user/sven/linux.git/rust, branch v6.12.40

rust: use `#[used(compiler)]` to fix build and `modpost` with Rust >= 1.89.0

2025-07-24T06:56:37Z

commit 7498159226772d66f150dd406be462d75964a366 upstream. 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 Cc: Wesley Wiser 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 Acked-by: Björn Roy Baron Link: https://lore.kernel.org/r/20250712160103.1244945-3-ojeda@kernel.org Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

rust: init: allow `dead_code` warnings for Rust >= 1.89.0

2025-07-17T16:37:14Z

Starting with Rust 1.89.0 (expected 2025-08-07), the Rust compiler may warn: error: trait `MustNotImplDrop` is never used --> rust/kernel/init/macros.rs:927:15 | 927 | trait MustNotImplDrop {} | ^^^^^^^^^^^^^^^ | ::: rust/kernel/sync/arc.rs:133:1 | 133 | #[pin_data] | ----------- in this procedural macro expansion | = note: `-D dead-code` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(dead_code)]` = note: this error originates in the macro `$crate::__pin_data` which comes from the expansion of the attribute macro `pin_data` (in Nightly builds, run with -Z macro-backtrace for more info) Thus `allow` it to clean it up. This does not happen in mainline nor 6.15.y, because there the macro was moved out of the `kernel` crate, and `dead_code` warnings are not emitted if the macro is foreign to the crate. Thus this patch is directly sent to stable and intended for 6.12.y only. Similarly, it is not needed in previous LTSs, because there the Rust version is pinned. Acked-by: Benno Lossin Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

rust: arm: fix unknown (to Clang) argument '-mno-fdpic'

2025-07-06T09:01:33Z

[ Upstream commit 977c4308ee4270cf46e2c66b37de8e04670daa0c ] 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 Closes: https://lore.kernel.org/all/CA+G9fYvOanQBYXKSg7C6EU30k8sTRC0JRPJXYu7wWK51w38QUQ@mail.gmail.com/ Suggested-by: Miguel Ojeda Acked-by: Naresh Kamboju Signed-off-by: Rudraksha Gupta 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 Signed-off-by: Sasha Levin

rust: module: place cleanup_module() in .exit.text section

2025-07-06T09:01:33Z

[ Upstream commit 249c3a0e53acefc2b06d3b3e1fc28fb2081f878d ] Place cleanup_module() in .exit.text section. Currently, cleanup_module() is likely placed in the .text section. It's inconsistent with the layout of C modules, where cleanup_module() is placed in .exit.text. [ Boqun asked for an example of how the section changed to be put in the log. Tomonori provided the following examples: C module: $ objdump -t ~/build/x86/drivers/block/loop.o|grep clean 0000000000000000 l O .exit.data 0000000000000008 __UNIQUE_ID___addressable_cleanup_module412 0000000000000000 g F .exit.text 000000000000009c cleanup_module Rust module without this patch: $ objdump -t ~/build/x86/samples/rust/rust_minimal.o|grep clean 00000000000002b0 g F .text 00000000000000c6 cleanup_module 0000000000000000 g O .exit.data 0000000000000008 _R...___UNIQUE_ID___addressable_cleanup_module Rust module with this patch: $ objdump -t ~/build/x86/samples/rust/rust_minimal.o|grep clean 0000000000000000 g F .exit.text 00000000000000c6 cleanup_module 0000000000000000 g O .exit.data 0000000000000008 _R...___UNIQUE_ID___addressable_cleanup_module - Miguel ] Signed-off-by: FUJITA Tomonori Acked-by: Jarkko Sakkinen Link: https://lore.kernel.org/r/20250308044506.14458-1-fujita.tomonori@gmail.com Signed-off-by: Miguel Ojeda Signed-off-by: Sasha Levin

rust: compile libcore with edition 2024 for 1.87+

2025-06-27T10:11:40Z

commit f4daa80d6be7d3c55ca72a8e560afc4e21f886aa upstream. 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 Closes: https://github.com/Rust-for-Linux/linux/issues/1163 Signed-off-by: Gary Guo Link: https://lore.kernel.org/r/20250517085600.2857460-1-gary@garyguo.net Signed-off-by: Miguel Ojeda [ Solved conflicts for 6.12.y backport. - Miguel ] Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

rust: alloc: add missing invariant in Vec::set_len()

