From: Xuelin Shi <xuelin.shi@xxxxxxxxxxxxx>
This patch does NOT apply to the 3.12 stable tree. If you still want
it applied, please provide a backport.
===============
commit c1f43dd9c20d85e66c4d77e284f64ac114abe3f8 upstream.
The count which is used to get_unmap_data maybe not the same as the
count computed in dmaengine_unmap which causes to free data in a
wrong pool.
This patch fixes this issue by keeping the map count with unmap_data
structure and use this count to get the pool.
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Xuelin Shi <xuelin.shi@xxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/dma/dmaengine.c | 2 ++
include/linux/dmaengine.h | 1 +
2 files changed, 3 insertions(+)
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index a886713937fd..d5d30ed863ce 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -1009,6 +1009,7 @@ static void dmaengine_unmap(struct kref *kref)
dma_unmap_page(dev, unmap->addr[i], unmap->len,
DMA_BIDIRECTIONAL);
}
+ cnt = unmap->map_cnt;
mempool_free(unmap, __get_unmap_pool(cnt)->pool);
}
@@ -1074,6 +1075,7 @@ dmaengine_get_unmap_data(struct device *dev, int nr, gfp_t flags)
memset(unmap, 0, sizeof(*unmap));
kref_init(&unmap->kref);
unmap->dev = dev;
+ unmap->map_cnt = nr;
return unmap;
}
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 8300fb87b84a..72cb0ddb9678 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -429,6 +429,7 @@ typedef bool (*dma_filter_fn)(struct dma_chan *chan, void *filter_param);
typedef void (*dma_async_tx_callback)(void *dma_async_param);
struct dmaengine_unmap_data {
+ u8 map_cnt;
u8 to_cnt;
u8 from_cnt;
u8 bidi_cnt;
--
1.9.3
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