From: Andreas Hindborg <a.hindborg@xxxxxxxxxxx> This patch includes changes required for Rust kernel modules to utilize module parameters. This code implements read only support for integer types without `sysfs` support. This code is a reduced and updated version of code by Adam available in the original `rust` branch [1]. Link: https://github.com/Rust-for-Linux/linux/tree/bc22545f38d74473cfef3e9fd65432733435b79f [1] Cc: Adam Bratschi-Kaye <ark.email@xxxxxxxxx> Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxxx> --- Changes since v1 [2]: - 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: https://lore.kernel.org/rust-for-linux/20240705111455.142790-1-nmi@xxxxxxxxxxxx/ [2] --- rust/kernel/error.rs | 2 - rust/kernel/lib.rs | 1 + rust/kernel/module_param.rs | 339 +++++++++++++++++++++++++++++++++++ rust/macros/helpers.rs | 8 + rust/macros/lib.rs | 40 ++++- rust/macros/module.rs | 229 ++++++++++++++++++++--- samples/rust/rust_minimal.rs | 10 ++ scripts/Makefile.build | 2 +- 8 files changed, 593 insertions(+), 38 deletions(-) create mode 100644 rust/kernel/module_param.rs diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs index 145f5c397009..8532a09947d4 100644 --- a/rust/kernel/error.rs +++ b/rust/kernel/error.rs @@ -312,8 +312,6 @@ pub(crate) fn from_err_ptr<T>(ptr: *mut T) -> Result<*mut T> { /// }) /// } /// ``` -// TODO: Remove `dead_code` marker once an in-kernel client is available. -#[allow(dead_code)] pub(crate) fn from_result<T, F>(f: F) -> T where T: From<i16>, diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 274bdc1b0a82..2840237eb73b 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -38,6 +38,7 @@ pub mod ioctl; #[cfg(CONFIG_KUNIT)] pub mod kunit; +pub mod module_param; #[cfg(CONFIG_NET)] pub mod net; pub mod page; diff --git a/rust/kernel/module_param.rs b/rust/kernel/module_param.rs new file mode 100644 index 000000000000..9dfee0311d65 --- /dev/null +++ b/rust/kernel/module_param.rs @@ -0,0 +1,339 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Types for module parameters. +//! +//! C header: [`include/linux/moduleparam.h`](../../../include/linux/moduleparam.h) + +use crate::prelude::*; + +/// Types that can be used for module parameters. +/// +/// Note that displaying the type in `sysfs` will fail if +/// [`core::str::from_utf8`] (as implemented through the [`core::fmt::Display`] +/// trait) writes more than [`PAGE_SIZE`] bytes (including an additional null +/// terminator). +/// +/// [`PAGE_SIZE`]: `bindings::PAGE_SIZE` +pub trait ModuleParam: core::fmt::Display + core::marker::Sized { + /// The `ModuleParam` will be used by the kernel module through this type. + /// + /// This may differ from `Self` if, for example, `Self` needs to track + /// ownership without exposing it or allocate extra space for other possible + /// parameter values. This is required to support string parameters in the + /// future. + type Value: ?Sized; + + /// Parse a parameter argument into the parameter value. + /// + /// `Err(_)` should be returned when parsing of the argument fails. + /// + /// Parameters passed at boot time will be set before [`kmalloc`] is + /// available (even if the module is loaded at a later time). However, in + /// this case, the argument buffer will be valid for the entire lifetime of + /// the kernel. So implementations of this method which need to allocate + /// should first check that the allocator is available (with + /// [`crate::bindings::slab_is_available`]) and when it is not available + /// provide an alternative implementation which doesn't allocate. In cases + /// where the allocator is not available it is safe to save references to + /// `arg` in `Self`, but in other cases a copy should be made. + /// + /// [`kmalloc`]: ../../../include/linux/slab.h + fn try_from_param_arg(arg: &'static [u8]) -> Result<Self>; + + /// Get the current value of the parameter for use in the kernel module. + /// + /// This function should not be used directly. Instead use the wrapper + /// `read` which will be generated by [`macros::module`]. + fn value(&self) -> &Self::Value; +} + +/// Set the module parameter from a string. +/// +/// Used to set the parameter value at kernel initialization, when loading +/// the module or when set through `sysfs`. +/// +/// `param.arg` is a pointer to `*mut T` as set up by the [`module!