Commit Graph

154 Commits

Author SHA1 Message Date
Miguel Ojeda
17d5efcbfe rust: kernel: remove support for unused host #[test]s
Since commit 028df914e5 ("rust: str: convert `rusttest` tests into
KUnit"), we do not have anymore host `#[test]`s that run in the host.

Moreover, we do not plan to add any new ones -- tests should generally
run within KUnit, since there they are built the same way the kernel
does. While we may want to have some way to define tests that can also
be run outside the kernel, we still want to test within the kernel too
[1], and thus would likely use a custom syntax anyway to define them.

Thus simplify the `rusttest` target by removing support for host
`#[test]`s for the `kernel` crate.

This still maintains the support for the `macros` crate, even though we
do not have any such tests there.

Link: https://lore.kernel.org/rust-for-linux/CABVgOS=AKHSfifp0S68K3jgNZAkALBr=7iFb=niryG5WDxjSrg@mail.gmail.com/ [1]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/r/20250726180750.2735836-1-ojeda@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-08-24 15:29:51 +02:00
Miguel Ojeda
252fea131e rust: kbuild: clean output before running rustdoc
`rustdoc` can get confused when generating documentation into a folder
that contains generated files from other `rustdoc` versions.

For instance, running something like:

    rustup default 1.78.0
    make LLVM=1 rustdoc
    rustup default 1.88.0
    make LLVM=1 rustdoc

may generate errors like:

    error: couldn't generate documentation: invalid template: last line expected to start with a comment
      |
      = note: failed to create or modify "./Documentation/output/rust/rustdoc/src-files.js"

Thus just always clean the output folder before generating the
documentation -- we are anyway regenerating it every time the `rustdoc`
target gets called, at least for the time being.

Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Reported-by: Daniel Almeida <daniel.almeida@collabora.com>
Closes: https://rust-for-linux.zulipchat.com/#narrow/channel/288089/topic/x/near/527201113
Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Link: https://lore.kernel.org/r/20250726133435.2460085-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-08-12 21:10:50 +02:00
Miguel Ojeda
abbf9a4494 rust: workaround rustdoc target modifiers bug
Starting with Rust 1.88.0 (released 2025-06-26), `rustdoc` complains
about a target modifier mismatch in configurations where `-Zfixed-x18`
is passed:

    error: mixing `-Zfixed-x18` will cause an ABI mismatch in crate `rust_out`
      |
      = help: the `-Zfixed-x18` flag modifies the ABI so Rust crates compiled with different values of this flag cannot be used together safely
      = note: unset `-Zfixed-x18` in this crate is incompatible with `-Zfixed-x18=` in dependency `core`
      = help: set `-Zfixed-x18=` in this crate or unset `-Zfixed-x18` in `core`
      = help: if you are sure this will not cause problems, you may use `-Cunsafe-allow-abi-mismatch=fixed-x18` to silence this error

The reason is that `rustdoc` was not passing the target modifiers when
configuring the session options, and thus it would report a mismatch
that did not exist as soon as a target modifier is used in a dependency.

We did not notice it in the kernel until now because `-Zfixed-x18` has
been a target modifier only since 1.88.0 (and it is the only one we use
so far).

The issue has been reported upstream [1] and a fix has been submitted
[2], including a test similar to the kernel case.

  [ This is now fixed upstream (thanks Guillaume for the quick review),
    so it will be fixed in Rust 1.90.0 (expected 2025-09-18).

      - Miguel ]

Meanwhile, conditionally pass `-Cunsafe-allow-abi-mismatch=fixed-x18`
to workaround the issue on our side.

Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Reported-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Closes: https://lore.kernel.org/rust-for-linux/36cdc798-524f-4910-8b77-d7b9fac08d77@oss.qualcomm.com/
Link: https://github.com/rust-lang/rust/issues/144521 [1]
Link: https://github.com/rust-lang/rust/pull/144523 [2]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250727092317.2930617-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-08-12 21:06:48 +02:00
Linus Torvalds
352af6a011 Rust changes for v6.17
Toolchain and infrastructure:
 
  - Enable a set of Clippy lints: 'ptr_as_ptr', 'ptr_cast_constness',
    'as_ptr_cast_mut', 'as_underscore', 'cast_lossless' and 'ref_as_ptr'.
 
    These are intended to avoid type casts with the 'as' operator, which
    are quite powerful, into restricted variants that are less powerful
    and thus should help to avoid mistakes.
 
  - Remove the 'author' key now that most instances were moved to the
    plural one in the previous cycle.
 
 'kernel' crate:
 
  - New 'bug' module: add 'warn_on!' macro which reuses the existing
    'BUG'/'WARN' infrastructure, i.e. it respects the usual sysctls and
    kernel parameters:
 
        warn_on!(value == 42);
 
    To avoid duplicating the assembly code, the same strategy is followed
    as for the static branch code in order to share the assembly between
    both C and Rust. This required a few rearrangements on C arch headers
    -- the existing C macros should still generate the same outputs, thus
    no functional change expected there.
 
  - 'workqueue' module: add delayed work items, including a 'DelayedWork'
    struct, a 'impl_has_delayed_work!' macro and an 'enqueue_delayed'
    method, e.g.:
 
        /// Enqueue the struct for execution on the system workqueue,
        /// where its value will be printed 42 jiffies later.
        fn print_later(value: Arc<MyStruct>) {
            let _ = workqueue::system().enqueue_delayed(value, 42);
        }
 
  - New 'bits' module: add support for 'bit' and 'genmask' functions,
    with runtime- and compile-time variants, e.g.:
 
        static_assert!(0b00010000 == bit_u8(4));
        static_assert!(0b00011110 == genmask_u8(1..=4));
 
        assert!(checked_bit_u32(u32::BITS).is_none());
 
  - 'uaccess' module: add 'UserSliceReader::strcpy_into_buf', which reads
    NUL-terminated strings from userspace into a '&CStr'.
 
    Introduce 'UserPtr' newtype, similar in purpose to '__user' in C, to
    minimize mistakes handling userspace pointers, including mixing them
    up with integers and leaking them via the 'Debug' trait. Add it to
    the prelude, too.
 
  - Start preparations for the replacement of our custom 'CStr' type
    with the analogous type in the 'core' standard library. This will
    take place across several cycles to make it easier. For this one,
    it includes a new 'fmt' module, using upstream method names and some
    other cleanups.
 
    Replace 'fmt!' with a re-export, which helps Clippy lint properly,
    and clean up the found 'uninlined-format-args' instances.
 
  - 'dma' module:
 
    - Clarify wording and be consistent in 'coherent' nomenclature.
 
    - Convert the 'read!()' and 'write!()' macros to return a 'Result'.
 
    - Add 'as_slice()', 'write()' methods in 'CoherentAllocation'.
 
    - Expose 'count()' and 'size()' in 'CoherentAllocation' and add the
      corresponding type invariants.
 
    - Implement 'CoherentAllocation::dma_handle_with_offset()'.
 
  - 'time' module:
 
    - Make 'Instant' generic over clock source. This allows the compiler
      to assert that arithmetic expressions involving the 'Instant' use
      'Instants' based on the same clock source.
 
    - Make 'HrTimer' generic over the timer mode. 'HrTimer' timers take a
      'Duration' or an 'Instant' when setting the expiry time, depending
      on the timer mode. With this change, the compiler can check the
      type matches the timer mode.
 
    - Add an abstraction for 'fsleep'. 'fsleep' is a flexible sleep
      function that will select an appropriate sleep method depending on
      the requested sleep time.
 
    - Avoid 64-bit divisions on 32-bit hardware when calculating
      timestamps.
 
    - Seal the 'HrTimerMode' trait. This prevents users of the
      'HrTimerMode' from implementing the trait on their own types.
 
    - Pass the correct timer mode ID to 'hrtimer_start_range_ns()'.
 
  - 'list' module: remove 'OFFSET' constants, allowing to remove pointer
    arithmetic; now 'impl_list_item!' invokes 'impl_has_list_links!' or
    'impl_has_list_links_self_ptr!'. Other simplifications too.
 
  - 'types' module: remove 'ForeignOwnable::PointedTo' in favor of a
    constant, which avoids exposing the type of the opaque pointer, and
    require 'into_foreign' to return non-null.
 
    Remove the 'Either<L, R>' type as well. It is unused, and we want to
    encourage the use of custom enums for concrete use cases.
 
  - 'sync' module: implement 'Borrow' and 'BorrowMut' for 'Arc' types
    to allow them to be used in generic APIs.
 
  - 'alloc' module: implement 'Borrow' and 'BorrowMut' for 'Box<T, A>';
     and 'Borrow', 'BorrowMut' and 'Default' for 'Vec<T, A>'.
 
  - 'Opaque' type: add 'cast_from' method to perform a restricted cast
    that cannot change the inner type and use it in callers of
    'container_of!'. Rename 'raw_get' to 'cast_into' to match it.
 
  - 'rbtree' module: add 'is_empty' method.
 
  - 'sync' module: new 'aref' submodule to hold 'AlwaysRefCounted' and
    'ARef', which are moved from the too general 'types' module which we
    want to reduce or eventually remove. Also fix a safety comment in
    'static_lock_class'.
 
 'pin-init' crate:
 
  - Add 'impl<T, E> [Pin]Init<T, E> for Result<T, E>', so results are now
    (pin-)initializers.
 
  - Add 'Zeroable::init_zeroed()' that delegates to 'init_zeroed()'.
 
  - New 'zeroed()', a safe version of 'mem::zeroed()' and also provide
    it via 'Zeroable::zeroed()'.
 
  - Implement 'Zeroable' for 'Option<&T>', 'Option<&mut T>' and for
    'Option<[unsafe] [extern "abi"] fn(...args...) -> ret>' for '"Rust"'
    and '"C"' ABIs and up to 20 arguments.
 
  - Changed blanket impls of 'Init' and 'PinInit' from 'impl<T, E>
    [Pin]Init<T, E> for T' to 'impl<T> [Pin]Init<T> for T'.
 
  - Renamed 'zeroed()' to 'init_zeroed()'.
 
  - Upstream dev news: improve CI more to deny warnings, use
    '--all-targets'. Check the synchronization status of the two '-next'
    branches in upstream and the kernel.
 
 MAINTAINERS:
 
  - Add Vlastimil Babka, Liam R. Howlett, Uladzislau Rezki and Lorenzo
    Stoakes as reviewers (thanks everyone).
 
 And a few other cleanups and improvements.
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Merge tag 'rust-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

Pull Rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Enable a set of Clippy lints: 'ptr_as_ptr', 'ptr_cast_constness',
     'as_ptr_cast_mut', 'as_underscore', 'cast_lossless' and
     'ref_as_ptr'

     These are intended to avoid type casts with the 'as' operator,
     which are quite powerful, into restricted variants that are less
     powerful and thus should help to avoid mistakes

   - Remove the 'author' key now that most instances were moved to the
     plural one in the previous cycle

  'kernel' crate:

   - New 'bug' module: add 'warn_on!' macro which reuses the existing
     'BUG'/'WARN' infrastructure, i.e. it respects the usual sysctls and
     kernel parameters:

         warn_on!(value == 42);

     To avoid duplicating the assembly code, the same strategy is
     followed as for the static branch code in order to share the
     assembly between both C and Rust

     This required a few rearrangements on C arch headers -- the
     existing C macros should still generate the same outputs, thus no
     functional change expected there

   - 'workqueue' module: add delayed work items, including a
     'DelayedWork' struct, a 'impl_has_delayed_work!' macro and an
     'enqueue_delayed' method, e.g.:

         /// Enqueue the struct for execution on the system workqueue,
         /// where its value will be printed 42 jiffies later.
         fn print_later(value: Arc<MyStruct>) {
             let _ = workqueue::system().enqueue_delayed(value, 42);
         }

   - New 'bits' module: add support for 'bit' and 'genmask' functions,
     with runtime- and compile-time variants, e.g.:

         static_assert!(0b00010000 == bit_u8(4));
         static_assert!(0b00011110 == genmask_u8(1..=4));

         assert!(checked_bit_u32(u32::BITS).is_none());

   - 'uaccess' module: add 'UserSliceReader::strcpy_into_buf', which
     reads NUL-terminated strings from userspace into a '&CStr'

     Introduce 'UserPtr' newtype, similar in purpose to '__user' in C,
     to minimize mistakes handling userspace pointers, including mixing
     them up with integers and leaking them via the 'Debug' trait. Add
     it to the prelude, too

   - Start preparations for the replacement of our custom 'CStr' type
     with the analogous type in the 'core' standard library. This will
     take place across several cycles to make it easier. For this one,
     it includes a new 'fmt' module, using upstream method names and
     some other cleanups

     Replace 'fmt!' with a re-export, which helps Clippy lint properly,
     and clean up the found 'uninlined-format-args' instances

   - 'dma' module:

      - Clarify wording and be consistent in 'coherent' nomenclature

      - Convert the 'read!()' and 'write!()' macros to return a 'Result'

      - Add 'as_slice()', 'write()' methods in 'CoherentAllocation'

      - Expose 'count()' and 'size()' in 'CoherentAllocation' and add
        the corresponding type invariants

      - Implement 'CoherentAllocation::dma_handle_with_offset()'

   - 'time' module:

      - Make 'Instant' generic over clock source. This allows the
        compiler to assert that arithmetic expressions involving the
        'Instant' use 'Instants' based on the same clock source

      - Make 'HrTimer' generic over the timer mode. 'HrTimer' timers
        take a 'Duration' or an 'Instant' when setting the expiry time,
        depending on the timer mode. With this change, the compiler can
        check the type matches the timer mode

      - Add an abstraction for 'fsleep'. 'fsleep' is a flexible sleep
        function that will select an appropriate sleep method depending
        on the requested sleep time

      - Avoid 64-bit divisions on 32-bit hardware when calculating
        timestamps

      - Seal the 'HrTimerMode' trait. This prevents users of the
        'HrTimerMode' from implementing the trait on their own types

      - Pass the correct timer mode ID to 'hrtimer_start_range_ns()'

   - 'list' module: remove 'OFFSET' constants, allowing to remove
     pointer arithmetic; now 'impl_list_item!' invokes
     'impl_has_list_links!' or 'impl_has_list_links_self_ptr!'. Other
     simplifications too

   - 'types' module: remove 'ForeignOwnable::PointedTo' in favor of a
     constant, which avoids exposing the type of the opaque pointer, and
     require 'into_foreign' to return non-null

     Remove the 'Either<L, R>' type as well. It is unused, and we want
     to encourage the use of custom enums for concrete use cases

   - 'sync' module: implement 'Borrow' and 'BorrowMut' for 'Arc' types
     to allow them to be used in generic APIs

   - 'alloc' module: implement 'Borrow' and 'BorrowMut' for 'Box<T, A>';
     and 'Borrow', 'BorrowMut' and 'Default' for 'Vec<T, A>'

   - 'Opaque' type: add 'cast_from' method to perform a restricted cast
     that cannot change the inner type and use it in callers of
     'container_of!'. Rename 'raw_get' to 'cast_into' to match it

   - 'rbtree' module: add 'is_empty' method

   - 'sync' module: new 'aref' submodule to hold 'AlwaysRefCounted' and
     'ARef', which are moved from the too general 'types' module which
     we want to reduce or eventually remove. Also fix a safety comment
     in 'static_lock_class'

  'pin-init' crate:

   - Add 'impl<T, E> [Pin]Init<T, E> for Result<T, E>', so results are
     now (pin-)initializers

   - Add 'Zeroable::init_zeroed()' that delegates to 'init_zeroed()'

   - New 'zeroed()', a safe version of 'mem::zeroed()' and also provide
     it via 'Zeroable::zeroed()'

   - Implement 'Zeroable' for 'Option<&T>', 'Option<&mut T>' and for
     'Option<[unsafe] [extern "abi"] fn(...args...) -> ret>' for
     '"Rust"' and '"C"' ABIs and up to 20 arguments

   - Changed blanket impls of 'Init' and 'PinInit' from 'impl<T, E>
     [Pin]Init<T, E> for T' to 'impl<T> [Pin]Init<T> for T'

   - Renamed 'zeroed()' to 'init_zeroed()'

   - Upstream dev news: improve CI more to deny warnings, use
     '--all-targets'. Check the synchronization status of the two
     '-next' branches in upstream and the kernel

  MAINTAINERS:

   - Add Vlastimil Babka, Liam R. Howlett, Uladzislau Rezki and Lorenzo
     Stoakes as reviewers (thanks everyone)

  And a few other cleanups and improvements"

* tag 'rust-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (76 commits)
  rust: Add warn_on macro
  arm64/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
  riscv/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
  x86/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
  rust: kernel: move ARef and AlwaysRefCounted to sync::aref
  rust: sync: fix safety comment for `static_lock_class`
  rust: types: remove `Either<L, R>`
  rust: kernel: use `core::ffi::CStr` method names
  rust: str: add `CStr` methods matching `core::ffi::CStr`
  rust: str: remove unnecessary qualification
  rust: use `kernel::{fmt,prelude::fmt!}`
  rust: kernel: add `fmt` module
  rust: kernel: remove `fmt!`, fix clippy::uninlined-format-args
  scripts: rust: emit path candidates in panic message
  scripts: rust: replace length checks with match
  rust: list: remove nonexistent generic parameter in link
  rust: bits: add support for bits/genmask macros
  rust: list: remove OFFSET constants
  rust: list: add `impl_list_item!` examples
  rust: list: use fully qualified path
  ...
2025-08-03 13:49:10 -07:00
FUJITA Tomonori
dff64b0727 rust: Add warn_on macro
Add warn_on macro, uses the BUG/WARN feature (lib/bug.c) via assembly
for x86_64/arm64/riscv.

The current Rust code simply wraps BUG() macro but doesn't provide the
proper debug information. The BUG/WARN feature can only be used from
assembly.

This uses the assembly code exported by the C side via ARCH_WARN_ASM
macro. To avoid duplicating the assembly code, this approach follows
the same strategy as the static branch code: it generates the assembly
code for Rust using the C preprocessor at compile time.

Similarly, ARCH_WARN_REACHABLE is also used at compile time to
generate the assembly code; objtool's reachable annotation code. It's
used for only architectures that use objtool.

For now, Loongarch and arm just use a wrapper for WARN macro.

UML doesn't use the assembly BUG/WARN feature; just wrapping generic
BUG/WARN functions implemented in C works.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250502094537.231725-5-fujita.tomonori@gmail.com
[ Avoid evaluating the condition twice (a good idea in general,
  but it also matches the C side). Simplify with `as_char_ptr()`
  to avoid a cast. Cast to `ffi` integer types for
  `warn_slowpath_fmt`. Avoid cast for `null()`. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-23 02:05:58 +02:00
Miguel Ojeda
7498159226 rust: use #[used(compiler)] to fix build and modpost with Rust >= 1.89.0
Starting with Rust 1.89.0 (expected 2025-08-07), the Rust compiler fails
to build the `rusttest` target due to undefined references such as:

    kernel...-cgu.0:(.text....+0x116): undefined reference to
    `rust_helper_kunit_get_current_test'

Moreover, tooling like `modpost` gets confused:

    WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/gpu/drm/nova/nova.o
    ERROR: modpost: missing MODULE_LICENSE() in drivers/gpu/nova-core/nova_core.o

The reason behind both issues is that the Rust compiler will now [1]
treat `#[used]` as `#[used(linker)]` instead of `#[used(compiler)]`
for our targets. This means that the retain section flag (`R`,
`SHF_GNU_RETAIN`) will be used and that they will be marked as `unique`
too, with different IDs. In turn, that means we end up with undefined
references that did not get discarded in `rusttest` and that multiple
`.modinfo` sections are generated, which confuse tooling like `modpost`
because they only expect one.

Thus start using `#[used(compiler)]` to keep the previous behavior
and to be explicit about what we want. Sadly, it is an unstable feature
(`used_with_arg`) [2] -- we will talk to upstream Rust about it. The good
news is that it has been available for a long time (Rust >= 1.60) [3].

The changes should also be fine for previous Rust versions, since they
behave the same way as before [4].

Alternatively, we could use `#[no_mangle]` or `#[export_name = ...]`
since those still behave like `#[used(compiler)]`, but of course it is
not really what we want to express, and it requires other changes to
avoid symbol conflicts.

Cc: David Wood <david@davidtw.co>
Cc: Wesley Wiser <wwiser@gmail.com>
Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: https://github.com/rust-lang/rust/pull/140872 [1]
Link: https://github.com/rust-lang/rust/issues/93798 [2]
Link: https://github.com/rust-lang/rust/pull/91504 [3]
Link: https://godbolt.org/z/sxzWTMfzW [4]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Link: https://lore.kernel.org/r/20250712160103.1244945-3-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-14 23:30:44 +02:00
Linus Torvalds
ec7714e494 Rust changes for v6.16
Toolchain and infrastructure:
 
  - KUnit '#[test]'s:
 
    - Support KUnit-mapped 'assert!' macros.
 
      The support that landed last cycle was very basic, and the
      'assert!' macros panicked since they were the standard library
      ones. Now, they are mapped to the KUnit ones in a similar way to
      how is done for doctests, reusing the infrastructure there.
 
      With this, a failing test like:
 
          #[test]
          fn my_first_test() {
              assert_eq!(42, 43);
          }
 
      will report:
 
          # my_first_test: ASSERTION FAILED at rust/kernel/lib.rs:251
          Expected 42 == 43 to be true, but is false
          # my_first_test.speed: normal
          not ok 1 my_first_test
 
    - Support tests with checked 'Result' return types.
 
      The return value of test functions that return a 'Result' will be
      checked, thus one can now easily catch errors when e.g. using the
      '?' operator in tests.
 
      With this, a failing test like:
 
          #[test]
          fn my_test() -> Result {
              f()?;
              Ok(())
          }
 
      will report:
 
          # my_test: ASSERTION FAILED at rust/kernel/lib.rs:321
          Expected is_test_result_ok(my_test()) to be true, but is false
          # my_test.speed: normal
          not ok 1 my_test
 
    - Add 'kunit_tests' to the prelude.
 
  - Clarify the remaining language unstable features in use.
 
  - Compile 'core' with edition 2024 for Rust >= 1.87.
 
