[patch V181 22/54] x86/cpu_entry_area: Move it out of fixmap

From: Thomas Gleixner
Date: Wed Dec 20 2017 - 17:07:40 EST

Put the cpu_entry_area into a separate p4d entry. The fixmap gets too bug
and 0-day already hit a case where the fixmap ptes were cleared by
cleanup_highmap().

Aside of that the fixmap API is a pain as it's all backwards.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
Documentation/x86/x86_64/mm.txt | 2 +
arch/x86/include/asm/cpu_entry_area.h | 24 ++++++++++++-
arch/x86/include/asm/desc.h | 1
arch/x86/include/asm/fixmap.h | 32 -----------------
arch/x86/include/asm/pgtable_32_types.h | 15 ++++++--
arch/x86/include/asm/pgtable_64_types.h | 47 +++++++++++++++-----------
arch/x86/kernel/dumpstack.c | 1
arch/x86/kernel/traps.c | 5 +-
arch/x86/mm/cpu_entry_area.c | 57 +++++++++++++++++++++++---------
arch/x86/mm/dump_pagetables.c | 6 ++-
arch/x86/mm/init_32.c | 6 +++
arch/x86/mm/kasan_init_64.c | 6 ++-
arch/x86/mm/pgtable_32.c | 1
arch/x86/xen/mmu_pv.c | 2 -
14 files changed, 128 insertions(+), 77 deletions(-)

--- a/Documentation/x86/x86_64/mm.txt
+++ b/Documentation/x86/x86_64/mm.txt
@@ -12,6 +12,7 @@ ffffea0000000000 - ffffeaffffffffff (=40
... unused hole ...
ffffec0000000000 - fffffbffffffffff (=44 bits) kasan shadow memory (16TB)
... unused hole ...
+fffffe8000000000 - fffffeffffffffff (=39 bits) cpu_entry_area mapping
ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks
... unused hole ...
ffffffef00000000 - fffffffeffffffff (=64 GB) EFI region mapping space
@@ -35,6 +36,7 @@ ffd4000000000000 - ffd5ffffffffffff (=49
... unused hole ...
ffdf000000000000 - fffffc0000000000 (=53 bits) kasan shadow memory (8PB)
... unused hole ...
+fffffe8000000000 - fffffeffffffffff (=39 bits) cpu_entry_area mapping
ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks
... unused hole ...
ffffffef00000000 - fffffffeffffffff (=64 GB) EFI region mapping space
--- a/arch/x86/include/asm/cpu_entry_area.h
+++ b/arch/x86/include/asm/cpu_entry_area.h
@@ -43,10 +43,32 @@ struct cpu_entry_area {
};

#define CPU_ENTRY_AREA_SIZE (sizeof(struct cpu_entry_area))
-#define CPU_ENTRY_AREA_PAGES (CPU_ENTRY_AREA_SIZE / PAGE_SIZE)
+#define CPU_ENTRY_AREA_TOT_SIZE (CPU_ENTRY_AREA_SIZE * NR_CPUS)

DECLARE_PER_CPU(struct cpu_entry_area *, cpu_entry_area);

extern void setup_cpu_entry_areas(void);
+extern void cea_set_pte(void *cea_vaddr, phys_addr_t pa, pgprot_t flags);
+
+#define CPU_ENTRY_AREA_RO_IDT CPU_ENTRY_AREA_BASE
+#define CPU_ENTRY_AREA_PER_CPU (CPU_ENTRY_AREA_RO_IDT + PAGE_SIZE)
+
+#define CPU_ENTRY_AREA_RO_IDT_VADDR ((void *)CPU_ENTRY_AREA_RO_IDT)
+
+#define CPU_ENTRY_AREA_MAP_SIZE \
+ (CPU_ENTRY_AREA_PER_CPU + CPU_ENTRY_AREA_TOT_SIZE - CPU_ENTRY_AREA_BASE)
+
+static inline struct cpu_entry_area *get_cpu_entry_area(int cpu)
+{
+ unsigned long va = CPU_ENTRY_AREA_PER_CPU + cpu * CPU_ENTRY_AREA_SIZE;
+ BUILD_BUG_ON(sizeof(struct cpu_entry_area) % PAGE_SIZE != 0);
+
+ return (struct cpu_entry_area *) va;
+}
+
+static inline struct entry_stack *cpu_entry_stack(int cpu)
+{
+ return &get_cpu_entry_area(cpu)->entry_stack_page.stack;
+}

