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 <ojeda@kernel.org>
Currently you cannot filter out the crate-name argument
RUSTFLAGS_REMOVE_stem.o because the Rust filter-out invocation does not
include that particular argument. Since --crate-name is an argument that
can't be passed multiple times, this means that it's currently not
possible to override the crate name. Thus, remove the --crate-name
argument for drivers. This allows them to override the crate name using
the #![crate_name] annotation.
This affects symbol names, but has no effect on the filenames of object
files and other things generated by the build, as we always use --emit
with a fixed output filename.
The --crate-name argument is kept for the crates under rust/ for
simplicity and to avoid changing many of them by adding #![crate_name].
The rust analyzer script is updated to use rustc to obtain the crate
name of the driver crates, which picks up the right name whether it is
configured via #![crate_name] or not. For readability, the logic to
invoke 'rustc' is extracted to its own function.
Note that the crate name in the python script is not actually that
important - the only place where the name actually affects anything is
in the 'deps' array which specifies an index and name for each
dependency, and determines what that dependency is called in *this*
crate. (The same crate may be called different things in each
dependency.) Since driver crates are leaf crates, this doesn't apply and
the rustc invocation only affects the 'display_name' parameter.
Acked-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Jesung Yang <y.jems.n@gmail.com>
Acked-by: Tamir Duberstein <tamird@kernel.org>
Link: https://patch.msgid.link/20260402-binder-crate-name-v4-1-ec3919b87909@google.com
[ Applied Python type hints. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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>
Because of LLVM inling checks, it's generally not possible to inline a C
helper into Rust code, even with LTO:
* LLVM doesn't want to inline functions compiled with
`-fno-delete-null-pointer-checks` with code compiled without. The C
CGUs all have this enabled and Rust CGUs don't. Inlining is okay since
this is one of the hardening features that does not change the ABI,
and we shouldn't have null pointer dereferences in these helpers.
* LLVM doesn't want to inline functions with different list of builtins. C
side has `-fno-builtin-wcslen`; `wcslen` is not a Rust builtin, so
they should be compatible, but LLVM does not perform inlining due to
attributes mismatch.
* clang and Rust doesn't have the exact target string. Clang generates
`+cmov,+cx8,+fxsr` but Rust doesn't enable them (in fact, Rust will
complain if `-Ctarget-feature=+cmov,+cx8,+fxsr` is used). x86-64
always enable these features, so they are in fact the same target
string, but LLVM doesn't understand this and so inlining is inhibited.
This can be bypassed with `--ignore-tti-inline-compatible`, but this
is a hidden option.
To fix this, we can add __always_inline on every helper, which skips
these LLVM inlining checks. For this purpose, introduce a new
__rust_helper macro that needs to be added to every helper.
Most helpers already have __rust_helper specified, but there are a few
missing. The only consequence of this is that those specific helpers do
not get inlined.
Signed-off-by: Gary Guo <gary@garyguo.net>
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-v2-2-beb8547a03c9@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add a detailed comparison and recommendation of the three types of
build-time assertion macro as module documentation (and un-hide the module
to render them).
The documentation on the macro themselves are simplified to only cover the
scenarios where they should be used; links to the module documentation is
added instead.
Reviewed-by: Yury Norov <ynorov@nvidia.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Link: https://patch.msgid.link/20260319121653.2975748-4-gary@kernel.org
[ Added periods on comments. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The macro is a more powerful version of `static_assert!` for use inside
function contexts. This is powered by inline consts, so enable the feature
for old compiler versions that does not have it stably.
While it is possible already to write `const { assert!(...) }`, this
provides a short hand that is more uniform with other assertions. It also
formats nicer with rustfmt where it will not be formatted into multiple
lines.
Two users that would route via the Rust tree are converted.
