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Linus Torvalds a031fe8d1d Rust changes for v6.6
In terms of lines, most changes this time are on the pinned-init API
 and infrastructure. While we have a Rust version upgrade, and thus a
 bunch of changes from the vendored 'alloc' crate as usual, this time
 those do not account for many lines.
 
 Toolchain and infrastructure:
 
  - Upgrade to Rust 1.71.1. This is the second such upgrade, which is a
    smaller jump compared to the last time.
 
    This version allows us to remove the '__rust_*' allocator functions
    -- the compiler now generates them as expected, thus now our
    'KernelAllocator' is used.
 
    It also introduces the 'offset_of!' macro in the standard library
    (as an unstable feature) which we will need soon. So far, we were
    using a declarative macro as a prerequisite in some not-yet-landed
    patch series, which did not support sub-fields (i.e. nested structs):
 
        #[repr(C)]
        struct S {
            a: u16,
            b: (u8, u8),
        }
 
        assert_eq!(offset_of!(S, b.1), 3);
 
  - Upgrade to bindgen 0.65.1. This is the first time we upgrade its
    version.
 
    Given it is a fairly big jump, it comes with a fair number of
    improvements/changes that affect us, such as a fix needed to support
    LLVM 16 as well as proper support for '__noreturn' C functions, which
    are now mapped to return the '!' type in Rust:
 
        void __noreturn f(void); // C
        pub fn f() -> !;         // Rust
 
  - 'scripts/rust_is_available.sh' improvements and fixes.
 
    This series takes care of all the issues known so far and adds a few
    new checks to cover for even more cases, plus adds some more help
    texts. All this together will hopefully make problematic setups
    easier to identify and to be solved by users building the kernel.
 
    In addition, it adds a test suite which covers all branches of the
    shell script, as well as tests for the issues found so far.
 
  - Support rust-analyzer for out-of-tree modules too.
 
  - Give 'cfg's to rust-analyzer for the 'core' and 'alloc' crates.
 
  - Drop 'scripts/is_rust_module.sh' since it is not needed anymore.
 
 Macros crate:
 
  - New 'paste!' proc macro.
 
    This macro is a more flexible version of 'concat_idents!': it allows
    the resulting identifier to be used to declare new items and it
    allows to transform the identifiers before concatenating them, e.g.
 
        let x_1 = 42;
        paste!(let [<x _2>] = [<x _1>];);
        assert!(x_1 == x_2);
 
    The macro is then used for several of the pinned-init API changes in
    this pull.
 
 Pinned-init API:
 
  - Make '#[pin_data]' compatible with conditional compilation of fields,
    allowing to write code like:
 
        #[pin_data]
        pub struct Foo {
            #[cfg(CONFIG_BAR)]
            a: Bar,
            #[cfg(not(CONFIG_BAR))]
            a: Baz,
        }
 
  - New '#[derive(Zeroable)]' proc macro for the 'Zeroable' trait, which
    allows 'unsafe' implementations for structs where every field
    implements the 'Zeroable' trait, e.g.:
 
        #[derive(Zeroable)]
        pub struct DriverData {
            id: i64,
            buf_ptr: *mut u8,
            len: usize,
        }
 
  - Add '..Zeroable::zeroed()' syntax to the 'pin_init!'  macro for
    zeroing all other fields, e.g.:
 
        pin_init!(Buf {
            buf: [1; 64],
            ..Zeroable::zeroed()
        });
 
  - New '{,pin_}init_array_from_fn()' functions to create array
    initializers given a generator function, e.g.:
 
        let b: Box<[usize; 1_000]> = Box::init::<Error>(
            init_array_from_fn(|i| i)
        ).unwrap();
 
        assert_eq!(b.len(), 1_000);
        assert_eq!(b[123], 123);
 
  - New '{,pin_}chain' methods for '{,Pin}Init<T, E>' that allow to
    execute a closure on the value directly after initialization, e.g.:
 
        let foo = init!(Foo {
            buf <- init::zeroed()
        }).chain(|foo| {
            foo.setup();
            Ok(())
        });
 
  - Support arbitrary paths in init macros, instead of just identifiers
    and generic types.
 
