[PATCH 00/33] rust: bump minimum Rust and `bindgen` versions

[PATCH 00/33] rust: bump minimum Rust and `bindgen` versions

[Miguel Ojeda]

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:

  - The Rust bump (and cleanups).
  - The bindgen bump (and 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]
---
The cleanups should cover most of it -- there may be more we can do
later e.g. in linux-next.

Most patches are optional, so if there are concerns with any, they can
be dropped or be done later. Most are straightforward, though, and e.g.
a couple of them update TODO comments to keep the series even simpler.

The patches have been split as much as possible to be able to add as
much context as possible and to make it easier to review and to drop any
if needed.

All in all, it is a nice `--stat` of deletions I think :)

Alice Ryhl (1):
  rust: declare cfi_encoding for lru_status

Miguel Ojeda (32):
  rust: bump Rust minimum supported version to 1.85.0 (Debian Trixie)
  rust: bump Clippy's MSRV and clean `incompatible_msrv` allows
  rust: simplify `RUSTC_VERSION` Kconfig conditions
  rust: remove `RUSTC_HAS_SLICE_AS_FLATTENED` and simplify code
  rust: remove `RUSTC_HAS_COERCE_POINTEE` and simplify code
  rust: kbuild: remove skipping of `-Wrustdoc::unescaped_backticks`
  rust: kbuild: remove `feature(...)`s that are now stable
  rust: kbuild: simplify `--remap-path-prefix` workaround
  rust: kbuild: make `--remap-path-prefix` workaround conditional
  rust: transmute: simplify code with Rust 1.80.0 `split_at_*checked()`
  rust: alloc: simplify with `NonNull::add()` now that it is stable
  rust: macros: update `extract_if` MSRV TODO comment
  rust: block: update `const_refs_to_static` MSRV TODO comment
  rust: bump `bindgen` minimum supported version to 0.71.1 (Debian
    Trixie)
  rust: rust_is_available: remove warning for 0.66.[01] buggy versions
  rust: rust_is_available: remove warning for < 0.69.5 && libclang >=
    19.1
  rust: kbuild: update `bindgen --rust-target` version and replace
    comment
  rust: kbuild: remove "dummy parameter" workaround for `bindgen` <
    0.71.1
  rust: kbuild: remove "`try` keyword" workaround for `bindgen` < 0.59.2
  rust: kbuild: remove unneeded old `allow`s for generated layout tests
  gpu: nova-core: bindings: remove unneeded `cfg_attr`
  docs: rust: quick-start: openSUSE provides `rust-src` package nowadays
  docs: rust: quick-start: update Ubuntu versioned packages
  docs: rust: quick-start: update minimum Ubuntu version
  docs: rust: quick-start: add Ubuntu 26.04 LTS and remove subsection
    title
  docs: rust: quick-start: remove Gentoo "testing" note
  docs: rust: quick-start: remove Nix "unstable channel" note
  docs: rust: quick-start: remove GDB/Binutils mention
  docs: rust: general-information: simplify Kconfig example
  docs: rust: general-information: use real example
  rust: kbuild: support global per-version flags
  rust: kbuild: allow `clippy::precedence` for Rust < 1.86.0

 .clippy.toml                                  |  2 +-
 Documentation/process/changes.rst             |  4 +-
 Documentation/rust/general-information.rst    |  4 +-
 Documentation/rust/quick-start.rst            | 52 +++++++----------
 Makefile                                      |  9 +++
 arch/Kconfig                                  |  3 +-
 arch/arm64/Kconfig                            |  8 ---
 arch/riscv/Kconfig                            |  3 -
 drivers/android/binder/Makefile               |  3 +-
 drivers/android/binder/page_range.rs          |  6 +-
 drivers/android/binder/page_range_helper.c    | 24 --------
 drivers/android/binder/page_range_helper.h    | 15 -----
 drivers/gpu/nova-core/gsp/cmdq.rs             |  6 +-
 drivers/gpu/nova-core/gsp/fw/r570_144.rs      |  3 -
 init/Kconfig                                  | 15 +----
 rust/Makefile                                 | 36 ++++--------
 rust/bindgen_parameters                       |  8 +--
 rust/bindings/bindings_helper.h               |  1 -
 rust/bindings/lib.rs                          |  5 +-
 rust/kernel/alloc/allocator/iter.rs           |  8 +--
 rust/kernel/alloc/kbox.rs                     | 29 +---------
 rust/kernel/block/mq/gen_disk.rs              |  4 +-
 rust/kernel/lib.rs                            | 30 +---------
 rust/kernel/list/arc.rs                       | 22 +------
 rust/kernel/prelude.rs                        |  3 -
 rust/kernel/ptr.rs                            |  1 -
 rust/kernel/slice.rs                          | 49 ----------------
 rust/kernel/sync/arc.rs                       | 21 +------
 rust/kernel/transmute.rs                      | 35 ++---------
 rust/macros/kunit.rs                          |  2 +-
 rust/uapi/lib.rs                              |  5 +-
 scripts/Makefile.build                        |  6 +-
 scripts/min-tool-version.sh                   |  4 +-
 scripts/rust_is_available.sh                  | 36 +-----------
 scripts/rust_is_available_bindgen_0_66.h      |  2 -
 ...ust_is_available_bindgen_libclang_concat.h |  3 -
 scripts/rust_is_available_test.py             | 58 +------------------
 37 files changed, 79 insertions(+), 446 deletions(-)
 delete mode 100644 drivers/android/binder/page_range_helper.c
 delete mode 100644 drivers/android/binder/page_range_helper.h
 delete mode 100644 rust/kernel/slice.rs
 delete mode 100644 scripts/rust_is_available_bindgen_0_66.h
 delete mode 100644 scripts/rust_is_available_bindgen_libclang_concat.h

--
2.53.0

[PATCH 01/33] rust: bump Rust minimum supported version to 1.85.0 (Debian Trixie)

[Miguel Ojeda]

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's release happened on 2025-08-09 [4], 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 version.

Then, in later commits, clean up most of the workarounds and other bits
that this upgrade of the minimum allows us.

pin-init was left as-is since the patches come from upstream. And the
vendored crates are unmodified, since we do not want to change those.

Note that the minimum LLVM major version for Rust 1.85.0 is LLVM 18 (the
Rust upstream binaries use LLVM 19.1.7), thus e.g. `RUSTC_LLVM_VERSION`
tests can also be updated, but there are no suitable ones to simplify.

Ubuntu 25.10 also has a recent enough Rust toolchain [5], and they also
provide versioned packages with a Rust 1.85.1 toolchain even back to
Ubuntu 22.04 LTS [6].

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://www.debian.org/releases/trixie/ [4]
Link: https://packages.ubuntu.com/search?suite=all&searchon=names&keywords=rustc [5]
Link: https://launchpad.net/ubuntu/+source/rustc-1.85 [6]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 Documentation/process/changes.rst | 2 +-
 scripts/min-tool-version.sh       | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst
index 6b373e193548..474594bd4831 100644
--- a/Documentation/process/changes.rst
+++ b/Documentation/process/changes.rst
@@ -31,7 +31,7 @@ you probably needn't concern yourself with pcmciautils.
 ====================== ===============  ========================================
 GNU C                  8.1              gcc --version
 Clang/LLVM (optional)  15.0.0           clang --version
-Rust (optional)        1.78.0           rustc --version
+Rust (optional)        1.85.0           rustc --version
 bindgen (optional)     0.65.1           bindgen --version
 GNU make               4.0              make --version
 bash                   4.2              bash --version
diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh
index 99b5575c1ef7..a270ec761f64 100755
--- a/scripts/min-tool-version.sh
+++ b/scripts/min-tool-version.sh
@@ -31,7 +31,7 @@ llvm)
 	fi
 	;;
 rustc)
-	echo 1.78.0
+	echo 1.85.0
 	;;
 bindgen)
 	echo 0.65.1
-- 
2.53.0

[PATCH 02/33] rust: bump Clippy's MSRV and clean `incompatible_msrv` allows

[Miguel Ojeda]

Following the Rust compiler bump, we can now update Clippy's MSRV we
set in the configuration, which will improve the diagnostics it generates.

Thus do so and clean a few of the `allow`s that are not needed anymore.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 .clippy.toml                      | 2 +-
 drivers/gpu/nova-core/gsp/cmdq.rs | 6 +-----
 rust/kernel/ptr.rs                | 1 -
 rust/kernel/transmute.rs          | 2 --
 4 files changed, 2 insertions(+), 9 deletions(-)

diff --git a/.clippy.toml b/.clippy.toml
index a51de9a46380..b0a78cc8be20 100644
--- a/.clippy.toml
+++ b/.clippy.toml
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 
-msrv = "1.78.0"
+msrv = "1.85.0"
 
 check-private-items = true
 
diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs b/drivers/gpu/nova-core/gsp/cmdq.rs
index 46819a82a51a..d9f69366642a 100644
--- a/drivers/gpu/nova-core/gsp/cmdq.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq.rs
@@ -281,7 +281,6 @@ fn allocate_command(&mut self, size: usize) -> Result<GspCommand<'_>> {
         let (slice_1, slice_2) = {
             let (slice_1, slice_2) = self.driver_write_area();
 
-            #[allow(clippy::incompatible_msrv)]
             (slice_1.as_flattened_mut(), slice_2.as_flattened_mut())
         };
 
@@ -572,10 +571,7 @@ fn wait_for_msg(&self, timeout: Delta) -> Result<GspMessage<'_>> {
             Delta::from_millis(1),
             timeout,
         )
-        .map(|(slice_1, slice_2)| {
-            #[allow(clippy::incompatible_msrv)]
-            (slice_1.as_flattened(), slice_2.as_flattened())
-        })?;
+        .map(|(slice_1, slice_2)| (slice_1.as_flattened(), slice_2.as_flattened()))?;
 
         // Extract the `GspMsgElement`.
         let (header, slice_1) = GspMsgElement::from_bytes_prefix(slice_1).ok_or(EIO)?;
diff --git a/rust/kernel/ptr.rs b/rust/kernel/ptr.rs
index 512e2eabe3ad..bd669e74e1cc 100644
--- a/rust/kernel/ptr.rs
+++ b/rust/kernel/ptr.rs
@@ -81,7 +81,6 @@ pub const fn new_checked(align: usize) -> Option<Self> {
     /// This is equivalent to [`align_of`], but with the return value provided as an [`Alignment`].
     #[inline(always)]
     pub const fn of<T>() -> Self {
-        #![allow(clippy::incompatible_msrv)]
         // This cannot panic since alignments are always powers of two.
         //
         // We unfortunately cannot use `new` as it would require the `generic_const_exprs` feature.
diff --git a/rust/kernel/transmute.rs b/rust/kernel/transmute.rs
index 5711580c9f9b..b9e6eadc08f5 100644
--- a/rust/kernel/transmute.rs
+++ b/rust/kernel/transmute.rs
@@ -49,7 +49,6 @@ fn from_bytes(bytes: &[u8]) -> Option<&Self>
         let slice_ptr = bytes.as_ptr().cast::<Self>();
         let size = size_of::<Self>();
 
-        #[allow(clippy::incompatible_msrv)]
         if bytes.len() == size && slice_ptr.is_aligned() {
             // SAFETY: Size and alignment were just checked.
             unsafe { Some(&*slice_ptr) }
@@ -92,7 +91,6 @@ fn from_bytes_mut(bytes: &mut [u8]) -> Option<&mut Self>
         let slice_ptr = bytes.as_mut_ptr().cast::<Self>();
         let size = size_of::<Self>();
 
-        #[allow(clippy::incompatible_msrv)]
         if bytes.len() == size && slice_ptr.is_aligned() {
             // SAFETY: Size and alignment were just checked.
             unsafe { Some(&mut *slice_ptr) }
-- 
2.53.0

[PATCH 03/33] rust: simplify `RUSTC_VERSION` Kconfig conditions

[Miguel Ojeda]

With the Rust version bump in place, several Kconfig conditions based on
`RUSTC_VERSION` are always true.

Thus simplify them.

The minimum supported major LLVM version by our new Rust minimum version
is now LLVM 18, instead of LLVM 16. However, there are no possible
cleanups for `RUSTC_LLVM_VERSION`.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 arch/Kconfig       | 3 +--
 arch/arm64/Kconfig | 8 --------
 arch/riscv/Kconfig | 3 ---
 init/Kconfig       | 2 --
 4 files changed, 1 insertion(+), 15 deletions(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index 102ddbd4298e..84089e80584b 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -968,10 +968,9 @@ config HAVE_CFI_ICALL_NORMALIZE_INTEGERS
 config HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
 	def_bool y
 	depends on HAVE_CFI_ICALL_NORMALIZE_INTEGERS
-	depends on RUSTC_VERSION >= 107900
 	depends on ARM64 || X86_64
 	# With GCOV/KASAN we need this fix: https://github.com/rust-lang/rust/pull/129373
-	depends on (RUSTC_LLVM_VERSION >= 190103 && RUSTC_VERSION >= 108200) || \
+	depends on RUSTC_LLVM_VERSION >= 190103 || \
 		(!GCOV_KERNEL && !KASAN_GENERIC && !KASAN_SW_TAGS)
 
 config CFI_PERMISSIVE
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 38dba5f7e4d2..c91130c7fba1 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -291,14 +291,6 @@ config ARM64
 config RUSTC_SUPPORTS_ARM64
 	def_bool y
 	depends on CPU_LITTLE_ENDIAN
-	# Shadow call stack is only supported on certain rustc versions.
-	#
-	# When using the UNWIND_PATCH_PAC_INTO_SCS option, rustc version 1.80+ is
-	# required due to use of the -Zfixed-x18 flag.
-	#
-	# Otherwise, rustc version 1.82+ is required due to use of the
-	# -Zsanitizer=shadow-call-stack flag.
-	depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 || RUSTC_VERSION >= 108000 && UNWIND_PATCH_PAC_INTO_SCS
 
 config CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS
 	def_bool CC_IS_CLANG
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 90c531e6abf5..ddc534402400 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -232,9 +232,6 @@ config RISCV
 config RUSTC_SUPPORTS_RISCV
 	def_bool y
 	depends on 64BIT
-	# Shadow call stack requires rustc version 1.82+ due to use of the
-	# -Zsanitizer=shadow-call-stack flag.
-	depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200
 
 config CLANG_SUPPORTS_DYNAMIC_FTRACE
 	def_bool CC_IS_CLANG
diff --git a/init/Kconfig b/init/Kconfig
index 36d32ea44594..b8a1ab0d49d4 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -2193,9 +2193,7 @@ config RUST
 	depends on !DEBUG_INFO_BTF || (PAHOLE_HAS_LANG_EXCLUDE && !LTO)
 	depends on !CFI || HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
 	select CFI_ICALL_NORMALIZE_INTEGERS if CFI
-	depends on !CALL_PADDING || RUSTC_VERSION >= 108100
 	depends on !KASAN_SW_TAGS
-	depends on !(MITIGATION_RETHUNK && KASAN) || RUSTC_VERSION >= 108300
 	help
 	  Enables Rust support in the kernel.
 
-- 
2.53.0

[PATCH 04/33] rust: remove `RUSTC_HAS_SLICE_AS_FLATTENED` and simplify code

[Miguel Ojeda]

With the Rust version bump in place, the `RUSTC_HAS_SLICE_AS_FLATTENED`
Kconfig (automatic) option is always true.

Thus remove the option and simplify the code.

In particular, this includes removing the `slice` module which contained
the temporary slice helpers, i.e. the `AsFlattened` extension trait and
its `impl`s.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 init/Kconfig           |  3 ---
 rust/kernel/lib.rs     |  1 -
 rust/kernel/prelude.rs |  3 ---
 rust/kernel/slice.rs   | 49 ------------------------------------------
 4 files changed, 56 deletions(-)
 delete mode 100644 rust/kernel/slice.rs

diff --git a/init/Kconfig b/init/Kconfig
index b8a1ab0d49d4..c38f49228157 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -178,9 +178,6 @@ config LD_CAN_USE_KEEP_IN_OVERLAY
 	# https://github.com/llvm/llvm-project/pull/130661
 	def_bool LD_IS_BFD || LLD_VERSION >= 210000
 
-config RUSTC_HAS_SLICE_AS_FLATTENED
-	def_bool RUSTC_VERSION >= 108000
-
 config RUSTC_HAS_COERCE_POINTEE
 	def_bool RUSTC_VERSION >= 108400
 
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 138d846f798d..621cae75030c 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -140,7 +140,6 @@
 pub mod security;
 pub mod seq_file;
 pub mod sizes;
-pub mod slice;
 #[cfg(CONFIG_SOC_BUS)]
 pub mod soc;
 #[doc(hidden)]
diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs
index 6a54597fa0a2..1cf051b83394 100644
--- a/rust/kernel/prelude.rs
+++ b/rust/kernel/prelude.rs
@@ -53,6 +53,3 @@
 pub use super::current;
 
 pub use super::uaccess::UserPtr;
-
-#[cfg(not(CONFIG_RUSTC_HAS_SLICE_AS_FLATTENED))]
-pub use super::slice::AsFlattened;
diff --git a/rust/kernel/slice.rs b/rust/kernel/slice.rs
deleted file mode 100644
index ca2cde135061..000000000000
--- a/rust/kernel/slice.rs
+++ /dev/null
@@ -1,49 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-
-//! Additional (and temporary) slice helpers.
-
-/// Extension trait providing a portable version of [`as_flattened`] and
-/// [`as_flattened_mut`].
-///
-/// In Rust 1.80, the previously unstable `slice::flatten` family of methods
-/// have been stabilized and renamed from `flatten` to `as_flattened`.
-///
-/// This creates an issue for as long as the MSRV is < 1.80, as the same functionality is provided
-/// by different methods depending on the compiler version.
-///
-/// This extension trait solves this by abstracting `as_flatten` and calling the correct method
-/// depending on the Rust version.
-///
-/// This trait can be removed once the MSRV passes 1.80.
-///
-/// [`as_flattened`]: https://doc.rust-lang.org/std/primitive.slice.html#method.as_flattened
-/// [`as_flattened_mut`]: https://doc.rust-lang.org/std/primitive.slice.html#method.as_flattened_mut
-#[cfg(not(CONFIG_RUSTC_HAS_SLICE_AS_FLATTENED))]
-pub trait AsFlattened<T> {
-    /// Takes a `&[[T; N]]` and flattens it to a `&[T]`.
-    ///
-    /// This is an portable layer on top of [`as_flattened`]; see its documentation for details.
-    ///
-    /// [`as_flattened`]: https://doc.rust-lang.org/std/primitive.slice.html#method.as_flattened
-    fn as_flattened(&self) -> &[T];
-
-    /// Takes a `&mut [[T; N]]` and flattens it to a `&mut [T]`.
-    ///
-    /// This is an portable layer on top of [`as_flattened_mut`]; see its documentation for details.
-    ///
-    /// [`as_flattened_mut`]: https://doc.rust-lang.org/std/primitive.slice.html#method.as_flattened_mut
-    fn as_flattened_mut(&mut self) -> &mut [T];
-}
-
-#[cfg(not(CONFIG_RUSTC_HAS_SLICE_AS_FLATTENED))]
-impl<T, const N: usize> AsFlattened<T> for [[T; N]] {
-    #[allow(clippy::incompatible_msrv)]
-    fn as_flattened(&self) -> &[T] {
-        self.flatten()
-    }
-
-    #[allow(clippy::incompatible_msrv)]
-    fn as_flattened_mut(&mut self) -> &mut [T] {
-        self.flatten_mut()
-    }
-}
-- 
2.53.0

[PATCH 05/33] rust: remove `RUSTC_HAS_COERCE_POINTEE` and simplify code

[Miguel Ojeda]

With the Rust version bump in place, the `RUSTC_HAS_COERCE_POINTEE`
Kconfig (automatic) option is always true.

Thus remove the option and simplify the code.

In particular, this includes removing our use of the predecessor unstable
features we used with Rust < 1.84.0 (`coerce_unsized`, `dispatch_from_dyn`
and `unsize`).

