Pull pin-init updates from Benno Lossin:
- Replace the 'Zeroable' impls for 'Option<NonZero*>' with impls of
'ZeroableOption' for 'NonZero*'.
- Improve feature gate handling for unstable features.
- Declutter the documentation of implementations of 'Zeroable' for
tuples.
- Replace uses of 'addr_of[_mut]!' with '&raw [mut]'.
* tag 'pin-init-v7.1' of https://github.com/Rust-for-Linux/linux:
rust: pin-init: replace `addr_of_mut!` with `&raw mut`
rust: pin-init: implement ZeroableOption for NonZero* integer types
rust: pin-init: doc: de-clutter documentation with fake-variadics
rust: pin-init: properly document let binding workaround
rust: pin-init: build: simplify use of nightly features
Pull timekeeping updates from Andreas Hindborg:
- Expand the example section in the 'HrTimer' documentation.
- Mark the 'ClockSource' trait as unsafe to ensure valid values for
'ktime_get()'.
- Add 'Delta::from_nanos()'.
This is a back merge since the pull request has a newer base -- we will
avoid that in the future.
And, given it is a back merge, it happens to resolve the "subtle" conflict
around '--remap-path-{prefix,scope}' that I discussed in linux-next [1],
plus a few other common conflicts. The result matches what we did for
next-20260407.
The actual diffstat (i.e. using a temporary merge of upstream first) is:
rust/kernel/time.rs | 32 ++++-
rust/kernel/time/hrtimer.rs | 336 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 362 insertions(+), 6 deletions(-)
Link: https://lore.kernel.org/linux-next/CANiq72kdxB=W3_CV1U44oOK3SssztPo2wLDZt6LP94TEO+Kj4g@mail.gmail.com/ [1]
* tag 'rust-timekeeping-for-v7.1' of https://github.com/Rust-for-Linux/linux:
hrtimer: add usage examples to documentation
rust: time: make ClockSource unsafe trait
rust/time: Add Delta::from_nanos()
A new experimental Kconfig option, `RUST_INLINE_HELPERS` is added to
allow C helpers (which were created to allow Rust to call into
inline/macro C functions without having to re-implement the logic in
Rust) to be inlined into Rust crates without performing global LTO.
If the option is enabled, the following is performed:
* For helpers, instead of compiling them to an object file to be linked
into vmlinux, they're compiled to LLVM IR bitcode. Two versions are
generated: one for built-in code (`helpers.bc`) and one for modules
(`helpers_module.bc`, with -DMODULE defined). This ensures that C
macros/inlines that behave differently for modules (e.g. static calls)
function correctly when inlined.
* When a Rust crate or object is compiled, instead of generating an
object file, LLVM bitcode is generated.
* llvm-link is invoked with --internalize to combine the helper bitcode
with the crate bitcode. This step is similar to LTO, but this is much
faster since it only needs to inline the helpers.
* clang is invoked to turn the combined bitcode into a final object file.
* Since clang may produce LLVM bitcode when LTO is enabled, and objtool
requires ELF input, $(cmd_ld_single) is invoked to ensure the object
is converted to ELF before objtool runs.
The --internalize flag tells llvm-link to treat all symbols in
helpers.bc using `internal` linkage [1]. This matches the behavior of
`clang` on `static inline` functions, and avoids exporting the symbol
from the object file.
To ensure that RUST_INLINE_HELPERS is not incompatible with BTF, we pass
the -g0 flag when building helpers. See commit 5daa0c35a1 ("rust:
Disallow BTF generation with Rust + LTO") for details.
We have an intended triple mismatch of `aarch64-unknown-none` vs
`aarch64-unknown-linux-gnu`, so we pass --suppress-warnings to llvm-link
to suppress it.
I considered adding some sort of check that KBUILD_MODNAME is not
present in helpers_module.bc, but this is actually not so easy to carry
out because .bc files store strings in a weird binary format, so you
cannot just grep it for a string to check whether it ended up using
KBUILD_MODNAME anywhere.
[ Andreas writes:
For the rnull driver, enabling helper inlining with this patch
gives an average speedup of 2% over the set of 120 workloads that
we publish on [2].
Link: https://rust-for-linux.com/null-block-driver [2]
This series also uncovered a pre-existing UB instance thanks to an
`objtool` warning which I noticed while testing the series (details
in the mailing list).
