[PATCH v4 1/5] gcc-plugins: arm-ssp: Prepare for THREAD_INFO_IN_TASK support

[Linus Walleij]

Hi Ard,

thanks for this patch series!

On Mon, Sep 13, 2021 at 12:40 PM Ard Biesheuvel <ardb at kernel.org> wrote:

>  config STACKPROTECTOR_PER_TASK
>         bool "Use a unique stack canary value for each task"
> -       depends on GCC_PLUGINS && STACKPROTECTOR && SMP && !XIP_DEFLATED_DATA
> +       depends on GCC_PLUGINS && STACKPROTECTOR && THREAD_INFO_IN_TASK && !XIP_DEFLATED_DATA
>         select GCC_PLUGIN_ARM_SSP_PER_TASK

Am I reading this right that STACKPROTECTOR_PER_TASK
was available for ARMv6 with SMP before this
change and after this change it will only be available for
ARMv7 since THREAD_INFO_IN_TASK which is now a dependency
will only be available for ARMv7 (or ARMv6k)?

I suppose this is a reasonable compromise, as I don't use it or need
it on my ARM PB11MPCore and neither do I think the Oxnas router,
but we should write this explicitly in the commit message.

Yours,
Linus Walleij