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| author | KAMEZAWA Hiroyuki <[email protected]> | 2012-10-19 08:00:55 +0000 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2012-10-19 21:32:10 +0000 |
| commit | 9e7814404b77c3e8920bee4277162bf3a7460505 (patch) | |
| tree | f7542b049f29150680507dd211925401beadac9a /lib/dma-debug.c | |
| parent | Merge branch 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/ti... (diff) | |
| download | kernel-9e7814404b77c3e8920bee4277162bf3a7460505.tar.gz kernel-9e7814404b77c3e8920bee4277162bf3a7460505.zip | |
hold task->mempolicy while numa_maps scans.
/proc/<pid>/numa_maps scans vma and show mempolicy under
mmap_sem. It sometimes accesses task->mempolicy which can
be freed without mmap_sem and numa_maps can show some
garbage while scanning.
This patch tries to take reference count of task->mempolicy at reading
numa_maps before calling get_vma_policy(). By this, task->mempolicy
will not be freed until numa_maps reaches its end.
V2->v3
- updated comments to be more verbose.
- removed task_lock() in numa_maps code.
V1->V2
- access task->mempolicy only once and remember it. Becase kernel/exit.c
can overwrite it.
Signed-off-by: KAMEZAWA Hiroyuki <[email protected]>
Acked-by: David Rientjes <[email protected]>
Acked-by: KOSAKI Motohiro <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Diffstat (limited to 'lib/dma-debug.c')
0 files changed, 0 insertions, 0 deletions