linux-amlogic.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Ard Biesheuvel <ardb@kernel.org>
To: linux-crypto@vger.kernel.org
Cc: "Eric Biggers" <ebiggers@google.com>,
	"Corentin Labbe" <clabbe.montjoie@gmail.com>,
	"Ayush Sawal" <ayush.sawal@chelsio.com>,
	"Jamie Iles" <jamie@jamieiles.com>,
	"Fabio Estevam" <festevam@gmail.com>,
	"Ard Biesheuvel" <ardb@kernel.org>,
	"Herbert Xu" <herbert@gondor.apana.org.au>,
	"Horia Geantă" <horia.geanta@nxp.com>,
	"Rohit Maheshwari" <rohitm@chelsio.com>,
	"Chen-Yu Tsai" <wens@csie.org>,
	"Corentin Labbe" <clabbe@baylibre.com>,
	"NXP Linux Team" <linux-imx@nxp.com>,
	"Tom Lendacky" <thomas.lendacky@amd.com>,
	"Sascha Hauer" <s.hauer@pengutronix.de>,
	"Vinay Kumar Yadav" <vinay.yadav@chelsio.com>,
	"Maxime Ripard" <mripard@kernel.org>,
	"Matthias Brugger" <matthias.bgg@gmail.com>,
	linux-amlogic@lists.infradead.org, linux-omap@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	"John Allen" <john.allen@amd.com>,
	"Tero Kristo" <t-kristo@ti.com>,
	"Pengutronix Kernel Team" <kernel@pengutronix.de>,
	"Shawn Guo" <shawnguo@kernel.org>,
	"David S. Miller" <davem@davemloft.net>
Subject: [PATCH v4 09/13] crypto: mxs-dcp - permit asynchronous skcipher as fallback
Date: Tue,  7 Jul 2020 09:31:59 +0300	[thread overview]
Message-ID: <20200707063203.5018-10-ardb@kernel.org> (raw)
In-Reply-To: <20200707063203.5018-1-ardb@kernel.org>

Even though the mxs-dcp driver implements asynchronous versions of
ecb(aes) and cbc(aes), the fallbacks it allocates are required to be
synchronous. Given that SIMD based software implementations are usually
asynchronous as well, even though they rarely complete asynchronously
(this typically only happens in cases where the request was made from
softirq context, while SIMD was already in use in the task context that
it interrupted), these implementations are disregarded, and either the
generic C version or another table based version implemented in assembler
is selected instead.

Since falling back to synchronous AES is not only a performance issue, but
potentially a security issue as well (due to the fact that table based AES
is not time invariant), let's fix this, by allocating an ordinary skcipher
as the fallback, and invoke it with the completion routine that was given
to the outer request.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
---
 drivers/crypto/mxs-dcp.c | 33 ++++++++++----------
 1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/drivers/crypto/mxs-dcp.c b/drivers/crypto/mxs-dcp.c
index d84530293036..909a7eb748e3 100644
--- a/drivers/crypto/mxs-dcp.c
+++ b/drivers/crypto/mxs-dcp.c
@@ -97,7 +97,7 @@ struct dcp_async_ctx {
 	unsigned int			hot:1;
 
 	/* Crypto-specific context */
-	struct crypto_sync_skcipher	*fallback;
+	struct crypto_skcipher		*fallback;
 	unsigned int			key_len;
 	uint8_t				key[AES_KEYSIZE_128];
 };
@@ -105,6 +105,7 @@ struct dcp_async_ctx {
 struct dcp_aes_req_ctx {
 	unsigned int	enc:1;
 	unsigned int	ecb:1;
+	struct skcipher_request fallback_req;	// keep at the end
 };
 
 struct dcp_sha_req_ctx {
@@ -426,21 +427,20 @@ static int dcp_chan_thread_aes(void *data)
 static int mxs_dcp_block_fallback(struct skcipher_request *req, int enc)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+	struct dcp_aes_req_ctx *rctx = skcipher_request_ctx(req);
 	struct dcp_async_ctx *ctx = crypto_skcipher_ctx(tfm);
-	SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, ctx->fallback);
 	int ret;
 
-	skcipher_request_set_sync_tfm(subreq, ctx->fallback);
-	skcipher_request_set_callback(subreq, req->base.flags, NULL, NULL);
-	skcipher_request_set_crypt(subreq, req->src, req->dst,
+	skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback);
+	skcipher_request_set_callback(&rctx->fallback_req, req->base.flags,
+				      req->base.complete, req->base.data);
+	skcipher_request_set_crypt(&rctx->fallback_req, req->src, req->dst,
 				   req->cryptlen, req->iv);
 
 	if (enc)
-		ret = crypto_skcipher_encrypt(subreq);
+		ret = crypto_skcipher_encrypt(&rctx->fallback_req);
 	else
-		ret = crypto_skcipher_decrypt(subreq);
-
-	skcipher_request_zero(subreq);
+		ret = crypto_skcipher_decrypt(&rctx->fallback_req);
 
