From b03917e02bf9861be887a7e67c399b3b014f88be Mon Sep 17 00:00:00 2001 From: Konstantin Andrikopoulos Date: Wed, 27 Nov 2024 15:07:38 +0000 Subject: rust: add safety comment in workqueue traits Add missing safety comments for the implementation of the unsafe traits WorkItemPointer and RawWorkItem for Arc in workqueue.rs Link: https://github.com/Rust-for-Linux/linux/issues/351. Co-developed-by: Vangelis Mamalakis Signed-off-by: Vangelis Mamalakis Suggested-by: Miguel Ojeda Reviewed-by: Alice Ryhl Signed-off-by: Konstantin Andrikopoulos Signed-off-by: Tejun Heo --- rust/kernel/workqueue.rs | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) (limited to 'rust') diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs index 4d1d2062f6eb..fd3e97192ed8 100644 --- a/rust/kernel/workqueue.rs +++ b/rust/kernel/workqueue.rs @@ -519,7 +519,15 @@ impl_has_work! { impl{T} HasWork for ClosureWork { self.work } } -// SAFETY: TODO. +// SAFETY: The `__enqueue` implementation in RawWorkItem uses a `work_struct` initialized with the +// `run` method of this trait as the function pointer because: +// - `__enqueue` gets the `work_struct` from the `Work` field, using `T::raw_get_work`. +// - The only safe way to create a `Work` object is through `Work::new`. +// - `Work::new` makes sure that `T::Pointer::run` is passed to `init_work_with_key`. +// - Finally `Work` and `RawWorkItem` guarantee that the correct `Work` field +// will be used because of the ID const generic bound. This makes sure that `T::raw_get_work` +// uses the correct offset for the `Work` field, and `Work::new` picks the correct +// implementation of `WorkItemPointer` for `Arc`. unsafe impl WorkItemPointer for Arc where T: WorkItem, @@ -537,7 +545,13 @@ where } } -// SAFETY: TODO. +// SAFETY: The `work_struct` raw pointer is guaranteed to be valid for the duration of the call to +// the closure because we get it from an `Arc`, which means that the ref count will be at least 1, +// and we don't drop the `Arc` ourselves. If `queue_work_on` returns true, it is further guaranteed +// to be valid until a call to the function pointer in `work_struct` because we leak the memory it +// points to, and only reclaim it if the closure returns false, or in `WorkItemPointer::run`, which +// is what the function pointer in the `work_struct` must be pointing to, according to the safety +// requirements of `WorkItemPointer`. unsafe impl RawWorkItem for Arc where T: WorkItem, -- cgit v1.2.3 From 7a5f93ea5862da91488975acaa0c7abd508f192b Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sat, 23 Nov 2024 19:03:23 +0100 Subject: rust: kbuild: set `bindgen`'s Rust target version MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Each `bindgen` release may upgrade the list of Rust targets. For instance, currently, in their master branch [1], the latest ones are: Nightly => { vectorcall_abi: #124485, ptr_metadata: #81513, layout_for_ptr: #69835, }, Stable_1_77(77) => { offset_of: #106655 }, Stable_1_73(73) => { thiscall_abi: #42202 }, Stable_1_71(71) => { c_unwind_abi: #106075 }, Stable_1_68(68) => { abi_efiapi: #105795 }, By default, the highest stable release in their list is used, and users are expected to set one if they need to support older Rust versions (e.g. see [2]). Thus, over time, new Rust features are used by default, and at some point, it is likely that `bindgen` will emit Rust code that requires a Rust version higher than our minimum (or perhaps enabling an unstable feature). Currently, there is no problem because the maximum they have, as seen above, is Rust 1.77.0, and our current minimum is Rust 1.78.0. Therefore, set a Rust target explicitly now to prevent going forward in time too much and thus getting potential build failures at some point. Since we also support a minimum `bindgen` version, and since `bindgen` does not support passing unknown Rust target versions, we need to use the list of our minimum `bindgen` version, rather than the latest. So, since `bindgen` 0.65.1 had this list [3], we need to use Rust 1.68.0: /// Rust stable 1.64 /// * `core_ffi_c` ([Tracking issue](https://github.com/rust-lang/rust/issues/94501)) => Stable_1_64 => 1.64; /// Rust stable 1.68 /// * `abi_efiapi` calling convention ([Tracking issue](https://github.com/rust-lang/rust/issues/65815)) => Stable_1_68 => 1.68; /// Nightly rust /// * `thiscall` calling convention ([Tracking issue](https://github.com/rust-lang/rust/issues/42202)) /// * `vectorcall` calling convention (no tracking issue) /// * `c_unwind` calling convention ([Tracking issue](https://github.com/rust-lang/rust/issues/74990)) => Nightly => nightly; ... /// Latest stable release of Rust pub const LATEST_STABLE_RUST: RustTarget = RustTarget::Stable_1_68; Thus add the `--rust-target 1.68` parameter. Add a comment as well explaining this. An alternative would be to use the currently running (i.e. actual) `rustc` and `bindgen` versions to pick a "better" Rust target version. However, that would introduce more moving parts depending on the user setup and is also more complex to implement. Starting with `bindgen` 0.71.0 [4], 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. Christian implemented it [5] after seeing this patch. Thanks! Cc: Christian Poveda Cc: Emilio Cobos Álvarez Cc: stable@vger.kernel.org # needed for 6.12.y; unneeded for 6.6.y; do not apply to 6.1.y Fixes: c844fa64a2d4 ("rust: start supporting several `bindgen` versions") Link: https://github.com/rust-lang/rust-bindgen/blob/21c60f473f4e824d4aa9b2b508056320d474b110/bindgen/features.rs#L97-L105 [1] Link: https://github.com/rust-lang/rust-bindgen/issues/2960 [2] Link: https://github.com/rust-lang/rust-bindgen/blob/7d243056d335fdc4537f7bca73c06d01aae24ddc/bindgen/features.rs#L131-L150 [3] Link: https://github.com/rust-lang/rust-bindgen/blob/main/CHANGELOG.md#0710-2024-12-06 [4] Link: https://github.com/rust-lang/rust-bindgen/pull/2993 [5] Reviewed-by: Alice Ryhl Link: https://lore.kernel.org/r/20241123180323.255997-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- rust/Makefile | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'rust') diff --git a/rust/Makefile b/rust/Makefile index 9da9042fd627..a40a3936126d 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -280,9 +280,22 @@ 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. quiet_cmd_bindgen = BINDGEN $@ cmd_bindgen = \ - $(BINDGEN) $< $(bindgen_target_flags) \ + $(BINDGEN) $< $(bindgen_target_flags) --rust-target 1.68 \ --use-core --with-derive-default --ctypes-prefix ffi --no-layout-tests \ --no-debug '.*' --enable-function-attribute-detection \ -o $@ -- $(bindgen_c_flags_final) -DMODULE \ -- cgit v1.2.3 From 94901b7a74d82bfd30420f1d9d00898278fdc8bf Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Thu, 12 Dec 2024 22:00:15 +0900 Subject: rust: net::phy fix module autoloading The alias symbol name was renamed. Adjust module_phy_driver macro to create the proper symbol name to fix module autoloading. Fixes: 054a9cd395a7 ("modpost: rename alias symbol for MODULE_DEVICE_TABLE()") Signed-off-by: FUJITA Tomonori Link: https://patch.msgid.link/20241212130015.238863-1-fujita.tomonori@gmail.com Signed-off-by: Paolo Abeni --- rust/kernel/net/phy.rs | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'rust') diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs index b89c681d97c0..2fbfb6a94c11 100644 --- a/rust/kernel/net/phy.rs +++ b/rust/kernel/net/phy.rs @@ -860,7 +860,7 @@ impl DeviceMask { /// ]; /// #[cfg(MODULE)] /// #[no_mangle] -/// static __mod_mdio__phydev_device_table: [::kernel::bindings::mdio_device_id; 2] = _DEVICE_TABLE; +/// static __mod_device_table__mdio__phydev: [::kernel::bindings::mdio_device_id; 2] = _DEVICE_TABLE; /// ``` #[macro_export] macro_rules! module_phy_driver { @@ -883,7 +883,7 @@ macro_rules! module_phy_driver { #[cfg(MODULE)] #[no_mangle] - static __mod_mdio__phydev_device_table: [$crate::bindings::mdio_device_id; + static __mod_device_table__mdio__phydev: [$crate::bindings::mdio_device_id; $crate::module_phy_driver!(@count_devices $($dev),+) + 1] = _DEVICE_TABLE; }; -- cgit v1.2.3