linux-toradex.git/rust/kernel/alloc/kbox.rs, branch v6.14-rc6 Linux kernel for Apalis and Colibri modules rust: kernel: add improved version of `ForeignOwnable::borrow_mut` 2025-01-13T22:46:07+00:00 Alice Ryhl aliceryhl@google.com 2024-11-20T11:46:05+00:00 c27e705cb2b71769dbb4bb1bee1920d2fa01a597 Previously, the `ForeignOwnable` trait had a method called `borrow_mut` that was intended to provide mutable access to the inner value. However, the method accidentally made it possible to change the address of the object being modified, which usually isn't what we want. (And when we want that, it can be done by calling `from_foreign` and `into_foreign`, like how the old `borrow_mut` was implemented.) In this patch, we introduce an alternate definition of `borrow_mut` that solves the previous problem. Conceptually, given a pointer type `P` that implements `ForeignOwnable`, the `borrow_mut` method gives you the same kind of access as an `&mut P` would, except that it does not let you change the pointer `P` itself. This is analogous to how the existing `borrow` method provides the same kind of access to the inner value as an `&P`. Note that for types like `Arc`, having an `&mut Arc<T>` only gives you immutable access to the inner `T`. This is because mutable references assume exclusive access, but there might be other handles to the same reference counted value, so the access isn't exclusive. The `Arc` type implements this by making `borrow_mut` return the same type as `borrow`. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Signed-off-by: Tamir Duberstein <tamird@gmail.com> Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20241120-borrow-mut-v6-6-80dbadd00951@gmail.com [ Updated to `crate::ffi::`. Reworded title slightly. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> 
Previously, the `ForeignOwnable` trait had a method called `borrow_mut`
that was intended to provide mutable access to the inner value. However,
the method accidentally made it possible to change the address of the
object being modified, which usually isn't what we want. (And when we
want that, it can be done by calling `from_foreign` and `into_foreign`,
like how the old `borrow_mut` was implemented.)

In this patch, we introduce an alternate definition of `borrow_mut` that
solves the previous problem. Conceptually, given a pointer type `P` that
implements `ForeignOwnable`, the `borrow_mut` method gives you the same
kind of access as an `&mut P` would, except that it does not let you
change the pointer `P` itself.

This is analogous to how the existing `borrow` method provides the same
kind of access to the inner value as an `&P`.

Note that for types like `Arc`, having an `&mut Arc<T>` only gives you
immutable access to the inner `T`. This is because mutable references
assume exclusive access, but there might be other handles to the same
reference counted value, so the access isn't exclusive. The `Arc` type
implements this by making `borrow_mut` return the same type as `borrow`.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241120-borrow-mut-v6-6-80dbadd00951@gmail.com
[ Updated to `crate::ffi::`. Reworded title slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
rust: kernel: change `ForeignOwnable` pointer to mut 2025-01-13T22:45:31+00:00 Tamir Duberstein tamird@gmail.com 2024-11-20T11:46:03+00:00 14686571a914833e38eef0f907202f58df4ffcd2 It is slightly more convenient to operate on mut pointers, and this also properly conveys the desired ownership semantics of the trait. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Signed-off-by: Tamir Duberstein <tamird@gmail.com> Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20241120-borrow-mut-v6-4-80dbadd00951@gmail.com [ Reworded title slightly. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> 
It is slightly more convenient to operate on mut pointers, and this also
properly conveys the desired ownership semantics of the trait.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241120-borrow-mut-v6-4-80dbadd00951@gmail.com
[ Reworded title slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
rust: types: avoid `as` casts 2025-01-13T22:45:30+00:00 Tamir Duberstein tamird@gmail.com 2024-11-20T11:46:01+00:00 aa991a2a819535a0014e1159b455b64e3db87510 Replace `as` casts with `cast{,_mut}` calls which are a bit safer. In one instance, remove an unnecessary `as` cast without replacement. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Signed-off-by: Tamir Duberstein <tamird@gmail.com> Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20241120-borrow-mut-v6-2-80dbadd00951@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org> 
Replace `as` casts with `cast{,_mut}` calls which are a bit safer.

