diff options
| author |   Miguel Ojeda <ojeda@kernel.org> | 2025-07-27 11:23:17 +0200 |
|---|---|---|
| committer | Miguel Ojeda <ojeda@kernel.org> | 2025-08-12 21:06:48 +0200 |
| commit | abbf9a44944171ca99c150adad9361a2f517d3b6 (patch) | |
| tree | 915ff46a4018a3a1d16ae71645537a8fcf6e551e | |
| parent | Linux 6.17-rc1 (diff) | |
| download | wireguard-linux-abbf9a44944171ca99c150adad9361a2f517d3b6.tar.xz wireguard-linux-abbf9a44944171ca99c150adad9361a2f517d3b6.zip | |
rust: workaround `rustdoc` target modifiers bug
Starting with Rust 1.88.0 (released 2025-06-26), `rustdoc` complains
about a target modifier mismatch in configurations where `-Zfixed-x18`
is passed:
error: mixing `-Zfixed-x18` will cause an ABI mismatch in crate `rust_out`
|
= help: the `-Zfixed-x18` flag modifies the ABI so Rust crates compiled with different values of this flag cannot be used together safely
= note: unset `-Zfixed-x18` in this crate is incompatible with `-Zfixed-x18=` in dependency `core`
= help: set `-Zfixed-x18=` in this crate or unset `-Zfixed-x18` in `core`
= help: if you are sure this will not cause problems, you may use `-Cunsafe-allow-abi-mismatch=fixed-x18` to silence this error
The reason is that `rustdoc` was not passing the target modifiers when
configuring the session options, and thus it would report a mismatch
that did not exist as soon as a target modifier is used in a dependency.
We did not notice it in the kernel until now because `-Zfixed-x18` has
been a target modifier only since 1.88.0 (and it is the only one we use
so far).
The issue has been reported upstream [1] and a fix has been submitted
[2], including a test similar to the kernel case.
[ This is now fixed upstream (thanks Guillaume for the quick review),
so it will be fixed in Rust 1.90.0 (expected 2025-09-18).
- Miguel ]
Meanwhile, conditionally pass `-Cunsafe-allow-abi-mismatch=fixed-x18`
to workaround the issue on our side.
Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Reported-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Closes: https://lore.kernel.org/rust-for-linux/36cdc798-524f-4910-8b77-d7b9fac08d77@oss.qualcomm.com/
Link: https://github.com/rust-lang/rust/issues/144521 [1]
Link: https://github.com/rust-lang/rust/pull/144523 [2]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250727092317.2930617-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
| -rw-r--r-- | rust/Makefile | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/rust/Makefile b/rust/Makefile index 4263462b8470..d47f82588d78 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -65,6 +65,10 @@ core-cfgs = \ core-edition := $(if $(call rustc-min-version,108700),2024,2021) +# `rustdoc` did not save the target modifiers, thus workaround for +# 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) + # `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 @@ -77,6 +81,7 @@ quiet_cmd_rustdoc = RUSTDOC $(if $(rustdoc_host),H, ) $< -Zunstable-options --generate-link-to-definition \ --output $(rustdoc_output) \ --crate-name $(subst rustdoc-,,$@) \ + $(rustdoc_modifiers_workaround) \ $(if $(rustdoc_host),,--sysroot=/dev/null) \ @$(objtree)/include/generated/rustc_cfg $< @@ -215,6 +220,7 @@ quiet_cmd_rustdoc_test_kernel = RUSTDOC TK $< --extern bindings --extern uapi \ --no-run --crate-name kernel -Zunstable-options \ --sysroot=/dev/null \ + $(rustdoc_modifiers_workaround) \ --test-builder $(objtree)/scripts/rustdoc_test_builder \ $< $(rustdoc_test_kernel_quiet); \ $(objtree)/scripts/rustdoc_test_gen |