6.17-stable review patch. If anyone has any objections, please let me know.
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From: Miguel Ojeda ojeda@kernel.org
commit dbdf2a7feb422f9bacfd12774e624cf26f503eb0 upstream.
Between Rust 1.79 and 1.86, under `CONFIG_RUST_KERNEL_DOCTESTS=y`, `objtool` may report:
rust/doctests_kernel_generated.o: warning: objtool: rust_doctest_kernel_alloc_kbox_rs_13() falls through to next function rust_doctest_kernel_alloc_kvec_rs_0()
(as well as in rust_doctest_kernel_alloc_kvec_rs_0) due to calls to the `noreturn` symbol:
core::option::expect_failed
from code added in commits 779db37373a3 ("rust: alloc: kvec: implement AsPageIter for VVec") and 671618432f46 ("rust: alloc: kbox: implement AsPageIter for VBox").
Thus add the mangled one to the list so that `objtool` knows it is actually `noreturn`.
This can be reproduced as well in other versions by tweaking the code, such as the latest stable Rust (1.90.0).
Stable does not have code that triggers this, but it could have it in the future. Downstream forks could too. Thus tag it for backport.
See commit 56d680dd23c3 ("objtool/rust: list `noreturn` Rust functions") for more details.
Signed-off-by: Miguel Ojeda ojeda@kernel.org Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Reviewed-by: Alice Ryhl aliceryhl@google.com Cc: stable@vger.kernel.org # Needed in 6.12.y and later. Link: https://patch.msgid.link/20251020020714.2511718-1-ojeda@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/objtool/check.c | 1 + 1 file changed, 1 insertion(+)
--- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -217,6 +217,7 @@ static bool is_rust_noreturn(const struc * these come from the Rust standard library). */ return str_ends_with(func->name, "_4core5sliceSp15copy_from_slice17len_mismatch_fail") || + str_ends_with(func->name, "_4core6option13expect_failed") || str_ends_with(func->name, "_4core6option13unwrap_failed") || str_ends_with(func->name, "_4core6result13unwrap_failed") || str_ends_with(func->name, "_4core9panicking5panic") ||