[PATCH 09/21] dmaengine: sf-pdma: Annotate struct sf_pdma 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 sf_pdma.

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

Cc: Vinod Koul <vkoul at kernel.org>
Cc: Green Wan <green.wan at sifive.com>
Cc: dmaengine at vger.kernel.org
Signed-off-by: Kees Cook <keescook at chromium.org>
---
 drivers/dma/sf-pdma/sf-pdma.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/sf-pdma/sf-pdma.h b/drivers/dma/sf-pdma/sf-pdma.h
index 5c398a83b491..d05772b5d8d3 100644
--- a/drivers/dma/sf-pdma/sf-pdma.h
+++ b/drivers/dma/sf-pdma/sf-pdma.h
@@ -113,7 +113,7 @@ struct sf_pdma {
 	void __iomem            *membase;
 	void __iomem            *mappedbase;
 	u32			n_chans;
-	struct sf_pdma_chan	chans[];
+	struct sf_pdma_chan	chans[] __counted_by(n_chans);
 };
 
 #endif /* _SF_PDMA_H */
-- 
2.34.1