| From foo@baz Thu Feb 8 03:30:27 CET 2018 |
| 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 |
| |
| From: Dou Liyang <douly.fnst@cn.fujitsu.com> |
| |
| (cherry picked from commit 9471eee9186a46893726e22ebb54cade3f9bc043) |
| |
| 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: David Woodhouse <dwmw@amazon.co.uk> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| 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; |