  - Implement the 'Zeroable' trait for the 'UnsafeCell<T>' and
    'Opaque<T>' types.
 
  - Make initializer values inaccessible after initialization.
 
  - Make guards in the init macros hygienic.
 
 'allocator' module:
 
  - Use 'krealloc_aligned()' in 'KernelAllocator::alloc' preventing
    misaligned allocations when the Rust 1.71.1 upgrade is applied later
    in this pull.
 
    The equivalent fix for the previous compiler version (where
    'KernelAllocator' is not yet used) was merged into 6.5 already,
    which added the 'krealloc_aligned()' function used here.
 
  - Implement 'KernelAllocator::{realloc, alloc_zeroed}' for performance,
    using 'krealloc_aligned()' too, which forwards the call to the C API.
 
 'types' module:
 
  - Make 'Opaque' be '!Unpin', removing the need to add a 'PhantomPinned'
    field to Rust structs that contain C structs which must not be moved.
 
  - Make 'Opaque' use 'UnsafeCell' as the outer type, rather than inner.
 
 Documentation:
 
  - Suggest obtaining the source code of the Rust's 'core' library using
    the tarball instead of the repository.
 
 MAINTAINERS:
 
  - Andreas and Alice, from Samsung and Google respectively, are joining
    as reviewers of the "RUST" entry.
 
 As well as a few other minor changes and cleanups.
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Merge tag 'rust-6.6' of https://github.com/Rust-for-Linux/linux

Pull rust updates from Miguel Ojeda:
 "In terms of lines, most changes this time are on the pinned-init API
  and infrastructure. While we have a Rust version upgrade, and thus a
  bunch of changes from the vendored 'alloc' crate as usual, this time
  those do not account for many lines.

  Toolchain and infrastructure:

   - Upgrade to Rust 1.71.1. This is the second such upgrade, which is a
     smaller jump compared to the last time.

     This version allows us to remove the '__rust_*' allocator functions
     -- the compiler now generates them as expected, thus now our
     'KernelAllocator' is used.

     It also introduces the 'offset_of!' macro in the standard library
     (as an unstable feature) which we will need soon. So far, we were
     using a declarative macro as a prerequisite in some not-yet-landed
     patch series, which did not support sub-fields (i.e. nested
     structs):

         #[repr(C)]
         struct S {
             a: u16,
             b: (u8, u8),
         }

         assert_eq!(offset_of!(S, b.1), 3);

   - Upgrade to bindgen 0.65.1. This is the first time we upgrade its
     version.

     Given it is a fairly big jump, it comes with a fair number of
     improvements/changes that affect us, such as a fix needed to
     support LLVM 16 as well as proper support for '__noreturn' C
     functions, which are now mapped to return the '!' type in Rust:

         void __noreturn f(void); // C
         pub fn f() -> !;         // Rust

   - 'scripts/rust_is_available.sh' improvements and fixes.

     This series takes care of all the issues known so far and adds a
     few new checks to cover for even more cases, plus adds some more
     help texts. All this together will hopefully make problematic
     setups easier to identify and to be solved by users building the
     kernel.

     In addition, it adds a test suite which covers all branches of the
     shell script, as well as tests for the issues found so far.

   - Support rust-analyzer for out-of-tree modules too.

   - Give 'cfg's to rust-analyzer for the 'core' and 'alloc' crates.

   - Drop 'scripts/is_rust_module.sh' since it is not needed anymore.

  Macros crate:

   - New 'paste!' proc macro.