Reviewed-by: Yury Norov <ynorov@nvidia.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Link: https://patch.msgid.link/20260319121653.2975748-3-gary@kernel.org
[ Rebased. Fixed period typo. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Due to Rust macro scoping rules, all macros defined in a crate using
`#[macro_export]` end up in the top-level. For the list macros, we
re-export them inside the list module, and expect users to use
`kernel::list::macro_name!()`.
Use `#[doc(hidden)]` on the macro definition, and use `#[doc(inline)]` on
the re-export to make the macro appear to be defined at module-level inside
documentation.
The other exported types are already automatically `#[doc(inline)]` because
they are defined in a non-public module, so there is no need to split the
macro re-exports out.
Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260312174700.4016015-1-gary@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
As kernel always use unsigned char and not the platform ABI's default, an
user should always use `as_char_ptr` provided via `CStrExt` instead.
Therefore configure `disallow-methods` feature of clippy to catch incorrect
usage.
Similarly, the dual `from_ptr` is also disallowed.
[ As an example, without the previous commit, we would get a warning like:
warning: use of a disallowed method `core::ffi::CStr::as_ptr`
--> rust/kernel/task.rs:422:54
|
422 | unsafe { crate::bindings::__might_sleep(file.as_ptr().cast(), loc.line() as i32) }
| ^^^^^^ help: kernel's `char` is always unsigned, use `as_char_ptr` instead: `kernel::prelude::CStrExt::as_char_ptr`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.94.0/index.html#disallowed_methods
= note: `-W clippy::disallowed-methods` implied by `-W clippy::all`
= help: to override `-W clippy::all` add `#[allow(clippy::disallowed_methods)]`
- Miguel ]
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Link: https://patch.msgid.link/20260203130745.868762-2-gary@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Python type hints allow static analysis tools like mypy to detect type
errors during development, improving the developer experience.
Python type hints have been present in the kernel since 2019 at the
latest; see commit 6ebf5866f2 ("kunit: tool: add Python wrappers for
running KUnit tests").
Add a subclass of `argparse.Namespace` to get type checking on the CLI
arguments.
Run `mypy --strict scripts/generate_rust_analyzer.py --python-version
3.9` to verify. Note that `mypy` no longer supports python < 3.9.
Tested-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Jesung Yang <y.j3ms.n@gmail.com>
Tested-by: Jesung Yang <y.j3ms.n@gmail.com>
Link: https://patch.msgid.link/20260122-rust-analyzer-types-v1-3-29cc2e91dcd5@kernel.org
Signed-off-by: Tamir Duberstein <tamird@kernel.org>
Pull EFI fix from Ard Biesheuvel:
"Fix for the x86 EFI workaround keeping boot services code and data
regions reserved until after SetVirtualAddressMap() completes:
deferred struct page initialization may result in some of this memory
being lost permanently"
* tag 'efi-fixes-for-v7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
x86/efi: defer freeing of boot services memory
Pull i2c fix from Wolfram Sang:
"A revert for the i801 driver restoring old locking behaviour"
* tag 'i2c-for-7.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: i801: Revert "i2c: i801: replace acpi_lock with I2C bus lock"
Pull x86 fixes from Ingo Molnar:
- Fix SEV guest boot failures in certain circumstances, due to
very early code relying on a BSS-zeroed variable that isn't
actually zeroed yet an may contain non-zero bootup values
Move the variable into the .data section go gain even earlier
zeroing
- Expose & allow the IBPB-on-Entry feature on SNP guests, which
was not properly exposed to guests due to initial implementational
caution
- Fix O= build failure when CONFIG_EFI_SBAT_FILE is using relative
file paths
- Fix the various SNC (Sub-NUMA Clustering) topology enumeration
bugs/artifacts (sched-domain build errors mostly).
