From: Dou Liyang <douly.fnst@cn.fujitsu.com>
Date: Tue, 30 Jan 2018 14:13:50 +0800
Subject: x86/spectre: Check CONFIG_RETPOLINE in command line parser
Git-commit: 9471eee9186a46893726e22ebb54cade3f9bc043
Patch-mainline: v4.16-rc1
References: bnc#1068032 bnc#1085823 CVE-2017-5715
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 <douly.fnst@cn.fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ak@linux.intel.com
Cc: peterz@infradead.org
Cc: Tomohiro" <misono.tomohiro@jp.fujitsu.com>
Cc: dave.hansen@intel.com
Cc: bp@alien8.de
Cc: arjan@linux.intel.com
Cc: dwmw@amazon.co.uk
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/f5892721-7528-3647-08fb-f8d10e65ad87@cn.fujitsu.com
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
arch/x86/kernel/cpu/bugs.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -212,10 +212,10 @@ static void __init spectre_v2_select_mit
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;