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 init/Kconfig              |  3 ---
 rust/kernel/alloc/kbox.rs | 29 ++---------------------------
 rust/kernel/lib.rs        |  8 +-------
 rust/kernel/list/arc.rs   | 22 +---------------------
 rust/kernel/sync/arc.rs   | 21 ++-------------------
 5 files changed, 6 insertions(+), 77 deletions(-)

diff --git a/init/Kconfig b/init/Kconfig
index c38f49228157..f9fac458e4d4 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -178,9 +178,6 @@ config LD_CAN_USE_KEEP_IN_OVERLAY
 	# https://github.com/llvm/llvm-project/pull/130661
 	def_bool LD_IS_BFD || LLD_VERSION >= 210000
 
-config RUSTC_HAS_COERCE_POINTEE
-	def_bool RUSTC_VERSION >= 108400
-
 config RUSTC_HAS_SPAN_FILE
 	def_bool RUSTC_VERSION >= 108800
 
diff --git a/rust/kernel/alloc/kbox.rs b/rust/kernel/alloc/kbox.rs
index 622b3529edfc..bd6da02c7ab8 100644
--- a/rust/kernel/alloc/kbox.rs
+++ b/rust/kernel/alloc/kbox.rs
@@ -77,33 +77,8 @@
 /// `self.0` is always properly aligned and either points to memory allocated with `A` or, for
 /// zero-sized types, is a dangling, well aligned pointer.
 #[repr(transparent)]
-#[cfg_attr(CONFIG_RUSTC_HAS_COERCE_POINTEE, derive(core::marker::CoercePointee))]
-pub struct Box<#[cfg_attr(CONFIG_RUSTC_HAS_COERCE_POINTEE, pointee)] T: ?Sized, A: Allocator>(
-    NonNull<T>,
-    PhantomData<A>,
-);
-
-// This is to allow coercion from `Box<T, A>` to `Box<U, A>` if `T` can be converted to the
-// dynamically-sized type (DST) `U`.
-#[cfg(not(CONFIG_RUSTC_HAS_COERCE_POINTEE))]
-impl<T, U, A> core::ops::CoerceUnsized<Box<U, A>> for Box<T, A>
-where
-    T: ?Sized + core::marker::Unsize<U>,
-    U: ?Sized,
-    A: Allocator,
-{
-}
-
-// This is to allow `Box<U, A>` to be dispatched on when `Box<T, A>` can be coerced into `Box<U,
-// A>`.
-#[cfg(not(CONFIG_RUSTC_HAS_COERCE_POINTEE))]
-impl<T, U, A> core::ops::DispatchFromDyn<Box<U, A>> for Box<T, A>
-where
-    T: ?Sized + core::marker::Unsize<U>,
-    U: ?Sized,
-    A: Allocator,
-{
-}
+#[derive(core::marker::CoercePointee)]
+pub struct Box<#[pointee] T: ?Sized, A: Allocator>(NonNull<T>, PhantomData<A>);
 
 /// Type alias for [`Box`] with a [`Kmalloc`] allocator.
 ///
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 621cae75030c..66a09d77a2c4 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -39,17 +39,11 @@
 //
 // Expected to become stable.
 #![feature(arbitrary_self_types)]
+#![feature(derive_coerce_pointee)]
 //
 // To be determined.
 #![feature(used_with_arg)]
 //
-// `feature(derive_coerce_pointee)` is expected to become stable. Before Rust
-// 1.84.0, it did not exist, so enable the predecessor features.
-#![cfg_attr(CONFIG_RUSTC_HAS_COERCE_POINTEE, feature(derive_coerce_pointee))]
-#![cfg_attr(not(CONFIG_RUSTC_HAS_COERCE_POINTEE), feature(coerce_unsized))]
-#![cfg_attr(not(CONFIG_RUSTC_HAS_COERCE_POINTEE), feature(dispatch_from_dyn))]
-#![cfg_attr(not(CONFIG_RUSTC_HAS_COERCE_POINTEE), feature(unsize))]
-//
 // `feature(file_with_nul)` is expected to become stable. Before Rust 1.89.0, it did not exist, so
 // enable it conditionally.
 #![cfg_attr(CONFIG_RUSTC_HAS_FILE_WITH_NUL, feature(file_with_nul))]
diff --git a/rust/kernel/list/arc.rs b/rust/kernel/list/arc.rs
index e1082423909c..a9a2b0178f65 100644
--- a/rust/kernel/list/arc.rs
+++ b/rust/kernel/list/arc.rs
@@ -160,7 +160,7 @@ fn try_new_list_arc(&self) -> bool {
 ///
 /// [`List`]: crate::list::List
 #[repr(transparent)]
-#[cfg_attr(CONFIG_RUSTC_HAS_COERCE_POINTEE, derive(core::marker::CoercePointee))]
+#[derive(core::marker::CoercePointee)]
 pub struct ListArc<T, const ID: u64 = 0>
 where
     T: ListArcSafe<ID> + ?Sized,
@@ -443,26 +443,6 @@ fn as_ref(&self) -> &Arc<T> {
     }
 }
 
-// This is to allow coercion from `ListArc<T>` to `ListArc<U>` if `T` can be converted to the
-// dynamically-sized type (DST) `U`.
-#[cfg(not(CONFIG_RUSTC_HAS_COERCE_POINTEE))]
-impl<T, U, const ID: u64> core::ops::CoerceUnsized<ListArc<U, ID>> for ListArc<T, ID>
-where
-    T: ListArcSafe<ID> + core::marker::Unsize<U> + ?Sized,
-    U: ListArcSafe<ID> + ?Sized,
-{
-}
-
-// This is to allow `ListArc<U>` to be dispatched on when `ListArc<T>` can be coerced into
-// `ListArc<U>`.
-#[cfg(not(CONFIG_RUSTC_HAS_COERCE_POINTEE))]
-impl<T, U, const ID: u64> core::ops::DispatchFromDyn<ListArc<U, ID>> for ListArc<T, ID>
-where
-    T: ListArcSafe<ID> + core::marker::Unsize<U> + ?Sized,
-    U: ListArcSafe<ID> + ?Sized,
-{
-}
-
 /// A utility for tracking whether a [`ListArc`] exists using an atomic.
 ///
 /// # Invariants
diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index 921e19333b89..18d6c0d62ce0 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -128,7 +128,7 @@
 /// # Ok::<(), Error>(())
 /// ```
 #[repr(transparent)]
-#[cfg_attr(CONFIG_RUSTC_HAS_COERCE_POINTEE, derive(core::marker::CoercePointee))]
+#[derive(core::marker::CoercePointee)]
 pub struct Arc<T: ?Sized> {
     ptr: NonNull<ArcInner<T>>,
     // NB: this informs dropck that objects of type `ArcInner<T>` may be used in `<Arc<T> as
@@ -182,15 +182,6 @@ unsafe fn container_of(ptr: *const T) -> NonNull<ArcInner<T>> {
     }
 }
 
-// This is to allow coercion from `Arc<T>` to `Arc<U>` if `T` can be converted to the
-// dynamically-sized type (DST) `U`.
-#[cfg(not(CONFIG_RUSTC_HAS_COERCE_POINTEE))]
-impl<T: ?Sized + core::marker::Unsize<U>, U: ?Sized> core::ops::CoerceUnsized<Arc<U>> for Arc<T> {}
-
-// This is to allow `Arc<U>` to be dispatched on when `Arc<T>` can be coerced into `Arc<U>`.
-#[cfg(not(CONFIG_RUSTC_HAS_COERCE_POINTEE))]
-impl<T: ?Sized + core::marker::Unsize<U>, U: ?Sized> core::ops::DispatchFromDyn<Arc<U>> for Arc<T> {}
-
 // SAFETY: It is safe to send `Arc<T>` to another thread when the underlying `T` is `Sync` because
 // it effectively means sharing `&T` (which is safe because `T` is `Sync`); additionally, it needs
 // `T` to be `Send` because any thread that has an `Arc<T>` may ultimately access `T` using a
@@ -547,20 +538,12 @@ fn from(item: Pin<UniqueArc<T>>) -> Self {
 /// # Ok::<(), Error>(())
 /// ```
 #[repr(transparent)]
-#[cfg_attr(CONFIG_RUSTC_HAS_COERCE_POINTEE, derive(core::marker::CoercePointee))]
+#[derive(core::marker::CoercePointee)]
 pub struct ArcBorrow<'a, T: ?Sized + 'a> {
     inner: NonNull<ArcInner<T>>,
     _p: PhantomData<&'a ()>,
 }
 
-// This is to allow `ArcBorrow<U>` to be dispatched on when `ArcBorrow<T>` can be coerced into
-// `ArcBorrow<U>`.
-#[cfg(not(CONFIG_RUSTC_HAS_COERCE_POINTEE))]
-impl<T: ?Sized + core::marker::Unsize<U>, U: ?Sized> core::ops::DispatchFromDyn<ArcBorrow<'_, U>>
-    for ArcBorrow<'_, T>
-{
-}
-
 impl<T: ?Sized> Clone for ArcBorrow<'_, T> {
     fn clone(&self) -> Self {
         *self
-- 
2.53.0

[PATCH 06/33] rust: kbuild: remove skipping of `-Wrustdoc::unescaped_backticks`

[Miguel Ojeda]

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]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/Makefile | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/rust/Makefile b/rust/Makefile
index 5eca6a817966..212759b5eb7d 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -75,8 +75,7 @@ core-edition := $(if $(call rustc-min-version,108700),2024,2021)
 
 core-skip_flags := \
     --edition=2021 \
-    -Wunreachable_pub \
-    -Wrustdoc::unescaped_backticks
+    -Wunreachable_pub
 
 core-flags := \
     --edition=$(core-edition) \
@@ -213,8 +212,6 @@ rustdoc-macros: $(src)/macros/lib.rs rustdoc-clean rustdoc-proc_macro2 \
     rustdoc-quote rustdoc-syn FORCE
 	+$(call if_changed,rustdoc)
 
-# Starting with Rust 1.82.0, skipping `-Wrustdoc::unescaped_backticks` should
-# not be needed -- see https://github.com/rust-lang/rust/pull/128307.
 rustdoc-core: private skip_flags = $(core-skip_flags)
 rustdoc-core: private rustc_target_flags = $(core-flags)
 rustdoc-core: $(RUST_LIB_SRC)/core/src/lib.rs rustdoc-clean FORCE
-- 
2.53.0

[PATCH 07/33] rust: kbuild: remove `feature(...)`s that are now stable

[Miguel Ojeda]

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.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/Makefile          |  2 --
 rust/kernel/lib.rs     | 21 ---------------------
 scripts/Makefile.build |  6 +-----
 3 files changed, 1 insertion(+), 28 deletions(-)

diff --git a/rust/Makefile b/rust/Makefile
index 212759b5eb7d..193cf06eea64 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -86,10 +86,8 @@ proc_macro2-cfgs := \
     wrap_proc_macro \
     $(if $(call rustc-min-version,108800),proc_macro_span_file proc_macro_span_location)
 
-# Stable since Rust 1.79.0: `feature(proc_macro_byte_character,proc_macro_c_str_literals)`.
 proc_macro2-flags := \
     --cap-lints=allow \
-    -Zcrate-attr='feature(proc_macro_byte_character,proc_macro_c_str_literals)' \
     $(call cfgs-to-flags,$(proc_macro2-cfgs))
 
 quote-cfgs := \
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 66a09d77a2c4..b48221a5b4ec 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -16,27 +16,6 @@
 // Please see https://github.com/Rust-for-Linux/linux/issues/2 for details on
 // the unstable features in use.
 //
-// Stable since Rust 1.79.0.
-#![feature(generic_nonzero)]
-#![feature(inline_const)]
-#![feature(pointer_is_aligned)]
-//
-// Stable since Rust 1.80.0.
-#![feature(slice_flatten)]
-//
-// Stable since Rust 1.81.0.
-#![feature(lint_reasons)]
-//
-// Stable since Rust 1.82.0.
-#![feature(raw_ref_op)]
-//
-// Stable since Rust 1.83.0.
-#![feature(const_maybe_uninit_as_mut_ptr)]
-#![feature(const_mut_refs)]
-#![feature(const_option)]
-#![feature(const_ptr_write)]
-#![feature(const_refs_to_cell)]
-//
 // Expected to become stable.
 #![feature(arbitrary_self_types)]
 #![feature(derive_coerce_pointee)]
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index a6d1a2b210aa..d71193a45e1c 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -310,17 +310,13 @@ $(obj)/%.lst: $(obj)/%.c FORCE
 
 # The features in this list are the ones allowed for non-`rust/` code.
 #
-#   - Stable since Rust 1.79.0: `feature(inline_const)`.
-#   - Stable since Rust 1.81.0: `feature(lint_reasons)`.
-#   - Stable since Rust 1.82.0: `feature(asm_const)`,
-#     `feature(offset_of_nested)`, `feature(raw_ref_op)`.
 #   - Stable since Rust 1.87.0: `feature(asm_goto)`.
 #   - Expected to become stable: `feature(arbitrary_self_types)`.
 #   - To be determined: `feature(used_with_arg)`.
 #
 # Please see https://github.com/Rust-for-Linux/linux/issues/2 for details on
 # the unstable features in use.
-rust_allowed_features := asm_const,asm_goto,arbitrary_self_types,inline_const,lint_reasons,offset_of_nested,raw_ref_op,used_with_arg
+rust_allowed_features := arbitrary_self_types,asm_goto,used_with_arg
 
 # `--out-dir` is required to avoid temporaries being created by `rustc` in the
 # current working directory, which may be not accessible in the out-of-tree
-- 
2.53.0

[PATCH 08/33] rust: kbuild: simplify `--remap-path-prefix` workaround

[Miguel Ojeda]

With the minimum version bump in place, `rustdoc` now always recognizes
the `--remap-path-prefix` flag.

In addition, the Internal Compiler Error that the comment mentions [1]
was fixed in Rust 1.87.0 [2], so we still need to skip the flag for
the normal `rustdoc` case, but not for `--test` since the ICE does not
reproduce there -- please see commit 2c8725c1dca3 ("rust: kbuild: skip
`--remap-path-prefix` for `rustdoc`").

Thus update the comment and remove the skipping of the flag for the
`--test` case.

Note that commit dda135077ecc ("rust: build: remap path to avoid
absolute path") re-landed the `--remap-path-prefix` flag (together with
`--remap-path-scope`), so we keep the workaround, i.e. an alternative
could have been to simply delete the skip entirely, but since we still
have it and it will be needed when this gets merged, let's keep it.

Link: https://github.com/rust-lang/rust/issues/138520 [1]
Link: https://github.com/rust-lang/rust/pull/138556 [2]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/Makefile | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/rust/Makefile b/rust/Makefile
index 193cf06eea64..708530ee3613 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -142,10 +142,9 @@ rustdoc_modifiers_workaround := $(if $(call rustc-min-version,108800),-Cunsafe-a
 # Similarly, for doctests (https://github.com/rust-lang/rust/issues/146465).
 doctests_modifiers_workaround := $(rustdoc_modifiers_workaround)$(if $(call rustc-min-version,109100),$(comma)sanitizer)
 
-# `rustc` recognizes `--remap-path-prefix` since 1.26.0, but `rustdoc` only
-# since Rust 1.81.0. Moreover, `rustdoc` ICEs on out-of-tree builds since Rust
-# 1.82.0 (https://github.com/rust-lang/rust/issues/138520). Thus workaround both
-# issues skipping the flag. The former also applies to `RUSTDOC TK`.
+# `rustdoc` ICEs on out-of-tree builds in Rust < 1.87.0
+# (https://github.com/rust-lang/rust/issues/138520). Thus workaround the
+# issue skipping the flag.
 quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $<
       cmd_rustdoc = \
 	OBJTREE=$(abspath $(objtree)) \
@@ -333,7 +332,7 @@ quiet_cmd_rustdoc_test_kernel = RUSTDOC TK $<
 	rm -rf $(objtree)/$(obj)/test/doctests/kernel; \
 	mkdir -p $(objtree)/$(obj)/test/doctests/kernel; \
 	OBJTREE=$(abspath $(objtree)) \
-	$(RUSTDOC) --test $(filter-out --remap-path-prefix=%,$(rust_flags)) \
+	$(RUSTDOC) --test $(rust_flags) \
 		-L$(objtree)/$(obj) --extern ffi --extern pin_init \
 		--extern kernel --extern build_error --extern macros \
 		--extern bindings --extern uapi \
-- 
2.53.0

[PATCH 09/33] rust: kbuild: make `--remap-path-prefix` workaround conditional

[Miguel Ojeda]

The Internal Compiler Error that the comment mentions [1] was fixed in
Rust 1.87.0 [2]. And, for other workarounds, we plan on limiting where
we apply them [3].

Thus limit the ICE one too.

This will help to make sure the workaround is not needed anymore on
newer versions.

Link: https://github.com/rust-lang/rust/issues/138520 [1]
Link: https://github.com/rust-lang/rust/pull/138556 [2]
Link: https://lore.kernel.org/rust-for-linux/20260205131815.2943152-2-mlksvender@gmail.com/ [3]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/Makefile | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/rust/Makefile b/rust/Makefile
index 708530ee3613..163d2258e93f 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -145,10 +145,12 @@ doctests_modifiers_workaround := $(rustdoc_modifiers_workaround)$(if $(call rust
 # `rustdoc` ICEs on out-of-tree builds in Rust < 1.87.0
 # (https://github.com/rust-lang/rust/issues/138520). Thus workaround the
 # issue skipping the flag.
+rustdoc_remap_workaround := $(if $(call rustc-min-version,108700),,--remap-path-prefix=%)
+
 quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $<
       cmd_rustdoc = \
 	OBJTREE=$(abspath $(objtree)) \
-	$(RUSTDOC) $(filter-out $(skip_flags) --remap-path-prefix=%,$(if $(rustdoc_host),$(rust_common_flags),$(rust_flags))) \
+	$(RUSTDOC) $(filter-out $(skip_flags) $(rustdoc_remap_workaround),$(if $(rustdoc_host),$(rust_common_flags),$(rust_flags))) \
 		$(rustc_target_flags) -L$(objtree)/$(obj) \
 		-Zunstable-options --generate-link-to-definition \
 		--output $(rustdoc_output) \
-- 
2.53.0

[PATCH 10/33] rust: transmute: simplify code with Rust 1.80.0 `split_at_*checked()`

[Miguel Ojeda]

`feature(split_at_checked)` [1] has been stabilized in Rust 1.80.0 [2],
which is beyond our new minimum Rust version (Rust 1.85.0).

Thus simplify the code using `split_at_*checked()`.

Link: https://github.com/rust-lang/rust/issues/119128 [1]
Link: https://github.com/rust-lang/rust/pull/124678 [2]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/transmute.rs | 33 ++++++---------------------------
 1 file changed, 6 insertions(+), 27 deletions(-)

diff --git a/rust/kernel/transmute.rs b/rust/kernel/transmute.rs
index b9e6eadc08f5..654b5ede2fe2 100644
--- a/rust/kernel/transmute.rs
+++ b/rust/kernel/transmute.rs
@@ -66,16 +66,9 @@ fn from_bytes_prefix(bytes: &[u8]) -> Option<(&Self, &[u8])>
     where
         Self: Sized,
     {
-        if bytes.len() < size_of::<Self>() {
-            None
-        } else {
-            // PANIC: We checked that `bytes.len() >= size_of::<Self>`, thus `split_at` cannot
-            // panic.
-            // TODO: replace with `split_at_checked` once the MSRV is >= 1.80.
-            let (prefix, remainder) = bytes.split_at(size_of::<Self>());
+        let (prefix, remainder) = bytes.split_at_checked(size_of::<Self>())?;
 
-            Self::from_bytes(prefix).map(|s| (s, remainder))
-        }
+        Self::from_bytes(prefix).map(|s| (s, remainder))
     }
 
     /// Converts a mutable slice of bytes to a reference to `Self`.
@@ -108,16 +101,9 @@ fn from_bytes_mut_prefix(bytes: &mut [u8]) -> Option<(&mut Self, &mut [u8])>
     where
         Self: AsBytes + Sized,
     {
-        if bytes.len() < size_of::<Self>() {
-            None
-        } else {
-            // PANIC: We checked that `bytes.len() >= size_of::<Self>`, thus `split_at_mut` cannot
-            // panic.
-            // TODO: replace with `split_at_mut_checked` once the MSRV is >= 1.80.
-            let (prefix, remainder) = bytes.split_at_mut(size_of::<Self>());
+        let (prefix, remainder) = bytes.split_at_mut_checked(size_of::<Self>())?;
 
-            Self::from_bytes_mut(prefix).map(|s| (s, remainder))
-        }
+        Self::from_bytes_mut(prefix).map(|s| (s, remainder))
     }
 
     /// Creates an owned instance of `Self` by copying `bytes`.
@@ -147,16 +133,9 @@ fn from_bytes_copy_prefix(bytes: &[u8]) -> Option<(Self, &[u8])>
     where
         Self: Sized,
     {
-        if bytes.len() < size_of::<Self>() {
-            None
-        } else {
-            // PANIC: We checked that `bytes.len() >= size_of::<Self>`, thus `split_at` cannot
-            // panic.
-            // TODO: replace with `split_at_checked` once the MSRV is >= 1.80.
-            let (prefix, remainder) = bytes.split_at(size_of::<Self>());
+        let (prefix, remainder) = bytes.split_at_checked(size_of::<Self>())?;
 
-            Self::from_bytes_copy(prefix).map(|s| (s, remainder))
-        }
+        Self::from_bytes_copy(prefix).map(|s| (s, remainder))
     }
 }
 
-- 
2.53.0

[PATCH 11/33] rust: alloc: simplify with `NonNull::add()` now that it is stable

[Miguel Ojeda]

Currently we need to go through raw pointers and then re-create the
`NonNull` from the result of offsetting the raw pointer.

