5 /crypto/ctr.c
parentcrypto: algapi - use separate dst and src operands for __crypto_xor() (diff)
downloadlinux-45fe93dff2fb58b22de04c729f8447ba0f773d93.tar.xz
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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 'crypto/ctr.c')
-rw-r--r--crypto/ctr.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/crypto/ctr.c b/crypto/ctr.c
index 477d9226ccaa..854d924f9d8e 100644
--- a/crypto/ctr.c
+++ b/crypto/ctr.c
@@ -65,8 +65,7 @@ static void crypto_ctr_crypt_final(struct blkcipher_walk *walk,
unsigned int nbytes = walk->nbytes;
crypto_cipher_encrypt_one(tfm, keystream, ctrblk);
- crypto_xor(keystream, src, nbytes);
- memcpy(dst, keystream, nbytes);
+ crypto_xor_cpy(dst, keystream, src, nbytes);
crypto_inc(ctrblk, bsize);
}