  - Workaround 'bindgen' issue with forward references to 'enum' types.
 
  - objtool: relax slice condition to cover more 'noreturn' functions.
 
  - Use absolute paths in macros referencing 'core' and 'kernel' crates.
 
  - Skip '-mno-fdpic' flag for bindgen in GCC 32-bit arm builds.
 
  - Clean some 'doc_markdown' lint hits -- we may enable it later on.
 
 'kernel' crate:
 
  - 'alloc' module:
 
    - 'Box': support for type coercion, e.g. 'Box<T>' to 'Box<dyn U>' if
      'T' implements 'U'.
 
    - 'Vec': implement new methods (prerequisites for nova-core and
      binder): 'truncate', 'resize', 'clear', 'pop',
      'push_within_capacity' (with new error type 'PushError'),
      'drain_all', 'retain', 'remove' (with new error type
      'RemoveError'), insert_within_capacity' (with new error type
      'InsertError').
 
      In addition, simplify 'push' using 'spare_capacity_mut', split
      'set_len' into 'inc_len' and 'dec_len', add type invariant
      'len <= capacity' and simplify 'truncate' using 'dec_len'.
 
  - 'time' module:
 
    - Morph the Rust hrtimer subsystem into the Rust timekeeping
      subsystem, covering delay, sleep, timekeeping, timers. This new
      subsystem has all the relevant timekeeping C maintainers listed in
      the entry.
 
    - Replace 'Ktime' with 'Delta' and 'Instant' types to represent a
      duration of time and a point in time.
 
    - Temporarily add 'Ktime' to 'hrtimer' module to allow 'hrtimer' to
      delay converting to 'Instant' and 'Delta'.
 
  - 'xarray' module:
 
    - Add a Rust abstraction for the 'xarray' data structure. This
      abstraction allows Rust code to leverage the 'xarray' to store
      types that implement 'ForeignOwnable'. This support is a dependency
      for memory backing feature of the Rust null block driver, which is
      waiting to be merged.
 
    - Set up an entry in 'MAINTAINERS' for the XArray Rust support.
      Patches will go to the new Rust XArray tree and then via the Rust
      subsystem tree for now.
 
    - Allow 'ForeignOwnable' to carry information about the pointed-to
      type. This helps asserting alignment requirements for the pointer
      passed to the foreign language.
 
  - 'container_of!': retain pointer mut-ness and add a compile-time check
    of the type of the first parameter ('$field_ptr').
 
  - Support optional message in 'static_assert!'.
 
  - Add C FFI types (e.g. 'c_int') to the prelude.
 
  - 'str' module: simplify KUnit tests 'format!' macro, convert
    'rusttest' tests into KUnit, take advantage of the '-> Result'
    support in KUnit '#[test]'s.
 
  - 'list' module: add examples for 'List', fix path of 'assert_pinned!'
    (so far unused macro rule).
 
  - 'workqueue' module: remove 'HasWork::OFFSET'.
 
  - 'page' module: add 'inline' attribute.
 
 'macros' crate:
 
  - 'module' macro: place 'cleanup_module()' in '.exit.text' section.
 
 'pin-init' crate:
 
  - Add 'Wrapper<T>' trait for creating pin-initializers for wrapper
    structs with a structurally pinned value such as 'UnsafeCell<T>' or
    'MaybeUninit<T>'.
 
  - Add 'MaybeZeroable' derive macro to try to derive 'Zeroable', but
    not error if not all fields implement it. This is needed to derive
    'Zeroable' for all bindgen-generated structs.
 
  - Add 'unsafe fn cast_[pin_]init()' functions to unsafely change the
    initialized type of an initializer. These are utilized by the
    'Wrapper<T>' implementations.
 
  - Add support for visibility in 'Zeroable' derive macro.
 
  - Add support for 'union's in 'Zeroable' derive macro.
 
  - Upstream dev news: streamline CI, fix some bugs. Add new workflows
    to check if the user-space version and the one in the kernel tree
    have diverged. Use the issues tab [1] to track them, which should
    help folks report and diagnose issues w.r.t. 'pin-init' better.
 
      [1] https://github.com/rust-for-linux/pin-init/issues
 
 Documentation:
 
  - Testing: add docs on the new KUnit '#[test]' tests.
 
  - Coding guidelines: explain that '///' vs. '//' applies to private
    items too. Add section on C FFI types.
 
  - Quick Start guide: update Ubuntu instructions and split them into
    "25.04" and "24.04 LTS and older".
 
 And a few other cleanups and improvements.
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Merge tag 'rust-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

Pull Rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - KUnit '#[test]'s:

      - Support KUnit-mapped 'assert!' macros.

        The support that landed last cycle was very basic, and the
        'assert!' macros panicked since they were the standard library
        ones. Now, they are mapped to the KUnit ones in a similar way to
        how is done for doctests, reusing the infrastructure there.

        With this, a failing test like:

            #[test]
            fn my_first_test() {
                assert_eq!(42, 43);
            }

        will report:

            # my_first_test: ASSERTION FAILED at rust/kernel/lib.rs:251
            Expected 42 == 43 to be true, but is false
            # my_first_test.speed: normal
            not ok 1 my_first_test

      - Support tests with checked 'Result' return types.

        The return value of test functions that return a 'Result' will
        be checked, thus one can now easily catch errors when e.g. using
        the '?' operator in tests.

        With this, a failing test like:

            #[test]
            fn my_test() -> Result {
                f()?;
                Ok(())
            }

        will report:

            # my_test: ASSERTION FAILED at rust/kernel/lib.rs:321
            Expected is_test_result_ok(my_test()) to be true, but is false
            # my_test.speed: normal
            not ok 1 my_test

      - Add 'kunit_tests' to the prelude.

   - Clarify the remaining language unstable features in use.

   - Compile 'core' with edition 2024 for Rust >= 1.87.

   - Workaround 'bindgen' issue with forward references to 'enum' types.

   - objtool: relax slice condition to cover more 'noreturn' functions.

   - Use absolute paths in macros referencing 'core' and 'kernel'
     crates.

   - Skip '-mno-fdpic' flag for bindgen in GCC 32-bit arm builds.

   - Clean some 'doc_markdown' lint hits -- we may enable it later on.

  'kernel' crate:

   - 'alloc' module:

      - 'Box': support for type coercion, e.g. 'Box<T>' to 'Box<dyn U>'
        if 'T' implements 'U'.

      - 'Vec': implement new methods (prerequisites for nova-core and
        binder): 'truncate', 'resize', 'clear', 'pop',
        'push_within_capacity' (with new error type 'PushError'),
        'drain_all', 'retain', 'remove' (with new error type
        'RemoveError'), insert_within_capacity' (with new error type
        'InsertError').

        In addition, simplify 'push' using 'spare_capacity_mut', split
        'set_len' into 'inc_len' and 'dec_len', add type invariant 'len
        <= capacity' and simplify 'truncate' using 'dec_len'.

   - 'time' module:

      - Morph the Rust hrtimer subsystem into the Rust timekeeping
        subsystem, covering delay, sleep, timekeeping, timers. This new
        subsystem has all the relevant timekeeping C maintainers listed
        in the entry.

      - Replace 'Ktime' with 'Delta' and 'Instant' types to represent a
        duration of time and a point in time.

      - Temporarily add 'Ktime' to 'hrtimer' module to allow 'hrtimer'
        to delay converting to 'Instant' and 'Delta'.

   - 'xarray' module:

      - Add a Rust abstraction for the 'xarray' data structure. This
        abstraction allows Rust code to leverage the 'xarray' to store
        types that implement 'ForeignOwnable'. This support is a
        dependency for memory backing feature of the Rust null block
        driver, which is waiting to be merged.

      - Set up an entry in 'MAINTAINERS' for the XArray Rust support.
        Patches will go to the new Rust XArray tree and then via the
        Rust subsystem tree for now.

      - Allow 'ForeignOwnable' to carry information about the pointed-to
        type. This helps asserting alignment requirements for the
        pointer passed to the foreign language.

   - 'container_of!': retain pointer mut-ness and add a compile-time
     check of the type of the first parameter ('$field_ptr').

   - Support optional message in 'static_assert!'.

   - Add C FFI types (e.g. 'c_int') to the prelude.

   - 'str' module: simplify KUnit tests 'format!' macro, convert
     'rusttest' tests into KUnit, take advantage of the '-> Result'
     support in KUnit '#[test]'s.

   - 'list' module: add examples for 'List', fix path of
     'assert_pinned!' (so far unused macro rule).

   - 'workqueue' module: remove 'HasWork::OFFSET'.

   - 'page' module: add 'inline' attribute.

  'macros' crate:

   - 'module' macro: place 'cleanup_module()' in '.exit.text' section.

  'pin-init' crate:

   - Add 'Wrapper<T>' trait for creating pin-initializers for wrapper
     structs with a structurally pinned value such as 'UnsafeCell<T>' or
     'MaybeUninit<T>'.

   - Add 'MaybeZeroable' derive macro to try to derive 'Zeroable', but
     not error if not all fields implement it. This is needed to derive
     'Zeroable' for all bindgen-generated structs.

   - Add 'unsafe fn cast_[pin_]init()' functions to unsafely change the
     initialized type of an initializer. These are utilized by the
     'Wrapper<T>' implementations.

   - Add support for visibility in 'Zeroable' derive macro.

   - Add support for 'union's in 'Zeroable' derive macro.

   - Upstream dev news: streamline CI, fix some bugs. Add new workflows
     to check if the user-space version and the one in the kernel tree
     have diverged. Use the issues tab [1] to track them, which should
     help folks report and diagnose issues w.r.t. 'pin-init' better.

       [1] https://github.com/rust-for-linux/pin-init/issues

  Documentation:

   - Testing: add docs on the new KUnit '#[test]' tests.

   - Coding guidelines: explain that '///' vs. '//' applies to private
     items too. Add section on C FFI types.

   - Quick Start guide: update Ubuntu instructions and split them into
     "25.04" and "24.04 LTS and older".

  And a few other cleanups and improvements"

* tag 'rust-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (78 commits)
  rust: list: Fix typo `much` in arc.rs
  rust: check type of `$ptr` in `container_of!`
  rust: workqueue: remove HasWork::OFFSET
  rust: retain pointer mut-ness in `container_of!`
  Documentation: rust: testing: add docs on the new KUnit `#[test]` tests
  Documentation: rust: rename `#[test]`s to "`rusttest` host tests"
  rust: str: take advantage of the `-> Result` support in KUnit `#[test]`'s
  rust: str: simplify KUnit tests `format!` macro
  rust: str: convert `rusttest` tests into KUnit
  rust: add `kunit_tests` to the prelude
  rust: kunit: support checked `-> Result`s in KUnit `#[test]`s
  rust: kunit: support KUnit-mapped `assert!` macros in `#[test]`s
  rust: make section names plural
  rust: list: fix path of `assert_pinned!`
  rust: compile libcore with edition 2024 for 1.87+
  rust: dma: add missing Markdown code span
  rust: task: add missing Markdown code spans and intra-doc links
  rust: pci: fix docs related to missing Markdown code spans
  rust: alloc: add missing Markdown code span
  rust: alloc: add missing Markdown code spans
  ...
2025-06-04 21:18:37 -07:00
Alice Ryhl
3bf67171e9 kcov: rust: add flags for KCOV with Rust
Rust code is currently not instrumented properly when KCOV is enabled.
Thus, add the relevant flags to perform instrumentation correctly. This
is necessary for efficient fuzzing of Rust code.

The sanitizer-coverage features of LLVM have existed for long enough
that they are available on any LLVM version supported by rustc, so we do
not need any Kconfig feature detection. The coverage level is set to 3,
as that is the level needed by trace-pc.

We do not instrument `core` since when we fuzz the kernel, we are
looking for bugs in the kernel, not the Rust stdlib.

Link: https://lkml.kernel.org/r/20250501-rust-kcov-v2-1-b71e83e9779f@google.com
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Co-developed-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Aleksandr Nogikh <nogikh@google.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: Bill Wendling <morbo@google.com>
Cc: Björn Roy Baron <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Gary Guo <gary@garyguo.net>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Trevor Gross <tmgross@umich.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31 22:46:12 -07:00
Miguel Ojeda
36174d16f3 rust: kunit: support KUnit-mapped assert! macros in #[test]s
The KUnit `#[test]` support that landed recently is very basic and does
not map the `assert*!` macros into KUnit like the doctests do, so they
panic at the moment.

Thus implement the custom mapping in a similar way to doctests, reusing
the infrastructure there.

In Rust 1.88.0, the `file()` method in `Span` may be stable [1]. However,
it was changed recently (from `SourceFile`), so we need to do something
different in previous versions. Thus create a helper for it and use it
to get the path.

With this, a failing test suite like:

    #[kunit_tests(my_test_suite)]
    mod tests {
        use super::*;

        #[test]
        fn my_first_test() {
            assert_eq!(42, 43);
        }

        #[test]
        fn my_second_test() {
            assert!(42 >= 43);
        }
    }

will properly map back to KUnit, printing something like:

    [    1.924325]     KTAP version 1
    [    1.924421]     # Subtest: my_test_suite
    [    1.924506]     # speed: normal
    [    1.924525]     1..2
    [    1.926385]     # my_first_test: ASSERTION FAILED at rust/kernel/lib.rs:251
    [    1.926385]     Expected 42 == 43 to be true, but is false
    [    1.928026]     # my_first_test.speed: normal
    [    1.928075]     not ok 1 my_first_test
    [    1.928723]     # my_second_test: ASSERTION FAILED at rust/kernel/lib.rs:256
    [    1.928723]     Expected 42 >= 43 to be true, but is false
    [    1.929834]     # my_second_test.speed: normal
    [    1.929868]     not ok 2 my_second_test
    [    1.930032] # my_test_suite: pass:0 fail:2 skip:0 total:2
    [    1.930153] # Totals: pass:0 fail:2 skip:0 total

Link: https://github.com/rust-lang/rust/pull/140514 [1]
Reviewed-by: David Gow <davidgow@google.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250502215133.1923676-2-ojeda@kernel.org
[ Required `KUNIT=y` like for doctests. Used the `cfg_attr` from the
  TODO comment and clarified its comment now that the stabilization is
  in beta and thus quite likely stable in Rust 1.88.0. Simplified the
  `new_body` code by introducing a new variable. Added
  `#[allow(clippy::incompatible_msrv)]`. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-05-27 20:07:09 +02:00
Gary Guo
f4daa80d6b rust: compile libcore with edition 2024 for 1.87+
Rust 1.87 (released on 2025-05-15) compiles core library with edition
2024 instead of 2021 [1]. Ensure that the edition matches libcore's
expectation to avoid potential breakage.

[ J3m3 reported in Zulip [2] that the `rust-analyzer` target was
  broken after this patch -- indeed, we need to avoid `core-cfgs`
  since those are passed to the `rust-analyzer` target.

  So, instead, I tweaked the patch to create a new `core-edition`
  variable and explicitly mention the `--edition` flag instead of
  reusing `core-cfg`s.

  In addition, pass a new argument using this new variable to
  `generate_rust_analyzer.py` so that we set the right edition there.

  By the way, for future reference: the `filter-out` change is needed
  for Rust < 1.87, since otherwise we would skip the `--edition=2021`
  we just added, ending up with no edition flag, and thus the compiler
  would default to the 2015 one.

  [2] https://rust-for-linux.zulipchat.com/#narrow/channel/291565/topic/x/near/520206547

    - Miguel ]

Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: https://github.com/rust-lang/rust/pull/138162 [1]
Reported-by: est31 <est31@protonmail.com>
Closes: https://github.com/Rust-for-Linux/linux/issues/1163
Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20250517085600.2857460-1-gary@garyguo.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-05-25 22:59:47 +02:00
Rudraksha Gupta
977c4308ee rust: arm: fix unknown (to Clang) argument '-mno-fdpic'
Currently rust on arm fails to compile due to '-mno-fdpic'. This flag
disables a GCC feature that we don't want for kernel builds, so let's
skip it as it doesn't apply to Clang.

    UPD     include/generated/asm-offsets.h
    CALL    scripts/checksyscalls.sh
    RUSTC L rust/core.o
    BINDGEN rust/bindings/bindings_generated.rs
    BINDGEN rust/bindings/bindings_helpers_generated.rs
    CC      rust/helpers/helpers.o
    Unable to generate bindings: clang diagnosed error: error: unknown argument: '-mno-fdpic'
    make[2]: *** [rust/Makefile:369: rust/bindings/bindings_helpers_generated.rs] Error 1
    make[2]: *** Deleting file 'rust/bindings/bindings_helpers_generated.rs'
    make[2]: *** Waiting for unfinished jobs....
    Unable to generate bindings: clang diagnosed error: error: unknown argument: '-mno-fdpic'
    make[2]: *** [rust/Makefile:349: rust/bindings/bindings_generated.rs] Error 1
    make[2]: *** Deleting file 'rust/bindings/bindings_generated.rs'
    make[1]: *** [/home/pmos/build/src/linux-next-next-20250521/Makefile:1285: prepare] Error 2
    make: *** [Makefile:248: __sub-make] Error 2

[ Naresh provided the draft diff [1].

  Ben explained [2]:

    FDPIC is only relevant with no-MMU targets, and then only for userspace.
    When configured for the arm-*-uclinuxfdpiceabi target, GCC enables FDPIC
    by default to facilitate compiling userspace programs. FDPIC is never
    used for the kernel, and we pass -mno-fdpic when building the kernel to
    override the default and make sure FDPIC is disabled.

  and [3]:

    -mno-fdpic disables a GCC feature that we don't want for kernel builds.
    clang does not support this feature, so it always behaves as though
    -mno-fdpic is passed. Therefore, it should be fine to mix the two, at
    least as far as FDPIC is concerned.

  [1] https://lore.kernel.org/rust-for-linux/CA+G9fYt4otQK4pHv8pJBW9e28yHSGCDncKquwuJiJ_1ou0pq0w@mail.gmail.com/
  [2] https://lore.kernel.org/rust-for-linux/aAKrq2InExQk7f_k@dell-precision-5540/
  [3] https://lore.kernel.org/rust-for-linux/aAo_F_UP1Gd4jHlZ@dell-precision-5540/

    - Miguel ]

Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Closes: https://lore.kernel.org/all/CA+G9fYvOanQBYXKSg7C6EU30k8sTRC0JRPJXYu7wWK51w38QUQ@mail.gmail.com/
Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Rudraksha Gupta <guptarud@gmail.com>
Link: https://lore.kernel.org/r/20250522-rust-mno-fdpic-arm-fix-v2-1-a6f691d9c198@gmail.com
[ Reworded title. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-05-23 00:10:52 +02:00
Sami Tolvanen
c59026c057 rust: kbuild: Don't export __pfx symbols
With CONFIG_PREFIX_SYMBOLS, objtool adds __pfx prefix symbols
to claim the compiler emitted call padding bytes. When
CONFIG_X86_KERNEL_IBT is not selected, the symbols are added to
individual object files and for Rust objects, they end up being
exported, resulting in warnings with CONFIG_GENDWARFKSYMS as the
symbols have no debugging information:

warning: gendwarfksyms: symbol_print_versions: no information for symbol __pfx_rust_helper_put_task_struct
warning: gendwarfksyms: symbol_print_versions: no information for symbol __pfx_rust_helper_task_euid
warning: gendwarfksyms: symbol_print_versions: no information for symbol __pfx_rust_helper_readq_relaxed
...