Thus, now that we bump the Rust minimum version, simplify using
`NonNull::add()` and clean the TODO note.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/alloc/allocator/iter.rs | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/rust/kernel/alloc/allocator/iter.rs b/rust/kernel/alloc/allocator/iter.rs
index 5759f86029b7..e0a70b7a744a 100644
--- a/rust/kernel/alloc/allocator/iter.rs
+++ b/rust/kernel/alloc/allocator/iter.rs
@@ -42,15 +42,9 @@ fn next(&mut self) -> Option<Self::Item> {
             return None;
         }
 
-        // TODO: Use `NonNull::add()` instead, once the minimum supported compiler version is
-        // bumped to 1.80 or later.
-        //
         // SAFETY: `offset` is in the interval `[0, (self.page_count() - 1) * page::PAGE_SIZE]`,
         // hence the resulting pointer is guaranteed to be within the same allocation.
-        let ptr = unsafe { self.buf.as_ptr().add(offset) };
-
-        // SAFETY: `ptr` is guaranteed to be non-null given that it is derived from `self.buf`.
-        let ptr = unsafe { NonNull::new_unchecked(ptr) };
+        let ptr = unsafe { self.buf.add(offset) };
 
         // SAFETY:
         // - `ptr` is a valid pointer to a `Vmalloc` allocation.
-- 
2.53.0

[PATCH 12/33] rust: macros: update `extract_if` MSRV TODO comment

[Miguel Ojeda]

`feature(extract_if)` was stabilized in Rust 1.87.0 [1].

Thus update the comment to reflect that.

Alternatively, we could use it unstably already.

Link: https://github.com/rust-lang/rust/pull/137109 [1]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/macros/kunit.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rust/macros/kunit.rs b/rust/macros/kunit.rs
index 6be880d634e2..6f6d746b8dbb 100644
--- a/rust/macros/kunit.rs
+++ b/rust/macros/kunit.rs
@@ -87,7 +87,7 @@ pub(crate) fn kunit_tests(test_suite: Ident, mut module: ItemMod) -> Result<Toke
             continue;
         };
 
-        // TODO: Replace below with `extract_if` when MSRV is bumped above 1.85.
+        // TODO: Replace with `extract_if` when MSRV is >= 1.87.0.
         let before_len = f.attrs.len();
         f.attrs.retain(|attr| !attr.path().is_ident("test"));
         if f.attrs.len() == before_len {
-- 
2.53.0

[PATCH 13/33] rust: block: update `const_refs_to_static` MSRV TODO comment

[Miguel Ojeda]

`feature(const_refs_to_static)` was stabilized in Rust 1.83.0 [1].

Thus update the comment to reflect that.

Link: https://github.com/rust-lang/rust/pull/129759 [1]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/kernel/block/mq/gen_disk.rs | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/rust/kernel/block/mq/gen_disk.rs b/rust/kernel/block/mq/gen_disk.rs
index c8b0ecb17082..912cb805caf5 100644
--- a/rust/kernel/block/mq/gen_disk.rs
+++ b/rust/kernel/block/mq/gen_disk.rs
@@ -140,9 +140,7 @@ pub fn build<T: Operations>(
             devnode: None,
             alternative_gpt_sector: None,
             get_unique_id: None,
-            // TODO: Set to THIS_MODULE. Waiting for const_refs_to_static feature to
-            // be merged (unstable in rustc 1.78 which is staged for linux 6.10)
-            // <https://github.com/rust-lang/rust/issues/119618>
+            // TODO: Set to `THIS_MODULE`.
             owner: core::ptr::null_mut(),
             pr_ops: core::ptr::null_mut(),
             free_disk: None,
-- 
2.53.0

[PATCH 14/33] rust: bump `bindgen` minimum supported version to 0.71.1 (Debian Trixie)

[Miguel Ojeda]

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

Debian Trixie was released with `bindgen` 0.71.1, which it still uses
to this day [2].

Debian Trixie's release happened on 2025-08-09 [3], 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 version.

Then, in later commits, clean up most of the workarounds and other bits
that this upgrade of the minimum allows us.

Ubuntu 25.10 also has a recent enough `bindgen` [4] (even the already
unsupported Ubuntu 25.04 had it), and they also provide versioned packages
with `bindgen` 0.71.1 back to Ubuntu 24.04 LTS [5].

Link: https://lwn.net/Articles/1050174/ [1]
Link: https://packages.debian.org/trixie/bindgen [2]
Link: https://www.debian.org/releases/trixie/ [3]
Link: https://packages.ubuntu.com/search?suite=all&searchon=names&keywords=bindgen [4]
Link: https://launchpad.net/ubuntu/+source/rust-bindgen-0.71 [5]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 Documentation/process/changes.rst | 2 +-
 scripts/min-tool-version.sh       | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst
index 474594bd4831..84156d031365 100644
--- a/Documentation/process/changes.rst
+++ b/Documentation/process/changes.rst
@@ -32,7 +32,7 @@ you probably needn't concern yourself with pcmciautils.
 GNU C                  8.1              gcc --version
 Clang/LLVM (optional)  15.0.0           clang --version
 Rust (optional)        1.85.0           rustc --version
-bindgen (optional)     0.65.1           bindgen --version
+bindgen (optional)     0.71.1           bindgen --version
 GNU make               4.0              make --version
 bash                   4.2              bash --version
 binutils               2.30             ld -v
diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh
index a270ec761f64..b96ec2d379b6 100755
--- a/scripts/min-tool-version.sh
+++ b/scripts/min-tool-version.sh
@@ -34,7 +34,7 @@ rustc)
 	echo 1.85.0
 	;;
 bindgen)
-	echo 0.65.1
+	echo 0.71.1
 	;;
 *)
 	echo "$1: unknown tool" >&2
-- 
2.53.0

[PATCH 15/33] rust: rust_is_available: remove warning for 0.66.[01] buggy versions

[Miguel Ojeda]

It is not possible anymore to fall into the issue that this warning was
alerting about given the `bindgen` version bump.

Thus simplify by removing the machinery behind it, including tests.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 scripts/rust_is_available.sh             | 13 ------------
 scripts/rust_is_available_bindgen_0_66.h |  2 --
 scripts/rust_is_available_test.py        | 26 +++---------------------
 3 files changed, 3 insertions(+), 38 deletions(-)
 delete mode 100644 scripts/rust_is_available_bindgen_0_66.h

diff --git a/scripts/rust_is_available.sh b/scripts/rust_is_available.sh
index d2323de0692c..77896e31dab5 100755
--- a/scripts/rust_is_available.sh
+++ b/scripts/rust_is_available.sh
@@ -163,19 +163,6 @@ if [ "$rust_bindings_generator_cversion" -lt "$rust_bindings_generator_min_cvers
 	echo >&2 "***"
 	exit 1
 fi
-if [ "$rust_bindings_generator_cversion" -eq 6600 ] ||
-	[ "$rust_bindings_generator_cversion" -eq 6601 ]; then
-	# Distributions may have patched the issue (e.g. Debian did).
-	if ! "$BINDGEN" $(dirname $0)/rust_is_available_bindgen_0_66.h >/dev/null; then
-		echo >&2 "***"
-		echo >&2 "*** Rust bindings generator '$BINDGEN' versions 0.66.0 and 0.66.1 may not"
-		echo >&2 "*** work due to a bug (https://github.com/rust-lang/rust-bindgen/pull/2567),"
-		echo >&2 "*** unless patched (like Debian's)."
-		echo >&2 "***   Your version:     $rust_bindings_generator_version"
-		echo >&2 "***"
-		warning=1
-	fi
-fi
 
 # Check that the `libclang` used by the Rust bindings generator is suitable.
 #
diff --git a/scripts/rust_is_available_bindgen_0_66.h b/scripts/rust_is_available_bindgen_0_66.h
deleted file mode 100644
index c0431293421c..000000000000
--- a/scripts/rust_is_available_bindgen_0_66.h
+++ /dev/null
@@ -1,2 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#define A "\0"
diff --git a/scripts/rust_is_available_test.py b/scripts/rust_is_available_test.py
index 4fcc319dea84..b66fa5933844 100755
--- a/scripts/rust_is_available_test.py
+++ b/scripts/rust_is_available_test.py
@@ -54,17 +54,12 @@ else:
 """)
 
     @classmethod
-    def generate_bindgen(cls, version_stdout, libclang_stderr, version_0_66_patched=False, libclang_concat_patched=False):
+    def generate_bindgen(cls, version_stdout, libclang_stderr, libclang_concat_patched=False):
         if libclang_stderr is None:
             libclang_case = f"raise SystemExit({cls.bindgen_default_bindgen_libclang_failure_exit_code})"
         else:
             libclang_case = f"print({repr(libclang_stderr)}, file=sys.stderr)"
 
-        if version_0_66_patched:
-            version_0_66_case = "pass"
-        else:
-            version_0_66_case = "raise SystemExit(1)"
-
         if libclang_concat_patched:
             libclang_concat_case = "print('pub static mut foofoo: ::std::os::raw::c_int;')"
         else:
@@ -74,8 +69,6 @@ else:
 import sys
 if "rust_is_available_bindgen_libclang.h" in " ".join(sys.argv):
     {libclang_case}
-elif "rust_is_available_bindgen_0_66.h" in " ".join(sys.argv):
-    {version_0_66_case}
 elif "rust_is_available_bindgen_libclang_concat.h" in " ".join(sys.argv):
     {libclang_concat_case}
 else:
@@ -83,8 +76,8 @@ else:
 """)
 
     @classmethod
-    def generate_bindgen_version(cls, stdout, version_0_66_patched=False):
-        return cls.generate_bindgen(stdout, cls.bindgen_default_bindgen_libclang_stderr, version_0_66_patched)
+    def generate_bindgen_version(cls, stdout):
+        return cls.generate_bindgen(stdout, cls.bindgen_default_bindgen_libclang_stderr)
 
     @classmethod
     def generate_bindgen_libclang_failure(cls):
@@ -245,19 +238,6 @@ else:
         result = self.run_script(self.Expected.FAILURE, { "BINDGEN": bindgen })
         self.assertIn(f"Rust bindings generator '{bindgen}' is too old.", result.stderr)
 
-    def test_bindgen_bad_version_0_66_0_and_0_66_1(self):
-        for version in ("0.66.0", "0.66.1"):
-            with self.subTest(version=version):
-                bindgen = self.generate_bindgen_version(f"bindgen {version}")
-                result = self.run_script(self.Expected.SUCCESS_WITH_WARNINGS, { "BINDGEN": bindgen })
-                self.assertIn(f"Rust bindings generator '{bindgen}' versions 0.66.0 and 0.66.1 may not", result.stderr)
-
-    def test_bindgen_bad_version_0_66_0_and_0_66_1_patched(self):
-        for version in ("0.66.0", "0.66.1"):
-            with self.subTest(version=version):
-                bindgen = self.generate_bindgen_version(f"bindgen {version}", True)
-                result = self.run_script(self.Expected.SUCCESS, { "BINDGEN": bindgen })
-
     def test_bindgen_libclang_failure(self):
         bindgen = self.generate_bindgen_libclang_failure()
         result = self.run_script(self.Expected.FAILURE, { "BINDGEN": bindgen })
-- 
2.53.0

[PATCH 16/33] rust: rust_is_available: remove warning for < 0.69.5 && libclang >= 19.1

[Miguel Ojeda]

It is not possible anymore to fall into the issue that this warning was
alerting about given the `bindgen` version bump.

Thus simplify by removing the machinery behind it, including tests.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 scripts/rust_is_available.sh                  | 15 --------
 ...ust_is_available_bindgen_libclang_concat.h |  3 --
 scripts/rust_is_available_test.py             | 34 +------------------
 3 files changed, 1 insertion(+), 51 deletions(-)
 delete mode 100644 scripts/rust_is_available_bindgen_libclang_concat.h

diff --git a/scripts/rust_is_available.sh b/scripts/rust_is_available.sh
index 77896e31dab5..cefc456c2503 100755
--- a/scripts/rust_is_available.sh
+++ b/scripts/rust_is_available.sh
@@ -214,21 +214,6 @@ if [ "$bindgen_libclang_cversion" -lt "$bindgen_libclang_min_cversion" ]; then
 	exit 1
 fi
 
-if [ "$bindgen_libclang_cversion" -ge 1900100 ] &&
-	[ "$rust_bindings_generator_cversion" -lt 6905 ]; then
-	# Distributions may have patched the issue (e.g. Debian did).
-	if ! "$BINDGEN" $(dirname $0)/rust_is_available_bindgen_libclang_concat.h | grep -q foofoo; then
-		echo >&2 "***"
-		echo >&2 "*** Rust bindings generator '$BINDGEN' < 0.69.5 together with libclang >= 19.1"
-		echo >&2 "*** may not work due to a bug (https://github.com/rust-lang/rust-bindgen/pull/2824),"
-		echo >&2 "*** unless patched (like Debian's)."
-		echo >&2 "***   Your bindgen version:  $rust_bindings_generator_version"
-		echo >&2 "***   Your libclang version: $bindgen_libclang_version"
-		echo >&2 "***"
-		warning=1
-	fi
-fi
-
 # If the C compiler is Clang, then we can also check whether its version
 # matches the `libclang` version used by the Rust bindings generator.
 #
diff --git a/scripts/rust_is_available_bindgen_libclang_concat.h b/scripts/rust_is_available_bindgen_libclang_concat.h
deleted file mode 100644
index efc6e98d0f1d..000000000000
--- a/scripts/rust_is_available_bindgen_libclang_concat.h
+++ /dev/null
@@ -1,3 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#define F(x) int x##x
-F(foo);
diff --git a/scripts/rust_is_available_test.py b/scripts/rust_is_available_test.py
index b66fa5933844..d6d54b7ea42a 100755
--- a/scripts/rust_is_available_test.py
+++ b/scripts/rust_is_available_test.py
@@ -54,23 +54,16 @@ else:
 """)
 
     @classmethod
-    def generate_bindgen(cls, version_stdout, libclang_stderr, libclang_concat_patched=False):
+    def generate_bindgen(cls, version_stdout, libclang_stderr):
         if libclang_stderr is None:
             libclang_case = f"raise SystemExit({cls.bindgen_default_bindgen_libclang_failure_exit_code})"
         else:
             libclang_case = f"print({repr(libclang_stderr)}, file=sys.stderr)"
 
-        if libclang_concat_patched:
-            libclang_concat_case = "print('pub static mut foofoo: ::std::os::raw::c_int;')"
-        else:
-            libclang_concat_case = "pass"
-
         return cls.generate_executable(f"""#!/usr/bin/env python3
 import sys
 if "rust_is_available_bindgen_libclang.h" in " ".join(sys.argv):
     {libclang_case}
-elif "rust_is_available_bindgen_libclang_concat.h" in " ".join(sys.argv):
-    {libclang_concat_case}
 else:
     print({repr(version_stdout)})
 """)
@@ -255,31 +248,6 @@ else:
         result = self.run_script(self.Expected.FAILURE, { "BINDGEN": bindgen })
         self.assertIn(f"libclang (used by the Rust bindings generator '{bindgen}') is too old.", result.stderr)
 
-    def test_bindgen_bad_libclang_concat(self):
-        for (bindgen_version, libclang_version, expected_not_patched) in (
-            ("0.69.4", "18.0.0", self.Expected.SUCCESS),
-            ("0.69.4", "19.1.0", self.Expected.SUCCESS_WITH_WARNINGS),
-            ("0.69.4", "19.2.0", self.Expected.SUCCESS_WITH_WARNINGS),
-
-            ("0.69.5", "18.0.0", self.Expected.SUCCESS),
-            ("0.69.5", "19.1.0", self.Expected.SUCCESS),
-            ("0.69.5", "19.2.0", self.Expected.SUCCESS),
-
-            ("0.70.0", "18.0.0", self.Expected.SUCCESS),
-            ("0.70.0", "19.1.0", self.Expected.SUCCESS),
-            ("0.70.0", "19.2.0", self.Expected.SUCCESS),
-        ):
-            with self.subTest(bindgen_version=bindgen_version, libclang_version=libclang_version):
-                cc = self.generate_clang(f"clang version {libclang_version}")
-                libclang_stderr = f"scripts/rust_is_available_bindgen_libclang.h:2:9: warning: clang version {libclang_version} [-W#pragma-messages], err: false"
-                bindgen = self.generate_bindgen(f"bindgen {bindgen_version}", libclang_stderr)
-                result = self.run_script(expected_not_patched, { "BINDGEN": bindgen, "CC": cc })
-                if expected_not_patched == self.Expected.SUCCESS_WITH_WARNINGS:
-                    self.assertIn(f"Rust bindings generator '{bindgen}' < 0.69.5 together with libclang >= 19.1", result.stderr)
-
-                bindgen = self.generate_bindgen(f"bindgen {bindgen_version}", libclang_stderr, libclang_concat_patched=True)
-                result = self.run_script(self.Expected.SUCCESS, { "BINDGEN": bindgen, "CC": cc })
-
     def test_clang_matches_bindgen_libclang_different_bindgen(self):
         bindgen = self.generate_bindgen_libclang("scripts/rust_is_available_bindgen_libclang.h:2:9: warning: clang version 999.0.0 [-W#pragma-messages], err: false")
         result = self.run_script(self.Expected.SUCCESS_WITH_WARNINGS, { "BINDGEN": bindgen })
-- 
2.53.0

[PATCH 17/33] rust: kbuild: update `bindgen --rust-target` version and replace comment

[Miguel Ojeda]

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.

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.

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

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/Makefile | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/rust/Makefile b/rust/Makefile
index 163d2258e93f..34f21b735993 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -446,22 +446,10 @@ endif
 # architecture instead of generating `usize`.
 bindgen_c_flags_final = $(bindgen_c_flags_lto) -fno-builtin -D__BINDGEN__
 
-# Each `bindgen` release may upgrade the list of Rust target versions. By
-# default, the highest stable release in their list is used. Thus we need to set
-# a `--rust-target` to avoid future `bindgen` releases emitting code that
-# `rustc` may not understand. On top of that, `bindgen` does not support passing
-# an unknown Rust target version.
-#
-# Therefore, the Rust target for `bindgen` can be only as high as the minimum
-# Rust version the kernel supports and only as high as the greatest stable Rust
-# target supported by the minimum `bindgen` version the kernel supports (that
-# is, if we do not test the actual `rustc`/`bindgen` versions running).
-#
-# Starting with `bindgen` 0.71.0, we will be able to set any future Rust version
-# instead, i.e. we will be able to set here our minimum supported Rust version.
+# `--rust-target` points to our minimum supported Rust version.
 quiet_cmd_bindgen = BINDGEN $@
       cmd_bindgen = \
-	$(BINDGEN) $< $(bindgen_target_flags) --rust-target 1.68 \
+	$(BINDGEN) $< $(bindgen_target_flags) --rust-target 1.85 \
 		--use-core --with-derive-default --ctypes-prefix ffi --no-layout-tests \
 		--no-debug '.*' --enable-function-attribute-detection \
 		-o $@ -- $(bindgen_c_flags_final) -DMODULE \
-- 
2.53.0

[PATCH 18/33] rust: kbuild: remove "dummy parameter" workaround for `bindgen` < 0.71.1

[Miguel Ojeda]

Until the version bump of `bindgen`, we needed to pass a dummy parameter
to avoid failing the `--version` call.