- Miguel ]
Link: https://github.com/llvm/llvm-project/pull/170397 [1]
Co-developed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Co-developed-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://patch.msgid.link/20260203-inline-helpers-v2-3-beb8547a03c9@google.com
[ Some changes, apart from the rebase:
- Added "(EXPERIMENTAL)" to Kconfig as the commit mentions.
- Added `depends on ARM64 || X86_64` and `!UML` for now, since this is
experimental, other architectures may require other changes (e.g.
the issues I mentioned in the mailing list for ARM and UML) and they
are not really tested so far. So let arch maintainers pick this up
if they think it is worth it.
- Gated the `cmd_ld_single` step also into the new mode, which also
means that any possible future `objcopy` step is done after the
translation, as expected.
- Added `.gitignore` for `.bc` with exception for existing script.
- Added `part-of-*` for helpers bitcode files as discussed, and
dropped `$(if $(filter %_module.bc,$@),-DMODULE)` since `-DMODULE`
is already there (would be duplicated otherwise).
- Moved `LLVM_LINK` to keep binutils list alphabetized.
- Fixed typo in title.
- Dropped second `cmd_ld_single` commit message paragraph.
- Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
We use some features that are already stable in later versions of Rust,
but only available as unstable features in older Rust versions that the
kernel needs to support.
Instead of checking if a feature is already stable, simply enable them
and allow the warning if the feature is already stable. This avoids the
need of hardcoding whether a feature has been stabilized at a given
version.
`#[feature(...)]` is used when cfg `USE_RUSTC_FEATURES` is enabled. The
build script automatically does this when a nightly compiler is detected
or `RUSTC_BOOTSTRAP` is set.
Signed-off-by: Gary Guo <gary@garyguo.net>
Link: 885c5d83d7
[ Added kernel build system changes to always enable USE_RUSTC_FEATURES.
Moved this commit earlier (swapped with the next one) to avoid a build
error. - Benno ]
Link: https://patch.msgid.link/20260319093542.3756606-2-lossin@kernel.org
Signed-off-by: Benno Lossin <lossin@kernel.org>
When building with an out directory (O=), absolute paths can end up in the
file name in `#[track_caller]` or the panic message. This is not desirable
as this leaks the exact path being used to build the kernel and means that
the same location can appear in two forms (relative or absolute).
This is reported by Asahi [1] and is being workaround in [2] previously to
force everything to be absolute path. Using absolute path for everything
solves the inconsistency, however it does not address the reproducibility
issue. So, fix this by remap all absolute paths to srctree to relative path
instead.
This is previously attempted in commit dbdffaf50f ("kbuild, rust: use
-fremap-path-prefix to make paths relative") but that was reverted as
remapping debug info causes some tool (e.g. objdump) to be unable to find
sources. Therefore, use `--remap-path-scope` to only remap macros but leave
debuginfo untouched. `--remap-path-scope` is only stable in Rust 1.95, so
use `rustc-option` to detect its presence. This feature has been available
as `-Zremap-path-scope` for all versions that we support; however due to
bugs in the Rust compiler, it does not work reliably until 1.94. I opted to
not enable it for 1.94 as it's just a single version that we missed.
This change can be validated by building a kernel with O=, strip debug info
on vmlinux, and then check if the absolute path exists in `strings
vmlinux`, e.g. `strings vmlinux |grep \/home`.