`] +/// macro. +/// +/// See `struct kernel_param_ops.set`. +/// +/// # Safety +/// +/// If `val` is non-null then it must point to a valid null-terminated +/// string. The `arg` field of `param` must be an instance of `T`. +/// +/// # Invariants +/// +/// Currently, we only support read-only parameters that are not readable +/// from `sysfs`. Thus, this function is only called at kernel +/// initialization time, or at module load time, and we have exclusive +/// access to the parameter for the duration of the function. +/// +/// [`module!`]: macros::module +unsafe extern "C" fn set_param<T>( + val: *const core::ffi::c_char, + param: *const crate::bindings::kernel_param, +) -> core::ffi::c_int +where + T: ModuleParam, +{ + // NOTE: If we start supporting arguments without values, val _is_ allowed + // to be null here. + assert!(!val.is_null()); + + // SAFETY: By function safety requirement, val is non-null and + // null-terminated. By C API contract, `val` is live and valid for reads + // for the duration of this function. + let arg = unsafe { CStr::from_char_ptr(val).as_bytes() }; + + crate::error::from_result(|| { + let new_value = T::try_from_param_arg(arg)?; + + // SAFETY: `param` is guaranteed to be valid by C API contract + // and `arg` is guaranteed to point to an instance of `T`. + let old_value = unsafe { (*param).__bindgen_anon_1.arg as *mut T }; + + // SAFETY: `old_value` is valid for writes, as we have exclusive + // access. `old_value` is pointing to an initialized static, an + // so it is properly initialized. + unsafe { core::ptr::replace(old_value, new_value) }; + Ok(0) + }) +} + +/// Write a string representation of the current parameter value to `buf`. +/// +/// # Safety +/// +/// Must not be called. +/// +/// # Note +/// +/// This should not be called as we declare all parameters as read only. +#[allow(clippy::extra_unused_type_parameters)] +unsafe extern "C" fn get_param<T>( + _buf: *mut core::ffi::c_char, + _param: *const crate::bindings::kernel_param, +) -> core::ffi::c_int +where + T: ModuleParam, +{ + unreachable!("Parameters are not readable"); +} + +/// Drop the parameter. +/// +/// Called when unloading a module. +/// +/// # Safety +/// +/// The `arg` field of `param` must be an initialized instance of `Self`. +unsafe extern "C" fn free<T>(arg: *mut core::ffi::c_void) +where + T: ModuleParam, +{ + // SAFETY: By function safety requirement, `arg` is an initialized + // instance of `T`. By C API contract, `arg` will not be used after + // this function returns. + unsafe { core::ptr::drop_in_place(arg as *mut T) }; +} + +/// Trait for parsing integers. +/// +/// Strings beginning with `0x`, `0o`, or `0b` are parsed as hex, octal, or +/// binary respectively. Strings beginning with `0` otherwise are parsed as +/// octal. Anything else is parsed as decimal. A leading `+` or `-` is also +/// permitted. Any string parsed by [`kstrtol()`] or [`kstrtoul()`] will be +/// successfully parsed. +/// +/// [`kstrtol()`]: https://www.kernel.org/doc/html/latest/core-api/kernel-api.html#c.kstrtol +/// [`kstrtoul()`]: https://www.kernel.org/doc/html/latest/core-api/kernel-api.html#c.kstrtoul +trait ParseInt: Sized { + fn from_str_radix(src: &str, radix: u32) -> Result<Self, core::num::ParseIntError>; + + // NOTE: Required because `checked_neg` is