[PATCH 04/21] dmaengine: fsl-edma: Annotate struct fsl_edma_desc with __counted_by

Kees Cook
2023-08-18T00:00:12Z

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 fsl_edma_desc.

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

Cc: Vinod Koul <vkoul@kernel.org>
Cc: dmaengine@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
drivers/dma/fsl-edma-common.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/fsl-edma-common.h b/drivers/dma/fsl-edma-common.h
index 004ec4a6bc86..fdbc79787643 100644
--- a/drivers/dma/fsl-edma-common.h
+++ b/drivers/dma/fsl-edma-common.h
@@ -135,7 +135,7 @@ struct fsl_edma_desc {
bool iscyclic;
enum dma_transfer_direction dirn;
unsigned int n_tcds;
- struct fsl_edma_sw_tcd tcd[];
+ struct fsl_edma_sw_tcd tcd[] __counted_by(n_tcds);
};

enum edma_version {
--
2.34.1