FAILED: patch "[PATCH] objtool/rust: add one more `noreturn` Rust function for Rust 1.101.0" failed to apply to 6.6-stable tree

FAILED: patch "[PATCH] objtool/rust: add one more `noreturn` Rust function for Rust 1.101.0" failed to apply to 6.6-stable tree

[Sasha Levin]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 6b704ec9007a3f23ec5ded8f320825ac444f307d
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '20261107053746-failed-6.6-6b704ec9007a@kernel.org' --subject-prefix 'PATCH 6.6.y' 'HEAD^..'

Thanks,
Sasha

------------------ original commit in Linus's tree ------------------

From 6b704ec9007a3f23ec5ded8f320825ac444f307d Mon Sep 17 00:00:00 2001
From: Miguel Ojeda <ojeda@kernel.org>
Date: Sun, 18 Oct 2026 15:13:13 +0200
Subject: [PATCH] objtool/rust: add one more `noreturn` Rust function for Rust
 1.101.0

Starting with Rust 1.101.0 (expected 2026-12-24), `objtool` may report:

    rust/kernel.o: warning: objtool: _R..._4core6result13unwrap_failed...()
    falls through to next function _R..._4core6result13unwrap_failed...()

(and others) due to calls to the `noreturn` symbol:

    core::result::unwrap_failed::unwrap_failed_inner

Rust introduced this helper when making `unwrap_failed` generic [1]. The
existing entry for `unwrap_failed` does not match the new helper.

Thus add the mangled one to the list so that `objtool` knows it is
actually `noreturn`.

See commit 56d680dd23c3 ("objtool/rust: list `noreturn` Rust functions")
for more details.

Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://github.com/rust-lang/rust/pull/164059 [1]
Assisted-by: LLM
Link: https://patch.msgid.link/20261018131313.59391-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 tools/objtool/check.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 464f6c9d9ff0b..931c5c412f15d 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -201,6 +201,7 @@ static bool is_rust_noreturn(const struct symbol *func)
 	       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, "_4core6result13unwrap_failed19unwrap_failed_inner")		||
 	       str_ends_with(func->name, "_4core9panicking5panic")					||
 	       str_ends_with(func->name, "_4core9panicking9panic_fmt")					||
 	       str_ends_with(func->name, "_4core9panicking14panic_explicit")				||
-- 
2.53.0

Re: FAILED: patch "[PATCH] objtool/rust: add one more `noreturn` Rust function for Rust 1.101.0" failed to apply to 6.6-stable tree

[Miguel Ojeda]

On Sat, Nov 7, 2026 at 11:37 AM Sasha Levin <sashal@kernel.org> wrote:
>
> Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).

6.6 has Rust, but the version is pinned, thus it will not need these
(if we were to change that, we would need to backport others anyway).

Cheers,
Miguel