Merge tag 'rust-fixes-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

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

- Add 'bindgen' target to make UML 32-

Merge tag 'rust-fixes-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

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

- Add 'bindgen' target to make UML 32-bit builds work with GCC

- Disable two Clippy warnings ('collapsible_{if,match}')

'pin-init' crate:

- Fix unsoundness issue that created &'static references"

* tag 'rust-fixes-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux:
rust: allow `clippy::collapsible_if` globally
rust: allow `clippy::collapsible_match` globally
rust: pin-init: fix incorrect accessor reference lifetime
rust: pin-init: internal: move alignment check to `make_field_check`
rust: arch: um: Fix building 32-bit UML with GCC

show more ...

rust: arch: um: Fix building 32-bit UML with GCC

32-bit UML builds can be configured either by setting CONFIG_64BIT=n or
with SUBARCH=i386. Both work with Rust-for-Linux when clang is the
compiler,

rust: arch: um: Fix building 32-bit UML with GCC

32-bit UML builds can be configured either by setting CONFIG_64BIT=n or
with SUBARCH=i386. Both work with Rust-for-Linux when clang is the
compiler, but when SUBARCH=i386, we don't set a bindgen target correctly if
gcc is the compiler.

Add the appropriate bindgen target configuration for i386, as is done in
Makefile.clang.

[ For reference, the errors look like:

BINDGEN rust/bindings/bindings_generated.rs
error: unsupported option '-mno-sse' for target ''
...
error: unknown target triple 'unknown'
panicked at .../bindgen-0.72.1/ir/context.rs:562:15:
libclang error; possible causes include:
...

- Miguel ]

Fixes: ab0f4cedc355 ("arch: um: rust: Add i386 support for Rust")
Signed-off-by: David Gow <david@davidgow.net>
Link: https://patch.msgid.link/20260425034125.53866-1-david@davidgow.net
[ Added space in title. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

show more ...

Merge drm/drm-fixes into drm-misc-fixes

Getting fixes and updates from v7.1-rc1.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge drm/drm-fixes into drm-misc-fixes

Tomi needs 7.0 to apply a patch from drm-misc-fixes.

Signed-off-by: Maxime Ripard <mripard@kernel.org>

Merge tag 'v7.0-rc4' into togreg

Linux 7.0-rc4

Required for the ds4422 series which is build upon;
5187e03b817c ("iio: dac: ds4424: reject -128 RAW value")

Merge 7.0-rc4 into char-misc-next

We need the char/misc/iio fixes in this branch as well to build on top
of.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge branch 'next' into for-linus

Prepare input updates for 7.1 merge window.

Merge tag 'v7.0-rc5' into next

Sync up with mainline to pull in a fix for smb compilation error.

Merge tag 'v7.0-rc3' into next

Sync up with the mainline to brig up the latest changes, specifically
changes to ALPS driver.

Merge branch 'for-7.1-printf-kunit-build' into for-linus

Merge branch 'for-7.1/core-v2' into for-linus

- fixed handling of 0-sized reports (Dmitry Torokhov)
- convert core code to __free() (Dmitry Torokhov)
- support for multiple batteries per HID device

Merge branch 'for-7.1/core-v2' into for-linus

- fixed handling of 0-sized reports (Dmitry Torokhov)
- convert core code to __free() (Dmitry Torokhov)
- support for multiple batteries per HID device (Lucas Zampieri)

show more ...

Merge tag 'rust-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

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

- Bump the minimum Rust version to 1.85.0 (

Merge tag 'rust-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

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

- Bump the minimum Rust version to 1.85.0 (and 'bindgen' to 0.71.1).

As proposed in LPC 2025 and the Maintainers Summit [1], we are
going to follow Debian Stable's Rust versions as our minimum
versions.

Debian Trixie was released on 2025-08-09 with a Rust 1.85.0 and
'bindgen' 0.71.1 toolchain, which is a fair amount of time for e.g.
kernel developers to upgrade.

Other major distributions support a Rust version that is high
enough as well, including:

+ Arch Linux.
+ Fedora Linux.
+ Gentoo Linux.
+ Nix.
+ openSUSE Slowroll and openSUSE Tumbleweed.
+ Ubuntu 25.10 and 26.04 LTS. In addition, 24.04 LTS using
their versioned packages.

The merged patch series comes with the associated cleanups and
simplifications treewide that can be performed thanks to both
bumps, as well as documentation updates.

In addition, start using 'bindgen''s '--with-attribute-custom-enum'
feature to set the 'cfi_encoding' attribute for the 'lru_status'
enum used in Binder.

Link: https://lwn.net/Articles/1050174/ [1]

- Add experimental Kconfig option ('CONFIG_RUST_INLINE_HELPERS') that
inlines C helpers into Rust.