In one instance, remove an unnecessary `as` cast without replacement.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241120-borrow-mut-v6-2-80dbadd00951@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
rust: alloc: align Debug implementation for Box with Display 2024-12-17T23:56:05+00:00 Guangbo Cui 2407018371@qq.com 2024-11-11T13:51:27+00:00 517743c4e303252cd8c1a1fb1bed28e7d94d4678 Ensure consistency between `Debug` and `Display` for `Box` by updating `Debug` to match the new `Display` style. Acked-by: Danilo Krummrich <dakr@kernel.org> Signed-off-by: Guangbo Cui <2407018371@qq.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/tencent_1FC0BC283DA65DD81A8A14EEF25563934E05@qq.com [ Reworded title. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> 
Ensure consistency between `Debug` and `Display` for `Box` by
updating `Debug` to match the new `Display` style.

Acked-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Guangbo Cui <2407018371@qq.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/tencent_1FC0BC283DA65DD81A8A14EEF25563934E05@qq.com
[ Reworded title. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
rust: alloc: implement Display for Box 2024-12-17T23:54:31+00:00 Guangbo Cui 2407018371@qq.com 2024-11-11T13:40:41+00:00 21e08aa59a9a0b665b051a8919ec80a872807cfb Currently `impl Display` is missing for `Box<T, A>`, as a result, things like using `Box<..>` directly as an operand in `pr_info!()` are impossible, which is less ergonomic compared to `Box` in Rust std. Therefore add `impl Display` for `Box`. Acked-by: Danilo Krummrich <dakr@kernel.org> Suggested-by: Boqun Feng <boqun.feng@gmail.com> Link: https://github.com/Rust-for-Linux/linux/issues/1126 Signed-off-by: Guangbo Cui <2407018371@qq.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/tencent_2AD25C6A6898D3A598CBA54BB6AF59BB900A@qq.com [ Reworded title. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> 
Currently `impl Display` is missing for `Box<T, A>`, as a result,
things like using `Box<..>` directly as an operand in `pr_info!()`
are impossible, which is less ergonomic compared to `Box` in Rust
std.

Therefore add `impl Display` for `Box`.

Acked-by: Danilo Krummrich <dakr@kernel.org>
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://github.com/Rust-for-Linux/linux/issues/1126
Signed-off-by: Guangbo Cui <2407018371@qq.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/tencent_2AD25C6A6898D3A598CBA54BB6AF59BB900A@qq.com
[ Reworded title. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
rust: use custom FFI integer types 2024-11-10T22:58:00+00:00 Gary Guo gary@garyguo.net 2024-09-13T21:29:23+00:00 d072acda4862f095ec9056979b654cc06a22cc68 Currently FFI integer types are defined in libcore. This commit creates the `ffi` crate and asks bindgen to use that crate for FFI integer types instead of `core::ffi`. This commit is preparatory and no type changes are made in this commit yet. Signed-off-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20240913213041.395655-4-gary@garyguo.net [ Added `rustdoc`, `rusttest` and KUnit tests support. Rebased on top of `rust-next` (e.g. migrated more `core::ffi` cases). Reworded crate docs slightly and formatted. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> 
Currently FFI integer types are defined in libcore. This commit creates
the `ffi` crate and asks bindgen to use that crate for FFI integer types
instead of `core::ffi`.

This commit is preparatory and no type changes are made in this commit
yet.

Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240913213041.395655-4-gary@garyguo.net
[ Added `rustdoc`, `rusttest` and KUnit tests support. Rebased on top of
  `rust-next` (e.g. migrated more `core::ffi` cases). Reworded crate
  docs slightly and formatted. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
rust: alloc: implement kernel `Box` 2024-10-15T20:56:59+00:00 Danilo Krummrich dakr@kernel.org 2024-10-04T15:41:15+00:00 c8cfa8d0c0b10be216861fe904ea68978b1dcc97 `Box` provides the simplest way to allocate memory for a generic type with one of the kernel's allocators, e.g. `Kmalloc`, `Vmalloc` or `KVmalloc`. In contrast to Rust's `Box` type, the kernel `Box` type considers the kernel's GFP flags for all appropriate functions, always reports allocation failures through `Result<_, AllocError>` and remains independent from unstable features. Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20241004154149.93856-12-dakr@kernel.org [ Added backticks, fixed typos. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> 
`Box` provides the simplest way to allocate memory for a generic type
with one of the kernel's allocators, e.g. `Kmalloc`, `Vmalloc` or
`KVmalloc`.

In contrast to Rust's `Box` type, the kernel `Box` type considers the
kernel's GFP flags for all appropriate functions, always reports
allocation failures through `Result<_, AllocError>` and remains
independent from unstable features.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-12-dakr@kernel.org
[ Added backticks, fixed typos. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>