We (Asahi Linux) noticed that this doesn't support unsized types, which is a regression from the alloc Box. drm/asahi uses boxed trait objects to generalize across certain object types like render commands, so this breaks the driver. Is there a plan to add this back in? AIUI this would need the coerce_unsized unstable feature, but is there any other blocker? On 10/5/24 12:41 AM, Danilo Krummrich wrote: > 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 kernel `Box<T, A>` and `Vec<T, A>` types. > Additionally, this series adds the following type aliases: > > ``` > pub type KBox<T> = Box<T, Kmalloc>; > pub type VBox<T> = Box<T, Vmalloc>; > pub type KVBox<T> = Box<T, KVmalloc>; > > > pub type KVec<T> = Vec<T, Kmalloc>; > pub type VVec<T> = Vec<T, Vmalloc>; > pub type KVVec<T> = Vec<T, KVmalloc>; > ``` > > With that, we can start using the kernel `Box` and `Vec` types 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 based on [1], which hit -mm/mm-stable, and is also available > in [2]. > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/dakr/linux.git/log/?h=mm/krealloc > [2] https://git.kernel.org/pub/scm/linux/kernel/git/dakr/linux.git/log/?h=rust/mm > > Changes in v9: > - rebase onto rust-next (lint series) > - `Vec`: > - add missing invariant comments > - fix missing `#![feature(inline_const)]` > - add note for `kvec!` that GFP_KERNEL is used for allocation > - `ArrayLayout`: fix missing import for `size_of::<T>` > - `Box`: fix missing safety comment > > Changes in v8: > - rebase onto rust-next (v6.12-rc1), including the -mm dependencies from [1] > - introduce `ArrayLayout` and rework the `Allocator` trait to take an > `old_layout` argument > - split up "rust: alloc: implement `Allocator` for `Kmalloc`" in three > separate patches (introduce `ReallocFunc`, make allocator module public and > implement `Kmalloc`) > - wrap `impl_slice_eq!` pattern in `$()*` > - couple of style changes suggested by Benno and Gary > > Changes in v7: > - rebase onto rust-next resolving recent conflicts (93dc3be19450447a3a7090bd1dfb9f3daac3e8d2) > - documentation / safety comment changes suggested by Benno and Boqun > - rename `ptr` to `current` in `IntoIter::next` (Alice) > - remove unnecessary braces in `kvec!` (Benno) > - add `debug_assert!` in `Vec::set_len` (Benno) > - remove unused args in `impl_slice_eq!` (Benno) > - simplify `if` statement in `Cmalloc::realloc` (Benno) > > Changes in v6: > - rebase onto rust-dev > - keep compiler annotations for {k,v,kv}realloc() > - documentation changes suggested by Alice, Benno > - remove `Box::into_pin` > - fix typo in `Send` and `Sync` for `Box` and `Vec` > - `kvec!` changes suggested by Alice > - free `src` after copy in `Cmalloc` > - handle `n == 0` in `Vec::extend_with` > > Changes in v5: > - (safety) comment / documentation fixes suggested by Alice, Benno and Gary > - remove `Unique<T>` and implement `Send` and `Sync` for `Box` and `Vec` > - use `KMALLOC_MAX_SIZE` for `KVmalloc` test and add a `Kmalloc` test that > expects to fail for `KMALLOC_MAX_SIZE` > - create use constants `KREALLOC`, `VREALLOC` and `KVREALLOC` for > `ReallocFuncs` > - drop `Box::drop_contents` for now, will add it again, once I actually rebase > on the original patch that introduces it > - improve usage of `size_of_val` in `Box` > - move `InPlaceInit` and `ForeignOwnable` impls into kbox.rs > - fix missing `Box` conversions in rnull.rs > - reworked `Cmalloc` to keep track of the size of memory allocations itself > - remove `GlobalAlloc` together with the `alloc` crate to avoid a linker error > - remove `alloc` from scripts/generate_rust_analyzer.py > > Changes in v4: > - (safety) comment fixes suggested by Alice and Boqun > - remove `Box::from_raw_alloc` and `Box::into_raw_alloc`, we don't need them > - in `Box::drop` call `size_of_val` before `drop_in_place` > - implement ForeignOwnable for Pin<Box<T>> as suggested by Alice > - in `Vec::extend_with`, iterate over `n` instead of `spare.len()` > - for `Vmalloc` and `KVmalloc` fail allocation for alignments larger than > PAGE_SIZE for now (will add support for larger alignments in a separate > series) > - implement `Cmalloc` in `allocator_test` and type alias all kernel allocator > types to it, such that we can use the kernel's `Box` and `Vec` types in > userspace tests (rusttest) > - this makes patch "rust: str: test: replace `alloc::format`" rather trivial > > Changes in v3: > - Box: > - minor documentation fixes > - removed unnecessary imports in doc tests > - dropeed `self` argument from some remaining `Box` methods > - implement `InPlaceInit` for Box<T, A> rather than specifically for `KBox<T>` > - Vec: > - minor documentation fixes > - removed useless `Vec::allocator` method > - in `Vec::extend_with` use `Vec::spare_capacity_mut` instead of raw pointer operations > - added a few missing safety comments > - pass GFP flags to `Vec::collect` > - fixed a rustdoc warning in alloc.rs > - fixed the allocator_test module to implement the `Allocator` trait correctly > - rebased to rust-next > > Changes in v2: > - preserve `impl GlobalAlloc for Kmalloc` and remove it at the end (Benno) > - remove `&self` parameter from all `Allocator` functions (Benno) > - various documentation fixes for `Allocator` (Benno) > - use `NonNull<u8>` for `Allocator::free` and `Option<NonNull<u8>>` for > `Allocator::realloc` (Benno) > - fix leak of `IntoIter` in `Vec::collect` (Boqun) > - always realloc (try to shrink) in `Vec::collect`, it's up the the > `Allocator` to provide a heuristic whether it makes sense to actually shrink > - rename `KBox<T, A>` -> `Box<T, A>` and `KVec<T, A>` -> `Vec<T, A>` and > provide type aliases `KBox<T>`, `VBox<T>`, `KVBox<T>`, etc. > - This allows for much cleaner code and, in combination with removing > `&self` parameters from `Allocator`s, gets us rid of the need for > `Box::new` and `Box::new_alloc` and all other "_alloc" postfixed > functions. > - Before: `KBox::new_alloc(foo, Vmalloc)?` > - After: `VBox::new(foo)?`, which resolves to > `Box::<Foo, Vmalloc>::new(foo)?; > > Benno Lossin (1): > rust: alloc: introduce `ArrayLayout` > > Danilo Krummrich (28): > rust: alloc: add `Allocator` trait > rust: alloc: separate `aligned_size` from `krealloc_aligned` > rust: alloc: rename `KernelAllocator` to `Kmalloc` > rust: alloc: implement `ReallocFunc` > rust: alloc: make `allocator` module public > rust: alloc: implement `Allocator` for `Kmalloc` > rust: alloc: add module `allocator_test` > rust: alloc: implement `Vmalloc` allocator > rust: alloc: implement `KVmalloc` allocator > rust: alloc: add __GFP_NOWARN to `Flags` > rust: alloc: implement kernel `Box` > rust: treewide: switch to our kernel `Box` type > rust: alloc: remove extension of std's `Box` > rust: alloc: add `Box` to prelude > rust: alloc: implement kernel `Vec` type > rust: alloc: implement `IntoIterator` for `Vec` > rust: alloc: implement `collect` for `IntoIter` > rust: treewide: switch to the kernel `Vec` type > rust: alloc: remove `VecExt` extension > rust: alloc: add `Vec` to prelude > rust: error: use `core::alloc::LayoutError` > rust: error: check for config `test` in `Error::name` > rust: alloc: implement `contains` for `Flags` > rust: alloc: implement `Cmalloc` in module allocator_test > rust: str: test: replace `alloc::format` > rust: alloc: update module comment of alloc.rs > kbuild: rust: remove the `alloc` crate and `GlobalAlloc` > MAINTAINERS: add entry for the Rust `alloc` module > > MAINTAINERS | 7 + > drivers/block/rnull.rs | 4 +- > rust/Makefile | 43 +- > rust/bindings/bindings_helper.h | 1 + > rust/exports.c | 1 - > rust/helpers/helpers.c | 1 + > rust/helpers/slab.c | 6 + > rust/helpers/vmalloc.c | 9 + > rust/kernel/alloc.rs | 150 ++++- > rust/kernel/alloc/allocator.rs | 210 +++++-- > rust/kernel/alloc/allocator_test.rs | 95 +++ > rust/kernel/alloc/box_ext.rs | 89 --- > rust/kernel/alloc/kbox.rs | 456 ++++++++++++++ > rust/kernel/alloc/kvec.rs | 914 ++++++++++++++++++++++++++++ > rust/kernel/alloc/layout.rs | 91 +++ > rust/kernel/alloc/vec_ext.rs | 185 ------ > rust/kernel/error.rs | 6 +- > rust/kernel/init.rs | 95 +-- > rust/kernel/init/__internal.rs | 2 +- > rust/kernel/lib.rs | 2 +- > rust/kernel/prelude.rs | 5 +- > rust/kernel/rbtree.rs | 49 +- > rust/kernel/str.rs | 35 +- > rust/kernel/sync/arc.rs | 17 +- > rust/kernel/sync/condvar.rs | 4 +- > rust/kernel/sync/lock/mutex.rs | 2 +- > rust/kernel/sync/lock/spinlock.rs | 2 +- > rust/kernel/sync/locked_by.rs | 2 +- > rust/kernel/types.rs | 52 +- > rust/kernel/uaccess.rs | 17 +- > rust/kernel/workqueue.rs | 20 +- > rust/macros/lib.rs | 12 +- > samples/rust/rust_minimal.rs | 4 +- > scripts/Makefile.build | 4 +- > scripts/generate_rust_analyzer.py | 11 +- > 35 files changed, 2025 insertions(+), 578 deletions(-) > create mode 100644 rust/helpers/vmalloc.c > 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 > create mode 100644 rust/kernel/alloc/layout.rs > delete mode 100644 rust/kernel/alloc/vec_ext.rs > > > base-commit: 7f4a2c6cacb0efad2bd9ae5062ab1b75e13c6c1f ~~ Lina