Essentially, it performs a step similar to LTO, but just for the
helpers, i.e. very local and fast.

It relies on 'llvm-link' and its '--internalize' flag, and requires
a compatible LLVM between Clang and 'rustc' (i.e. same major
version, 'CONFIG_RUSTC_CLANG_LLVM_COMPATIBLE'). It is only enabled
for two architectures for now.

The result is a measurable speedup in different workloads that
different users have tested. For instance, for the null block
driver, it amounts to a 2%.

- Support global per-version flags.

While we already have per-version flags in many places, we didn't
have a place to set global ones that depend on the compiler
version, i.e. in 'rust_common_flags', which sometimes is needed to
e.g. tweak the lints set per version.

Use that to allow the 'clippy::precedence' lint for Rust < 1.86.0,
since it had a change in behavior.

- Support overriding the crate name and apply it to Rust Binder,
which wanted the module to be called 'rust_binder'.

- Add the remaining '__rust_helper' annotations (started in the
previous cycle).

'kernel' crate:

- Introduce the 'const_assert!' macro: a more powerful version of
'static_assert!' that can refer to generics inside functions or
implementation bodies, e.g.:

fn f<const N: usize>() {
const_assert!(N > 1);
}

fn g<T>() {
const_assert!(size_of::<T>() > 0, "T cannot be ZST");
}

In addition, reorganize our set of build-time assertion macros
('{build,const,static_assert}!') to live in the 'build_assert'
module.

Finally, improve the docs as well to clarify how these are
different from one another and how to pick the right one to use,
and their equivalence (if any) to the existing C ones for extra
clarity.

- 'sizes' module: add 'SizeConstants' trait.

This gives us typed 'SZ_*' constants (avoiding casts) for use in
device address spaces where the address width depends on the
hardware (e.g. 32-bit MMIO windows, 64-bit GPU framebuffers, etc.),
e.g.:

let gpu_heap = 14 * u64::SZ_1M;
let mmio_window = u32::SZ_16M;

- 'clk' module: implement 'Send' and 'Sync' for 'Clk' and thus
simplify the users in Tyr and PWM.

- 'ptr' module: add 'const_align_up'.

- 'str' module: improve the documentation of the 'c_str!' macro to
explain that one should only use it for non-literal cases (for the
other case we instead use C string literals, e.g. 'c"abc"').

- Disallow the use of 'CStr::{as_ptr,from_ptr}' and clean one such
use in the 'task' module.

- 'sync' module: finish the move of 'ARef' and 'AlwaysRefCounted'
outside of the 'types' module, i.e. update the last remaining
instances and finally remove the re-exports.

- 'error' module: clarify that 'from_err_ptr' can return 'Ok(NULL)',
including runtime-tested examples.

The intention is to hopefully prevent UB that assumes the result of
the function is not 'NULL' if successful. This originated from a
case of UB I noticed in 'regulator' that created a 'NonNull' on it.

Timekeeping:

- 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()'.

'pin-init' crate:

- 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]'.

rust-analyzer:

- Add type annotations to 'generate_rust_analyzer.py'.

- Add support for scripts written in Rust ('generate_rust_target.rs',
'rustdoc_test_builder.rs', 'rustdoc_test_gen.rs').

- Refactor 'generate_rust_analyzer.py' to explicitly identify host
and target crates, improve readability, and reduce duplication.

And some other fixes, cleanups and improvements"

* tag 'rust-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (79 commits)
rust: sizes: add SizeConstants trait for device address space constants
rust: kernel: update `file_with_nul` comment
rust: kbuild: allow `clippy::precedence` for Rust < 1.86.0
rust: kbuild: support global per-version flags
rust: declare cfi_encoding for lru_status
docs: rust: general-information: use real example
docs: rust: general-information: simplify Kconfig example
docs: rust: quick-start: remove GDB/Binutils mention
docs: rust: quick-start: remove Nix "unstable channel" note
docs: rust: quick-start: remove Gentoo "testing" note
docs: rust: quick-start: add Ubuntu 26.04 LTS and remove subsection title
docs: rust: quick-start: update minimum Ubuntu version
docs: rust: quick-start: update Ubuntu versioned packages
docs: rust: quick-start: openSUSE provides `rust-src` package nowadays
rust: kbuild: remove "dummy parameter" workaround for `bindgen` < 0.71.1
rust: kbuild: update `bindgen --rust-target` version and replace comment
rust: rust_is_available: remove warning for `bindgen` < 0.69.5 && libclang >= 19.1
rust: rust_is_available: remove warning for `bindgen` 0.66.[01]
rust: bump `bindgen` minimum supported version to 0.71.1 (Debian Trixie)
rust: block: update `const_refs_to_static` MSRV TODO comment
...

show more ...