#endif
--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -7,6 +7,7 @@
#include <asm/mmu.h>
#include <asm/fixmap.h>
#include <asm/irq_vectors.h>
+#include <asm/cpu_entry_area.h>

#include <linux/smp.h>
#include <linux/percpu.h>
--- a/arch/x86/include/asm/fixmap.h
+++ b/arch/x86/include/asm/fixmap.h
@@ -25,7 +25,6 @@
#else
#include <uapi/asm/vsyscall.h>
#endif
-#include <asm/cpu_entry_area.h>

/*
* We can't declare FIXADDR_TOP as variable for x86_64 because vsyscall
@@ -84,7 +83,6 @@ enum fixed_addresses {
FIX_IO_APIC_BASE_0,
FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
#endif
- FIX_RO_IDT, /* Virtual mapping for read-only IDT */
#ifdef CONFIG_X86_32
FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
@@ -100,9 +98,6 @@ enum fixed_addresses {
#ifdef CONFIG_X86_INTEL_MID
FIX_LNW_VRTC,
#endif
- /* Fixmap entries to remap the GDTs, one per processor. */
- FIX_CPU_ENTRY_AREA_TOP,
- FIX_CPU_ENTRY_AREA_BOTTOM = FIX_CPU_ENTRY_AREA_TOP + (CPU_ENTRY_AREA_PAGES * NR_CPUS) - 1,

#ifdef CONFIG_ACPI_APEI_GHES
/* Used for GHES mapping from assorted contexts */
@@ -143,7 +138,7 @@ enum fixed_addresses {
extern void reserve_top_address(unsigned long reserve);

#define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
-#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
+#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)

extern int fixmaps_set;

@@ -191,30 +186,5 @@ void __init *early_memremap_decrypted_wp
void __early_set_fixmap(enum fixed_addresses idx,
phys_addr_t phys, pgprot_t flags);

-static inline unsigned int __get_cpu_entry_area_page_index(int cpu, int page)
-{
- BUILD_BUG_ON(sizeof(struct cpu_entry_area) % PAGE_SIZE != 0);
-
- return FIX_CPU_ENTRY_AREA_BOTTOM - cpu*CPU_ENTRY_AREA_PAGES - page;
-}
-
-#define __get_cpu_entry_area_offset_index(cpu, offset) ({ \
- BUILD_BUG_ON(offset % PAGE_SIZE != 0); \
- __get_cpu_entry_area_page_index(cpu, offset / PAGE_SIZE); \
- })
-
-#define get_cpu_entry_area_index(cpu, field) \
- __get_cpu_entry_area_offset_index((cpu), offsetof(struct cpu_entry_area, field))
-
-static inline struct cpu_entry_area *get_cpu_entry_area(int cpu)
-{
- return (struct cpu_entry_area *)__fix_to_virt(__get_cpu_entry_area_page_index(cpu, 0));
-}
-
-static inline struct entry_stack *cpu_entry_stack(int cpu)
-{
- return &get_cpu_entry_area(cpu)->entry_stack_page.stack;
-}
-
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_X86_FIXMAP_H */
--- a/arch/x86/include/asm/pgtable_32_types.h
+++ b/arch/x86/include/asm/pgtable_32_types.h
@@ -38,13 +38,22 @@ extern bool __vmalloc_start_set; /* set
#define LAST_PKMAP 1024
#endif

-#define PKMAP_BASE ((FIXADDR_START - PAGE_SIZE * (LAST_PKMAP + 1)) \
- & PMD_MASK)
+/*
+ * Define this here and validate with BUILD_BUG_ON() in pgtable_32.c
+ * to avoid include recursion hell
+ */
+#define CPU_ENTRY_AREA_PAGES (NR_CPUS * 40)
+
+#define CPU_ENTRY_AREA_BASE \
+ ((FIXADDR_START - PAGE_SIZE * (CPU_ENTRY_AREA_PAGES + 1)) & PMD_MASK)
+
+#define PKMAP_BASE \
+ ((CPU_ENTRY_AREA_BASE - PAGE_SIZE) & PMD_MASK)

#ifdef CONFIG_HIGHMEM
# define VMALLOC_END (PKMAP_BASE - 2 * PAGE_SIZE)
#else
-# define VMALLOC_END (FIXADDR_START - 2 * PAGE_SIZE)
+# define VMALLOC_END (CPU_ENTRY_AREA_BASE - 2 * PAGE_SIZE)
#endif

