lwn.git/Makefile, branch master

Merge tag 'kbuild-7.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux

2026-04-14T16:18:40+00:00

Pull Kbuild/Kconfig updates from Nicolas Schier: "Kbuild: - reject unexpected values for LLVM= - uapi: remove usage of toolchain headers - switch from '-fms-extensions' to '-fms-anonymous-structs' when available (currently: clang >= 23.0.0) - reduce the number of compiler-generated suffixes for clang thin-lto build - reduce output spam ("GEN Makefile") when building out of tree - improve portability for testing headers - also test UAPI headers against C++ compilers - drop build ID architecture allow-list in vdso_install - only run checksyscalls when necessary - update the debug information notes in reproducible-builds.rst - expand inlining hints with -fdiagnostics-show-inlining-chain Kconfig: - forbid multiple entries with the same symbol in a choice - error out on duplicated kconfig inclusion" * tag 'kbuild-7.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: (35 commits) kbuild: expand inlining hints with -fdiagnostics-show-inlining-chain kconfig: forbid multiple entries with the same symbol in a choice Documentation: kbuild: Update the debug information notes in reproducible-builds.rst checksyscalls: move instance functionality into generic code checksyscalls: only run when necessary checksyscalls: fail on all intermediate errors checksyscalls: move path to reference table to a variable kbuild: vdso_install: drop build ID architecture allow-list kbuild: vdso_install: gracefully handle images without build ID kbuild: vdso_install: hide readelf warnings kbuild: vdso_install: split out the readelf invocation kbuild: uapi: also test UAPI headers against C++ compilers kbuild: uapi: provide a C++ compatible dummy definition of NULL kbuild: uapi: handle UML in architecture-specific exclusion lists kbuild: uapi: move all include path flags together kbuild: uapi: move some compiler arguments out of the command definition check-uapi: use dummy libc includes check-uapi: honor ${CROSS_COMPILE} setting check-uapi: link into shared objects kbuild: reduce output spam when building out of tree ...

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

2026-04-13T16:54:20+00:00

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_assert!(N > 1); } fn g() { const_assert!(size_of::() > 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' 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 ...

Linux 7.0

2026-04-12T20:48:06+00:00

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

2026-04-08T08:44:11+00:00

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()

kbuild: expand inlining hints with -fdiagnostics-show-inlining-chain

2026-04-07T19:48:44+00:00

Clang recently added -fdiagnostics-show-inlining-chain [1] to improve the visibility of inlining chains in diagnostics. This is particularly useful for CONFIG_FORTIFY_SOURCE where detections can happen deep in inlined functions. Add this flag to KBUILD_CFLAGS under a cc-option so it is enabled if the compiler supports it. Note that GCC does not have an equivalent flag as it supports a similar diagnostic structure unconditionally. Link: https://github.com/llvm/llvm-project/pull/174892 [1] Link: https://github.com/ClangBuiltLinux/linux/issues/1571 Signed-off-by: Justin Stitt Reviewed-by: Nathan Chancellor Reviewed-by: Kees Cook Link: https://patch.msgid.link/20260330-kbuild-show-inlining-v2-1-c0c481a4ea7b@google.com Signed-off-by: Nicolas Schier

rust: kbuild: allow `clippy::precedence` for Rust < 1.86.0

2026-04-07T08:00:25+00:00

The Clippy `precedence` lint was extended in Rust 1.85.0 to include bitmasking and shift operations [1]. However, because it generated many hits, in Rust 1.86.0 it was split into a new `precedence_bits` lint which is not enabled by default [2]. In other words, only Rust 1.85 has a different behavior. For instance, it reports: warning: operator precedence can trip the unwary --> drivers/gpu/nova-core/fb/hal/ga100.rs:16:5 | 16 | / u64::from(regs::NV_PFB_NISO_FLUSH_SYSMEM_ADDR::read(bar).adr_39_08()) << FLUSH_SYSMEM_ADDR_SHIFT 17 | | | u64::from(regs::NV_PFB_NISO_FLUSH_SYSMEM_ADDR_HI::read(bar).adr_63_40()) 18 | | << FLUSH_SYSMEM_ADDR_SHIFT_HI | |_________________________________________^ | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#precedence = note: `-W clippy::precedence` implied by `-W clippy::all` = help: to override `-W clippy::all` add `#[allow(clippy::precedence)]` help: consider parenthesizing your expression | 16 ~ (u64::from(regs::NV_PFB_NISO_FLUSH_SYSMEM_ADDR::read(bar).adr_39_08()) << FLUSH_SYSMEM_ADDR_SHIFT) | (u64::from(regs::NV_PFB_NISO_FLUSH_SYSMEM_ADDR_HI::read(bar).adr_63_40()) 17 + << FLUSH_SYSMEM_ADDR_SHIFT_HI) | While so far we try our best to keep all versions Clippy-clean, the minimum (which is now Rust 1.85.0 after the bump) and the latest stable are the most important ones; and this may be considered a "false positive" with respect to the behavior in other versions. Thus allow this lint for this version using the per-version flags mechanism introduced in the previous commit. Link: https://github.com/rust-lang/rust-clippy/issues/14097 [1] Link: https://github.com/rust-lang/rust-clippy/pull/14115 [2] Link: https://lore.kernel.org/rust-for-linux/DFVDKMMA7KPC.2DN0951H3H55Y@kernel.org/ Reviewed-by: Tamir Duberstein Reviewed-by: Gary Guo Link: https://patch.msgid.link/20260405235309.418950-34-ojeda@kernel.org [ Added paragraph from commit message to comment. - Miguel ] Signed-off-by: Miguel Ojeda