 	return ret;
 }
@@ -510,24 +510,25 @@ static int mxs_dcp_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
 	 * but is supported by in-kernel software implementation, we use
 	 * software fallback.
 	 */
-	crypto_sync_skcipher_clear_flags(actx->fallback, CRYPTO_TFM_REQ_MASK);
-	crypto_sync_skcipher_set_flags(actx->fallback,
+	crypto_skcipher_clear_flags(actx->fallback, CRYPTO_TFM_REQ_MASK);
+	crypto_skcipher_set_flags(actx->fallback,
 				  tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);
-	return crypto_sync_skcipher_setkey(actx->fallback, key, len);
+	return crypto_skcipher_setkey(actx->fallback, key, len);
 }
 
 static int mxs_dcp_aes_fallback_init_tfm(struct crypto_skcipher *tfm)
 {
 	const char *name = crypto_tfm_alg_name(crypto_skcipher_tfm(tfm));
 	struct dcp_async_ctx *actx = crypto_skcipher_ctx(tfm);
-	struct crypto_sync_skcipher *blk;
+	struct crypto_skcipher *blk;
 
-	blk = crypto_alloc_sync_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK);
+	blk = crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK);
 	if (IS_ERR(blk))
 		return PTR_ERR(blk);
 
 	actx->fallback = blk;
-	crypto_skcipher_set_reqsize(tfm, sizeof(struct dcp_aes_req_ctx));
+	crypto_skcipher_set_reqsize(tfm, sizeof(struct dcp_aes_req_ctx) +
+					 crypto_skcipher_reqsize(blk));
 	return 0;
 }
 
@@ -535,7 +536,7 @@ static void mxs_dcp_aes_fallback_exit_tfm(struct crypto_skcipher *tfm)
 {
 	struct dcp_async_ctx *actx = crypto_skcipher_ctx(tfm);
 
-	crypto_free_sync_skcipher(actx->fallback);
+	crypto_free_skcipher(actx->fallback);
 }
 
 /*
-- 
2.17.1


_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic

  parent reply	other threads:[~2020-07-07  6:34 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-07  6:31 [PATCH v4 00/13] crypto: permit asynchronous skciphers as driver fallbacks Ard Biesheuvel
2020-07-07  6:31 ` [PATCH v4 01/13] crypto: amlogic-gxl - default to build as module Ard Biesheuvel
2020-07-07  6:31 ` [PATCH v4 02/13] crypto: amlogic-gxl - permit async skcipher as fallback Ard Biesheuvel
2020-07-07  6:31 ` [PATCH v4 03/13] crypto: omap-aes - permit asynchronous " Ard Biesheuvel
2020-07-07  6:31 ` [PATCH v4 04/13] crypto: sun4i " Ard Biesheuvel
2020-07-07  6:31 ` [PATCH v4 05/13] crypto: sun8i-ce " Ard Biesheuvel
2020-07-08  7:53   ` Corentin Labbe
2020-07-07  6:31 ` [PATCH v4 06/13] crypto: sun8i-ss " Ard Biesheuvel
2020-07-07  6:31 ` [PATCH v4 07/13] crypto: ccp " Ard Biesheuvel
2020-07-07 20:04   ` John Allen
2020-07-07  6:31 ` [PATCH v4 08/13] crypto: chelsio " Ard Biesheuvel
2020-07-07  6:31 ` Ard Biesheuvel [this message]
2020-07-07  6:32 ` [PATCH v4 10/13] crypto: picoxcell " Ard Biesheuvel
2020-07-07  6:32 ` [PATCH v4 11/13] crypto: qce " Ard Biesheuvel
2020-07-07  6:32 ` [PATCH v4 12/13] crypto: sahara " Ard Biesheuvel
2020-07-07  6:32 ` [PATCH v4 13/13] crypto: mediatek - use AES library for GCM key derivation Ard Biesheuvel
2020-07-16 11:53 ` [PATCH v4 00/13] crypto: permit asynchronous skciphers as driver fallbacks Herbert Xu
2020-08-17 17:48 ` patchwork-bot+linux-amlogic

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200707063203.5018-10-ardb@kernel.org \
    --to=ardb@kernel.org \
    --cc=ayush.sawal@chelsio.com \
    --cc=clabbe.montjoie@gmail.com \
    --cc=clabbe@baylibre.com \
    --cc=davem@davemloft.net \
    --cc=ebiggers@google.com \
    --cc=festevam@gmail.com \
    --cc=herbert@gondor.apana.org.au \
    --cc=horia.geanta@nxp.com \
    --cc=jamie@jamieiles.com \
    --cc=john.allen@amd.com \
    --cc=kernel@pengutronix.de \
    --cc=linux-amlogic@lists.infradead.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-crypto@vger.kernel.org \
    --cc=linux-imx@nxp.com \
    --cc=linux-omap@vger.kernel.org \
    --cc=matthias.bgg@gmail.com \
    --cc=mripard@kernel.org \
    --cc=rohitm@chelsio.com \
    --cc=s.hauer@pengutronix.de \
    --cc=shawnguo@kernel.org \
    --cc=t-kristo@ti.com \
    --cc=thomas.lendacky@amd.com \
    --cc=vinay.yadav@chelsio.com \
    --cc=wens@csie.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).