From: Andi Kleen <andi@firstfloor.org>

Symbols referenced from assembler (either directly or e.f. from
DEFINE_STATIC_KEY()) need to be global and visible in gcc LTO because
they could end up in a different object file than the assembler. This
can lead to linker errors without this patch.

So mark preempt_schedule_thunk() and preempt_schedule_notrace_thunk() as
__visible.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Signed-off-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Martin Liska <mliska@suse.cz>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 arch/x86/include/asm/preempt.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h
index 5f6daea1ee24..c76ec881b23c 100644
--- a/arch/x86/include/asm/preempt.h
+++ b/arch/x86/include/asm/preempt.h
@@ -106,13 +106,13 @@ static __always_inline bool should_resched(int preempt_offset)
 #ifdef CONFIG_PREEMPTION
 
 extern asmlinkage void preempt_schedule(void);
-extern asmlinkage void preempt_schedule_thunk(void);
+extern __visible asmlinkage void preempt_schedule_thunk(void);
 
 #define preempt_schedule_dynamic_enabled	preempt_schedule_thunk
 #define preempt_schedule_dynamic_disabled	NULL
 
 extern asmlinkage void preempt_schedule_notrace(void);
-extern asmlinkage void preempt_schedule_notrace_thunk(void);
+extern __visible asmlinkage void preempt_schedule_notrace_thunk(void);
 
 #define preempt_schedule_notrace_dynamic_enabled	preempt_schedule_notrace_thunk
 #define preempt_schedule_notrace_dynamic_disabled	NULL
-- 
2.38.1