Commit 16d0f85e authored May 06, 2019 by Baolin Wang Committed by Vinod Koul May 21, 2019

dmaengine: sprd: Fix the possible crash when getting descriptor status



We will get a NULL virtual descriptor by vchan_find_desc() when the descriptor
has been submitted, that will crash the kernel when getting the descriptor
status.

In this case, since the descriptor has been submitted to process, but it
is not completed now, which means the descriptor is listed into the
'vc->desc_submitted' list now. So we can not get current processing descriptor
by vchan_find_desc(), but the pointer 'schan->cur_desc' will point to the
current processing descriptor, then we can use 'schan->cur_desc' to get
current processing descriptor's status to avoid this issue.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

parent 49225249

drivers/dma/sprd-dma.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -625,7 +625,7 @@ static enum dma_status sprd_dma_tx_status(struct dma_chan *chan,
		else
		pos = 0;
		} else if (schan->cur_desc && schan->cur_desc->vd.tx.cookie == cookie) {
		struct sprd_dma_desc *sdesc = to_sprd_dma_desc(vd);
		struct sprd_dma_desc *sdesc = schan->cur_desc;

		if (sdesc->dir == DMA_DEV_TO_MEM)
		pos = sprd_dma_get_dst_addr(schan);

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