From a2ba7cc0be7c03b919d90624414b2d202f05b035 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sat, 17 Feb 2024 01:27:17 +0100 Subject: [PATCH] rust: upgrade to Rust 1.77.0 This is the next upgrade to the Rust toolchain, from 1.76.0 to 1.77.0 (i.e. the latest) [1]. See the upgrade policy [2] and the comments on the first upgrade in commit 3ed03f4da06e ("rust: upgrade to Rust 1.68.2"). The `offset_of` feature (single-field `offset_of!`) that we were using got stabilized in Rust 1.77.0 [3]. Therefore, now the only unstable features allowed to be used outside the `kernel` crate is `new_uninit`, though other code to be upstreamed may increase the list. Please see [4] for details. Rust 1.77.0 merged the `unused_tuple_struct_fields` lint into `dead_code`, thus upgrading it from `allow` to `warn` [5]. In turn, this makes `rustc` complain about the `ThisModule`'s pointer field being never read. Thus locally `allow` it for the moment, since we will have users later on (e.g. Binder needs a `as_ptr` method [6]). Rust 1.77.0 introduces the `--check-cfg` feature [7], for which there is a Call for Testing going on [8]. We were requested to test it and we found it useful [9] -- we will likely enable it in the future. The vast majority of changes are due to our `alloc` fork being upgraded at once. There are two kinds of changes to be aware of: the ones coming from upstream, which we should follow as closely as possible, and the updates needed in our added fallible APIs to keep them matching the newer infallible APIs coming from upstream. Instead of taking a look at the diff of this patch, an alternative approach is reviewing a diff of the changes between upstream `alloc` and the kernel's. This allows to easily inspect the kernel additions only, especially to check if the fallible methods we already have still match the infallible ones in the new version coming from upstream. Another approach is reviewing the changes introduced in the additions in the kernel fork between the two versions. This is useful to spot potentially unintended changes to our additions. To apply these approaches, one may follow steps similar to the following to generate a pair of patches that show the differences between upstream Rust and the kernel (for the subset of `alloc` we use) before and after applying this patch: # Get the difference with respect to the old version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > old.patch git -C linux restore rust/alloc # Apply this patch. git -C linux am rust-upgrade.patch # Get the difference with respect to the new version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > new.patch git -C linux restore rust/alloc Now one may check the `new.patch` to take a look at the additions (first approach) or at the difference between those two patches (second approach). For the latter, a side-by-side tool is recommended. Link: https://github.com/rust-lang/rust/blob/stable/RELEASES.md#version-1770-2024-03-21 [1] Link: https://rust-for-linux.com/rust-version-policy [2] Link: https://github.com/rust-lang/rust/pull/118799 [3] Link: https://github.com/Rust-for-Linux/linux/issues/2 [4] Link: https://github.com/rust-lang/rust/pull/118297 [5] Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-2-08ba9197f637@google.com/#Z31rust:kernel:lib.rs [6] Link: https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html [7] Link: https://github.com/rust-lang/rfcs/pull/3013#issuecomment-1936648479 [8] Link: https://github.com/rust-lang/rust/issues/82450#issuecomment-1947462977 [9] Signed-off-by: Miguel Ojeda Link: https://lore.kernel.org/r/20240217002717.57507-1-ojeda@kernel.org [boqun: Resolve the conflicts with using upstream alloc] --- Documentation/process/changes.rst | 2 +- rust/kernel/lib.rs | 3 +-- scripts/Makefile.build | 2 +- scripts/min-tool-version.sh | 2 +- 4 files changed, 4 insertions(+), 5 deletions(-) diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst index 7ef8de58f7f892..879ee628893ae1 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 5.1 gcc --version Clang/LLVM (optional) 13.0.1 clang --version -Rust (optional) 1.76.0 rustc --version +Rust (optional) 1.77.0 rustc --version bindgen (optional) 0.65.1 bindgen --version GNU make 3.82 make --version bash 4.2 bash --version diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 5c641233e26de4..e1e243f805dfe7 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -15,7 +15,6 @@ #![feature(coerce_unsized)] #![feature(dispatch_from_dyn)] #![feature(new_uninit)] -#![feature(offset_of)] #![feature(receiver_trait)] #![feature(unsize)] @@ -75,7 +74,7 @@ pub trait Module: Sized + Sync { /// Equivalent to `THIS_MODULE` in the C API. /// /// C header: [`include/linux/export.h`](srctree/include/linux/export.h) -pub struct ThisModule(*mut bindings::module); +pub struct ThisModule(#[allow(dead_code)] *mut bindings::module); // SAFETY: `THIS_MODULE` may be used from all threads within a module. unsafe impl Sync for ThisModule {} diff --git a/scripts/Makefile.build b/scripts/Makefile.build index baf86c0880b6d7..367cfeea74c5f5 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -263,7 +263,7 @@ $(obj)/%.lst: $(src)/%.c FORCE # Compile Rust sources (.rs) # --------------------------------------------------------------------------- -rust_allowed_features := new_uninit,offset_of +rust_allowed_features := new_uninit # `--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 diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh index 5927cc6b7de338..cc5141b67b4a71 100755 --- a/scripts/min-tool-version.sh +++ b/scripts/min-tool-version.sh @@ -33,7 +33,7 @@ llvm) fi ;; rustc) - echo 1.76.0 + echo 1.77.0 ;; bindgen) echo 0.65.1