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author | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2008-08-16 00:11:48 +0200 |
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committer | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2008-10-15 22:21:08 +0200 |
commit | 10963ea1bd966ba46a46178c4d6abcdf3c23538d (patch) | |
tree | d11eb5adbca18c9570c28fff4dffe0f7d4d1da1c /Documentation/laptops | |
parent | ed6ffd08084c68e9c3911e27706dec9d4c9a4175 (diff) |
ieee1394: raw1394: replace BKL by local mutex, make ioctl() and mmap() thread-safe
This removes the last usage of the Big Kernel Lock from the ieee1394
stack, i.e. from raw1394's (unlocked_)ioctl and compat_ioctl.
The ioctl()s don't need to take the BKL, but they need to be serialized
per struct file *. In particular, accesses to ->iso_state need to be
serial. We simply use a blocking mutex for this purpose because
libraw1394 does not use O_NONBLOCK. In practice, there is no lock
contention anyway because most if not all libraw1394 clients use a
libraw1394 handle only in a single thread.
mmap() also accesses ->iso_state. Until now this was unprotected
against concurrent changes by ioctls. Fix this bug while we are at it.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Diffstat (limited to 'Documentation/laptops')
0 files changed, 0 insertions, 0 deletions