x86/spectre: Check CONFIG_RETPOLINE in command line parser

The spectre_v2 option 'auto' does not check whether CONFIG_RETPOLINE is
enabled. As a consequence it fails to emit the appropriate warning and sets
feature flags which have no effect at all.

Add the missing IS_ENABLED() check.

Fixes: da285121560e ("x86/spectre: Add boot time option to select Spectre v2 mitigation")
Signed-off-by: Dou Liyang <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: Tomohiro" <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 3bfb2b23d79c5a80113d8c2d89b09dc187de6da2..400c34ec9179af7e1c6b5fbd8581e9b430028096 100644 (file)
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -213,10 +213,10 @@ static void __init spectre_v2_select_mitigation(void)
                return;
 
        case SPECTRE_V2_CMD_FORCE:
-               /* FALLTRHU */
        case SPECTRE_V2_CMD_AUTO:
-               goto retpoline_auto;
-
+               if (IS_ENABLED(CONFIG_RETPOLINE))
+                       goto retpoline_auto;
+               break;
        case SPECTRE_V2_CMD_RETPOLINE_AMD:
                if (IS_ENABLED(CONFIG_RETPOLINE))
                        goto retpoline_amd;