Thus remove it.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 init/Kconfig                 | 7 +------
 scripts/rust_is_available.sh | 8 +-------
 2 files changed, 2 insertions(+), 13 deletions(-)

diff --git a/init/Kconfig b/init/Kconfig
index f9fac458e4d4..d9b795f70a38 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -2211,12 +2211,7 @@ config RUSTC_VERSION_TEXT
 config BINDGEN_VERSION_TEXT
 	string
 	depends on RUST
-	# The dummy parameter `workaround-for-0.69.0` is required to support 0.69.0
-	# (https://github.com/rust-lang/rust-bindgen/pull/2678) and 0.71.0
-	# (https://github.com/rust-lang/rust-bindgen/pull/3040). It can be removed
-	# when the minimum version is upgraded past the latter (0.69.1 and 0.71.1
-	# both fixed the issue).
-	default "$(shell,$(BINDGEN) --version workaround-for-0.69.0 2>/dev/null)"
+	default "$(shell,$(BINDGEN) --version 2>/dev/null)"
 
 #
 # Place an empty function call at each tracepoint site. Can be
diff --git a/scripts/rust_is_available.sh b/scripts/rust_is_available.sh
index cefc456c2503..551f1ebd0dcb 100755
--- a/scripts/rust_is_available.sh
+++ b/scripts/rust_is_available.sh
@@ -121,14 +121,8 @@ fi
 # Check that the Rust bindings generator is suitable.
 #
 # Non-stable and distributions' versions may have a version suffix, e.g. `-dev`.
-#
-# The dummy parameter `workaround-for-0.69.0` is required to support 0.69.0
-# (https://github.com/rust-lang/rust-bindgen/pull/2678) and 0.71.0
-# (https://github.com/rust-lang/rust-bindgen/pull/3040). It can be removed when
-# the minimum version is upgraded past the latter (0.69.1 and 0.71.1 both fixed
-# the issue).
 rust_bindings_generator_output=$( \
-	LC_ALL=C "$BINDGEN" --version workaround-for-0.69.0 2>/dev/null
+	LC_ALL=C "$BINDGEN" --version 2>/dev/null
 ) || rust_bindings_generator_code=$?
 if [ -n "$rust_bindings_generator_code" ]; then
 	echo >&2 "***"
-- 
2.53.0

[PATCH 19/33] rust: kbuild: remove "`try` keyword" workaround for `bindgen` < 0.59.2

[Miguel Ojeda]

There is a workaround that has not been needed, even already after commit
08ab786556ff ("rust: bindgen: upgrade to 0.65.1"), but it does not hurt.

Thus remove it.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/bindgen_parameters | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/rust/bindgen_parameters b/rust/bindgen_parameters
index fd2fd1c3cb9a..112ec197ef0a 100644
--- a/rust/bindgen_parameters
+++ b/rust/bindgen_parameters
@@ -15,10 +15,6 @@
 --opaque-type x86_msi_data
 --opaque-type x86_msi_addr_lo
 
-# `try` is a reserved keyword since Rust 2018; solved in `bindgen` v0.59.2,
-# commit 2aed6b021680 ("context: Escape the try keyword properly").
---opaque-type kunit_try_catch
-
 # If SMP is disabled, `arch_spinlock_t` is defined as a ZST which triggers a Rust
 # warning. We don't need to peek into it anyway.
 --opaque-type spinlock
-- 
2.53.0

[PATCH 20/33] rust: kbuild: remove unneeded old `allow`s for generated layout tests

[Miguel Ojeda]

The issue that required `allow`s for `cfg(test)` code generated by
`bindgen` for layout testing was fixed back in `bindgen` 0.60.0 [1],
so it could have been removed even before the version bump, but it does
not hurt.

Thus remove it now.

Link: https://github.com/rust-lang/rust-bindgen/pull/2203 [1]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/bindings/lib.rs | 4 ----
 rust/uapi/lib.rs     | 4 ----
 2 files changed, 8 deletions(-)

diff --git a/rust/bindings/lib.rs b/rust/bindings/lib.rs
index 19f57c5b2fa2..e18c160dad17 100644
--- a/rust/bindings/lib.rs
+++ b/rust/bindings/lib.rs
@@ -9,10 +9,6 @@
 //! using this crate.
 
 #![no_std]
-// See <https://github.com/rust-lang/rust-bindgen/issues/1651>.
-#![cfg_attr(test, allow(deref_nullptr))]
-#![cfg_attr(test, allow(unaligned_references))]
-#![cfg_attr(test, allow(unsafe_op_in_unsafe_fn))]
 #![allow(
     clippy::all,
     missing_docs,
diff --git a/rust/uapi/lib.rs b/rust/uapi/lib.rs
index 1d5fd9efb93e..821e286e0daa 100644
--- a/rust/uapi/lib.rs
+++ b/rust/uapi/lib.rs
@@ -8,10 +8,6 @@
 //! userspace APIs.
 
 #![no_std]
-// See <https://github.com/rust-lang/rust-bindgen/issues/1651>.
-#![cfg_attr(test, allow(deref_nullptr))]
-#![cfg_attr(test, allow(unaligned_references))]
-#![cfg_attr(test, allow(unsafe_op_in_unsafe_fn))]
 #![allow(
     clippy::all,
     clippy::cast_lossless,
-- 
2.53.0

[PATCH 21/33] gpu: nova-core: bindings: remove unneeded `cfg_attr`

[Miguel Ojeda]

These were likely copied from the `bindings` and `uapi` crates, but are
unneeded since there are no `cfg(test)`s in the bindings.

In addition, the issue that triggered the addition in those crates
originally is also fixed in `bindgen` (please see the previous commit).

Thus remove them.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 drivers/gpu/nova-core/gsp/fw/r570_144.rs | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/gpu/nova-core/gsp/fw/r570_144.rs b/drivers/gpu/nova-core/gsp/fw/r570_144.rs
index e99d315ae74c..2e6f0d298756 100644
--- a/drivers/gpu/nova-core/gsp/fw/r570_144.rs
+++ b/drivers/gpu/nova-core/gsp/fw/r570_144.rs
@@ -7,9 +7,6 @@
 //! This module may not be directly used. Please abstract or re-export the needed symbols in the
 //! parent module instead.
 
-#![cfg_attr(test, allow(deref_nullptr))]
-#![cfg_attr(test, allow(unaligned_references))]
-#![cfg_attr(test, allow(unsafe_op_in_unsafe_fn))]
 #![allow(
     dead_code,
     clippy::all,
-- 
2.53.0

[PATCH 22/33] docs: rust: quick-start: openSUSE provides `rust-src` package nowadays

[Miguel Ojeda]

Both openSUSE Tumbleweed and Slowroll provide the `rust-src` package
nowadays [1].

Thus remove the version-specific one from the Quick Start guide.

Link: https://software.opensuse.org/package/rust-src?search_term=rust-src [1]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 Documentation/rust/quick-start.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/rust/quick-start.rst b/Documentation/rust/quick-start.rst
index 152289f0bed2..642efce04ee8 100644
--- a/Documentation/rust/quick-start.rst
+++ b/Documentation/rust/quick-start.rst
@@ -84,7 +84,7 @@ openSUSE
 openSUSE Slowroll and openSUSE Tumbleweed provide recent Rust releases and thus
 they should generally work out of the box, e.g.::
 
-	zypper install rust rust1.79-src rust-bindgen clang
+	zypper install rust rust-src rust-bindgen clang
 
 
 Ubuntu
-- 
2.53.0

[PATCH 23/33] docs: rust: quick-start: update Ubuntu versioned packages

[Miguel Ojeda]

Now that the minimum supported Rust version is bumped, bump the versioned
Rust packages [1][2][3][4] to that version for Ubuntu in the Quick
Start guide.

In addition, add "may" to the `RUST_LIB_SRC` line since it does not look
like it is needed from a quick test in a Ubuntu 24.04 LTS container.

Link: https://packages.ubuntu.com/search?suite=all&searchon=names&keywords=rustc [1]
Link: https://packages.ubuntu.com/search?suite=all&searchon=names&keywords=bindgen [2]
Link: https://launchpad.net/ubuntu/+source/rustc-1.85 [3]
Link: https://launchpad.net/ubuntu/+source/rust-bindgen-0.71 [4]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 Documentation/rust/quick-start.rst | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/Documentation/rust/quick-start.rst b/Documentation/rust/quick-start.rst
index 642efce04ee8..54fe491deb7d 100644
--- a/Documentation/rust/quick-start.rst
+++ b/Documentation/rust/quick-start.rst
@@ -112,33 +112,33 @@ Though Ubuntu 24.04 LTS and older versions still provide recent Rust
 releases, they require some additional configuration to be set, using
 the versioned packages, e.g.::
 
-	apt install rustc-1.80 rust-1.80-src bindgen-0.65 rustfmt-1.80 \
-		rust-1.80-clippy
-	ln -s /usr/lib/rust-1.80/bin/rustfmt /usr/bin/rustfmt-1.80
-	ln -s /usr/lib/rust-1.80/bin/clippy-driver /usr/bin/clippy-driver-1.80
+	apt install rustc-1.85 rust-1.85-src bindgen-0.71 rustfmt-1.85 \
+		rust-1.85-clippy
+	ln -s /usr/lib/rust-1.85/bin/rustfmt /usr/bin/rustfmt-1.85
+	ln -s /usr/lib/rust-1.85/bin/clippy-driver /usr/bin/clippy-driver-1.85
 
 None of these packages set their tools as defaults; therefore they should be
 specified explicitly, e.g.::
 
-	make LLVM=1 RUSTC=rustc-1.80 RUSTDOC=rustdoc-1.80 RUSTFMT=rustfmt-1.80 \
-		CLIPPY_DRIVER=clippy-driver-1.80 BINDGEN=bindgen-0.65
+	make LLVM=1 RUSTC=rustc-1.85 RUSTDOC=rustdoc-1.85 RUSTFMT=rustfmt-1.85 \
+		CLIPPY_DRIVER=clippy-driver-1.85 BINDGEN=bindgen-0.71
 
-Alternatively, modify the ``PATH`` variable to place the Rust 1.80 binaries
+Alternatively, modify the ``PATH`` variable to place the Rust 1.85 binaries
 first and set ``bindgen`` as the default, e.g.::
 
-	PATH=/usr/lib/rust-1.80/bin:$PATH
+	PATH=/usr/lib/rust-1.85/bin:$PATH
 	update-alternatives --install /usr/bin/bindgen bindgen \
-		/usr/bin/bindgen-0.65 100
-	update-alternatives --set bindgen /usr/bin/bindgen-0.65
+		/usr/bin/bindgen-0.71 100
+	update-alternatives --set bindgen /usr/bin/bindgen-0.71
 
-``RUST_LIB_SRC`` needs to be set when using the versioned packages, e.g.::
+``RUST_LIB_SRC`` may need to be set when using the versioned packages, e.g.::
 
-	RUST_LIB_SRC=/usr/src/rustc-$(rustc-1.80 --version | cut -d' ' -f2)/library
+	RUST_LIB_SRC=/usr/src/rustc-$(rustc-1.85 --version | cut -d' ' -f2)/library
 
 For convenience, ``RUST_LIB_SRC`` can be exported to the global environment.
 
-In addition, ``bindgen-0.65`` is available in newer releases (24.04 LTS and
-24.10), but it may not be available in older ones (20.04 LTS and 22.04 LTS),
+In addition, ``bindgen-0.71`` is available in newer releases (24.04 LTS),
+but it may not be available in older ones (20.04 LTS and 22.04 LTS),
 thus ``bindgen`` may need to be built manually (please see below).
 
 
-- 
2.53.0

[PATCH 24/33] docs: rust: quick-start: update minimum Ubuntu version

[Miguel Ojeda]

Ubuntu 25.04 is out of support [1], and Ubuntu 25.10 is the latest
supported one.

Moreover, Ubuntu 25.10 is the first that provides a recent enough Rust
given the minimum bump -- they provide 1.85.1 [2].

Thus update it.

Link: https://ubuntu.com/about/release-cycle [1]
Link: https://packages.ubuntu.com/search?keywords=rustc&searchon=names&exact=1&suite=all&section=all [2]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 Documentation/rust/quick-start.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/rust/quick-start.rst b/Documentation/rust/quick-start.rst
index 54fe491deb7d..34c39f208333 100644
--- a/Documentation/rust/quick-start.rst
+++ b/Documentation/rust/quick-start.rst
@@ -90,7 +90,7 @@ they should generally work out of the box, e.g.::
 Ubuntu
 ******
 
