FAILED: patch "[PATCH] rust: hrtimer: declare cfi_encoding for hrtimer_restart" failed to apply to 6.18-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 6.18-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-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 39fe6892fd52faed6325ff7f13a92da01ab35727
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026110416-donut-counting-ca1b@gregkh' --subject-prefix 'PATCH 6.18.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From 39fe6892fd52faed6325ff7f13a92da01ab35727 Mon Sep 17 00:00:00 2001
From: Sami Tolvanen <samitolvanen@google.com>
Date: Mon, 19 Oct 2026 23:34:38 +0000
Subject: [PATCH] rust: hrtimer: declare cfi_encoding for hrtimer_restart

The hrtimer callbacks return bindings::hrtimer_restart, which bindgen
generates as c_uint. C calls them through hrtimer->function, which
returns enum hrtimer_restart. kCFI encodes enum types by name even with
integer normalization, so the type ids never match and every call fails
the CFI check.

Generate hrtimer_restart as a newtype with a cfi_encoding, as is done
for lru_status, and adapt HrTimerRestart to the newtype.

Fixes: 8a8afe9349fb ("rust: hrtimer: introduce hrtimer support")
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Tested-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Acked-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20261019-rust-cfi-fixes-v1-2-9503472ba738@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

diff --git a/rust/bindgen_parameters b/rust/bindgen_parameters
index 5059cc74cb3c..6003d5127676 100644
--- a/rust/bindgen_parameters
+++ b/rust/bindgen_parameters
@@ -27,6 +27,8 @@
 --opaque-type spinlock
 
 # enums that appear in indirect function calls should specify a cfi type
+--newtype-enum hrtimer_restart
+--with-attribute-custom-enum=hrtimer_restart='#[cfi_encoding="15hrtimer_restart"]'
 --newtype-enum irqreturn
 --with-attribute-custom-enum=irqreturn='#[cfi_encoding="9irqreturn"]'
 --newtype-enum lru_status
diff --git a/rust/kernel/time/hrtimer.rs b/rust/kernel/time/hrtimer.rs
index 2d7f1131a813..07344ed5fbd5 100644
--- a/rust/kernel/time/hrtimer.rs
+++ b/rust/kernel/time/hrtimer.rs
@@ -834,14 +834,14 @@ unsafe fn start(this: *const Self, expires: <Self::TimerMode as HrTimerMode>::Ex
 #[repr(u32)]
 pub enum HrTimerRestart {
     /// Timer should not be restarted.
-    NoRestart = bindings::hrtimer_restart_HRTIMER_NORESTART,
+    NoRestart = bindings::hrtimer_restart::HRTIMER_NORESTART.0,
     /// Timer should be restarted.
-    Restart = bindings::hrtimer_restart_HRTIMER_RESTART,
+    Restart = bindings::hrtimer_restart::HRTIMER_RESTART.0,
 }
 
 impl HrTimerRestart {
     fn into_c(self) -> bindings::hrtimer_restart {
-        self as bindings::hrtimer_restart
+        bindings::hrtimer_restart(self as c_uint)
     }
 }