mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-05 10:29:37 +00:00
![Benno Lossin](/assets/img/avatar_default.png)
The `PinnedDrop` trait that facilitates destruction of pinned types. It has to be implemented via the `#[pinned_drop]` macro, since the `drop` function should not be called by normal code, only by other destructors. It also only works on structs that are annotated with `#[pin_data(PinnedDrop)]`. Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230408122429.1103522-10-y86-dev@protonmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
248 lines
7 KiB
Rust
248 lines
7 KiB
Rust
// SPDX-License-Identifier: GPL-2.0
|
|
|
|
//! Crate for all kernel procedural macros.
|
|
|
|
#[macro_use]
|
|
mod quote;
|
|
mod concat_idents;
|
|
mod helpers;
|
|
mod module;
|
|
mod pin_data;
|
|
mod pinned_drop;
|
|
mod vtable;
|
|
|
|
use proc_macro::TokenStream;
|
|
|
|
/// Declares a kernel module.
|
|
///
|
|
/// The `type` argument should be a type which implements the [`Module`]
|
|
/// trait. Also accepts various forms of kernel metadata.
|
|
///
|
|
/// C header: [`include/linux/moduleparam.h`](../../../include/linux/moduleparam.h)
|
|
///
|
|
/// [`Module`]: ../kernel/trait.Module.html
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```ignore
|
|
/// use kernel::prelude::*;
|
|
///
|
|
/// module!{
|
|
/// type: MyModule,
|
|
/// name: "my_kernel_module",
|
|
/// author: "Rust for Linux Contributors",
|
|
/// description: "My very own kernel module!",
|
|
/// license: "GPL",
|
|
/// params: {
|
|
/// my_i32: i32 {
|
|
/// default: 42,
|
|
/// permissions: 0o000,
|
|
/// description: "Example of i32",
|
|
/// },
|
|
/// writeable_i32: i32 {
|
|
/// default: 42,
|
|
/// permissions: 0o644,
|
|
/// description: "Example of i32",
|
|
/// },
|
|
/// },
|
|
/// }
|
|
///
|
|
/// 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());
|
|
/// Ok(Self)
|
|
/// }
|
|
/// }
|
|
/// ```
|
|
///
|
|
/// # Supported argument types
|
|
/// - `type`: type which implements the [`Module`] trait (required).
|
|
/// - `name`: byte array of the name of the kernel module (required).
|
|
/// - `author`: byte array of the author of the kernel module.
|
|
/// - `description`: byte array of the description of the kernel module.
|
|
/// - `license`: byte array of the license of the kernel module (required).
|
|
/// - `alias`: byte array of alias name of the kernel module.
|
|
#[proc_macro]
|
|
pub fn module(ts: TokenStream) -> TokenStream {
|
|
module::module(ts)
|
|
}
|
|
|
|
/// Declares or implements a vtable trait.
|
|
///
|
|
/// Linux's use of pure vtables is very close to Rust traits, but they differ
|
|
/// in how unimplemented functions are represented. In Rust, traits can provide
|
|
/// default implementation for all non-required methods (and the default
|
|
/// implementation could just return `Error::EINVAL`); Linux typically use C
|
|
/// `NULL` pointers to represent these functions.
|
|
///
|
|
/// This attribute is intended to close the gap. Traits can be declared and
|
|
/// implemented with the `#[vtable]` attribute, and a `HAS_*` associated constant
|
|
/// will be generated for each method in the trait, indicating if the implementor
|
|
/// has overridden a method.
|
|
///
|
|
/// This attribute is not needed if all methods are required.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```ignore
|
|
/// use kernel::prelude::*;
|
|
///
|
|
/// // Declares a `#[vtable]` trait
|
|
/// #[vtable]
|
|
/// pub trait Operations: Send + Sync + Sized {
|
|
/// fn foo(&self) -> Result<()> {
|
|
/// Err(EINVAL)
|
|
/// }
|
|
///
|
|
/// fn bar(&self) -> Result<()> {
|
|
/// Err(EINVAL)
|
|
/// }
|
|
/// }
|
|
///
|
|
/// struct Foo;
|
|
///
|
|
/// // Implements the `#[vtable]` trait
|
|
/// #[vtable]
|
|
/// impl Operations for Foo {
|
|
/// fn foo(&self) -> Result<()> {
|
|
/// # Err(EINVAL)
|
|
/// // ...
|
|
/// }
|
|
/// }
|
|
///
|
|
/// assert_eq!(<Foo as Operations>::HAS_FOO, true);
|
|
/// assert_eq!(<Foo as Operations>::HAS_BAR, false);
|
|
/// ```
|
|
#[proc_macro_attribute]
|
|
pub fn vtable(attr: TokenStream, ts: TokenStream) -> TokenStream {
|
|
vtable::vtable(attr, ts)
|
|
}
|
|
|
|
/// Concatenate two identifiers.