     This macro is a more flexible version of 'concat_idents!': it
     allows the resulting identifier to be used to declare new items and
     it allows to transform the identifiers before concatenating them,
     e.g.

         let x_1 = 42;
         paste!(let [<x _2>] = [<x _1>];);
         assert!(x_1 == x_2);

     The macro is then used for several of the pinned-init API changes
     in this pull.

  Pinned-init API:

   - Make '#[pin_data]' compatible with conditional compilation of
     fields, allowing to write code like:

         #[pin_data]
         pub struct Foo {
             #[cfg(CONFIG_BAR)]
             a: Bar,
             #[cfg(not(CONFIG_BAR))]
             a: Baz,
         }

   - New '#[derive(Zeroable)]' proc macro for the 'Zeroable' trait,
     which allows 'unsafe' implementations for structs where every field
     implements the 'Zeroable' trait, e.g.:

         #[derive(Zeroable)]
         pub struct DriverData {
             id: i64,
             buf_ptr: *mut u8,
             len: usize,
         }

   - Add '..Zeroable::zeroed()' syntax to the 'pin_init!' macro for
     zeroing all other fields, e.g.:

         pin_init!(Buf {
             buf: [1; 64],
             ..Zeroable::zeroed()
         });

   - New '{,pin_}init_array_from_fn()' functions to create array
     initializers given a generator function, e.g.:

         let b: Box<[usize; 1_000]> = Box::init::<Error>(
             init_array_from_fn(|i| i)
         ).unwrap();

         assert_eq!(b.len(), 1_000);
         assert_eq!(b[123], 123);

   - New '{,pin_}chain' methods for '{,Pin}Init<T, E>' that allow to
     execute a closure on the value directly after initialization, e.g.:

         let foo = init!(Foo {
             buf <- init::zeroed()
         }).chain(|foo| {
             foo.setup();
             Ok(())
         });

   - Support arbitrary paths in init macros, instead of just identifiers
     and generic types.

   - Implement the 'Zeroable' trait for the 'UnsafeCell<T>' and
     'Opaque<T>' types.

   - Make initializer values inaccessible after initialization.

   - Make guards in the init macros hygienic.

  'allocator' module:

   - Use 'krealloc_aligned()' in 'KernelAllocator::alloc' preventing
     misaligned allocations when the Rust 1.71.1 upgrade is applied
     later in this pull.

     The equivalent fix for the previous compiler version (where
     'KernelAllocator' is not yet used) was merged into 6.5 already,
     which added the 'krealloc_aligned()' function used here.

   - Implement 'KernelAllocator::{realloc, alloc_zeroed}' for
     performance, using 'krealloc_aligned()' too, which forwards the
     call to the C API.

  'types' module:

   - Make 'Opaque' be '!Unpin', removing the need to add a
     'PhantomPinned' field to Rust structs that contain C structs which
     must not be moved.

   - Make 'Opaque' use 'UnsafeCell' as the outer type, rather than
     inner.

  Documentation:

   - Suggest obtaining the source code of the Rust's 'core' library
     using the tarball instead of the repository.

  MAINTAINERS:

   - Andreas and Alice, from Samsung and Google respectively, are
     joining as reviewers of the "RUST" entry.

  As well as a few other minor changes and cleanups"

