linux/rust/kernel/allocator.rs
Wedson Almeida Filho 247b365dc8 rust: add kernel crate
The `kernel` crate currently includes all the abstractions that wrap
kernel features written in C.

These abstractions call the C side of the kernel via the generated
bindings with the `bindgen` tool. Modules developed in Rust should
never call the bindings themselves.

In the future, as the abstractions grow in number, we may need
to split this crate into several, possibly following a similar
subdivision in subsystems as the kernel itself and/or moving
the code to the actual subsystems.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Geoffrey Thomas <geofft@ldpreload.com>
Signed-off-by: Geoffrey Thomas <geofft@ldpreload.com>
Co-developed-by: Finn Behrens <me@kloenk.de>
Signed-off-by: Finn Behrens <me@kloenk.de>
Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com>
Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Boris-Chengbiao Zhou <bobo1239@web.de>
Signed-off-by: Boris-Chengbiao Zhou <bobo1239@web.de>
Co-developed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Co-developed-by: Fox Chen <foxhlchen@gmail.com>
Signed-off-by: Fox Chen <foxhlchen@gmail.com>
Co-developed-by: Viktor Garske <viktor@v-gar.de>
Signed-off-by: Viktor Garske <viktor@v-gar.de>
Co-developed-by: Dariusz Sosnowski <dsosnowski@dsosnowski.pl>
Signed-off-by: Dariusz Sosnowski <dsosnowski@dsosnowski.pl>
Co-developed-by: Léo Lanteri Thauvin <leseulartichaut@gmail.com>
Signed-off-by: Léo Lanteri Thauvin <leseulartichaut@gmail.com>
Co-developed-by: Niklas Mohrin <dev@niklasmohrin.de>
Signed-off-by: Niklas Mohrin <dev@niklasmohrin.de>
Co-developed-by: Milan Landaverde <milan@mdaverde.com>
Signed-off-by: Milan Landaverde <milan@mdaverde.com>
Co-developed-by: Morgan Bartlett <mjmouse9999@gmail.com>
Signed-off-by: Morgan Bartlett <mjmouse9999@gmail.com>
Co-developed-by: Maciej Falkowski <m.falkowski@samsung.com>
Signed-off-by: Maciej Falkowski <m.falkowski@samsung.com>
Co-developed-by: Nándor István Krácser <bonifaido@gmail.com>
Signed-off-by: Nándor István Krácser <bonifaido@gmail.com>
Co-developed-by: David Gow <davidgow@google.com>
Signed-off-by: David Gow <davidgow@google.com>
Co-developed-by: John Baublitz <john.m.baublitz@gmail.com>
Signed-off-by: John Baublitz <john.m.baublitz@gmail.com>
Co-developed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Signed-off-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28 08:58:24 +02:00

65 lines
1.8 KiB
Rust

// SPDX-License-Identifier: GPL-2.0
//! Allocator support.
use core::alloc::{GlobalAlloc, Layout};
use core::ptr;
use crate::bindings;
struct KernelAllocator;
unsafe impl GlobalAlloc for KernelAllocator {
unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
// `krealloc()` is used instead of `kmalloc()` because the latter is
// an inline function and cannot be bound to as a result.
unsafe { bindings::krealloc(ptr::null(), layout.size(), bindings::GFP_KERNEL) as *mut u8 }
}
unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
unsafe {
bindings::kfree(ptr as *const core::ffi::c_void);
}
}
}
#[global_allocator]
static ALLOCATOR: KernelAllocator = KernelAllocator;
// `rustc` only generates these for some crate types. Even then, we would need
// to extract the object file that has them from the archive. For the moment,
// let's generate them ourselves instead.
//
// Note that `#[no_mangle]` implies exported too, nowadays.
#[no_mangle]
fn __rust_alloc(size: usize, _align: usize) -> *mut u8 {
unsafe { bindings::krealloc(core::ptr::null(), size, bindings::GFP_KERNEL) as *mut u8 }
}
#[no_mangle]
fn __rust_dealloc(ptr: *mut u8, _size: usize, _align: usize) {
unsafe { bindings::kfree(ptr as *const core::ffi::c_void) };
}
#[no_mangle]
fn __rust_realloc(ptr: *mut u8, _old_size: usize, _align: usize, new_size: usize) -> *mut u8 {
unsafe {
bindings::krealloc(
ptr as *const core::ffi::c_void,
new_size,
bindings::GFP_KERNEL,
) as *mut u8
}
}
#[no_mangle]
fn __rust_alloc_zeroed(size: usize, _align: usize) -> *mut u8 {
unsafe {
bindings::krealloc(
core::ptr::null(),
size,
bindings::GFP_KERNEL | bindings::__GFP_ZERO,
) as *mut u8
}
}