crypto: x86/aesni - Perform address alignment early for XTS mode

Currently, the alignment of each field in struct aesni_xts_ctx occurs
right before every access. However, it's possible to perform this
alignment ahead of time.

Introduce a helper function that converts struct crypto_skcipher *tfm
to struct aesni_xts_ctx *ctx and returns an aligned address. Utilize
this helper function at the beginning of each XTS function and then
eliminate redundant alignment code.

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>

diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index 80e28a0..b1d90c2 100644 (file)
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -223,6 +223,11 @@ static inline struct crypto_aes_ctx *aes_ctx(void *raw_ctx)
        return aes_align_addr(raw_ctx);
 }
 
+static inline struct aesni_xts_ctx *aes_xts_ctx(struct crypto_skcipher *tfm)
+{
+       return aes_align_addr(crypto_skcipher_ctx(tfm));
+}
+
 static int aes_set_key_common(struct crypto_aes_ctx *ctx,
                              const u8 *in_key, unsigned int key_len)
 {
@@ -875,7 +880,7 @@ static int helper_rfc4106_decrypt(struct aead_request *req)
 static int xts_aesni_setkey(struct crypto_skcipher *tfm, const u8 *key,
                            unsigned int keylen)
 {
-       struct aesni_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
+       struct aesni_xts_ctx *ctx = aes_xts_ctx(tfm);
        int err;
 
        err = xts_verify_key(tfm, key, keylen);
@@ -885,18 +890,18 @@ 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->crypt_ctx), key, keylen);
+       err = aes_set_key_common(&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->tweak_ctx), key + keylen, keylen);
+       return aes_set_key_common(&ctx->tweak_ctx, key + keylen, keylen);
 }
 
 static int xts_crypt(struct skcipher_request *req, bool encrypt)
 {
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
-       struct aesni_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
+       struct aesni_xts_ctx *ctx = aes_xts_ctx(tfm);
        int tail = req->cryptlen % AES_BLOCK_SIZE;
        struct skcipher_request subreq;
        struct skcipher_walk walk;
@@ -932,7 +937,7 @@ static int xts_crypt(struct skcipher_request *req, bool encrypt)
        kernel_fpu_begin();
 
        /* calculate first value of T */
-       aesni_enc(aes_ctx(&ctx->tweak_ctx), walk.iv, walk.iv);
+       aesni_enc(&ctx->tweak_ctx, walk.iv, walk.iv);
 
        while (walk.nbytes > 0) {
                int nbytes = walk.nbytes;
@@ -941,11 +946,11 @@ static int xts_crypt(struct skcipher_request *req, bool encrypt)
                        nbytes &= ~(AES_BLOCK_SIZE - 1);
 
                if (encrypt)
-                       aesni_xts_encrypt(aes_ctx(&ctx->crypt_ctx),
+                       aesni_xts_encrypt(&ctx->crypt_ctx,
                                          walk.dst.virt.addr, walk.src.virt.addr,
                                          nbytes, walk.iv);
                else
-                       aesni_xts_decrypt(aes_ctx(&ctx->crypt_ctx),
+                       aesni_xts_decrypt(&ctx->crypt_ctx,
                                          walk.dst.virt.addr, walk.src.virt.addr,
                                          nbytes, walk.iv);
                kernel_fpu_end();
@@ -973,11 +978,11 @@ static int xts_crypt(struct skcipher_request *req, bool encrypt)
 
                kernel_fpu_begin();
                if (encrypt)
-                       aesni_xts_encrypt(aes_ctx(&ctx->crypt_ctx),
+                       aesni_xts_encrypt(&ctx->crypt_ctx,
                                          walk.dst.virt.addr, walk.src.virt.addr,
                                          walk.nbytes, walk.iv);
                else
-                       aesni_xts_decrypt(aes_ctx(&ctx->crypt_ctx),
+                       aesni_xts_decrypt(&ctx->crypt_ctx,
                                          walk.dst.virt.addr, walk.src.virt.addr,
                                          walk.nbytes, walk.iv);
                kernel_fpu_end();