Reported-by: Janne Grunau <j@jannau.net>
Reported-by: Asahi Lina <lina+kernel@asahilina.net>
Closes: https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/Per-call-site.20data.20and.20lock.20class.20keys/near/572466559 [1]
Link: 54ab888788 [2]
Signed-off-by: Gary Guo <gary@garyguo.net>
Acked-by: Nicolas Schier <nsc@kernel.org> # kbuild
Link: https://patch.msgid.link/20260226152112.3222886-1-gary@kernel.org
[ Reworded for few typos. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Pull rust fixes from Miguel Ojeda:
"Toolchain and infrastructure:
- Pass '-Zunstable-options' flag required by the future Rust 1.95.0
- Fix 'objtool' warning for Rust 1.84.0
'kernel' crate:
- 'irq' module: add missing bound detected by the future Rust 1.95.0
- 'list' module: add missing 'unsafe' blocks and placeholder safety
comments to macros (an issue for future callers within the crate)
'pin-init' crate:
- Clean Clippy warning that changed behavior in the future Rust
1.95.0"
* tag 'rust-fixes-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux:
rust: list: Add unsafe blocks for container_of and safety comments
rust: pin-init: replace clippy `expect` with `allow`
rust: irq: add `'static` bounds to irq callbacks
objtool/rust: add one more `noreturn` Rust function
rust: kbuild: pass `-Zunstable-options` for Rust 1.95.0
Pull rust updates from Miguel Ojeda:
"Toolchain and infrastructure:
- Add '__rust_helper' annotation to the C helpers
This is needed to inline these helpers into Rust code
- Remove imports available via the prelude, treewide
This was possible thanks to a new lint in Klint that Gary has
implemented -- more Klint-related changes, including initial
upstream support, are coming
- Deduplicate pin-init flags
'kernel' crate:
- Add support for calling a function exactly once with the new
'do_once_lite!' macro (and 'OnceLite' type)
Based on this, add 'pr_*_once!' macros to print only once
- Add 'impl_flags!' macro for defining common bitflags operations:
impl_flags!(
/// Represents multiple permissions.
#[derive(Debug, Clone, Default, Copy, PartialEq, Eq)]
pub struct Permissions(u32);
/// Represents a single permission.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Permission {
/// Read permission.
Read = 1 << 0,
/// Write permission.
Write = 1 << 1,
/// Execute permission.
Execute = 1 << 2,
}
);
let mut f: Permissions = Permission::Read | Permission::Write;
assert!(f.contains(Permission::Read));
assert!(!f.contains(Permission::Execute));
f |= Permission::Execute;
assert!(f.contains(Permission::Execute));
let f2: Permissions = Permission::Write | Permission::Execute;
assert!((f ^ f2).contains(Permission::Read));
assert!(!(f ^ f2).contains(Permission::Write));
- 'bug' module: support 'CONFIG_DEBUG_BUGVERBOSE_DETAILED' in the
'warn_on!' macro in order to show the evaluated condition alongside
the file path:
------------[ cut here ]------------
WARNING: [val == 1] linux/samples/rust/rust_minimal.rs:27 at ...
Modules linked in: rust_minimal(+)
- Add safety module with 'unsafe_precondition_assert!' macro,
currently a wrapper for 'debug_assert!', intended to mark the
validation of safety preconditions where possible:
/// # Safety
///
/// The caller must ensure that `index` is less than `N`.
unsafe fn set_unchecked(&mut self, index: usize, value: T) {
unsafe_precondition_assert!(
index < N,
"set_unchecked() requires index ({index}) < N ({N})"
);
...
}
- Add instructions to 'build_assert!' documentation requesting to
always inline functions when used with function arguments
- 'ptr' module: replace 'build_assert!' with a 'const' one
- 'rbtree' module: reduce unsafe blocks on pointer derefs
- 'transmute' module: implement 'FromBytes' and 'AsBytes' for
inhabited ZSTs, and use it in Nova
- More treewide replacements of 'c_str!' with C string literals
'macros' crate:
- Rewrite most procedural macros ('module!', 'concat_idents!',
'#[export]', '#[vtable]', '#[kunit_tests]') to use the 'syn'
parsing library which we introduced last cycle, with better
diagnostics
This also allows to support '#[cfg]' properly in the '#[vtable]'
macro, to support arbitrary types in 'module!' macro (not just an
identifier) and to remove several custom parsing helpers we had
- Use 'quote!' from the recently vendored 'quote' library and remove
our custom one
The vendored one also allows us to avoid quoting '"' and '{}'
inside the template anymore and editors can now highlight it. In
addition, it improves robustness as it eliminates the need for
string quoting and escaping
- Use 'pin_init::zeroed()' to simplify KUnit code
'pin-init' crate:
- Rewrite all procedural macros ('[pin_]init!', '#[pin_data]',
'#[pinned_drop]', 'derive([Maybe]Zeroable)') to use the 'syn'
parsing library which we introduced last cycle, with better
diagnostics
- Implement 'InPlaceWrite' for '&'static mut MaybeUninit<T>'. This
enables users to use external allocation mechanisms such as
'static_cell'
- Support tuple structs in 'derive([Maybe]Zeroable)'
- Support attributes on fields in '[pin_]init!' (such as
'#[cfg(...)]')
