From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 8 Mar 2023 16:29:38 +0100
Subject: [PATCH] preempt: Put preempt_enable() within an instrumentation*()
 section.
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz

Callers of preempt_enable() can be within an noinstr section leading to:
| vmlinux.o: warning: objtool: native_sched_clock+0x97: call to preempt_schedule_notrace_thunk() leaves .noinstr.text section
| vmlinux.o: warning: objtool: kvm_clock_read+0x22: call to preempt_schedule_notrace_thunk() leaves .noinstr.text section
| vmlinux.o: warning: objtool: local_clock+0xb4: call to preempt_schedule_notrace_thunk() leaves .noinstr.text section
| vmlinux.o: warning: objtool: enter_from_user_mode+0xea: call to preempt_schedule_thunk() leaves .noinstr.text section
| vmlinux.o: warning: objtool: syscall_enter_from_user_mode+0x140: call to preempt_schedule_thunk() leaves .noinstr.text section
| vmlinux.o: warning: objtool: syscall_enter_from_user_mode_prepare+0xf2: call to preempt_schedule_thunk() leaves .noinstr.text section
| vmlinux.o: warning: objtool: irqentry_enter_from_user_mode+0xea: call to preempt_schedule_thunk() leaves .noinstr.text section

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20230309072724.3F6zRkvw@linutronix.de
---
 include/linux/preempt.h |   10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -230,15 +230,21 @@ do { \
 #define preempt_enable() \
 do { \
 	barrier(); \
-	if (unlikely(preempt_count_dec_and_test())) \
+	if (unlikely(preempt_count_dec_and_test())) { \
+		instrumentation_begin(); \
 		__preempt_schedule(); \
+		instrumentation_end(); \
+	} \
 } while (0)
 
 #define preempt_enable_notrace() \
 do { \
 	barrier(); \
-	if (unlikely(__preempt_count_dec_and_test())) \
+	if (unlikely(__preempt_count_dec_and_test())) { \
+		instrumentation_begin(); \
 		__preempt_schedule_notrace(); \
+		instrumentation_end(); \
+	} \
 } while (0)
 
 #define preempt_check_resched() \
