From: Pete Eberlein <pete@sensoray.com>
To: linux-media <linux-media@vger.kernel.org>
Cc: viro@ZenIV.linux.org.uk, mchehab@redhat.com
Subject: videobuf mmap deadlock
Date: Fri, 01 Nov 2013 11:54:42 -0700 [thread overview]
Message-ID: <5273F8F2.5070901@sensoray.com> (raw)
The patch "videobuf_vm_{open,close} race fixes"
https://linuxtv.org/patch/18365/ introduced a deadlock in 3.11.
My driver uses videobuf_vmalloc initialized with ext_lock set to NULL.
My driver's mmap function calls videobuf_mmap_mapper
videobuf_mmap_mapper calls videobuf_queue_lock on q
videobuf_mmap_mapper calls __videobuf_mmap_mapper
__videobuf_mmap_mapper calls videobuf_vm_open
videobuf_vm_open calls videobuf_queue_lock on q (introduced by above patch)
deadlocked
This is not an issue if ext_lock is non-NULL, since videobuf_queue_lock
is a no-op in that case.
Did I do something wrong, or is this a valid regression?
Regards,
Pete Eberlein
next reply other threads:[~2013-11-01 19:42 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-01 18:54 Pete Eberlein [this message]
2013-11-11 12:29 ` videobuf mmap deadlock Hans Verkuil
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=5273F8F2.5070901@sensoray.com \
--to=pete@sensoray.com \
--cc=linux-media@vger.kernel.org \
--cc=mchehab@redhat.com \
--cc=viro@ZenIV.linux.org.uk \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.