[PATCH 05/21] dmaengine: hisilicon: Annotate struct hisi_dma_dev with __counted_by

[Kees Cook]

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct hisi_dma_dev.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Vinod Koul <vkoul@xxxxxxxxxx>
Cc: Zhou Wang <wangzhou1@xxxxxxxxxxxxx>
Cc: Jie Hai <haijie1@xxxxxxxxxx>
Cc: dmaengine@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 drivers/dma/hisi_dma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/hisi_dma.c b/drivers/dma/hisi_dma.c
index c1350a36fddd..4c47bff81064 100644
--- a/drivers/dma/hisi_dma.c
+++ b/drivers/dma/hisi_dma.c
@@ -163,7 +163,7 @@ struct hisi_dma_dev {
 	u32 chan_depth;
 	enum hisi_dma_reg_layout reg_layout;
 	void __iomem *queue_base; /* queue region start of register */
-	struct hisi_dma_chan chan[];
+	struct hisi_dma_chan chan[] __counted_by(chan_num);
 };
 
 #ifdef CONFIG_DEBUG_FS
-- 
2.34.1