Filter out the __pfx prefix from exported symbols similarly to
the existing __cfi and __odr_asan prefixes.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Cc: stable@vger.kernel.org
Fixes: ac61506bf2 ("rust: Use gendwarfksyms + extended modversions for CONFIG_MODVERSIONS")
Link: https://lore.kernel.org/r/20250318231815.917621-2-samitolvanen@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-04-08 21:44:20 +02:00
Linus Torvalds
f4d2ef4825 Kbuild updates for v6.15
- Improve performance in gendwarfksyms
 
  - Remove deprecated EXTRA_*FLAGS and KBUILD_ENABLE_EXTRA_GCC_CHECKS
 
  - Support CONFIG_HEADERS_INSTALL for ARCH=um
 
  - Use more relative paths to sources files for better reproducibility
 
  - Support the loong64 Debian architecture
 
  - Add Kbuild bash completion
 
  - Introduce intermediate vmlinux.unstripped for architectures that need
    static relocations to be stripped from the final vmlinux
 
  - Fix versioning in Debian packages for -rc releases
 
  - Treat missing MODULE_DESCRIPTION() as an error
 
  - Convert Nios2 Makefiles to use the generic rule for built-in DTB
 
  - Add debuginfo support to the RPM package
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Merge tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Improve performance in gendwarfksyms

 - Remove deprecated EXTRA_*FLAGS and KBUILD_ENABLE_EXTRA_GCC_CHECKS

 - Support CONFIG_HEADERS_INSTALL for ARCH=um

 - Use more relative paths to sources files for better reproducibility

 - Support the loong64 Debian architecture

 - Add Kbuild bash completion

 - Introduce intermediate vmlinux.unstripped for architectures that need
   static relocations to be stripped from the final vmlinux

 - Fix versioning in Debian packages for -rc releases

 - Treat missing MODULE_DESCRIPTION() as an error

 - Convert Nios2 Makefiles to use the generic rule for built-in DTB

 - Add debuginfo support to the RPM package

* tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (40 commits)
  kbuild: rpm-pkg: build a debuginfo RPM
  kconfig: merge_config: use an empty file as initfile
  nios2: migrate to the generic rule for built-in DTB
  rust: kbuild: skip `--remap-path-prefix` for `rustdoc`
  kbuild: pacman-pkg: hardcode module installation path
  kbuild: deb-pkg: don't set KBUILD_BUILD_VERSION unconditionally
  modpost: require a MODULE_DESCRIPTION()
  kbuild: make all file references relative to source root
  x86: drop unnecessary prefix map configuration
  kbuild: deb-pkg: add comment about future removal of KDEB_COMPRESS
  kbuild: Add a help message for "headers"
  kbuild: deb-pkg: remove "version" variable in mkdebian
  kbuild: deb-pkg: fix versioning for -rc releases
  Documentation/kbuild: Fix indentation in modules.rst example
  x86: Get rid of Makefile.postlink
  kbuild: Create intermediate vmlinux build with relocations preserved
  kbuild: Introduce Kconfig symbol for linking vmlinux with relocations
  kbuild: link-vmlinux.sh: Make output file name configurable
  kbuild: do not generate .tmp_vmlinux*.map when CONFIG_VMLINUX_MAP=y
  Revert "kheaders: Ignore silly-rename files"
  ...
2025-04-05 15:46:50 -07:00
Linus Torvalds
e8b4712852 ARM and clkdev updates for 6.15-rc1
- Simplify ARM_MMU_KEEP usage
 - Add Rust support for ARM architecture version 7
 - Align IPIs reported in /proc/interrupts
 - require linker to support KEEP within OVERLAY
 - add KEEP() for ARM vectors
 - add __printf() attribute for clkdev functions
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux

Pull ARM and clkdev updates from Russell King:

 - Simplify ARM_MMU_KEEP usage

 - Add Rust support for ARM architecture version 7

 - Align IPIs reported in /proc/interrupts

 - require linker to support KEEP within OVERLAY

 - add KEEP() for ARM vectors

 - add __printf() attribute for clkdev functions

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux:
  ARM: 9445/1: clkdev: Mark some functions with __printf() attribute
  ARM: 9444/1: add KEEP() keyword to ARM_VECTORS
  ARM: 9443/1: Require linker to support KEEP within OVERLAY for DCE
  ARM: 9442/1: smp: Fix IPI alignment in /proc/interrupts
  ARM: 9441/1: rust: Enable Rust support for ARMv7
  ARM: 9439/1: arm32: simplify ARM_MMU_KEEP usage
2025-04-03 12:21:44 -07:00
Linus Torvalds
1c241cba19 LoongArch changes for v6.15
1, Add jump table support for objtool;
 2, Always select HAVE_VIRT_CPU_ACCOUNTING_GEN;
 3, Enable UBSAN (Undefined Behavior Sanitizer);
 4, Increase MAX_IO_PICS up to 8;
 5, Increase ARCH_DMA_MINALIGN up to 16;
 6, Fix and improve BPF JIT;
 7, Fix and improve vDSO implementation;
 8, Update the default config file;
 9, Some bug fixes and other small changes.
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Merge tag 'loongarch-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

Pull LoongArch updates from Huacai Chen:

 - Always select HAVE_VIRT_CPU_ACCOUNTING_GEN

 - Enable UBSAN (Undefined Behavior Sanitizer)

 - Increase MAX_IO_PICS up to 8

 - Increase ARCH_DMA_MINALIGN up to 16

 - Fix and improve BPF JIT

 - Fix and improve vDSO implementation

 - Update the default config file

 - Some bug fixes and other small changes

* tag 'loongarch-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: Update Loongson-3 default config file
  LoongArch: vDSO: Make use of the t8 register for vgetrandom-chacha
  LoongArch: vDSO: Remove --hash-style=sysv
  LoongArch: BPF: Don't override subprog's return value
  LoongArch: BPF: Use move_addr() for BPF_PSEUDO_FUNC
  LoongArch: BPF: Fix off-by-one error in build_prologue()
  LoongArch: Rework the arch_kgdb_breakpoint() implementation
  LoongArch: Fix device node refcount leak in fdt_cpu_clk_init()
  LoongArch: Increase ARCH_DMA_MINALIGN up to 16
  LoongArch: Increase MAX_IO_PICS up to 8
  LoongArch: Fix help text of CMDLINE_EXTEND in Kconfig
  LoongArch: Enable UBSAN (Undefined Behavior Sanitizer)
  LoongArch: Always select HAVE_VIRT_CPU_ACCOUNTING_GEN
  rust: Fix enabling Rust and building with GCC for LoongArch
2025-04-02 12:15:01 -07:00
WANG Rui
13c23cb4ed rust: Fix enabling Rust and building with GCC for LoongArch
This patch fixes a build issue on LoongArch when Rust is enabled and
compiled with GCC by explicitly setting the bindgen target and skipping
C flags that Clang doesn't support.

Cc: stable@vger.kernel.org
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-03-30 16:30:20 +08:00
Christian Schrrefl
ccb8ce5268 ARM: 9441/1: rust: Enable Rust support for ARMv7
This commit allows building ARMv7 kernels with Rust support.

The rust core library expects some __eabi_... functions
that are not implemented in the kernel.
Those functions are some float operations and __aeabi_uldivmod.
For now those are implemented with define_panicking_intrinsics!.

This is based on the code by Sven Van Asbroeck from the original
rust branch and inspired by the AArch version by Jamie Cunliffe.

I have tested the rust samples and a custom simple MMIO module
on hardware (De1SoC FPGA + Arm A9 CPU).

Tested-by: Rudraksha Gupta <guptarud@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Christian Schrefl <chrisi.schrefl@gmail.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2025-03-26 13:31:16 +00:00
Miguel Ojeda
2c8725c1dc rust: kbuild: skip --remap-path-prefix for rustdoc
`rustdoc` only recognizes `--remap-path-prefix` starting with
Rust 1.81.0, which is later than on minimum, so we cannot pass it
unconditionally. Otherwise, we get:

    error: Unrecognized option: 'remap-path-prefix'

Note that `rustc` (the compiler) does recognize the flag since a long
time ago (1.26.0).

Moreover, `rustdoc` since Rust 1.82.0 ICEs in out-of-tree builds when
using `--remap-path-prefix`. The issue has been reduced and reported
upstream [1].

Thus workaround both issues by simply skipping the flag when generating
the docs -- it is not critical there anyway.

The ICE does not reproduce under `--test`, but we still need to skip
the flag as well for `RUSTDOC TK` since it is not recognized.

Fixes: dbdffaf50f ("kbuild, rust: use -fremap-path-prefix to make paths relative")
Link: https://github.com/rust-lang/rust/issues/138520 [1]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-03-23 00:56:13 +09:00
Thomas Weißschuh
6b2dab17d6 rust: pass correct target to bindgen on Usermode Linux
Usermode Linux uses "um" as primary architecture name and the underlying
physical architecture is provided in "SUBARCH".

Resolve the target architecture flags through that underlying
architecture.

This is the same pattern as used by scripts/Makefile.clang from which
the bindgen flags are derived.

[ David says:

      (...) this is enough to get Rust-for-Linux working with gcc under
      64-bit UML on my system.

    - Miguel ]

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: David Gow <davidgow@googl.ecom>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Link: https://lore.kernel.org/r/20250208-rust-kunit-v1-1-94a026be6d72@weissschuh.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-19 23:18:34 +01:00
Benno Lossin
9b2299af3b rust: pin-init: add std and alloc support from the user-space version
To synchronize the kernel's version of pin-init with the user-space
version, introduce support for `std` and `alloc`. While the kernel uses
neither, the user-space version has to support both. Thus include the
required `#[cfg]`s and additional code.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-17-benno.lossin@proton.me
[ Undo the temporary `--extern force:alloc` since now we have contents
  for `alloc` here. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-16 21:59:19 +01:00
Benno Lossin
dbd5058ba6 rust: make pin-init its own crate
Rename relative paths inside of the crate to still refer to the same
items, also rename paths inside of the kernel crate and adjust the build
system to build the crate.

[ Remove the `expect` (and thus the `lint_reasons` feature) since
  the tree now uses `quote!` from `rust/macros/export.rs`. Remove the
  `TokenStream` import removal, since it is now used as well.

  In addition, temporarily (i.e. just for this commit) use an `--extern
  force:alloc` to prevent an unknown `new_uninit` error in the `rustdoc`
  target. For context, please see a similar case in:

      https://lore.kernel.org/lkml/20240422090644.525520-1-ojeda@kernel.org/

  And adjusted the message above. - Miguel ]

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-16-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-16 21:59:19 +01:00
Miguel Ojeda
d7659acca7 rust: add pin-init crate build infrastructure
Add infrastructure for moving the initialization API to its own crate.
Covers all make targets such as `rust-analyzer` and `rustdoc`. The tests
of pin-init are not added to `rusttest`, as they are already tested in
the user-space repository [1].

Link: https://github.com/Rust-for-Linux/pin-init [1]
Co-developed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250308110339.2997091-15-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-16 21:59:19 +01:00
Matthew Maurer
0e446e3145 rust: kbuild: do not export generated KASAN ODR symbols
ASAN generates special synthetic symbols to help check for ODR
violations. These synthetic symbols lack debug information, so
gendwarfksyms emits warnings when processing them. No code should ever
have a dependency on these symbols, so we should not be exporting them,
just like the __cfi symbols.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250122-gendwarfksyms-kasan-rust-v1-1-5ee5658f4fb6@google.com
[ Fixed typo in commit message. Slightly reworded title. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-02-06 19:47:04 +01:00
Justin M. Forbes
a9c621a217 rust: kbuild: add -fzero-init-padding-bits to bindgen_skip_cflags
This seems to break the build when building with gcc15:

    Unable to generate bindings: ClangDiagnostic("error: unknown
    argument: '-fzero-init-padding-bits=all'\n")

Thus skip that flag.

Signed-off-by: Justin M. Forbes <jforbes@fedoraproject.org>
Fixes: dce4aab844 ("kbuild: Use -fzero-init-padding-bits=all")
Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/r/20250129215003.1736127-1-jforbes@fedoraproject.org
[ Slightly reworded commit. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-02-06 17:13:13 +01:00
Tamir Duberstein
b1749432a5 rust: kbuild: use host dylib naming in rusttestlib-kernel
There seems to have been merge skew between commit b2c261fa86 ("rust:
kbuild: expand rusttest target for macros") and commit 0730422bce
("rust: use host dylib naming convention to support macOS") ; the latter
replaced `libmacros.so` with `$(libmacros_name)` and the former added an
instance of `libmacros.so`. The former was not yet applied when the
latter was sent, resulting in a stray `libmacros.so`. Replace the stray
with `$(libmacros_name)` to allow `rusttest` to build on macOS.

Fixes: 0730422bce ("rust: use host dylib naming convention to support macOS")
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Link: https://lore.kernel.org/r/20250201-fix-mac-build-again-v1-1-ca665f5d7de7@gmail.com
[ Slightly reworded title. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-02-06 00:15:27 +01:00
Linus Torvalds
fd8c09ad0d Kbuild updates for v6.14
- Support multiple hook locations for maint scripts of Debian package
 
  - Remove 'cpio' from the build tool requirement
 
  - Introduce gendwarfksyms tool, which computes CRCs for export symbols
    based on the DWARF information
 
  - Support CONFIG_MODVERSIONS for Rust
 
  - Resolve all conflicts in the genksyms parser
 
  - Fix several syntax errors in genksyms
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Merge tag 'kbuild-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Support multiple hook locations for maint scripts of Debian package

 - Remove 'cpio' from the build tool requirement

 - Introduce gendwarfksyms tool, which computes CRCs for export symbols
   based on the DWARF information

 - Support CONFIG_MODVERSIONS for Rust

 - Resolve all conflicts in the genksyms parser

 - Fix several syntax errors in genksyms

* tag 'kbuild-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (64 commits)
  kbuild: fix Clang LTO with CONFIG_OBJTOOL=n
  kbuild: Strip runtime const RELA sections correctly
  kconfig: fix memory leak in sym_warn_unmet_dep()
  kconfig: fix file name in warnings when loading KCONFIG_DEFCONFIG_LIST
  genksyms: fix syntax error for attribute before init-declarator
  genksyms: fix syntax error for builtin (u)int*x*_t types
  genksyms: fix syntax error for attribute after 'union'
  genksyms: fix syntax error for attribute after 'struct'
  genksyms: fix syntax error for attribute after abstact_declarator
  genksyms: fix syntax error for attribute before nested_declarator
  genksyms: fix syntax error for attribute before abstract_declarator
  genksyms: decouple ATTRIBUTE_PHRASE from type-qualifier
  genksyms: record attributes consistently for init-declarator
  genksyms: restrict direct-declarator to take one parameter-type-list
  genksyms: restrict direct-abstract-declarator to take one parameter-type-list
  genksyms: remove Makefile hack
  genksyms: fix last 3 shift/reduce conflicts
  genksyms: fix 6 shift/reduce conflicts and 5 reduce/reduce conflicts
  genksyms: reduce type_qualifier directly to decl_specifier
  genksyms: rename cvar_qualifier to type_qualifier
  ...
2025-01-31 12:07:07 -08:00
Sami Tolvanen
ac61506bf2 rust: Use gendwarfksyms + extended modversions for CONFIG_MODVERSIONS
Previously, two things stopped Rust from using MODVERSIONS:
1. Rust symbols are occasionally too long to be represented in the
   original versions table
2. Rust types cannot be properly hashed by the existing genksyms
   approach because:
	* Looking up type definitions in Rust is more complex than C
	* Type layout is potentially dependent on the compiler in Rust,
	  not just the source type declaration.

CONFIG_EXTENDED_MODVERSIONS addresses the first point, and
CONFIG_GENDWARFKSYMS the second. If Rust wants to use MODVERSIONS, allow
it to do so by selecting both features.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Co-developed-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-01-18 08:51:48 +09:00
HONG Yifan
ceff0757f5 kbuild: rust: add PROCMACROLDFLAGS
These are flags to be passed when linking proc macros for the Rust
toolchain. If unset, it defaults to $(KBUILD_HOSTLDFLAGS).

This is needed because the list of flags to link hostprogs is not
necessarily the same as the list of flags used to link libmacros.so.
When we build proc macros, we need the latter, not the former (e.g. when
using a Rust compiler binary linked to a different C library than host
programs).

To distinguish between the two, introduce this new variable to stand
out from KBUILD_HOSTLDFLAGS used to link other host progs.

Signed-off-by: HONG Yifan <elsk@google.com>
Link: https://lore.kernel.org/r/20241017210430.2401398-2-elsk@google.com
[ v3:

  - `export`ed the variable. Otherwise it would not be visible in
    `rust/Makefile`.

  - Removed "additional" from the documentation and commit message,
    since this actually replaces the other flags, unlike other cases.

  - Added example of use case to documentation and commit message.
    Thanks Alice for the details on what Google needs!

  - Instead of `HOSTLDFLAGS`, used `KBUILD_HOSTLDFLAGS` as the fallback
    to preserve the previous behavior as much as possible, as discussed
    with Alice/Yifan. Thus moved the variable down too (currently we
    do not modify `KBUILD_HOSTLDFLAGS` elsewhere) and avoided
    mentioning `HOSTLDFLAGS` directly in the documentation.

  - Fixed documentation header formatting.

  - Reworded slightly.

         - Miguel ]
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: HONG Yifan <elsk@google.com>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20241112184455.855133-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-01-15 09:53:54 +01:00
Tamir Duberstein
0730422bce rust: use host dylib naming convention to support macOS
Because the `macros` crate exposes procedural macros, it must be
compiled as a dynamic library (so it can be loaded by the compiler at
compile-time).

Before this change the resulting artifact was always named
`libmacros.so`, which works on hosts where this matches the naming
convention for dynamic libraries. However the proper name on macOS would
be `libmacros.dylib`.

This turns out to matter even when the dependency is passed with a path
(`--extern macros=path/to/libmacros.so` rather than `--extern macros`)
because rustc uses the file name to infer the type of the library (see
link). This is because there's no way to specify both the path to and
the type of the external library via CLI flags. The compiler could
speculatively parse the file to determine its type, but it does not do
so today.

This means that libraries that match neither rustc's naming convention
for static libraries nor the platform's naming convention for dynamic
libraries are *rejected*.

The only solution I've found is to follow the host platform's naming
convention. This patch does that by querying the compiler to determine
the appropriate name for the artifact. This allows the kernel to build
with CONFIG_RUST=y on macOS.

Link: https://github.com/rust-lang/rust/blob/d829780/compiler/rustc_metadata/src/locator.rs#L728-L752
Tested-by: Daniel Gomez <da.gomez@samsung.com>
Co-developed-by: Fiona Behrens <me@kloenk.dev>
Signed-off-by: Fiona Behrens <me@kloenk.dev>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20241216-b4-dylib-host-macos-v7-1-cfc507681447@gmail.com
[ Added `MAKEFLAGS=`s to avoid jobserver warnings. Removed space.
  Reworded title. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-01-10 01:01:24 +01:00
Miguel Ojeda
2a87f8b075 rust: kbuild: run Clippy for rusttest code
Running Clippy for `rusttest` code is useful to catch issues there too,
even if the code is not as critical. In the future, this code may also
run in kernelspace and could be copy-pasted. Thus it is useful to keep
it under the same standards. For instance, it will now make us add
`// SAFETY` comments.

It also makes everything more consistent.

Thus clean the few issues spotted by Clippy and start running it.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20241123180639.260191-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-01-10 00:17:25 +01:00
Miguel Ojeda
7a5f93ea58 rust: kbuild: set bindgen's Rust target version
Each `bindgen` release may upgrade the list of Rust targets. For instance,
currently, in their master branch [1], the latest ones are:

    Nightly => {
        vectorcall_abi: #124485,
        ptr_metadata: #81513,
        layout_for_ptr: #69835,
    },
    Stable_1_77(77) => { offset_of: #106655 },
    Stable_1_73(73) => { thiscall_abi: #42202 },
    Stable_1_71(71) => { c_unwind_abi: #106075 },
    Stable_1_68(68) => { abi_efiapi: #105795 },

By default, the highest stable release in their list is used, and users
are expected to set one if they need to support older Rust versions
(e.g. see [2]).

Thus, over time, new Rust features are used by default, and at some
point, it is likely that `bindgen` will emit Rust code that requires a
Rust version higher than our minimum (or perhaps enabling an unstable
feature). Currently, there is no problem because the maximum they have,
as seen above, is Rust 1.77.0, and our current minimum is Rust 1.78.0.

Therefore, set a Rust target explicitly now to prevent going forward in
time too much and thus getting potential build failures at some point.

Since we also support a minimum `bindgen` version, and since `bindgen`
does not support passing unknown Rust target versions, we need to use
the list of our minimum `bindgen` version, rather than the latest. So,
since `bindgen` 0.65.1 had this list [3], we need to use Rust 1.68.0:

    /// Rust stable 1.64
    ///  * `core_ffi_c` ([Tracking issue](https://github.com/rust-lang/rust/issues/94501))
    => Stable_1_64 => 1.64;
    /// Rust stable 1.68
    ///  * `abi_efiapi` calling convention ([Tracking issue](https://github.com/rust-lang/rust/issues/65815))
    => Stable_1_68 => 1.68;
    /// Nightly rust
    ///  * `thiscall` calling convention ([Tracking issue](https://github.com/rust-lang/rust/issues/42202))
    ///  * `vectorcall` calling convention (no tracking issue)
    ///  * `c_unwind` calling convention ([Tracking issue](https://github.com/rust-lang/rust/issues/74990))
    => Nightly => nightly;

    ...

    /// Latest stable release of Rust
    pub const LATEST_STABLE_RUST: RustTarget = RustTarget::Stable_1_68;

Thus add the `--rust-target 1.68` parameter. Add a comment as well
explaining this.

An alternative would be to use the currently running (i.e. actual) `rustc`
and `bindgen` versions to pick a "better" Rust target version. However,
that would introduce more moving parts depending on the user setup and
is also more complex to implement.

Starting with `bindgen` 0.71.0 [4], we will be able to set any future
Rust version instead, i.e. we will be able to set here our minimum
supported Rust version. Christian implemented it [5] after seeing this
patch. Thanks!

Cc: Christian Poveda <git@pvdrz.com>
Cc: Emilio Cobos Álvarez <emilio@crisal.io>
Cc: stable@vger.kernel.org # needed for 6.12.y; unneeded for 6.6.y; do not apply to 6.1.y
Fixes: c844fa64a2 ("rust: start supporting several `bindgen` versions")
Link: 21c60f473f/bindgen/features.rs (L97-L105) [1]
Link: https://github.com/rust-lang/rust-bindgen/issues/2960 [2]
Link: 7d243056d3/bindgen/features.rs (L131-L150) [3]
Link: https://github.com/rust-lang/rust-bindgen/blob/main/CHANGELOG.md#0710-2024-12-06 [4]
Link: https://github.com/rust-lang/rust-bindgen/pull/2993 [5]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20241123180323.255997-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-12-10 01:06:10 +01:00
Linus Torvalds
6a34dfa15d Kbuild updates for v6.13
- Add generic support for built-in boot DTB files
 
  - Enable TAB cycling for dialog buttons in nconfig
 
  - Fix issues in streamline_config.pl
 
  - Refactor Kconfig
 
  - Add support for Clang's AutoFDO (Automatic Feedback-Directed
    Optimization)
 
  - Add support for Clang's Propeller, a profile-guided optimization.
 
  - Change the working directory to the external module directory for M=
    builds
 
  - Support building external modules in a separate output directory
 
  - Enable objtool for *.mod.o and additional kernel objects
 
  - Use lz4 instead of deprecated lz4c
 
  - Work around a performance issue with "git describe"
 
  - Refactor modpost
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Merge tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Add generic support for built-in boot DTB files

 - Enable TAB cycling for dialog buttons in nconfig

 - Fix issues in streamline_config.pl

 - Refactor Kconfig

 - Add support for Clang's AutoFDO (Automatic Feedback-Directed
   Optimization)

 - Add support for Clang's Propeller, a profile-guided optimization.

