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author | Tejun Heo <tj@kernel.org> | 2012-08-03 10:30:45 -0700 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-13 05:28:03 +0900 |
commit | 21de4eb26ec0b1b9c484da823fbcd1d3a48afec9 (patch) | |
tree | ec3e1821f50f68c7d18a9626c8a5455e943a782a /arch/powerpc | |
parent | fe77d1bb93b50233d9d2932d348c1a78214ea485 (diff) | |
download | kernel_samsung_crespo-21de4eb26ec0b1b9c484da823fbcd1d3a48afec9.zip kernel_samsung_crespo-21de4eb26ec0b1b9c484da823fbcd1d3a48afec9.tar.gz kernel_samsung_crespo-21de4eb26ec0b1b9c484da823fbcd1d3a48afec9.tar.bz2 |
workqueue: add missing smp_wmb() in process_one_work()
commit 959d1af8cffc8fd38ed53e8be1cf4ab8782f9c00 upstream.
WORK_STRUCT_PENDING is used to claim ownership of a work item and
process_one_work() releases it before starting execution. When
someone else grabs PENDING, all pre-release updates to the work item
should be visible and all updates made by the new owner should happen
afterwards.
Grabbing PENDING uses test_and_set_bit() and thus has a full barrier;
however, clearing doesn't have a matching wmb. Given the preceding
spin_unlock and use of clear_bit, I don't believe this can be a
problem on an actual machine and there hasn't been any related report
but it still is theretically possible for clear_pending to permeate
upwards and happen before work->entry update.
Add an explicit smp_wmb() before work_clear_pending().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/powerpc')
0 files changed, 0 insertions, 0 deletions