- Add a '#[default_error(<type>)]' attribute to '[pin_]init!' to
override the default error (when no '? Error' is specified)
- Support packed structs in '[pin_]init!' with
'#[disable_initialized_field_access]'
- Remove 'try_[pin_]init!' in favor of merging their feature with
'[pin_]init!'. Update the kernel's own 'try_[pin_]init!' macros to
use the 'default_error' attribute
- Correct 'T: Sized' bounds to 'T: ?Sized' in the generated
'PinnedDrop' check by '#[pin_data]'
Documentation:
- Conclude the Rust experiment
MAINTAINERS:
- Add "RUST [RUST-ANALYZER]" entry for the rust-analyzer support.
Tamir and Jesung will take care of it. They have both been active
around it for a while. The new tree will flow through the Rust one
- Add Gary as maintainer for "RUST [PIN-INIT]"
- Update Boqun and Tamir emails to their kernel.org accounts
And a few other cleanups and improvements"
* tag 'rust-6.20-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (59 commits)
rust: safety: introduce `unsafe_precondition_assert!` macro
rust: add `impl_flags!` macro for defining common bitflag operations
rust: print: Add pr_*_once macros
rust: bug: Support DEBUG_BUGVERBOSE_DETAILED option
rust: print: Add support for calling a function exactly once
rust: kbuild: deduplicate pin-init flags
gpu: nova-core: remove imports available via prelude
rust: clk: replace `kernel::c_str!` with C-Strings
MAINTAINERS: Update my email address to @kernel.org
rust: macros: support `#[cfg]` properly in `#[vtable]` macro.
rust: kunit: use `pin_init::zeroed` instead of custom null value
rust: macros: rearrange `#[doc(hidden)]` in `module!` macro
rust: macros: allow arbitrary types to be used in `module!` macro
rust: macros: convert `#[kunit_tests]` macro to use `syn`
rust: macros: convert `concat_idents!` to use `syn`
rust: macros: convert `#[export]` to use `syn`
rust: macros: use `quote!` for `module!` macro
rust: macros: use `syn` to parse `module!` macro
rust: macros: convert `#[vtable]` macro to use `syn`
rust: macros: use `quote!` from vendored crate
...
Custom target specifications are unstable, but starting with Rust 1.95.0,
`rustc` requires to explicitly pass `-Zunstable-options` to use them [1]:
error: error loading target specification: custom targets are unstable and require `-Zunstable-options`
|
= help: run `rustc --print target-list` for a list of built-in targets
David (Rust compiler team lead), writes:
"We're destabilising custom targets to allow us to move forward with
build-std without accidentally exposing functionality that we'd like
to revisit prior to committing to. I'll start a thread on Zulip to
discuss with the RfL team how we can come up with an alternative
for them."
Thus pass it.
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/151534 [1]
Reviewed-by: Gary Guo <gary@garyguo.net>
Tested-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260206204535.39431-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
`syn` makes parsing Rust from proc-macros a lot simpler. `pin-init` has
not used `syn` up until now, because the we did not support it. That
changed in commit 54e3eae855 ("Merge patch series "`syn` support""),
so we can finally utilize the added ergonomics of parsing proc-macro
input with `syn`.
Previously we only had the `proc-macro` library available, whereas the
user-space version also used `proc-macro2` and `quote`. Now both are
available, so remove the workarounds.
Due to these changes, clippy emits warnings about unnecessary
`.to_string()` as `proc-macro2` provides an additional `PartialEq` impl
on `Ident`, so the warnings are fixed.
[ Adjusted wording from upstream version and added build system changes
for the kernel - Benno ]
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: Benno Lossin <lossin@kernel.org>
This got added with:
7454048db2 ("kbuild: Enable GCC diagnostic context for value-tracking warnings")
but clang does not have this option, so avoid passing it to bindgen.
[ Details about what the option does are in the commit above. Nathan
also expands on this:
Right, this does look correct, as this option is specific to GCC
for the purpose of exposing more information from GCC internals to
the user for understanding diagnostics better.
I checked that in Compiler Explorer GCC 15.2 doesn't have it, but GCC
trunk indeed has. - Miguel ]
Fixes: 7454048db2 ("kbuild: Enable GCC diagnostic context for value-tracking warnings")
Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org>
Link: https://patch.msgid.link/20251217224050.1186896-1-siddhesh@gotplt.org
[ Removed Cc: stable. Added title prefix. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Pull Rust updates from Miguel Ojeda:
"Toolchain and infrastructure:
- Add support for 'syn'.
