[RFC PATCH v2 01/13] arm64: Always inline raw preempt count updates

[Karl Mehltretter]

From: Hongyan Xia <hongyan.xia at transsion.com>

Clang can outline the raw preempt count helpers from noinstr callers into
ordinary instrumentable text. Force the add and subtract operations inline
so entry code performs the count update in its own noinstr section.

This is the preempt-count hunk from Hongyan Xia's pending Kprobe noinstr
RFC. Keep it as a separate prerequisite so the early-hardirq work neither
hides nor claims that fix.

Link: https://lore.kernel.org/all/c3a90368dd6c096af9d918e036a27728696fb8a4.1786603168.git.hongyan.xia@transsion.com/
Signed-off-by: Hongyan Xia <hongyan.xia at transsion.com>
---
 arch/arm64/include/asm/preempt.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/preempt.h b/arch/arm64/include/asm/preempt.h
index 75a592b7f47f7..f3a5c2cd1936d 100644
--- a/arch/arm64/include/asm/preempt.h
+++ b/arch/arm64/include/asm/preempt.h
@@ -41,14 +41,14 @@ static inline bool test_preempt_need_resched(void)
 	return !current_thread_info()->preempt.need_resched;
 }
 
-static inline void __preempt_count_add(int val)
+static __always_inline void __preempt_count_add(int val)
 {
 	u32 pc = READ_ONCE(current_thread_info()->preempt.count);
 	pc += val;
 	WRITE_ONCE(current_thread_info()->preempt.count, pc);
 }
 
-static inline void __preempt_count_sub(int val)
+static __always_inline void __preempt_count_sub(int val)
 {
 	u32 pc = READ_ONCE(current_thread_info()->preempt.count);
 	pc -= val;
-- 
2.39.5 (Apple Git-154)