• Ard Biesheuvel's avatar
    crypto: algapi - make crypto_xor() take separate dst and src arguments · 45fe93df
    Ard Biesheuvel authored
    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: 's avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
    Signed-off-by: 's avatarHerbert Xu <herbert@gondor.apana.org.au>
    45fe93df