From: Zi Yan <zi.yan@cs.rutgers.edu>
Date: Mon, 8 Jan 2018 15:50:50 +0000 (-0500)
Subject: dmaengine: avoid map_cnt overflow with CONFIG_DMA_ENGINE_RAID
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=0c0eb4caf03bb6d3d92c70560e0530c8fdf62284;p=openwrt%2Fstaging%2Fblogic.git

dmaengine: avoid map_cnt overflow with CONFIG_DMA_ENGINE_RAID

When CONFIG_DMA_ENGINE_RAID is enabled, unmap pool size can reach to
256. But in struct dmaengine_unmap_data, map_cnt is only u8, wrapping
to 0, if the unmap pool is maximally used. This triggers BUG() when
struct dmaengine_unmap_data is freed. Use u16 to fix the problem.

Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
---

diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index f838764993eb..861be5cab1df 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -470,7 +470,11 @@ typedef void (*dma_async_tx_callback_result)(void *dma_async_param,
 				const struct dmaengine_result *result);
 
 struct dmaengine_unmap_data {
+#if IS_ENABLED(CONFIG_DMA_ENGINE_RAID)
+	u16 map_cnt;
+#else
 	u8 map_cnt;
+#endif
 	u8 to_cnt;
 	u8 from_cnt;
 	u8 bidi_cnt;