* tag 'rust-6.6' of https://github.com/Rust-for-Linux/linux: (42 commits)
  rust: init: update expanded macro explanation
  rust: init: add `{pin_}chain` functions to `{Pin}Init<T, E>`
  rust: init: make `PinInit<T, E>` a supertrait of `Init<T, E>`
  rust: init: implement `Zeroable` for `UnsafeCell<T>` and `Opaque<T>`
  rust: init: add support for arbitrary paths in init macros
  rust: init: add functions to create array initializers
  rust: init: add `..Zeroable::zeroed()` syntax for zeroing all missing fields
  rust: init: make initializer values inaccessible after initializing
  rust: init: wrap type checking struct initializers in a closure
  rust: init: make guards in the init macros hygienic
  rust: add derive macro for `Zeroable`
  rust: init: make `#[pin_data]` compatible with conditional compilation of fields
  rust: init: consolidate init macros
  docs: rust: clarify what 'rustup override' does
  docs: rust: update instructions for obtaining 'core' source
  docs: rust: add command line to rust-analyzer section
  scripts: generate_rust_analyzer: provide `cfg`s for `core` and `alloc`
  rust: bindgen: upgrade to 0.65.1
  rust: enable `no_mangle_with_rust_abi` Clippy lint
  rust: upgrade to Rust 1.71.1
  ...
2023-08-29 08:19:46 -07:00
Aakash Sen Sharma 08ab786556 rust: bindgen: upgrade to 0.65.1
In LLVM 16, anonymous items may return names like `(unnamed union at ..)`
rather than empty names [1], which breaks Rust-enabled builds because
bindgen assumed an empty name instead of detecting them via
`clang_Cursor_isAnonymous` [2]:

    $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc)
      RUSTC L rust/core.o
      BINDGEN rust/bindings/bindings_generated.rs
      BINDGEN rust/bindings/bindings_helpers_generated.rs
      BINDGEN rust/uapi/uapi_generated.rs
    thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9
    ...
    thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9
    ...

This was fixed in bindgen 0.62.0. Therefore, upgrade bindgen to
a more recent version, 0.65.1, to support LLVM 16.

Since bindgen 0.58.0 changed the `--{white,black}list-*` flags to
`--{allow,block}list-*` [3], update them on our side too.

In addition, bindgen 0.61.0 moved its CLI utility into a binary crate
called `bindgen-cli` [4]. Thus update the installation command in the
Quick Start guide.

Moreover, bindgen 0.61.0 changed the default functionality to bind
`size_t` to `usize` [5] and added the `--no-size_t-is-usize` flag
to not bind `size_t` as `usize`. Then bindgen 0.65.0 removed
the `--size_t-is-usize` flag [6]. Thus stop passing the flag to bindgen.

Finally, bindgen 0.61.0 added support for the `noreturn` attribute (in
its different forms) [7]. Thus remove the infinite loop in our Rust
panic handler after calling `BUG()`, since bindgen now correctly
generates a `BUG()` binding that returns `!` instead of `()`.

Link: 19e984ef8f [1]
Link: https://github.com/rust-lang/rust-bindgen/pull/2319 [2]
Link: https://github.com/rust-lang/rust-bindgen/pull/1990 [3]
Link: https://github.com/rust-lang/rust-bindgen/pull/2284 [4]
Link: cc78b6fdb6 [5]
Link: https://github.com/rust-lang/rust-bindgen/pull/2408 [6]
Link: https://github.com/rust-lang/rust-bindgen/issues/2094 [7]
Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com>
Closes: https://github.com/Rust-for-Linux/linux/issues/1013
Tested-by: Ariel Miculas <amiculas@cisco.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com
[ Reworded commit message. Mentioned the `bindgen-cli` binary crate
  change, linked to it and updated the Quick Start guide. Re-added a
  deleted "as" word in a code comment and reflowed comment to respect
  the maximum length. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-15 00:37:22 +02:00
Ariel Miculas 917b2e00b9 rust: helpers: sort includes alphabetically in rust/helpers.c
Sort the #include directives of rust/helpers.c alphabetically and add a
comment specifying this. The reason for this is to improve readability
and to be consistent with the other files with a similar approach within
'rust/'.

Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1003
Signed-off-by: Ariel Miculas <amiculas@cisco.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20230426204923.16195-1-amiculas@cisco.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-07 11:33:33 +02:00
Miguel Ojeda a66d733da8 rust: support running Rust documentation tests as KUnit ones
Rust has documentation tests: these are typically examples of
usage of any item (e.g. function, struct, module...).