Syn is a parsing library for parsing a stream of Rust tokens into a
syntax tree of Rust source code.
Currently this library is geared toward use in Rust procedural
macros, but contains some APIs that may be useful more generally.
'syn' allows us to greatly simplify writing complex macros such as
'pin-init' (Benno has already prepared the 'syn'-based version). We
will use it in the 'macros' crate too.
'syn' is the most downloaded Rust crate (according to crates.io),
and it is also used by the Rust compiler itself. While the amount
of code is substantial, there should not be many updates needed for
these crates, and even if there are, they should not be too big,
e.g. +7k -3k lines across the 3 crates in the last year.
'syn' requires two smaller dependencies: 'quote' and 'proc-macro2'.
I only modified their code to remove a third dependency
('unicode-ident') and to add the SPDX identifiers. The code can be
easily verified to exactly match upstream with the provided
scripts.
They are all licensed under "Apache-2.0 OR MIT", like the other
vendored 'alloc' crate we had for a while.
Please see the merge commit with the cover letter for more context.
- Allow 'unreachable_pub' and 'clippy::disallowed_names' for
doctests.
Examples (i.e. doctests) may want to do things like show public
items and use names such as 'foo'.
Nevertheless, we still try to keep examples as close to real code
as possible (this is part of why running Clippy on doctests is
important for us, e.g. for safety comments, which userspace Rust
does not support yet but we are stricter).
'kernel' crate:
- Replace our custom 'CStr' type with 'core::ffi::CStr'.
Using the standard library type reduces our custom code footprint,
and we retain needed custom functionality through an extension
trait and a new 'fmt!' macro which replaces the previous 'core'
import.
This started in 6.17 and continued in 6.18, and we finally land the
replacement now. This required quite some stamina from Tamir, who
split the changes in steps to prepare for the flag day change here.
- Replace 'kernel::c_str!' with C string literals.
C string literals were added in Rust 1.77, which produce '&CStr's
(the 'core' one), so now we can write:
c"hi"
instead of:
c_str!("hi")
- Add 'num' module for numerical features.
It includes the 'Integer' trait, implemented for all primitive
integer types.
It also includes the 'Bounded' integer wrapping type: an integer
value that requires only the 'N' least significant bits of the
wrapped type to be encoded:
// An unsigned 8-bit integer, of which only the 4 LSBs are used.
let v = Bounded::<u8, 4>:🆕:<15>();
assert_eq!(v.get(), 15);
'Bounded' is useful to e.g. enforce guarantees when working with
bitfields that have an arbitrary number of bits.
Values can also be constructed from simple non-constant expressions
or, for more complex ones, validated at runtime.
'Bounded' also comes with comparison and arithmetic operations
(with both their backing type and other 'Bounded's with a
compatible backing type), casts to change the backing type,
extending/shrinking and infallible/fallible conversions from/to
primitives as applicable.
- 'rbtree' module: add immutable cursor ('Cursor').
It enables to use just an immutable tree reference where
appropriate. The existing fully-featured mutable cursor is renamed
to 'CursorMut'.
kallsyms:
- Fix wrong "big" kernel symbol type read from procfs.
'pin-init' crate:
- A couple minor fixes (Benno asked me to pick these patches up for
him this cycle).
Documentation:
- Quick Start guide: add Debian 13 (Trixie).
Debian Stable is now able to build Linux, since Debian 13 (released
2025-08-09) packages Rust 1.85.0, which is recent enough.
We are planning to propose that the minimum supported Rust version
in Linux follows Debian Stable releases, with Debian 13 being the
first one we upgrade to, i.e. Rust 1.85.
MAINTAINERS:
- Add entry for the new 'num' module.
- Remove Alex as Rust maintainer: he hasn't had the time to
contribute for a few years now, so it is a no-op change in
practice.
