On Mon Jun 22, 2026 at 3:44 AM BST, Alvin Sun wrote: > Since `const_refs_to_static` has been stable as of the MSRV bump, a > `ThisModule` pointer can now be used in const contexts. > > Add a `THIS_MODULE` const to the `ModuleMetadata` trait so that modules > can provide their `ThisModule` pointer in const contexts such as static > `file_operations`. > > Move the `THIS_MODULE` static from the `module!` macro into the > `ModuleMetadata` impl, add a `this_module()` helper, and update `__init` > to use it.
Doesn't this break existing users of THIS_MODULE? Binder, rnull and configfs macros are using it. Best, Gary > > Signed-off-by: Alvin Sun <[email protected]> > --- > rust/kernel/lib.rs | 8 ++++++++ > rust/macros/module.rs | 34 +++++++++++++++++----------------- > 2 files changed, 25 insertions(+), 17 deletions(-) > > diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs > index b72b2fbe046d6..50f5a7b5f028e 100644 > --- a/rust/kernel/lib.rs > +++ b/rust/kernel/lib.rs > @@ -184,6 +184,14 @@ fn init(module: &'static ThisModule) -> impl > pin_init::PinInit<Self, error::Erro > pub trait ModuleMetadata { > /// The name of the module as specified in the `module!` macro. > const NAME: &'static crate::str::CStr; > + > + /// The module's `THIS_MODULE` pointer. > + const THIS_MODULE: ThisModule; > +} > + > +/// Returns a reference to the `THIS_MODULE` of the given module type. > +pub const fn this_module<M: ModuleMetadata>() -> &'static ThisModule { > + &M::THIS_MODULE > } > > /// Equivalent to `THIS_MODULE` in the C API. > diff --git a/rust/macros/module.rs b/rust/macros/module.rs > index 06c18e2075083..b9fdee2f2af47 100644 > --- a/rust/macros/module.rs > +++ b/rust/macros/module.rs > @@ -497,28 +497,28 @@ pub(crate) fn module(info: ModuleInfo) -> > Result<TokenStream> { > /// Used by the printing macros, e.g. [`info!`]. > const __LOG_PREFIX: &[u8] = #name_cstr.to_bytes_with_nul(); > > - // SAFETY: `__this_module` is constructed by the kernel at load time > and will not be > - // freed until the module is unloaded. > - #[cfg(MODULE)] > - static THIS_MODULE: ::kernel::ThisModule = unsafe { > - extern "C" { > - static __this_module: > ::kernel::types::Opaque<::kernel::bindings::module>; > - }; > - > - ::kernel::ThisModule::from_ptr(__this_module.get()) > - }; > - > - #[cfg(not(MODULE))] > - static THIS_MODULE: ::kernel::ThisModule = unsafe { > - ::kernel::ThisModule::from_ptr(::core::ptr::null_mut()) > - }; > - > /// The `LocalModule` type is the type of the module created by > `module!`, > /// `module_pci_driver!`, `module_platform_driver!`, etc. > type LocalModule = #type_; > > impl ::kernel::ModuleMetadata for #type_ { > const NAME: &'static ::kernel::str::CStr = #name_cstr; > + > + #[cfg(MODULE)] > + const THIS_MODULE: ::kernel::ThisModule = { > + extern "C" { > + static __this_module: > ::kernel::types::Opaque<::kernel::bindings::module>; > + } > + > + // SAFETY: `__this_module` is constructed by the kernel at > load time > + // and lives until the module is unloaded. > + unsafe { ::kernel::ThisModule::from_ptr(__this_module.get()) > } > + }; > + > + #[cfg(not(MODULE))] > + const THIS_MODULE: ::kernel::ThisModule = unsafe { > + ::kernel::ThisModule::from_ptr(::core::ptr::null_mut()) > + }; > } > > // Double nested modules, since then nobody can access the public > items inside. > @@ -616,7 +616,7 @@ pub extern "C" fn #ident_exit() { > /// This function must only be called once. > unsafe fn __init() -> ::kernel::ffi::c_int { > let initer = <super::super::LocalModule as > ::kernel::InPlaceModule>::init( > - &super::super::THIS_MODULE > + ::kernel::this_module::<super::super::LocalModule>() > ); > // SAFETY: No data race, since `__MOD` can only be > accessed by this module > // and there only `__init` and `__exit` access it. These > functions are only
