Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86/pti fixes from Thomas Gleixner:
 "Three fixes related to melted spectrum:

   - Sync the cpu_entry_area page table to initial_page_table on 32 bit.

     Otherwise suspend/resume fails because resume uses
     initial_page_table and triggers a triple fault when accessing the
     cpu entry area.

   - Zero the SPEC_CTL MRS on XEN before suspend to address a
     shortcoming in the hypervisor.

   - Fix another switch table detection issue in objtool"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu_entry_area: Sync cpu_entry_area to initial_page_table
  objtool: Fix another switch table detection issue
  x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend
This commit is contained in:
Linus Torvalds
2018-03-04 11:40:16 -08:00
8 changed files with 53 additions and 26 deletions

View File

@@ -1,12 +1,15 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/types.h>
#include <linux/tick.h>
#include <linux/percpu-defs.h>
#include <xen/xen.h>
#include <xen/interface/xen.h>
#include <xen/grant_table.h>
#include <xen/events.h>
#include <asm/cpufeatures.h>
#include <asm/msr-index.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/page.h>
#include <asm/fixmap.h>
@@ -15,6 +18,8 @@
#include "mmu.h"
#include "pmu.h"
static DEFINE_PER_CPU(u64, spec_ctrl);
void xen_arch_pre_suspend(void)
{
xen_save_time_memory_area();
@@ -35,6 +40,9 @@ void xen_arch_post_suspend(int cancelled)
static void xen_vcpu_notify_restore(void *data)
{
if (xen_pv_domain() && boot_cpu_has(X86_FEATURE_SPEC_CTRL))
wrmsrl(MSR_IA32_SPEC_CTRL, this_cpu_read(spec_ctrl));
/* Boot processor notified via generic timekeeping_resume() */
if (smp_processor_id() == 0)
return;
@@ -44,7 +52,15 @@ static void xen_vcpu_notify_restore(void *data)
static void xen_vcpu_notify_suspend(void *data)
{
u64 tmp;
tick_suspend_local();
if (xen_pv_domain() && boot_cpu_has(X86_FEATURE_SPEC_CTRL)) {
rdmsrl(MSR_IA32_SPEC_CTRL, tmp);
this_cpu_write(spec_ctrl, tmp);
wrmsrl(MSR_IA32_SPEC_CTRL, 0);
}
}
void xen_arch_resume(void)