And a few other cleanups and improvements"
* tag 'rust-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (53 commits)
rust: macros: support `proc-macro2`, `quote` and `syn`
rust: syn: enable support in kbuild
rust: syn: add `README.md`
rust: syn: remove `unicode-ident` dependency
rust: syn: add SPDX License Identifiers
rust: syn: import crate
rust: quote: enable support in kbuild
rust: quote: add `README.md`
rust: quote: add SPDX License Identifiers
rust: quote: import crate
rust: proc-macro2: enable support in kbuild
rust: proc-macro2: add `README.md`
rust: proc-macro2: remove `unicode_ident` dependency
rust: proc-macro2: add SPDX License Identifiers
rust: proc-macro2: import crate
rust: kbuild: support using libraries in `rustc_procmacro`
rust: kbuild: support skipping flags in `rustc_test_library`
rust: kbuild: add proc macro library support
rust: kbuild: simplify `--cfg` handling
rust: kbuild: introduce `core-flags` and `core-skip_flags`
...
We need to handle `cfg`s in both `rustc` and `rust-analyzer`, and in
future commits some of those contain double quotes, which complicates
things further.
Thus, instead of removing the `--cfg ` part in the rust-analyzer
generation script, have the `*-cfgs` variables contain just the actual
`cfg`, and use that to generate the actual flags in `*-flags`.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Tested-by: Gary Guo <gary@garyguo.net>
Tested-by: Jesung Yang <y.j3ms.n@gmail.com>
Link: https://patch.msgid.link/20251124151837.2184382-3-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
In the next commits we are introducing `*-{cfgs,skip_flags,flags}`
variables for other crates.
Thus do so here for `core`, which simplifies a bit the `Makefile`
(including the next commit) and makes it more consistent.
This means we stop passing `-Wrustdoc::unescaped_backticks` to `rustc`
and `-Wunreachable_pub` to `rustdoc`, i.e. we skip more, which is fine
since it shouldn't have an effect.
In addition, use `:=` for `core-cfgs` to make it consistent with the
upcoming additions.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Tested-by: Gary Guo <gary@garyguo.net>
Tested-by: Jesung Yang <y.j3ms.n@gmail.com>
Link: https://patch.msgid.link/20251124151837.2184382-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
It's used to work around an objtool issue since commit abb2a55722
("LoongArch: Add cflag -fno-isolate-erroneous-paths-dereference"), but
it's then passed to bindgen and cause an error because Clang does not
have this option.
Fixes: abb2a55722 ("LoongArch: Add cflag -fno-isolate-erroneous-paths-dereference")
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Mingcong Bai <jeffbai@aosc.io>
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
The `rustdoc` modifiers bug [1] was fixed in Rust 1.90.0 [2], for which
we added a workaround in commit abbf9a4494 ("rust: workaround `rustdoc`
target modifiers bug").
However, `rustdoc`'s doctest generation still has a similar issue [3],
being fixed at [4], which does not affect us because we apply the
workaround to both, and now, starting with Rust 1.91.0 (released
2025-10-30), `-Zsanitizer` is a target modifier too [5], which means we
fail with:
RUSTDOC TK rust/kernel/lib.rs
error: mixing `-Zsanitizer` will cause an ABI mismatch in crate `kernel`
--> rust/kernel/lib.rs:3:1
|
3 | //! The `kernel` crate.
| ^
|
= help: the `-Zsanitizer` flag modifies the ABI so Rust crates compiled with different values of this flag cannot be used together safely
= note: unset `-Zsanitizer` in this crate is incompatible with `-Zsanitizer=kernel-address` in dependency `core`
= help: set `-Zsanitizer=kernel-address` in this crate or unset `-Zsanitizer` in `core`
= help: if you are sure this will not cause problems, you may use `-Cunsafe-allow-abi-mismatch=sanitizer` to silence this error
A simple way around is to add the sanitizer to the list in the existing
workaround (especially if we had not started to pass the sanitizer
flags in the previous commit, since in that case that would not be
necessary). However, that still applies the workaround in more cases
than necessary.
Instead, only modify the doctests flags to ignore the check for
sanitizers, so that it is more local (and thus the compiler keeps checking
it for us in the normal `rustdoc` calls). Since the previous commit
already treated the `rustdoc` calls as kernel objects, this should allow
us in the future to easily remove this workaround when the time comes.
By the way, the `-Cunsafe-allow-abi-mismatch` flag overwrites previous
ones rather than appending, so it needs to be all done in the same flag.
Moreover, unknown modifiers are rejected, and thus we have to gate based
on the version too.
Finally, `-Zsanitizer-cfi-normalize-integers` is not affected (in Rust
1.91.0), so it is not needed in the workaround for the moment.
