From patchwork Sat Apr 20 05:54:55 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 790554 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B5A9F2563 for ; Sat, 20 Apr 2024 05:55:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713592520; cv=none; b=pIQMpv9Dw1o1CvqWSQhVjJ0nMa4AztWW4hqMHlyr0RjzIcTvHKs4n1bcV3hFGXUUiHsir47GHLbxYpCftEdBChIHqYZosmnLMtObYjMAnwbmYdKSxT3geSIFnojS63AAXLp9f+R3pZ4X5AyrtlFmnsK/YqSB4YpLVh9qChI2Bgs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713592520; c=relaxed/simple; bh=LTc0gFb4N2F95I5oWv+o2EIp3INIrFlpfFLvrZi6GgE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=ZqciakYy8EylySkqlVcwM4gN4FBeMFA1IkmW4pXLYL6NKYQP5pxbRJacJ5X7ig5oh82HnnhCwXV0BMv9Um9mlB9o8XgRnajjDfGkBaz6w0qXJClA7CGIZjtZ6CJ99c9H2p3XfY5IF4wp3zQPK9DSYV/NU7WAoUxXxAyHrrNHzGA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KIvF8efd; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="KIvF8efd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0DA4DC072AA; Sat, 20 Apr 2024 05:55:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713592520; bh=LTc0gFb4N2F95I5oWv+o2EIp3INIrFlpfFLvrZi6GgE=; h=From:To:Cc:Subject:Date:From; b=KIvF8efdSEvuFm2BjphUJ9fzej9/stSng1sXnJp+NhTekeFgxAYtY/ZwAK/dNaHza aYB4WV5hXV91JG5RxeUT0kp1REsnQllTWnaSMWzAojmwYwLDMhrnxHevUshHtawCAt ChoGtAIEcY5zQAkarxsDuji+9aAui1YnYlTDNBniCnYe8YNhZWf4ukZPtKjdxCvGmw DKGn+DSednX0nWkDVVPnFM2WzIuSuqgskr4GJkxMrZgAshUyg3Uo8Kk9TvFiAngIUz VT8lpOz1gR1i/8P8d5yaO5W71Kgz8Q3Wi+Q7Eh2uvLbG2zNnxoSdQngmYqVFvjSQVX LXCazZ0GoGT3A== From: Eric Biggers To: linux-crypto@vger.kernel.org Cc: x86@kernel.org Subject: [PATCH] crypto: x86/aes-xts - simplify loop in xts_crypt_slowpath() Date: Fri, 19 Apr 2024 22:54:55 -0700 Message-ID: <20240420055455.25179-1-ebiggers@kernel.org> X-Mailer: git-send-email 2.44.0 Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Eric Biggers Since the total length processed by the loop in xts_crypt_slowpath() is a multiple of AES_BLOCK_SIZE, just round the length down to AES_BLOCK_SIZE even on the last step. This doesn't change behavior, as the last step will process a multiple of AES_BLOCK_SIZE regardless. Signed-off-by: Eric Biggers --- arch/x86/crypto/aesni-intel_glue.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) base-commit: 543ea178fbfadeaf79e15766ac989f3351349f02 diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c index 110b3282a1f2..02a4c0c276df 100644 --- a/arch/x86/crypto/aesni-intel_glue.c +++ b/arch/x86/crypto/aesni-intel_glue.c @@ -933,20 +933,17 @@ xts_crypt_slowpath(struct skcipher_request *req, xts_crypt_func crypt_func) } err = skcipher_walk_virt(&walk, req, false); while (walk.nbytes) { - unsigned int nbytes = walk.nbytes; - - if (nbytes < walk.total) - nbytes = round_down(nbytes, AES_BLOCK_SIZE); - kernel_fpu_begin(); - (*crypt_func)(&ctx->crypt_ctx, walk.src.virt.addr, - walk.dst.virt.addr, nbytes, req->iv); + (*crypt_func)(&ctx->crypt_ctx, + walk.src.virt.addr, walk.dst.virt.addr, + walk.nbytes & ~(AES_BLOCK_SIZE - 1), req->iv); kernel_fpu_end(); - err = skcipher_walk_done(&walk, walk.nbytes - nbytes); + err = skcipher_walk_done(&walk, + walk.nbytes & (AES_BLOCK_SIZE - 1)); } if (err || !tail) return err;