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| author | Dan Williams <dan.j.williams@intel.com> | 2010-03-03 21:21:10 -0700 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2010-03-03 21:21:10 -0700 |
| commit | aa75db0080603bae27961c0502812dfd0f522bb3 (patch) | |
| tree | 3e7fbb0ef4415c9f36107a81378f00bba6db9440 | |
| parent | 281befa5592b0c5f9a3856b5666c62ac66d3d9ee (diff) | |
| download | linux-3.10-aa75db0080603bae27961c0502812dfd0f522bb3.tar.gz linux-3.10-aa75db0080603bae27961c0502812dfd0f522bb3.tar.bz2 linux-3.10-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>
| -rw-r--r-- | drivers/dma/ioat/dma_v2.c | 2 | ||||
| -rw-r--r-- | drivers/dma/ioat/dma_v3.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/drivers/dma/ioat/dma_v2.c b/drivers/dma/ioat/dma_v2.c index c6e4531fe52..01ed1cfd3eb 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) { diff --git a/drivers/dma/ioat/dma_v3.c b/drivers/dma/ioat/dma_v3.c index bff48e8cffc..39520f2f7da 100644 --- a/drivers/dma/ioat/dma_v3.c +++ b/drivers/dma/ioat/dma_v3.c @@ -293,7 +293,7 @@ static void __cleanup(struct ioat2_dma_chan *ioat, unsigned long phys_complete) } } 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) { dev_dbg(to_dev(chan), "%s: cancel completion timeout\n", |