From c5fed8ce65493f71611280f225826e7bd5e49791 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 24 Dec 2023 18:21:28 +0100 Subject: rust: upgrade to Rust 1.75.0 This is the next upgrade to the Rust toolchain, from 1.74.1 to 1.75.0 (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"). # Unstable features The `const_maybe_uninit_zeroed` unstable feature [3] was stabilized in Rust 1.75.0, which we were using in the PHYLIB abstractions. The only unstable features allowed to be used outside the `kernel` crate are still `new_uninit,offset_of`, though other code to be upstreamed may increase the list. Please see [4] for details. # Other improvements Rust 1.75.0 stabilized `pointer_byte_offsets` [5] which we could potentially use as an alternative for `ptr_metadata` in the future. # Required changes For this upgrade, no changes were required (i.e. on our side). # `alloc` upgrade and reviewing 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-1750-2023-12-28 [1] Link: https://rust-for-linux.com/rust-version-policy [2] Link: https://github.com/rust-lang/rust/issues/91850 [3] Link: https://github.com/Rust-for-Linux/linux/issues/2 [4] Link: https://github.com/rust-lang/rust/issues/96283 [5] Reviewed-by: Vincenzo Palazzo Reviewed-by: Martin Rodriguez Reboredo Tested-by: Boqun Feng Link: https://lore.kernel.org/r/20231224172128.271447-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- scripts/min-tool-version.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts') diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh index 9faa4d3d91e3..ef6f286a4d47 100755 --- a/scripts/min-tool-version.sh +++ b/scripts/min-tool-version.sh @@ -33,7 +33,7 @@ llvm) fi ;; rustc) - echo 1.74.1 + echo 1.75.0 ;; bindgen) echo 0.65.1 -- cgit From ecab4115c44cc50fc7320bef9c19ac01ad43c785 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sat, 17 Feb 2024 01:26:37 +0100 Subject: kbuild: mark `rustc` (and others) invocations as recursive `rustc` (like Cargo) may take advantage of the jobserver at any time (e.g. for backend parallelism, or eventually frontend too). In the kernel, we call `rustc` with `-Ccodegen-units=1` (and `-Zthreads` is 1 so far), so we do not expect parallelism. However, in the upcoming Rust 1.76.0, a warning is emitted by `rustc` [1] when it cannot connect to the jobserver it was passed (in many cases, but not all: compiling and `--print sysroot` do, but `--version` does not). And given GNU Make always passes the jobserver in the environment variable (even when a line is deemed non-recursive), `rustc` will end up complaining about it (in particular in Make 4.3 where there is only the simple pipe jobserver style). One solution is to remove the jobserver from `MAKEFLAGS`. However, we can mark the lines with calls to `rustc` (and Cargo) as recursive, which looks simpler. This is being documented as a recommendation in `rustc` [2] and allows us to be ready for the time we may use parallelism inside `rustc` (potentially now, if a user passes `-Zthreads`). Thus do so. Similarly, do the same for `rustdoc` and `cargo` calls. Finally, there is one case that the solution does not cover, which is the `$(shell ...)` call we have. Thus, for that one, set an empty `MAKEFLAGS` environment variable. Link: https://github.com/rust-lang/rust/issues/120515 [1] Acked-by: Masahiro Yamada Link: https://github.com/rust-lang/rust/pull/121564 [2] Link: https://lore.kernel.org/r/20240217002638.57373-1-ojeda@kernel.org [ Reworded to add link to PR documenting the recommendation. ] Signed-off-by: Miguel Ojeda --- scripts/Makefile.build | 8 ++++---- scripts/Makefile.host | 2 +- 2 files changed, 5 insertions(+), 5 deletions(-) (limited to 'scripts') diff --git a/scripts/Makefile.build b/scripts/Makefile.build index dae447a1ad30..0fb7a785594c 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -290,7 +290,7 @@ quiet_cmd_rustc_o_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@ cmd_rustc_o_rs = $(rust_common_cmd) --emit=obj=$@ $< $(obj)/%.o: $(src)/%.rs FORCE - $(call if_changed_dep,rustc_o_rs) + +$(call if_changed_dep,rustc_o_rs) quiet_cmd_rustc_rsi_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@ cmd_rustc_rsi_rs = \ @@ -298,19 +298,19 @@ quiet_cmd_rustc_rsi_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@ command -v $(RUSTFMT) >/dev/null && $(RUSTFMT) $@ $(obj)/%.rsi: $(src)/%.rs FORCE - $(call if_changed_dep,rustc_rsi_rs) + +$(call if_changed_dep,rustc_rsi_rs) quiet_cmd_rustc_s_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@ cmd_rustc_s_rs = $(rust_common_cmd) --emit=asm=$@ $< $(obj)/%.s: $(src)/%.rs FORCE - $(call if_changed_dep,rustc_s_rs) + +$(call if_changed_dep,rustc_s_rs) quiet_cmd_rustc_ll_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@ cmd_rustc_ll_rs = $(rust_common_cmd) --emit=llvm-ir=$@ $< $(obj)/%.ll: $(src)/%.rs FORCE - $(call if_changed_dep,rustc_ll_rs) + +$(call if_changed_dep,rustc_ll_rs) # Compile assembler sources (.S) # --------------------------------------------------------------------------- diff --git a/scripts/Makefile.host b/scripts/Makefile.host index 08d83d9db31a..3c17e6ba421c 100644 --- a/scripts/Makefile.host +++ b/scripts/Makefile.host @@ -156,7 +156,7 @@ quiet_cmd_host-rust = HOSTRUSTC $@ cmd_host-rust = \ $(HOSTRUSTC) $(hostrust_flags) --emit=link=$@ $< $(host-rust): $(obj)/%: $(src)/%.rs FORCE - $(call if_changed_dep,host-rust) + +$(call if_changed_dep,host-rust) targets += $(host-csingle) $(host-cmulti) $(host-cobjs) \ $(host-cxxmulti) $(host-cxxobjs) $(host-rust) -- cgit From 768409cff6cc89fe1194da880537a09857b6e4db Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sat, 17 Feb 2024 01:26:38 +0100 Subject: rust: upgrade to Rust 1.76.0 This is the next upgrade to the Rust toolchain, from 1.75.0 to 1.76.0 (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"). # Unstable features No unstable features that we use were stabilized in Rust 1.76.0. The only unstable features allowed to be used outside the `kernel` crate are still `new_uninit,offset_of`, though other code to be upstreamed may increase the list. Please see [3] for details. # Required changes `rustc` (and others) now warns when it cannot connect to the Make jobserver, thus mark those invocations as recursive as needed. Please see the previous commit for details. # Other changes Rust 1.76.0 does not emit the `.debug_pub{names,types}` sections anymore for DWARFv4 [4][5]. For instance, in the uncompressed debug info case, this debug information took: samples/rust/rust_minimal.o ~64 KiB (~18% of total object size) rust/kernel.o ~92 KiB (~15%) rust/core.o ~114 KiB ( ~5%) In the compressed debug info (zlib) case: samples/rust/rust_minimal.o ~11 KiB (~6%) rust/kernel.o ~17 KiB (~5%) rust/core.o ~21 KiB (~1.5%) In addition, the `rustc_codegen_gcc` backend now does not emit the `.eh_frame` section when compiling under `-Cpanic=abort` [6], thus removing the need for the patch in the CI to compile the kernel [7]. Moreover, it also now emits the `.comment` section too [6]. # `alloc` upgrade and reviewing 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-1760-2024-02-08 [1] Link: https://rust-for-linux.com/rust-version-policy [2] Link: https://github.com/Rust-for-Linux/linux/issues/2 [3] Link: https://github.com/rust-lang/compiler-team/issues/688 [4] Link: https://github.com/rust-lang/rust/pull/117962 [5] Link: https://github.com/rust-lang/rust/pull/118068 [6] Link: https://github.com/Rust-for-Linux/ci-rustc_codegen_gcc [7] Tested-by: Boqun Feng Reviewed-by: Alice Ryhl Link: https://lore.kernel.org/r/20240217002638.57373-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- scripts/min-tool-version.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'scripts') diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh index ef6f286a4d47..e217683b10d6 100755 --- a/scripts/min-tool-version.sh +++ b/scripts/min-tool-version.sh @@ -33,7 +33,7 @@ llvm) fi ;; rustc) - echo 1.75.0 + echo 1.76.0 ;; bindgen) echo 0.65.1 -- cgit