Merge tag 'pin-init-v7.1' of https://github.com/Rust-for-Linux/linux into rust-next

Pull pin-init updates from Benno Lossin:

- Replace the 'Zeroable' impls for 'Option<NonZero*>' with impls of

Merge tag 'pin-init-v7.1' of https://github.com/Rust-for-Linux/linux into rust-next

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

show more ...

Merge tag 'rust-timekeeping-for-v7.1' of https://github.com/Rust-for-Linux/linux into rust-next

Pull timekeeping updates from Andreas Hindborg:

- Expand the example section in the 'HrTimer' docume

Merge tag 'rust-timekeeping-for-v7.1' of https://github.com/Rust-for-Linux/linux into rust-next

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()

show more ...

Merge patch series "rust: bump minimum Rust and `bindgen` versions"

As proposed in the past in e.g. LPC 2025 and the Maintainers Summit [1],
we are going to follow Debian Stable's Rust versions as o

Merge patch series "rust: bump minimum Rust and `bindgen` versions"

As proposed in the past in e.g. LPC 2025 and the Maintainers Summit [1],
we are going to follow Debian Stable's Rust versions as our minimum
supported version.

Debian Trixie was released with a Rust 1.85.0 toolchain [2], which it
still uses to this day [3] (i.e. no update to Rust 1.85.1).

Debian Trixie was released with `bindgen` 0.71.1, which it also still
uses to this day [4].

Debian Trixie's release happened on 2025-08-09 [5], which means that a
fair amount of time has passed since its release for kernel developers
to upgrade.

Thus bump the minimum to the new versions, i.e.

- Rust: 1.78.0 -> 1.85.0
- bindgen: 0.65.1 -> 0.71.1

There are a few main parts to the series, in this order:

- A few cleanups that can be performed before the bumps.
- The Rust bump (and its cleanups).
- The `bindgen` bump (and its cleanups).
- Documentation updates.
- The `cfi_encoding` patch, added here, which needs the bump.
- The per-version flags support and a Clippy cleanup on top.

Link: https://lwn.net/Articles/1050174/ [1]
Link: https://www.debian.org/releases/trixie/release-notes/whats-new.en.html#desktops-and-well-known-packages [2]
Link: https://packages.debian.org/trixie/rustc [3]
Link: https://packages.debian.org/trixie/bindgen [4]
Link: https://www.debian.org/releases/trixie/ [5]
Link: https://patch.msgid.link/20260405235309.418950-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

show more ...

rust: kbuild: update `bindgen --rust-target` version and replace comment

As the comment in the `Makefile` explains, previously, we needed to
limit ourselves to the list of Rust versions known by `bi

rust: kbuild: update `bindgen --rust-target` version and replace comment

As the comment in the `Makefile` explains, previously, we needed to
limit ourselves to the list of Rust versions known by `bindgen` for its
`--rust-target` option [1].

In other words, we needed to consult the versions known by the minimum
version of `bindgen` that we supported.

Now that we bumped the minimum version of `bindgen`, that limitation
does not apply anymore since `bindgen` 0.71.0 [2].

Thus replace the comment and simply write our minimum supported Rust
version there, which is much simpler.

See commit 7a5f93ea5862 ("rust: kbuild: set `bindgen`'s Rust target
version") for more details.

Link: https://rust-lang.zulipchat.com/#narrow/channel/425075-rust-for-linux/topic/rust.20version.20on.20generated.20bindings/near/484087179 [1]
Link: https://github.com/rust-lang/rust-bindgen/pull/2993 [2]
Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260405235309.418950-21-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

show more ...

rust: kbuild: remove `feature(...)`s that are now stable

Now that the Rust minimum version is 1.85.0, there is no need to enable
certain features that are stable.

Thus clean them up.

Reviewed-by:

rust: kbuild: remove `feature(...)`s that are now stable

Now that the Rust minimum version is 1.85.0, there is no need to enable
certain features that are stable.

Thus clean them up.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260405235309.418950-13-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

show more ...

rust: kbuild: remove skipping of `-Wrustdoc::unescaped_backticks`

Back in Rust 1.82.0, I cleaned the `rustdoc::unescaped_backticks` lint in
upstream Rust and added tests so that hopefully it would n

rust: kbuild: remove skipping of `-Wrustdoc::unescaped_backticks`

Back in Rust 1.82.0, I cleaned the `rustdoc::unescaped_backticks` lint in
upstream Rust and added tests so that hopefully it would not regress [1].

Thus we can remove it from our side given the Rust minimum version bump.

Link: https://github.com/rust-lang/rust/pull/128307 [1]
Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260405235309.418950-12-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

show more ...

rust: kbuild: remove `--remap-path-prefix` workarounds

Commit 8cf5b3f83614 ("Revert "kbuild, rust: use -fremap-path-prefix
to make paths relative"") removed `--remap-path-prefix` from the build
syst

rust: kbuild: remove `--remap-path-prefix` workarounds

Commit 8cf5b3f83614 ("Revert "kbuild, rust: use -fremap-path-prefix
to make paths relative"") removed `--remap-path-prefix` from the build
system, so the workarounds are not needed anymore.

