Generic `Allocator` support for Rust

Hi,

This patch series adds generic kernel allocator support for Rust, which so far
is limited to `kmalloc` allocations.

In order to abstain from (re-)adding unstable Rust features to the kernel, this
patch series does not extend the `Allocator` trait from Rust's `alloc` crate,
nor does it extend the `BoxExt` and `VecExt` extensions.

Instead, this series introduces a kernel specific `Allocator` trait, which is
implemented by the `Kmalloc`, `Vmalloc` and `KVmalloc` allocators, also
implemented in the context of this series.

As a consequence we need our own `Box` and `Vec` types, which are implemented by
this series as `KBox` and `KVec`.

With that, we can start using `KBox` and `KVec` throughout the tree and remove
the now obolete extensions `BoxExt` and `VecExt`.

For a final cleanup, this series removes the last minor dependencies to Rust's
`alloc` crate and removes it from the entire kernel build.

The series ensures not to break the `rusttest` make target by implementing the
`allocator_test` module providing a stub implementation for all kernel
`Allocator`s.

This patch series passes all KUnit tests, including the ones added by this
series. Additionally, the tests were run with `kmemleak` and `KASAN` enabled,
without any issues.

This series is also available in [1].

[1] https://gitlab.freedesktop.org/drm/nova/-/tree/topic/allo...

Danilo Krummrich (20):
  rust: alloc: add `Allocator` trait
  rust: alloc: separate `aligned_size` from `krealloc_aligned`
  rust: alloc: rename `KernelAllocator` to `Kmalloc`
  rust: alloc: implement `Allocator` for `Kmalloc`
  rust: alloc: add module `allocator_test`
  rust: alloc: remove `krealloc_aligned`
  rust: alloc: implement `Vmalloc` allocator
  rust: alloc: implement `KVmalloc` allocator
  rust: types: implement `Unique<T>`
  rust: alloc: implement `KBox`
  rust: treewide: switch to `KBox`
  rust: alloc: remove `BoxExt` extension
  rust: alloc: implement `KVec`
  rust: alloc: implement `IntoIterator` for `KVec`
  rust: alloc: implement `collect` for `IntoIter`
  rust: treewide: switch to `KVec`
  rust: alloc: remove `VecExt` extension
  rust: error: use `core::alloc::LayoutError`
  rust: str: test: replace `alloc::format`
  kbuild: rust: remove the `alloc` crate

 rust/Makefile                       |  44 +-
 rust/bindings/bindings_helper.h     |   1 +
 rust/exports.c                      |   1 -
 rust/kernel/alloc.rs                |  92 ++-
 rust/kernel/alloc/allocator.rs      | 177 +++++-
 rust/kernel/alloc/allocator_test.rs |  23 +
 rust/kernel/alloc/box_ext.rs        |  56 --
 rust/kernel/alloc/kbox.rs           | 333 +++++++++++
 rust/kernel/alloc/kvec.rs           | 861 ++++++++++++++++++++++++++++
 rust/kernel/alloc/vec_ext.rs        | 182 ------
 rust/kernel/error.rs                |   2 +-
 rust/kernel/init.rs                 |  72 +--
 rust/kernel/init/__internal.rs      |   2 +-
 rust/kernel/lib.rs                  |   1 -
 rust/kernel/prelude.rs              |   5 +-
 rust/kernel/str.rs                  |  78 ++-
 rust/kernel/sync/arc.rs             |  17 +-
 rust/kernel/sync/condvar.rs         |   5 +-
 rust/kernel/sync/lock/mutex.rs      |   3 +-
 rust/kernel/sync/lock/spinlock.rs   |   3 +-
 rust/kernel/sync/locked_by.rs       |   2 +-
 rust/kernel/types.rs                | 186 +++++-
 rust/kernel/workqueue.rs            |  22 +-
 samples/rust/rust_minimal.rs        |   4 +-
 scripts/Makefile.build              |   7 +-
 25 files changed, 1769 insertions(+), 410 deletions(-)
 create mode 100644 rust/kernel/alloc/allocator_test.rs
 delete mode 100644 rust/kernel/alloc/box_ext.rs
 create mode 100644 rust/kernel/alloc/kbox.rs
 create mode 100644 rust/kernel/alloc/kvec.rs
 delete mode 100644 rust/kernel/alloc/vec_ext.rs


base-commit: 1613e604df0cd359cf2a7fbd9be7a0bcfacfabd0
-- 
2.45.2