They are very convenient because they are just written
alongside the documentation. For instance:

    /// Sums two numbers.
    ///
    /// ```
    /// assert_eq!(mymod::f(10, 20), 30);
    /// ```
    pub fn f(a: i32, b: i32) -> i32 {
        a + b
    }

In userspace, the tests are collected and run via `rustdoc`.
Using the tool as-is would be useful already, since it allows
to compile-test most tests (thus enforcing they are kept
in sync with the code they document) and run those that do not
depend on in-kernel APIs.

However, by transforming the tests into a KUnit test suite,
they can also be run inside the kernel. Moreover, the tests
get to be compiled as other Rust kernel objects instead of
targeting userspace.

On top of that, the integration with KUnit means the Rust
support gets to reuse the existing testing facilities. For
instance, the kernel log would look like:

    KTAP version 1
    1..1
        KTAP version 1
        # Subtest: rust_doctests_kernel
        1..59
        # rust_doctest_kernel_build_assert_rs_0.location: rust/kernel/build_assert.rs:13
        ok 1 rust_doctest_kernel_build_assert_rs_0
        # rust_doctest_kernel_build_assert_rs_1.location: rust/kernel/build_assert.rs:56
        ok 2 rust_doctest_kernel_build_assert_rs_1
        # rust_doctest_kernel_init_rs_0.location: rust/kernel/init.rs:122
        ok 3 rust_doctest_kernel_init_rs_0
        ...
        # rust_doctest_kernel_types_rs_2.location: rust/kernel/types.rs:150
        ok 59 rust_doctest_kernel_types_rs_2
    # rust_doctests_kernel: pass:59 fail:0 skip:0 total:59
    # Totals: pass:59 fail:0 skip:0 total:59
    ok 1 rust_doctests_kernel

Therefore, add support for running Rust documentation tests
in KUnit. Some other notes about the current implementation
and support follow.

The transformation is performed by a couple scripts written
as Rust hostprogs.

Tests using the `?` operator are also supported as usual, e.g.:

    /// ```
    /// # use kernel::{spawn_work_item, workqueue};
    /// spawn_work_item!(workqueue::system(), || pr_info!("x"))?;
    /// # Ok::<(), Error>(())
    /// ```

The tests are also compiled with Clippy under `CLIPPY=1`, just
like normal code, thus also benefitting from extra linting.

The names of the tests are currently automatically generated.
This allows to reduce the burden for documentation writers,
while keeping them fairly stable for bisection. This is an
improvement over the `rustdoc`-generated names, which include
the line number; but ideally we would like to get `rustdoc` to
provide the Rust item path and a number (for multiple examples
in a single documented Rust item).

In order for developers to easily see from which original line
a failed doctests came from, a KTAP diagnostic line is printed
to the log, containing the location (file and line) of the
original test (i.e. instead of the location in the generated
Rust file):

    # rust_doctest_kernel_types_rs_2.location: rust/kernel/types.rs:150

This line follows the syntax for declaring test metadata in the
proposed KTAP v2 spec [1], which may be used for the proposed
KUnit test attributes API [2]. Thus hopefully this will make
migration easier later on (suggested by David [3]).

The original line in that test attribute is figured out by
providing an anchor (suggested by Boqun [4]). The original file
is found by walking the filesystem, checking directory prefixes
to reduce the amount of combinations to check, and it is only
done once per file. Ambiguities are detected and reported.

A notable difference from KUnit C tests is that the Rust tests
appear to assert using the usual `assert!` and `assert_eq!`
macros from the Rust standard library (`core`). We provide
a custom version that forwards the call to KUnit instead.
Importantly, these macros do not require passing context,
unlike the KUnit C ones (i.e. `struct kunit *`). This makes
them easier to use, and readers of the documentation do not need
to care about which testing framework is used. In addition, it
may allow us to test third-party code more easily in the future.