-25.04
+25.10
 ~~~~~
 
 The latest Ubuntu releases provide recent Rust releases and thus they should
-- 
2.53.0

[PATCH 25/33] docs: rust: quick-start: add Ubuntu 26.04 LTS and remove subsection title

[Miguel Ojeda]

Ubuntu 26.04 LTS (Resolute Raccoon) is scheduled to be released in a few
weeks [1], and it has a recent enough Rust toolchain, just like Ubuntu
25.10 has [2][3].

We could update the title and the paragraph, but to simplify and to
make it more consistent with the other distributions' sections, let's
instead just remove that title. It will also reduce the differences
later on to keep it updated. Eventually, when we remove the remaining
subsection for older LTSs, Ubuntu should be a small section like the
other distributions.

Thus remove the title and add the mention of Ubuntu 26.04 LTS.

Link: https://documentation.ubuntu.com/release-notes/26.04/schedule/#resolute-raccoon-schedule [1]
Link: https://packages.ubuntu.com/search?keywords=rustc&searchon=names&exact=1&suite=all&section=all [2]
Link: https://packages.ubuntu.com/search?keywords=bindgen&searchon=names&exact=1&suite=all&section=all [3]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 Documentation/rust/quick-start.rst | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/Documentation/rust/quick-start.rst b/Documentation/rust/quick-start.rst
index 34c39f208333..db08c3a03a4f 100644
--- a/Documentation/rust/quick-start.rst
+++ b/Documentation/rust/quick-start.rst
@@ -90,10 +90,7 @@ they should generally work out of the box, e.g.::
 Ubuntu
 ******
 
-25.10
-~~~~~
-
-The latest Ubuntu releases provide recent Rust releases and thus they should
+Ubuntu 25.10 and 26.04 LTS provide recent Rust releases and thus they should
 generally work out of the box, e.g.::
 
 	apt install rustc rust-src bindgen rustfmt rust-clippy
-- 
2.53.0

[PATCH 26/33] docs: rust: quick-start: remove Gentoo "testing" note

[Miguel Ojeda]

Gentoo does not need the "testing" note, since its packages are recent
enough even in the stable branch [1][2].

Thus remove it to simplify the documentation.

Link: https://packages.gentoo.org/packages/dev-lang/rust [1]
Link: https://packages.gentoo.org/packages/dev-util/bindgen [2]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 Documentation/rust/quick-start.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/rust/quick-start.rst b/Documentation/rust/quick-start.rst
index db08c3a03a4f..1518367324fe 100644
--- a/Documentation/rust/quick-start.rst
+++ b/Documentation/rust/quick-start.rst
@@ -57,8 +57,8 @@ of the box, e.g.::
 Gentoo Linux
 ************
 
-Gentoo Linux (and especially the testing branch) provides recent Rust releases
-and thus it should generally work out of the box, e.g.::
+Gentoo Linux provides recent Rust releases and thus it should generally work out
+of the box, e.g.::
 
 	USE='rust-src rustfmt clippy' emerge dev-lang/rust dev-util/bindgen
 
-- 
2.53.0

[PATCH 27/33] docs: rust: quick-start: remove Nix "unstable channel" note

[Miguel Ojeda]

Nix does not need the "unstable channel" note, since its packages are
recent enough even in the stable channel [1][2].

Thus remove it to simplify the documentation.

Link: https://search.nixos.org/packages?channel=25.11&query=rust [1]
Link: https://search.nixos.org/packages?channel=25.11&query=bindgen [2]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 Documentation/rust/quick-start.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/rust/quick-start.rst b/Documentation/rust/quick-start.rst
index 1518367324fe..5bbe059a8fa3 100644
--- a/Documentation/rust/quick-start.rst
+++ b/Documentation/rust/quick-start.rst
@@ -68,8 +68,8 @@ of the box, e.g.::
 Nix
 ***
 
-Nix (unstable channel) provides recent Rust releases and thus it should
-generally work out of the box, e.g.::
+Nix provides recent Rust releases and thus it should generally work out of the
+box, e.g.::
 
 	{ pkgs ? import <nixpkgs> {} }:
 	pkgs.mkShell {
-- 
2.53.0

[PATCH 28/33] docs: rust: quick-start: remove GDB/Binutils mention

[Miguel Ojeda]

The versions provided nowadays by even a distribution like Debian Stable
(and Debian Old Stable) are newer than those mentioned [1].

Thus remove the workaround.

Note that the minimum binutils version in the kernel is still 2.30, so
one could argue part of the note is still relevant, but it is unlikely
a kernel developer using such an old binutils is enabling Rust on a
modern kernel, especially when using distribution toolchains, e.g. the
Rust minimum version is not satisfied by Debian Old Stable.

So we are at the point where keeping the docs short and relevant for
essentially everyone is probably the better trade-off.

Link: https://packages.debian.org/search?suite=all&searchon=names&keywords=binutils [1]
Link: https://lore.kernel.org/all/CANiq72mCpc9=2TN_zC4NeDMpFQtPXAFvyiP+gRApg2vzspPWmw@mail.gmail.com/
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 Documentation/rust/quick-start.rst | 9 ---------
 1 file changed, 9 deletions(-)

diff --git a/Documentation/rust/quick-start.rst b/Documentation/rust/quick-start.rst
index 5bbe059a8fa3..a6ec3fa94d33 100644
--- a/Documentation/rust/quick-start.rst
+++ b/Documentation/rust/quick-start.rst
@@ -352,12 +352,3 @@ Hacking
 To dive deeper, take a look at the source code of the samples
 at ``samples/rust/``, the Rust support code under ``rust/`` and
 the ``Rust hacking`` menu under ``Kernel hacking``.
-
-If GDB/Binutils is used and Rust symbols are not getting demangled, the reason
-is the toolchain does not support Rust's new v0 mangling scheme yet.
-There are a few ways out:
-
-- Install a newer release (GDB >= 10.2, Binutils >= 2.36).
-
-- Some versions of GDB (e.g. vanilla GDB 10.1) are able to use
-  the pre-demangled names embedded in the debug info (``CONFIG_DEBUG_INFO``).
-- 
2.53.0

[PATCH 29/33] docs: rust: general-information: simplify Kconfig example

[Miguel Ojeda]

There is no need to use `def_bool y if <expr>` -- one can simply write
`def_bool <expr>`.

In fact, the simpler form is how we actually use them in practice in
`init/Kconfig`.

Thus simplify the example.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 Documentation/rust/general-information.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/rust/general-information.rst b/Documentation/rust/general-information.rst
index 6146b49b6a98..91535b2306ed 100644
--- a/Documentation/rust/general-information.rst
+++ b/Documentation/rust/general-information.rst
@@ -158,4 +158,4 @@ numerical comparisons, one may define a new Kconfig symbol:
 .. code-block:: kconfig
 
 	config RUSTC_VERSION_MIN_107900
-		def_bool y if RUSTC_VERSION >= 107900
+		def_bool RUSTC_VERSION >= 107900
-- 
2.53.0

[PATCH 30/33] docs: rust: general-information: use real example

[Miguel Ojeda]

Currently the example in the documentation shows a version-based name
for the Kconfig example:

    RUSTC_VERSION_MIN_107900

The reason behind it was to possibly avoid repetition in case several
features used the same minimum.

However, we ended up preferring to give them a descriptive name for each
feature added even if that could lead to some repetition. In practice,
the repetition has not happened so far, and even if it does at some point,
it is not a big deal.

Thus replace the example in the documentation with one of our current
examples (after removing previous ones from the bump), to show how they
actually look like, and in case someone `grep`s for it.

In addition, it has the advantage that it shows the `RUSTC_HAS_*`
pattern we follow in `init/Kconfig`, similar to the C side.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 Documentation/rust/general-information.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/rust/general-information.rst b/Documentation/rust/general-information.rst
index 91535b2306ed..09234bed272c 100644
--- a/Documentation/rust/general-information.rst
+++ b/Documentation/rust/general-information.rst
@@ -157,5 +157,5 @@ numerical comparisons, one may define a new Kconfig symbol:
 
 .. code-block:: kconfig
 
-	config RUSTC_VERSION_MIN_107900
-		def_bool RUSTC_VERSION >= 107900
+	config RUSTC_HAS_SPAN_FILE
+		def_bool RUSTC_VERSION >= 108800
-- 
2.53.0

[PATCH 31/33] rust: declare cfi_encoding for lru_status

[Miguel Ojeda]

From: Alice Ryhl <aliceryhl@google.com>

By default bindgen will convert 'enum lru_status' into a typedef for an
integer. For the most part, an integer of the same size as the enum
results in the correct ABI, but in the specific case of CFI, that is not
the case. The CFI encoding is supposed to be the same as a struct called
'lru_status' rather than the name of the underlying native integer type.

To fix this, tell bindgen to generate a newtype and set the CFI type
explicitly. Note that we need to set the CFI attribute explicitly as
bindgen is using repr(transparent), which is otherwise identical to the
inner type for ABI purposes.

This allows us to remove the page range helper C function in Binder
without risking a CFI failure when list_lru_walk calls the provided
function pointer.

The --with-attribute-custom-enum argument requires bindgen v0.71 or
greater.

[ In particular, the feature was added in 0.71.0 [1][2].

  In addition, `feature(cfi_encoding)` has been available since
  Rust 1.71.0 [3].

  Link: https://github.com/rust-lang/rust-bindgen/issues/2520 [1]
  Link: https://github.com/rust-lang/rust-bindgen/pull/2866 [2]
  Link: https://github.com/rust-lang/rust/pull/105452 [3]

    - Miguel ]

My testing procedure was to add this to the android17-6.18 branch and
verify that rust_shrink_free_page is successfully called without crash,
and verify that it does in fact crash when the cfi_encoding is set to
other values. Note that I couldn't test this on android16-6.12 as that
branch uses a bindgen version that is too old.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260223-cfi-lru-status-v2-1-89c6448a63a4@google.com
[ Rebased on top of the minimum Rust version bump series which provide
  the required `bindgen` version. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 drivers/android/binder/Makefile            |  3 +--
 drivers/android/binder/page_range.rs       |  6 +++---
 drivers/android/binder/page_range_helper.c | 24 ----------------------
 drivers/android/binder/page_range_helper.h | 15 --------------
 rust/bindgen_parameters                    |  4 ++++
 rust/bindings/bindings_helper.h            |  1 -
 rust/bindings/lib.rs                       |  1 +
 rust/uapi/lib.rs                           |  1 +
 8 files changed, 10 insertions(+), 45 deletions(-)
 delete mode 100644 drivers/android/binder/page_range_helper.c
 delete mode 100644 drivers/android/binder/page_range_helper.h

diff --git a/drivers/android/binder/Makefile b/drivers/android/binder/Makefile
index 09eabb527fa0..7e0cd9782a8b 100644
--- a/drivers/android/binder/Makefile
+++ b/drivers/android/binder/Makefile
@@ -5,5 +5,4 @@ obj-$(CONFIG_ANDROID_BINDER_IPC_RUST) += rust_binder.o
 rust_binder-y := \
 	rust_binder_main.o	\
 	rust_binderfs.o		\
-	rust_binder_events.o	\
-	page_range_helper.o
+	rust_binder_events.o
diff --git a/drivers/android/binder/page_range.rs b/drivers/android/binder/page_range.rs
index fdd97112ef5c..8e9f5c4819d0 100644
--- a/drivers/android/binder/page_range.rs
+++ b/drivers/android/binder/page_range.rs
@@ -642,15 +642,15 @@ fn drop(self: Pin<&mut Self>) {
     unsafe {
         bindings::list_lru_walk(
             list_lru,
-            Some(bindings::rust_shrink_free_page_wrap),
+            Some(rust_shrink_free_page),
             ptr::null_mut(),
             nr_to_scan,
         )
     }
 }
 
-const LRU_SKIP: bindings::lru_status = bindings::lru_status_LRU_SKIP;
-const LRU_REMOVED_ENTRY: bindings::lru_status = bindings::lru_status_LRU_REMOVED_RETRY;
+const LRU_SKIP: bindings::lru_status = bindings::lru_status::LRU_SKIP;
+const LRU_REMOVED_ENTRY: bindings::lru_status = bindings::lru_status::LRU_REMOVED_RETRY;
 
 /// # Safety
 /// Called by the shrinker.
diff --git a/drivers/android/binder/page_range_helper.c b/drivers/android/binder/page_range_helper.c
deleted file mode 100644
index 496887723ee0..000000000000
--- a/drivers/android/binder/page_range_helper.c
+++ /dev/null
@@ -1,24 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-
-/* C helper for page_range.rs to work around a CFI violation.
- *
- * Bindgen currently pretends that `enum lru_status` is the same as an integer.
- * This assumption is fine ABI-wise, but once you add CFI to the mix, it
- * triggers a CFI violation because `enum lru_status` gets a different CFI tag.
- *
- * This file contains a workaround until bindgen can be fixed.
- *
- * Copyright (C) 2025 Google LLC.
- */
-#include "page_range_helper.h"
-
-unsigned int rust_shrink_free_page(struct list_head *item,
-				   struct list_lru_one *list,
-				   void *cb_arg);
-
-enum lru_status
-rust_shrink_free_page_wrap(struct list_head *item, struct list_lru_one *list,
-			   void *cb_arg)
-{
-	return rust_shrink_free_page(item, list, cb_arg);
-}
diff --git a/drivers/android/binder/page_range_helper.h b/drivers/android/binder/page_range_helper.h
deleted file mode 100644
index 18dd2dd117b2..000000000000
--- a/drivers/android/binder/page_range_helper.h
+++ /dev/null
@@ -1,15 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Copyright (C) 2025 Google, Inc.
- */
-
-#ifndef _LINUX_PAGE_RANGE_HELPER_H
-#define _LINUX_PAGE_RANGE_HELPER_H
-
-#include <linux/list_lru.h>
-
-enum lru_status
-rust_shrink_free_page_wrap(struct list_head *item, struct list_lru_one *list,
-			   void *cb_arg);
-
-#endif /* _LINUX_PAGE_RANGE_HELPER_H */
diff --git a/rust/bindgen_parameters b/rust/bindgen_parameters
index 112ec197ef0a..6f02d9720ad2 100644
--- a/rust/bindgen_parameters
+++ b/rust/bindgen_parameters
@@ -19,6 +19,10 @@
 # warning. We don't need to peek into it anyway.
 --opaque-type spinlock
 
+# enums that appear in indirect function calls should specify a cfi type
+--newtype-enum lru_status
+--with-attribute-custom-enum=lru_status='#[cfi_encoding="10lru_status"]'
+
 # `seccomp`'s comment gets understood as a doctest
 --no-doc-comments
 
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index 083cc44aa952..faf3ee634ced 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -149,5 +149,4 @@ const vm_flags_t RUST_CONST_HELPER_VM_NOHUGEPAGE = VM_NOHUGEPAGE;
 #if IS_ENABLED(CONFIG_ANDROID_BINDER_IPC_RUST)
 #include "../../drivers/android/binder/rust_binder.h"
 #include "../../drivers/android/binder/rust_binder_events.h"
-#include "../../drivers/android/binder/page_range_helper.h"
 #endif
diff --git a/rust/bindings/lib.rs b/rust/bindings/lib.rs
index e18c160dad17..854e7c471434 100644
--- a/rust/bindings/lib.rs
+++ b/rust/bindings/lib.rs
@@ -19,6 +19,7 @@
     unreachable_pub,
     unsafe_op_in_unsafe_fn
 )]
+#![feature(cfi_encoding)]
 
 #[allow(dead_code)]
 #[allow(clippy::cast_lossless)]
diff --git a/rust/uapi/lib.rs b/rust/uapi/lib.rs
index 821e286e0daa..b8a515de31ca 100644
--- a/rust/uapi/lib.rs
+++ b/rust/uapi/lib.rs
@@ -24,6 +24,7 @@
     unsafe_op_in_unsafe_fn
 )]
 #![cfg_attr(CONFIG_RUSTC_HAS_UNNECESSARY_TRANSMUTES, allow(unnecessary_transmutes))]
+#![feature(cfi_encoding)]
 
 // Manual definition of blocklisted types.
 type __kernel_size_t = usize;
-- 
2.53.0

[PATCH 32/33] rust: kbuild: support global per-version flags

[Miguel Ojeda]

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`.

An alternative is moving all those three down, but that would mean
separating them from the other `KBUILD_*` variables.

Link: https://lore.kernel.org/rust-for-linux/CANiq72mWdFU11GcCZRchzhy0Gi1QZShvZtyRkHV2O+WA2uTdVQ@mail.gmail.com/ [1]
Link: https://patch.msgid.link/20260307170929.153892-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 Makefile | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Makefile b/Makefile
index 1a219bf1c771..20c8179d96ee 100644
--- a/Makefile
+++ b/Makefile
@@ -834,6 +834,14 @@ endif # CONFIG_TRACEPOINTS
 
 export WARN_ON_UNUSED_TRACEPOINTS
 
+# Per-version Rust flags. These are like `rust_common_flags`, but may
+# depend on the Rust compiler version (e.g. using `rustc-min-version`).
+rust_common_flags_per_version :=
+
+rust_common_flags += $(rust_common_flags_per_version)
+KBUILD_HOSTRUSTFLAGS += $(rust_common_flags_per_version)
+KBUILD_RUSTFLAGS += $(rust_common_flags_per_version)
+
 include $(srctree)/arch/$(SRCARCH)/Makefile
 
 ifdef need-config
-- 
2.53.0

[PATCH 33/33] rust: kbuild: allow `clippy::precedence` for Rust < 1.86.0

[Miguel Ojeda]

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)
       |

    warning: operator precedence can trip the unwary
       --> drivers/gpu/nova-core/vbios.rs:511:17
        |
    511 | /                 u32::from(data[29]) << 24
    512 | |                     | u32::from(data[28]) << 16
    513 | |                     | u32::from(data[27]) << 8
        | |______________________________________________^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#precedence
    help: consider parenthesizing your expression
        |
    511 ~                 u32::from(data[29]) << 24
    512 +                     | u32::from(data[28]) << 16 | (u32::from(data[27]) << 8)
        |

    warning: operator precedence can trip the unwary
       --> drivers/gpu/nova-core/vbios.rs:511:17
        |
    511 | /                 u32::from(data[29]) << 24
    512 | |                     | u32::from(data[28]) << 16
        | |_______________________________________________^ help: consider parenthesizing your expression: `(u32::from(data[29]) << 24) | (u32::from(data[28]) << 16)`
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#precedence

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 "false positives"
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]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 20c8179d96ee..a0d6ed050c8a 100644
--- a/Makefile
+++ b/Makefile
@@ -836,7 +836,8 @@ export WARN_ON_UNUSED_TRACEPOINTS
 
 # Per-version Rust flags. These are like `rust_common_flags`, but may
 # depend on the Rust compiler version (e.g. using `rustc-min-version`).
-rust_common_flags_per_version :=
+rust_common_flags_per_version := \
+    $(if $(call rustc-min-version,108600),,-Aclippy::precedence)
 
 rust_common_flags += $(rust_common_flags_per_version)
 KBUILD_HOSTRUSTFLAGS += $(rust_common_flags_per_version)
-- 
2.53.0

Re: [PATCH 01/33] rust: bump Rust minimum supported version to 1.85.0 (Debian Trixie)

[Alice Ryhl]

On Wed, Apr 01, 2026 at 01:45:08PM +0200, Miguel Ojeda wrote:
> 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 really *should* pick up 1.85.1. It contains bugfixes serious
enough that the Rust team decided it was reasonble to release a point
release.

> Debian Trixie's release happened on 2025-08-09 [4], 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 version.
> 
> Then, in later commits, clean up most of the workarounds and other bits
> that this upgrade of the minimum allows us.
> 
> pin-init was left as-is since the patches come from upstream. And the
> vendored crates are unmodified, since we do not want to change those.
> 
> Note that the minimum LLVM major version for Rust 1.85.0 is LLVM 18 (the
> Rust upstream binaries use LLVM 19.1.7), thus e.g. `RUSTC_LLVM_VERSION`
> tests can also be updated, but there are no suitable ones to simplify.
> 
> Ubuntu 25.10 also has a recent enough Rust toolchain [5], and they also
> provide versioned packages with a Rust 1.85.1 toolchain even back to
> Ubuntu 22.04 LTS [6].
> 
> 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://www.debian.org/releases/trixie/ [4]
> Link: https://packages.ubuntu.com/search?suite=all&searchon=names&keywords=rustc [5]
> Link: https://launchpad.net/ubuntu/+source/rustc-1.85 [6]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Acked-by: Alice Ryhl <aliceryhl@google.com>

Re: [PATCH 01/33] rust: bump Rust minimum supported version to 1.85.0 (Debian Trixie)

[Danilo Krummrich]

On Wed Apr 1, 2026 at 1:45 PM CEST, Miguel Ojeda wrote:
> 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's release happened on 2025-08-09 [4], 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 version.
>
> Then, in later commits, clean up most of the workarounds and other bits
> that this upgrade of the minimum allows us.
>
> pin-init was left as-is since the patches come from upstream. And the
> vendored crates are unmodified, since we do not want to change those.
>
> Note that the minimum LLVM major version for Rust 1.85.0 is LLVM 18 (the
> Rust upstream binaries use LLVM 19.1.7), thus e.g. `RUSTC_LLVM_VERSION`
> tests can also be updated, but there are no suitable ones to simplify.
>
> Ubuntu 25.10 also has a recent enough Rust toolchain [5], and they also
> provide versioned packages with a Rust 1.85.1 toolchain even back to
> Ubuntu 22.04 LTS [6].
>
> 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://www.debian.org/releases/trixie/ [4]
> Link: https://packages.ubuntu.com/search?suite=all&searchon=names&keywords=rustc [5]
> Link: https://launchpad.net/ubuntu/+source/rustc-1.85 [6]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Acked-by: Danilo Krummrich <dakr@kernel.org>

Re: [PATCH 11/33] rust: alloc: simplify with `NonNull::add()` now that it is stable

[Danilo Krummrich]

On Wed Apr 1, 2026 at 1:45 PM CEST, Miguel Ojeda wrote:
> Currently we need to go through raw pointers and then re-create the
> `NonNull` from the result of offsetting the raw pointer.
>
> Thus, now that we bump the Rust minimum version, simplify using
> `NonNull::add()` and clean the TODO note.
>
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Acked-by: Danilo Krummrich <dakr@kernel.org>

Re: [PATCH 21/33] gpu: nova-core: bindings: remove unneeded `cfg_attr`

[Danilo Krummrich]

On Wed Apr 1, 2026 at 1:45 PM CEST, Miguel Ojeda wrote:
> These were likely copied from the `bindings` and `uapi` crates, but are
> unneeded since there are no `cfg(test)`s in the bindings.
>
> In addition, the issue that triggered the addition in those crates
> originally is also fixed in `bindgen` (please see the previous commit).
>
> Thus remove them.
>
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Acked-by: Danilo Krummrich <dakr@kernel.org>

Re: [PATCH 01/33] rust: bump Rust minimum supported version to 1.85.0 (Debian Trixie)

[Miguel Ojeda]

On Wed, Apr 1, 2026 at 2:25 PM Alice Ryhl <aliceryhl@google.com> wrote:
>
> Debian really *should* pick up 1.85.1. It contains bugfixes serious
> enough that the Rust team decided it was reasonble to release a point
> release.

I asked them about their policy yesterday here:

  https://lore.kernel.org/rust-for-linux/20260331190053.482607-1-ojeda@kernel.org/

Perhaps they just prefer to apply patches on top.

The issue linked above is the only one I noticed so far, and it is
quite specific.

Anyway, it is up to them.

Cheers,
Miguel

Re: [PATCH 01/33] rust: bump Rust minimum supported version to 1.85.0 (Debian Trixie)

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> 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's release happened on 2025-08-09 [4], 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 version.
> 
> Then, in later commits, clean up most of the workarounds and other bits
> that this upgrade of the minimum allows us.
> 
> pin-init was left as-is since the patches come from upstream. And the
> vendored crates are unmodified, since we do not want to change those.
> 
> Note that the minimum LLVM major version for Rust 1.85.0 is LLVM 18 (the
> Rust upstream binaries use LLVM 19.1.7), thus e.g. `RUSTC_LLVM_VERSION`
> tests can also be updated, but there are no suitable ones to simplify.
> 
> Ubuntu 25.10 also has a recent enough Rust toolchain [5], and they also
