This series extends the `module!` macro with support module parameters. It also adds some string to integer parsing functions and updates `BStr` with a method to strip a string prefix. This series stated out as code by Adam Bratschi-Kaye lifted from the original `rust` branch [1]. After a bit of discussion on v3 about whether or not module parameters is a good idea, it seems that module parameters in Rust has a place in the kernel for now. This series is a dependency for `rnull`, the Rust null block driver [2]. --- Module subsystem people: how do you want to handle merging of the patches and subsequent maintenance of code? I think we discussed you guys taking this under the current module maintainer entry? If that is correct, will you add the new files to your entry yourself, or should I include an update to MAINTAINERS in this series? If prefer another solution, let me know and we can figure that out. To: Miguel Ojeda <ojeda@xxxxxxxxxx> To: Alex Gaynor <alex.gaynor@xxxxxxxxx> To: Boqun Feng <boqun.feng@xxxxxxxxx> To: Gary Guo <gary@xxxxxxxxxxx> To: Björn Roy Baron <bjorn3_gh@xxxxxxxxxxxxxx> To: Benno Lossin <benno.lossin@xxxxxxxxx> To: Alice Ryhl <aliceryhl@xxxxxxxxxx> To: Masahiro Yamada <masahiroy@xxxxxxxxxx> To: Nathan Chancellor <nathan@xxxxxxxxxx> To: Nicolas Schier <nicolas@xxxxxxxxx> To: Luis Chamberlain <mcgrof@xxxxxxxxxx> Cc: Trevor Gross <tmgross@xxxxxxxxx> Cc: Adam Bratschi-Kaye <ark.email@xxxxxxxxx> Cc: rust-for-linux@xxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Cc: linux-kbuild@xxxxxxxxxxxxxxx Cc: Petr Pavlu <petr.pavlu@xxxxxxxx> Cc: Sami Tolvanen <samitolvanen@xxxxxxxxxx> Cc: Daniel Gomez <da.gomez@xxxxxxxxxxx> Cc: Simona Vetter <simona.vetter@xxxxxxxx> Cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: linux-modules@xxxxxxxxxxxxxxx Link: https://github.com/Rust-for-Linux/linux/tree/bc22545f38d74473cfef3e9fd65432733435b79f [1] Link: https://git.kernel.org/pub/scm/linux/kernel/git/a.hindborg/linux.git/log/?h=rnull [2] Signed-off-by: Andreas Hindborg <a.hindborg@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 (6): rust: str: implement `PartialEq` for `BStr` rust: str: implement `Index` for `BStr` rust: str: implement `AsRef<BStr>` for `[u8]` and `BStr` rust: str: implement `strip_prefix` for `BStr` rust: str: add radix prefixed integer parsing functions rust: add parameter support to the `module!` macro rust/kernel/lib.rs | 1 + rust/kernel/module_param.rs | 226 +++++++++++++++++++++++++++++++++++++++++++ rust/kernel/str.rs | 163 +++++++++++++++++++++++++++++++ rust/macros/helpers.rs | 25 +++++ rust/macros/lib.rs | 31 ++++++ rust/macros/module.rs | 191 ++++++++++++++++++++++++++++++++---- samples/rust/rust_minimal.rs | 10 ++ 7 files changed, 629 insertions(+), 18 deletions(-) --- base-commit: 379487e17ca406b47392e7ab6cf35d1c3bacb371 change-id: 20241211-module-params-v3-ae7e5c8d8b5a Best regards, -- Andreas Hindborg <a.hindborg@xxxxxxxxxx>