rust: kbuild: support global per-version flags

2026-04-07T08:00:25+00:00

Sometimes it is useful to gate global Rust flags per compiler version. For instance, we may want to disable a lint that has false positives in a single version [1]. We already had helpers like `rustc-min-version` for that, which we use elsewhere, but we cannot currently use them for `rust_common_flags`, which contains the global flags for all Rust code (kernel and host), because `rustc-min-version` depends on `CONFIG_RUSTC_VERSION`, which does not exist when `rust_common_flags` is defined. Thus, to support that, introduce `rust_common_flags_per_version`, defined after the `include/config/auto.conf` inclusion (where `CONFIG_RUSTC_VERSION` becomes available), and append it to `rust_common_flags`, `KBUILD_HOSTRUSTFLAGS` and `KBUILD_RUSTFLAGS`. In addition, move the expansion of `HOSTRUSTFLAGS` to the same place, so that users can also override per-version flags [2]. Link: https://lore.kernel.org/rust-for-linux/CANiq72mWdFU11GcCZRchzhy0Gi1QZShvZtyRkHV2O+WA2uTdVQ@mail.gmail.com/ [1] Link: https://lore.kernel.org/rust-for-linux/CANiq72mTaA2tjhkLKf0-2hrrrt9rxWPgy6SfNSbponbGOegQvA@mail.gmail.com/ [2] Link: https://patch.msgid.link/20260307170929.153892-1-ojeda@kernel.org Link: https://patch.msgid.link/20260405235309.418950-33-ojeda@kernel.org Reviewed-by: Tamir Duberstein Signed-off-by: Miguel Ojeda

rust: allow globally `clippy::incompatible_msrv`

2026-04-07T07:54:57+00:00

`clippy::incompatible_msrv` is not buying us much, and we discussed allowing it several times in the past. For instance, there was recently another patch sent to `allow` it where needed [1]. While that particular case would not be needed after the minimum version bump to 1.85.0, it is simpler to just allow it to prevent future instances. [ In addition, the lint fired without taking into account the features that have been enabled in a crate [2]. While this was improved in Rust 1.90.0 [3], it would still fire in a case like this patch. ] Thus do so, and remove the last instance of locally allowing it we have in the tree (except the one in the vendored `proc_macro2` crate). Note that we still keep the `msrv` config option in `clippy.toml` since that affects other lints as well. Link: https://lore.kernel.org/rust-for-linux/20260404212831.78971-4-jhubbard@nvidia.com/ [1] Link: https://github.com/rust-lang/rust-clippy/issues/14425 [2] Link: https://github.com/rust-lang/rust-clippy/pull/14433 [3] Link: https://patch.msgid.link/20260405235309.418950-8-ojeda@kernel.org Reviewed-by: Gary Guo Reviewed-by: Tamir Duberstein Signed-off-by: Miguel Ojeda

Linux 7.0-rc7

2026-04-05T22:26:23+00:00

kbuild: rust: allow `clippy::uninlined_format_args`

2026-04-03T09:57:35+00:00

Clippy in Rust 1.88.0 (only) reports [1]: warning: variables can be used directly in the `format!` string --> rust/macros/module.rs:112:23 | 112 | let content = format!("{param}:{content}", param = param, content = content); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args = note: `-W clippy::uninlined-format-args` implied by `-W clippy::all` = help: to override `-W clippy::all` add `#[allow(clippy::uninlined_format_args)]` help: change this to | 112 - let content = format!("{param}:{content}", param = param, content = content); 112 + let content = format!("{param}:{content}"); warning: variables can be used directly in the `format!` string --> rust/macros/module.rs:198:14 | 198 | t => panic!("Unsupported parameter type {}", t), | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args = note: `-W clippy::uninlined-format-args` implied by `-W clippy::all` = help: to override `-W clippy::all` add `#[allow(clippy::uninlined_format_args)]` help: change this to | 198 - t => panic!("Unsupported parameter type {}", t), 198 + t => panic!("Unsupported parameter type {t}"), | The reason it only triggers in that version is that the lint was moved from `pedantic` to `style` in Rust 1.88.0 and then back to `pedantic` in Rust 1.89.0 [2][3]. In the first case, the suggestion is fair and a pure simplification, thus we will clean it up separately. To keep the behavior the same across all versions, and since the lint does not work for all macros (e.g. custom ones like `pr_info!`), disable it globally. Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs). Link: https://lore.kernel.org/rust-for-linux/CANiq72=drAtf3y_DZ-2o4jb6Az9J3Yj4QYwWnbRui4sm4AJD3Q@mail.gmail.com/ [1] Link: https://github.com/rust-lang/rust-clippy/pull/15287 [2] Link: https://github.com/rust-lang/rust-clippy/issues/15151 [3] Link: https://patch.msgid.link/20260331205849.498295-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda