Extend the `module!` macro with support module parameters. Also add some string to integer parsing functions. Based on the original module parameter support by Miguel [1], later extended and generalized by Adam for more types [2][3]. Originally tracked at [4]. Link: https://github.com/Rust-for-Linux/linux/pull/7 [1] Link: https://github.com/Rust-for-Linux/linux/pull/82 [2] Link: https://github.com/Rust-for-Linux/linux/pull/87 [3] Link: https://github.com/Rust-for-Linux/linux/issues/11 [4] Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxx> --- Changes in v17: - Fix drop impl of `SetOnce` so that it works with `UnsafeCell<MaybeUninit<_>>`. - Slightly reword safety framework in `SetOnce`. - Rebase on atomic series v6. - Link to v16: https://lore.kernel.org/r/20250709-module-params-v3-v16-0-4f926bcccb50@xxxxxxxxxx Changes in v16: - Normalize imports in `set_once.rs`. - Use `UnsafeCell<MaybeUninit<T>>` rather than `Opaque<T>` for `SetOnce`. - Use regular load in drop of `SetOnce`. - Update attribution paragraph in cover letter with details from Miguel. - Remove stray TODO in `set_once.rs` - Link to v15: https://lore.kernel.org/r/20250707-module-params-v3-v15-0-c1f4269a57b9@xxxxxxxxxx Changes in v15: - Rebase on v6.16-rc5. - Dedent code in module macro for better formatting. - Rename `OnceLock` to `SetOnce`. - Use "being initialized" rather than "being mutably accessed" when describing initialization state of `OnceLock`. - Use `Relaxed` ordering when transitioning to exclusive access in `OnceLock`. - Add drop implementation for `OnceLock`. - Re-export `OnceLock` from `kernel::sync` module. - Improve indentation of in macro code. Prefix `cfg` to `::core::cfg` in macro code. - Use `core::ptr::from_ref` rather than `as` casts. - Hide `KernelParam` instances behind `const _: ()` blocks. - Rename `ModuleParamAccess::get` to `ModuleParamAccess::value`. - Rename `RacyKernelParam` to `KernelParam`. - Remove `ModuleParam::Value`. - Move `copy` implementation of `OnceLock`. - Update safety comments and invariants of `OnceLock`. - Link to v14: https://lore.kernel.org/r/20250702-module-params-v3-v14-0-5b1cc32311af@xxxxxxxxxx Note: This series now depends on the atomics series [1]. [1] https://lore.kernel.org/all/20250618164934.19817-1-boqun.feng@xxxxxxxxx Changes in v14: - Remove unnecessary `crate::` prefix from `module_param::set_param`. - Make `FromStrRadix` safe again by moving unsafe blocks to macro implementation (thanks Benno). - Use `core::ptr::write` in `set_param` and drop safety requirement regarding initialization. - Add a TODO to use `SyncUnsafeCell` for `ModuleParamAccess` when available. - Add a NOTE regarding `Copy` bound on `ModuleParam`. - Remove `'static` lifetime qualifier from `ModuleParam::try_from_param_arg` argument. - Fix a typo in the safety requirements for `set_param`. - Remove unused `#[macro_export]` attribute. - Remove obsolete documentation for `ModuleParam::try_from_param_arg`. - Make `RacyKernelParam` tuple field private. - Introduce `OnceLock` and use that to synchronize population of parameter values. - Link to v13: https://lore.kernel.org/r/20250612-module-params-v3-v13-0-bc219cd1a3f8@xxxxxxxxxx Changes in v13: - remove absolute path for `ffi` types. - Split patch 2 into 4 separate patches. - Overhaul safety framework for `set_param`. - Remove generated docs for `kernel_param_ops`. - Move `parse_int` to separate file. - Rebase on v6.16-rc1 - Link to v12: https://lore.kernel.org/r/20250506-module-params-v3-v12-0-c04d80c8a2b1@xxxxxxxxxx Changes in v12: - Assign through pointer rather than using `core::ptr::replace`. - Prevent a potential use-after-free during module teardown. - Link to v11: https://lore.kernel.org/r/20250502-module-params-v3-v11-0-6096875a2b78@xxxxxxxxxx Changes in v11: - Apply a few nits from Miguel. - Link to v10: https://lore.kernel.org/r/20250501-module-params-v3-v10-0-4da485d343d5@xxxxxxxxxx Changes in v10: - Apply fixups from Miguel: - Add integer type suffixes to `assert!