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authorLinus Torvalds <torvalds@linux-foundation.org>2018-03-04 11:40:16 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-03-04 11:40:16 -0800
commit7225a442788e20ee108ef2cb97d511375e20acf9 (patch)
tree98b2ecf1b606bd843356a8df7826a2e1c78d1eca /arch/x86
parent4c4ce3022dc7352d05de4d8e1602c9a2a14458bf (diff)
parent945fd17ab6bab8a4d05da6c3170519fbcfe62ddb (diff)
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
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/include/asm/pgtable_32.h1
-rw-r--r--arch/x86/include/asm/pgtable_64.h1
-rw-r--r--arch/x86/kernel/setup.c17
-rw-r--r--arch/x86/kernel/setup_percpu.c17
-rw-r--r--arch/x86/mm/cpu_entry_area.c6
-rw-r--r--arch/x86/mm/init_32.c15
-rw-r--r--arch/x86/xen/suspend.c16
7 files changed, 48 insertions, 25 deletions
diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h
index e55466760ff8..b3ec519e3982 100644
--- a/arch/x86/include/asm/pgtable_32.h
+++ b/arch/x86/include/asm/pgtable_32.h
@@ -32,6 +32,7 @@ extern pmd_t initial_pg_pmd[];
static inline void pgtable_cache_init(void) { }
static inline void check_pgt_cache(void) { }
void paging_init(void);
+void sync_initial_page_table(void);
/*
* Define this if things work differently on an i386 and an i486:
diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index 81462e9a34f6..1149d2112b2e 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -28,6 +28,7 @@ extern pgd_t init_top_pgt[];
#define swapper_pg_dir init_top_pgt
extern void paging_init(void);
+static inline void sync_initial_page_table(void) { }
#define pte_ERROR(e) \
pr_err("%s:%d: bad pte %p(%016lx)\n", \
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 1ae67e982af7..4c616be28506 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1204,20 +1204,13 @@ void __init setup_arch(char **cmdline_p)
kasan_init();
-#ifdef CONFIG_X86_32
- /* sync back kernel address range */
- clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY,
- swapper_pg_dir + KERNEL_PGD_BOUNDARY,
- KERNEL_PGD_PTRS);
-
/*
- * sync back low identity map too. It is used for example
- * in the 32-bit EFI stub.
+ * Sync back kernel address range.
+ *
+ * FIXME: Can the later sync in setup_cpu_entry_areas() replace
+ * this call?
*/
- clone_pgd_range(initial_page_table,
- swapper_pg_dir + KERNEL_PGD_BOUNDARY,
- min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
-#endif
+ sync_initial_page_table();
tboot_probe();
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index 497aa766fab3..ea554f812ee1 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -287,24 +287,15 @@ void __init setup_per_cpu_areas(void)
/* Setup cpu initialized, callin, callout masks */
setup_cpu_local_masks();
-#ifdef CONFIG_X86_32
/*
* Sync back kernel address range again. We already did this in
* setup_arch(), but percpu data also needs to be available in
* the smpboot asm. We can't reliably pick up percpu mappings
* using vmalloc_fault(), because exception dispatch needs
* percpu data.
+ *
+ * FIXME: Can the later sync in setup_cpu_entry_areas() replace
+ * this call?
*/
- clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY,
- swapper_pg_dir + KERNEL_PGD_BOUNDARY,
- KERNEL_PGD_PTRS);
-
- /*
- * sync back low identity map too. It is used for example
- * in the 32-bit EFI stub.
- */
- clone_pgd_range(initial_page_table,
- swapper_pg_dir + KERNEL_PGD_BOUNDARY,
- min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
-#endif
+ sync_initial_page_table();
}
diff --git a/arch/x86/mm/cpu_entry_area.c b/arch/x86/mm/cpu_entry_area.c
index b9283cc27622..476d810639a8 100644
--- a/arch/x86/mm/cpu_entry_area.c
+++ b/arch/x86/mm/cpu_entry_area.c
@@ -163,4 +163,10 @@ void __init setup_cpu_entry_areas(void)
for_each_possible_cpu(cpu)
setup_cpu_entry_area(cpu);
+
+ /*
+ * This is the last essential update to swapper_pgdir which needs
+ * to be synchronized to initial_page_table on 32bit.
+ */
+ sync_initial_page_table();
}
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 79cb066f40c0..396e1f0151ac 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -453,6 +453,21 @@ static inline void permanent_kmaps_init(pgd_t *pgd_base)
}
#endif /* CONFIG_HIGHMEM */
+void __init sync_initial_page_table(void)
+{
+ clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY,
+ swapper_pg_dir + KERNEL_PGD_BOUNDARY,
+ KERNEL_PGD_PTRS);
+
+ /*
+ * sync back low identity map too. It is used for example
+ * in the 32-bit EFI stub.
+ */
+ clone_pgd_range(initial_page_table,
+ swapper_pg_dir + KERNEL_PGD_BOUNDARY,
+ min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
+}
+
void __init native_pagetable_init(void)
{
unsigned long pfn, va;
diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c
index d9f96cc5d743..1d83152c761b 100644
--- a/arch/x86/xen/suspend.c
+++ b/arch/x86/xen/suspend.c
@@ -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)