From 1a4e40be95e3ba160f434be4fdc41ef53c7b3afc Mon Sep 17 00:00:00 2001 From: Andy Whitcroft Date: Fri, 26 Jan 2018 12:37:07 +0000 Subject: [PATCH 28/89] Revert "x86/idle: Disable IBRS when offlining cpu and re-enable on wakeup" CVE-2017-5753 (revert embargoed) CVE-2017-5715 (revert embargoed) This reverts commit 9bcf662c1690880b2464fe99d0f58dce53c0d89f. Signed-off-by: Andy Whitcroft --- arch/x86/kernel/smpboot.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index a652bff7add4..398e8324fea4 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -77,7 +77,6 @@ #include #include #include -#include /* Number of siblings per CPU package */ int smp_num_siblings = 1; @@ -1693,15 +1692,9 @@ void native_play_dead(void) play_dead_common(); tboot_shutdown(TB_SHUTDOWN_WFS); - if (boot_cpu_has(X86_FEATURE_SPEC_CTRL)) - native_wrmsrl(MSR_IA32_SPEC_CTRL, 0); - mwait_play_dead(); /* Only returns on failure */ if (cpuidle_play_dead()) hlt_play_dead(); - - if (boot_cpu_has(X86_FEATURE_SPEC_CTRL)) - native_wrmsrl(MSR_IA32_SPEC_CTRL, FEATURE_ENABLE_IBRS); } #else /* ... !CONFIG_HOTPLUG_CPU */ -- 2.15.1