2023-10-03 23:28:08

by Kees Cook

Subject: [PATCH] dmaengine: fsl-edma: Annotate struct struct fsl_edma_engine with __counted_by

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 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 struct fsl_edma_engine.

Cc: Vinod Koul <[email protected]>
Cc: [email protected]
Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by: Kees Cook <[email protected]>
---
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 40d50cc3d75a..bb5221158a77 100644
--- a/drivers/dma/fsl-edma-common.h
+++ b/drivers/dma/fsl-edma-common.h
@@ -225,7 +225,7 @@ struct fsl_edma_engine {
bool big_endian;
struct edma_regs regs;
u64 chan_masked;
- struct fsl_edma_chan chans[];
+ struct fsl_edma_chan chans[] __counted_by(n_chans);
};

#define edma_read_tcdreg(chan, __name) \
--
2.34.1

2023-10-04 04:25:29

by Gustavo A. R. Silva

Subject: Re: [PATCH] dmaengine: fsl-edma: Annotate struct struct fsl_edma_engine with __counted_by

On 10/4/23 01:27, 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 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 struct fsl_edma_engine.
>
> Cc: Vinod Koul <[email protected]>
> Cc: [email protected]
> Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
> Signed-off-by: Kees Cook <[email protected]>

Reviewed-by: Gustavo A. R. Silva <[email protected]>

Thanks
--
Gustavo

> ---
> 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 40d50cc3d75a..bb5221158a77 100644
> --- a/drivers/dma/fsl-edma-common.h
> +++ b/drivers/dma/fsl-edma-common.h
> @@ -225,7 +225,7 @@ struct fsl_edma_engine {
> bool big_endian;
> struct edma_regs regs;
> u64 chan_masked;
> - struct fsl_edma_chan chans[];
> + struct fsl_edma_chan chans[] __counted_by(n_chans);
> };
>
> #define edma_read_tcdreg(chan, __name) \

2023-10-04 14:29:25

by Vinod Koul

Subject: Re: [PATCH] dmaengine: fsl-edma: Annotate struct struct fsl_edma_engine with __counted_by

On Tue, 03 Oct 2023 16:27:56 -0700, 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 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 struct fsl_edma_engine.
>
> [...]

Applied, thanks!

[1/1] dmaengine: fsl-edma: Annotate struct struct fsl_edma_engine with __counted_by
commit: c223bafdcbd51506df00509088efc62e08ef6c3f

Best regards,
--
~Vinod