Currently, we don't support MODVERSIONS for Rust symbols. For users that want to use Rust in the kernel but for whom MODVERSIONS is required, this allows the use of built-in Rust code even with MODVERSIONS enabled. It may additionally allow code-size reduction by avoiding exporting symbols that won't be used without Rust modules. Signed-off-by: Matthew Maurer <mmaurer@xxxxxxxxxx> --- init/Kconfig | 21 +++++++++++++++++---- kernel/module/Kconfig | 1 + rust/exports.c | 4 ++++ 3 files changed, 22 insertions(+), 4 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index 9ffb103fc927..6912dbbee3f1 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1885,7 +1885,6 @@ config RUST bool "Rust support" depends on HAVE_RUST depends on RUST_IS_AVAILABLE - depends on !MODVERSIONS depends on !GCC_PLUGINS depends on !RANDSTRUCT depends on !DEBUG_INFO_BTF || PAHOLE_HAS_LANG_EXCLUDE @@ -1896,13 +1895,27 @@ config RUST This allows other Rust-related options, like drivers written in Rust, to be selected. - It is also required to be able to load external kernel modules - written in Rust. - See Documentation/rust/ for more information. If unsure, say N. +config RUST_MODULES + bool "Rust Module Support" + depends on RUST + depends on MODULES + rust_modules + help + Enables support for Rust Modules in the kernel. + + This is required to load external kernel modules written in Rust. + + The two primary reasons to consider disabling this are: + * Allow MODVERSIONS support + * Allow additional code to be optimized out by the compiler if you + know that you'll only be using built-in Rust code. + + If unsure, say Y. + config RUSTC_VERSION_TEXT string depends on RUST diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig index 0ea1b2970a23..a76128887618 100644 --- a/kernel/module/Kconfig +++ b/kernel/module/Kconfig @@ -158,6 +158,7 @@ config MODULE_UNLOAD_TAINT_TRACKING shown. If unsure, say N. config MODVERSIONS + depends on !RUST_MODULES bool "Module versioning support" help Usually, you have to use modules compiled with your kernel. diff --git a/rust/exports.c b/rust/exports.c index 83e2a7070cae..96b706048ed4 100644 --- a/rust/exports.c +++ b/rust/exports.c @@ -13,7 +13,11 @@ #include <linux/module.h> +#ifdef CONFIG_RUST_MODULES #define EXPORT_SYMBOL_RUST_GPL(sym) extern int sym; EXPORT_SYMBOL_GPL(sym) +#else +#define EXPORT_SYMBOL_RUST_GPL(sym) +#endif #include "exports_core_generated.h" #include "exports_alloc_generated.h" -- 2.42.0.869.gea05f2083d-goog
