Re: [PATCH v2 1/3] crypto: sahara - avoid needlessly saving and restoring sahara_ctx

From: Fabio Estevam <festevam@gmail.com>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "Marek Vašut" <marex@denx.de>,
	"Steffen Trumtrar" <s.trumtrar@pengutronix.de>,
	"Tom Lendacky" <thomas.lendacky@amd.com>,
	"Russell King" <linux@arm.linux.org.uk>,
	linux-crypto@vger.kernel.org,
	"Fabio Estevam" <fabio.estevam@nxp.com>
Subject: Re: [PATCH v2 1/3] crypto: sahara - avoid needlessly saving and restoring sahara_ctx
Date: Tue, 2 Feb 2016 11:41:56 -0200	[thread overview]
Message-ID: <CAOMZO5BE49yzqpEy3TAGAyY52XR_sq6NtFa6e1fdkDAP9Xt4Ow@mail.gmail.com> (raw)
In-Reply-To: <20160125140728.GA8414@gondor.apana.org.au>

Hi Herbert,

On Mon, Jan 25, 2016 at 12:07 PM, Herbert Xu
<herbert@gondor.apana.org.au> wrote:

> Very good.  Not only is it a waste, it's a gaping security hole
> because modifying the tfm from import will corrupt it.
>
> But this is not enough, you're still copying things like the mutex
> which should not be copied but instead should be reinitialised in
> import.

So import() will look like this?

static int sahara_sha_import(struct ahash_request *req, const void *in)
{
    struct sahara_sha_reqctx *rctx = ahash_request_ctx(req);

    mutex_init(&rctx->mutex);
    memcpy(rctx, in, sizeof(struct sahara_sha_reqctx));

    return 0;
}

Thanks