> provide versioned packages with a Rust 1.85.1 toolchain even back to
> Ubuntu 22.04 LTS [6].
> 
> 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://www.debian.org/releases/trixie/ [4]
> Link: https://packages.ubuntu.com/search?suite=all&searchon=names&keywords=rustc [5]
> Link: https://launchpad.net/ubuntu/+source/rustc-1.85 [6]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Acked-by: Gary Guo <gary@garyguo.net>

> ---
>  Documentation/process/changes.rst | 2 +-
>  scripts/min-tool-version.sh       | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)

Re: [PATCH 02/33] rust: bump Clippy's MSRV and clean `incompatible_msrv` allows

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> Following the Rust compiler bump, we can now update Clippy's MSRV we
> set in the configuration, which will improve the diagnostics it generates.
> 
> Thus do so and clean a few of the `allow`s that are not needed anymore.
> 
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  .clippy.toml                      | 2 +-
>  drivers/gpu/nova-core/gsp/cmdq.rs | 6 +-----
>  rust/kernel/ptr.rs                | 1 -
>  rust/kernel/transmute.rs          | 2 --
>  4 files changed, 2 insertions(+), 9 deletions(-)

Re: [PATCH 03/33] rust: simplify `RUSTC_VERSION` Kconfig conditions

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> With the Rust version bump in place, several Kconfig conditions based on
> `RUSTC_VERSION` are always true.
> 
> Thus simplify them.
> 
> The minimum supported major LLVM version by our new Rust minimum version
> is now LLVM 18, instead of LLVM 16. However, there are no possible
> cleanups for `RUSTC_LLVM_VERSION`.
> 
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  arch/Kconfig       | 3 +--
>  arch/arm64/Kconfig | 8 --------
>  arch/riscv/Kconfig | 3 ---
>  init/Kconfig       | 2 --
>  4 files changed, 1 insertion(+), 15 deletions(-)

Re: [PATCH 04/33] rust: remove `RUSTC_HAS_SLICE_AS_FLATTENED` and simplify code

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> With the Rust version bump in place, the `RUSTC_HAS_SLICE_AS_FLATTENED`
> Kconfig (automatic) option is always true.
> 
> Thus remove the option and simplify the code.
> 
> In particular, this includes removing the `slice` module which contained
> the temporary slice helpers, i.e. the `AsFlattened` extension trait and
> its `impl`s.
> 
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  init/Kconfig           |  3 ---
>  rust/kernel/lib.rs     |  1 -
>  rust/kernel/prelude.rs |  3 ---
>  rust/kernel/slice.rs   | 49 ------------------------------------------
>  4 files changed, 56 deletions(-)
>  delete mode 100644 rust/kernel/slice.rs

Re: [PATCH 01/33] rust: bump Rust minimum supported version to 1.85.0 (Debian Trixie)

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> 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's release happened on 2025-08-09 [4], 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 version.
>
> Then, in later commits, clean up most of the workarounds and other bits
> that this upgrade of the minimum allows us.
>
> pin-init was left as-is since the patches come from upstream. And the
> vendored crates are unmodified, since we do not want to change those.
>
> Note that the minimum LLVM major version for Rust 1.85.0 is LLVM 18 (the
> Rust upstream binaries use LLVM 19.1.7), thus e.g. `RUSTC_LLVM_VERSION`
> tests can also be updated, but there are no suitable ones to simplify.
>
> Ubuntu 25.10 also has a recent enough Rust toolchain [5], and they also
> provide versioned packages with a Rust 1.85.1 toolchain even back to
> Ubuntu 22.04 LTS [6].
>
> 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://www.debian.org/releases/trixie/ [4]
> Link: https://packages.ubuntu.com/search?suite=all&searchon=names&keywords=rustc [5]
> Link: https://launchpad.net/ubuntu/+source/rustc-1.85 [6]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
> ---
>  Documentation/process/changes.rst | 2 +-
>  scripts/min-tool-version.sh       | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst
> index 6b373e193548..474594bd4831 100644
> --- a/Documentation/process/changes.rst
> +++ b/Documentation/process/changes.rst

This diff fails to apply on linux-next, due to conflict with ece7e57afd51
("docs: changes.rst and ver_linux: sort the lists").

Best,
Gary

> @@ -31,7 +31,7 @@ you probably needn't concern yourself with pcmciautils.
>  ====================== ===============  ========================================
>  GNU C                  8.1              gcc --version
>  Clang/LLVM (optional)  15.0.0           clang --version
> -Rust (optional)        1.78.0           rustc --version
> +Rust (optional)        1.85.0           rustc --version
>  bindgen (optional)     0.65.1           bindgen --version
>  GNU make               4.0              make --version
>  bash                   4.2              bash --version
> diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh
> index 99b5575c1ef7..a270ec761f64 100755
> --- a/scripts/min-tool-version.sh
> +++ b/scripts/min-tool-version.sh
> @@ -31,7 +31,7 @@ llvm)
>  	fi
>  	;;
>  rustc)
> -	echo 1.78.0
> +	echo 1.85.0
>  	;;
>  bindgen)
>  	echo 0.65.1

Re: [PATCH 01/33] rust: bump Rust minimum supported version to 1.85.0 (Debian Trixie)

[Miguel Ojeda]

On Wed, Apr 1, 2026 at 3:28 PM Gary Guo <gary@garyguo.net> wrote:
>
> This diff fails to apply on linux-next, due to conflict with ece7e57afd51
> ("docs: changes.rst and ver_linux: sort the lists").

Yeah, sorry, I should have added `--base-commit` -- it is `rust-next`,
i.e. 3a2486cc1da5 ("kbuild: rust: provide an option to inline C
helpers into Rust").

There will be other conflicts too, e.g. in the list of features in
`scripts/Makefile.build`.

Cheers,
Miguel

Re: [PATCH 05/33] rust: remove `RUSTC_HAS_COERCE_POINTEE` and simplify code

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> With the Rust version bump in place, the `RUSTC_HAS_COERCE_POINTEE`
> Kconfig (automatic) option is always true.
> 
> Thus remove the option and simplify the code.
> 
> In particular, this includes removing our use of the predecessor unstable
> features we used with Rust < 1.84.0 (`coerce_unsized`, `dispatch_from_dyn`
> and `unsize`).
> 
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  init/Kconfig              |  3 ---
>  rust/kernel/alloc/kbox.rs | 29 ++---------------------------
>  rust/kernel/lib.rs        |  8 +-------
>  rust/kernel/list/arc.rs   | 22 +---------------------
>  rust/kernel/sync/arc.rs   | 21 ++-------------------
>  5 files changed, 6 insertions(+), 77 deletions(-)

Re: [PATCH 06/33] rust: kbuild: remove skipping of `-Wrustdoc::unescaped_backticks`

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> 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]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  rust/Makefile | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)

Re: [PATCH 07/33] rust: kbuild: remove `feature(...)`s that are now stable

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> 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.
> 
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  rust/Makefile          |  2 --
>  rust/kernel/lib.rs     | 21 ---------------------
>  scripts/Makefile.build |  6 +-----
>  3 files changed, 1 insertion(+), 28 deletions(-)

Re: [PATCH 08/33] rust: kbuild: simplify `--remap-path-prefix` workaround

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> With the minimum version bump in place, `rustdoc` now always recognizes
> the `--remap-path-prefix` flag.
>
> In addition, the Internal Compiler Error that the comment mentions [1]
> was fixed in Rust 1.87.0 [2], so we still need to skip the flag for
> the normal `rustdoc` case, but not for `--test` since the ICE does not
> reproduce there -- please see commit 2c8725c1dca3 ("rust: kbuild: skip
> `--remap-path-prefix` for `rustdoc`").
>
> Thus update the comment and remove the skipping of the flag for the
> `--test` case.
>
> Note that commit dda135077ecc ("rust: build: remap path to avoid
> absolute path") re-landed the `--remap-path-prefix` flag (together with
> `--remap-path-scope`), so we keep the workaround, i.e. an alternative
> could have been to simply delete the skip entirely, but since we still
> have it and it will be needed when this gets merged, let's keep it.

I'm not sure that I parse this. You do remove the filter-out completely below?

>
> Link: https://github.com/rust-lang/rust/issues/138520 [1]
> Link: https://github.com/rust-lang/rust/pull/138556 [2]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
> ---
>  rust/Makefile | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/rust/Makefile b/rust/Makefile
> index 193cf06eea64..708530ee3613 100644
> --- a/rust/Makefile
> +++ b/rust/Makefile
> @@ -142,10 +142,9 @@ rustdoc_modifiers_workaround := $(if $(call rustc-min-version,108800),-Cunsafe-a
>  # Similarly, for doctests (https://github.com/rust-lang/rust/issues/146465).
>  doctests_modifiers_workaround := $(rustdoc_modifiers_workaround)$(if $(call rustc-min-version,109100),$(comma)sanitizer)
>  
> -# `rustc` recognizes `--remap-path-prefix` since 1.26.0, but `rustdoc` only
> -# since Rust 1.81.0. Moreover, `rustdoc` ICEs on out-of-tree builds since Rust
> -# 1.82.0 (https://github.com/rust-lang/rust/issues/138520). Thus workaround both
> -# issues skipping the flag. The former also applies to `RUSTDOC TK`.
> +# `rustdoc` ICEs on out-of-tree builds in Rust < 1.87.0
> +# (https://github.com/rust-lang/rust/issues/138520). Thus workaround the
> +# issue skipping the flag.
>  quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $<
>        cmd_rustdoc = \
>  	OBJTREE=$(abspath $(objtree)) \
> @@ -333,7 +332,7 @@ quiet_cmd_rustdoc_test_kernel = RUSTDOC TK $<
>  	rm -rf $(objtree)/$(obj)/test/doctests/kernel; \
>  	mkdir -p $(objtree)/$(obj)/test/doctests/kernel; \
>  	OBJTREE=$(abspath $(objtree)) \
> -	$(RUSTDOC) --test $(filter-out --remap-path-prefix=%,$(rust_flags)) \

Looks like this is going to conflict with rust-fixes (which adds the
--remap-path-scope). Perhaps worth doing a back merge?

Best,
Gary


> +	$(RUSTDOC) --test $(rust_flags) \
>  		-L$(objtree)/$(obj) --extern ffi --extern pin_init \
>  		--extern kernel --extern build_error --extern macros \
>  		--extern bindings --extern uapi \

Re: [PATCH 09/33] rust: kbuild: make `--remap-path-prefix` workaround conditional

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> The Internal Compiler Error that the comment mentions [1] was fixed in
> Rust 1.87.0 [2]. And, for other workarounds, we plan on limiting where
> we apply them [3].
>
> Thus limit the ICE one too.
>
> This will help to make sure the workaround is not needed anymore on
> newer versions.
>
> Link: https://github.com/rust-lang/rust/issues/138520 [1]
> Link: https://github.com/rust-lang/rust/pull/138556 [2]
> Link: https://lore.kernel.org/rust-for-linux/20260205131815.2943152-2-mlksvender@gmail.com/ [3]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
> ---
>  rust/Makefile | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/rust/Makefile b/rust/Makefile
> index 708530ee3613..163d2258e93f 100644
> --- a/rust/Makefile
> +++ b/rust/Makefile
> @@ -145,10 +145,12 @@ doctests_modifiers_workaround := $(rustdoc_modifiers_workaround)$(if $(call rust
>  # `rustdoc` ICEs on out-of-tree builds in Rust < 1.87.0
>  # (https://github.com/rust-lang/rust/issues/138520). Thus workaround the
>  # issue skipping the flag.
> +rustdoc_remap_workaround := $(if $(call rustc-min-version,108700),,--remap-path-prefix=%)

Okay, I see what the comments mean now. Perhaps squash this to the previous
commit?

Best,
Gary

> +
>  quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $<
>        cmd_rustdoc = \
>  	OBJTREE=$(abspath $(objtree)) \
> -	$(RUSTDOC) $(filter-out $(skip_flags) --remap-path-prefix=%,$(if $(rustdoc_host),$(rust_common_flags),$(rust_flags))) \
> +	$(RUSTDOC) $(filter-out $(skip_flags) $(rustdoc_remap_workaround),$(if $(rustdoc_host),$(rust_common_flags),$(rust_flags))) \
>  		$(rustc_target_flags) -L$(objtree)/$(obj) \
>  		-Zunstable-options --generate-link-to-definition \
>  		--output $(rustdoc_output) \

Re: [PATCH 10/33] rust: transmute: simplify code with Rust 1.80.0 `split_at_*checked()`

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> `feature(split_at_checked)` [1] has been stabilized in Rust 1.80.0 [2],
> which is beyond our new minimum Rust version (Rust 1.85.0).
> 
> Thus simplify the code using `split_at_*checked()`.
> 
> Link: https://github.com/rust-lang/rust/issues/119128 [1]
> Link: https://github.com/rust-lang/rust/pull/124678 [2]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  rust/kernel/transmute.rs | 33 ++++++---------------------------
>  1 file changed, 6 insertions(+), 27 deletions(-)

Re: [PATCH 11/33] rust: alloc: simplify with `NonNull::add()` now that it is stable

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> Currently we need to go through raw pointers and then re-create the
> `NonNull` from the result of offsetting the raw pointer.
> 
> Thus, now that we bump the Rust minimum version, simplify using
> `NonNull::add()` and clean the TODO note.
> 
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  rust/kernel/alloc/allocator/iter.rs | 8 +-------
>  1 file changed, 1 insertion(+), 7 deletions(-)

Re: [PATCH 12/33] rust: macros: update `extract_if` MSRV TODO comment

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> `feature(extract_if)` was stabilized in Rust 1.87.0 [1].
>
> Thus update the comment to reflect that.
>
> Alternatively, we could use it unstably already.
>
> Link: https://github.com/rust-lang/rust/pull/137109 [1]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
> ---
>  rust/macros/kunit.rs | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/rust/macros/kunit.rs b/rust/macros/kunit.rs
> index 6be880d634e2..6f6d746b8dbb 100644
> --- a/rust/macros/kunit.rs
> +++ b/rust/macros/kunit.rs
> @@ -87,7 +87,7 @@ pub(crate) fn kunit_tests(test_suite: Ident, mut module: ItemMod) -> Result<Toke
>              continue;
>          };
>  
> -        // TODO: Replace below with `extract_if` when MSRV is bumped above 1.85.
> +        // TODO: Replace with `extract_if` when MSRV is >= 1.87.0.
>          let before_len = f.attrs.len();
>          f.attrs.retain(|attr| !attr.path().is_ident("test"));
>          if f.attrs.len() == before_len {

When I write the comment the intention is to enable the unstable feature and
switch.

Best,
Gary

diff --git a/rust/macros/kunit.rs b/rust/macros/kunit.rs
index 6be880d634e2..ae20ed6768f1 100644
--- a/rust/macros/kunit.rs
+++ b/rust/macros/kunit.rs
@@ -87,10 +87,11 @@ pub(crate) fn kunit_tests(test_suite: Ident, mut module: ItemMod) -> Result<Toke
             continue;
         };
 
-        // TODO: Replace below with `extract_if` when MSRV is bumped above 1.85.
-        let before_len = f.attrs.len();
-        f.attrs.retain(|attr| !attr.path().is_ident("test"));
-        if f.attrs.len() == before_len {
+        if f.attrs
+            .extract_if(.., |attr| attr.path().is_ident("test"))
+            .count()
+            == 0
+        {
             processed_items.push(Item::Fn(f));
             continue;
         }
diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
index 0c36194d9971..2cfd59e0f9e7 100644
--- a/rust/macros/lib.rs
+++ b/rust/macros/lib.rs
@@ -6,6 +6,9 @@
 // and thus add a dependency on `include/config/RUSTC_VERSION_TEXT`, which is
 // touched by Kconfig when the version string from the compiler changes.
 
+// Stable since Rust 1.87.0.
+#![feature(extract_if)]
+//
 // Stable since Rust 1.88.0 under a different name, `proc_macro_span_file`,
 // which was added in Rust 1.88.0. This is why `cfg_attr` is used here, i.e.
 // to avoid depending on the full `proc_macro_span` on Rust >= 1.88.0.

Re: [PATCH 13/33] rust: block: update `const_refs_to_static` MSRV TODO comment

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> `feature(const_refs_to_static)` was stabilized in Rust 1.83.0 [1].
> 
> Thus update the comment to reflect that.
> 
> Link: https://github.com/rust-lang/rust/pull/129759 [1]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  rust/kernel/block/mq/gen_disk.rs | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)

Re: [PATCH 14/33] rust: bump `bindgen` minimum supported version to 0.71.1 (Debian Trixie)

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> As proposed in the past in e.g. LPC 2025 and the Maintainers Summit [1],
> we are going to follow Debian Stable's `bindgen` versions as our minimum
> supported version.
> 
> Debian Trixie was released with `bindgen` 0.71.1, which it still uses
> to this day [2].
> 
> Debian Trixie's release happened on 2025-08-09 [3], 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 version.
> 
> Then, in later commits, clean up most of the workarounds and other bits
> that this upgrade of the minimum allows us.
> 
> Ubuntu 25.10 also has a recent enough `bindgen` [4] (even the already
> unsupported Ubuntu 25.04 had it), and they also provide versioned packages
> with `bindgen` 0.71.1 back to Ubuntu 24.04 LTS [5].
> 
> Link: https://lwn.net/Articles/1050174/ [1]
> Link: https://packages.debian.org/trixie/bindgen [2]
> Link: https://www.debian.org/releases/trixie/ [3]
> Link: https://packages.ubuntu.com/search?suite=all&searchon=names&keywords=bindgen [4]
> Link: https://launchpad.net/ubuntu/+source/rust-bindgen-0.71 [5]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  Documentation/process/changes.rst | 2 +-
>  scripts/min-tool-version.sh       | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)

Re: [PATCH 01/33] rust: bump Rust minimum supported version to 1.85.0 (Debian Trixie)

[Benno Lossin]

On Wed Apr 1, 2026 at 1:45 PM CEST, Miguel Ojeda wrote:
> 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's release happened on 2025-08-09 [4], 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 version.
>
> Then, in later commits, clean up most of the workarounds and other bits
> that this upgrade of the minimum allows us.
>
> pin-init was left as-is since the patches come from upstream. And the
> vendored crates are unmodified, since we do not want to change those.
>
> Note that the minimum LLVM major version for Rust 1.85.0 is LLVM 18 (the
> Rust upstream binaries use LLVM 19.1.7), thus e.g. `RUSTC_LLVM_VERSION`
> tests can also be updated, but there are no suitable ones to simplify.
>
> Ubuntu 25.10 also has a recent enough Rust toolchain [5], and they also
> provide versioned packages with a Rust 1.85.1 toolchain even back to
> Ubuntu 22.04 LTS [6].
>
> 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://www.debian.org/releases/trixie/ [4]
> Link: https://packages.ubuntu.com/search?suite=all&searchon=names&keywords=rustc [5]
> Link: https://launchpad.net/ubuntu/+source/rustc-1.85 [6]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Very happy to see this!

Acked-by: Benno Lossin <lossin@kernel.org>

Cheers,
Benno

> ---
>  Documentation/process/changes.rst | 2 +-
>  scripts/min-tool-version.sh       | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)

Re: [PATCH 15/33] rust: rust_is_available: remove warning for 0.66.[01] buggy versions

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> It is not possible anymore to fall into the issue that this warning was
> alerting about given the `bindgen` version bump.
>
> Thus simplify by removing the machinery behind it, including tests.

The scripts/rust_is_available.sh change looks correct to me, although I couldn't
get scripts/rust_is_available_test.py to run on NixOS. 

Looks like it filtered out PATH but uses /usr/bin/env to find python binary? For
obvious reasons that will only work if python is located /usr/bin/python.

Best,
Gary

>
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
> ---
>  scripts/rust_is_available.sh             | 13 ------------
>  scripts/rust_is_available_bindgen_0_66.h |  2 --
>  scripts/rust_is_available_test.py        | 26 +++---------------------
>  3 files changed, 3 insertions(+), 38 deletions(-)
>  delete mode 100644 scripts/rust_is_available_bindgen_0_66.h
>
> diff --git a/scripts/rust_is_available.sh b/scripts/rust_is_available.sh
> index d2323de0692c..77896e31dab5 100755
> --- a/scripts/rust_is_available.sh
> +++ b/scripts/rust_is_available.sh
> @@ -163,19 +163,6 @@ if [ "$rust_bindings_generator_cversion" -lt "$rust_bindings_generator_min_cvers
>  	echo >&2 "***"
>  	exit 1
>  fi
> -if [ "$rust_bindings_generator_cversion" -eq 6600 ] ||
> -	[ "$rust_bindings_generator_cversion" -eq 6601 ]; then
> -	# Distributions may have patched the issue (e.g. Debian did).
> -	if ! "$BINDGEN" $(dirname $0)/rust_is_available_bindgen_0_66.h >/dev/null; then
> -		echo >&2 "***"
> -		echo >&2 "*** Rust bindings generator '$BINDGEN' versions 0.66.0 and 0.66.1 may not"
> -		echo >&2 "*** work due to a bug (https://github.com/rust-lang/rust-bindgen/pull/2567),"
> -		echo >&2 "*** unless patched (like Debian's)."
> -		echo >&2 "***   Your version:     $rust_bindings_generator_version"
> -		echo >&2 "***"
> -		warning=1
> -	fi
> -fi
>  
>  # Check that the `libclang` used by the Rust bindings generator is suitable.
>  #
> diff --git a/scripts/rust_is_available_bindgen_0_66.h b/scripts/rust_is_available_bindgen_0_66.h
> deleted file mode 100644
> index c0431293421c..000000000000
> --- a/scripts/rust_is_available_bindgen_0_66.h
> +++ /dev/null
> @@ -1,2 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -#define A "\0"
> diff --git a/scripts/rust_is_available_test.py b/scripts/rust_is_available_test.py
> index 4fcc319dea84..b66fa5933844 100755
> --- a/scripts/rust_is_available_test.py
> +++ b/scripts/rust_is_available_test.py
> @@ -54,17 +54,12 @@ else:
>  """)
>  
>      @classmethod
> -    def generate_bindgen(cls, version_stdout, libclang_stderr, version_0_66_patched=False, libclang_concat_patched=False):
> +    def generate_bindgen(cls, version_stdout, libclang_stderr, libclang_concat_patched=False):
>          if libclang_stderr is None:
>              libclang_case = f"raise SystemExit({cls.bindgen_default_bindgen_libclang_failure_exit_code})"
>          else:
>              libclang_case = f"print({repr(libclang_stderr)}, file=sys.stderr)"
>  
> -        if version_0_66_patched:
> -            version_0_66_case = "pass"
> -        else:
> -            version_0_66_case = "raise SystemExit(1)"
> -
>          if libclang_concat_patched:
>              libclang_concat_case = "print('pub static mut foofoo: ::std::os::raw::c_int;')"
>          else:
> @@ -74,8 +69,6 @@ else:
>  import sys
>  if "rust_is_available_bindgen_libclang.h" in " ".join(sys.argv):
>      {libclang_case}
> -elif "rust_is_available_bindgen_0_66.h" in " ".join(sys.argv):
> -    {version_0_66_case}
>  elif "rust_is_available_bindgen_libclang_concat.h" in " ".join(sys.argv):
>      {libclang_concat_case}
>  else:
> @@ -83,8 +76,8 @@ else:
>  """)
>  
>      @classmethod
> -    def generate_bindgen_version(cls, stdout, version_0_66_patched=False):
> -        return cls.generate_bindgen(stdout, cls.bindgen_default_bindgen_libclang_stderr, version_0_66_patched)
> +    def generate_bindgen_version(cls, stdout):
> +        return cls.generate_bindgen(stdout, cls.bindgen_default_bindgen_libclang_stderr)
>  
>      @classmethod
>      def generate_bindgen_libclang_failure(cls):
> @@ -245,19 +238,6 @@ else:
>          result = self.run_script(self.Expected.FAILURE, { "BINDGEN": bindgen })
>          self.assertIn(f"Rust bindings generator '{bindgen}' is too old.", result.stderr)
>  
> -    def test_bindgen_bad_version_0_66_0_and_0_66_1(self):
> -        for version in ("0.66.0", "0.66.1"):
