[tip: x86/urgent] um: Add missing apply_returns()

[tip-bot2 for Peter Zijlstra]

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID:     564d998106397394b6aad260f219b882b3347e62
Gitweb:        https://git.kernel.org/tip/564d998106397394b6aad260f219b882b3347e62
Author:        Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate:    Thu, 14 Jul 2022 12:20:19 +02:00
Committer:     Borislav Petkov <bp@xxxxxxx>
CommitterDate: Thu, 14 Jul 2022 13:40:21 +02:00

um: Add missing apply_returns()

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@xxxxxxxxxxxxx)
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Link: https://lore.kernel.org/r/Ys%2Ft45l%2FgarIrD0u@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
---
 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 0760e24..9838967 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -432,6 +432,10 @@ 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)
 {
 }