+From fad472efab0a805dd939f017c5b8669a786a4bcf Mon Sep 17 00:00:00 2001
+From: Miguel Ojeda <ojeda@kernel.org>
+Date: Sun, 2 Nov 2025 22:28:53 +0100
+Subject: rust: kbuild: workaround `rustdoc` doctests modifier bug
+
+From: Miguel Ojeda <ojeda@kernel.org>
+
+commit fad472efab0a805dd939f017c5b8669a786a4bcf upstream.
+
+The `rustdoc` modifiers bug [1] was fixed in Rust 1.90.0 [2], for which
+we added a workaround in commit abbf9a449441 ("rust: workaround `rustdoc`
+target modifiers bug").
+
+However, `rustdoc`'s doctest generation still has a similar issue [3],
+being fixed at [4], which does not affect us because we apply the
+workaround to both, and now, starting with Rust 1.91.0 (released
+2025-10-30), `-Zsanitizer` is a target modifier too [5], which means we
+fail with:
+
+ RUSTDOC TK rust/kernel/lib.rs
+ error: mixing `-Zsanitizer` will cause an ABI mismatch in crate `kernel`
+ --> rust/kernel/lib.rs:3:1
+ |
+ 3 | //! The `kernel` crate.
+ | ^
+ |
+ = 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
+
+A simple way around is to add the sanitizer to the list in the existing
+workaround (especially if we had not started to pass the sanitizer
+flags in the previous commit, since in that case that would not be
+necessary). However, that still applies the workaround in more cases
+than necessary.
+
+Instead, only modify the doctests flags to ignore the check for
+sanitizers, so that it is more local (and thus the compiler keeps checking
+it for us in the normal `rustdoc` calls). Since the previous commit
+already treated the `rustdoc` calls as kernel objects, this should allow
+us in the future to easily remove this workaround when the time comes.
+
+By the way, the `-Cunsafe-allow-abi-mismatch` flag overwrites previous
+ones rather than appending, so it needs to be all done in the same flag.
+Moreover, unknown modifiers are rejected, and thus we have to gate based
+on the version too.
+
+Finally, `-Zsanitizer-cfi-normalize-integers` is not affected (in Rust
+1.91.0), so it is not needed in the workaround for the moment.
+
+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/issues/144521 [1]
+Link: https://github.com/rust-lang/rust/pull/144523 [2]
+Link: https://github.com/rust-lang/rust/issues/146465 [3]
+Link: https://github.com/rust-lang/rust/pull/148068 [4]
+Link: https://github.com/rust-lang/rust/pull/138736 [5]
+Reviewed-by: Alice Ryhl <aliceryhl@google.com>
+Tested-by: Justin M. Forbes <jforbes@fedoraproject.org>
+Link: https://patch.msgid.link/20251102212853.1505384-2-ojeda@kernel.org
+Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ rust/Makefile | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+--- a/rust/Makefile
++++ b/rust/Makefile
+@@ -69,6 +69,9 @@ core-edition := $(if $(call rustc-min-ve
+ # the time being (https://github.com/rust-lang/rust/issues/144521).
+ rustdoc_modifiers_workaround := $(if $(call rustc-min-version,108800),-Cunsafe-allow-abi-mismatch=fixed-x18)
+
++# 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
+@@ -224,7 +227,7 @@ quiet_cmd_rustdoc_test_kernel = RUSTDOC
+ --extern bindings --extern uapi \
+ --no-run --crate-name kernel -Zunstable-options \
+ --sysroot=/dev/null \
+- $(rustdoc_modifiers_workaround) \
++ $(doctests_modifiers_workaround) \
+ --test-builder $(objtree)/scripts/rustdoc_test_builder \
+ $< $(rustdoc_test_kernel_quiet); \
+ $(objtree)/scripts/rustdoc_test_gen
projects / thirdparty / kernel / stable-queue.git / commitdiff
