1 files changed, 4 insertions, 2 deletions

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 2589ea4c60ce..80b222ea4cf6 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -244,7 +244,8 @@ static void alternatives_smp_lock(u8 **start, u8 **end, u8 *text, u8 *text_end)
                 if (*ptr > text_end)
                         continue;
                 /* turn DS segment override prefix into lock prefix */
-                text_poke(*ptr, ((unsigned char []){0xf0}), 1);
+                if (**ptr == 0x3e)
+                        text_poke(*ptr, ((unsigned char []){0xf0}), 1);
         };
         mutex_unlock(&text_mutex);
 }
@@ -263,7 +264,8 @@ static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end
                 if (*ptr > text_end)
                         continue;
                 /* turn lock prefix into DS segment override prefix */
-                text_poke(*ptr, ((unsigned char []){0x3E}), 1);
+                if (**ptr == 0xf0)
+                        text_poke(*ptr, ((unsigned char []){0x3E}), 1);
         };
         mutex_unlock(&text_mutex);
 }