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@kernel.org>
Cc: linux-spi@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 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

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@kernel.org>
> Cc: linux-spi@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

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
> 
>

On Fri, 22 Sep 2023 10:53:23 -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.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: mchp-pci1xxxx: Annotate struct pci1xxxx_spi with __counted_by
      commit: c40897f4730f4f9a37f3155e3e0452e1c8da37b4

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark