linux-stable.git/rust/kernel/error.rs, branch v6.10

rust: kernel: remove redundant imports

2024-05-05T17:22:25+00:00

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 
Link: https://lore.kernel.org/r/20240401212303.537355-3-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

rust: kernel: remove usage of `allocator_api` unstable feature

2024-04-16T20:50:04+00:00

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 
Signed-off-by: Wedson Almeida Filho 
Link: https://lore.kernel.org/r/20240328013603.206764-11-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda

rust: alloc: update `VecExt` to take allocation flags

2024-04-16T20:50:04+00:00

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 
Signed-off-by: Wedson Almeida Filho 
Reviewed-by: Benno Lossin 
Link: https://lore.kernel.org/r/20240328013603.206764-8-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda

rust: error: improve unsafe code in example

2024-02-18T20:22:27+00:00

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 
Reviewed-by: Martin Rodriguez Reboredo 
Reviewed-by: Alice Ryhl 
Reviewed-by: Trevor Gross 
Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-2-0c8af94ed7de@valentinobst.de
Signed-off-by: Miguel Ojeda

rust: support `srctree`-relative links

2023-12-21T19:54:17+00:00

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 
Reported-by: FUJITA Tomonori 
Closes: https://lore.kernel.org/r/20231026.204058.2167744626131849993.fujita.tomonori@gmail.com [1]
Fixes: 48fadf440075 ("docs: Move rustdoc output, cross-reference it")
Link: https://lore.kernel.org/rust-for-linux/20231026154525.6d14b495@eugeo/ [2]
Reviewed-by: Martin Rodriguez Reboredo 
Reviewed-by: Benno Lossin 
Link: https://lore.kernel.org/r/20231215235428.243211-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

rust: macros: improve `#[vtable]` documentation

2023-12-14T19:14:01+00:00

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 
Reviewed-by: Martin Rodriguez Reboredo 
Reviewed-by: Andreas Hindborg 
Reviewed-by: Alice Ryhl 
Reviewed-by: Finn Behrens 
Link: https://lore.kernel.org/r/20231026201855.1497680-1-benno.lossin@proton.me
[ Wrapped paragraph to 80 as requested and capitalized sentence. ]
Signed-off-by: Miguel Ojeda

rust: error: Markdown style nit

2023-10-12T20:58:52+00:00

This patch fixes a trivial markdown style nit in the `SAFETY` comment.

Signed-off-by: Manmohan Shukla 
Reviewed-by: Alice Ryhl 
Reviewed-by: Jianguo Bao 
Reviewed-by: Vincenzo Palazzo 
Reviewed-by: Finn Behrens 
Reviewed-by: Benno Lossin 
Reviewed-by: Andreas Hindborg 
Fixes: c7e20faa5fca ("rust: error: Add Error::to_ptr()")
Link: https://lore.kernel.org/r/20230906204857.85619-1-manmshuk@gmail.com
Signed-off-by: Miguel Ojeda

rust: error: fix the description for `ECHILD`

2023-10-12T20:58:28+00:00

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 
Reviewed-by: Martin Rodriguez Reboredo 
Reviewed-by: Trevor Gross 
Reviewed-by: Finn Behrens 
Reviewed-by: Alice Ryhl 
Fixes: 266def2a0f5b ("rust: error: add codes from `errno-base.h`")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230930144958.46051-1-wedsonaf@gmail.com
[ Use the plural, as noticed by Benno. ]
Signed-off-by: Miguel Ojeda

rust: error: `impl Debug` for `Error` with `errname()` integration

2023-06-12T23:24:42+00:00

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 
Signed-off-by: Wedson Almeida Filho 
Co-developed-by: Sven Van Asbroeck 
Signed-off-by: Sven Van Asbroeck 
Signed-off-by: Gary Guo 
Signed-off-by: Alice Ryhl 
Reviewed-by: Martin Rodriguez Reboredo 
Link: https://lore.kernel.org/r/20230531174450.3733220-1-aliceryhl@google.com
Signed-off-by: Miguel Ojeda

rust: error: add missing error codes

2023-05-31T16:53:10+00:00

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 
Reviewed-by: Martin Rodriguez Reboredo 
Link: https://lore.kernel.org/r/20230504064854.774820-1-aliceryhl@google.com
Signed-off-by: Miguel Ojeda