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>

9 files changed, 12 insertions, 22 deletions

diff --git a/arch/arm/crypto/aes-ce-glue.c b/arch/arm/crypto/aes-ce-glue.c
index 0f966a8ca1ce..d0a9cec73707 100644
--- a/arch/arm/crypto/aes-ce-glue.c
+++ b/arch/arm/crypto/aes-ce-glue.c
@@ -285,9 +285,7 @@ static int ctr_encrypt(struct skcipher_request *req)
 
 		ce_aes_ctr_encrypt(tail, NULL, (u8 *)ctx->key_enc,
 				   num_rounds(ctx), blocks, walk.iv);
-		if (tdst != tsrc)
-			memcpy(tdst, tsrc, nbytes);
-		crypto_xor(tdst, tail, nbytes);
+		crypto_xor_cpy(tdst, tsrc, tail, nbytes);
 		err = skcipher_walk_done(&walk, 0);
 	}
 	kernel_neon_end();
diff --git a/arch/arm/crypto/aes-neonbs-glue.c b/arch/arm/crypto/aes-neonbs-glue.c
index c76377961444..18768f330449 100644
--- a/arch/arm/crypto/aes-neonbs-glue.c
+++ b/arch/arm/crypto/aes-neonbs-glue.c
@@ -221,9 +221,8 @@ static int ctr_encrypt(struct skcipher_request *req)
 			u8 *dst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
 			u8 *src = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;
 
-			if (dst != src)
-				memcpy(dst, src, walk.total % AES_BLOCK_SIZE);
-			crypto_xor(dst, final, walk.total % AES_BLOCK_SIZE);
+			crypto_xor_cpy(dst, src, final,
+				       walk.total % AES_BLOCK_SIZE);
 
 			err = skcipher_walk_done(&walk, 0);
 			break;
diff --git a/arch/arm64/crypto/aes-glue.c b/arch/arm64/crypto/aes-glue.c
index bcf596b0197e..0da30e3b0e4b 100644
--- a/arch/arm64/crypto/aes-glue.c
+++ b/arch/arm64/crypto/aes-glue.c
@@ -241,9 +241,7 @@ static int ctr_encrypt(struct skcipher_request *req)
 
 		aes_ctr_encrypt(tail, NULL, (u8 *)ctx->key_enc, rounds,
 				blocks, walk.iv, first);
-		if (tdst != tsrc)
-			memcpy(tdst, tsrc, nbytes);
-		crypto_xor(tdst, tail, nbytes);
+		crypto_xor_cpy(tdst, tsrc, tail, nbytes);
 		err = skcipher_walk_done(&walk, 0);
 	}
 	kernel_neon_end();
diff --git a/arch/arm64/crypto/aes-neonbs-glue.c b/arch/arm64/crypto/aes-neonbs-glue.c
index db2501d93550..9001aec16007 100644
--- a/arch/arm64/crypto/aes-neonbs-glue.c
+++ b/arch/arm64/crypto/aes-neonbs-glue.c
@@ -224,9 +224,8 @@ static int ctr_encrypt(struct skcipher_request *req)
 			u8 *dst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
 			u8 *src = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;
 
-			if (dst != src)
-				memcpy(dst, src, walk.total % AES_BLOCK_SIZE);
-			crypto_xor(dst, final, walk.total % AES_BLOCK_SIZE);
+			crypto_xor_cpy(dst, src, final,
+				       walk.total % AES_BLOCK_SIZE);
 
 			err = skcipher_walk_done(&walk, 0);
 			break;
diff --git a/arch/sparc/crypto/aes_glue.c b/arch/sparc/crypto/aes_glue.c
index c90930de76ba..3cd4f6b198b6 100644
--- a/arch/sparc/crypto/aes_glue.c
+++ b/arch/sparc/crypto/aes_glue.c
@@ -344,8 +344,7 @@ static void ctr_crypt_final(struct crypto_sparc64_aes_ctx *ctx,
 
 	ctx->ops->ecb_encrypt(&ctx->key[0], (const u64 *)ctrblk,
 			      keystream, AES_BLOCK_SIZE);
-	crypto_xor((u8 *) keystream, src, nbytes);
-	memcpy(dst, keystream, nbytes);
+	crypto_xor_cpy(dst, (u8 *) keystream, src, nbytes);
 	crypto_inc(ctrblk, AES_BLOCK_SIZE);
 }
 
diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index 4a55cdcdc008..5c15d6b57329 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -475,8 +475,8 @@ static void ctr_crypt_final(struct crypto_aes_ctx *ctx,
 	unsigned int nbytes = walk->nbytes;
 
 	aesni_enc(ctx, keystream, ctrblk);
-	crypto_xor(keystream, src, nbytes);
-	memcpy(dst, keystream, nbytes);
+	crypto_xor_cpy(dst, keystream, src, nbytes);
+
 	crypto_inc(ctrblk, AES_BLOCK_SIZE);
 }
 
diff --git a/arch/x86/crypto/blowfish_glue.c b/arch/x86/crypto/blowfish_glue.c
index 17c05531dfd1..f9eca34301e2 100644
--- a/arch/x86/crypto/blowfish_glue.c
+++ b/arch/x86/crypto/blowfish_glue.c
@@ -271,8 +271,7 @@ static void ctr_crypt_final(struct bf_ctx *ctx, struct blkcipher_walk *walk)
 	unsigned int nbytes = walk->nbytes;
 
 	blowfish_enc_blk(ctx, keystream, ctrblk);
-	crypto_xor(keystream, src, nbytes);
-	memcpy(dst, keystream, nbytes);
+	crypto_xor_cpy(dst, keystream, src, nbytes);
 
 	crypto_inc(ctrblk, BF_BLOCK_SIZE);
 }
diff --git a/arch/x86/crypto/cast5_avx_glue.c b/arch/x86/crypto/cast5_avx_glue.c
index 8648158f3916..dbea6020ffe7 100644
--- a/arch/x86/crypto/cast5_avx_glue.c
+++ b/arch/x86/crypto/cast5_avx_glue.c
@@ -256,8 +256,7 @@ static void ctr_crypt_final(struct blkcipher_desc *desc,
 	unsigned int nbytes = walk->nbytes;
 
 	__cast5_encrypt(ctx, keystream, ctrblk);
-	crypto_xor(keystream, src, nbytes);
-	memcpy(dst, keystream, nbytes);
+	crypto_xor_cpy(dst, keystream, src, nbytes);
 
 	crypto_inc(ctrblk, CAST5_BLOCK_SIZE);
 }
diff --git a/arch/x86/crypto/des3_ede_glue.c b/arch/x86/crypto/des3_ede_glue.c
index d6fc59aaaadf..30c0a37f4882 100644
--- a/arch/x86/crypto/des3_ede_glue.c
+++ b/arch/x86/crypto/des3_ede_glue.c
@@ -277,8 +277,7 @@ static void ctr_crypt_final(struct des3_ede_x86_ctx *ctx,
 	unsigned int nbytes = walk->nbytes;
 
 	des3_ede_enc_blk(ctx, keystream, ctrblk);
-	crypto_xor(keystream, src, nbytes);
-	memcpy(dst, keystream, nbytes);
+	crypto_xor_cpy(dst, keystream, src, nbytes);
 
 	crypto_inc(ctrblk, DES3_EDE_BLOCK_SIZE);
 }