|
|
///
|
|
/// This is useful in macros that need to declare or reference items with names
|
|
/// starting with a fixed prefix and ending in a user specified name. The resulting
|
|
/// identifier has the span of the second argument.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```ignore
|
|
/// use kernel::macro::concat_idents;
|
|
///
|
|
/// macro_rules! pub_no_prefix {
|
|
/// ($prefix:ident, $($newname:ident),+) => {
|
|
/// $(pub(crate) const $newname: u32 = kernel::macros::concat_idents!($prefix, $newname);)+
|
|
/// };
|
|
/// }
|
|
///
|
|
/// pub_no_prefix!(
|
|
/// binder_driver_return_protocol_,
|
|
/// BR_OK,
|
|
/// BR_ERROR,
|
|
/// BR_TRANSACTION,
|
|
/// BR_REPLY,
|
|
/// BR_DEAD_REPLY,
|
|
/// BR_TRANSACTION_COMPLETE,
|
|
/// BR_INCREFS,
|
|
/// BR_ACQUIRE,
|
|
/// BR_RELEASE,
|
|
/// BR_DECREFS,
|
|
/// BR_NOOP,
|
|
/// BR_SPAWN_LOOPER,
|
|
/// BR_DEAD_BINDER,
|
|
/// BR_CLEAR_DEATH_NOTIFICATION_DONE,
|
|
/// BR_FAILED_REPLY
|
|
/// );
|
|
///
|
|
/// assert_eq!(BR_OK, binder_driver_return_protocol_BR_OK);
|
|
/// ```
|
|
#[proc_macro]
|
|
pub fn concat_idents(ts: TokenStream) -> TokenStream {
|
|
concat_idents::concat_idents(ts)
|
|
}
|
|
|
|
/// Used to specify the pinning information of the fields of a struct.
|
|
///
|
|
/// This is somewhat similar in purpose as
|
|
/// [pin-project-lite](https://crates.io/crates/pin-project-lite).
|
|
/// Place this macro on a struct definition and then `#[pin]` in front of the attributes of each
|
|
/// field you want to structurally pin.
|
|
///
|
|
/// This macro enables the use of the [`pin_init!`] macro. When pin-initializing a `struct`,
|
|
/// then `#[pin]` directs the type of initializer that is required.
|
|
///
|
|
/// If your `struct` implements `Drop`, then you need to add `PinnedDrop` as arguments to this
|
|
/// macro, and change your `Drop` implementation to `PinnedDrop` annotated with
|
|
/// `#[`[`macro@pinned_drop`]`]`, since dropping pinned values requires extra care.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```rust,ignore
|
|
/// #[pin_data]
|
|
/// struct DriverData {
|
|
/// #[pin]
|
|
/// queue: Mutex<Vec<Command>>,
|
|
/// buf: Box<[u8; 1024 * 1024]>,
|
|
/// }
|
|
/// ```
|
|
///
|
|
/// ```rust,ignore
|
|
/// #[pin_data(PinnedDrop)]
|
|
/// struct DriverData {
|
|
/// #[pin]
|
|
/// queue: Mutex<Vec<Command>>,
|
|
/// buf: Box<[u8; 1024 * 1024]>,
|
|
/// raw_info: *mut Info,
|
|
/// }
|
|
///
|
|
/// #[pinned_drop]
|
|
/// impl PinnedDrop for DriverData {
|
|
/// fn drop(self: Pin<&mut Self>) {
|
|
/// unsafe { bindings::destroy_info(self.raw_info) };
|
|
/// }
|
|
/// }
|
|
/// ```
|
|
///
|
|
/// [`pin_init!`]: ../kernel/macro.pin_init.html
|
|
// ^ cannot use direct link, since `kernel` is not a dependency of `macros`.
|
|
#[proc_macro_attribute]
|
|
pub fn pin_data(inner: TokenStream, item: TokenStream) -> TokenStream {
|
|
pin_data::pin_data(inner, item)
|
|
}
|
|
|
|
/// Used to implement `PinnedDrop` safely.
|
|
///
|
|
/// Only works on structs that are annotated via `#[`[`macro@pin_data`]`]`.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```rust,ignore
|
|
/// #[pin_data(PinnedDrop)]
|
|
/// struct DriverData {
|
|
/// #[pin]
|
|
/// queue: Mutex<Vec<Command>>,
|
|
/// buf: Box<[u8; 1024 * 1024]>,
|
|
/// raw_info: *mut Info,
|
|
/// }
|
|
///
|
|
/// #[pinned_drop]
|
|
/// impl PinnedDrop for DriverData {
|
|
/// fn drop(self: Pin<&mut Self>) {
|
|
/// unsafe { bindings::destroy_info(self.raw_info) };
|
|
/// }
|
|
/// }
|
|
/// ```
|
|
#[proc_macro_attribute]
|
|
pub fn pinned_drop(args: TokenStream, input: TokenStream) -> TokenStream {
|
|
pinned_drop::pinned_drop(args, input)
|
|
}
|