From: Al Viro <viro@ZenIV.linux.org.uk>
To: YoungJun Cho <yj44.cho@samsung.com>
Cc: dri-devel@lists.freedesktop.org
Subject: [RFC] deadlock in "drm/exynos: fix wrong pointer access at vm close"
Date: Sun, 22 Sep 2013 22:29:11 +0100 [thread overview]
Message-ID: <20130922212911.GU13318@ZenIV.linux.org.uk> (raw)
You have drm_dev->struct_mutex grabbed before ->mmap_sem in
exynos_drm_gem_mmap_ioctl() and after - in exynos_drm_gem_fault()
(since ->fault() is always called with ->mmap_sem held). Looks like
a garden-variety AB-BA deadlock...
Incidentally, what should happen if another process shares the
same opened file (e.g. inherited over fork()) and does mmap() just
as we have ->f_op switched?
next reply other threads:[~2013-09-22 22:30 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-22 21:29 Al Viro [this message]
2013-09-23 7:49 ` [RFC] deadlock in "drm/exynos: fix wrong pointer access at vm close" Inki Dae
2013-09-23 13:07 ` Al Viro
2013-09-24 4:41 ` Inki Dae
2013-09-26 3:26 ` Al Viro
2013-09-28 17:17 ` Inki Dae
2013-09-25 4:34 ` Inki Dae
2013-09-26 3:28 ` Al Viro
2013-09-28 17:47 ` Inki Dae
2013-09-28 17:50 ` Inki Dae
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