 - Change the working directory to the external module directory for M=
   builds

 - Support building external modules in a separate output directory

 - Enable objtool for *.mod.o and additional kernel objects

 - Use lz4 instead of deprecated lz4c

 - Work around a performance issue with "git describe"

 - Refactor modpost

* tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (85 commits)
  kbuild: rename .tmp_vmlinux.kallsyms0.syms to .tmp_vmlinux0.syms
  gitignore: Don't ignore 'tags' directory
  kbuild: add dependency from vmlinux to resolve_btfids
  modpost: replace tdb_hash() with hash_str()
  kbuild: deb-pkg: add python3:native to build dependency
  genksyms: reduce indentation in export_symbol()
  modpost: improve error messages in device_id_check()
  modpost: rename alias symbol for MODULE_DEVICE_TABLE()
  modpost: rename variables in handle_moddevtable()
  modpost: move strstarts() to modpost.h
  modpost: convert do_usb_table() to a generic handler
  modpost: convert do_of_table() to a generic handler
  modpost: convert do_pnp_device_entry() to a generic handler
  modpost: convert do_pnp_card_entries() to a generic handler
  modpost: call module_alias_printf() from all do_*_entry() functions
  modpost: pass (struct module *) to do_*_entry() functions
  modpost: remove DEF_FIELD_ADDR_VAR() macro
  modpost: deduplicate MODULE_ALIAS() for all drivers
  modpost: introduce module_alias_printf() helper
  modpost: remove unnecessary check in do_acpi_entry()
  ...
2024-11-30 13:41:50 -08:00
Masahiro Yamada
13b25489b6 kbuild: change working directory to external module directory with M=
Currently, Kbuild always operates in the output directory of the kernel,
even when building external modules. This increases the risk of external
module Makefiles attempting to write to the kernel directory.

This commit switches the working directory to the external module
directory, allowing the removal of the $(KBUILD_EXTMOD)/ prefix from
some build artifacts.

The command for building external modules maintains backward
compatibility, but Makefiles that rely on working in the kernel
directory may break. In such cases, $(objtree) and $(srctree) should
be used to refer to the output and source directories of the kernel.

The appearance of the build log will change as follows:

[Before]

  $ make -C /path/to/my/linux M=/path/to/my/externel/module
  make: Entering directory '/path/to/my/linux'
    CC [M]  /path/to/my/externel/module/helloworld.o
    MODPOST /path/to/my/externel/module/Module.symvers
    CC [M]  /path/to/my/externel/module/helloworld.mod.o
    CC [M]  /path/to/my/externel/module/.module-common.o
    LD [M]  /path/to/my/externel/module/helloworld.ko
  make: Leaving directory '/path/to/my/linux'

[After]

  $ make -C /path/to/my/linux M=/path/to/my/externel/module
  make: Entering directory '/path/to/my/linux'
  make[1]: Entering directory '/path/to/my/externel/module'
    CC [M]  helloworld.o
    MODPOST Module.symvers
    CC [M]  helloworld.mod.o
    CC [M]  .module-common.o
    LD [M]  helloworld.ko
  make[1]: Leaving directory '/path/to/my/externel/module'
  make: Leaving directory '/path/to/my/linux'

Printing "Entering directory" twice is cumbersome. This will be
addressed later.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
2024-11-28 08:10:23 +09:00
Linus Torvalds
798bb342e0 Rust changes for v6.13
Toolchain and infrastructure:
 
  - Enable a series of lints, including safety-related ones, e.g. the
    compiler will now warn about missing safety comments, as well as
    unnecessary ones. How safety documentation is organized is a frequent
    source of review comments, thus having the compiler guide new
    developers on where they are expected (and where not) is very nice.
 
  - Start using '#[expect]': an interesting feature in Rust (stabilized
    in 1.81.0) that makes the compiler warn if an expected warning was
    _not_ emitted. This is useful to avoid forgetting cleaning up locally
    ignored diagnostics ('#[allow]'s).
 
  - Introduce '.clippy.toml' configuration file for Clippy, the Rust
    linter, which will allow us to tweak its behaviour. For instance, our
    first use cases are declaring a disallowed macro and, more
    importantly, enabling the checking of private items.
 
  - Lints-related fixes and cleanups related to the items above.
 
  - Migrate from 'receiver_trait' to 'arbitrary_self_types': to get the
    kernel into stable Rust, one of the major pieces of the puzzle is the
    support to write custom types that can be used as 'self', i.e. as
    receivers, since the kernel needs to write types such as 'Arc' that
    common userspace Rust would not. 'arbitrary_self_types' has been
    accepted to become stable, and this is one of the steps required to
    get there.
 
  - Remove usage of the 'new_uninit' unstable feature.
 
  - Use custom C FFI types. Includes a new 'ffi' crate to contain our
    custom mapping, instead of using the standard library 'core::ffi'
    one. The actual remapping will be introduced in a later cycle.
 
  - Map '__kernel_{size_t,ssize_t,ptrdiff_t}' to 'usize'/'isize' instead
    of 32/64-bit integers.
 
  - Fix 'size_t' in bindgen generated prototypes of C builtins.
 
  - Warn on bindgen < 0.69.5 and libclang >= 19.1 due to a double issue
    in the projects, which we managed to trigger with the upcoming
    tracepoint support. It includes a build test since some distributions
    backported the fix (e.g. Debian -- thanks!). All major distributions
    we list should be now OK except Ubuntu non-LTS.
 
 'macros' crate:
 
  - Adapt the build system to be able run the doctests there too; and
    clean up and enable the corresponding doctests.
 
 'kernel' crate:
 
  - Add 'alloc' module with generic kernel allocator support and remove
    the dependency on the Rust standard library 'alloc' and the extension
    traits we used to provide fallible methods with flags.
 
    Add the 'Allocator' trait and its implementations '{K,V,KV}malloc'.
    Add the 'Box' type (a heap allocation for a single value of type 'T'
    that is also generic over an allocator and considers the kernel's GFP
    flags) and its shorthand aliases '{K,V,KV}Box'. Add 'ArrayLayout'
    type. Add 'Vec' (a contiguous growable array type) and its shorthand
    aliases '{K,V,KV}Vec', including iterator support.
 
    For instance, now we may write code such as:
 
        let mut v = KVec::new();
        v.push(1, GFP_KERNEL)?;
        assert_eq!(&v, &[1]);
 
    Treewide, move as well old users to these new types.
 
  - 'sync' module: add global lock support, including the
    'GlobalLockBackend' trait; the 'Global{Lock,Guard,LockedBy}' types
     and the 'global_lock!' macro. Add the 'Lock::try_lock' method.
 
  - 'error' module: optimize 'Error' type to use 'NonZeroI32' and make
    conversion functions public.
 
  - 'page' module: add 'page_align' function.
 
  - Add 'transmute' module with the existing 'FromBytes' and 'AsBytes'
    traits.
 
  - 'block::mq::request' module: improve rendered documentation.
 
  - 'types' module: extend 'Opaque' type documentation and add simple
    examples for the 'Either' types.
 
 drm/panic:
 
  - Clean up a series of Clippy warnings.
 
 Documentation:
 
  - Add coding guidelines for lints and the '#[expect]' feature.
 
  - Add Ubuntu to the list of distributions in the Quick Start guide.
 
 MAINTAINERS:
  - Add Danilo Krummrich as maintainer of the new 'alloc' module.
 
 And a few other small cleanups and fixes.
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Merge tag 'rust-6.13' of https://github.com/Rust-for-Linux/linux

Pull rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Enable a series of lints, including safety-related ones, e.g. the
     compiler will now warn about missing safety comments, as well as
     unnecessary ones. How safety documentation is organized is a
     frequent source of review comments, thus having the compiler guide
     new developers on where they are expected (and where not) is very
     nice.

   - Start using '#[expect]': an interesting feature in Rust (stabilized
     in 1.81.0) that makes the compiler warn if an expected warning was
     _not_ emitted. This is useful to avoid forgetting cleaning up
     locally ignored diagnostics ('#[allow]'s).

   - Introduce '.clippy.toml' configuration file for Clippy, the Rust
     linter, which will allow us to tweak its behaviour. For instance,
     our first use cases are declaring a disallowed macro and, more
     importantly, enabling the checking of private items.

   - Lints-related fixes and cleanups related to the items above.

   - Migrate from 'receiver_trait' to 'arbitrary_self_types': to get the
     kernel into stable Rust, one of the major pieces of the puzzle is
     the support to write custom types that can be used as 'self', i.e.
     as receivers, since the kernel needs to write types such as 'Arc'
     that common userspace Rust would not. 'arbitrary_self_types' has
     been accepted to become stable, and this is one of the steps
     required to get there.

   - Remove usage of the 'new_uninit' unstable feature.

   - Use custom C FFI types. Includes a new 'ffi' crate to contain our
     custom mapping, instead of using the standard library 'core::ffi'
     one. The actual remapping will be introduced in a later cycle.

   - Map '__kernel_{size_t,ssize_t,ptrdiff_t}' to 'usize'/'isize'
     instead of 32/64-bit integers.

   - Fix 'size_t' in bindgen generated prototypes of C builtins.

   - Warn on bindgen < 0.69.5 and libclang >= 19.1 due to a double issue
     in the projects, which we managed to trigger with the upcoming
     tracepoint support. It includes a build test since some
     distributions backported the fix (e.g. Debian -- thanks!). All
     major distributions we list should be now OK except Ubuntu non-LTS.

  'macros' crate:

   - Adapt the build system to be able run the doctests there too; and
     clean up and enable the corresponding doctests.

  'kernel' crate:

   - Add 'alloc' module with generic kernel allocator support and remove
     the dependency on the Rust standard library 'alloc' and the
     extension traits we used to provide fallible methods with flags.

     Add the 'Allocator' trait and its implementations '{K,V,KV}malloc'.
     Add the 'Box' type (a heap allocation for a single value of type
     'T' that is also generic over an allocator and considers the
     kernel's GFP flags) and its shorthand aliases '{K,V,KV}Box'. Add
     'ArrayLayout' type. Add 'Vec' (a contiguous growable array type)
     and its shorthand aliases '{K,V,KV}Vec', including iterator
     support.

     For instance, now we may write code such as:

         let mut v = KVec::new();
         v.push(1, GFP_KERNEL)?;
         assert_eq!(&v, &[1]);

     Treewide, move as well old users to these new types.

   - 'sync' module: add global lock support, including the
     'GlobalLockBackend' trait; the 'Global{Lock,Guard,LockedBy}' types
     and the 'global_lock!' macro. Add the 'Lock::try_lock' method.

   - 'error' module: optimize 'Error' type to use 'NonZeroI32' and make
     conversion functions public.

   - 'page' module: add 'page_align' function.

   - Add 'transmute' module with the existing 'FromBytes' and 'AsBytes'
     traits.

   - 'block::mq::request' module: improve rendered documentation.

   - 'types' module: extend 'Opaque' type documentation and add simple
     examples for the 'Either' types.

  drm/panic:

   - Clean up a series of Clippy warnings.

  Documentation:

   - Add coding guidelines for lints and the '#[expect]' feature.

   - Add Ubuntu to the list of distributions in the Quick Start guide.

  MAINTAINERS:

   - Add Danilo Krummrich as maintainer of the new 'alloc' module.

  And a few other small cleanups and fixes"

* tag 'rust-6.13' of https://github.com/Rust-for-Linux/linux: (82 commits)
  rust: alloc: Fix `ArrayLayout` allocations
  docs: rust: remove spurious item in `expect` list
  rust: allow `clippy::needless_lifetimes`
  rust: warn on bindgen < 0.69.5 and libclang >= 19.1
  rust: use custom FFI integer types
  rust: map `__kernel_size_t` and friends also to usize/isize
  rust: fix size_t in bindgen prototypes of C builtins
  rust: sync: add global lock support
  rust: macros: enable the rest of the tests
  rust: macros: enable paste! use from macro_rules!
  rust: enable macros::module! tests
  rust: kbuild: expand rusttest target for macros
  rust: types: extend `Opaque` documentation
  rust: block: fix formatting of `kernel::block::mq::request` module
  rust: macros: fix documentation of the paste! macro
  rust: kernel: fix THIS_MODULE header path in ThisModule doc comment
  rust: page: add Rust version of PAGE_ALIGN
  rust: helpers: remove unnecessary header includes
  rust: exports: improve grammar in commentary
  drm/panic: allow verbose version check
  ...
2024-11-26 14:00:26 -08:00
Miguel Ojeda
8af7a50167 rust: jump_label: skip formatting generated file
After a source tree build of the kernel, and having used the `RSCPP`
rule, running `rustfmt` fails with:

    error: macros that expand to items must be delimited with braces or followed by a semicolon
     --> rust/kernel/arch_static_branch_asm.rs:1:27
      |
    1 | ...ls!("1: jmp " ... ".popsection \n\t")
      |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
      |
    help: change the delimiters to curly braces
      |
    1 | ::kernel::concat_literals!{"1: jmp " ... ".popsection \n\t"}
      |                           ~                                ~
    help: add a semicolon
      |
    1 | ::kernel::concat_literals!("1: jmp " ... ".popsection \n\t");
      |                                                             +

This file is not meant to be formatted nor works on its own since it is
meant to be textually included.

Thus skip formatting it by prefixing its name with `generated_`.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Gary Guo <gary@garyguo.net>
Cc: Björn Roy Baron <bjorn3_gh@protonmail.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Trevor Gross <tmgross@umich.edu>
Link: https://lore.kernel.org/20241120175916.58860-1-ojeda@kernel.org
Fixes: 169484ab66 ("rust: add arch_static_branch")
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-20 13:32:42 -05:00
Gary Guo
d072acda48 rust: use custom FFI integer types
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>
2024-11-10 23:58:00 +01:00
Gary Guo
75c1fd41a6 rust: fix size_t in bindgen prototypes of C builtins
Without `-fno-builtin`, for functions like memcpy/memmove (and many
others), bindgen seems to be using the clang-provided prototype. This
prototype is ABI-wise compatible, but the issue is that it does not have
the same information as the source code w.r.t. typedefs.

For example, bindgen generates the following:

    extern "C" {
        pub fn strlen(s: *const core::ffi::c_char) -> core::ffi::c_ulong;
    }

note that the return type is `c_ulong` (i.e. unsigned long), despite the
size_t-is-usize behavior (this is default, and we have not opted out
from it using --no-size_t-is-usize).

Similarly, memchr's size argument should be of type `__kernel_size_t`,
but bindgen generates `c_ulong` directly.

We want to ensure any `size_t` is translated to Rust `usize` so that we
can avoid having them be different type on 32-bit and 64-bit
architectures, and hence would require a lot of excessive type casts
when calling FFI functions.

I found that this bindgen behavior (which probably is caused by
libclang) can be disabled by `-fno-builtin`. Using the flag for compiled
code can result in less optimisation because compiler cannot assume
about their properties anymore, but this should not affect bindgen.

[ Trevor asked: "I wonder how reliable this behavior is. Maybe bindgen
  could do a better job controlling this, is there an open issue?".

  Gary replied: ..."apparently this is indeed the suggested approach in
  https://github.com/rust-lang/rust-bindgen/issues/1770". - Miguel ]

Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240913213041.395655-2-gary@garyguo.net
[ Formatted comment. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-11-10 23:54:43 +01:00
Alice Ryhl
169484ab66 rust: add arch_static_branch
To allow the Rust implementation of static_key_false to use runtime code
patching instead of the generic implementation, pull in the relevant
inline assembly from the jump_label.h header by running the C
preprocessor on a .rs.S file. Build rules are added for .rs.S files.

Since the relevant inline asm has been adjusted to export the inline asm
via the ARCH_STATIC_BRANCH_ASM macro in a consistent way, the Rust side
does not need architecture specific code to pull in the asm.

It is not possible to use the existing C implementation of
arch_static_branch via a Rust helper because it passes the argument
`key` to inline assembly as an 'i' parameter. Any attempt to add a C
helper for this function will fail to compile because the value of `key`
must be known at compile-time.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Cc: Gary Guo <gary@garyguo.net>
Cc: " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " <bjorn3_gh@protonmail.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Anup Patel <apatel@ventanamicro.com>
Cc: Andrew Jones <ajones@ventanamicro.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Conor Dooley <conor.dooley@microchip.com>
Cc: Samuel Holland <samuel.holland@sifive.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Bibo Mao <maobibo@loongson.cn>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tianrui Zhao <zhaotianrui@loongson.cn>
Link: https://lore.kernel.org/20241030-tracepoint-v12-5-eec7f0f8ad22@google.com
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Co-developed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-04 16:21:45 -05:00
Ethan D. Twardy
8d3f50795a rust: enable macros::module! tests
Previously, these tests were ignored due to a missing necessary dependency
on the `kernel` crate. Enable the tests, and update them: for both,
add the parameter to `init()`; for the first one, remove the use of a
kernel parameter mechanism that was never merged.

Signed-off-by: Ethan D. Twardy <ethan.twardy@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://github.com/Rust-for-Linux/linux/issues/1076
Link: https://lore.kernel.org/r/20240704145607.17732-3-ethan.twardy@gmail.com
[ Rebased (moved the `export` to the `rustdoc_test` rule, enable the
  firmware example too). Removed `export` for `RUST_MODFILE`. Removed
  unneeded `rust` language in examples, as well as `#[macro_use]`
  `extern`s. Reworded accordingly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-11-01 22:02:53 +01:00
Ethan D. Twardy
b2c261fa86 rust: kbuild: expand rusttest target for macros
Previously, the rusttest target for the macros crate did not specify
the dependencies necessary to run the rustdoc tests. These tests rely on
the kernel crate, so add the dependencies.

Signed-off-by: Ethan D. Twardy <ethan.twardy@gmail.com>
Link: https://github.com/Rust-for-Linux/linux/issues/1076
Link: https://lore.kernel.org/r/20240704145607.17732-2-ethan.twardy@gmail.com
[ Rebased (`alloc` is gone nowadays, sysroot handling is simpler) and
  simplified (reused `rustdoc_test` rule instead of adding a new one,
  no need for `rustdoc-compiler_builtins`, removed unneeded `macros`
  explicit path). Made `vtable` example fail (avoiding to increase
  the complexity in the `rusttest` target). Removed unstable
  `-Zproc-macro-backtrace` option. Reworded accordingly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-11-01 22:02:03 +01:00
Danilo Krummrich
392e34b6bc kbuild: rust: remove the alloc crate and GlobalAlloc
Now that we have our own `Allocator`, `Box` and `Vec` types we can remove
Rust's `alloc` crate and the `new_uninit` unstable feature.

Also remove `Kmalloc`'s `GlobalAlloc` implementation -- we can't remove
this in a separate patch, since the `alloc` crate requires a
`#[global_allocator]` to set, that implements `GlobalAlloc`.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-29-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-15 23:10:32 +02:00
Miguel Ojeda
bef83245f5 rust: enable rustdoc::unescaped_backticks lint
In Rust 1.71.0, `rustdoc` added the `unescaped_backticks` lint, which
detects what are typically typos in Markdown formatting regarding inline
code [1], e.g. from the Rust standard library:

    /// ... to `deref`/`deref_mut`` must ...

    /// ... use [`from_mut`]`. Specifically, ...

It does not seem to have almost any false positives, from the experience
of enabling it in the Rust standard library [2], which will be checked
starting with Rust 1.82.0. The maintainers also confirmed it is ready
to be used.

Thus enable it.

Link: https://doc.rust-lang.org/rustdoc/lints.html#unescaped_backticks [1]
Link: https://github.com/rust-lang/rust/pull/128307 [2]
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-9-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-07 21:39:05 +02:00
Linus Torvalds
5701725692 Rust changes for v6.12
Toolchain and infrastructure:
 
  - Support 'MITIGATION_{RETHUNK,RETPOLINE,SLS}' (which cleans up objtool
    warnings), teach objtool about 'noreturn' Rust symbols and mimic
    '___ADDRESSABLE()' for 'module_{init,exit}'. With that, we should be
    objtool-warning-free, so enable it to run for all Rust object files.
 
  - KASAN (no 'SW_TAGS'), KCFI and shadow call sanitizer support.
 
  - Support 'RUSTC_VERSION', including re-config and re-build on change.
 
  - Split helpers file into several files in a folder, to avoid conflicts
    in it. Eventually those files will be moved to the right places with
    the new build system. In addition, remove the need to manually export
    the symbols defined there, reusing existing machinery for that.
 
  - Relax restriction on configurations with Rust + GCC plugins to just
    the RANDSTRUCT plugin.
 
 'kernel' crate:
 
  - New 'list' module: doubly-linked linked list for use with reference
    counted values, which is heavily used by the upcoming Rust Binder.
    This includes 'ListArc' (a wrapper around 'Arc' that is guaranteed
    unique for the given ID), 'AtomicTracker' (tracks whether a 'ListArc'
    exists using an atomic), 'ListLinks' (the prev/next pointers for an
    item in a linked list), 'List' (the linked list itself), 'Iter' (an
    iterator over a 'List'), 'Cursor' (a cursor into a 'List' that allows
    to remove elements), 'ListArcField' (a field exclusively owned by a
    'ListArc'), as well as support for heterogeneous lists.
 
  - New 'rbtree' module: red-black tree abstractions used by the upcoming
    Rust Binder. This includes 'RBTree' (the red-black tree itself),
    'RBTreeNode' (a node), 'RBTreeNodeReservation' (a memory reservation
    for a node), 'Iter' and 'IterMut' (immutable and mutable iterators),
    'Cursor' (bidirectional cursor that allows to remove elements), as
    well as an entry API similar to the Rust standard library one.
 
  - 'init' module: add 'write_[pin_]init' methods and the 'InPlaceWrite'
    trait. Add the 'assert_pinned!' macro.
 
  - 'sync' module: implement the 'InPlaceInit' trait for 'Arc' by
    introducing an associated type in the trait.
 
  - 'alloc' module: add 'drop_contents' method to 'BoxExt'.
 
  - 'types' module: implement the 'ForeignOwnable' trait for
    'Pin<Box<T>>' and improve the trait's documentation. In addition,
    add the 'into_raw' method to the 'ARef' type.
 
  - 'error' module: in preparation for the upcoming Rust support for
    32-bit architectures, like arm, locally allow Clippy lint for those.
 
 Documentation:
 
  - https://rust.docs.kernel.org has been announced, so link to it.
 
  - Enable rustdoc's "jump to definition" feature, making its output a
    bit closer to the experience in a cross-referencer.
 
  - Debian Testing now also provides recent Rust releases (outside of
    the freeze period), so add it to the list.
 
 MAINTAINERS:
 
  - Trevor is joining as reviewer of the "RUST" entry.
 
 And a few other small bits.
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Merge tag 'rust-6.12' of https://github.com/Rust-for-Linux/linux

Pull Rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Support 'MITIGATION_{RETHUNK,RETPOLINE,SLS}' (which cleans up
     objtool warnings), teach objtool about 'noreturn' Rust symbols and
     mimic '___ADDRESSABLE()' for 'module_{init,exit}'. With that, we
     should be objtool-warning-free, so enable it to run for all Rust
     object files.

