crypto: x86/aesni - Correct the data type in struct aesni_xts_ctx

Currently, every field in struct aesni_xts_ctx is defined as a byte
array of the same size as struct crypto_aes_ctx. This data type
is obscure and the choice lacks justification.

To rectify this, update the field type in struct aesni_xts_ctx to
match its actual structure.
Suggested-by: Eric Biggers <ebiggers@kernel.org>
Link: https://lore.kernel.org/all/ZFWQ4sZEVu%2FLHq+Q@gmail.com/Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Cc: linux-crypto@vger.kernel.org
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

arch/x86/crypto/aesni-intel_glue.c

@@ -61,8 +61,8 @@ struct generic_gcmaes_ctx {
 };
 
 struct aesni_xts_ctx {
-	u8 raw_tweak_ctx[sizeof(struct crypto_aes_ctx)] AESNI_ALIGN_ATTR;
-	u8 raw_crypt_ctx[sizeof(struct crypto_aes_ctx)] AESNI_ALIGN_ATTR;
+	struct crypto_aes_ctx tweak_ctx AESNI_ALIGN_ATTR;
+	struct crypto_aes_ctx crypt_ctx AESNI_ALIGN_ATTR;
 };
 
 #define GCM_BLOCK_LEN 16
@@ -885,13 +885,12 @@ static int xts_aesni_setkey(struct crypto_skcipher *tfm, const u8 *key,
 	keylen /= 2;
 
 	/* first half of xts-key is for crypt */
-	err = aes_set_key_common(aes_ctx(ctx->raw_crypt_ctx), key, keylen);
+	err = aes_set_key_common(aes_ctx(&ctx->crypt_ctx), key, keylen);
 	if (err)
 		return err;
 
 	/* second half of xts-key is for tweak */
-	return aes_set_key_common(aes_ctx(ctx->raw_tweak_ctx), key + keylen,
-				  keylen);
+	return aes_set_key_common(aes_ctx(&ctx->tweak_ctx), key + keylen, keylen);
 }
 
 static int xts_crypt(struct skcipher_request *req, bool encrypt)
@@ -933,7 +932,7 @@ static int xts_crypt(struct skcipher_request *req, bool encrypt)
 	kernel_fpu_begin();
 
 	/* calculate first value of T */
-	aesni_enc(aes_ctx(ctx->raw_tweak_ctx), walk.iv, walk.iv);
+	aesni_enc(aes_ctx(&ctx->tweak_ctx), walk.iv, walk.iv);
 
 	while (walk.nbytes > 0) {
 		int nbytes = walk.nbytes;
@@ -942,11 +941,11 @@ static int xts_crypt(struct skcipher_request *req, bool encrypt)
 			nbytes &= ~(AES_BLOCK_SIZE - 1);
 
 		if (encrypt)
-			aesni_xts_encrypt(aes_ctx(ctx->raw_crypt_ctx),
+			aesni_xts_encrypt(aes_ctx(&ctx->crypt_ctx),
 					  walk.dst.virt.addr, walk.src.virt.addr,
 					  nbytes, walk.iv);
 		else
-			aesni_xts_decrypt(aes_ctx(ctx->raw_crypt_ctx),
+			aesni_xts_decrypt(aes_ctx(&ctx->crypt_ctx),
 					  walk.dst.virt.addr, walk.src.virt.addr,
 					  nbytes, walk.iv);
 		kernel_fpu_end();
@@ -974,11 +973,11 @@ static int xts_crypt(struct skcipher_request *req, bool encrypt)
 
 		kernel_fpu_begin();
 		if (encrypt)
-			aesni_xts_encrypt(aes_ctx(ctx->raw_crypt_ctx),
+			aesni_xts_encrypt(aes_ctx(&ctx->crypt_ctx),
 					  walk.dst.virt.addr, walk.src.virt.addr,
 					  walk.nbytes, walk.iv);
 		else
-			aesni_xts_decrypt(aes_ctx(ctx->raw_crypt_ctx),
+			aesni_xts_decrypt(aes_ctx(&ctx->crypt_ctx),
 					  walk.dst.virt.addr, walk.src.virt.addr,
 					  walk.nbytes, walk.iv);
 		kernel_fpu_end();