[PATCH 10/10] rust: kernel: remove usage of `allocator_api` unstable feature

Wedson Almeida Filho
2024-03-25T19:55:48Z

From: Wedson Almeida Filho <walmeida@microsoft.com>

With the adoption of `BoxExt` and `VecExt`, we don't need the functions
provided by this feature (namely the methods prefixed with `try_` and
different allocator per collection instance).

We do need `AllocError`, but we define our own as it is a trivial empty
struct.

Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
---
rust/kernel/alloc.rs | 3 +++
rust/kernel/alloc/boxext.rs | 3 +--
rust/kernel/alloc/vecext.rs | 4 ++--
rust/kernel/error.rs | 13 ++-----------
rust/kernel/init.rs | 3 +--
rust/kernel/lib.rs | 1 -
rust/kernel/str.rs | 3 +--
rust/kernel/sync/arc.rs | 4 ++--
rust/kernel/workqueue.rs | 3 +--
9 files changed, 13 insertions(+), 24 deletions(-)

diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs
index 5712c81b1308..f17f48130f13 100644
--- a/rust/kernel/alloc.rs
+++ b/rust/kernel/alloc.rs
@@ -8,6 +8,9 @@
pub mod boxext;
pub mod vecext;

+/// Indicates an allocation error.
+pub struct AllocError;
+
/// Flags to be used when allocating memory.
///
/// They can be combined with the operators `|`, `&`, and `!`.
diff --git a/rust/kernel/alloc/boxext.rs b/rust/kernel/alloc/boxext.rs
index 26a918df7acf..3cdda0f635a3 100644
--- a/rust/kernel/alloc/boxext.rs
+++ b/rust/kernel/alloc/boxext.rs
@@ -2,9 +2,8 @@

//! Extensions to [`Box`] for fallible allocations.

-use super::Flags;
+use super::{AllocError, Flags};
use alloc::boxed::Box;
-use core::alloc::AllocError;
use core::mem::MaybeUninit;
use core::result::Result;

diff --git a/rust/kernel/alloc/vecext.rs b/rust/kernel/alloc/vecext.rs
index 1d4d51b45a49..85ca6a6db6de 100644
--- a/rust/kernel/alloc/vecext.rs
+++ b/rust/kernel/alloc/vecext.rs
@@ -2,8 +2,8 @@

//! Extensions to [`Vec`] for fallible allocations.

-use super::Flags;
-use alloc::{alloc::AllocError, vec::Vec};
+use super::{AllocError, Flags};
+use alloc::vec::Vec;
use core::{mem::ManuallyDrop, result::Result};

/// Extensions to [`Vec`].
diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index 4786d3ee1e92..fc986bc24c6d 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -4,12 +4,9 @@
//!
//! C header: [`include/uapi/asm-generic/errno-base.h`](srctree/include/uapi/asm-generic/errno-base.h)

-use crate::str::CStr;
+use crate::{alloc::AllocError, str::CStr};

-use alloc::{
- alloc::{AllocError, LayoutError},
- collections::TryReserveError,
-};
+use alloc::alloc::LayoutError;

use core::convert::From;
use core::fmt;
@@ -192,12 +189,6 @@ fn from(_: Utf8Error) -> Error {
}
}

-impl From<TryReserveError> for Error {
- fn from(_: TryReserveError) -> Error {
- code::ENOMEM
- }
-}
-
impl From<LayoutError> for Error {
fn from(_: LayoutError) -> Error {
code::ENOMEM
diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs
index 1a8b0464db0c..1f7a6b5892ac 100644
--- a/rust/kernel/init.rs
+++ b/rust/kernel/init.rs
@@ -211,14 +211,13 @@
//! [`pin_init!`]: crate::pin_init!

use crate::{
- alloc::{boxext::BoxExt, Flags},
+ alloc::{boxext::BoxExt, AllocError, Flags},
error::{self, Error},
sync::UniqueArc,
types::{Opaque, ScopeGuard},
};
use alloc::boxed::Box;
use core::{
- alloc::AllocError,
cell::UnsafeCell,
convert::Infallible,
marker::PhantomData,
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 51f30e55bd00..5c641233e26d 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -12,7 +12,6 @@
//! do so first instead of bypassing this crate.

#![no_std]
-#![feature(allocator_api)]
#![feature(coerce_unsized)]
#![feature(dispatch_from_dyn)]
#![feature(new_uninit)]
diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
index 34dbc85b5220..5206b18f882b 100644
--- a/rust/kernel/str.rs
+++ b/rust/kernel/str.rs
@@ -2,8 +2,7 @@

//! String representations.

-use crate::alloc::{flags::*, vecext::VecExt};
-use alloc::alloc::AllocError;
+use crate::alloc::{flags::*, vecext::VecExt, AllocError};
use alloc::vec::Vec;
use core::fmt::{self, Write};
use core::ops::{self, Deref, Index};
diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index af539c5eb4bc..8db25f73b37f 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -16,7 +16,7 @@
//! [`Arc`]: https://doc.rust-lang.org/std/sync/struct.Arc.html

use crate::{
- alloc::{boxext::BoxExt, Flags},
+ alloc::{boxext::BoxExt, AllocError, Flags},
bindings,
error::{self, Error},
init::{self, InPlaceInit, Init, PinInit},
@@ -25,7 +25,7 @@
};
use alloc::boxed::Box;
use core::{
- alloc::{AllocError, Layout},
+ alloc::Layout,
fmt,
marker::{PhantomData, Unsize},
mem::{ManuallyDrop, MaybeUninit},
diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
index 09a0f158ff1b..50837e56efc7 100644
--- a/rust/kernel/workqueue.rs
+++ b/rust/kernel/workqueue.rs
@@ -132,9 +132,8 @@
//!
//! C header: [`include/linux/workqueue.h`](srctree/include/linux/workqueue.h)

-use crate::alloc::Flags;
+use crate::alloc::{AllocError, Flags};
use crate::{bindings, prelude::*, sync::Arc, sync::LockClassKey, types::Opaque};
-use alloc::alloc::AllocError;
use alloc::boxed::Box;
use core::marker::PhantomData;
use core::pin::Pin;
--
2.34.1