Re: [PATCH 09/21] dmaengine: sf-pdma: Annotate struct sf_pdma with __counted_by

From: Gustavo A. R. Silva
Date: Thu Aug 17 2023 - 21:25:31 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 sf_pdma.

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

Cc: Vinod Koul <vkoul@xxxxxxxxxx>
Cc: Green Wan <green.wan@xxxxxxxxxx>
Cc: dmaengine@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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

Thanks
--
Gustavo

---
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 */