Commit Graph
22 Commits
Author SHA1 Message Date
Andreas Hindborg 3253aba340 rust: block: introduce kernel::block::mq module
Add initial abstractions for working with blk-mq.

This patch is a maintained, refactored subset of code originally published
by Wedson Almeida Filho <[email protected]> [1].

[1] https://github.com/wedsonaf/linux/tree/f2cfd2fe0e2ca4e90994f96afe268bbd4382a891/rust/kernel/blk/mq.rs

Cc: Wedson Almeida Filho <[email protected]>
Signed-off-by: Andreas Hindborg <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
2024-06-14 07:45:04 -06:00
Miguel Ojeda 00280272a0 rust: kernel: remove redundant imports
Rust's `unused_imports` lint covers both unused and redundant imports.
In the upcoming 1.78.0, the lint detects more cases of redundant imports
[1], e.g.:

    error: the item `bindings` is imported redundantly
      --> rust/kernel/print.rs:38:9
       |
    38 |     use crate::bindings;
       |         ^^^^^^^^^^^^^^^ the item `bindings` is already defined by prelude

Most cases are `use crate::bindings`, plus a few other items like `Box`.
Thus clean them up.

Note that, in the `bindings` case, the message "defined by prelude"
above means the extern prelude, i.e. the `--extern` flags we pass.

Link: https://github.com/rust-lang/rust/pull/117772 [1]
Reviewed-by: Alice Ryhl <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>
2024-05-05 19:22:25 +02:00
Wedson Almeida Filho 2c1092853f rust: kernel: remove usage of allocator_api unstable feature
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.

Reviewed-by: Benno Lossin <[email protected]>
Signed-off-by: Wedson Almeida Filho <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>
2024-04-16 22:50:04 +02:00
Wedson Almeida Filho 5ab560ce12 rust: alloc: update VecExt to take allocation flags
We also rename the methods by removing the `try_` prefix since the names
are available due to our usage of the `no_global_oom_handling` config
when building the `alloc` crate.

Reviewed-by: Boqun Feng <[email protected]>
Signed-off-by: Wedson Almeida Filho <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>
2024-04-16 22:50:04 +02:00
Valentin Obst 69d5fbb015 rust: error: improve unsafe code in example
The `from_err_ptr` function is safe. There is no need for the call to it
to be inside the unsafe block.

Reword the SAFETY comment to provide a better justification of why the
FFI call is safe.

Signed-off-by: Valentin Obst <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Trevor Gross <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>
2024-02-18 21:22:27 +01:00
Miguel Ojeda bc2e7d5c29 rust: support srctree-relative links
Some of our links use relative paths in order to point to files in the
source tree, e.g.:

    //! C header: [`include/linux/printk.h`](../../../../include/linux/printk.h)
    /// [`struct mutex`]: ../../../../include/linux/mutex.h

These are problematic because they are hard to maintain and do not support
`O=` builds.

Instead, provide support for `srctree`-relative links, e.g.:

    //! C header: [`include/linux/printk.h`](srctree/include/linux/printk.h)
    /// [`struct mutex`]: srctree/include/linux/mutex.h

The links are fixed after `rustdoc` generation to be based on the absolute
path to the source tree.

Essentially, this is the automatic version of Tomonori's fix [1],
suggested by Gary [2].

Suggested-by: Gary Guo <[email protected]>
Reported-by: FUJITA Tomonori <[email protected]>
Closes: https://lore.kernel.org/r/[email protected] [1]
Fixes: 48fadf4400 ("docs: Move rustdoc output, cross-reference it")
Link: https://lore.kernel.org/rust-for-linux/20231026154525.6d14b495@eugeo/ [2]
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>
2023-12-21 20:54:17 +01:00
Benno Lossin 88c2e1169f rust: macros: improve #[vtable] documentation
Traits marked with `#[vtable]` need to provide default implementations
for optional functions. The C side represents these with `NULL` in the
vtable, so the default functions are never actually called. We do not
want to replicate the default behavior from C in Rust, because that is
not maintainable. Therefore we should use `build_error` in those default
implementations. The error message for that is provided at
`kernel::error::VTABLE_DEFAULT_ERROR`.

Signed-off-by: Benno Lossin <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Reviewed-by: Andreas Hindborg <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Finn Behrens <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Wrapped paragraph to 80 as requested and capitalized sentence. ]
Signed-off-by: Miguel Ojeda <[email protected]>
2023-12-14 20:14:01 +01:00
Manmohan Shukla 2a7e0a52ec rust: error: Markdown style nit
This patch fixes a trivial markdown style nit in the `SAFETY` comment.

Signed-off-by: Manmohan Shukla <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Jianguo Bao <[email protected]>
Reviewed-by: Vincenzo Palazzo <[email protected]>
Reviewed-by: Finn Behrens <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Andreas Hindborg <[email protected]>
Fixes: c7e20faa5f ("rust: error: Add Error::to_ptr()")
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>
2023-10-12 22:58:52 +02:00
Wedson Almeida Filho 17bfcd6a81 rust: error: fix the description for ECHILD
A mistake was made and the description of `ECHILD` is wrong (it reuses
the description of `ENOEXEC`). This fixes it to reflect what's in
`errno-base.h`.

Signed-off-by: Wedson Almeida Filho <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Reviewed-by: Trevor Gross <[email protected]>
Reviewed-by: Finn Behrens <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Fixes: 266def2a0f ("rust: error: add codes from `errno-base.h`")
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
[ Use the plural, as noticed by Benno. ]
Signed-off-by: Miguel Ojeda <[email protected]>
2023-10-12 22:58:28 +02:00
Gary Guo d2e3115d71 rust: error: impl Debug for Error with errname() integration
Integrate the `Error` type with `errname()` by providing a new
`name()` method.

Then, implement `Debug` for the type using the new method.

[ Miguel: under `CONFIG_SYMBOLIC_ERRNAME=n`, `errname()` is a
  `static inline`, so added a helper to support that case,
  like we had in the `rust` branch. Also moved `#include` up
  and reworded commit message for clarity. ]

Co-developed-by: Wedson Almeida Filho <[email protected]>
Signed-off-by: Wedson Almeida Filho <[email protected]>
Co-developed-by: Sven Van Asbroeck <[email protected]>
Signed-off-by: Sven Van Asbroeck <[email protected]>
Signed-off-by: Gary Guo <[email protected]>
Signed-off-by: Alice Ryhl <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>
2023-06-13 01:24:42 +02:00
Alice Ryhl e37b654c37 rust: error: add missing error codes
This adds the error codes from `include/linux/errno.h` to the list of
Rust error constants. These errors were not included originally, because
they are not supposed to be visible from userspace. However, they are
still a perfectly valid error to use when writing a kernel driver. For
example, you might want to return ERESTARTSYS if you receive a signal
during a call to `schedule`.

This patch inserts an annotation to skip rustfmt on the list of error
codes. Without it, three of the error codes are split over several
lines, which looks terribly inconsistent.

Signed-off-by: Alice Ryhl <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>
2023-05-31 18:53:10 +02:00
Alice Ryhl 4a59081c09 rust: error: allow specifying error type on Result
Currently, if the `kernel::error::Result` type is in scope (which is
often is, since it's in the kernel's prelude), you cannot write
`Result<T, SomeOtherErrorType>` when you want to use a different error
type than `kernel::error::Error`.

To solve this we change the error type from being hard-coded to just
being a default generic parameter. This still lets you write `Result<T>`
when you just want to use the `Error` error type, but also lets you
write `Result<T, SomeOtherErrorType>` when necessary.

Signed-off-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Asahi Lina <[email protected]>
Reviewed-by: Andreas Hindborg <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>
2023-05-31 18:53:10 +02:00
Wedson Almeida Filho ef4dc4cc70 rust: error: Add from_result() helper
Add a helper function to easily return C result codes from a Rust function
that calls functions which return a Result<T>.

Lina: Imported from rust-for-linux/rust, originally developed by Wedson
as part of file_operations.rs. Added the allow() flags since there is no
user in the kernel crate yet and fixed a typo in a comment. Replaced the
macro with a function taking a closure, per discussion on the ML.