> -            with self.subTest(version=version):
> -                bindgen = self.generate_bindgen_version(f"bindgen {version}")
> -                result = self.run_script(self.Expected.SUCCESS_WITH_WARNINGS, { "BINDGEN": bindgen })
> -                self.assertIn(f"Rust bindings generator '{bindgen}' versions 0.66.0 and 0.66.1 may not", result.stderr)
> -
> -    def test_bindgen_bad_version_0_66_0_and_0_66_1_patched(self):
> -        for version in ("0.66.0", "0.66.1"):
> -            with self.subTest(version=version):
> -                bindgen = self.generate_bindgen_version(f"bindgen {version}", True)
> -                result = self.run_script(self.Expected.SUCCESS, { "BINDGEN": bindgen })
> -
>      def test_bindgen_libclang_failure(self):
>          bindgen = self.generate_bindgen_libclang_failure()
>          result = self.run_script(self.Expected.FAILURE, { "BINDGEN": bindgen })

Re: [PATCH 17/33] rust: kbuild: update `bindgen --rust-target` version and replace comment

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> 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.
> 
> 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.
> 
> Thus replace the comment and simply write our minimum supported Rust
> version there, which is much simpler.
> 
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  rust/Makefile | 16 ++--------------
>  1 file changed, 2 insertions(+), 14 deletions(-)

Re: [PATCH 18/33] rust: kbuild: remove "dummy parameter" workaround for `bindgen` < 0.71.1

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> Until the version bump of `bindgen`, we needed to pass a dummy parameter
> to avoid failing the `--version` call.
> 
> Thus remove it.
> 
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  init/Kconfig                 | 7 +------
>  scripts/rust_is_available.sh | 8 +-------
>  2 files changed, 2 insertions(+), 13 deletions(-)

Re: [PATCH 19/33] rust: kbuild: remove "`try` keyword" workaround for `bindgen` < 0.59.2

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> There is a workaround that has not been needed, even already after commit
> 08ab786556ff ("rust: bindgen: upgrade to 0.65.1"), but it does not hurt.
> 
> Thus remove it.
> 
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  rust/bindgen_parameters | 4 ----
>  1 file changed, 4 deletions(-)

Re: [PATCH 20/33] rust: kbuild: remove unneeded old `allow`s for generated layout tests

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> The issue that required `allow`s for `cfg(test)` code generated by
> `bindgen` for layout testing was fixed back in `bindgen` 0.60.0 [1],
> so it could have been removed even before the version bump, but it does
> not hurt.
> 
> Thus remove it now.
> 
> Link: https://github.com/rust-lang/rust-bindgen/pull/2203 [1]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  rust/bindings/lib.rs | 4 ----
>  rust/uapi/lib.rs     | 4 ----
>  2 files changed, 8 deletions(-)

Re: [PATCH 21/33] gpu: nova-core: bindings: remove unneeded `cfg_attr`

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> These were likely copied from the `bindings` and `uapi` crates, but are
> unneeded since there are no `cfg(test)`s in the bindings.
> 
> In addition, the issue that triggered the addition in those crates
> originally is also fixed in `bindgen` (please see the previous commit).
> 
> Thus remove them.
> 
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  drivers/gpu/nova-core/gsp/fw/r570_144.rs | 3 ---

I believe drivers/gpu/nova-core/gsp/fw/r570_144/bindings.rs is generated
manually and checked in to the source tree? It might be useful to actually have
the command line and bindgen version used to generate the file present
somewhere for knowing about possible compatibility issues like this one and
reproducibility..

Best,
Gary

>  1 file changed, 3 deletions(-)

Re: [PATCH 27/33] docs: rust: quick-start: remove Nix "unstable channel" note

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> Nix does not need the "unstable channel" note, since its packages are
> recent enough even in the stable channel [1][2].
> 
> Thus remove it to simplify the documentation.
> 
> Link: https://search.nixos.org/packages?channel=25.11&query=rust [1]
> Link: https://search.nixos.org/packages?channel=25.11&query=bindgen [2]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  Documentation/rust/quick-start.rst | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Re: [PATCH 28/33] docs: rust: quick-start: remove GDB/Binutils mention

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> The versions provided nowadays by even a distribution like Debian Stable
> (and Debian Old Stable) are newer than those mentioned [1].
>
> Thus remove the workaround.
>
> Note that the minimum binutils version in the kernel is still 2.30, so
> one could argue part of the note is still relevant, but it is unlikely
> a kernel developer using such an old binutils is enabling Rust on a
> modern kernel, especially when using distribution toolchains, e.g. the
> Rust minimum version is not satisfied by Debian Old Stable.

I suppose people could have been using an old LTS distro + rustup and run into
this issue. Albeit it's probably quite unlikely.

Reviewed-by: Gary Guo <gary@garyguo.net>

>
> So we are at the point where keeping the docs short and relevant for
> essentially everyone is probably the better trade-off.
>
> Link: https://packages.debian.org/search?suite=all&searchon=names&keywords=binutils [1]
> Link: https://lore.kernel.org/all/CANiq72mCpc9=2TN_zC4NeDMpFQtPXAFvyiP+gRApg2vzspPWmw@mail.gmail.com/
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
> ---
>  Documentation/rust/quick-start.rst | 9 ---------
>  1 file changed, 9 deletions(-)
>
> diff --git a/Documentation/rust/quick-start.rst b/Documentation/rust/quick-start.rst
> index 5bbe059a8fa3..a6ec3fa94d33 100644
> --- a/Documentation/rust/quick-start.rst
> +++ b/Documentation/rust/quick-start.rst
> @@ -352,12 +352,3 @@ Hacking
>  To dive deeper, take a look at the source code of the samples
>  at ``samples/rust/``, the Rust support code under ``rust/`` and
>  the ``Rust hacking`` menu under ``Kernel hacking``.
> -
> -If GDB/Binutils is used and Rust symbols are not getting demangled, the reason
> -is the toolchain does not support Rust's new v0 mangling scheme yet.
> -There are a few ways out:
> -
> -- Install a newer release (GDB >= 10.2, Binutils >= 2.36).
> -
> -- Some versions of GDB (e.g. vanilla GDB 10.1) are able to use
> -  the pre-demangled names embedded in the debug info (``CONFIG_DEBUG_INFO``).

Re: [PATCH 29/33] docs: rust: general-information: simplify Kconfig example

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> There is no need to use `def_bool y if <expr>` -- one can simply write
> `def_bool <expr>`.
> 
> In fact, the simpler form is how we actually use them in practice in
> `init/Kconfig`.
> 
> Thus simplify the example.
> 
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  Documentation/rust/general-information.rst | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Re: [PATCH 30/33] docs: rust: general-information: use real example

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> Currently the example in the documentation shows a version-based name
> for the Kconfig example:
> 
>     RUSTC_VERSION_MIN_107900
> 
> The reason behind it was to possibly avoid repetition in case several
> features used the same minimum.
> 
> However, we ended up preferring to give them a descriptive name for each
> feature added even if that could lead to some repetition. In practice,
> the repetition has not happened so far, and even if it does at some point,
> it is not a big deal.
> 
> Thus replace the example in the documentation with one of our current
> examples (after removing previous ones from the bump), to show how they
> actually look like, and in case someone `grep`s for it.
> 
> In addition, it has the advantage that it shows the `RUSTC_HAS_*`
> pattern we follow in `init/Kconfig`, similar to the C side.
> 
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  Documentation/rust/general-information.rst | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Re: [PATCH 31/33] rust: declare cfi_encoding for lru_status

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> From: Alice Ryhl <aliceryhl@google.com>
> 
> By default bindgen will convert 'enum lru_status' into a typedef for an
> integer. For the most part, an integer of the same size as the enum
> results in the correct ABI, but in the specific case of CFI, that is not
> the case. The CFI encoding is supposed to be the same as a struct called
> 'lru_status' rather than the name of the underlying native integer type.
> 
> To fix this, tell bindgen to generate a newtype and set the CFI type
> explicitly. Note that we need to set the CFI attribute explicitly as
> bindgen is using repr(transparent), which is otherwise identical to the
> inner type for ABI purposes.
> 
> This allows us to remove the page range helper C function in Binder
> without risking a CFI failure when list_lru_walk calls the provided
> function pointer.
> 
> The --with-attribute-custom-enum argument requires bindgen v0.71 or
> greater.
> 
> [ In particular, the feature was added in 0.71.0 [1][2].
> 
>   In addition, `feature(cfi_encoding)` has been available since
>   Rust 1.71.0 [3].
> 
>   Link: https://github.com/rust-lang/rust-bindgen/issues/2520 [1]
>   Link: https://github.com/rust-lang/rust-bindgen/pull/2866 [2]
>   Link: https://github.com/rust-lang/rust/pull/105452 [3]
> 
>     - Miguel ]
> 
> My testing procedure was to add this to the android17-6.18 branch and
> verify that rust_shrink_free_page is successfully called without crash,
> and verify that it does in fact crash when the cfi_encoding is set to
> other values. Note that I couldn't test this on android16-6.12 as that
> branch uses a bindgen version that is too old.
> 
> Signed-off-by: Alice Ryhl <aliceryhl@google.com>
> Link: https://patch.msgid.link/20260223-cfi-lru-status-v2-1-89c6448a63a4@google.com
> [ Rebased on top of the minimum Rust version bump series which provide
>   the required `bindgen` version. - Miguel ]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  drivers/android/binder/Makefile            |  3 +--
>  drivers/android/binder/page_range.rs       |  6 +++---
>  drivers/android/binder/page_range_helper.c | 24 ----------------------
>  drivers/android/binder/page_range_helper.h | 15 --------------
>  rust/bindgen_parameters                    |  4 ++++
>  rust/bindings/bindings_helper.h            |  1 -
>  rust/bindings/lib.rs                       |  1 +
>  rust/uapi/lib.rs                           |  1 +
>  8 files changed, 10 insertions(+), 45 deletions(-)
>  delete mode 100644 drivers/android/binder/page_range_helper.c
>  delete mode 100644 drivers/android/binder/page_range_helper.h

Re: [PATCH 32/33] rust: kbuild: support global per-version flags

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> 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`.
>
> An alternative is moving all those three down, but that would mean
> separating them from the other `KBUILD_*` variables.

I think I would prefer moving these down.

The current approach append the flags to all variables, which will cause the
following equivalence to stop holding after the flag update.

KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
			-Zallow-features= $(HOSTRUSTFLAGS)

(Per version flags doesn't go before -O anymore, it comes after HOSTRUSTFLAGS).

Best,
Gary

>
> Link: https://lore.kernel.org/rust-for-linux/CANiq72mWdFU11GcCZRchzhy0Gi1QZShvZtyRkHV2O+WA2uTdVQ@mail.gmail.com/ [1]
> Link: https://patch.msgid.link/20260307170929.153892-1-ojeda@kernel.org
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
> ---
>  Makefile | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/Makefile b/Makefile
> index 1a219bf1c771..20c8179d96ee 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -834,6 +834,14 @@ endif # CONFIG_TRACEPOINTS
>  
>  export WARN_ON_UNUSED_TRACEPOINTS
>  
> +# Per-version Rust flags. These are like `rust_common_flags`, but may
> +# depend on the Rust compiler version (e.g. using `rustc-min-version`).
> +rust_common_flags_per_version :=
> +
> +rust_common_flags += $(rust_common_flags_per_version)
> +KBUILD_HOSTRUSTFLAGS += $(rust_common_flags_per_version)
> +KBUILD_RUSTFLAGS += $(rust_common_flags_per_version)
> +
>  include $(srctree)/arch/$(SRCARCH)/Makefile
>  
>  ifdef need-config

Re: [PATCH 33/33] rust: kbuild: allow `clippy::precedence` for Rust < 1.86.0

[Gary Guo]

On Wed Apr 1, 2026 at 12:45 PM BST, Miguel Ojeda wrote:
> 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)
>        |
> 
>     warning: operator precedence can trip the unwary
>        --> drivers/gpu/nova-core/vbios.rs:511:17
>         |
>     511 | /                 u32::from(data[29]) << 24
>     512 | |                     | u32::from(data[28]) << 16
>     513 | |                     | u32::from(data[27]) << 8
>         | |______________________________________________^
>         |
>         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#precedence
>     help: consider parenthesizing your expression
>         |
>     511 ~                 u32::from(data[29]) << 24
>     512 +                     | u32::from(data[28]) << 16 | (u32::from(data[27]) << 8)
>         |
> 
>     warning: operator precedence can trip the unwary
>        --> drivers/gpu/nova-core/vbios.rs:511:17
>         |
>     511 | /                 u32::from(data[29]) << 24
>     512 | |                     | u32::from(data[28]) << 16
>         | |_______________________________________________^ help: consider parenthesizing your expression: `(u32::from(data[29]) << 24) | (u32::from(data[28]) << 16)`
>         |
>         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#precedence
> 
> 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 "false positives"
> 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]
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Link: https://lore.kernel.org/rust-for-linux/DFVDKMMA7KPC.2DN0951H3H55Y@kernel.org/
Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  Makefile | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Re: [PATCH 05/33] rust: remove `RUSTC_HAS_COERCE_POINTEE` and simplify code

[Danilo Krummrich]

On 4/1/26 1:45 PM, Miguel Ojeda wrote:
>  rust/kernel/alloc/kbox.rs | 29 ++---------------------------

Acked-by: Danilo Krummrich <dakr@kernel.org>

Re: [PATCH 02/33] rust: bump Clippy's MSRV and clean `incompatible_msrv` allows

[Danilo Krummrich]

On 4/1/26 1:45 PM, Miguel Ojeda wrote:
>  drivers/gpu/nova-core/gsp/cmdq.rs | 6 +-----

Acked-by: Danilo Krummrich <dakr@kernel.org>

Re: [PATCH 08/33] rust: kbuild: simplify `--remap-path-prefix` workaround

[Miguel Ojeda]

On Wed, Apr 1, 2026 at 3:59 PM Gary Guo <gary@garyguo.net> wrote:
>
> I'm not sure that I parse this. You do remove the filter-out completely below?

(I see you saw the other commit)

> Looks like this is going to conflict with rust-fixes (which adds the
> --remap-path-scope). Perhaps worth doing a back merge?

It would be only a couple lines conflicting, so it should be fine.

Having said that, when I was doing this, I wondered if we should even
consider keeping the workaround. In other words, locally for
`rust-next`, the "normal" commit would be to remove the workaround
entirely because there the flag doesn't exist to begin with (i.e. the
workaround should have been removed back when the revert landed).

Then, when conflict happens in linux-next, we can just keep the
addition of the flag from your commit -- the rest can say as-is, i.e.
no workaround needed, because you only enable both flags in a version
(1.95.0) where there is no need for the workaround (which was for <
1.87.0).

It is also why I added the second commit here, i.e. the "make it
conditional", because I was testing that indeed we didn't need the
workaround anymore.

So it may just simpler to do that. What I thought was that perhaps the
workaround is good even if we ourselves don't pass the flag, e.g.
someone else may be passing it. But the chances are very low,
restricted to a couple versions, and the error is obvious and at build
time anyway.

Cheers,
Miguel

Re: [PATCH 09/33] rust: kbuild: make `--remap-path-prefix` workaround conditional

[Miguel Ojeda]

On Wed, Apr 1, 2026 at 4:08 PM Gary Guo <gary@garyguo.net> wrote:
>
> Okay, I see what the comments mean now. Perhaps squash this to the previous
> commit?

This one was mostly to ensure the workaround was not needed anymore,
i.e. it is more "optional" than the other.

In fact, we may want to just not have neither of the patches, i.e. we
could just remove the workaround given the timelines of the branches
-- please see my reply on the previous one on this.

Cheers,
Miguel

Re: [PATCH 12/33] rust: macros: update `extract_if` MSRV TODO comment

[Miguel Ojeda]

On Wed, Apr 1, 2026 at 4:18 PM Gary Guo <gary@garyguo.net> wrote:
>
> When I write the comment the intention is to enable the unstable feature and
> switch.

Yeah, that is what I meant as the alternative in the commit message.

I am OK with either.

(By the way, I wondered why you mentioned 1.85 in the comment, I guess
it was supposed to be 1.86 instead originally, i.e. "above" as in >
1.86)

Cheers,
Miguel

Re: [PATCH 01/33] rust: bump Rust minimum supported version to 1.85.0 (Debian Trixie)

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:08 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> 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).
> 
> [...]

Acked-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 02/33] rust: bump Clippy's MSRV and clean `incompatible_msrv` allows

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:09 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> Following the Rust compiler bump, we can now update Clippy's MSRV we
> set in the configuration, which will improve the diagnostics it generates.
> 
> Thus do so and clean a few of the `allow`s that are not needed anymore.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 03/33] rust: simplify `RUSTC_VERSION` Kconfig conditions

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:10 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> With the Rust version bump in place, several Kconfig conditions based on
> `RUSTC_VERSION` are always true.
> 
> Thus simplify them.
> 
> The minimum supported major LLVM version by our new Rust minimum version
> is now LLVM 18, instead of LLVM 16. However, there are no possible
> cleanups for `RUSTC_LLVM_VERSION`.
> 
> [...]

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 04/33] rust: remove `RUSTC_HAS_SLICE_AS_FLATTENED` and simplify code

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:11 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> With the Rust version bump in place, the `RUSTC_HAS_SLICE_AS_FLATTENED`
> Kconfig (automatic) option is always true.
> 
> Thus remove the option and simplify the code.
> 
> In particular, this includes removing the `slice` module which contained
> the temporary slice helpers, i.e. the `AsFlattened` extension trait and
> its `impl`s.
> 
> [...]

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 05/33] rust: remove `RUSTC_HAS_COERCE_POINTEE` and simplify code

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:12 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> With the Rust version bump in place, the `RUSTC_HAS_COERCE_POINTEE`
> Kconfig (automatic) option is always true.
> 
> Thus remove the option and simplify the code.
> 
> In particular, this includes removing our use of the predecessor unstable
> features we used with Rust < 1.84.0 (`coerce_unsized`, `dispatch_from_dyn`
> and `unsize`).
> 
> [...]

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 06/33] rust: kbuild: remove skipping of `-Wrustdoc::unescaped_backticks`

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:13 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> 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.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 07/33] rust: kbuild: remove `feature(...)`s that are now stable

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:14 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> 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>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 08/33] rust: kbuild: simplify `--remap-path-prefix` workaround

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:15 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:

Does this simplify the workaround, or just remove one instance of it?

> [...]
> 
> Note that commit dda135077ecc ("rust: build: remap path to avoid
> absolute path") re-landed the `--remap-path-prefix` flag (together with
> `--remap-path-scope`), so we keep the workaround, i.e. an alternative
> could have been to simply delete the skip entirely, but since we still
> have it and it will be needed when this gets merged, let's keep it.

The use of "re-landed" is confusing without a mention of commit
8cf5b3f83614 ("Revert "kbuild, rust: use -fremap-path-prefix to make
paths relative""). Though this whole thing might be clearer without a
mention of that history; the important part is that there's no
conditional use of `--remap-path-scope` in the base commit but there
will be when dda135077ecc is merged (the use of "this" in "this gets
merged" is also ambiguous).

>
>
> diff --git a/rust/Makefile b/rust/Makefile
> index 193cf06eea64..708530ee3613 100644
> --- a/rust/Makefile
> +++ b/rust/Makefile
> @@ -142,10 +142,9 @@ rustdoc_modifiers_workaround := $(if $(call rustc-min-version,108800),-Cunsafe-a
>  # Similarly, for doctests (https://github.com/rust-lang/rust/issues/146465).
>  doctests_modifiers_workaround := $(rustdoc_modifiers_workaround)$(if $(call rustc-min-version,109100),$(comma)sanitizer)
>  
> -# `rustc` recognizes `--remap-path-prefix` since 1.26.0, but `rustdoc` only
> -# since Rust 1.81.0. Moreover, `rustdoc` ICEs on out-of-tree builds since Rust
> -# 1.82.0 (https://github.com/rust-lang/rust/issues/138520). Thus workaround both
> -# issues skipping the flag. The former also applies to `RUSTDOC TK`.
> +# `rustdoc` ICEs on out-of-tree builds in Rust < 1.87.0
> +# (https://github.com/rust-lang/rust/issues/138520). Thus workaround the
> +# issue skipping the flag.

_by_ skipping the flag? this is preexisting, though.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 09/33] rust: kbuild: make `--remap-path-prefix` workaround conditional

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:16 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> The Internal Compiler Error that the comment mentions [1] was fixed in
> Rust 1.87.0 [2]. And, for other workarounds, we plan on limiting where
> we apply them [3].
> 
> Thus limit the ICE one too.
> 
> This will help to make sure the workaround is not needed anymore on
> newer versions.
> 
> [...]

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 10/33] rust: transmute: simplify code with Rust 1.80.0 `split_at_*checked()`

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:17 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> `feature(split_at_checked)` [1] has been stabilized in Rust 1.80.0 [2],
> which is beyond our new minimum Rust version (Rust 1.85.0).

"beyond" is probably not the right word here?

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 11/33] rust: alloc: simplify with `NonNull::add()` now that it is stable

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:18 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> Currently we need to go through raw pointers and then re-create the
