[PATCH v4 5/8] rv/ha: make da_monitor_reset_hook and EVENT_NONE_LBL overridable

[wen.yang@linux.dev]

From: Wen Yang <wen.yang@linux.dev>

Wrap both definitions with #ifndef guards so HA-based monitors can
substitute their own implementations before including this header.
tlob uses this to define a reset hook that cancels per-task hrtimers
on monitor teardown.

Overrides must still call ha_monitor_reset_env() or cancel outstanding
timers to avoid timer UAF.

No behaviour change for monitors that do not override either macro.

Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Wen Yang <wen.yang@linux.dev>
---
 include/rv/ha_monitor.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/include/rv/ha_monitor.h b/include/rv/ha_monitor.h
index dddf5694bcc8..6d526eef8348 100644
--- a/include/rv/ha_monitor.h
+++ b/include/rv/ha_monitor.h
@@ -36,7 +36,15 @@ static bool ha_monitor_handle_constraint(struct da_monitor *da_mon,
 					 da_id_type id);
 #define da_monitor_event_hook ha_monitor_handle_constraint
 #define da_monitor_init_hook ha_monitor_init_env
+
+/*
+ * Allow monitors to override da_monitor_reset_hook before including this
+ * header. The override must still call ha_monitor_reset_env() or cancel
+ * timers explicitly.
+ */
+#ifndef da_monitor_reset_hook
 #define da_monitor_reset_hook ha_monitor_reset_env
+#endif
 #define da_monitor_sync_hook() synchronize_rcu()
 
 #if !defined(HA_SKIP_AUTO_CLEANUP) && RV_MON_TYPE == RV_MON_PER_TASK
@@ -75,7 +83,9 @@ _Static_assert(offsetof(struct ha_monitor, da_mon) == 0,
 #define ENV_INVALID_VALUE U64_MAX
 /* Error with no event occurs only on timeouts */
 #define EVENT_NONE EVENT_MAX
+#ifndef EVENT_NONE_LBL
 #define EVENT_NONE_LBL "none"
+#endif
 #define ENV_BUFFER_SIZE 64
 
 #ifdef CONFIG_RV_REACTORS
-- 
2.25.1