Re: [PATCH RESEND v3] hardening: Default randstruct off with rust for better allmodconfig support

[Paul Moore]

On Wed, Aug 5, 2026 at 1:02 PM Mark Brown <broonie@xxxxxxxxxx> wrote:
>
> Currently randstruct does not support rust so we have Kconfig dependencies
> which prevent rust being enabled when randstruct is. Unfortunately this
> prevents rust being enabled in allmodconfig, our standard coverage build.
> randstruct gets turned on by default, then the dependency on !RANDSTRUCT
> causes rust to get disabled.
>
> Work around this by disabling randstruct by default if we have a usable
> rust toolchain and rust support for the architecture, circular
> dependencies prevent us directly depending on !RUST. This means we might
> end up with a configuration that disables both rust and randstruct but
> hopefully it's more likely go give the expected result.
>
> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
> ---
> Changes in v3:
> - Rebase onto v7.2-rc1.
> - Link to v2: https://patch.msgid.link/20260605-rust-reverse-randstruct-dep-v2-1-93d38023b6f9@xxxxxxxxxx
>
> Changes in v2:
> - Add a HAVE_RUST in there too.
> - Link to v1: https://patch.msgid.link/20260605-rust-reverse-randstruct-dep-v1-1-45ce9ee8d0d1@xxxxxxxxxx
> ---
>  security/Kconfig.hardening | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

FYI, I believe Kees has been away from email for a bit, but my
understanding is that will be changing soon.

> diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening
> index 6923036e1a2f..81c81ad983ad 100644
> --- a/security/Kconfig.hardening
> +++ b/security/Kconfig.hardening
> @@ -278,7 +278,7 @@ config CC_HAS_RANDSTRUCT
>
>  choice
>         prompt "Randomize layout of sensitive kernel structures"
> -       default RANDSTRUCT_FULL if COMPILE_TEST && (GCC_PLUGINS || CC_HAS_RANDSTRUCT)
> +       default RANDSTRUCT_FULL if !(RUST_IS_AVAILABLE && HAVE_RUST) && COMPILE_TEST && (GCC_PLUGINS || CC_HAS_RANDSTRUCT)
>         default RANDSTRUCT_NONE
>         help
>           If you enable this, the layouts of structures that are entirely
>
> ---
> base-commit: dc59e4fea9d83f03bad6bddf3fa2e52491777482
> change-id: 20260605-rust-reverse-randstruct-dep-5a504c861128

-- 
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