Co-developed-by: Fox Chen <[email protected]>
Signed-off-by: Fox Chen <[email protected]>
Co-developed-by: Miguel Ojeda <[email protected]>
Signed-off-by: Miguel Ojeda <[email protected]>
Signed-off-by: Wedson Almeida Filho <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Signed-off-by: Asahi Lina <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>
2023-04-12 18:41:04 +02:00
Sven Van Asbroeck 752417b3f0 rust: error: Add a helper to convert a C ERR_PTR to a Result
Some kernel C API functions return a pointer which embeds an optional
`errno`. Callers are supposed to check the returned pointer with
`IS_ERR()` and if this returns `true`, retrieve the `errno` using
`PTR_ERR()`.

Create a Rust helper function to implement the Rust equivalent:
transform a `*mut T` to `Result<*mut T>`.

Lina: Imported from rust-for-linux/linux, with subsequent refactoring
and contributions squashed in and attributed below. Renamed the function
to from_err_ptr().

Co-developed-by: Boqun Feng <[email protected]>
Signed-off-by: Boqun Feng <[email protected]>
Co-developed-by: Miguel Ojeda <[email protected]>
Signed-off-by: Miguel Ojeda <[email protected]>
Co-developed-by: Fox Chen <[email protected]>
Signed-off-by: Fox Chen <[email protected]>
Co-developed-by: Gary Guo <[email protected]>
Signed-off-by: Gary Guo <[email protected]>
Signed-off-by: Sven Van Asbroeck <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Signed-off-by: Asahi Lina <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Add a removal of `#[allow(dead_code)]`. ]
Signed-off-by: Miguel Ojeda <[email protected]>
2023-04-12 18:41:04 +02:00
Wedson Almeida Filho 086fbfa3b3 rust: error: Add to_result() helper
Add a to_result() helper to convert kernel C return values to a Rust
Result, mapping >=0 values to Ok(()) and negative values to Err(...),
with Error::from_errno() ensuring that the errno is within range.

Lina: Imported from rust-for-linux/rust, originally developed by Wedson
as part of the AMBA device driver support.

Signed-off-by: Wedson Almeida Filho <[email protected]>
Reviewed-by: Andreas Hindborg <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Signed-off-by: Asahi Lina <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Add a removal of `#[allow(dead_code)]`. ]
Signed-off-by: Miguel Ojeda <[email protected]>
2023-04-12 18:41:04 +02:00
Miguel Ojeda 6551a7fe0a rust: error: Add Error::from_errno{_unchecked}()
Add a function to create `Error` values out of a kernel error return,
which safely upholds the invariant that the error code is well-formed
(negative and greater than -MAX_ERRNO). If a malformed code is passed
in, it will be converted to EINVAL.

Lina: Imported from rust-for-linux/rust as authored by Miguel and Fox
with refactoring from Wedson, renamed from_kernel_errno() to
from_errno().

Co-developed-by: Fox Chen <[email protected]>
Signed-off-by: Fox Chen <[email protected]>
Co-developed-by: Wedson Almeida Filho <[email protected]>
Signed-off-by: Wedson Almeida Filho <[email protected]>
Signed-off-by: Miguel Ojeda <[email protected]>
Reviewed-by: Andreas Hindborg <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Signed-off-by: Asahi Lina <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Mark the new associated functions as `#[allow(dead_code)]`. ]
Signed-off-by: Miguel Ojeda <[email protected]>
2023-04-12 18:41:04 +02:00
Asahi Lina c7e20faa5f rust: error: Add Error::to_ptr()
This is the Rust equivalent to ERR_PTR(), for use in C callbacks.
Marked as #[allow(dead_code)] for now, since it does not have any
consumers yet.

Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Signed-off-by: Asahi Lina <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>
2023-04-12 18:41:04 +02:00
Asahi Lina 46384d0990 rust: error: Rename to_kernel_errno() -> to_errno()
This is kernel code, so specifying "kernel" is redundant. Let's simplify
things and just call it to_errno().

Reviewed-by: Gary Guo <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Signed-off-by: Asahi Lina <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>
2023-04-12 18:41:04 +02:00
Wedson Almeida Filho 76e2c2d9a2 rust: error: add From implementations for Error
Add a set of `From` implementations for the `Error` kernel type.

These implementations allow to easily convert from standard Rust
error types to the usual kernel errors based on one of the `E*`
integer codes.

On top of that, the question mark Rust operator (`?`) implicitly
performs a conversion on the error value using the `From` trait
when propagating. Thus it is extra convenient to use.