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/issues/144521 [1]
Link: https://github.com/rust-lang/rust/pull/144523 [2]
Link: https://github.com/rust-lang/rust/issues/146465 [3]
Link: https://github.com/rust-lang/rust/pull/148068 [4]
Link: https://github.com/rust-lang/rust/pull/138736 [5]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Justin M. Forbes <jforbes@fedoraproject.org>
Link: https://patch.msgid.link/20251102212853.1505384-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Even if normally `build_error` isn't a kernel object, it should still
be treated as such so that we pass the same flags. Similarly, `rustdoc`
targets are never kernel objects, but we need to treat them as such.
Otherwise, starting with Rust 1.91.0 (released 2025-10-30), `rustc`
will complain about missing sanitizer flags since `-Zsanitizer` is a
target modifier too [1]:
error: mixing `-Zsanitizer` will cause an ABI mismatch in crate `build_error`
--> rust/build_error.rs:3:1
|
3 | //! Build-time error.
| ^
|
= help: the `-Zsanitizer` flag modifies the ABI so Rust crates compiled with different values of this flag cannot be used together safely
= note: unset `-Zsanitizer` in this crate is incompatible with `-Zsanitizer=kernel-address` in dependency `core`
= help: set `-Zsanitizer=kernel-address` in this crate or unset `-Zsanitizer` in `core`
= help: if you are sure this will not cause problems, you may use `-Cunsafe-allow-abi-mismatch=sanitizer` to silence this error
Thus explicitly mark them as kernel objects.
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/138736 [1]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Justin M. Forbes <jforbes@fedoraproject.org>
Link: https://patch.msgid.link/20251102212853.1505384-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
`srctree/` links may point to nonexistent files, e.g. due to renames
that missed to update the files or simply because of typos.
Since they can be easily checked for validity, do so and print a warning
in the file does not exist.
This found the following cases already in-tree:
warning: srctree/ link to include/linux/blk_mq.h does not exist
warning: srctree/ link to include/linux/drm/drm_gem.h does not exist
warning: srctree/ link to include/linux/drm/drm_drv.h does not exist
warning: srctree/ link to include/linux/drm/drm_ioctl.h does not exist
warning: srctree/ link to include/linux/drm/drm_file.h does not exist
warning: srctree/ link to include/linux/drm/drm_device.h does not exist
Inspired-by: Onur Özkan <work@onurozkan.dev>
Link: https://lore.kernel.org/rust-for-linux/CANiq72=xCYA7z7_rxpzzKkkhJs6m7L_xEaLMuArVn3ZAcyeHdA@mail.gmail.com/
Reviewed-by: Onur Özkan <work@onurozkan.dev>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Tested-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Pull alloc and DMA updates from Danilo Krummrich:
Allocator:
- Provide information about the minimum alignment guarantees of
'Kmalloc', 'Vmalloc' and 'KVmalloc'.
- Take minimum alignment guarantees of allocators for
'ForeignOwnable' into account.
- Remove the 'allocator_test' incl. 'Cmalloc'.
Box:
- Implement 'Box::pin_slice()', which constructs a pinned slice of
elements.
Vec:
- Simplify KUnit test module name to 'rust_kvec'.
- Add doc-test for 'Vec::as_slice()'.
- Constify various methods.
DMA:
- Update 'ARef' and 'AlwaysRefCounted' imports.
MISC:
- Remove support for unused host '#[test]'s.
- Constify 'ArrayLayout::new_unchecked()'.
* tag 'alloc-next-v6.18-2025-09-04' of https://github.com/Rust-for-Linux/linux:
rust: alloc: remove `allocator_test`
rust: kernel: remove support for unused host `#[test]`s
rust: alloc: implement Box::pin_slice()
rust: alloc: add ARCH_KMALLOC_MINALIGN to bindgen blocklist
rust: dma: Update ARef and AlwaysRefCounted imports from sync::aref
rust: alloc: take the allocator into account for FOREIGN_ALIGN
rust: alloc: specify the minimum alignment of each allocator
rust: make `kvec::Vec` functions `const fn`
rust: make `ArrayLayout::new_unchecked` a `const fn`
rust: alloc: kvec: simplify KUnit test module name to "rust_kvec"
rust: alloc: kvec: add doc example for as_slice method
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>
`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>
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>
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
...
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>
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>
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
...
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>
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>
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>
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>
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"
...
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
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
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>