   - KASAN (no 'SW_TAGS'), KCFI and shadow call sanitizer support.

   - Support 'RUSTC_VERSION', including re-config and re-build on
     change.

   - Split helpers file into several files in a folder, to avoid
     conflicts in it. Eventually those files will be moved to the right
     places with the new build system. In addition, remove the need to
     manually export the symbols defined there, reusing existing
     machinery for that.

   - Relax restriction on configurations with Rust + GCC plugins to just
     the RANDSTRUCT plugin.

  'kernel' crate:

   - New 'list' module: doubly-linked linked list for use with reference
     counted values, which is heavily used by the upcoming Rust Binder.

     This includes 'ListArc' (a wrapper around 'Arc' that is guaranteed
     unique for the given ID), 'AtomicTracker' (tracks whether a
     'ListArc' exists using an atomic), 'ListLinks' (the prev/next
     pointers for an item in a linked list), 'List' (the linked list
     itself), 'Iter' (an iterator over a 'List'), 'Cursor' (a cursor
     into a 'List' that allows to remove elements), 'ListArcField' (a
     field exclusively owned by a 'ListArc'), as well as support for
     heterogeneous lists.

   - New 'rbtree' module: red-black tree abstractions used by the
     upcoming Rust Binder.

     This includes 'RBTree' (the red-black tree itself), 'RBTreeNode' (a
     node), 'RBTreeNodeReservation' (a memory reservation for a node),
     'Iter' and 'IterMut' (immutable and mutable iterators), 'Cursor'
     (bidirectional cursor that allows to remove elements), as well as
     an entry API similar to the Rust standard library one.

   - 'init' module: add 'write_[pin_]init' methods and the
     'InPlaceWrite' trait. Add the 'assert_pinned!' macro.

   - 'sync' module: implement the 'InPlaceInit' trait for 'Arc' by
     introducing an associated type in the trait.

   - 'alloc' module: add 'drop_contents' method to 'BoxExt'.

   - 'types' module: implement the 'ForeignOwnable' trait for
     'Pin<Box<T>>' and improve the trait's documentation. In addition,
     add the 'into_raw' method to the 'ARef' type.

   - 'error' module: in preparation for the upcoming Rust support for
     32-bit architectures, like arm, locally allow Clippy lint for
     those.

  Documentation:

   - https://rust.docs.kernel.org has been announced, so link to it.

   - Enable rustdoc's "jump to definition" feature, making its output a
     bit closer to the experience in a cross-referencer.

   - Debian Testing now also provides recent Rust releases (outside of
     the freeze period), so add it to the list.

  MAINTAINERS:

   - Trevor is joining as reviewer of the "RUST" entry.

  And a few other small bits"

* tag 'rust-6.12' of https://github.com/Rust-for-Linux/linux: (54 commits)
  kasan: rust: Add KASAN smoke test via UAF
  kbuild: rust: Enable KASAN support
  rust: kasan: Rust does not support KHWASAN
  kbuild: rust: Define probing macros for rustc
  kasan: simplify and clarify Makefile
  rust: cfi: add support for CFI_CLANG with Rust
  cfi: add CONFIG_CFI_ICALL_NORMALIZE_INTEGERS
  rust: support for shadow call stack sanitizer
  docs: rust: include other expressions in conditional compilation section
  kbuild: rust: replace proc macros dependency on `core.o` with the version text
  kbuild: rust: rebuild if the version text changes
  kbuild: rust: re-run Kconfig if the version text changes
  kbuild: rust: add `CONFIG_RUSTC_VERSION`
  rust: avoid `box_uninit_write` feature
  MAINTAINERS: add Trevor Gross as Rust reviewer
  rust: rbtree: add `RBTree::entry`
  rust: rbtree: add cursor
  rust: rbtree: add mutable iterator
  rust: rbtree: add iterator
  rust: rbtree: add red-black tree implementation backed by the C version
  ...
2024-09-25 10:25:40 -07:00
Matthew Maurer
ca627e6365 rust: cfi: add support for CFI_CLANG with Rust
Make it possible to use the Control Flow Integrity (CFI) sanitizer when
Rust is enabled. Enabling CFI with Rust requires that CFI is configured
to normalize integer types so that all integer types of the same size
and signedness are compatible under CFI.

Rust and C use the same LLVM backend for code generation, so Rust KCFI
is compatible with the KCFI used in the kernel for C. In the case of
FineIBT, CFI also depends on -Zpatchable-function-entry for rewriting
the function prologue, so we set that flag for Rust as well. The flag
for FineIBT requires rustc 1.80.0 or later, so include a Kconfig
requirement for that.

Enabling Rust will select CFI_ICALL_NORMALIZE_INTEGERS because the flag
is required to use Rust with CFI. Using select rather than `depends on`
avoids the case where Rust is not visible in menuconfig due to
CFI_ICALL_NORMALIZE_INTEGERS not being enabled. One disadvantage of
select is that RUST must `depends on` all of the things that
CFI_ICALL_NORMALIZE_INTEGERS depends on to avoid invalid configurations.

Alice has been using KCFI on her phone for several months, so it is
reasonably well tested on arm64.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Gatlin Newhouse <gatlin.newhouse@gmail.com>
Acked-by: Kees Cook <kees@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240801-kcfi-v2-2-c93caed3d121@google.com
[ Replaced `!FINEIBT` requirement with `!CALL_PADDING` to prevent
  a build error on older Rust compilers. Fixed typo. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-09-16 17:29:58 +02:00
Miguel Ojeda
aeb0e24abb kbuild: rust: replace proc macros dependency on core.o with the version text
With the `RUSTC_VERSION_TEXT` rebuild support in place, now proc macros
can depend on that instead of `core.o`.

This means that both the `core` and `macros` crates can be built in
parallel, and that touching `core.o` does not trigger a rebuild of the
proc macros.

This could be accomplished using the same approach as for `core`
(i.e. depending directly on `include/config/RUSTC_VERSION_TEXT`). However,
that is considered an implementation detail [1], and thus it is best
to avoid it. Instead, let fixdep find a string that we explicitly
write down in the source code for this purpose (like it is done for
`include/linux/compiler-version.h`), which we can easily do (unlike for
`core`) since this is our own source code.

Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/rust-for-linux/CAK7LNAQBG0nDupXSgAAk-6nOqeqGVkr3H1RjYaqRJ1OxmLm6xA@mail.gmail.com/ [1]
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20240902165535.1101978-5-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-09-05 22:44:51 +02:00
Miguel Ojeda
ac3e972629 kbuild: rust: rebuild if the version text changes
Now that `RUSTC_VERSION_TEXT` exists, use it to rebuild `core` when the
version text changes (which in turn will trigger a rebuild of all the
kernel Rust code).

This also applies to proc macros (which only work with the `rustc` that
compiled them), via the already existing dependency on `core.o`. That
is cleaned up in the next commit.

However, this does not cover host programs written in Rust, which is
the same case in the C side.

This is accomplished by referencing directly the generated file, instead
of using the `fixdep` header trick, since we cannot change the Rust
standard library sources. This is not too much of a burden, since it
only needs to be done for `core`.

Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20240902165535.1101978-4-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-09-05 22:44:41 +02:00
Miguel Ojeda
6e6efc5fef rust: enable rustdoc's --generate-link-to-definition
In Rust 1.56.0 [1], rustdoc introduced the "jump to definition"
feature [2], i.e. the unstable flag `--generate-link-to-definition`.
It adds links to the source view of the documentation.

For instance, in the source view of `rust/kernel/sync.rs`, for this code:

    impl Default for LockClassKey {
        fn default() -> Self {
            Self::new()
        }
    }

It will add three hyperlinks:

  - `Default` points to the rendered "Trait `core::default::Default`"
    page (not the source view, since it goes to another crate, though
    this may change).

  - `LockClassKey` points to the `pub struct LockClassKey(...);` line
    in the same page, highlighting the line number.

  - `Self::new()` points to the `pub const fn new() -> Self { ... }`
    associated function, highlighting its line numbers (i.e. for the
    full function).

This makes the source view more useful and a bit closer to the experience
in e.g. the Elixir Cross Referencer [3].

I have provisionally enabled it for rust.docs.kernel.org [4] -- one can
take a look at the source view there for an example of how it looks like.

Thus enable it.

Cc: Guillaume Gomez <guillaume1.gomez@gmail.com>
Link: https://github.com/rust-lang/rust/pull/84176 [1]
Link: https://github.com/rust-lang/rust/issues/89095 [2]
Link: https://elixir.bootlin.com [3]
Link: https://rust.docs.kernel.org [4]
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240818141249.387166-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-25 18:37:40 +02:00
Andreas Hindborg
b8673d5693 rust: kbuild: fix export of bss symbols
Symbols in the bss segment are not currently exported. This is a problem
for Rust modules that link against statics, that are resident in the kernel
image. Thus export symbols in the bss segment.

Fixes: 2f7ab1267d ("Kbuild: add Rust support")
Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240815074519.2684107-2-nmi@metaspace.dk
[ Reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-21 01:24:10 +02:00
Miguel Ojeda
76501d19c6 rust: enable bindgen's --enable-function-attribute-detection flag
`bindgen` is able to detect certain function attributes and annotate
functions correspondingly in its output for the Rust side, when the
`--enable-function-attribute-detection` is passed.

In particular, it is currently able to use `__must_check` in C
(`#[must_use]` in Rust), which give us a bunch of annotations that are
nice to have to prevent possible issues in Rust abstractions, e.g.:

     extern "C" {
    +    #[must_use]
         pub fn kobject_add(
             kobj: *mut kobject,
             parent: *mut kobject,
             fmt: *const core::ffi::c_char,
             ...
         ) -> core::ffi::c_int;
     }

Apparently, there are edge cases where this can make generation very slow,
which is why it is behind a flag [1], but it does not seem to affect us
in any major way at the moment.

Thus enable it.

Link: https://github.com/rust-lang/rust-bindgen/issues/1465 [1]
Link: https://lore.kernel.org/rust-for-linux/CANiq72=u5Nrz_NW3U3_VqywJkD8pECA07q2pFDd1wjtXOWdkAQ@mail.gmail.com/
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20240814163722.1550064-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-21 00:37:02 +02:00
Gary Guo
e26fa54604 rust: kbuild: auto generate helper exports
This removes the need to explicitly export all symbols.

Generate helper exports similarly to what's currently done for Rust
crates. These helpers are exclusively called from within Rust code and
therefore can be treated similar as other Rust symbols.

Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20240817165302.3852499-1-gary@garyguo.net
[ Fixed dependency path, reworded slightly, edited comment a bit and
  rebased on top of the changes made when applying Andreas' patch
  (e.g. no `README.md` anymore, so moved the edits).  - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-19 11:09:02 +02:00
Miguel Ojeda
c4d7f546dd objtool/kbuild/rust: enable objtool for Rust
Now that we should be `objtool`-warning free, enable `objtool` for
Rust too.

Before this patch series, we were already getting warnings under e.g. IBT
builds, since those would see Rust code via `vmlinux.o`.

Tested-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240725183325.122827-7-ojeda@kernel.org
[ Solved trivial conflict. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-18 23:34:37 +02:00
Andreas Hindborg
876346536c rust: kbuild: split up helpers.c
This patch splits up the rust helpers C file. When rebasing patch sets on
upstream linux, merge conflicts in helpers.c is common and time consuming
[1]. Thus, split the file so that each kernel component can live in a
separate file.

This patch lists helper files explicitly and thus conflicts in the file
list is still likely. However, they should be more simple to resolve than
the conflicts usually seen in helpers.c.

[ Removed `README.md` and undeleted the original comment since now,
  in v3 of the series, we have a `helpers.c` again; which also allows
  us to keep the "Sorted alphabetically" line and makes the diff easier.

  In addition, updated the Documentation/ mentions of the file, reworded
  title and removed blank lines at the end of `page.c`.  - Miguel ]

Link: https://rust-for-linux.zulipchat.com/#narrow/stream/288089-General/topic/Splitting.20up.20helpers.2Ec/near/426694012 [1]
Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Dirk Behme <dirk.behme@de.bosch.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240815103016.2771842-1-nmi@metaspace.dk
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-18 23:34:26 +02:00
Miguel Ojeda
02dfd63afe rust: add intrinsics to fix -Os builds
Alice reported [1] that an arm64 build failed with:

    ld.lld: error: undefined symbol: __extendsfdf2
    >>> referenced by core.a6f5fc5794e7b7b3-cgu.0
    >>>               rust/core.o:(<f32>::midpoint) in archive vmlinux.a
    >>> referenced by core.a6f5fc5794e7b7b3-cgu.0
    >>>               rust/core.o:(<f32>::midpoint) in archive vmlinux.a

    ld.lld: error: undefined symbol: __truncdfsf2
    >>> referenced by core.a6f5fc5794e7b7b3-cgu.0
    >>>               rust/core.o:(<f32>::midpoint) in archive vmlinux.a

Rust 1.80.0 or later together with `CONFIG_CC_OPTIMIZE_FOR_SIZE=y`
is what triggers it.

In addition, x86_64 builds also fail the same way.

Similarly, compiling with Rust 1.82.0 (currently in nightly) makes
another one appear, possibly due to the LLVM 19 upgrade there:

    ld.lld: error: undefined symbol: __eqdf2
    >>> referenced by core.20495ea57a9f069d-cgu.0
    >>>               rust/core.o:(<f64>::next_up) in archive vmlinux.a
    >>> referenced by core.20495ea57a9f069d-cgu.0
    >>>               rust/core.o:(<f64>::next_down) in archive vmlinux.a

Gary adds [1]:

> Usually the fix on rustc side is to mark those functions as `#[inline]`
>
> All of {midpoint,next_up,next_down} are indeed unstable functions not
> marked as inline...

Fix all those by adding those intrinsics to our usual workaround.

[ Trevor quickly submitted a fix to upstream Rust [2] that has already
  been merged, to be released in Rust 1.82.0 (2024-10-17). - Miguel ]

Cc: Gary Guo <gary@garyguo.net>
Reported-by: Alice Ryhl <aliceryhl@google.com>
Closes: https://rust-for-linux.zulipchat.com/#narrow/stream/x/topic/x/near/455637364 [1]
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://github.com/rust-lang/rust/pull/128749 [2]
Link: https://lore.kernel.org/r/20240806150619.192882-1-ojeda@kernel.org
[ Shortened Zulip link. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-10 00:05:10 +02:00
Zehui Xu
869b5016e9 kbuild: rust: skip -fmin-function-alignment in bindgen flags
GCC 14 recently added -fmin-function-alignment option and the
root Makefile uses it to replace -falign-functions when available.
However, this flag can cause issues when passed to the Rust
Makefile and affect the bindgen process. Bindgen relies on
libclang to parse C code, and currently does not support the
-fmin-function-alignment flag, leading to compilation failures
when GCC 14 is used.

This patch addresses the issue by adding -fmin-function-alignment
to the bindgen_skip_c_flags in rust/Makefile. This prevents the
flag from causing compilation issues.

[ Matthew and Gary confirm function alignment should not change
  the ABI in a way that bindgen would care about, thus we did
  not need the extra logic for bindgen from v2. - Miguel ]

Link: https://lore.kernel.org/linux-kbuild/20240222133500.16991-1-petr.pavlu@suse.com/
Signed-off-by: Zehui Xu <zehuixu@whu.edu.cn>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240731134346.10630-1-zehuixu@whu.edu.cn
[ Reworded title. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-10 00:01:01 +02:00
Sarthak Singh
fe99216357 rust: Support latest version of rust-analyzer
Sets the `sysroot` field in rust-project.json which is now needed in
newer versions of rust-analyzer instead of the `sysroot_src` field.

Till [1] `rust-analyzer` used to guess the `sysroot` based on the
`sysroot_src` at [2]. Now `sysroot` is a required parameter for a
`rust-project.json` file. It is required because `rust-analyzer`
need it to find the proc-macro server [3].

In the current version of `rust-analyzer` the `sysroot_src` is only used
to include the inbuilt library crates (std, core, alloc, etc) [4]. Since
we already specify the core library to be included in the
`rust-project.json` we don't need to define the `sysroot_src`.

Code editors like VS Code try to use the latest version of rust-analyzer
(which is updated every week) instead of the version of rust-analyzer
that comes with the rustup toolchain (which is updated every six weeks
along with the rust version).

Without this change `rust-analyzer` is breaking for anyone using VS Code.
As they are getting the latest version of `rust-analyzer` with the
changes made in [1].

`rust-analyzer` will also start breaking for other developers as they
update their rust version (assuming that also updates the rust-analyzer
version on their system).

This patch should work with every setup as there is no more guess work
being done by `rust-analyzer`.

[ Lukas, who leads the rust-analyzer team, says:

    `sysroot_src` is required now if you want to have the sysroot
    source libraries be loaded. I think we used to infer it as
    `{sysroot}/lib/rustlib/src/rust/library` before when only the
    `sysroot` field was given but that was since changed to make it
    possible in having a sysroot without the standard library sources
    (that is only have the binaries available). So if you want the
    library sources to be loaded by rust-analyzer you will have to set
    that field as well now.

  - Miguel ]

Link: https://github.com/rust-lang/rust-analyzer/pull/17287 [1]
Link: f372a8a117/crates/project-model/src/workspace.rs (L367-L374) [2]
Link: eeb192b79a/crates/project-model/src/sysroot.rs (L180-L192) [3]
Link: https://github.com/search?q=repo%3AVeykril%2Frust-analyzer%20src_root()&type=code [4]
Tested-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Sarthak Singh <sarthak.singh99@gmail.com>
Link: https://rust-for-linux.zulipchat.com/#narrow/stream/291565-Help/topic/How.20to.20rust-analyzer.20correctly.20working
Link: https://lore.kernel.org/r/20240724172713.899399-1-sarthak.singh99@gmail.com
[ Formatted comment, fixed typo and removed spurious empty line. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-07 01:16:52 +02:00
Linus Torvalds
910bfc26d1 Rust changes for v6.11
The highlight is the establishment of a minimum version for the Rust
 toolchain, including 'rustc' (and bundled tools) and 'bindgen'.
 
 The initial minimum will be the pinned version we currently have, i.e.
 we are just widening the allowed versions. That covers 3 stable Rust
 releases: 1.78.0, 1.79.0, 1.80.0 (getting released tomorrow), plus beta,
 plus nightly.
 
 This should already be enough for kernel developers in distributions
 that provide recent Rust compiler versions routinely, such as Arch
 Linux, Debian Unstable (outside the freeze period), Fedora Linux,
 Gentoo Linux (especially the testing channel), Nix (unstable) and
 openSUSE Slowroll and Tumbleweed.
 
 In addition, the kernel is now being built-tested by Rust's pre-merge
 CI. That is, every change that is attempting to land into the Rust
 compiler is tested against the kernel, and it is merged only if it
 passes. Similarly, the bindgen tool has agreed to build the kernel in
 their CI too.
 
 Thus, with the pre-merge CI in place, both projects hope to avoid
 unintentional changes to Rust that break the kernel. This means that,
 in general, apart from intentional changes on their side (that we
 will need to workaround conditionally on our side), the upcoming Rust
 compiler versions should generally work.
 
 In addition, the Rust project has proposed getting the kernel into
 stable Rust (at least solving the main blockers) as one of its three
 flagship goals for 2024H2 [1].
 
 I would like to thank Niko, Sid, Emilio et al. for their help promoting
 the collaboration between Rust and the kernel.
 
 [1] https://rust-lang.github.io/rust-project-goals/2024h2/index.html#flagship-goals
 
 Toolchain and infrastructure:
 
  - Support several Rust toolchain versions.
 
  - Support several bindgen versions.
 
  - Remove 'cargo' requirement and simplify 'rusttest', thanks to 'alloc'
    having been dropped last cycle.
 
  - Provide proper error reporting for the 'rust-analyzer' target.
 
 'kernel' crate:
 
  - Add 'uaccess' module with a safe userspace pointers abstraction.
 
  - Add 'page' module with a 'struct page' abstraction.
 
  - Support more complex generics in workqueue's 'impl_has_work!' macro.
 
 'macros' crate:
 
  - Add 'firmware' field support to the 'module!' macro.
 
  - Improve 'module!' macro documentation.
 
 Documentation:
 
  - Provide instructions on what packages should be installed to build
    the kernel in some popular Linux distributions.
 
  - Introduce the new kernel.org LLVM+Rust toolchains.
 
  - Explain '#[no_std]'.
 
 And a few other small bits.
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Merge tag 'rust-6.11' of https://github.com/Rust-for-Linux/linux

Pull Rust updates from Miguel Ojeda:
 "The highlight is the establishment of a minimum version for the Rust
  toolchain, including 'rustc' (and bundled tools) and 'bindgen'.

  The initial minimum will be the pinned version we currently have, i.e.
  we are just widening the allowed versions. That covers three stable
  Rust releases: 1.78.0, 1.79.0, 1.80.0 (getting released tomorrow),
  plus beta, plus nightly.

  This should already be enough for kernel developers in distributions
  that provide recent Rust compiler versions routinely, such as Arch
  Linux, Debian Unstable (outside the freeze period), Fedora Linux,
  Gentoo Linux (especially the testing channel), Nix (unstable) and
  openSUSE Slowroll and Tumbleweed.

  In addition, the kernel is now being built-tested by Rust's pre-merge
  CI. That is, every change that is attempting to land into the Rust
  compiler is tested against the kernel, and it is merged only if it
  passes. Similarly, the bindgen tool has agreed to build the kernel in
  their CI too.

  Thus, with the pre-merge CI in place, both projects hope to avoid
  unintentional changes to Rust that break the kernel. This means that,
  in general, apart from intentional changes on their side (that we will
  need to workaround conditionally on our side), the upcoming Rust
  compiler versions should generally work.

  In addition, the Rust project has proposed getting the kernel into
  stable Rust (at least solving the main blockers) as one of its three
  flagship goals for 2024H2 [1].

  I would like to thank Niko, Sid, Emilio et al. for their help
  promoting the collaboration between Rust and the kernel.

  Toolchain and infrastructure:

   - Support several Rust toolchain versions.

   - Support several bindgen versions.