not provided by any trait. + fn checked_neg(self) -> Option<Self>; + + fn from_str_unsigned(src: &str) -> Result<Self, core::num::ParseIntError> { + let (radix, digits) = if let Some(n) = src.strip_prefix("0x") { + (16, n) + } else if let Some(n) = src.strip_prefix("0X") { + (16, n) + } else if let Some(n) = src.strip_prefix("0o") { + (8, n) + } else if let Some(n) = src.strip_prefix("0O") { + (8, n) + } else if let Some(n) = src.strip_prefix("0b") { + (2, n) + } else if let Some(n) = src.strip_prefix("0B") { + (2, n) + } else if src.starts_with('0') { + (8, src) + } else { + (10, src) + }; + Self::from_str_radix(digits, radix) + } + + fn from_str(src: &str) -> Result<Self> { + match src.bytes().next() { + None => Err(EINVAL), + Some(b'-') => Self::from_str_unsigned(&src[1..]) + .map_err(|_| EINVAL)? + .checked_neg() + .ok_or(EINVAL), + Some(b'+') => Self::from_str_unsigned(&src[1..]).map_err(|_| EINVAL), + Some(_) => Self::from_str_unsigned(src).map_err(|_| EINVAL), + } + } +} + +macro_rules! impl_parse_int { + ($ty:ident) => { + impl ParseInt for $ty { + fn from_str_radix(src: &str, radix: u32) -> Result<Self, core::num::ParseIntError> { + $ty::from_str_radix(src, radix) + } + + fn checked_neg(self) -> Option<Self> { + self.checked_neg() + } + } + }; +} + +impl_parse_int!(i8); +impl_parse_int!(u8); +impl_parse_int!(i16); +impl_parse_int!(u16); +impl_parse_int!(i32); +impl_parse_int!(u32); +impl_parse_int!(i64); +impl_parse_int!(u64); +impl_parse_int!(isize); +impl_parse_int!(usize); + +macro_rules! impl_module_param { + ($ty:ident) => { + impl ModuleParam for $ty { + type Value = $ty; + + fn try_from_param_arg(arg: &'static [u8]) -> Result<Self> { + let utf8 = core::str::from_utf8(arg)?; + <$ty as crate::module_param::ParseInt>::from_str(utf8) + } + + #[inline(always)] + fn value(&self) -> &Self::Value { + self + } + } + }; +} + +#[doc(hidden)] +#[macro_export] +/// Generate a static [`kernel_param_ops`](../../../include/linux/moduleparam.h) struct. +/// +/// # Examples +/// +/// ```ignore +/// make_param_ops!( +/// /// Documentation for new param ops. +/// PARAM_OPS_MYTYPE, // Name for the static. +/// MyType // A type which implements [`ModuleParam`]. +/// ); +/// ``` +macro_rules! make_param_ops { + ($ops:ident, $ty:ty) => { + $crate::make_param_ops!( + #[doc=""] + $ops, + $ty + ); + }; + ($(#[$meta:meta])* $ops:ident, $ty:ty) => { + $(#[$meta])* + /// + /// Static [`kernel_param_ops`](../../../include/linux/moduleparam.h) + /// struct generated by [`make_param_ops`]. + pub static $ops: $crate::bindings::kernel_param_ops = $crate::bindings::kernel_param_ops { + flags: 0, + set: Some(set_param::<$ty>), + get: Some(get_param::<$ty>), + free: Some(free::<$ty>), + }; + }; +} + +impl_module_param!(i8); +impl_module_param!(u8); +impl_module_param!(i16); +impl_module_param!(u16); +impl_module_param!(i32); +impl_module_param!(u32); +impl_module_param!(i64); +impl_module_param!(u64); +impl_module_param!(isize); +impl_module_param!(usize); + +make_param_ops!( + /// Rust implementation of [`kernel_param_ops`](../../../include/linux/moduleparam.h) + /// for [`i8`]. + PARAM_OPS_I8, + i8 +); +make_param_ops!( + /// Rust implementation of [`kernel_param_ops`](../../../include/linux/moduleparam.h) + /// for [`u8`]. + PARAM_OPS_U8, + u8 +); +make_param_ops!( + /// Rust implementation of [`kernel_param_ops`](../../../include/linux/moduleparam.h) + /// for [`i16`]. + PARAM_OPS_I16, + i16 +); +make_param_ops!( + /// Rust implementation of [`kernel_param_ops`](../../../include/linux/moduleparam.h) + /// for [`u16`]. + PARAM_OPS_U16, + u16 +); +make_param_ops!( + /// Rust implementation of [`kernel_param_ops`](../../../include/linux/moduleparam.h) + /// for [`i32`]. + PARAM_OPS_I32, + i32 +); +make_param_ops!