` in tests. - Fix links to docs.kernel.org. - Applyy markdown and intra-doc links where possible. - Change to `///` for `mod` docs. - Slightly reword a comment. - Pluralize "Examples" section name. - Hide `use`s in example. - Removed `#[expect]` for the `rusttest` target. - Link to v9: https://lore.kernel.org/r/20250321-module-params-v3-v9-0-28b905f2e345@xxxxxxxxxx Changes in v9: - Remove UB when parsing the minimum integer values. - Make `FromStr` trait unsafe, since wrong implementations can cause UB. - Drop patches that were applied to rust-next. - Link to v8: https://lore.kernel.org/r/20250227-module-params-v3-v8-0-ceeee85d9347@xxxxxxxxxx Changes in v8: - Change print statement in sample to better communicate parameter name. - Use imperative mode in commit messages. - Remove prefix path from `EINVAL`. - Change `try_from_param_arg` to accept `&BStr` rather than `&[u8]`. - Parse integers without 128 bit integer types. - Seal trait `FromStrRadix`. - Strengthen safety requirement of `set_param`. - Remove comment about Display and `PAGE_SIZE`. - Add note describing why `ModuleParamAccess` is pub. - Typo and grammar fixes for documentation. - Update MAINTAINERS with rust module files. - Link to v7: https://lore.kernel.org/r/20250218-module-params-v3-v7-0-5e1afabcac1b@xxxxxxxxxx Changes in v7: - Remove dependency on `pr_warn_once` patches, replace with TODO. - Rework `ParseInt::from_str` to avoid allocating. - Add a comment explaining how we parse "0". - Change trait bound on `Index` impl for `BStr` to match std library approach. - Link to v6: https://lore.kernel.org/r/20250211-module-params-v3-v6-0-24b297ddc43d@xxxxxxxxxx Changes in v6: - Fix a bug that prevented parsing of negative default values for parameters in the `module!` macro. - Fix a bug that prevented parsing zero in `strip_radix`. Also add a test case for this. - Add `AsRef<BStr>` for `[u8]` and `BStr`. - Use `impl AsRef<BStr>` as type of prefix in `BStr::strip_prefix`. - Link to v5: https://lore.kernel.org/r/20250204-module-params-v3-v5-0-bf5ec2041625@xxxxxxxxxx Changes in v5: - Fix a typo in a safety comment in `set_param`. - Use a match statement in `parse_int::strip_radix`. - Add an implementation of `Index` for `BStr`. - Fix a logic inversion bug where parameters would not be parsed. - Use `kernel::ffi::c_char` in `set_param` rather than the one in `core`. - Use `kernel::c_str!` rather than `c"..."` literal in module macro. - Rebase on v6.14-rc1. - Link to v4: https://lore.kernel.org/r/20250109-module-params-v3-v4-0-c208bcfbe11f@xxxxxxxxxx Changes in v4: - Add module maintainers to Cc list (sorry) - Add a few missing [`doc_links`] - Add panic section to `expect_string_field` - Fix a typo in safety requirement of `module_params::free` - Change `assert!` to `pr_warn_once!` in `module_params::set_param` - Remove `module_params::get_param` and install null pointer instead - Remove use of the unstable feature `sync_unsafe_cell` - Link to v3: https://lore.kernel.org/r/20241213-module-params-v3-v3-0-485a015ac2cf@xxxxxxxxxx Changes in v3: - use `SyncUnsafeCell` rather than `static mut` and simplify parameter access - remove `Display` bound from `ModuleParam` - automatically generate documentation for `PARAM_OPS_.