linux/rust/kernel/lib.rs
Wedson Almeida Filho f75cb6fce4 rust: sync: allow coercion from Arc<T> to Arc<U>
The coercion is only allowed if `U` is a compatible dynamically-sized
type (DST). For example, if we have some type `X` that implements trait
`Y`, then this allows `Arc<X>` to be coerced into `Arc<dyn Y>`.

Suggested-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-01-16 22:20:24 +01:00

92 lines
2.6 KiB
Rust

// SPDX-License-Identifier: GPL-2.0
//! The `kernel` crate.
//!
//! This crate contains the kernel APIs that have been ported or wrapped for
//! usage by Rust code in the kernel and is shared by all of them.
//!
//! In other words, all the rest of the Rust code in the kernel (e.g. kernel
//! modules written in Rust) depends on [`core`], [`alloc`] and this crate.
//!
//! If you need a kernel C API that is not ported or wrapped yet here, then
//! do so first instead of bypassing this crate.
#![no_std]
#![feature(allocator_api)]
#![feature(coerce_unsized)]
#![feature(core_ffi_c)]
#![feature(receiver_trait)]
#![feature(unsize)]
// Ensure conditional compilation based on the kernel configuration works;
// otherwise we may silently break things like initcall handling.
#[cfg(not(CONFIG_RUST))]
compile_error!("Missing kernel configuration for conditional compilation");
#[cfg(not(test))]
#[cfg(not(testlib))]
mod allocator;
mod build_assert;
pub mod error;
pub mod prelude;
pub mod print;
mod static_assert;
#[doc(hidden)]
pub mod std_vendor;
pub mod str;
pub mod sync;
pub mod types;
#[doc(hidden)]
pub use bindings;
pub use macros;
#[doc(hidden)]
pub use build_error::build_error;
/// Prefix to appear before log messages printed from within the `kernel` crate.
const __LOG_PREFIX: &[u8] = b"rust_kernel\0";
/// The top level entrypoint to implementing a kernel module.
///
/// For any teardown or cleanup operations, your type may implement [`Drop`].
pub trait Module: Sized + Sync {
/// Called at module initialization time.
///
/// Use this method to perform whatever setup or registration your module
/// should do.
///
/// Equivalent to the `module_init` macro in the C API.
fn init(module: &'static ThisModule) -> error::Result<Self>;
}
/// Equivalent to `THIS_MODULE` in the C API.
///
/// C header: `include/linux/export.h`
pub struct ThisModule(*mut bindings::module);
// SAFETY: `THIS_MODULE` may be used from all threads within a module.
unsafe impl Sync for ThisModule {}
impl ThisModule {
/// Creates a [`ThisModule`] given the `THIS_MODULE` pointer.
///
/// # Safety
///
/// The pointer must be equal to the right `THIS_MODULE`.
pub const unsafe fn from_ptr(ptr: *mut bindings::module) -> ThisModule {
ThisModule(ptr)
}
}
#[cfg(not(any(testlib, test)))]
#[panic_handler]
fn panic(info: &core::panic::PanicInfo<'_>) -> ! {
pr_emerg!("{}\n", info);
// SAFETY: FFI call.
unsafe { bindings::BUG() };
// Bindgen currently does not recognize `__noreturn` so `BUG` returns `()`
// instead of `!`. See <https://github.com/rust-lang/rust-bindgen/issues/2094>.
loop {}
}