( + /// Rust implementation of [`kernel_param_ops`](../../../include/linux/moduleparam.h) + /// for [`u32`]. + PARAM_OPS_U32, + u32 +); +make_param_ops!( + /// Rust implementation of [`kernel_param_ops`](../../../include/linux/moduleparam.h) + /// for [`i64`]. + PARAM_OPS_I64, + i64 +); +make_param_ops!( + /// Rust implementation of [`kernel_param_ops`](../../../include/linux/moduleparam.h) + /// for [`u64`]. + PARAM_OPS_U64, + u64 +); +make_param_ops!( + /// Rust implementation of [`kernel_param_ops`](../../../include/linux/moduleparam.h) + /// for [`isize`]. + PARAM_OPS_ISIZE, + isize +); +make_param_ops!( + /// Rust implementation of [`kernel_param_ops`](../../../include/linux/moduleparam.h) + /// for [`usize`]. + PARAM_OPS_USIZE, + usize +); diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs index 563dcd2b7ace..49388907370d 100644 --- a/rust/macros/helpers.rs +++ b/rust/macros/helpers.rs @@ -107,6 +107,14 @@ pub(crate) struct Generics { pub(crate) ty_generics: Vec<TokenTree>, } +pub(crate) fn expect_string_field(it: &mut token_stream::IntoIter, expected_name: &str) -> String { + assert_eq!(expect_ident(it), expected_name); + assert_eq!(expect_punct(it), ':'); + let string = expect_string(it); + assert_eq!(expect_punct(it), ','); + string +} + /// Parses the given `TokenStream` into `Generics` and the rest. /// /// The generics are not present in the rest, but a where clause might remain. diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs index 159e75292970..1d7bc99ec5e0 100644 --- a/rust/macros/lib.rs +++ b/rust/macros/lib.rs @@ -20,6 +20,30 @@ /// The `type` argument should be a type which implements the [`Module`] /// trait. Also accepts various forms of kernel metadata. /// +/// The `params` field describe module parameters. Each entry has the form +/// +/// ```ignore +/// parameter_name: type { +/// default: default_value, +/// description: "Description", +/// } +/// ``` +/// +/// `type` may be one of +/// +/// - `i8` +/// - `u8` +/// - `i8` +/// - `u8` +/// - `i16` +/// - `u16` +/// - `i32` +/// - `u32` +/// - `i64` +/// - `u64` +/// - `isize` +/// - `usize` +/// /// C header: [`include/linux/moduleparam.h`](srctree/include/linux/moduleparam.h) /// /// [`Module`]: ../kernel/trait.Module.html @@ -36,21 +60,19 @@ /// description: "My very own kernel module!", /// license: "GPL", /// alias: ["alternate_module_name"], +/// params: { +/// my_parameter: i64 { +/// default: 1, +/// description: "This parameter has a default of 1", +/// }, +/// }, /// } /// /// struct MyModule; /// /// impl kernel::Module for MyModule { /// fn init() -> Result<Self> { -/// // If the parameter is writeable, then the kparam lock must be -/// // taken to read the parameter: -/// { -/// let lock = THIS_MODULE.kernel_param_lock(); -/// pr_info!("i32 param is: {}\n", writeable_i32.read(&lock)); -/// } -/// // If the parameter is read only, it can be read without locking -/// // the kernel parameters: -/// pr_info!("i32 param is: {}\n", my_i32.read()); +/// pr_info!("i32 param is: {}\n", module_parameters::my_parameter::read()); /// Ok(Self) /// } /// } diff --git a/rust/macros/module.rs b/rust/macros/module.rs index 411dc103d82e..2fa9ed8e78ff 100644 --- a/rust/macros/module.rs +++ b/rust/macros/module.rs @@ -26,6 +26,7 @@ struct ModInfoBuilder<'a> { module: &'a str, counter: usize, buffer: String, + param_buffer: String, } impl<'a> ModInfoBuilder<'a> { @@ -34,10 +35,11 @@ fn new(module: &'a str) -> Self { module, counter: 0, buffer: String::new(), + param_buffer: String::new(), } } - fn emit_base(&mut self, field: &str, content: &str, builtin: bool) { + fn emit_base(&mut self, field: &str, content: &str, builtin: bool, param: bool) { let string = if builtin { // Built-in modules prefix their modinfo strings by `module.`. format!( @@ -51,8 +53,14 @@ fn emit_base(&mut self, field: &str, content: &str, builtin: bool) { format!