linux-kernel - Re: [PATCH 3/6] async_tx: Handle DMA devices having support for fewer PQ coefficients

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 1 Feb 2017 22:01:13 -0800
From:   Dan Williams <dan.j.williams@...el.com>
To:     Anup Patel <anup.patel@...adcom.com>
Cc:     Vinod Koul <vinod.koul@...el.com>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        "David S . Miller" <davem@...emloft.net>,
        Jassi Brar <jassisinghbrar@...il.com>,
        Ray Jui <rjui@...adcom.com>,
        Scott Branden <sbranden@...adcom.com>,
        Jon Mason <jonmason@...adcom.com>,
        Rob Rice <rob.rice@...adcom.com>,
        bcm-kernel-feedback-list@...adcom.com,
        "dmaengine@...r.kernel.org" <dmaengine@...r.kernel.org>,
        devicetree@...r.kernel.org,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        linux-crypto@...r.kernel.org,
        linux-raid <linux-raid@...r.kernel.org>
Subject: Re: [PATCH 3/6] async_tx: Handle DMA devices having support for fewer
 PQ coefficients

On Wed, Feb 1, 2017 at 8:47 PM, Anup Patel <anup.patel@...adcom.com> wrote:
> The DMAENGINE framework assumes that if PQ offload is supported by a
> DMA device then all 256 PQ coefficients are supported. This assumption
> does not hold anymore because we now have BCM-SBA-RAID offload engine
> which supports PQ offload with limited number of PQ coefficients.
>
> This patch extends async_tx APIs to handle DMA devices with support
> for fewer PQ coefficients.
>
> Signed-off-by: Anup Patel <anup.patel@...adcom.com>
> Reviewed-by: Scott Branden <scott.branden@...adcom.com>
> ---
>  crypto/async_tx/async_pq.c          |  3 +++
>  crypto/async_tx/async_raid6_recov.c | 12 ++++++++++--
>  include/linux/dmaengine.h           | 19 +++++++++++++++++++
>  include/linux/raid/pq.h             |  3 +++
>  4 files changed, 35 insertions(+), 2 deletions(-)

So, I hate the way async_tx does these checks on each operation, and
it's ok for me to say that because it's my fault. Really it's md that
should be validating engine offload capabilities once at the beginning
of time. I'd rather we move in that direction than continue to pile
onto a bad design.