dri-devel.lists.freedesktop.org archive mirror
 help / color / mirror / Atom feed
From: Thierry Reding <thierry.reding@gmail.com>
To: Paulo Zanoni <przanoni@gmail.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	DRI Development <dri-devel@lists.freedesktop.org>
Subject: Re: [PATCH] drm/sysfs: Do not drop device reference twice
Date: Wed, 30 Oct 2013 22:18:15 +0100	[thread overview]
Message-ID: <20131030211814.GC7686@mithrandir> (raw)
In-Reply-To: <CA+gsUGSjJmqu9Ph0znE5XJJOJdeh-UT3z2Cjm7sEMB4F+ZtAvg@mail.gmail.com>


[-- Attachment #1.1: Type: text/plain, Size: 1003 bytes --]

On Wed, Oct 30, 2013 at 02:05:02PM -0200, Paulo Zanoni wrote:
> 2013/10/30 Thierry Reding <thierry.reding@gmail.com>:
> > device_unregister() already drops its reference to the struct device, so
> > explicitly calling put_device() before device_unregister() can cause the
> > device to have been freed before it can be unregistered.
> >
> > Signed-off-by: Thierry Reding <treding@nvidia.com>
> 
> I started investigating this problem yesterday and reached the same
> conclusion. The connector path can be easily reproduced on i915.ko:
> get a machine that has an eDP panel, physically disconnect the panel,
> boot the machine, "modprobe i915" and watch the segfault.
> 
> Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
> Tested-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
> 
> I didn't really bisect, but I believe this is probably a regression
> from "drm/sysfs: sort out minor and connector device object
> lifetimes".

Yes, I think that's the one that broke it.

Thierry

[-- Attachment #1.2: Type: application/pgp-signature, Size: 836 bytes --]

[-- Attachment #2: Type: text/plain, Size: 159 bytes --]

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel

  reply	other threads:[~2013-10-30 21:18 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-30 10:59 [PATCH] drm/sysfs: Do not drop device reference twice Thierry Reding
2013-10-30 16:05 ` Paulo Zanoni
2013-10-30 21:18   ` Thierry Reding [this message]
2013-10-30 18:06 ` Ben Widawsky

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=20131030211814.GC7686@mithrandir \
    --to=thierry.reding@gmail.com \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=przanoni@gmail.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).