("{field}={content}\0", field = field, content = content) }; + let buffer = if param { + &mut self.param_buffer + } else { + &mut self.buffer + }; + write!( - &mut self.buffer, + buffer, " {cfg} #[doc(hidden)] @@ -75,20 +83,135 @@ fn emit_base(&mut self, field: &str, content: &str, builtin: bool) { self.counter += 1; } - fn emit_only_builtin(&mut self, field: &str, content: &str) { - self.emit_base(field, content, true) + fn emit_only_builtin(&mut self, field: &str, content: &str, param: bool) { + self.emit_base(field, content, true, param) } - fn emit_only_loadable(&mut self, field: &str, content: &str) { - self.emit_base(field, content, false) + fn emit_only_loadable(&mut self, field: &str, content: &str, param: bool) { + self.emit_base(field, content, false, param) } fn emit(&mut self, field: &str, content: &str) { - self.emit_only_builtin(field, content); - self.emit_only_loadable(field, content); + self.emit_internal(field, content, false); + } + + fn emit_internal(&mut self, field: &str, content: &str, param: bool) { + self.emit_only_builtin(field, content, param); + self.emit_only_loadable(field, content, param); + } + + fn emit_param(&mut self, field: &str, param: &str, content: &str) { + let content = format!("{param}:{content}", param = param, content = content); + self.emit_internal(field, &content, true); + } + + fn emit_params(&mut self, info: &ModuleInfo) { + if let Some(params) = &info.params { + for param in params { + let ops = param_ops_path(¶m.ptype); + + self.emit_param("parmtype", ¶m.name, ¶m.ptype); + self.emit_param("parm", ¶m.name, ¶m.description); + + write!( + self.param_buffer, + " + static mut __{name}_{param_name}_value: {param_type} = {param_default}; + + pub(crate) enum {param_name} {{}} + + impl {param_name} {{ + pub(crate) fn read<'a>() + -> &'a <{param_type} as ::kernel::module_param::ModuleParam>::Value {{ + // Note: when we enable r/w parameters, we need to lock here. + + // SAFETY: Parameters do not need to be locked because they are + // read only or sysfs is not enabled. + unsafe {{ + <{param_type} as ::kernel::module_param::ModuleParam>::value( + &__{name}_{param_name}_value + ) + }} + }} + }} + + /// Newtype to make `bindings::kernel_param` `Sync`. + #[repr(transparent)] + struct __{name}_{param_name}_RacyKernelParam(::kernel::bindings::kernel_param); + + // SAFETY: C kernel handles serializing access to this type. We + // never access from Rust module. + unsafe impl Sync for __{name}_{param_name}_RacyKernelParam {{ }} + + #[cfg(not(MODULE))] + const __{name}_{param_name}_name: *const ::core::ffi::c_char = + b\"{name}.{param_name}\\0\" as *const _ as *const ::core::ffi::c_char; + + #[cfg(MODULE)] + const __{name}_{param_name}_name: *const ::core::ffi::c_char = + b\"{param_name}\\0\" as *const _ as *const ::core::ffi::c_char; + + #[link_section = \"__param\"] + #[used] + static __{name}_{param_name}_struct: __{name}_{param_name}_RacyKernelParam = + __{name}_{param_name}_RacyKernelParam(::kernel::bindings::kernel_param {{ + name: __{name}_{param_name}_name, + // SAFETY: `__this_module` is constructed by the kernel at load time + // and will not be freed until the module is unloaded. + #[cfg(MODULE)] + mod_: unsafe {{ &::kernel::bindings::__this_module as *const _ as *mut _ }}, + #[cfg(not(MODULE))] + mod_: ::core::ptr::null_mut(), + ops: &{ops} as *const ::kernel::bindings::kernel_param_ops, + perm: 0, // Will not appear in sysfs + level: -1, + flags: 0, + __bindgen_anon_1: + ::kernel::bindings::kernel_param__bindgen_ty_1 {{ + // SAFETY: As this is evaluated in const context, it is + // safe to take a reference to a mut static. + arg: unsafe {{ + ::core::ptr::addr_of_mut!