   - Remove 'cargo' requirement and simplify 'rusttest', thanks to
     'alloc' having been dropped last cycle.

   - Provide proper error reporting for the 'rust-analyzer' target.

  'kernel' crate:

   - Add 'uaccess' module with a safe userspace pointers abstraction.

   - Add 'page' module with a 'struct page' abstraction.

   - Support more complex generics in workqueue's 'impl_has_work!'
     macro.

  'macros' crate:

   - Add 'firmware' field support to the 'module!' macro.

   - Improve 'module!' macro documentation.

  Documentation:

   - Provide instructions on what packages should be installed to build
     the kernel in some popular Linux distributions.

   - Introduce the new kernel.org LLVM+Rust toolchains.

   - Explain '#[no_std]'.

  And a few other small bits"

Link: https://rust-lang.github.io/rust-project-goals/2024h2/index.html#flagship-goals [1]

* tag 'rust-6.11' of https://github.com/Rust-for-Linux/linux: (26 commits)
  docs: rust: quick-start: add section on Linux distributions
  rust: warn about `bindgen` versions 0.66.0 and 0.66.1
  rust: start supporting several `bindgen` versions
  rust: work around `bindgen` 0.69.0 issue
  rust: avoid assuming a particular `bindgen` build
  rust: start supporting several compiler versions
  rust: simplify Clippy warning flags set
  rust: relax most deny-level lints to warnings
  rust: allow `dead_code` for never constructed bindings
  rust: init: simplify from `map_err` to `inspect_err`
  rust: macros: indent list item in `paste!`'s docs
  rust: add abstraction for `struct page`
  rust: uaccess: add typed accessors for userspace pointers
  uaccess: always export _copy_[from|to]_user with CONFIG_RUST
  rust: uaccess: add userspace pointers
  kbuild: rust-analyzer: improve comment documentation
  kbuild: rust-analyzer: better error handling
  docs: rust: no_std is used
  rust: alloc: add __GFP_HIGHMEM flag
  rust: alloc: fix typo in docs for GFP_NOWAIT
  ...
2024-07-27 13:44:54 -07:00
Miguel Ojeda
f8f88aa25a rust: relax most deny-level lints to warnings
Since we are starting to support several Rust toolchains, lints (including
Clippy ones) now may behave differently and lint groups may include
new lints.

Therefore, to maximize the chances a given version works, relax some
deny-level lints to warnings. It may also make our lives a bit easier
while developing new code or refactoring.

To be clear, the requirements for in-tree code are still the same, since
Rust code still needs to be warning-free (patches should be clean under
`WERROR=y`) and the set of lints is not changed.

`unsafe_op_in_unsafe_fn` is left unmodified, i.e. as an error, since it is
becoming the default in the language (warn-by-default in Rust 2024 [1] and
ideally an error later on) and thus it should also be very well tested. In
addition, it is simple enough that it should not have false positives
(unlike e.g. `rust_2018_idioms`'s `explicit_outlives_requirements`).

`non_ascii_idents` is left unmodified as well, i.e. as an error, since
it is unlikely one gains any productivity during development if it
were a warning (in fact, it may be worse, since it is likely one made
a typo). In addition, it should not have false positives.

Finally, put the two `-D` ones at the top and take the chance to do one
per line.

Link: https://github.com/rust-lang/rust/pull/112038 [1]
Reviewed-by: Finn Behrens <me@kloenk.dev>
Tested-by: Benno Lossin <benno.lossin@proton.me>
Tested-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20240709160615.998336-5-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-10 10:28:51 +02:00
Miguel Ojeda
9ffc80c819 kbuild: rust: remove now-unneeded rusttest custom sysroot handling
Since we dropped our custom `alloc` in commit 9d0441bab7 ("rust: alloc:
remove our fork of the `alloc` crate"), there is no need anymore to keep
the custom sysroot hack.

Thus delete it, which makes the target way simpler and faster too.

This also means we are not using Cargo for anything at the moment,
and that no download is required anymore, so update the main `Makefile`
and the documentation accordingly.

Link: https://lore.kernel.org/r/20240528163502.411600-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-08 22:39:39 +02:00
David Gow
ab0f4cedc3 arch: um: rust: Add i386 support for Rust
At present, Rust in the kernel only supports 64-bit x86, so UML has
followed suit. However, it's significantly easier to support 32-bit i386
on UML than on bare metal, as UML does not use the -mregparm option
(which alters the ABI), which is not yet supported by rustc[1].

Add support for CONFIG_RUST on um/i386, by adding a new target config to
generate_rust_target, and replacing various checks on CONFIG_X86_64 to
also support CONFIG_X86_32.

We still use generate_rust_target, rather than a built-in rustc target,
in order to match x86_64, provide a future place for -mregparm, and more
easily disable floating point instructions.

With these changes, the KUnit tests pass with:
kunit.py run --make_options LLVM=1 --kconfig_add CONFIG_RUST=y
--kconfig_add CONFIG_64BIT=n --kconfig_add CONFIG_FORTIFY_SOURCE=n

An earlier version of these changes was proposed on the Rust-for-Linux
github[2].

[1]: https://github.com/rust-lang/rust/issues/116972
[2]: https://github.com/Rust-for-Linux/linux/pull/966

Signed-off-by: David Gow <davidgow@google.com>
Link: https://patch.msgid.link/20240604224052.3138504-1-davidgow@google.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03 12:22:22 +02:00
Linus Torvalds
4f05e82003 LoongArch changes for v6.10
1, Select some options in Kconfig;
 2, Give a chance to build with !CONFIG_SMP;
 3, Switch to use built-in rustc target;
 4, Add new supported device nodes to dts;
 5, Some bug fixes and other small changes;
 6, Update the default config file.
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Merge tag 'loongarch-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

Pull LoongArch updates from Huacai Chen:

 - Select some options in Kconfig

 - Give a chance to build with !CONFIG_SMP

 - Switch to use built-in rustc target

 - Add new supported device nodes to dts

 - Some bug fixes and other small changes

 - Update the default config file

* tag 'loongarch-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: Update Loongson-3 default config file
  LoongArch: dts: Add new supported device nodes to Loongson-2K2000
  LoongArch: dts: Add new supported device nodes to Loongson-2K0500
  LoongArch: dts: Remove "disabled" state of clock controller node
  LoongArch: rust: Switch to use built-in rustc target
  LoongArch: Fix callchain parse error with kernel tracepoint events again
  LoongArch: Give a chance to build with !CONFIG_SMP
  LoongArch: Select THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE
  LoongArch: Select ARCH_WANT_DEFAULT_BPF_JIT
  LoongArch: Select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
  LoongArch: Select ARCH_HAS_FAST_MULTIPLIER
2024-05-22 09:43:07 -07:00
Linus Torvalds
ff9a79307f Kbuild updates for v6.10
- Avoid 'constexpr', which is a keyword in C23
 
  - Allow 'dtbs_check' and 'dt_compatible_check' run independently of
    'dt_binding_check'
 
  - Fix weak references to avoid GOT entries in position-independent
    code generation
 
  - Convert the last use of 'optional' property in arch/sh/Kconfig
 
  - Remove support for the 'optional' property in Kconfig
 
  - Remove support for Clang's ThinLTO caching, which does not work with
    the .incbin directive
 
  - Change the semantics of $(src) so it always points to the source
    directory, which fixes Makefile inconsistencies between upstream and
    downstream
 
  - Fix 'make tar-pkg' for RISC-V to produce a consistent package
 
  - Provide reasonable default coverage for objtool, sanitizers, and
    profilers
 
  - Remove redundant OBJECT_FILES_NON_STANDARD, KASAN_SANITIZE, etc.
 
  - Remove the last use of tristate choice in drivers/rapidio/Kconfig
 
  - Various cleanups and fixes in Kconfig
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Merge tag 'kbuild-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Avoid 'constexpr', which is a keyword in C23

 - Allow 'dtbs_check' and 'dt_compatible_check' run independently of
   'dt_binding_check'

 - Fix weak references to avoid GOT entries in position-independent code
   generation

 - Convert the last use of 'optional' property in arch/sh/Kconfig

 - Remove support for the 'optional' property in Kconfig

 - Remove support for Clang's ThinLTO caching, which does not work with
   the .incbin directive

 - Change the semantics of $(src) so it always points to the source
   directory, which fixes Makefile inconsistencies between upstream and
   downstream

 - Fix 'make tar-pkg' for RISC-V to produce a consistent package

 - Provide reasonable default coverage for objtool, sanitizers, and
   profilers

 - Remove redundant OBJECT_FILES_NON_STANDARD, KASAN_SANITIZE, etc.

 - Remove the last use of tristate choice in drivers/rapidio/Kconfig

 - Various cleanups and fixes in Kconfig

* tag 'kbuild-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (46 commits)
  kconfig: use sym_get_choice_menu() in sym_check_prop()
  rapidio: remove choice for enumeration
  kconfig: lxdialog: remove initialization with A_NORMAL
  kconfig: m/nconf: merge two item_add_str() calls
  kconfig: m/nconf: remove dead code to display value of bool choice
  kconfig: m/nconf: remove dead code to display children of choice members
  kconfig: gconf: show checkbox for choice correctly
  kbuild: use GCOV_PROFILE and KCSAN_SANITIZE in scripts/Makefile.modfinal
  Makefile: remove redundant tool coverage variables
  kbuild: provide reasonable defaults for tool coverage
  modules: Drop the .export_symbol section from the final modules
  kconfig: use menu_list_for_each_sym() in sym_check_choice_deps()
  kconfig: use sym_get_choice_menu() in conf_write_defconfig()
  kconfig: add sym_get_choice_menu() helper
  kconfig: turn defaults and additional prompt for choice members into error
  kconfig: turn missing prompt for choice members into error
  kconfig: turn conf_choice() into void function
  kconfig: use linked list in sym_set_changed()
  kconfig: gconf: use MENU_CHANGED instead of SYMBOL_CHANGED
  kconfig: gconf: remove debug code
  ...
2024-05-18 12:39:20 -07:00
WANG Rui
8f8d74ee11 LoongArch: rust: Switch to use built-in rustc target
This commit switches to use the LoongArch's built-in rustc target
'loongarch64-unknown-none-softfloat'. The Rust samples have been tested.

Acked-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-05-14 12:24:18 +08:00
Linus Torvalds
8f5b5f7811 Rust changes for v6.10
The most notable change is the drop of the 'alloc' in-tree fork. This
 is nicely reflected in the diffstat as a ~10k lines drop. In turn, this
 makes the version upgrades way simpler and smaller in the future, e.g.
 the latest one in commit 56f64b3706 ("rust: upgrade to Rust 1.78.0").
 
 More importantly, this increases the chances that a newer compiler
 version just works, which in turn means supporting several compiler
 versions is easier now. Thus we will look into finally setting a minimum
 version in the near future.
 
 Toolchain and infrastructure:
 
  - Upgrade to Rust 1.78.0.
 
    This time around, due to how the kernel and Rust schedules have
    aligned, there are two upgrades in fact. These allow us to remove one
    more unstable feature ('offset_of') from the list, among other
    improvements.
 
  - Drop 'alloc' in-tree fork of the standard library crate, which means
    all the unstable features used by 'alloc' (~30 language ones, ~60
    library ones) are not a concern anymore.
 
  - Support DWARFv5 via the '-Zdwarf-version' flag.
 
  - Support zlib and zstd debuginfo compression via the
    '-Zdebuginfo-compression' flag.
 
 'kernel' crate:
 
  - Support allocation flags ('GFP_*'), particularly in 'Box' (via
    'BoxExt'), 'Vec' (via 'VecExt'), 'Arc' and 'UniqueArc', as well as in
    the 'init' module APIs.
 
  - Remove usage of the 'allocator_api' unstable feature.
 
  - Remove 'try_' prefix in allocation APIs' names.
 
  - Add 'VecExt' (an extension trait) to be able to drop the 'alloc'
    fork.
 
  - Add the '{make,to}_{upper,lower}case()' methods to 'CStr'/'CString'.
 
  - Add the 'as_ptr' method to 'ThisModule'.
 
  - Add the 'from_raw' method to 'ArcBorrow'.
 
  - Add the 'into_unique_or_drop' method to 'Arc'.
 
  - Display column number in the 'dbg!' macro output by applying the
    equivalent change done to the standard library one.
 
  - Migrate 'Work' to '#[pin_data]' thanks to the changes in the 'macros'
    crate, which allows to remove an unsafe call in its 'new' associated
    function.
 
  - Prevent namespacing issues when using the '[try_][pin_]init!' macros
    by changing the generated name of guard variables.
 
  - Make the 'get' method in 'Opaque' const.
 
  - Implement the 'Default' trait for 'LockClassKey'.
 
  - Remove unneeded 'kernel::prelude' imports from doctests.
 
  - Remove redundant imports.
 
 'macros' crate:
 
  - Add 'decl_generics' to 'parse_generics()' to support default values,
    and use that to allow them in '#[pin_data]'.
 
 Helpers:
 
  - Trivial English grammar fix.
 
 Documentation:
 
  - Add section on Rust Kselftests to the "Testing" document.
 
  - Expand the "Abstractions vs. bindings" section of the "General
    Information" document.
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Merge tag 'rust-6.10' of https://github.com/Rust-for-Linux/linux

Pull Rust updates from Miguel Ojeda:
 "The most notable change is the drop of the 'alloc' in-tree fork. This
  is nicely reflected in the diffstat as a ~10k lines drop. In turn,
  this makes the version upgrades way simpler and smaller in the future,
  e.g. the latest one in commit 56f64b3706 ("rust: upgrade to Rust
  1.78.0").

  More importantly, this increases the chances that a newer compiler
  version just works, which in turn means supporting several compiler
  versions is easier now. Thus we will look into finally setting a
  minimum version in the near future.

  Toolchain and infrastructure:

   - Upgrade to Rust 1.78.0

     This time around, due to how the kernel and Rust schedules have
     aligned, there are two upgrades in fact. These allow us to remove
     one more unstable feature ('offset_of') from the list, among other
     improvements

   - Drop 'alloc' in-tree fork of the standard library crate, which
     means all the unstable features used by 'alloc' (~30 language ones,
     ~60 library ones) are not a concern anymore

   - Support DWARFv5 via the '-Zdwarf-version' flag

   - Support zlib and zstd debuginfo compression via the
     '-Zdebuginfo-compression' flag

  'kernel' crate:

   - Support allocation flags ('GFP_*'), particularly in 'Box' (via
     'BoxExt'), 'Vec' (via 'VecExt'), 'Arc' and 'UniqueArc', as well as
     in the 'init' module APIs

   - Remove usage of the 'allocator_api' unstable feature

   - Remove 'try_' prefix in allocation APIs' names

   - Add 'VecExt' (an extension trait) to be able to drop the 'alloc'
     fork

   - Add the '{make,to}_{upper,lower}case()' methods to 'CStr'/'CString'

   - Add the 'as_ptr' method to 'ThisModule'

   - Add the 'from_raw' method to 'ArcBorrow'

   - Add the 'into_unique_or_drop' method to 'Arc'

   - Display column number in the 'dbg!' macro output by applying the
     equivalent change done to the standard library one

   - Migrate 'Work' to '#[pin_data]' thanks to the changes in the
     'macros' crate, which allows to remove an unsafe call in its 'new'
     associated function

   - Prevent namespacing issues when using the '[try_][pin_]init!'
     macros by changing the generated name of guard variables

   - Make the 'get' method in 'Opaque' const

   - Implement the 'Default' trait for 'LockClassKey'

   - Remove unneeded 'kernel::prelude' imports from doctests

   - Remove redundant imports

  'macros' crate:

   - Add 'decl_generics' to 'parse_generics()' to support default
     values, and use that to allow them in '#[pin_data]'

  Helpers:

   - Trivial English grammar fix

  Documentation:

   - Add section on Rust Kselftests to the 'Testing' document

   - Expand the 'Abstractions vs. bindings' section of the 'General
     Information' document"

* tag 'rust-6.10' of https://github.com/Rust-for-Linux/linux: (31 commits)
  rust: alloc: fix dangling pointer in VecExt<T>::reserve()
  rust: upgrade to Rust 1.78.0
  rust: kernel: remove redundant imports
  rust: sync: implement `Default` for `LockClassKey`
  docs: rust: extend abstraction and binding documentation
  docs: rust: Add instructions for the Rust kselftest
  rust: remove unneeded `kernel::prelude` imports from doctests
  rust: update `dbg!()` to format column number
  rust: helpers: Fix grammar in comment
  rust: init: change the generated name of guard variables
  rust: sync: add `Arc::into_unique_or_drop`
  rust: sync: add `ArcBorrow::from_raw`
  rust: types: Make Opaque::get const
  rust: kernel: remove usage of `allocator_api` unstable feature
  rust: init: update `init` module to take allocation flags
  rust: sync: update `Arc` and `UniqueArc` to take allocation flags
  rust: alloc: update `VecExt` to take allocation flags
  rust: alloc: introduce the `BoxExt` trait
  rust: alloc: introduce allocation flags
  rust: alloc: remove our fork of the `alloc` crate
  ...
2024-05-13 15:13:54 -07:00
Masahiro Yamada
b1992c3772 kbuild: use $(src) instead of $(srctree)/$(src) for source directory
Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention without any functional
difference. In fact, $(obj) and $(src) are exactly the same, as defined
in scripts/Makefile.build:

    src := $(obj)

When the kernel is built in a separate output directory, $(src) does
not accurately reflect the source directory location. While Kbuild
resolves this discrepancy by specifying VPATH=$(srctree) to search for
source files, it does not cover all cases. For example, when adding a
header search path for local headers, -I$(srctree)/$(src) is typically
passed to the compiler.

This introduces inconsistency between upstream and downstream Makefiles
because $(src) is used instead of $(srctree)/$(src) for the latter.

To address this inconsistency, this commit changes the semantics of
$(src) so that it always points to the directory in the source tree.

Going forward, the variables used in Makefiles will have the following
meanings:

  $(obj)     - directory in the object tree
  $(src)     - directory in the source tree  (changed by this commit)
  $(objtree) - the top of the kernel object tree
  $(srctree) - the top of the kernel source tree

Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced
with $(src).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-05-10 04:34:52 +09:00
Miguel Ojeda
50cfe93b01 kbuild: rust: remove unneeded @rustc_cfg to avoid ICE
When KUnit tests are enabled, under very big kernel configurations
(e.g. `allyesconfig`), we can trigger a `rustdoc` ICE [1]:

      RUSTDOC TK rust/kernel/lib.rs
    error: the compiler unexpectedly panicked. this is a bug.

The reason is that this build step has a duplicated `@rustc_cfg` argument,
which contains the kernel configuration, and thus a lot of arguments. The
factor 2 happens to be enough to reach the ICE.

Thus remove the unneeded `@rustc_cfg`. By doing so, we clean up the
command and workaround the ICE.

The ICE has been fixed in the upcoming Rust 1.79 [2].

Cc: stable@vger.kernel.org
Fixes: a66d733da8 ("rust: support running Rust documentation tests as KUnit ones")
Link: https://github.com/rust-lang/rust/issues/122722 [1]
Link: https://github.com/rust-lang/rust/pull/122840 [2]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240422091215.526688-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-04-23 00:38:55 +02:00
Wedson Almeida Filho
11795ae4cc kbuild: use the upstream alloc crate
Switch away from our fork of the `alloc` crate. We remove it altogether
in the next commit.

Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20240328013603.206764-4-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-04-16 22:03:14 +02:00
Linus Torvalds
1d35aae78f Kbuild updates for v6.9
- Generate a list of built DTB files (arch/*/boot/dts/dtbs-list)
 
  - Use more threads when building Debian packages in parallel
 
  - Fix warnings shown during the RPM kernel package uninstallation
 
  - Change OBJECT_FILES_NON_STANDARD_*.o etc. to take a relative path to
    Makefile
 
  - Support GCC's -fmin-function-alignment flag
 
  - Fix a null pointer dereference bug in modpost
 
  - Add the DTB support to the RPM package
 
  - Various fixes and cleanups in Kconfig
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Merge tag 'kbuild-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Generate a list of built DTB files (arch/*/boot/dts/dtbs-list)

 - Use more threads when building Debian packages in parallel

 - Fix warnings shown during the RPM kernel package uninstallation

 - Change OBJECT_FILES_NON_STANDARD_*.o etc. to take a relative path to
   Makefile

 - Support GCC's -fmin-function-alignment flag

 - Fix a null pointer dereference bug in modpost

 - Add the DTB support to the RPM package

 - Various fixes and cleanups in Kconfig

* tag 'kbuild-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (67 commits)
  kconfig: tests: test dependency after shuffling choices
  kconfig: tests: add a test for randconfig with dependent choices
  kconfig: tests: support KCONFIG_SEED for the randconfig runner
  kbuild: rpm-pkg: add dtb files in kernel rpm
  kconfig: remove unneeded menu_is_visible() call in conf_write_defconfig()
  kconfig: check prompt for choice while parsing
  kconfig: lxdialog: remove unused dialog colors
  kconfig: lxdialog: fix button color for blackbg theme
  modpost: fix null pointer dereference
  kbuild: remove GCC's default -Wpacked-bitfield-compat flag
  kbuild: unexport abs_srctree and abs_objtree
  kbuild: Move -Wenum-{compare-conditional,enum-conversion} into W=1
  kconfig: remove named choice support
  kconfig: use linked list in get_symbol_str() to iterate over menus
  kconfig: link menus to a symbol
  kbuild: fix inconsistent indentation in top Makefile
  kbuild: Use -fmin-function-alignment when available
  alpha: merge two entries for CONFIG_ALPHA_GAMMA
  alpha: merge two entries for CONFIG_ALPHA_EV4
  kbuild: change DTC_FLAGS_<basetarget>.o to take the path relative to $(obj)
  ...
2024-03-21 14:41:00 -07:00
Linus Torvalds
6d75c6f40a arm64 updates for 6.9:
* Reorganise the arm64 kernel VA space and add support for LPA2 (at
   stage 1, KVM stage 2 was merged earlier) - 52-bit VA/PA address range
   with 4KB and 16KB pages
 
 * Enable Rust on arm64
 
 * Support for the 2023 dpISA extensions (data processing ISA), host only
 
 * arm64 perf updates:
 
   - StarFive's StarLink (integrates one or more CPU cores with a shared
     L3 memory system) PMU support
 
   - Enable HiSilicon Erratum 162700402 quirk for HIP09
 
   - Several updates for the HiSilicon PCIe PMU driver
 
   - Arm CoreSight PMU support
 
   - Convert all drivers under drivers/perf/ to use .remove_new()
 
 * Miscellaneous:
 
   - Don't enable workarounds for "rare" errata by default
 
   - Clean up the DAIF flags handling for EL0 returns (in preparation for
     NMI support)
 
   - Kselftest update for ptrace()
 
   - Update some of the sysreg field definitions
 
   - Slight improvement in the code generation for inline asm I/O
     accessors to permit offset addressing
 
   - kretprobes: acquire regs via a BRK exception (previously done via a
     trampoline handler)
 
   - SVE/SME cleanups, comment updates
 
   - Allow CALL_OPS+CC_OPTIMIZE_FOR_SIZE with clang (previously disabled
     due to gcc silently ignoring -falign-functions=N)
 -----BEGIN PGP SIGNATURE-----
 
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:
 "The major features are support for LPA2 (52-bit VA/PA with 4K and 16K
  pages), the dpISA extension and Rust enabled on arm64. The changes are
  mostly contained within the usual arch/arm64/, drivers/perf, the arm64
  Documentation and kselftests. The exception is the Rust support which
  touches some generic build files.

