[PATCH 2/3] rust: hrtimer: declare cfi_encoding for hrtimer_restart

[Sami Tolvanen <samitolvanen@google.com>]

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>
---
 rust/bindgen_parameters     | 2 ++
 rust/kernel/time/hrtimer.rs | 6 +++---
 2 files changed, 5 insertions(+), 3 deletions(-)

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)
     }
 }
 

-- 
2.56.0.212.g129ede20d9-goog