patches/kernel/0279-x86-mm-Set-IBPB-upon-context-switch.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Tim Chen <tim.c.chen@linux.intel.com>
   3 Date: Fri, 20 Oct 2017 12:56:29 -0700
   4 Subject: [PATCH] x86/mm: Set IBPB upon context switch
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 CVE-2017-5753
  10 CVE-2017-5715
  11
  12 Set IBPB on context switch with changing of page table.
  13
  14 Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
  15 Signed-off-by: Andy Whitcroft <apw@canonical.com>
  16 Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
  17 (cherry picked from commit a3320203792b633fb96df5d0bbfb7036129b78e2)
  18 Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
  19 ---
  20  arch/x86/mm/tlb.c | 4 ++++
  21  1 file changed, 4 insertions(+)
  22
  23 diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
  24 index 06f3854d0a4f..bb3ded3a4e5f 100644
  25 --- a/arch/x86/mm/tlb.c
  26 +++ b/arch/x86/mm/tlb.c
  27 @@ -12,6 +12,7 @@
  28  #include <asm/cache.h>
  29  #include <asm/apic.h>
  30  #include <asm/uv/uv.h>
  31 +#include <asm/microcode.h>
  32  #include <linux/debugfs.h>
  33
  34  /*
  35 @@ -218,6 +219,9 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
  36                 u16 new_asid;
  37                 bool need_flush;
  38
  39 +               if (boot_cpu_has(X86_FEATURE_SPEC_CTRL))
  40 +                       native_wrmsrl(MSR_IA32_PRED_CMD, FEATURE_SET_IBPB);
  41 +
  42                 if (IS_ENABLED(CONFIG_VMAP_STACK)) {
  43                         /*
  44                          * If our current stack is in vmalloc space and isn't
  45 --
  46 2.14.2
  47