SNC enumeration data got more complicated with Granite Rapids X
(GNR) and Clearwater Forest X (CWF), which exposed these bugs
and made their effects more serious
- Also use the now sane(r) SNC code to fix resctrl SNC detection bugs
- Work around a historic libgcc unwinder bug in the vdso32 sigreturn
code (again), which regressed during an overly aggressive recent
cleanup of DWARF annotations
* tag 'x86-urgent-2026-03-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/entry/vdso32: Work around libgcc unwinder bug
x86/resctrl: Fix SNC detection
x86/topo: Fix SNC topology mess
x86/topo: Replace x86_has_numa_in_package
x86/topo: Add topology_num_nodes_per_package()
x86/numa: Store extra copy of numa_nodes_parsed
x86/boot: Handle relative CONFIG_EFI_SBAT_FILE file paths
x86/sev: Allow IBPB-on-Entry feature for SNP guests
x86/boot/sev: Move SEV decompressor variables into the .data section
Pull timer fix from Ingo Molnar:
"Make clock_adjtime() syscall timex validation slightly more permissive
for auxiliary clocks, to not reject syscalls based on the status field
that do not try to modify the status field.
This makes the ABI behavior in clock_adjtime() consistent with
CLOCK_REALTIME"
* tag 'timers-urgent-2026-03-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timekeeping: Fix timex status validation for auxiliary clocks
Pull scheduler fix from Ingo Molnar:
"Fix a DL scheduler bug that may corrupt internal metrics during PI and
setscheduler() syscalls, resulting in kernel warnings and misbehavior.
Found during stress-testing"
* tag 'sched-urgent-2026-03-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/deadline: Fix missing ENQUEUE_REPLENISH during PI de-boosting
Pull SCSI fixes from James Bottomley:
"Two core changes and the rest in drivers, one core change to quirk the
behaviour of the Iomega Zip drive and one to fix a hang caused by tag
reallocation problems, which has mostly been seen by the iscsi client.
Note the latter fixes the problem but still has a slight sysfs memory
leak, so will be amended in the next pull request (once we've run the
fix for the fix through our testing)"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: target: Fix recursive locking in __configfs_open_file()
scsi: devinfo: Add BLIST_SKIP_IO_HINTS for Iomega ZIP
scsi: mpi3mr: Clear reset history on ready and recheck state after timeout
scsi: core: Fix refcount leak for tagset_refcnt
Pull fbdev fix from Helge Deller:
"Silence build error in au1100fb driver found by kernel test robot"
* tag 'fbdev-for-7.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev:
fbdev: au1100fb: Fix build on MIPS64
Pull parisc fixes from Helge Deller:
"While testing Sasha Levin's 'kallsyms: embed source file:line info in
kernel stack traces' patch series, which increases the typical kernel
image size, I found some issues with the parisc initial kernel mapping
which may prevent the kernel to boot.
The three small patches here fix this"
* tag 'parisc-for-7.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Fix initial page table creation for boot
parisc: Check kernel mapping earlier at bootup
parisc: Increase initial mapping to 64 MB with KALLSYMS
Pull RCU selftest fixes from Boqun Feng:
"Fix a regression in RCU torture test pre-defined scenarios caused by
commit 7dadeaa6e8 ("sched: Further restrict the preemption modes")
which limits PREEMPT_NONE to architectures that do not support
preemption at all and PREEMPT_VOLUNTARY to those architectures that do
not yet have PREEMPT_LAZY support.
Since major architectures (e.g. x86 and arm64) no longer support
CONFIG_PREEMPT_NONE and CONFIG_PREEMPT_VOLUNTARY, using them in
rcutorture, rcuscale, refscale, and scftorture pre-defined scenarios
causes config checking errors.
Switch these kconfigs to PREEMPT_LAZY"
* tag 'rcu-fixes.v7.0-20260307a' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux:
scftorture: Update due to x86 not supporting none/voluntary preemption
refscale: Update due to x86 not supporting none/voluntary preemption
rcuscale: Update due to x86 not supporting none/voluntary preemption
rcutorture: Update due to x86 not supporting none/voluntary preemption
