6.12-stable review patch. If anyone has any objections, please let me know.
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From: Miguel Ojeda ojeda@kernel.org
[ Upstream commit 16c43a56b79e2c3220b043236369a129d508c65a ]
Even if normally `build_error` isn't a kernel object, it should still be treated as such so that we pass the same flags. Similarly, `rustdoc` targets are never kernel objects, but we need to treat them as such.
Otherwise, starting with Rust 1.91.0 (released 2025-10-30), `rustc` will complain about missing sanitizer flags since `-Zsanitizer` is a target modifier too [1]:
error: mixing `-Zsanitizer` will cause an ABI mismatch in crate `build_error` --> rust/build_error.rs:3:1 | 3 | //! Build-time error. | ^ | = help: the `-Zsanitizer` flag modifies the ABI so Rust crates compiled with different values of this flag cannot be used together safely = note: unset `-Zsanitizer` in this crate is incompatible with `-Zsanitizer=kernel-address` in dependency `core` = help: set `-Zsanitizer=kernel-address` in this crate or unset `-Zsanitizer` in `core` = help: if you are sure this will not cause problems, you may use `-Cunsafe-allow-abi-mismatch=sanitizer` to silence this error
Thus explicitly mark them as kernel objects.
Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs). Link: https://github.com/rust-lang/rust/pull/138736 [1] Reviewed-by: Alice Ryhl aliceryhl@google.com Tested-by: Justin M. Forbes jforbes@fedoraproject.org Link: https://patch.msgid.link/20251102212853.1505384-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda ojeda@kernel.org [ Adjust context ] Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- rust/Makefile | 10 ++++++++++ 1 file changed, 10 insertions(+)
--- a/rust/Makefile +++ b/rust/Makefile @@ -107,12 +107,18 @@ rustdoc-core: private rustc_target_flags rustdoc-core: $(RUST_LIB_SRC)/core/src/lib.rs rustdoc-clean FORCE +$(call if_changed,rustdoc)
+# Even if `rustdoc` targets are not kernel objects, they should still be +# treated as such so that we pass the same flags. Otherwise, for instance, +# `rustdoc` will complain about missing sanitizer flags causing an ABI mismatch. +rustdoc-compiler_builtins: private is-kernel-object := y rustdoc-compiler_builtins: $(src)/compiler_builtins.rs rustdoc-core FORCE +$(call if_changed,rustdoc)
+rustdoc-ffi: private is-kernel-object := y rustdoc-ffi: $(src)/ffi.rs rustdoc-core FORCE +$(call if_changed,rustdoc)
+rustdoc-kernel: private is-kernel-object := y rustdoc-kernel: private rustc_target_flags = --extern ffi \ --extern build_error --extern macros=$(objtree)/$(obj)/libmacros.so \ --extern bindings --extern uapi @@ -433,6 +439,10 @@ $(obj)/compiler_builtins.o: private rust $(obj)/compiler_builtins.o: $(src)/compiler_builtins.rs $(obj)/core.o FORCE +$(call if_changed_rule,rustc_library)
+# Even if normally `build_error` is not a kernel object, it should still be +# treated as such so that we pass the same flags. Otherwise, for instance, +# `rustc` will complain about missing sanitizer flags causing an ABI mismatch. +$(obj)/build_error.o: private is-kernel-object := y $(obj)/build_error.o: $(src)/build_error.rs $(obj)/compiler_builtins.o FORCE +$(call if_changed_rule,rustc_library)