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| author | Tejun Heo <tj@kernel.org> | 2009-08-14 08:00:49 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2009-08-14 08:00:49 +0200 |
| commit | 971f3918a5a8febbbab355079972fb31ee7c0f33 (patch) | |
| tree | dc7909e934473d6b63460c5aa8d0a37ba62a4f79 /mm/percpu.c | |
| parent | Merge branch 'percpu-for-linus' into percpu-for-next (diff) | |
| download | linux-971f3918a5a8febbbab355079972fb31ee7c0f33.tar.xz linux-971f3918a5a8febbbab355079972fb31ee7c0f33.zip | |
percpu: fix pcpu_reclaim() locking
pcpu_reclaim() calls pcpu_depopulate_chunk() which makes use of pages
array and bitmap returned by pcpu_get_pages_and_bitmap() and thus
should be called under pcpu_alloc_mutex. pcpu_reclaim() released the
mutex before calling depopulate leading to double free and other
strange problems caused by the unexpected concurrent usages of pages
array and bitmap. Fix it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Diffstat (limited to 'mm/percpu.c')
| -rw-r--r-- | mm/percpu.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/percpu.c b/mm/percpu.c index 3f9f182f9b44..42ab0024a6ed 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -1181,12 +1181,13 @@ static void pcpu_reclaim(struct work_struct *work) } spin_unlock_irq(&pcpu_lock); - mutex_unlock(&pcpu_alloc_mutex); list_for_each_entry_safe(chunk, next, &todo, list) { pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size); free_pcpu_chunk(chunk); } + + mutex_unlock(&pcpu_alloc_mutex); } /** |