> `NonNull` from the result of offsetting the raw pointer.
> 
> Thus, now that we bump the Rust minimum version, simplify using
> `NonNull::add()` and clean the TODO note.

This description is inconsistent with the previous one which had
citations for both the feature (function in this case) and the feature
in which it became stable (available in this case). I don't prefer
either style in particular, just that things are consistent.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 12/33] rust: macros: update `extract_if` MSRV TODO comment

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:19 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> `feature(extract_if)` was stabilized in Rust 1.87.0 [1].
> 
> Thus update the comment to reflect that.
> 
> Alternatively, we could use it unstably already.

Perhaps the TODO could mention this alternative. Would probably make a
good first issue.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 13/33] rust: block: update `const_refs_to_static` MSRV TODO comment

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:20 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> diff --git a/rust/kernel/block/mq/gen_disk.rs b/rust/kernel/block/mq/gen_disk.rs
> index c8b0ecb17082..912cb805caf5 100644
> --- a/rust/kernel/block/mq/gen_disk.rs
> +++ b/rust/kernel/block/mq/gen_disk.rs
> @@ -140,9 +140,7 @@ pub fn build<T: Operations>(
>              devnode: None,
>              alternative_gpt_sector: None,
>              get_unique_id: None,
> -            // TODO: Set to THIS_MODULE. Waiting for const_refs_to_static feature to
> -            // be merged (unstable in rustc 1.78 which is staged for linux 6.10)
> -            // <https://github.com/rust-lang/rust/issues/119618>
> +            // TODO: Set to `THIS_MODULE`.

Good first issue?

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 14/33] rust: bump `bindgen` minimum supported version to 0.71.1 (Debian Trixie)

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:21 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> As proposed in the past in e.g. LPC 2025 and the Maintainers Summit [1],
> we are going to follow Debian Stable's `bindgen` versions as our minimum
> supported version.
> 
> Debian Trixie was released with `bindgen` 0.71.1, which it still uses
> to this day [2].
> 
> [...]

Acked-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 15/33] rust: rust_is_available: remove warning for 0.66.[01] buggy versions

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:22 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> It is not possible anymore to fall into the issue that this warning was
> alerting about given the `bindgen` version bump.
> 
> Thus simplify by removing the machinery behind it, including tests.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 16/33] rust: rust_is_available: remove warning for < 0.69.5 && libclang >= 19.1

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:23 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> It is not possible anymore to fall into the issue that this warning was
> alerting about given the `bindgen` version bump.
> 
> Thus simplify by removing the machinery behind it, including tests.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 17/33] rust: kbuild: update `bindgen --rust-target` version and replace comment

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:24 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> 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.
> 
> 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.

Some citations pointing to the upstream changes would be good.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 18/33] rust: kbuild: remove "dummy parameter" workaround for `bindgen` < 0.71.1

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:25 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> Until the version bump of `bindgen`, we needed to pass a dummy parameter
> to avoid failing the `--version` call.
> 
> Thus remove it.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 19/33] rust: kbuild: remove "`try` keyword" workaround for `bindgen` < 0.59.2

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:26 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> There is a workaround that has not been needed, even already after commit
> 08ab786556ff ("rust: bindgen: upgrade to 0.65.1"), but it does not hurt.
> 
> Thus remove it.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 20/33] rust: kbuild: remove unneeded old `allow`s for generated layout tests

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:27 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> The issue that required `allow`s for `cfg(test)` code generated by
> `bindgen` for layout testing was fixed back in `bindgen` 0.60.0 [1],
> so it could have been removed even before the version bump, but it does
> not hurt.

How about ordering this, the previous patch, and the next patch ahead of
the version bump to avoid the need to mention it here?

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 21/33] gpu: nova-core: bindings: remove unneeded `cfg_attr`

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:28 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> These were likely copied from the `bindings` and `uapi` crates, but are
> unneeded since there are no `cfg(test)`s in the bindings.
> 
> In addition, the issue that triggered the addition in those crates
> originally is also fixed in `bindgen` (please see the previous commit).
> 
> Thus remove them.
> 
> [...]

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 22/33] docs: rust: quick-start: openSUSE provides `rust-src` package nowadays

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:29 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> Both openSUSE Tumbleweed and Slowroll provide the `rust-src` package
> nowadays [1].
> 
> Thus remove the version-specific one from the Quick Start guide.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 23/33] docs: rust: quick-start: update Ubuntu versioned packages

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:30 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> Now that the minimum supported Rust version is bumped, bump the versioned
> Rust packages [1][2][3][4] to that version for Ubuntu in the Quick
> Start guide.
> 
> In addition, add "may" to the `RUST_LIB_SRC` line since it does not look
> like it is needed from a quick test in a Ubuntu 24.04 LTS container.

RUST_LIB_SRC is also mentioned in the nix section, do you know if it is
still needed there?

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 24/33] docs: rust: quick-start: update minimum Ubuntu version

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:31 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> Ubuntu 25.04 is out of support [1], and Ubuntu 25.10 is the latest
> supported one.
> 
> Moreover, Ubuntu 25.10 is the first that provides a recent enough Rust
> given the minimum bump -- they provide 1.85.1 [2].
> 
> Thus update it.
> 
> [...]

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 25/33] docs: rust: quick-start: add Ubuntu 26.04 LTS and remove subsection title

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:32 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> Ubuntu 26.04 LTS (Resolute Raccoon) is scheduled to be released in a few
> weeks [1], and it has a recent enough Rust toolchain, just like Ubuntu
> 25.10 has [2][3].
> 
> We could update the title and the paragraph, but to simplify and to
> make it more consistent with the other distributions' sections, let's
> instead just remove that title. It will also reduce the differences
> later on to keep it updated. Eventually, when we remove the remaining
> subsection for older LTSs, Ubuntu should be a small section like the
> other distributions.
> 
> [...]

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 26/33] docs: rust: quick-start: remove Gentoo "testing" note

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:33 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> Gentoo does not need the "testing" note, since its packages are recent
> enough even in the stable branch [1][2].
> 
> Thus remove it to simplify the documentation.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 27/33] docs: rust: quick-start: remove Nix "unstable channel" note

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:34 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> Nix does not need the "unstable channel" note, since its packages are
> recent enough even in the stable channel [1][2].
> 
> Thus remove it to simplify the documentation.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 28/33] docs: rust: quick-start: remove GDB/Binutils mention

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:35 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> The versions provided nowadays by even a distribution like Debian Stable
> (and Debian Old Stable) are newer than those mentioned [1].
> 
> Thus remove the workaround.
> 
> Note that the minimum binutils version in the kernel is still 2.30, so
> one could argue part of the note is still relevant, but it is unlikely
> a kernel developer using such an old binutils is enabling Rust on a
> modern kernel, especially when using distribution toolchains, e.g. the
> Rust minimum version is not satisfied by Debian Old Stable.
> 
> [...]

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 29/33] docs: rust: general-information: simplify Kconfig example

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:36 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> There is no need to use `def_bool y if <expr>` -- one can simply write
> `def_bool <expr>`.
> 
> In fact, the simpler form is how we actually use them in practice in
> `init/Kconfig`.
> 
> Thus simplify the example.
> 
> [...]

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 30/33] docs: rust: general-information: use real example

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:37 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> Currently the example in the documentation shows a version-based name
> for the Kconfig example:
> 
>     RUSTC_VERSION_MIN_107900
> 
> The reason behind it was to possibly avoid repetition in case several
> features used the same minimum.
> 
> [...]

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 32/33] rust: kbuild: support global per-version flags

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:39 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> [...]
> 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`.
> 
> An alternative is moving all those three down, but that would mean
> separating them from the other `KBUILD_*` variables.

My prefernece is avoiding duplication over grouping, but either choice
should be justified by a code comment that acknowledges the
duplication/inconsisntecy.

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 33/33] rust: kbuild: allow `clippy::precedence` for Rust < 1.86.0

[Tamir Duberstein]

On Wed, 01 Apr 2026 13:45:40 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
> 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].

Might be good to retain some of this in a code comment.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>

-- 
Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 13/33] rust: block: update `const_refs_to_static` MSRV TODO comment

[Gary Guo]

On Wed Apr 1, 2026 at 11:59 PM BST, Tamir Duberstein wrote:
> On Wed, 01 Apr 2026 13:45:20 +0200, Miguel Ojeda <ojeda@kernel.org> wrote:
>> diff --git a/rust/kernel/block/mq/gen_disk.rs b/rust/kernel/block/mq/gen_disk.rs
>> index c8b0ecb17082..912cb805caf5 100644
>> --- a/rust/kernel/block/mq/gen_disk.rs
>> +++ b/rust/kernel/block/mq/gen_disk.rs
>> @@ -140,9 +140,7 @@ pub fn build<T: Operations>(
>>              devnode: None,
>>              alternative_gpt_sector: None,
>>              get_unique_id: None,
>> -            // TODO: Set to THIS_MODULE. Waiting for const_refs_to_static feature to
>> -            // be merged (unstable in rustc 1.78 which is staged for linux 6.10)
>> -            // <https://github.com/rust-lang/rust/issues/119618>
>> +            // TODO: Set to `THIS_MODULE`.
>
> Good first issue?

It's actually quite tricky. There're already attempts on the list, although I'm
not very happy with the solution.

The tricky part is that `THIS_MODULE` needs to be supplied by the leaf module,
it cannot be constructed inside the kernel crate.

Best,
Gary

>
> Reviewed-by: Tamir Duberstein <tamird@kernel.org>

Re: [PATCH 15/33] rust: rust_is_available: remove warning for 0.66.[01] buggy versions

[Miguel Ojeda]

On Wed, Apr 1, 2026 at 4:58 PM Gary Guo <gary@garyguo.net> wrote:
>
> The scripts/rust_is_available.sh change looks correct to me, although I couldn't
> get scripts/rust_is_available_test.py to run on NixOS.
>
> Looks like it filtered out PATH but uses /usr/bin/env to find python binary? For
> obvious reasons that will only work if python is located /usr/bin/python.

Yeah, the script has some assumptions on it (e.g. it also assumes
`dash` behavior vs. `bash` in a couple tests which I should relax
too). Happy to change that.

Thanks for testing it :)

Cheers,
Miguel

Re: [PATCH 10/33] rust: transmute: simplify code with Rust 1.80.0 `split_at_*checked()`

[Miguel Ojeda]

On Thu, Apr 2, 2026 at 1:00 AM Tamir Duberstein <tamird@kernel.org> wrote:
>
> "beyond" is probably not the right word here?

I think you are right -- reworded.

Thanks!

Cheers,
Miguel

Re: [PATCH 11/33] rust: alloc: simplify with `NonNull::add()` now that it is stable

[Miguel Ojeda]

On Thu, Apr 2, 2026 at 1:00 AM Tamir Duberstein <tamird@kernel.org> wrote:
>
> This description is inconsistent with the previous one which had
> citations for both the feature (function in this case) and the feature
> in which it became stable (available in this case). I don't prefer
> either style in particular, just that things are consistent.

Sure, I added a couple references. I think it is good to be consistent
(well, at least within a patch series, but I wouldn't say no to more
information even if it is inconsistent sometimes, especially across
different patch series, since everyone writes messages a bit
differently...).

Cheers,
Miguel

Re: [PATCH 17/33] rust: kbuild: update `bindgen --rust-target` version and replace comment

[Miguel Ojeda]

On Thu, Apr 2, 2026 at 1:00 AM Tamir Duberstein <tamird@kernel.org> wrote:
>
> Some citations pointing to the upstream changes would be good.

I added a couple links as usual, plus a reference to commit
7a5f93ea5862 ("rust: kbuild: set `bindgen`'s Rust target version")
that has most of the details.

[ The comment already mentioned the version, and the commit that added
that message has the details, but I agree it is a good idea to add
some references. ]

Cheers,
Miguel

Re: [PATCH 20/33] rust: kbuild: remove unneeded old `allow`s for generated layout tests

[Miguel Ojeda]

On Thu, Apr 2, 2026 at 1:01 AM Tamir Duberstein <tamird@kernel.org> wrote:
>
> How about ordering this, the previous patch, and the next patch ahead of
> the version bump to avoid the need to mention it here?

That is reasonable, yeah.

Cheers,
Miguel

Re: [PATCH 23/33] docs: rust: quick-start: update Ubuntu versioned packages

[Miguel Ojeda]

On Thu, Apr 2, 2026 at 1:01 AM Tamir Duberstein <tamird@kernel.org> wrote:
>
> RUST_LIB_SRC is also mentioned in the nix section, do you know if it is
> still needed there?

Yeah, that would be nice to know.

I tried on my own, and it does seem still required (at least with
those packages mentioned in the example). But perhaps a Nix user knows
of a better way to do it, anyway.

So I kept it.

By the way, I think it would be nice to have a "standard",
well-maintained `shell.nix` (or a flake or whatever is best nowadays)
in the kernel tree somewhere, i.e. one that is known to work, that
covers most tooling used in the kernel, etc.

Cheers,
Miguel

Re: [PATCH 32/33] rust: kbuild: support global per-version flags

[Miguel Ojeda]

On Thu, Apr 2, 2026 at 12:28 AM Gary Guo <gary@garyguo.net> wrote:
>
> I think I would prefer moving these down.
>
> The current approach append the flags to all variables, which will cause the
> following equivalence to stop holding after the flag update.
>
> KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
>                         -Zallow-features= $(HOSTRUSTFLAGS)
>
> (Per version flags doesn't go before -O anymore, it comes after HOSTRUSTFLAGS).

[ For context for others, Sashiko reported the same and we also talked
about it in a Rust for Linux call. ]

I have been thinking about this, and about potential other ways to
achieve the same thing. I think the best at the moment is to move just
the `$(HOSTRUSTFLAGS)` below, but not the rest.

The reason is that it is closer to what we do with other user (kernel)
flags (e.g. arch flags come after the general ones). But I am
wondering if we should/could set all the user variables later in the
`Makefile` in general `HOST*FLAGS` later in the `Makefile`.

In fact, there is already a limitation with the host flags: `-Werror`,
i.e. that one gets appended later, and so users cannot override it.

This may be considered a bug, because commit 7ded7d37e5f5
("scripts/Makefile.extrawarn: Respect CONFIG_WERROR / W=e for
hostprogs") says:

    While it is
    possible to avoid this behavior by passing HOSTCFLAGS=-w or
    HOSTCFLAGS=-Wno-error, it may not be the most intuitive for regular
    users not intimately familiar with Kbuild.

But passing `HOSTCFLAGS=-Wno-error` doesn't work, since it comes
earlier (`-w` does work, but because it turns off everything).

I am also a bit confused with:

    While this means there is a small portion of
    the build that does not have -Werror enabled (namely scripts/kconfig/*
    and scripts/basic/fixdep)

because it gets enabled in the build (I think it is referring to other
targets like the config ones).

Anyway, for now I moved the expansion of `HOSTRUSTFLAGS` in v2. If
Kbuild (Nathan, Nicolas) think it is a good idea to do one of the
bigger changes (e.g. for more `HOST*` flags, appending it even later),
then we can do it afterwards.

Cheers,
Miguel

Re: [PATCH 23/33] docs: rust: quick-start: update Ubuntu versioned packages

[Gary Guo]

On Sun Apr 5, 2026 at 8:35 PM BST, Miguel Ojeda wrote:
> On Thu, Apr 2, 2026 at 1:01 AM Tamir Duberstein <tamird@kernel.org> wrote:
>>
>> RUST_LIB_SRC is also mentioned in the nix section, do you know if it is
>> still needed there?
>
> Yeah, that would be nice to know.

It's still required. It's used here:
https://github.com/NixOS/nixpkgs/blob/acf7ae578589bb8bdd6f9273141d7053fed84bed/pkgs/os-specific/linux/kernel/generic.nix#L186

>
> I tried on my own, and it does seem still required (at least with
> those packages mentioned in the example). But perhaps a Nix user knows
> of a better way to do it, anyway.
>
> So I kept it.
>
> By the way, I think it would be nice to have a "standard",
> well-maintained `shell.nix` (or a flake or whatever is best nowadays)
> in the kernel tree somewhere, i.e. one that is known to work, that
> covers most tooling used in the kernel, etc.
>
> Cheers,
> Miguel

I have my dev shell here in case it helps:
https://github.com/nbdd0121/nix-collection/blob/trunk/dev/linux.nix

It makes use of oxalica's rust-overlay. It can be used with shell.nix by a
fetchTarball, but for obvious reasons you want that to be pinned and not be
fetching latest version everytime.

Flake is good for pinning, but using flake is a two-edged sword -- it both gives
you superb reproducibility so years down the line you can still build an old
environment (assuming the source tarballs used are still available or NixOS
cache server still has a copy).

But it also means that it can be outdated. So people (myself included) usually
combine pinning + regular updating by having flake.lock routinely updated.
I'm not sure that really fits well inside kernel.

If we don't use anything outside nixpkgs though, we can use "channel" feature of
imperative nix which says `import <nixpkgs>` will import user's local nixpkgs
version. A shell.nix using only that should work, but it will only be able to
use latest rustc/clippy/cargo/bindgen in nixpkgs and won't be able to include
things like klint.

Perhaps having a repo in rust-for-linux GitHub org (or somewhere else in
kernel.org SCM) where we can point people to?

Best,
Gary

Re: [PATCH 32/33] rust: kbuild: support global per-version flags

[Gary Guo]

On Mon Apr 6, 2026 at 12:15 AM BST, Miguel Ojeda wrote:
> On Thu, Apr 2, 2026 at 12:28 AM Gary Guo <gary@garyguo.net> wrote:
>>
>> I think I would prefer moving these down.
>>
>> The current approach append the flags to all variables, which will cause the
>> following equivalence to stop holding after the flag update.
>>
>> KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
>>                         -Zallow-features= $(HOSTRUSTFLAGS)
>>
>> (Per version flags doesn't go before -O anymore, it comes after HOSTRUSTFLAGS).
>
> [ For context for others, Sashiko reported the same and we also talked
> about it in a Rust for Linux call. ]
>
> I have been thinking about this, and about potential other ways to
> achieve the same thing. I think the best at the moment is to move just
> the `$(HOSTRUSTFLAGS)` below, but not the rest.
>
> The reason is that it is closer to what we do with other user (kernel)
> flags (e.g. arch flags come after the general ones). But I am
> wondering if we should/could set all the user variables later in the
> `Makefile` in general `HOST*FLAGS` later in the `Makefile`.
>
> In fact, there is already a limitation with the host flags: `-Werror`,
> i.e. that one gets appended later, and so users cannot override it.

I cared a bit more about the code clarity (where appending to all variables
feel like a hack, while moving the code block is natural).

Best,
Gary

> [...]
>
> Anyway, for now I moved the expansion of `HOSTRUSTFLAGS` in v2. If
> Kbuild (Nathan, Nicolas) think it is a good idea to do one of the
> bigger changes (e.g. for more `HOST*` flags, appending it even later),
> then we can do it afterwards.
>
> Cheers,
> Miguel

Re: [PATCH 23/33] docs: rust: quick-start: update Ubuntu versioned packages

[Miguel Ojeda]

On Mon, Apr 6, 2026 at 2:06 AM Gary Guo <gary@garyguo.net> wrote:
>
> It's still required.

Thanks for confirming!

> Perhaps having a repo in rust-for-linux GitHub org (or somewhere else in
> kernel.org SCM) where we can point people to?

...and for all these details :)

I agree that it doesn't fit perfectly within the kernel, but an update
every kernel cycle or so should be fine, I think, if you think that is
enough.

Otherwise, regarding the repository, that sounds great to me -- we
already had an old https://github.com/Rust-for-Linux/nix and
https://github.com/Rust-for-Linux/nixpkgs. Not sure if Fiona (Cc'd)
wants them, but perhaps you could reuse them (otherwise we should
archive them).

Cheers,
Miguel

Re: [PATCH 33/33] rust: kbuild: allow `clippy::precedence` for Rust < 1.86.0

[Miguel Ojeda]

On Thu, Apr 2, 2026 at 1:02 AM Tamir Duberstein <tamird@kernel.org> wrote:
>
> Might be good to retain some of this in a code comment.

Bah, I missed this note among the rest, sorry (I didn't reply to the
ones where the commit went away due to the changes in v2) -- I agree
it wouldn't hurt to remember why it is there, even if it is already in
the Git log.

I will probably add it for tomorrow, especially if I have to rebase.

Thanks!

Cheers,
Miguel