Re: [PATCH] spi: mchp-pci1xxxx: Annotate struct pci1xxxx_spi with __counted_by

From: Gustavo A. R. Silva
Date: Sat Sep 23 2023 - 05:00:15 EST


On Fri, Sep 22, 2023 at 10:53:23AM -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 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 pci1xxxx_spi.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Mark Brown <broonie@xxxxxxxxxx>
> Cc: linux-spi@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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

Thanks
--
Gustavo

> ---
> drivers/spi/spi-pci1xxxx.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/spi/spi-pci1xxxx.c b/drivers/spi/spi-pci1xxxx.c
> index 3638e974f5d4..5b2d3e4e21b7 100644
> --- a/drivers/spi/spi-pci1xxxx.c
> +++ b/drivers/spi/spi-pci1xxxx.c
> @@ -77,7 +77,7 @@ struct pci1xxxx_spi {
> struct pci_dev *dev;
> u8 total_hw_instances;
> void __iomem *reg_base;
> - struct pci1xxxx_spi_internal *spi_int[];
> + struct pci1xxxx_spi_internal *spi_int[] __counted_by(total_hw_instances);
> };
>
> static const struct pci_device_id pci1xxxx_spi_pci_id_table[] = {
> --
> 2.34.1
>
>