Re: [PATCH] dma: ste_dma40: Remove VLA usage

[Arnd Bergmann]

On Fri, Jun 29, 2018 at 8:51 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> In the quest to remove all stack VLA usage from the kernel[1], this
> switches to using a pre-allocated scratch register space, set up with
> all other other allocations.
>
> [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@xxxxxxxxxxxxxx
>
> Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Cc: Vinod Koul <vkoul@xxxxxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: dmaengine@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

I looked too long at this one, in short:

- Your change looks correct to me
- It could be done better in many ways, all of which would
  involve cleaning up some of the existing code in the process
- Nobody uses this driver in practice, as the hardware platform
  was a dead end

Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>