Hi, On Thu, Feb 27, 2025 at 03:38:06PM +0100, Andreas Hindborg wrote: > Extend the `module!` macro with support module parameters. Also add some string > to integer parsing functions and updates `BStr` with a method to strip a string > prefix. > > Based on code by Adam Bratschi-Kaye lifted from the original `rust` branch [1]. > > Link: https://github.com/Rust-for-Linux/linux/tree/bc22545f38d74473cfef3e9fd65432733435b79f [1] > Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxx> I've tested this series including the following patches from Andreas' tree [1] as dependency for module testing parameters with the Rust Null Block driver: [1] https://web.git.kernel.org/pub/scm/linux/kernel/git/a.hindborg/linux.git/log/?h=rnull-v6.14-rc1 51d304103b7f rust: refactor: rename `RawWriter` to `BufferWriter` 544811b24574 LIST: [PATCH v2 1/3] rust: sync: change `<Arc<T> as ForeignOwnable>::PointedTo` to `T` 3f097abd58de LIST: [PATCH v15 1/3] rust: types: add `ForeignOwnable::PointedTo` 0525eda0ff8d LIST: [PATCH v7 3/14] rust: sync: add `Arc::as_ptr` ce7343b48e63 LIST: [PATCH v2 2/3] rust: configfs: introduce rust support for configfs 6efae1a9a226 rust: rnull: add module parameter support b6545e0eaf94 rust: rnull: enable configuration via `configfs` 6a3bc0dc31d0 rust: rnull: move driver to separate directory * modinfo sudo modinfo rnull_mod filename: /lib/modules/6.14.0-rc6-00015-g51d304103b7f/kernel/drivers/block/rnull/rnull_mod.ko author: Andreas Hindborg description: Rust implementation of the C null block driver license: GPL v2 name: rnull_mod intree: Y depends: vermagic: 6.14.0-rc6-00015-g51d304103b7f mod_unload modversions parm: nr_devices:Number of devices to register (u64) parm: bs:Block size (in bytes) (u32) parm: rotational:Set the rotational feature for the device (0 for false, 1 for true). Default: 0 (u8) parm: gb:Device capacity in MiB (u64) * Testing nr_devices parameter: sudo modprobe rnull_mod nr_devices=100 sudo ls /dev/rnullb* | wc -l 100 * Testing block size and capacity parameters: sudo rmmod rnull_mod sudo modprobe rnull_mod nr_devices=1 bs=512 gb=1024 sudo fdisk -l /dev/rnullb0 Disk /dev/rnullb0: 1 GiB, 1073741824 bytes, 2097152 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes * Testing block size with fio and blkalgn [1] (tool for validating driver block size): [1] blkalgn is an eBPF-based tool for tracing block operations that also reports block granularity and alignment histograms: https://github.com/dkruces/bcc/tree/blkalgn Install: https://github.com/dkruces/bcc/releases/latest/download/blkalgn-$(uname -m) \ --output /usr/sbin/blkalgn \ && sudo chmod +x /usr/sbin/blkalgn sudo modprobe rnull_mod nr_devices=1 bs=1024 gb=1024 sudo curl --location \ sudo blkalgn --disk=rnullb0 --ops=Write sudo fio --name=test --direct=1 --rw=write --bs=1024 --size=512k \ --filename=/dev/rnullb0 --loop=1000 I/O Granularity Histogram for Device rnullb0 (lbads: 10 - 1024 bytes) Total I/Os: 10748 Bytes : count distribution 1024 : 10748 |****************************************| I/O Alignment Histogram for Device rnullb0 Bytes : count distribution 0 -> 1 : 0 | | 2 -> 3 : 0 | | 4 -> 7 : 0 | | 8 -> 15 : 0 | | 16 -> 31 : 0 | | 32 -> 63 : 0 | | 64 -> 127 : 0 | | 128 -> 255 : 0 | | 256 -> 511 : 0 | | 512 -> 1023 : 0 | | 1024 -> 2047 : 10748 |****************************************| Tested-by: Daniel Gomez <da.gomez@xxxxxxxxxxx> Andreas, Petr, Miguel, Based on the discussion in v7, it seems that all these patches will go through the Rust tree. Is that correct? What would be missing from the module's side? I agree with Petr in that thread that if the changes are mostly limited to rust-module files, they can go through the module's tree. However, that is not the case yet. Daniel > --- > 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: 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 > modules: add rust modules files to MAINTAINERS > > MAINTAINERS | 2 + > rust/kernel/lib.rs | 1 + > rust/kernel/module_param.rs | 221 +++++++++++++++++++++++++++++++++++++++++++ > rust/kernel/str.rs | 200 +++++++++++++++++++++++++++++++++++++++ > rust/macros/helpers.rs | 25 +++++ > rust/macros/lib.rs | 31 ++++++ > rust/macros/module.rs | 191 +++++++++++++++++++++++++++++++++---- > samples/rust/rust_minimal.rs | 10 ++ > 8 files changed, 663 insertions(+), 18 deletions(-) > --- > base-commit: 379487e17ca406b47392e7ab6cf35d1c3bacb371 > change-id: 20241211-module-params-v3-ae7e5c8d8b5a > > Best regards, > -- > Andreas Hindborg <a.hindborg@xxxxxxxxxx> > >
