4.9-stable review patch. If anyone has any objections, please let me know.
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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.co... 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;