From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 67C84C433DF for ; Wed, 5 Aug 2020 16:55:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 308F022CBE for ; Wed, 5 Aug 2020 16:55:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=foundries-io.20150623.gappssmtp.com header.i=@foundries-io.20150623.gappssmtp.com header.b="sr0mHcaF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728328AbgHEQzu (ORCPT ); Wed, 5 Aug 2020 12:55:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47326 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728268AbgHEQxw (ORCPT ); Wed, 5 Aug 2020 12:53:52 -0400 Received: from mail-wm1-x341.google.com (mail-wm1-x341.google.com [IPv6:2a00:1450:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B1299C0A3BFE for ; Wed, 5 Aug 2020 06:34:43 -0700 (PDT) Received: by mail-wm1-x341.google.com with SMTP id c80so5851330wme.0 for ; Wed, 05 Aug 2020 06:34:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foundries-io.20150623.gappssmtp.com; s=20150623; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=jUm96D8c3KBJ6s62BHerMk/IRi7rhmWP25W/0OLk1ZU=; b=sr0mHcaFg3/B+cuW/APq4vgco/kRUKHGPN8ruB0hAt74JLypp6gI0mmL4/QMzOgpPZ xX1Chxnnu4QLipjFo6IFNfNjaZjq98LJRBn4EIPSCzF/pqCAXI22oAVUVKy+yAOYe2gC nz8b0qiJ8r5foCm/fMq1gaFXi97wA9uPx90RB5rqCFvDC9X64J9d9pfuSHdfHMXDmotg KJ84Q85TUeoNXYyMq7hWD9y0ujzl8hCBZaOGr8LlOnFFrTL4R126pLFooZuVeJoR0EOO tcJlbJ6IhM7cTQ6bH/2wlMm/iVAzf7XJvlDA7AaU0t3HAxjh2Z8ZEHCN/sc21xmgP7Mk GXIQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=jUm96D8c3KBJ6s62BHerMk/IRi7rhmWP25W/0OLk1ZU=; b=UmxvMwUrSPsG+C4jB8ACjJzAJ8NTHxlY593KlDXEYykXO8UETVWaPbJoPXFv/4LVPo hTWmpJ1EpjHF+ps7H6oyPI0EE87bhq/rPrSke/J8jm/HqkI+bELu4oSBU2JsmvFfSbwW 08IE2Si/iz8lvOrgxYk9xFiIMY6kfNQ045WyNFlNL84KqMkoebFvSZYjK2OJs94Tjwnh ISFbngkuSNe/9mDWYBNkRt53bLD5IrUfiDoEW35G40um10ozhtEuILO3XuBAF4xIPYOZ 21KYa3TG4X6Z3U6jeXT8BEl0lObs9ftBV4qivOdht/kjW0ur7yjWY2Nn8JAI2NPhFVpY p9XA== X-Gm-Message-State: AOAM530XnZKkwqODqC9Z1nBiqXTGRRpVeyeQ2M/4+DiIxICF2UHb0wAa X55G5xTMGsUmoF8qyZhcPgZPcSZCV0ng8Q== X-Google-Smtp-Source: ABdhPJyRcs7JRyS8/812me57oeRdjLSDfD7mFLhAWXcdCLI8E9eJI4aXg9Szz5CIpD7pOchaqXtHgg== X-Received: by 2002:a1c:9803:: with SMTP id a3mr3193427wme.57.1596634462319; Wed, 05 Aug 2020 06:34:22 -0700 (PDT) Received: from trex (239.red-83-34-184.dynamicip.rima-tde.net. [83.34.184.239]) by smtp.gmail.com with ESMTPSA id j2sm2973661wrp.46.2020.08.05.06.34.21 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Wed, 05 Aug 2020 06:34:21 -0700 (PDT) From: "Jorge Ramirez-Ortiz, Foundries" X-Google-Original-From: "Jorge Ramirez-Ortiz, Foundries" Date: Wed, 5 Aug 2020 15:34:20 +0200 To: Jorge Ramirez-Ortiz Cc: sumit.garg@linaro.org, mpm@selenic.com, herbert@gondor.apana.org.au, jens.wiklander@linaro.org, arnd@arndb.de, ricardo@foundries.io, mike@foundries.io, gregkh@linuxfoundation.org, op-tee@lists.trustedfirmware.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCHv2 2/2] hwrng: optee: fix wait use case Message-ID: <20200805133420.GA8276@trex> References: <20200723084622.31134-1-jorge@foundries.io> <20200723084622.31134-2-jorge@foundries.io> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200723084622.31134-2-jorge@foundries.io> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On 23/07/20, Jorge Ramirez-Ortiz wrote: > The current code waits for data to be available before attempting a > second read. However the second read would not be executed as the > while loop exits. > > This fix does not wait if all data has been read and reads a second > time if only partial data was retrieved on the first read. > > This fix also does not attempt to read if not data is requested. > > Signed-off-by: Jorge Ramirez-Ortiz > --- > v2: tidy up the while loop to avoid reading when no data is requested > > drivers/char/hw_random/optee-rng.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/char/hw_random/optee-rng.c b/drivers/char/hw_random/optee-rng.c > index 5bc4700c4dae..a99d82949981 100644 > --- a/drivers/char/hw_random/optee-rng.c > +++ b/drivers/char/hw_random/optee-rng.c > @@ -122,14 +122,14 @@ static int optee_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) > if (max > MAX_ENTROPY_REQ_SZ) > max = MAX_ENTROPY_REQ_SZ; > > - while (read == 0) { > + while (read < max) { > rng_size = get_optee_rng_data(pvt_data, data, (max - read)); > > data += rng_size; > read += rng_size; > > if (wait && pvt_data->data_rate) { > - if (timeout-- == 0) > + if ((timeout-- == 0) || (read == max)) > return read; > msleep((1000 * (max - read)) / pvt_data->data_rate); > } else { any comments please?