From 37e95ded40b02cd65f68d2081cb6a5d1593c14d2 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Thu, 14 Jul 2022 12:20:19 +0200
Subject: [PATCH] um: Add missing apply_returns()

commit 564d998106397394b6aad260f219b882b3347e62 upstream.

Implement apply_returns() stub for UM, just like all the other patching
routines.

Fixes: 15e67227c49a ("x86: Undo return-thunk damage")
Reported-by: Randy Dunlap <rdunlap@infradead.org)
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/Ys%2Ft45l%2FgarIrD0u@worktop.programming.kicks-ass.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/um/kernel/um_arch.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 54447690de11..5aa5e7533b75 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -425,6 +425,10 @@ void apply_retpolines(s32 *start, s32 *end)
 {
 }
 
+void apply_returns(s32 *start, s32 *end)
+{
+}
+
 void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
 {
 }