  Summary:

   - Reorganise the arm64 kernel VA space and add support for LPA2 (at
     stage 1, KVM stage 2 was merged earlier) - 52-bit VA/PA address
     range with 4KB and 16KB pages

   - Enable Rust on arm64

   - Support for the 2023 dpISA extensions (data processing ISA), host
     only

   - arm64 perf updates:

      - StarFive's StarLink (integrates one or more CPU cores with a
        shared L3 memory system) PMU support

      - Enable HiSilicon Erratum 162700402 quirk for HIP09

      - Several updates for the HiSilicon PCIe PMU driver

      - Arm CoreSight PMU support

      - Convert all drivers under drivers/perf/ to use .remove_new()

   - Miscellaneous:

      - Don't enable workarounds for "rare" errata by default

      - Clean up the DAIF flags handling for EL0 returns (in preparation
        for NMI support)

      - Kselftest update for ptrace()

      - Update some of the sysreg field definitions

      - Slight improvement in the code generation for inline asm I/O
        accessors to permit offset addressing

      - kretprobes: acquire regs via a BRK exception (previously done
        via a trampoline handler)

      - SVE/SME cleanups, comment updates

      - Allow CALL_OPS+CC_OPTIMIZE_FOR_SIZE with clang (previously
        disabled due to gcc silently ignoring -falign-functions=N)"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (134 commits)
  Revert "mm: add arch hook to validate mmap() prot flags"
  Revert "arm64: mm: add support for WXN memory translation attribute"
  Revert "ARM64: Dynamically allocate cpumasks and increase supported CPUs to 512"
  ARM64: Dynamically allocate cpumasks and increase supported CPUs to 512
  kselftest/arm64: Add 2023 DPISA hwcap test coverage
  kselftest/arm64: Add basic FPMR test
  kselftest/arm64: Handle FPMR context in generic signal frame parser
  arm64/hwcap: Define hwcaps for 2023 DPISA features
  arm64/ptrace: Expose FPMR via ptrace
  arm64/signal: Add FPMR signal handling
  arm64/fpsimd: Support FEAT_FPMR
  arm64/fpsimd: Enable host kernel access to FPMR
  arm64/cpufeature: Hook new identification registers up to cpufeature
  docs: perf: Fix build warning of hisi-pcie-pmu.rst
  perf: starfive: Only allow COMPILE_TEST for 64-bit architectures
  MAINTAINERS: Add entry for StarFive StarLink PMU
  docs: perf: Add description for StarFive's StarLink PMU
  dt-bindings: perf: starfive: Add JH8100 StarLink PMU
  perf: starfive: Add StarLink PMU support
  docs: perf: Update usage for target filter of hisi-pcie-pmu
  ...
2024-03-14 15:35:42 -07:00
Masahiro Yamada
e2bad142bb kbuild: unexport abs_srctree and abs_objtree
Commit 25b146c5b8 ("kbuild: allow Kbuild to start from any directory")
exported abs_srctree and abs_objtree to avoid recomputation after the
sub-make. However, this approach turned out to be fragile.

Commit 5fa94ceb79 ("kbuild: set correct abs_srctree and abs_objtree
for package builds") moved them above "ifneq ($(sub_make_done),1)",
eliminating the need for exporting them.

These are only needed in the top Makefile. If an absolute path is
required in sub-directories, you can use $(abspath ) or $(realpath )
as needed.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-03-10 17:27:17 +09:00
Miguel Ojeda
ecab4115c4 kbuild: mark rustc (and others) invocations as recursive
`rustc` (like Cargo) may take advantage of the jobserver at any time
(e.g. for backend parallelism, or eventually frontend too). In the kernel,
we call `rustc` with `-Ccodegen-units=1` (and `-Zthreads` is 1 so far),
so we do not expect parallelism. However, in the upcoming Rust 1.76.0, a
warning is emitted by `rustc` [1] when it cannot connect to the jobserver
it was passed (in many cases, but not all: compiling and `--print sysroot`
do, but `--version` does not). And given GNU Make always passes
the jobserver in the environment variable (even when a line is deemed
non-recursive), `rustc` will end up complaining about it (in particular
in Make 4.3 where there is only the simple pipe jobserver style).

One solution is to remove the jobserver from `MAKEFLAGS`. However, we
can mark the lines with calls to `rustc` (and Cargo) as recursive, which
looks simpler. This is being documented as a recommendation in `rustc`
[2] and allows us to be ready for the time we may use parallelism inside
`rustc` (potentially now, if a user passes `-Zthreads`). Thus do so.

Similarly, do the same for `rustdoc` and `cargo` calls.

Finally, there is one case that the solution does not cover, which is the
`$(shell ...)` call we have. Thus, for that one, set an empty `MAKEFLAGS`
environment variable.

Link: https://github.com/rust-lang/rust/issues/120515 [1]
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://github.com/rust-lang/rust/pull/121564 [2]
Link: https://lore.kernel.org/r/20240217002638.57373-1-ojeda@kernel.org
[ Reworded to add link to PR documenting the recommendation. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-29 22:16:38 +01:00
Jamie Cunliffe
724a75ac95 arm64: rust: Enable Rust support for AArch64
This commit provides the build flags for Rust for AArch64. The core Rust
support already in the kernel does the rest. This enables the PAC ret
and BTI options in the Rust build flags to match the options that are
used when building C.

The Rust samples have been tested with this commit.

Signed-off-by: Jamie Cunliffe <Jamie.Cunliffe@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Tested-by: Dirk Behme <dirk.behme@de.bosch.com>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Fabien Parent <fabien.parent@linaro.org>
Link: https://lore.kernel.org/r/20231020155056.3495121-3-Jamie.Cunliffe@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-02-09 16:12:36 +00:00
Jamie Cunliffe
f82811e22b rust: Refactor the build target to allow the use of builtin targets
Eventually we want all architectures to be using the target as defined
by rustc. However currently some architectures can't do that and are
using the target.json specification. This puts in place the foundation
to allow the use of the builtin target definition or a target.json
specification.

Signed-off-by: Jamie Cunliffe <Jamie.Cunliffe@arm.com>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20231020155056.3495121-2-Jamie.Cunliffe@arm.com
[catalin.marinas@arm.com: squashed loongarch ifneq fix from WANG Rui]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-02-09 16:11:07 +00:00
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 <gary@garyguo.net>
Reported-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Closes: https://lore.kernel.org/r/20231026.204058.2167744626131849993.fujita.tomonori@gmail.com [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 <yakoyoku@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20231215235428.243211-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-12-21 20:54:17 +01:00
Matthew Maurer
71479eee9d rust: Suppress searching builtin sysroot
By default, if Rust is passed `--target=foo` rather than a target.json
file, it will infer a default sysroot if that component is installed. As
the proposed aarch64 support [1] uses `aarch64-unknown-none` rather than a
target.json file, this is needed [2] to prevent rustc from being confused
between the custom kernel sysroot and the pre-installed one.

[ Miguel: Applied Boqun's extra case (for `rusttest`) and reworded to add
  links to the arm64 patch series discussion. In addition, fixed the
  `rustdoc` target too (which requires a conditional since `cmd_rustdoc`
  is also used for host crates like `macros`). ]

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/rust-for-linux/20231020155056.3495121-1-Jamie.Cunliffe@arm.com/ [1]
Link: https://lore.kernel.org/rust-for-linux/CAGSQo01pOixiPXkW867h4vPUaAjtKtHGKhkV-rpifJvKxAf4Ww@mail.gmail.com/ [2]
Link: https://lore.kernel.org/r/20231031201752.1189213-1-mmaurer@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-12-14 20:14:01 +01:00
Gary Guo
743766565d rust: bindings: rename const binding using sed
Currently, for `const`s that bindgen doesn't recognise, we define a
helper constant with

    const <TYPE> BINDINGS_<NAME> = <NAME>;

in `bindings_helper.h` and then we put

    pub const <NAME>: <TYPE> = BINDINGS_<NAME>;

in `bindings/lib.rs`. This is fine since we currently only have 3
constants that are defined this way, but is going to be more annoying
when more constants are added since every new constant needs to be
defined in two places.

This patch changes the way we define constant helpers to

    const <TYPE> RUST_CONST_HELPER_<NAME> = <NAME>;

and then use `sed` to postprocess Rust code generated by bindgen to
remove the distinct prefix, so users of the `bindings` crate can refer
to the name directly.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20231104145700.2495176-1-gary@garyguo.net
[ Reworded for typos. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-12-14 20:14:01 +01:00
Linus Torvalds
5c5e048b24 Kbuild updates for v6.7
- Implement the binary search in modpost for faster symbol lookup
 
  - Respect HOSTCC when linking host programs written in Rust
 
  - Change the binrpm-pkg target to generate kernel-devel RPM package
 
  - Fix endianness issues for tee and ishtp MODULE_DEVICE_TABLE
 
  - Unify vdso_install rules
 
  - Remove unused __memexit* annotations
 
  - Eliminate stale whitelisting for __devinit/__devexit from modpost
 
  - Enable dummy-tools to handle the -fpatchable-function-entry flag
 
  - Add 'userldlibs' syntax
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Merge tag 'kbuild-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Implement the binary search in modpost for faster symbol lookup

 - Respect HOSTCC when linking host programs written in Rust

 - Change the binrpm-pkg target to generate kernel-devel RPM package

 - Fix endianness issues for tee and ishtp MODULE_DEVICE_TABLE

 - Unify vdso_install rules

 - Remove unused __memexit* annotations

 - Eliminate stale whitelisting for __devinit/__devexit from modpost

 - Enable dummy-tools to handle the -fpatchable-function-entry flag

 - Add 'userldlibs' syntax

* tag 'kbuild-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits)
  kbuild: support 'userldlibs' syntax
  kbuild: dummy-tools: pretend we understand -fpatchable-function-entry
  kbuild: Correct missing architecture-specific hyphens
  modpost: squash ALL_{INIT,EXIT}_TEXT_SECTIONS to ALL_TEXT_SECTIONS
  modpost: merge sectioncheck table entries regarding init/exit sections
  modpost: use ALL_INIT_SECTIONS for the section check from DATA_SECTIONS
  modpost: disallow the combination of EXPORT_SYMBOL and __meminit*
  modpost: remove EXIT_SECTIONS macro
  modpost: remove MEM_INIT_SECTIONS macro
  modpost: remove more symbol patterns from the section check whitelist
  modpost: disallow *driver to reference .meminit* sections
  linux/init: remove __memexit* annotations
  modpost: remove ALL_EXIT_DATA_SECTIONS macro
  kbuild: simplify cmd_ld_multi_m
  kbuild: avoid too many execution of scripts/pahole-flags.sh
  kbuild: remove ARCH_POSTLINK from module builds
  kbuild: unify no-compiler-targets and no-sync-config-targets
  kbuild: unify vdso_install rules
  docs: kbuild: add INSTALL_DTBS_PATH
  UML: remove unused cmd_vdso_install
  ...
2023-11-04 08:07:19 -10:00
Linus Torvalds
455cdcb45f Rust changes for v6.7
A small one compared to the previous one in terms of features. In terms
 of lines, as usual, the 'alloc' version upgrade accounts for most of them.
 
 Toolchain and infrastructure:
 
  - Upgrade to Rust 1.73.0.
 
    This time around, due to how the kernel and Rust schedules have
    aligned, there are two upgrades in fact. They contain the fixes for
    a few issues we reported to the Rust project.
 
    In addition, a few cleanups indicated by the upgraded compiler
    or possible thanks to it. For instance, the compiler now detects
    redundant explicit links.
 
  - A couple changes to the Rust 'Makefile' so that it can be used with
    toybox tools, allowing Rust to be used in the Android kernel build.
 
 x86:
 
  - Enable IBT if enabled in C.
 
 Documentation:
 
  - Add "The Rust experiment" section to the Rust index page.
 
 MAINTAINERS
 
  - Add Maintainer Entry Profile field ('P:').
 
  - Update our 'W:' field to point to the webpage we have been building
    this year.
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Merge tag 'rust-6.7' of https://github.com/Rust-for-Linux/linux

Pull rust updates from Miguel Ojeda:
 "A small one compared to the previous one in terms of features. In
  terms of lines, as usual, the 'alloc' version upgrade accounts for
  most of them.

  Toolchain and infrastructure:

   - Upgrade to Rust 1.73.0

     This time around, due to how the kernel and Rust schedules have
     aligned, there are two upgrades in fact. They contain the fixes for
     a few issues we reported to the Rust project.

     In addition, a few cleanups indicated by the upgraded compiler or
     possible thanks to it. For instance, the compiler now detects
     redundant explicit links.

   - A couple changes to the Rust 'Makefile' so that it can be used with
     toybox tools, allowing Rust to be used in the Android kernel build.

  x86:

   - Enable IBT if enabled in C

  Documentation:

   - Add "The Rust experiment" section to the Rust index page

  MAINTAINERS:

   - Add Maintainer Entry Profile field ('P:').

   - Update our 'W:' field to point to the webpage we have been building
     this year"

* tag 'rust-6.7' of https://github.com/Rust-for-Linux/linux:
  docs: rust: add "The Rust experiment" section
  x86: Enable IBT in Rust if enabled in C
  rust: Use grep -Ev rather than relying on GNU grep
  rust: Use awk instead of recent xargs
  rust: upgrade to Rust 1.73.0
  rust: print: use explicit link in documentation
  rust: task: remove redundant explicit link
  rust: kernel: remove `#[allow(clippy::new_ret_no_self)]`
  MAINTAINERS: add Maintainer Entry Profile field for Rust
  MAINTAINERS: update Rust webpage
  rust: upgrade to Rust 1.72.1
  rust: arc: add explicit `drop()` around `Box::from_raw()`
2023-10-30 20:30:49 -10:00
Miguel Ojeda
cfd96726e6 rust: docs: fix logo replacement
The static files placement by `rustdoc` changed in Rust 1.67.0 [1],
but the custom code we have to replace the logo in the generated
HTML files did not get updated.

Thus update it to have the Linux logo again in the output.

Hopefully `rustdoc` will eventually support a custom logo from
a local file [2], so that we do not need to maintain this hack
on our side.

Link: https://github.com/rust-lang/rust/pull/101702 [1]
Link: https://github.com/rust-lang/rfcs/pull/3226 [2]
Fixes: 3ed03f4da0 ("rust: upgrade to Rust 1.68.2")
Cc: stable@vger.kernel.org
Tested-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20231018155527.1015059-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-10-19 16:40:00 +02:00
Matthew Maurer
a7135d1075 rust: Use grep -Ev rather than relying on GNU grep
While GNU grep supports '\|' when in basic regular expression mode, not
all grep implementations do (notably toybox grep, used to build the
Android kernel, does not). Switching to grep -Ev enables extended
regular expressions which includes support for the '|' operator.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20230928201421.2296518-1-mmaurer@google.com
[ Reworded for typo. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-10-15 21:56:26 +02:00
Matthew Maurer
45f97e6385 rust: Use awk instead of recent xargs
`awk` is already required by the kernel build, and the `xargs` feature
used in current Rust detection is not present in all `xargs` (notably,
toybox based xargs, used in the Android kernel build).

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Link: https://lore.kernel.org/r/20230928205045.2375899-1-mmaurer@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-10-15 21:48:24 +02:00
Matthew Maurer
80bac83a73 rust: Respect HOSTCC when linking for host
Currently, rustc defaults to invoking `cc`, even if `HOSTCC` is defined,
resulting in build failures in hermetic environments where `cc` does not
exist. This includes both hostprogs and proc-macros.

Since we are setting the linker to `HOSTCC`, we set the linker flavor to
`gcc` explicitly. The linker-flavor selects both which linker to search
for if the linker is unset, and which kind of linker flags to pass.
Without this flag, `rustc` would attempt to determine which flags to
pass based on the name of the binary passed as `HOSTCC`. `gcc` is the
name of the linker-flavor used by `rustc` for all C compilers, including
both `gcc` and `clang`.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-10-14 18:26:28 +09:00
Andrea Righi
344b6c0a75 rust: fix bindgen build error with fstrict-flex-arrays
Commit df8fc4e934 ("kbuild: Enable -fstrict-flex-arrays=3") enabled
'-fstrict-flex-arrays=3' globally, but bindgen does not recognized this
compiler option, triggering the following build error:

 error: unknown argument: '-fstrict-flex-arrays=3', err: true

[ Miguel: Commit df8fc4e934 ("kbuild: Enable -fstrict-flex-arrays=3")
  did it so only conditionally (i.e. only if the C compiler supports
  it). This explains what Andrea was seeing: he was  compiling with a
  modern enough GCC, which enables the option, but with an old enough
  Clang. Andrea confirmed this was the case: he was using Clang 14 with
  GCC 13; and that Clang 15 worked for him.

  While it is possible to construct code (see mailing list for an
  example I came up with) where this could break, it is fairly
  contrived, and anyway GCC-built kernels with Rust enabled should
  only be used for experimentation until we get support for
  `rustc_codegen_gcc` and/or GCC Rust. So let's add this for the
  time being in case it helps somebody. ]

Add '-fstrict-flex-arrays' to the list of cflags that should be ignored
by bindgen.

Fixes: df8fc4e934 ("kbuild: Enable -fstrict-flex-arrays=3")
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Tested-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20230815065346.131387-1-andrea.righi@canonical.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-10-12 22:58:52 +02:00
Linus Torvalds
cd99b9eb4b Documentation work keeps chugging along; stuff for 6.6 includes:
- Work from Carlos Bilbao to integrate rustdoc output into the generated
   HTML documentation.  This took some work to figure out how to do it
   without slowing the docs build and without creating people who don't have
   Rust installed, but Carlos got there.
 
 - Move the loongarch and mips architecture documentation under
   Documentation/arch/.
 
 - Some more maintainer documentation from Jakub
 
 ...plus the usual assortment of updates, translations, and fixes.
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Merge tag 'docs-6.6' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "Documentation work keeps chugging along; this includes:

   - Work from Carlos Bilbao to integrate rustdoc output into the
     generated HTML documentation. This took some work to figure out how
     to do it without slowing the docs build and without creating people
     who don't have Rust installed, but Carlos got there

   - Move the loongarch and mips architecture documentation under
     Documentation/arch/

   - Some more maintainer documentation from Jakub

  ... plus the usual assortment of updates, translations, and fixes"

* tag 'docs-6.6' of git://git.lwn.net/linux: (56 commits)
  Docu: genericirq.rst: fix irq-example
  input: docs: pxrc: remove reference to phoenix-sim
  Documentation: serial-console: Fix literal block marker
  docs/mm: remove references to hmm_mirror ops and clean typos
  docs/zh_CN: correct regi_chg(),regi_add() to region_chg(),region_add()
  Documentation: Fix typos
  Documentation/ABI: Fix typos
  scripts: kernel-doc: fix macro handling in enums
  scripts: kernel-doc: parse DEFINE_DMA_UNMAP_[ADDR|LEN]
  Documentation: riscv: Update boot image header since EFI stub is supported
  Documentation: riscv: Add early boot document
  Documentation: arm: Add bootargs to the table of added DT parameters
  docs: kernel-parameters: Refer to the correct bitmap function
  doc: update params of memhp_default_state=
  docs: Add book to process/kernel-docs.rst
  docs: sparse: fix invalid link addresses
  docs: vfs: clean up after the iterate() removal
  docs: Add a section on surveys to the researcher guidelines
  docs: move mips under arch
  docs: move loongarch under arch
  ...
2023-08-30 20:05:42 -07:00
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
Linus Torvalds
815c24a085 linux-kselftest-kunit-6.6-rc1
This kunit update for Linux 6.6.rc1 consists of:
 
 -- Adds support for running Rust documentation tests as KUnit tests
 -- Makes init, str, sync, types doctests compilable/testable
 -- Adds support for attributes API which include speed, modules
    attributes, ability to filter and report attributes.
 -- Adds support for marking tests slow using attributes API.
 -- Adds attributes API documentation
 -- Fixes to wild-memory-access bug in kunit_filter_suites() and
    a possible memory leak in kunit_filter_suites()
 -- Adds support for counting number of test suites in a module, list
    action to kunit test modules, and test filtering on module tests.
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Merge tag 'linux-kselftest-kunit-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kunit updates from Shuah Khan:

 - add support for running Rust documentation tests as KUnit tests

 - make init, str, sync, types doctests compilable/testable

 - add support for attributes API which include speed, modules
   attributes, ability to filter and report attributes

 - add support for marking tests slow using attributes API

 - add attributes API documentation

 - fix a wild-memory-access bug in kunit_filter_suites() and a possible
   memory leak in kunit_filter_suites()

 - add support for counting number of test suites in a module, list
   action to kunit test modules, and test filtering on module tests

* tag 'linux-kselftest-kunit-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (25 commits)
  kunit: fix struct kunit_attr header
  kunit: replace KUNIT_TRIGGER_STATIC_STUB maro with KUNIT_STATIC_STUB_REDIRECT
  kunit: Allow kunit test modules to use test filtering
  kunit: Make 'list' action available to kunit test modules
  kunit: Report the count of test suites in a module
  kunit: fix uninitialized variables bug in attributes filtering
  kunit: fix possible memory leak in kunit_filter_suites()
  kunit: fix wild-memory-access bug in kunit_filter_suites()
  kunit: Add documentation of KUnit test attributes
  kunit: add tests for filtering attributes
  kunit: time: Mark test as slow using test attributes
  kunit: memcpy: Mark tests as slow using test attributes
  kunit: tool: Add command line interface to filter and report attributes
  kunit: Add ability to filter attributes
  kunit: Add module attribute
  kunit: Add speed attribute
  kunit: Add test attributes API structure
  MAINTAINERS: add Rust KUnit files to the KUnit entry
  rust: support running Rust documentation tests as KUnit ones
  rust: types: make doctests compilable/testable
  ...
2023-08-28 18:56:38 -07:00
Martin Rodriguez Reboredo
4f353e0d12 scripts: generate_rust_analyzer: provide cfgs for core and alloc
Both `core` and `alloc` have their `cfgs` (such as `no_rc`) missing
in `rust-project.json`.

