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author | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2008-10-26 11:02:03 (GMT) |
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committer | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2008-10-31 07:48:26 (GMT) |
commit | 8449fc3ae58bf8ee5acbd2280754cde67b5db128 (patch) | |
tree | 01c632f8b1adf31f937a67f1e2d000053eea1f1a /scripts/headers_check.pl | |
parent | 638570b54346f140bc09b986d93e76025d35180f (diff) | |
download | linux-fsl-qoriq-8449fc3ae58bf8ee5acbd2280754cde67b5db128.tar.xz |
ieee1394: dv1394: fix possible deadlock in multithreaded clients
Fix a possible though highly unlikely deadlock:
Thread A: Thread B:
- acquire mmap_sem - dv1394_ioctl/read/write()
- dv1394_mmap() - acquire video->mtx
- acquire video->mtx - copy_to/from_user(), possible page fault:
acquire mmap_sem
The simplest fix is to use mutex_trylock() instead of mutex_lock() in
dv1394_mmap(). This changes the behavior under contention in a way
which is visible to userspace clients. However, my guess is that no
clients exist which use mmap vs. ioctl/read/write on the dv1394
character device file interface in concurrent threads.
Reported-by: Johannes Weiner <hannes@saeurebad.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Diffstat (limited to 'scripts/headers_check.pl')
0 files changed, 0 insertions, 0 deletions