kvm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jason Gunthorpe <jgg@nvidia.com>
To: Eric Farman <farman@linux.ibm.com>
Cc: Matthew Rosato <mjrosato@linux.ibm.com>,
	Alex Williamson <alex.williamson@redhat.com>,
	Liu Yi L <yi.l.liu@intel.com>, Halil Pasic <pasic@linux.ibm.com>,
	kvm@vger.kernel.org, linux-s390@vger.kernel.org
Subject: Re: [PATCH v1 08/18] vfio/ccw: Check that private pointer is not NULL
Date: Thu, 2 Jun 2022 16:05:54 -0300	[thread overview]
Message-ID: <20220602190554.GE3936592@nvidia.com> (raw)
In-Reply-To: <20220602171948.2790690-9-farman@linux.ibm.com>

On Thu, Jun 02, 2022 at 07:19:38PM +0200, Eric Farman wrote:
> The subchannel->dev->drvdata pointer is set in vfio_ccw_sch_probe()
> and cleared in vfio_ccw_sch_remove(). In a purely defensive move,
> let's check that the resultant pointer exists before operating on it
> any way, since some lifecycle changes are forthcoming.

There should be no possibility for the drvdata to be NULL in any of
these routines, if that happens there is some kernel race bug with
removal.

Thus all of these should be WARN_ON to document that they cannot happen.

Jason

  parent reply	other threads:[~2022-06-02 19:06 UTC|newest]

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-02 17:19 [PATCH v1 00/18] VFIO ccw/mdev rework Eric Farman
2022-06-02 17:19 ` [PATCH v1 01/18] vfio/ccw: Remove UUID from s390 debug log Eric Farman
2022-06-02 18:55   ` Jason Gunthorpe
2022-06-02 19:51   ` Matthew Rosato
2022-06-03 19:03     ` Eric Farman
2022-06-06 20:45       ` Matthew Rosato
2022-06-02 17:19 ` [PATCH v1 02/18] vfio/ccw: Fix FSM state if mdev probe fails Eric Farman
2022-06-02 18:58   ` Jason Gunthorpe
2022-06-03 13:21   ` Matthew Rosato
2022-06-03 19:12     ` Eric Farman
2022-06-06 20:44       ` Matthew Rosato
2022-06-02 17:19 ` [PATCH v1 03/18] vfio/ccw: Ensure mdev->dev is cleared on mdev remove Eric Farman
2022-06-03 13:25   ` Matthew Rosato
2022-06-03 13:37     ` Jason Gunthorpe
2022-06-03 15:20       ` Tony Krowiak
2022-06-02 17:19 ` [PATCH v1 04/18] vfio/ccw: Do not change FSM state in subchannel event Eric Farman
2022-06-02 17:19 ` [PATCH v1 05/18] vfio/ccw: Remove private->mdev Eric Farman
2022-06-02 19:02   ` Jason Gunthorpe
2022-06-02 19:13     ` Eric Farman
2022-06-02 17:19 ` [PATCH v1 06/18] vfio/ccw: Pass enum to FSM event jumptable Eric Farman
2022-06-02 19:02   ` Jason Gunthorpe
2022-06-02 19:22   ` Matthew Rosato
2022-06-02 17:19 ` [PATCH v1 07/18] vfio/ccw: Flatten MDEV device (un)register Eric Farman
2022-06-02 19:03   ` Jason Gunthorpe
2022-06-02 19:14   ` Matthew Rosato
2022-06-03 20:38     ` Eric Farman
2022-06-02 17:19 ` [PATCH v1 08/18] vfio/ccw: Check that private pointer is not NULL Eric Farman
2022-06-02 19:04   ` Matthew Rosato
2022-06-02 19:05   ` Jason Gunthorpe [this message]
2022-06-02 17:19 ` [PATCH v1 09/18] vfio/ccw: Create an OPEN FSM Event Eric Farman
2022-06-02 19:08   ` Jason Gunthorpe
2022-06-02 17:19 ` [PATCH v1 10/18] vfio/ccw: Create a CLOSE FSM event Eric Farman
2022-06-02 19:10   ` Jason Gunthorpe
2022-06-02 17:19 ` [PATCH v1 11/18] vfio/ccw: Refactor vfio_ccw_mdev_reset Eric Farman
2022-06-02 19:11   ` Jason Gunthorpe
2022-06-02 17:19 ` [PATCH v1 12/18] vfio/ccw: Move FSM open/close to MDEV open/close Eric Farman
2022-06-02 19:14   ` Jason Gunthorpe
2022-06-02 17:19 ` [PATCH v1 13/18] vfio/mdev: Consolidate all the device_api sysfs into the core code Eric Farman
2022-06-03  6:36   ` Christoph Hellwig
2022-06-03 14:55   ` Tony Krowiak
2022-06-06 19:43   ` Kirti Wankhede
2022-06-10  7:22   ` Tian, Kevin
2022-06-02 17:19 ` [PATCH v1 14/18] vfio/mdev: Add mdev available instance checking to the core Eric Farman
2022-06-03 15:02   ` Tony Krowiak
2022-06-06 20:02   ` Kirti Wankhede
2022-06-06 20:23     ` Eric Farman
2022-06-06 20:37       ` Matthew Rosato
2022-06-10  7:43       ` Tian, Kevin
2022-06-13  6:46         ` Christoph Hellwig
2022-06-13 14:08           ` Eric Farman
2022-06-02 17:19 ` [PATCH v1 15/18] vfio/ccw: Manage private with mdev Eric Farman
2022-06-02 17:19 ` [PATCH v1 16/18] vfio/ccw: Create a get_private routine Eric Farman
2022-06-02 19:17   ` Jason Gunthorpe
2022-06-02 17:19 ` [PATCH v1 17/18] vfio: Export vfio_device_try_get() Eric Farman
2022-06-03  7:46   ` Cornelia Huck
2022-06-02 17:19 ` [PATCH v1 18/18] vfio/ccw: Manage ccw/mdev reference counts Eric Farman
2022-06-02 19:20   ` Jason Gunthorpe
2022-06-02 19:29 ` [PATCH v1 00/18] VFIO ccw/mdev rework Jason Gunthorpe
2022-06-10  4:11 ` Yi Liu

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=20220602190554.GE3936592@nvidia.com \
    --to=jgg@nvidia.com \
    --cc=alex.williamson@redhat.com \
    --cc=farman@linux.ibm.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=mjrosato@linux.ibm.com \
    --cc=pasic@linux.ibm.com \
    --cc=yi.l.liu@intel.com \
    /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).