(__{name}_{param_name}_value) + }}.cast::<::core::ffi::c_void>(), + }}, + }}); + ", + name = info.name, + param_type = param.ptype, + param_default = param.default, + param_name = param.name, + ops = ops, + ) + .unwrap(); + } + } + } +} + +fn param_ops_path(param_type: &str) -> &'static str { + match param_type { + "i8" => "::kernel::module_param::PARAM_OPS_I8", + "u8" => "::kernel::module_param::PARAM_OPS_U8", + "i16" => "::kernel::module_param::PARAM_OPS_I16", + "u16" => "::kernel::module_param::PARAM_OPS_U16", + "i32" => "::kernel::module_param::PARAM_OPS_I32", + "u32" => "::kernel::module_param::PARAM_OPS_U32", + "i64" => "::kernel::module_param::PARAM_OPS_I64", + "u64" => "::kernel::module_param::PARAM_OPS_U64", + "isize" => "::kernel::module_param::PARAM_OPS_ISIZE", + "usize" => "::kernel::module_param::PARAM_OPS_USIZE", + t => panic!("Unsupported parameter type {}", t), } } +fn expect_param_default(param_it: &mut token_stream::IntoIter) -> String { + assert_eq!(expect_ident(param_it), "default"); + assert_eq!(expect_punct(param_it), ':'); + let default = try_literal(param_it).expect("Expected default param value"); + assert_eq!(expect_punct(param_it), ','); + default +} + #[derive(Debug, Default)] struct ModuleInfo { type_: String, @@ -98,6 +221,50 @@ struct ModuleInfo { description: Option<String>, alias: Option<Vec<String>>, firmware: Option<Vec<String>>, + params: Option<Vec<Parameter>>, +} + +#[derive(Debug)] +struct Parameter { + name: String, + ptype: String, + default: String, + description: String, +} + +fn expect_params(it: &mut token_stream::IntoIter) -> Vec<Parameter> { + let params = expect_group(it); + assert_eq!(params.delimiter(), Delimiter::Brace); + let mut it = params.stream().into_iter(); + let mut parsed = Vec::new(); + + loop { + let param_name = match it.next() { + Some(TokenTree::Ident(ident)) => ident.to_string(), + Some(_) => panic!("Expected Ident or end"), + None => break, + }; + + assert_eq!(expect_punct(&mut it), ':'); + let param_type = expect_ident(&mut it); + let group = expect_group(&mut it); + assert_eq!(group.delimiter(), Delimiter::Brace); + assert_eq!(expect_punct(&mut it), ','); + + let mut param_it = group.stream().into_iter(); + let param_default = expect_param_default(&mut param_it); + let param_description = expect_string_field(&mut param_it, "description"); + expect_end(&mut param_it); + + parsed.push(Parameter { + name: param_name, + ptype: param_type, + default: param_default, + description: param_description, + }) + } + + parsed } impl ModuleInfo { @@ -112,6 +279,7 @@ fn parse(it: &mut token_stream::IntoIter) -> Self { "license", "alias", "firmware", + "params", ]; const REQUIRED_KEYS: &[&str] = &["type", "name", "license"]; let mut seen_keys = Vec::new(); @@ -140,6 +308,7 @@ fn parse(it: &mut token_stream::IntoIter) -> Self { "license" => info.license = expect_string_ascii(it), "alias" => info.alias = Some(expect_string_array(it)), "firmware" => info.firmware = Some(expect_string_array(it)), + "params" => info.params = Some(expect_params(it)), _ => panic!( "Unknown key \"{}\". Valid keys are: {:?}.", key, EXPECTED_KEYS @@ -183,28 +352,30 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream { let info = ModuleInfo::parse(&mut it); let mut modinfo = ModInfoBuilder::new(info.name.as_ref()); - if let Some(author) = info.author { - modinfo.emit("author", &author); + if let Some(author) = &info.author { + modinfo.emit("author", author); } - if let Some(description) = info.description { - modinfo.emit("description", &description); + if let Some(description) = &info.description { + modinfo.emit("description", description); } modinfo.emit("license", &info.license); - if let Some(aliases) = info.alias { + if let Some(aliases) = &info.alias { for alias in aliases { - modinfo.emit("alias", &alias); + modinfo.emit("alias", alias); } } - if let Some(firmware) = info.firmware { + if let Some(firmware) = &info.firmware { for fw in firmware { - modinfo.emit("firmware", &fw); + modinfo.emit("firmware", fw); } } // Built-in modules also export the `file` modinfo string. let file = std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable"); - modinfo.emit_only_builtin("file", &file); + modinfo.emit_only_builtin("file", &file, false); + + modinfo.emit_params(&info); format!