[PATCH 20/21] dmaengine: uniphier-xdmac: Annotate struct uniphier_xdmac_device 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 uniphier_xdmac_device.

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

Cc: Vinod Koul <vkoul at kernel.org>
Cc: Kunihiko Hayashi <hayashi.kunihiko at socionext.com>
Cc: Masami Hiramatsu <mhiramat at kernel.org>
Cc: dmaengine at vger.kernel.org
Cc: linux-arm-kernel at lists.infradead.org
Signed-off-by: Kees Cook <keescook at chromium.org>
---
 drivers/dma/uniphier-xdmac.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/uniphier-xdmac.c b/drivers/dma/uniphier-xdmac.c
index dd51522879a7..3a8ee2b173b5 100644
--- a/drivers/dma/uniphier-xdmac.c
+++ b/drivers/dma/uniphier-xdmac.c
@@ -97,7 +97,7 @@ struct uniphier_xdmac_device {
 	struct dma_device ddev;
 	void __iomem *reg_base;
 	int nr_chans;
-	struct uniphier_xdmac_chan channels[];
+	struct uniphier_xdmac_chan channels[] __counted_by(nr_chans);
 };
 
 static struct uniphier_xdmac_chan *
-- 
2.34.1