[PATCH v5 1/5] gcc-plugins: arm-ssp: Prepare for THREAD_INFO_IN_TASK support

[Linus Walleij]

On Sat, Sep 18, 2021 at 10:44 AM Ard Biesheuvel <ardb at kernel.org> wrote:

> We will be enabling THREAD_INFO_IN_TASK support for ARM, which means
> that we can no longer load the stack canary value by masking the stack
> pointer and taking the copy that lives in thread_info. Instead, we will
> be able to load it from the task_struct directly, by using the TPIDRURO
> register which will hold the current task pointer when
> THREAD_INFO_IN_TASK is in effect. This is much more straight-forward,
> and allows us to declutter this code a bit while at it.
>
> Note that this means that ARMv6 (non-v6K) SMP systems can no longer use
> this feature, but those are quite rare to begin with, so this is a
> reasonable trade off.
>
> Reviewed-by: Kees Cook <keescook at chromium.org>
> Signed-off-by: Ard Biesheuvel <ardb at kernel.org>

Reviewed-by: Linus Walleij <linus.walleij at linaro.org>

Yours,
Linus Walleij