To remedy this, pass the flags to `generate_rust_analyzer.py` for
them to be added to a dictionary where each key corresponds to
a crate and each value to a list of `cfg`s. The dictionary is then
used to pass the `cfg`s to each crate in the generated file (for
`core` and `alloc` only).

Signed-off-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Link: https://lore.kernel.org/r/20230804171448.54976-1-yakoyoku@gmail.com
[ Removed `Suggested-by` as discussed in mailing list. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-20 22:54:32 +02:00
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
Miguel Ojeda
89eed1ab11 rust: upgrade to Rust 1.71.1
This is the second upgrade to the Rust toolchain, from 1.68.2 to 1.71.1
(i.e. the latest).

See the upgrade policy [1] and the comments on the first upgrade in
commit 3ed03f4da0 ("rust: upgrade to Rust 1.68.2").

# Unstable features

No unstable features (that we use) were stabilized.

Therefore, the only unstable feature allowed to be used outside
the `kernel` crate is still `new_uninit`, though other code to be
upstreamed may increase the list.

Please see [2] for details.

# Required changes

For the upgrade, this patch requires the following changes:

  - Removal of the `__rust_*` allocator functions, together with
    the addition of the `__rust_no_alloc_shim_is_unstable` static.
    See [3] for details.

  - Some more compiler builtins added due to `<f{32,64}>::midpoint()`
    that got added in Rust 1.71 [4].

# `alloc` upgrade and reviewing

The vast majority of changes are due to our `alloc` fork being upgraded
at once.

There are two kinds of changes to be aware of: the ones coming from
upstream, which we should follow as closely as possible, and the updates
needed in our added fallible APIs to keep them matching the newer
infallible APIs coming from upstream.

Instead of taking a look at the diff of this patch, an alternative
approach is reviewing a diff of the changes between upstream `alloc` and
the kernel's. This allows to easily inspect the kernel additions only,
especially to check if the fallible methods we already have still match
the infallible ones in the new version coming from upstream.

Another approach is reviewing the changes introduced in the additions in
the kernel fork between the two versions. This is useful to spot
potentially unintended changes to our additions.

To apply these approaches, one may follow steps similar to the following
to generate a pair of patches that show the differences between upstream
Rust and the kernel (for the subset of `alloc` we use) before and after
applying this patch:

    # Get the difference with respect to the old version.
    git -C rust checkout $(linux/scripts/min-tool-version.sh rustc)
    git -C linux ls-tree -r --name-only HEAD -- rust/alloc |
        cut -d/ -f3- |
        grep -Fv README.md |
        xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH
    git -C linux diff --patch-with-stat --summary -R > old.patch
    git -C linux restore rust/alloc

    # Apply this patch.
    git -C linux am rust-upgrade.patch

    # Get the difference with respect to the new version.
    git -C rust checkout $(linux/scripts/min-tool-version.sh rustc)
    git -C linux ls-tree -r --name-only HEAD -- rust/alloc |
        cut -d/ -f3- |
        grep -Fv README.md |
        xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH
    git -C linux diff --patch-with-stat --summary -R > new.patch
    git -C linux restore rust/alloc

Now one may check the `new.patch` to take a look at the additions (first
approach) or at the difference between those two patches (second
approach). For the latter, a side-by-side tool is recommended.

Link: https://rust-for-linux.com/rust-version-policy [1]
Link: https://github.com/Rust-for-Linux/linux/issues/2 [2]
Link: https://github.com/rust-lang/rust/pull/86844 [3]
Link: https://github.com/rust-lang/rust/pull/92048 [4]
Closes: https://github.com/Rust-for-Linux/linux/issues/68
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Link: https://lore.kernel.org/r/20230729220317.416771-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-14 17:50:02 +02:00
Vinay Varma
49a9ef7674 scripts: make rust-analyzer for out-of-tree modules
Adds support for out-of-tree rust modules to use the `rust-analyzer`
make target to generate the rust-project.json file.

The change involves adding an optional parameter `external_src` to the
`generate_rust_analyzer.py` which expects the path to the out-of-tree
module's source directory. When this parameter is passed, I have chosen
not to add the non-core modules (samples and drivers) into the result
since these are not expected to be used in third party modules. Related
changes are also made to the Makefile and rust/Makefile allowing the
`rust-analyzer` target to be used for out-of-tree modules as well.

Link: https://github.com/Rust-for-Linux/linux/pull/914
Link: https://github.com/Rust-for-Linux/rust-out-of-tree-module/pull/2
Signed-off-by: Vinay Varma <varmavinaym@gmail.com>
Link: https://lore.kernel.org/r/20230411091714.130525-1-varmavinaym@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-07 11:33:34 +02:00
Andrea Righi
b055448843 rust: fix bindgen build error with UBSAN_BOUNDS_STRICT
With commit 2d47c6956a ("ubsan: Tighten UBSAN_BOUNDS on GCC") if
CONFIG_UBSAN is enabled and gcc supports -fsanitize=bounds-strict, we
can trigger the following build error due to bindgen lacking support for
this additional build option:

   BINDGEN rust/bindings/bindings_generated.rs
 error: unsupported argument 'bounds-strict' to option '-fsanitize='

Fix by adding -fsanitize=bounds-strict to the list of skipped gcc flags
for bindgen.

Fixes: 2d47c6956a ("ubsan: Tighten UBSAN_BOUNDS on GCC")
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Link: https://lore.kernel.org/r/20230711071914.133946-1-andrea.righi@canonical.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-04 17:10:50 +02:00
Carlos Bilbao
48fadf4400 docs: Move rustdoc output, cross-reference it
Generate rustdoc documentation with the rest of subsystem's documentation
in Documentation/output. Add a cross reference to the generated rustdoc in
Documentation/rust/index.rst if Sphinx target rustdoc is set.

Reviewed-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Carlos Bilbao <carlos.bilbao@amd.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20230718151534.4067460-2-carlos.bilbao@amd.com
2023-07-21 15:08:46 -06:00
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
Linus Torvalds
310897659c Rust changes for v6.4
More additions to the Rust core. Importantly, this adds the pin-init
 API, which will be used by other abstractions, such as the
 synchronization ones added here too:
 
   - pin-init API: a solution for the safe pinned initialization problem.
     This allows to reduce the need for 'unsafe' code in the kernel when
     dealing with data structures that require a stable address. Commit
     90e53c5e70 ("rust: add pin-init API core") contains a nice
     introduction -- here is an example of how it looks like:
 
         #[pin_data]
         struct Example {
             #[pin]
             value: Mutex<u32>,
 
             #[pin]
             value_changed: CondVar,
         }
 
         impl Example {
             fn new() -> impl PinInit<Self> {
                 pin_init!(Self {
                     value <- new_mutex!(0),
                     value_changed <- new_condvar!(),
                 })
             }
         }
 
         // In a `Box`.
         let b = Box::pin_init(Example::new())?;
 
         // In the stack.
         stack_pin_init!(let s = Example::new());
 
   - 'sync' module: new types 'LockClassKey' ('struct lock_class_key'),
     'Lock', 'Guard', 'Mutex' ('struct mutex'), 'SpinLock'
     ('spinlock_t'), 'LockedBy' and 'CondVar' (uses 'wait_queue_head_t'),
     plus macros such as 'static_lock_class!' and 'new_spinlock!'.
 
     In particular, 'Lock' and 'Guard' are generic implementations that
     contain code that is common to all locks. Then, different backends
     (the new 'Backend' trait) are implemented and used to define types
     like 'Mutex':
 
         type Mutex<T> = Lock<T, MutexBackend>;
 
     In addition, new methods 'assume_init()', 'init_with()' and
     'pin_init_with()' for 'UniqueArc<MaybeUninit<T>>' and 'downcast()'
     for 'Arc<dyn Any + Send + Sync>'; as well as 'Debug' and 'Display'
     implementations for 'Arc' and 'UniqueArc'. Reduced stack usage of
     'UniqueArc::try_new_uninit()', too.
 
   - 'types' module: new trait 'AlwaysRefCounted' and new type 'ARef'
     (an owned reference to an always-reference-counted object, meant to
     be used in wrappers for C types that have their own ref counting
     functions).
 
     Moreover, new associated functions 'raw_get()' and 'ffi_init()'
     for 'Opaque'.
 
   - New 'task' module with a new type 'Task' ('struct task_struct'), and
     a new macro 'current!' to safely get a reference to the current one.
 
   - New 'ioctl' module with new '_IOC*' const functions (equivalent to
     the C macros).
 
   - New 'uapi' crate, intended to be accessible by drivers directly.
 
   - 'macros' crate: new 'quote!' macro (similar to the one provided in
     userspace by the 'quote' crate); and the 'module!' macro now allows
     specifying multiple module aliases.
 
   - 'error' module: new associated functions for the 'Error' type,
     such as 'from_errno()' and new functions such as 'to_result()'.
 
   - 'alloc' crate: more fallible 'Vec' methods: 'try_resize` and
     'try_extend_from_slice' and the infrastructure (imported from
     the Rust standard library) they need.
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Merge tag 'rust-6.4' of https://github.com/Rust-for-Linux/linux

Pull rust updates from Miguel Ojeda
 "More additions to the Rust core. Importantly, this adds the pin-init
  API, which will be used by other abstractions, such as the
  synchronization ones added here too:

   - pin-init API: a solution for the safe pinned initialization
     problem.

     This allows to reduce the need for 'unsafe' code in the kernel when
     dealing with data structures that require a stable address. Commit
     90e53c5e70 ("rust: add pin-init API core") contains a nice
     introduction -- here is an example of how it looks like:

        #[pin_data]
        struct Example {
            #[pin]
            value: Mutex<u32>,

            #[pin]
            value_changed: CondVar,
        }

        impl Example {
            fn new() -> impl PinInit<Self> {
                pin_init!(Self {
                    value <- new_mutex!(0),
                    value_changed <- new_condvar!(),
                })
            }
        }

        // In a `Box`.
        let b = Box::pin_init(Example::new())?;

        // In the stack.
        stack_pin_init!(let s = Example::new());

   - 'sync' module:

     New types 'LockClassKey' ('struct lock_class_key'), 'Lock',
     'Guard', 'Mutex' ('struct mutex'), 'SpinLock' ('spinlock_t'),
     'LockedBy' and 'CondVar' (uses 'wait_queue_head_t'), plus macros
     such as 'static_lock_class!' and 'new_spinlock!'.

     In particular, 'Lock' and 'Guard' are generic implementations that
     contain code that is common to all locks. Then, different backends
     (the new 'Backend' trait) are implemented and used to define types
     like 'Mutex':

        type Mutex<T> = Lock<T, MutexBackend>;

     In addition, new methods 'assume_init()', 'init_with()' and
     'pin_init_with()' for 'UniqueArc<MaybeUninit<T>>' and 'downcast()'
     for 'Arc<dyn Any + Send + Sync>'; as well as 'Debug' and 'Display'
     implementations for 'Arc' and 'UniqueArc'. Reduced stack usage of
     'UniqueArc::try_new_uninit()', too.

   - 'types' module:

     New trait 'AlwaysRefCounted' and new type 'ARef' (an owned
     reference to an always-reference-counted object, meant to be used
     in wrappers for C types that have their own ref counting
     functions).

     Moreover, new associated functions 'raw_get()' and 'ffi_init()' for
     'Opaque'.

   - New 'task' module with a new type 'Task' ('struct task_struct'),
     and a new macro 'current!' to safely get a reference to the current
     one.

   - New 'ioctl' module with new '_IOC*' const functions (equivalent to
     the C macros).

   - New 'uapi' crate, intended to be accessible by drivers directly.

   - 'macros' crate: new 'quote!' macro (similar to the one provided in
     userspace by the 'quote' crate); and the 'module!' macro now allows
     specifying multiple module aliases.

   - 'error' module:

     New associated functions for the 'Error' type, such as
     'from_errno()' and new functions such as 'to_result()'.

   - 'alloc' crate:

     More fallible 'Vec' methods: 'try_resize` and
     'try_extend_from_slice' and the infrastructure (imported from the
     Rust standard library) they need"

* tag 'rust-6.4' of https://github.com/Rust-for-Linux/linux: (44 commits)
  rust: ioctl: Add ioctl number manipulation functions
  rust: uapi: Add UAPI crate
  rust: sync: introduce `CondVar`
  rust: lock: add `Guard::do_unlocked`
  rust: sync: introduce `LockedBy`
  rust: introduce `current`
  rust: add basic `Task`
  rust: introduce `ARef`
  rust: lock: introduce `SpinLock`
  rust: lock: introduce `Mutex`
  rust: sync: introduce `Lock` and `Guard`
  rust: sync: introduce `LockClassKey`
  MAINTAINERS: add Benno Lossin as Rust reviewer
  rust: init: broaden the blanket impl of `Init`
  rust: sync: add functions for initializing `UniqueArc<MaybeUninit<T>>`
  rust: sync: reduce stack usage of `UniqueArc::try_new_uninit`
  rust: types: add `Opaque::ffi_init`
  rust: prelude: add `pin-init` API items to prelude
  rust: init: add `Zeroable` trait and `init::zeroed` function
  rust: init: add `stack_pin_init!` macro
  ...
2023-04-30 11:20:22 -07:00
Asahi Lina
4e17466568 rust: uapi: Add UAPI crate
This crate mirrors the `bindings` crate, but will contain only UAPI
bindings. Unlike the bindings crate, drivers may directly use this crate
if they have to interface with userspace.

Initially, just bind the generic ioctl stuff.

In the future, we would also like to add additional checks to ensure
that all types exposed by this crate satisfy UAPI-safety guarantees
(that is, they are safely castable to/from a "bag of bits").

[ Miguel: added support for the `rustdoc` and `rusttest` targets,
  since otherwise they fail, and we want to keep them working. ]

Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Asahi Lina <lina@asahilina.net>
Link: https://lore.kernel.org/r/20230329-rust-uapi-v2-1-bca5fb4d4a12@asahilina.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22 01:46:45 +02:00
Andrea Righi
d966c3cab9 rust: allow to use INIT_STACK_ALL_ZERO
With CONFIG_INIT_STACK_ALL_ZERO enabled, bindgen passes
-ftrivial-auto-var-init=zero to clang, that triggers the following
error:

 error: '-ftrivial-auto-var-init=zero' hasn't been enabled; enable it at your own peril for benchmarking purpose only with '-enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang'

However, this additional option that is currently required by clang is
deprecated since clang-16 and going to be removed in the future,
likely with clang-18.

So, make sure bindgen is using this extra option if the major version of
the libclang used by bindgen is < 16.

In this way we can enable CONFIG_INIT_STACK_ALL_ZERO with CONFIG_RUST
without triggering any build error.

Link: https://github.com/llvm/llvm-project/issues/44842
Link: https://github.com/llvm/llvm-project/blob/llvmorg-16.0.0-rc2/clang/docs/ReleaseNotes.rst#deprecated-compiler-flags
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
[Changed to < 16, added link and reworded]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-19 19:34:43 +02:00
Vincenzo Palazzo
1c5f054f0b rust: build: Fix grep warning
Fix grep warning during the build, with GNU grep 3.8
with the following command

`grep -v '^\#\|^$$' rust/bindgen_parameters`

I see the following warning

```
grep: warning: stray \ before #

--opaque-type xregs_state
--opaque-type desc_struct
--opaque-type arch_lbr_state
--opaque-type local_apic

--opaque-type x86_msi_data
--opaque-type x86_msi_addr_lo

--opaque-type kunit_try_catch

--opaque-type spinlock

--no-doc-comments
```

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Tested-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-07 00:53:40 +02:00
Linus Torvalds
498a1cf902 Kbuild updates for v6.3
- Change V=1 option to print both short log and full command log.
 
  - Allow V=1 and V=2 to be combined as V=12.
 
  - Make W=1 detect wrong .gitignore files.
 
  - Tree-wide cleanups for unused command line arguments passed to Clang.
 
  - Stop using -Qunused-arguments with Clang.
 
  - Make scripts/setlocalversion handle only correct release tags instead
    of any arbitrary annotated tag.
 
  - Create Debian and RPM source packages without cleaning the source tree.
 
  - Various cleanups for packaging.
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Merge tag 'kbuild-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Change V=1 option to print both short log and full command log

 - Allow V=1 and V=2 to be combined as V=12

 - Make W=1 detect wrong .gitignore files

 - Tree-wide cleanups for unused command line arguments passed to Clang

 - Stop using -Qunused-arguments with Clang

 - Make scripts/setlocalversion handle only correct release tags instead
   of any arbitrary annotated tag

 - Create Debian and RPM source packages without cleaning the source
   tree

 - Various cleanups for packaging

* tag 'kbuild-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (74 commits)
  kbuild: rpm-pkg: remove unneeded KERNELRELEASE from modules/headers_install
  docs: kbuild: remove description of KBUILD_LDS_MODULE
  .gitattributes: use 'dts' diff driver for *.dtso files
  kbuild: deb-pkg: improve the usability of source package
  kbuild: deb-pkg: fix binary-arch and clean in debian/rules
  kbuild: tar-pkg: use tar rules in scripts/Makefile.package
  kbuild: make perf-tar*-src-pkg work without relying on git
  kbuild: deb-pkg: switch over to source format 3.0 (quilt)
  kbuild: deb-pkg: make .orig tarball a hard link if possible
  kbuild: deb-pkg: hide KDEB_SOURCENAME from Makefile
  kbuild: srcrpm-pkg: create source package without cleaning
  kbuild: rpm-pkg: build binary packages from source rpm
  kbuild: deb-pkg: create source package without cleaning
  kbuild: add a tool to list files ignored by git
  Documentation/llvm: add Chimera Linux, Google and Meta datacenters
  setlocalversion: use only the correct release tag for git-describe
  setlocalversion: clean up the construction of version output
  .gitignore: ignore *.cover and *.mbx
  kbuild: remove --include-dir MAKEFLAG from top Makefile
  kbuild: fix trivial typo in comment
  ...
2023-02-26 11:53:25 -08:00
Masahiro Yamada
c83b16cefd kbuild: rust: move rust/target.json to scripts/
scripts/ is a better place to generate files used treewide.

With target.json moved to scripts/, you do not need to add target.json
to no-clean-files or MRPROPER_FILES.

'make clean' does not visit scripts/, but 'make mrproper' does.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
2023-01-22 23:43:33 +09:00
Masahiro Yamada
2185242fad kbuild: remove sed commands after rustc rules
rustc may put comments in dep-info, so sed is used to drop them before
passing it to fixdep.

Now that fixdep can remove comments, Makefiles do not need to run sed.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
2023-01-22 23:43:33 +09:00
Masahiro Yamada
295d8398c6 kbuild: specify output names separately for each emission type from rustc
In Kbuild, two different rules must not write to the same file, but
it happens when compiling rust source files.

For example, set CONFIG_SAMPLE_RUST_MINIMAL=m and run the following:

  $ make -j$(nproc) samples/rust/rust_minimal.o samples/rust/rust_minimal.rsi \
                    samples/rust/rust_minimal.s samples/rust/rust_minimal.ll
    [snip]
    RUSTC [M] samples/rust/rust_minimal.o
    RUSTC [M] samples/rust/rust_minimal.rsi
    RUSTC [M] samples/rust/rust_minimal.s
    RUSTC [M] samples/rust/rust_minimal.ll
  mv: cannot stat 'samples/rust/rust_minimal.d': No such file or directory
  make[3]: *** [scripts/Makefile.build:334: samples/rust/rust_minimal.ll] Error 1
  make[3]: *** Waiting for unfinished jobs....
  mv: cannot stat 'samples/rust/rust_minimal.d': No such file or directory
  make[3]: *** [scripts/Makefile.build:309: samples/rust/rust_minimal.o] Error 1
  mv: cannot stat 'samples/rust/rust_minimal.d': No such file or directory
  make[3]: *** [scripts/Makefile.build:326: samples/rust/rust_minimal.s] Error 1
  make[2]: *** [scripts/Makefile.build:504: samples/rust] Error 2
  make[1]: *** [scripts/Makefile.build:504: samples] Error 2
  make: *** [Makefile:2008: .] Error 2

The reason for the error is that 4 threads running in parallel renames
the same file, samples/rust/rust_minimal.d.

This does not happen when compiling C or assembly files because
-Wp,-MMD,$(depfile) explicitly specifies the dependency filepath.
$(depfile) is a unique path for each target.

Currently, rustc is only given --out-dir and --emit=<list-of-types>
So, all the rust build rules output the dep-info into the default
<CRATE_NAME>.d, which causes the path conflict.

Fortunately, the --emit option is able to specify the output path
individually, with the form --emit=<type>=<path>.

Add --emit=dep-info=$(depfile) to the common part. Also, remove the
redundant --out-dir because the output path is specified for each type.

The code gets much cleaner because we do not need to rename *.d files.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
2023-01-22 23:43:33 +09:00