Re: [PATCH 17/21] dmaengine: ti: edma: Annotate struct edma_desc with __counted_by

From: Gustavo A. R. Silva
Date: Thu Aug 17 2023 - 23:25:41 EST




On 8/17/23 17:58, Kees Cook wrote:
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 edma_desc.

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

Cc: Vinod Koul <vkoul@xxxxxxxxxx>
Cc: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx>
Cc: dmaengine@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>

Thanks
--
Gustavo

---
drivers/dma/ti/edma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/ti/edma.c b/drivers/dma/ti/edma.c
index aa8e2e8ac260..9c2b2c4c3882 100644
--- a/drivers/dma/ti/edma.c
+++ b/drivers/dma/ti/edma.c
@@ -202,7 +202,7 @@ struct edma_desc {
u32 residue;
u32 residue_stat;
- struct edma_pset pset[];
+ struct edma_pset pset[] __counted_by(pset_nr);
};
struct edma_cc;