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| author | Dan Williams <dan.j.williams@intel.com> | 2010-03-04 05:21:10 +0100 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2010-03-04 05:21:10 +0100 |
| commit | aa75db0080603bae27961c0502812dfd0f522bb3 (patch) | |
| tree | 3e7fbb0ef4415c9f36107a81378f00bba6db9440 /drivers/dma/ioat/dma_v2.c | |
| parent | ioat2: kill pending flag (diff) | |
| download | linux-aa75db0080603bae27961c0502812dfd0f522bb3.tar.xz linux-aa75db0080603bae27961c0502812dfd0f522bb3.zip | |
ioat: close potential BUG_ON race in the descriptor cleanup path
Since ioat_cleanup_preamble() and the update of the last completed
descriptor are not synchronized there is a chance that two cleanup threads
can see descriptors to clean. If the first cleans up all pending
descriptors then the second will trigger the BUG_ON.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/dma/ioat/dma_v2.c')
| -rw-r--r-- | drivers/dma/ioat/dma_v2.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/dma/ioat/dma_v2.c b/drivers/dma/ioat/dma_v2.c index c6e4531fe524..01ed1cfd3eb6 100644 --- a/drivers/dma/ioat/dma_v2.c +++ b/drivers/dma/ioat/dma_v2.c @@ -158,7 +158,7 @@ static void __cleanup(struct ioat2_dma_chan *ioat, unsigned long phys_complete) seen_current = true; } ioat->tail += i; - BUG_ON(!seen_current); /* no active descs have written a completion? */ + BUG_ON(active && !seen_current); /* no active descs have written a completion? */ chan->last_completion = phys_complete; if (ioat->head == ioat->tail) { |