( " @@ -216,12 +387,14 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream { // 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 {{ - kernel::ThisModule::from_ptr(&kernel::bindings::__this_module as *const _ as *mut _) + static THIS_MODULE: ::kernel::ThisModule = unsafe {{ + ::kernel::ThisModule::from_ptr( + &::kernel::bindings::__this_module as *const _ as *mut _ + ) }}; #[cfg(not(MODULE))] - static THIS_MODULE: kernel::ThisModule = unsafe {{ - kernel::ThisModule::from_ptr(core::ptr::null_mut()) + static 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. @@ -276,7 +449,8 @@ mod __module_init {{ #[doc(hidden)] #[link_section = \"{initcall_section}\"] #[used] - pub static __{name}_initcall: extern \"C\" fn() -> core::ffi::c_int = __{name}_init; + pub static __{name}_initcall: extern \"C\" fn() + -> ::core::ffi::c_int = __{name}_init; #[cfg(not(MODULE))] #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)] @@ -291,7 +465,7 @@ mod __module_init {{ #[cfg(not(MODULE))] #[doc(hidden)] #[no_mangle] - pub extern \"C\" fn __{name}_init() -> core::ffi::c_int {{ + pub extern \"C\" fn __{name}_init() -> ::core::ffi::c_int {{ // SAFETY: This function is inaccessible to the outside due to the double // module wrapping it. It is called exactly once by the C side via its // placement above in the initcall section. @@ -314,8 +488,8 @@ mod __module_init {{ /// # Safety /// /// This function must only be called once. - unsafe fn __init() -> core::ffi::c_int {{ - match <{type_} as kernel::Module>::init(&super::super::THIS_MODULE) {{ + unsafe fn __init() -> ::core::ffi::c_int {{ + match <{type_} as ::kernel::Module>::init(&super::super::THIS_MODULE) {{ Ok(m) => {{ // SAFETY: No data race, since `__MOD` can only be accessed by this // module and there only `__init` and `__exit` access it. These @@ -346,14 +520,17 @@ unsafe fn __exit() {{ __MOD = None; }} }} - {modinfo} }} }} + mod module_parameters {{ + {params} + }} ", type_ = info.type_, name = info.name, modinfo = modinfo.buffer, + params = modinfo.param_buffer, initcall_section = ".initcall6.init" ) .parse() diff --git a/samples/rust/rust_minimal.rs b/samples/rust/rust_minimal.rs index 2a9eaab62d1c..d9bc2218d504 100644 --- a/samples/rust/rust_minimal.rs +++ b/samples/rust/rust_minimal.rs @@ -10,6 +10,12 @@ author: "Rust for Linux Contributors", description: "Rust minimal sample", license: "GPL", + params: { + test_parameter: i64 { + default: 1, + description: "This parameter has a default of 1", + }, + }, } struct RustMinimal { @@ -20,6 +26,10 @@ impl kernel::Module for RustMinimal { fn init(_module: &'static ThisModule) -> Result<Self> { pr_info!("Rust minimal sample (init)\n"); pr_info!("Am I built-in? {}\n", !cfg!(MODULE)); + pr_info!( + "My parameter: {}\n", + *module_parameters::test_parameter::read() + ); let mut numbers = Vec::new(); numbers.push(72, GFP_KERNEL)?; diff --git a/scripts/Makefile.build b/scripts/Makefile.build index efacca63c897..a65bd0233843 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -263,7 +263,7 @@ $(obj)/%.lst: $(obj)/%.c FORCE # Compile Rust sources (.rs) # --------------------------------------------------------------------------- -rust_allowed_features := new_uninit +rust_allowed_features := new_uninit,const_mut_refs # `--out-dir` is required to avoid temporaries being created by `rustc` in the # current working directory, which may be not accessible in the out-of-tree base-commit: 7c626ce4bae1ac14f60076d00eafe71af30450ba -- 2.46.0
