linux-kernel - Re: [PATCH] nvme: change nvme_passthru

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]

Message-ID: <CANSCoS-RzcutTWHN1t1iyW3GjqNcY5xFUZtJhAThDp5SPPrDAA@mail.gmail.com>
Date:   Thu, 31 Oct 2019 06:59:10 -0700
From:   Charles Machalow <csm10495@...il.com>
To:     Christoph Hellwig <hch@....de>
Cc:     linux-nvme@...ts.infradead.org, marta.rybczynska@...ray.eu,
        Keith Busch <kbusch@...nel.org>, Jens Axboe <axboe@...com>,
        Sagi Grimberg <sagi@...mberg.me>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] nvme: change nvme_passthru_cmd64's result field.

On Thu, Oct 31, 2019, 6:39 AM Christoph Hellwig <hch@....de> wrote

> All that casting is a pretty bad idea.  please just add an explicit
> reserved field before the result, and check that it always is zero
> in the ioctl handler.

Not quite sure what you mean by check for zero in the ioctl handler. I
like the idea of being able to use the same struct for either the
original or 64 ioctls from userspace. I don't believe adding the
explicit rsvd field allows that

- Charlie Scott Machalow

On Thu, Oct 31, 2019 at 6:39 AM Christoph Hellwig <hch@....de> wrote:
>
> On Wed, Oct 30, 2019 at 10:03:38PM -0700, Charles Machalow wrote:
> > Changing nvme_passthru_cmd64's result field to be backwards compatible
> > with the nvme_passthru_cmd/nvme_admin_cmd struct in terms of the result
> > field. With this change the first 32 bits of result in either case
> > point to CQE DW0. This allows userspace tools to use the new structure
> > when using the old ADMIN/IO_CMD ioctls or new ADMIN/IO_CMD64 ioctls.
>
> All that casting is a pretty bad idea.  please just add an explicit
> reserved field before the result, and check that it always is zero
> in the ioctl handler.