crypto: aesni - fix XTS mode on x86-32, add wrapper function for asmlinkage aesni_enc()

Calling convention for internal functions and 'asmlinkage' functions is
different on x86-32. Therefore do not directly cast aesni_enc as XTS tweak
function, but use wrapper function in between. Fixes crash with "XTS +
aesni_intel + x86-32" combination.

Cc: stable@vger.kernel.org
Reported-by: Krzysztof Kolasa <kkolasa@winsoft.pl>
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/x86/crypto/aesni-intel_glue.c

@@ -515,6 +515,11 @@ static int xts_aesni_setkey(struct crypto_tfm *tfm, const u8 *key,
 }
 
 
+static void aesni_xts_tweak(void *ctx, u8 *out, const u8 *in)
+{
+	aesni_enc(ctx, out, in);
+}
+
 static int xts_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 		       struct scatterlist *src, unsigned int nbytes)
 {
@@ -525,7 +530,7 @@ static int xts_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 		.tbuflen = sizeof(buf),
 
 		.tweak_ctx = aes_ctx(ctx->raw_tweak_ctx),
-		.tweak_fn = XTS_TWEAK_CAST(aesni_enc),
+		.tweak_fn = aesni_xts_tweak,
 		.crypt_ctx = aes_ctx(ctx->raw_crypt_ctx),
 		.crypt_fn = lrw_xts_encrypt_callback,
 	};
@@ -550,7 +555,7 @@ static int xts_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 		.tbuflen = sizeof(buf),
 
 		.tweak_ctx = aes_ctx(ctx->raw_tweak_ctx),
-		.tweak_fn = XTS_TWEAK_CAST(aesni_enc),
+		.tweak_fn = aesni_xts_tweak,
 		.crypt_ctx = aes_ctx(ctx->raw_crypt_ctx),
 		.crypt_fn = lrw_xts_decrypt_callback,
 	};