For instance, a kernel function that needs to convert a `i64` into
a `i32` and to bubble up the error as a kernel error may write:

    fn f(x: i64) -> Result<...> {
        ...
        let y = i32::try_from(x)?;
        ...
    }

which will transform the `TryFromIntError` into an `Err(EINVAL)`.

Co-developed-by: Adam Bratschi-Kaye <[email protected]>
Signed-off-by: Adam Bratschi-Kaye <[email protected]>
Co-developed-by: Nándor István Krácser <[email protected]>
Signed-off-by: Nándor István Krácser <[email protected]>
Signed-off-by: Wedson Almeida Filho <[email protected]>
Reviewed-by: Finn Behrens <[email protected]>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <[email protected]>
2022-12-04 01:59:15 +01:00
Viktor Garske 266def2a0f rust: error: add codes from errno-base.h
Only a few codes were added so far. With the `declare_err!`
macro in place, add the remaining ones (which is most of them)
from `include/uapi/asm-generic/errno-base.h`.

Co-developed-by: Wedson Almeida Filho <[email protected]>
Signed-off-by: Wedson Almeida Filho <[email protected]>
Signed-off-by: Viktor Garske <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <[email protected]>
2022-12-04 01:59:15 +01:00
Finn Behrens 4b0c68bd0d rust: error: declare errors using macro
Add a macro to declare errors, which simplifies the work needed to
add each one, avoids repetition of the code and makes it easier to
change the way they are declared.

Signed-off-by: Finn Behrens <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <[email protected]>
2022-12-04 01:59:15 +01:00
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 <[email protected]>
Co-developed-by: Alex Gaynor <[email protected]>
Signed-off-by: Alex Gaynor <[email protected]>
Co-developed-by: Geoffrey Thomas <[email protected]>
Signed-off-by: Geoffrey Thomas <[email protected]>
Co-developed-by: Finn Behrens <[email protected]>
Signed-off-by: Finn Behrens <[email protected]>
Co-developed-by: Adam Bratschi-Kaye <[email protected]>
Signed-off-by: Adam Bratschi-Kaye <[email protected]>
Co-developed-by: Sven Van Asbroeck <[email protected]>
Signed-off-by: Sven Van Asbroeck <[email protected]>
Co-developed-by: Gary Guo <[email protected]>
Signed-off-by: Gary Guo <[email protected]>
Co-developed-by: Boris-Chengbiao Zhou <[email protected]>
Signed-off-by: Boris-Chengbiao Zhou <[email protected]>
Co-developed-by: Boqun Feng <[email protected]>
Signed-off-by: Boqun Feng <[email protected]>
Co-developed-by: Fox Chen <[email protected]>
Signed-off-by: Fox Chen <[email protected]>
Co-developed-by: Viktor Garske <[email protected]>
Signed-off-by: Viktor Garske <[email protected]>
Co-developed-by: Dariusz Sosnowski <[email protected]>
Signed-off-by: Dariusz Sosnowski <[email protected]>
Co-developed-by: Léo Lanteri Thauvin <[email protected]>
Signed-off-by: Léo Lanteri Thauvin <[email protected]>
Co-developed-by: Niklas Mohrin <[email protected]>
Signed-off-by: Niklas Mohrin <[email protected]>
Co-developed-by: Milan Landaverde <[email protected]>
Signed-off-by: Milan Landaverde <[email protected]>
Co-developed-by: Morgan Bartlett <[email protected]>
Signed-off-by: Morgan Bartlett <[email protected]>
Co-developed-by: Maciej Falkowski <[email protected]>
Signed-off-by: Maciej Falkowski <[email protected]>
Co-developed-by: Nándor István Krácser <[email protected]>
Signed-off-by: Nándor István Krácser <[email protected]>
Co-developed-by: David Gow <[email protected]>
Signed-off-by: David Gow <[email protected]>
Co-developed-by: John Baublitz <[email protected]>
Signed-off-by: John Baublitz <[email protected]>
Co-developed-by: Björn Roy Baron <[email protected]>
Signed-off-by: Björn Roy Baron <[email protected]>
Signed-off-by: Wedson Almeida Filho <[email protected]>
Co-developed-by: Miguel Ojeda <[email protected]>
Signed-off-by: Miguel Ojeda <[email protected]>
2022-09-28 08:58:24 +02:00