2025-06-19T13:32:09Z

[ Upstream commit fb1bf1067de979c89ae33589e0466d6ce0dde204 ] When setting a new length, we have to justify that the set length represents the exact number of elements stored in the vector. Reviewed-by: Benno Lossin Reported-by: Alice Ryhl Closes: https://lore.kernel.org/rust-for-linux/20250311-iov-iter-v1-4-f6c9134ea824@google.com Fixes: 2aac4cd7dae3 ("rust: alloc: implement kernel `Vec` type") Link: https://lore.kernel.org/r/20250315154436.65065-2-dakr@kernel.org Signed-off-by: Danilo Krummrich Signed-off-by: Sasha Levin

rust: clean Rust 1.88.0's `clippy::uninlined_format_args` lint

2025-05-18T06:24:57Z

commit 211dcf77856db64c73e0c3b9ce0c624ec855daca upstream. Starting with Rust 1.88.0 (expected 2025-06-26) [1], `rustc` may move back the `uninlined_format_args` to `style` from `pedantic` (it was there waiting for rust-analyzer suppotr), and thus we will start to see lints like: warning: variables can be used directly in the `format!` string --> rust/macros/kunit.rs:105:37 | 105 | let kunit_wrapper_fn_name = format!("kunit_rust_wrapper_{}", test); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args help: change this to | 105 - let kunit_wrapper_fn_name = format!("kunit_rust_wrapper_{}", test); 105 + let kunit_wrapper_fn_name = format!("kunit_rust_wrapper_{test}"); There is even a case that is a pure removal: warning: variables can be used directly in the `format!` string --> rust/macros/module.rs:51:13 | 51 | format!("{field}={content}\0", field = field, content = content) | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args help: change this to | 51 - format!("{field}={content}\0", field = field, content = content) 51 + format!("{field}={content}\0") The lints all seem like nice cleanups, thus just apply them. We may want to disable `allow-mixed-uninlined-format-args` in the future. 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-clippy/pull/14160 [1] Acked-by: Benno Lossin Reviewed-by: Tamir Duberstein Reviewed-by: Alice Ryhl Link: https://lore.kernel.org/r/20250502140237.1659624-6-ojeda@kernel.org Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

rust: allow Rust 1.87.0's `clippy::ptr_eq` lint

2025-05-18T06:24:57Z

commit a39f3087092716f2bd531d6fdc20403c3dc2a879 upstream. Starting with Rust 1.87.0 (expected 2025-05-15) [1], Clippy may expand the `ptr_eq` lint, e.g.: error: use `core::ptr::eq` when comparing raw pointers --> rust/kernel/list.rs:438:12 | 438 | if self.first == item { | ^^^^^^^^^^^^^^^^^^ help: try: `core::ptr::eq(self.first, item)` | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ptr_eq = note: `-D clippy::ptr-eq` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(clippy::ptr_eq)]` It is expected that a PR to relax the lint will be backported [2] by the time Rust 1.87.0 releases, since the lint was considered too eager (at least by default) [3]. Thus allow the lint temporarily just in case. 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-clippy/pull/14339 [1] Link: https://github.com/rust-lang/rust-clippy/pull/14526 [2] Link: https://github.com/rust-lang/rust-clippy/issues/14525 [3] Link: https://lore.kernel.org/r/20250502140237.1659624-3-ojeda@kernel.org [ Converted to `allow`s since backport was confirmed. - Miguel ] Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

