From: Dan Williams <dan.j.williams@intel.com>
To: Dave Jiang <dave.jiang@intel.com>
Cc: Vinod Koul <vkoul@kernel.org>, Jason Gunthorpe <jgg@nvidia.com>,
dmaengine@vger.kernel.org
Subject: Re: [PATCH v7 8/8] dmaengine: idxd: fix cdev setup and free device lifetime issues
Date: Mon, 22 Mar 2021 16:38:48 -0700 [thread overview]
Message-ID: <CAPcyv4j8h3Ec-NX+tfaK+evzG8NQq-meVX8VwELQpDyTsTgZHg@mail.gmail.com> (raw)
In-Reply-To: <161645592123.2002542.5490784749723732920.stgit@djiang5-desk3.ch.intel.com>
On Mon, Mar 22, 2021 at 4:32 PM Dave Jiang <dave.jiang@intel.com> wrote:
>
> The char device setup and cleanup has device lifetime issues regarding when
> parts are initialized and cleaned up. The initialization of struct device is
> done incorrectly. device_initialize() needs to be called on the 'struct
> device' and then additional changes can be added. The ->release() function
> needs to be setup via device_type before dev_set_name() to allow proper
> cleanup. The change re-parents the cdev under the wq->conf_dev to get
> natural reference inheritance. No known dependency on the old device path exists.
>
> Reported-by: Jason Gunthorpe <jgg@nvidia.com>
> Fixes: 42d279f9137a ("dmaengine: idxd: add char driver to expose submission portal to userland")
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> Reviewed-by: Dan Williams <dan.j.williams@intel.com>
[..]
> diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
> index 03079ff54889..8a08988ea9d1 100644
> --- a/drivers/dma/idxd/sysfs.c
> +++ b/drivers/dma/idxd/sysfs.c
> @@ -1174,8 +1174,14 @@ static ssize_t wq_cdev_minor_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> struct idxd_wq *wq = container_of(dev, struct idxd_wq, conf_dev);
> + int minor = -1;
>
> - return sprintf(buf, "%d\n", wq->idxd_cdev.minor);
> + mutex_lock(&wq->wq_lock);
> + if (wq->idxd_cdev)
> + minor = wq->idxd_cdev->minor;
> + mutex_unlock(&wq->wq_lock);
> +
> + return sprintf(buf, "%d\n", minor);
As I mentioned, let's not emit a negative value here. ...not that
userspace should be using this awkward recreation of the existing core
'dev' attribute anyway.
if (minor == -1)
return -ENXIO;
return sprintf(buf, "%d\n", minor);
next prev parent reply other threads:[~2021-03-22 23:39 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-22 23:31 [PATCH v7 0/8] idxd 'struct device' lifetime handling fixes Dave Jiang
2021-03-22 23:31 ` [PATCH v7 1/8] dmaengine: idxd: fix dma device lifetime Dave Jiang
2021-03-22 23:31 ` [PATCH v7 2/8] dmaengine: idxd: cleanup pci interrupt vector allocation management Dave Jiang
2021-03-22 23:31 ` [PATCH v7 3/8] dmaengine: idxd: removal of pcim managed mmio mapping Dave Jiang
2021-03-22 23:31 ` [PATCH v7 4/8] dmaengine: idxd: fix idxd conf_dev 'struct device' lifetime Dave Jiang
2021-03-22 23:31 ` [PATCH v7 5/8] dmaengine: idxd: fix wq " Dave Jiang
2021-03-22 23:31 ` [PATCH v7 6/8] dmaengine: idxd: fix engine conf_dev lifetime Dave Jiang
2021-03-22 23:31 ` [PATCH v7 7/8] dmaengine: idxd: fix group " Dave Jiang
2021-03-22 23:32 ` [PATCH v7 8/8] dmaengine: idxd: fix cdev setup and free device lifetime issues Dave Jiang
2021-03-22 23:38 ` Dan Williams [this message]
2021-03-22 23:44 ` Dave Jiang
2021-03-23 0:02 ` Jason Gunthorpe
2021-03-23 14:48 ` Dave Jiang
2021-03-23 11:45 ` [PATCH v7 0/8] idxd 'struct device' lifetime handling fixes Vinod Koul
2021-03-23 11:56 ` Jason Gunthorpe
2021-03-23 15:44 ` Dave Jiang
2021-03-24 13:56 ` Jason Gunthorpe
2021-03-24 14:57 ` Dave Jiang
2021-03-24 15:03 ` Jason Gunthorpe
2021-03-25 6:28 ` Vinod Koul
2021-03-25 15:25 ` Dave Jiang
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=CAPcyv4j8h3Ec-NX+tfaK+evzG8NQq-meVX8VwELQpDyTsTgZHg@mail.gmail.com \
--to=dan.j.williams@intel.com \
--cc=dave.jiang@intel.com \
--cc=dmaengine@vger.kernel.org \
--cc=jgg@nvidia.com \
--cc=vkoul@kernel.org \
/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).