*` - remove `as *const _ as *mut_` phrasing - inline parameter name in struct instantiation in `emit_params` - move `RacyKernelParam` out of macro template - use C string literals rather than byte string literals with explicit null - template out `__{name}_{param_name}` in `emit_param` - indent template in `emit_params` - use let-else expression in `emit_params` to get rid of an indentation level - document `expect_string_field` - move invication of `impl_int_module_param` to be closer to macro def - move attributes after docs in `make_param_ops` - rename `impl_module_param` to impl_int_module_param` - use `ty` instead of `ident` in `impl_parse_int` - use `BStr` instead of `&str` for string manipulation - move string parsing functions to seperate patch and add examples, fix bugs - degrade comment about future support from doc comment to regular comment - remove std lib path from `Sized` marker - update documentation for `trait ModuleParam` - Link to v2: https://lore.kernel.org/all/20240819133345.3438739-1-nmi@xxxxxxxxxxxx/ Changes in v2: - Remove support for params without values (`NOARG_ALLOWED`). - Improve documentation for `try_from_param_arg`. - Use prelude import. - Refactor `try_from_param_arg` to return `Result`. - Refactor `ParseInt::from_str` to return `Result`. - Move C callable functions out of `ModuleParam` trait. - Rename literal string field parser to `expect_string_field`. - Move parameter parsing from generation to parsing stage. - Use absolute type paths in macro code. - Inline `kparam`and `read_func` values. - Resolve TODO regarding alignment attributes. - Remove unnecessary unsafe blocks in macro code. - Improve error message for unrecognized parameter types. - Do not use `self` receiver when reading parameter value. - Add parameter documentation to `module!` macro. - Use empty `enum` for parameter type. - Use `addr_of_mut` to get address of parameter value variable. - Enabled building of docs for for `module_param` module. - Link to v1: https://lore.kernel.org/rust-for-linux/20240705111455.142790-1-nmi@xxxxxxxxxxxx/ --- Andreas Hindborg (7): rust: sync: add `SetOnce` rust: str: add radix prefixed integer parsing functions rust: introduce module_param module rust: module: use a reference in macros::module::module rust: module: update the module macro with module parameter support rust: samples: add a module parameter to the rust_minimal sample modules: add rust modules files to MAINTAINERS MAINTAINERS | 2 + rust/kernel/lib.rs | 1 + rust/kernel/module_param.rs | 181 +++++++++++++++++++++++++++++++++++++++ rust/kernel/str.rs | 2 + rust/kernel/str/parse_int.rs | 148 ++++++++++++++++++++++++++++++++ rust/kernel/sync.rs | 2 + rust/kernel/sync/set_once.rs | 125 +++++++++++++++++++++++++++ rust/macros/helpers.rs | 25 ++++++ rust/macros/lib.rs | 31 +++++++ rust/macros/module.rs | 198 ++++++++++++++++++++++++++++++++++++++----- samples/rust/rust_minimal.rs | 10 +++ 11 files changed, 705 insertions(+), 20 deletions(-) --- base-commit: 47633099a672fc7bfe604ef454e4f116e2c954b1 change-id: 20241211-module-params-v3-ae7e5c8d8b5a prerequisite-message-id: <20250710060052.11955-1-boqun.feng@xxxxxxxxx> prerequisite-patch-id: 28896267479b4eb64b31c7f0369398c3d45381d5 prerequisite-patch-id: d2f889e59033a98b2939ec8b1f73b82026eeca57 prerequisite-patch-id: 820b700bc77f6ab3b7ab41056675f8e8f27ca924 prerequisite-patch-id: 8050edc4035cf1b57251d8de496b890b87918cb9 prerequisite-patch-id: ce22d95bad2cf5b701db6d62ec3dd8e5f47d8af0 prerequisite-patch-id: 5755c226b2678a53a8cfd7d09f90743c1d6f6ae4 prerequisite-patch-id: 766b6439b20cb954b3434830603cf88626a35310 prerequisite-patch-id: 98fffa4e658617923ab1c360dc40bacb9d741e3c prerequisite-patch-id: b393394acd88dae6dfe76ac10af2e9469a08fdc4 Best regards, -- Andreas Hindborg <a.hindborg@xxxxxxxxxx>