However, a current limitation is that KUnit does not support
assertions in other tasks. Thus we presently simply print an
error to the kernel log if an assertion actually failed. This
should be revisited to properly fail the test, perhaps saving
the context somewhere else, or letting KUnit handle it.

Link: https://lore.kernel.org/lkml/20230420205734.1288498-1-rmoar@google.com/ [1]
Link: https://lore.kernel.org/linux-kselftest/20230707210947.1208717-1-rmoar@google.com/ [2]
Link: https://lore.kernel.org/rust-for-linux/CABVgOSkOLO-8v6kdAGpmYnZUb+LKOX0CtYCo-Bge7r_2YTuXDQ@mail.gmail.com/ [3]
Link: https://lore.kernel.org/rust-for-linux/ZIps86MbJF%2FiGIzd@boqun-archlinux/ [4]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2023-07-19 09:32:53 -06:00
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 <walmeida@microsoft.com>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com>
Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Link: https://lore.kernel.org/r/20230531174450.3733220-1-aliceryhl@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-06-13 01:24:42 +02:00
Wedson Almeida Filho 19096bce81 rust: sync: introduce `CondVar`
This is the traditional condition variable or monitor synchronisation
primitive. It is implemented with C's `wait_queue_head_t`.

It allows users to release a lock and go to sleep while guaranteeing
that notifications won't be missed. This is achieved by enqueuing a wait
entry before releasing the lock.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20230411054543.21278-12-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22 01:46:45 +02:00
Wedson Almeida Filho 8da7a2b743 rust: introduce `current`
This allows Rust code to get a reference to the current task without
having to increment the refcount, but still guaranteeing memory safety.

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20230411054543.21278-10-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22 00:20:00 +02:00
Wedson Almeida Filho 313c4281bc rust: add basic `Task`
It is an abstraction for C's `struct task_struct`. It implements
`AlwaysRefCounted`, so the refcount of the wrapped object is managed
safely on the Rust side.

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20230411054543.21278-9-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22 00:20:00 +02:00
Wedson Almeida Filho c6d917a498 rust: lock: introduce `SpinLock`
This is the `spinlock_t` lock backend and allows Rust code to use the
kernel spinlock idiomatically.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20230419174426.132207-1-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22 00:20:00 +02:00
Wedson Almeida Filho 6d20d629c6 rust: lock: introduce `Mutex`
This is the `struct mutex` lock backend and allows Rust code to use the
kernel mutex idiomatically.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20230411054543.21278-3-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22 00:20:00 +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 <boqun.feng@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Co-developed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Co-developed-by: Fox Chen <foxhlchen@gmail.com>
Signed-off-by: Fox Chen <foxhlchen@gmail.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Asahi Lina <lina@asahilina.net>
Link: https://lore.kernel.org/r/20230224-rust-error-v3-5-03779bddc02b@asahilina.net
[ Add a removal of `#[allow(dead_code)]`. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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 <yakoyoku@gmail.com>
Signed-off-by: Asahi Lina <lina@asahilina.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20230224-rust-error-v3-2-03779bddc02b@asahilina.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:04 +02:00
Wedson Almeida Filho 9dc0436550 rust: sync: add `Arc` for ref-counted allocations
This is a basic implementation of `Arc` backed by C's `refcount_t`. It
allows Rust code to idiomatically allocate memory that is ref-counted.

Cc: Will Deacon <will@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-01-16 22:20:03 +01:00
Miguel Ojeda 12f577216a rust: add C helpers
Introduces the source file that will contain forwarders to C macros
and inlined functions.

Initially this only contains a single helper, but will gain more as
more functionality is added to the `kernel` crate in the future.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Geoffrey Thomas <geofft@ldpreload.com>
Signed-off-by: Geoffrey Thomas <geofft@ldpreload.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com>
Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Co-developed-by: Maciej Falkowski <m.falkowski@samsung.com>
Signed-off-by: Maciej Falkowski <m.falkowski@samsung.com>
Co-developed-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28 08:56:43 +02:00