Thus remove them.

Note that the flag has landed again in parallel in this cycle in
commit dda135077ecc ("rust: build: remap path to avoid absolute path"),
together with `--remap-path-scope=macro` [1]. However, they are gated on
`rustc-option-yn, --remap-path-scope=macro`, which means they are both
only passed starting with Rust 1.95.0 [2]:

`--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.

In turn, that means the workarounds removed here should not be needed
again (even with the flag added again above), since:

- `rustdoc` now recognizes the `--remap-path-prefix` flag since Rust
1.81.0 [3] (even if it is still an unstable feature [4]).

- The Internal Compiler Error [5] that the comment mentions was fixed in
Rust 1.87.0 [6]. We tested that was the case in a previous version
of this series by making the workaround conditional [7][8].

...which are both older versions than Rust 1.95.0.

We will still need to skip `--remap-path-scope` for `rustdoc` though,
since `rustdoc` does not support that one yet [4].

Link: https://github.com/rust-lang/rust/issues/111540 [1]
Link: https://github.com/rust-lang/rust/pull/147611 [2]
Link: https://github.com/rust-lang/rust/pull/107099 [3]
Link: https://doc.rust-lang.org/nightly/rustdoc/unstable-features.html#--remap-path-prefix-remap-source-code-paths-in-output [4]
Link: https://github.com/rust-lang/rust/issues/138520 [5]
Link: https://github.com/rust-lang/rust/pull/138556 [6]
Link: https://lore.kernel.org/rust-for-linux/20260401114540.30108-9-ojeda@kernel.org/ [7]
Link: https://lore.kernel.org/rust-for-linux/20260401114540.30108-10-ojeda@kernel.org/ [8]
Link: https://patch.msgid.link/20260405235309.418950-2-ojeda@kernel.org
Acked-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

show more ...

Merge tag 'v7.0-rc6' into irq/core

to be able to merge the hyper-v patch related to randomness.

Merge tag 'rust-analyzer-v7.1' of https://github.com/Rust-for-Linux/linux into rust-next

Pull rust-analyzer updates from Tamir Duberstein:

- Add type annotations to 'generate_rust_analyzer.py'.

Merge tag 'rust-analyzer-v7.1' of https://github.com/Rust-for-Linux/linux into rust-next

Pull rust-analyzer updates from Tamir Duberstein:

- Add type annotations to 'generate_rust_analyzer.py'.

- Add support for scripts written in Rust ('generate_rust_target.rs',
'rustdoc_test_builder.rs', 'rustdoc_test_gen.rs').

- Refactor 'generate_rust_analyzer.py' to explicitly identify host and
target crates, improve readability, and reduce duplication.

* tag 'rust-analyzer-v7.1' of https://github.com/Rust-for-Linux/linux:
scripts: generate_rust_analyzer.py: reduce cfg plumbing
scripts: generate_rust_analyzer.py: rename cfg to generated_cfg
scripts: generate_rust_analyzer.py: avoid FD leak
scripts: generate_rust_analyzer.py: define scripts
scripts: generate_rust_analyzer.py: identify crates explicitly
scripts: generate_rust_analyzer.py: add type hints
scripts: generate_rust_analyzer.py: drop `"is_proc_macro": false`
scripts: generate_rust_analyzer.py: extract `{build,register}_crate`

show more ...

Merge branch 'for-linus' into for-next

Pull 7.0 devel branch for further cleanups of ctxfi driver & co.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

Merge branch 'master' into rdma-next

Let's bring v7.0-rc6 to the -next branch, so we can merge the DMA
attributes fix [1] without merge conflicts.

[1] https://lore.kernel.org/all/20260323-umem-dma-

Merge branch 'master' into rdma-next

Let's bring v7.0-rc6 to the -next branch, so we can merge the DMA
attributes fix [1] without merge conflicts.

[1] https://lore.kernel.org/all/20260323-umem-dma-attrs-v1-1-d6890f2e6a1e@nvidia.com

Signed-off-by: Leon Romanovsky <leon@kernel.org>

* master: (1688 commits)
Linux 7.0-rc6
...

show more ...

Merge drm/drm-fixes into drm-misc-next-fixes

Boris needs 7.0-rc6 for a shmem helper fix.

Signed-off-by: Maxime Ripard <mripard@kernel.org>

kbuild: rust: provide an option to inline C helpers into Rust

A new experimental Kconfig option, `RUST_INLINE_HELPERS` is added to
allow C helpers (which were created to allow Rust to call into
inli

kbuild: rust: provide an option to inline C helpers into Rust

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 5daa0c35a1f0 ("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>

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