rust: clean Rust 1.88.0's `unnecessary_transmutes` lint

2025-05-18T06:24:51Z

commit 7129ea6e242b00938532537da41ddf5fa3e21471 upstream. Starting with Rust 1.88.0 (expected 2025-06-26) [1][2], `rustc` may introduce a new lint that catches unnecessary transmutes, e.g.: error: unnecessary transmute --> rust/uapi/uapi_generated.rs:23242:18 | 23242 | unsafe { ::core::mem::transmute(self._bitfield_1.get(0usize, 1u8) as u8) } | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace this with: `(self._bitfield_1.get(0usize, 1u8) as u8 == 1)` | = note: `-D unnecessary-transmutes` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(unnecessary_transmutes)]` There are a lot of them (at least 300), but luckily they are all in `bindgen`-generated code. Thus clean all up by allowing it there. Since unknown lints trigger a lint itself in older compilers, do it conditionally so that we can keep the `unknown_lints` lint enabled. 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/136083 [1] Link: https://github.com/rust-lang/rust/issues/136067 [2] Reviewed-by: Alice Ryhl Link: https://lore.kernel.org/r/20250502140237.1659624-4-ojeda@kernel.org Signed-off-by: Miguel Ojeda Signed-off-by: Greg Kroah-Hartman

rust: firmware: Use `ffi::c_char` type in `FwFunc`

2025-05-02T05:59:06Z

commit 53bd97801632c940767f4c8407c2cbdeb56b40e7 upstream. The `FwFunc` struct contains an function with a char pointer argument, for which a `*const u8` pointer was used. This is not really the "proper" type for this, so use a `*const kernel::ffi::c_char` pointer instead. This has no real functionality changes, since now `kernel::ffi::c_char` (which bindgen uses for `char`) is now a type alias to `u8` anyways, but before commit 1bae8729e50a ("rust: map `long` to `isize` and `char` to `u8`") the concrete type of `kernel::ffi::c_char` depended on the architecture (However all supported architectures at the time mapped to `i8`). This caused problems on the v6.13 tag when building for 32 bit arm (with my patches), since back then `*const i8` was used in the function argument and the function that bindgen generated used `*const core::ffi::c_char` which Rust mapped to `*const u8` on 32 bit arm. The stable v6.13.y branch does not have this issue since commit 1bae8729e50a ("rust: map `long` to `isize` and `char` to `u8`") was backported. This caused the following build error: ``` error[E0308]: mismatched types --> rust/kernel/firmware.rs:20:4 | 20 | Self(bindings::request_firmware) | ---- ^^^^^^^^^^^^^^^^^^^^^^^^^^ expected fn pointer, found fn item | | | arguments to this function are incorrect | = note: expected fn pointer `unsafe extern "C" fn(_, *const i8, _) -> _` found fn item `unsafe extern "C" fn(_, *const u8, _) -> _ {request_firmware}` note: tuple struct defined here --> rust/kernel/firmware.rs:14:8 | 14 | struct FwFunc( | ^^^^^^ error[E0308]: mismatched types --> rust/kernel/firmware.rs:24:14 | 24 | Self(bindings::firmware_request_nowarn) | ---- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected fn pointer, found fn item | | | arguments to this function are incorrect | = note: expected fn pointer `unsafe extern "C" fn(_, *const i8, _) -> _` found fn item `unsafe extern "C" fn(_, *const u8, _) -> _ {firmware_request_nowarn}` note: tuple struct defined here --> rust/kernel/firmware.rs:14:8 | 14 | struct FwFunc( | ^^^^^^ error[E0308]: mismatched types --> rust/kernel/firmware.rs:64:45 | 64 | let ret = unsafe { func.0(pfw as _, name.as_char_ptr(), dev.as_raw()) }; | ------ ^^^^^^^^^^^^^^^^^^ expected `*const i8`, found `*const u8` | | | arguments to this function are incorrect | = note: expected raw pointer `*const i8` found raw pointer `*const u8` error: aborting due to 3 previous errors ``` Fixes: de6582833db0 ("rust: add firmware abstractions") Cc: stable@vger.kernel.org Reviewed-by: Benno Lossin Signed-off-by: Christian Schrefl Acked-by: Miguel Ojeda Link: https://lore.kernel.org/r/20250413-rust_arm_fix_fw_abstaction-v3-1-8dd7c0bbcd47@gmail.com [ Add firmware prefix to commit subject. - Danilo ] Signed-off-by: Danilo Krummrich Signed-off-by: Greg Kroah-Hartman