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-rw-r--r--arch/x86/include/asm/alternative.h8
-rw-r--r--arch/x86/kernel/alternative.c6
2 files changed, 9 insertions, 5 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index 3b5b828..55fee12 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -28,12 +28,14 @@
*/
#ifdef CONFIG_SMP
-#define LOCK_PREFIX \
+#define LOCK_PREFIX_HERE \
".section .smp_locks,\"a\"\n" \
_ASM_ALIGN "\n" \
- _ASM_PTR "661f\n" /* address */ \
+ _ASM_PTR "671f\n" /* address */ \
".previous\n" \
- "661:\n\tlock; "
+ "671:"
+
+#define LOCK_PREFIX LOCK_PREFIX_HERE "\n\tlock; "
#else /* ! CONFIG_SMP */
#define LOCK_PREFIX ""
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 2589ea4..80b222e 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);
}