[PATCH 01/21] dmaengine: apple-admac: Annotate struct admac_data with __counted_by

Kees Cook
2023-08-18T00:00:08Z

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 admac_data.

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

Cc: Vinod Koul <vkoul@kernel.org>
Cc: Hector Martin <marcan@marcan.st>
Cc: Sven Peter <sven@svenpeter.dev>
Cc: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Cc: asahi@lists.linux.dev
Cc: linux-arm-kernel@lists.infradead.org
Cc: dmaengine@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
drivers/dma/apple-admac.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/apple-admac.c b/drivers/dma/apple-admac.c
index 3af795635c5c..ff46260b6ebc 100644
--- a/drivers/dma/apple-admac.c
+++ b/drivers/dma/apple-admac.c
@@ -128,7 +128,7 @@ struct admac_data {
int irq;
int irq_index;
int nchannels;
- struct admac_chan channels[];
+ struct admac_chan channels[] __counted_by(nchannels);
};

struct admac_tx {
--
2.34.1