#define MODULES_VADDR VMALLOC_START
--- a/arch/x86/include/asm/pgtable_64_types.h
+++ b/arch/x86/include/asm/pgtable_64_types.h
@@ -76,32 +76,41 @@ typedef struct { pteval_t pte; } pte_t;
#define PGDIR_MASK (~(PGDIR_SIZE - 1))

/* See Documentation/x86/x86_64/mm.txt for a description of the memory map. */
-#define MAXMEM _AC(__AC(1, UL) << MAX_PHYSMEM_BITS, UL)
+#define MAXMEM _AC(__AC(1, UL) << MAX_PHYSMEM_BITS, UL)
+
#ifdef CONFIG_X86_5LEVEL
-#define VMALLOC_SIZE_TB _AC(16384, UL)
-#define __VMALLOC_BASE _AC(0xff92000000000000, UL)
-#define __VMEMMAP_BASE _AC(0xffd4000000000000, UL)
+# define VMALLOC_SIZE_TB _AC(16384, UL)
+# define __VMALLOC_BASE _AC(0xff92000000000000, UL)
+# define __VMEMMAP_BASE _AC(0xffd4000000000000, UL)
#else
-#define VMALLOC_SIZE_TB _AC(32, UL)
-#define __VMALLOC_BASE _AC(0xffffc90000000000, UL)
-#define __VMEMMAP_BASE _AC(0xffffea0000000000, UL)
+# define VMALLOC_SIZE_TB _AC(32, UL)
+# define __VMALLOC_BASE _AC(0xffffc90000000000, UL)
+# define __VMEMMAP_BASE _AC(0xffffea0000000000, UL)
#endif
+
#ifdef CONFIG_RANDOMIZE_MEMORY
-#define VMALLOC_START vmalloc_base
-#define VMEMMAP_START vmemmap_base
+# define VMALLOC_START vmalloc_base
+# define VMEMMAP_START vmemmap_base
#else
-#define VMALLOC_START __VMALLOC_BASE
-#define VMEMMAP_START __VMEMMAP_BASE
+# define VMALLOC_START __VMALLOC_BASE
+# define VMEMMAP_START __VMEMMAP_BASE
#endif /* CONFIG_RANDOMIZE_MEMORY */
-#define VMALLOC_END (VMALLOC_START + _AC((VMALLOC_SIZE_TB << 40) - 1, UL))
-#define MODULES_VADDR (__START_KERNEL_map + KERNEL_IMAGE_SIZE)
+
+#define VMALLOC_END (VMALLOC_START + _AC((VMALLOC_SIZE_TB << 40) - 1, UL))
+
+#define MODULES_VADDR (__START_KERNEL_map + KERNEL_IMAGE_SIZE)
/* The module sections ends with the start of the fixmap */
-#define MODULES_END __fix_to_virt(__end_of_fixed_addresses + 1)
-#define MODULES_LEN (MODULES_END - MODULES_VADDR)
-#define ESPFIX_PGD_ENTRY _AC(-2, UL)
-#define ESPFIX_BASE_ADDR (ESPFIX_PGD_ENTRY << P4D_SHIFT)
-#define EFI_VA_START ( -4 * (_AC(1, UL) << 30))
-#define EFI_VA_END (-68 * (_AC(1, UL) << 30))
+#define MODULES_END __fix_to_virt(__end_of_fixed_addresses + 1)
+#define MODULES_LEN (MODULES_END - MODULES_VADDR)
+
+#define ESPFIX_PGD_ENTRY _AC(-2, UL)
+#define ESPFIX_BASE_ADDR (ESPFIX_PGD_ENTRY << P4D_SHIFT)
+
+#define CPU_ENTRY_AREA_PGD _AC(-3, UL)
+#define CPU_ENTRY_AREA_BASE (CPU_ENTRY_AREA_PGD << P4D_SHIFT)
+
+#define EFI_VA_START ( -4 * (_AC(1, UL) << 30))
+#define EFI_VA_END (-68 * (_AC(1, UL) << 30))

#define EARLY_DYNAMIC_PAGE_TABLES 64

--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -18,6 +18,7 @@
#include <linux/nmi.h>
#include <linux/sysfs.h>

+#include <asm/cpu_entry_area.h>
#include <asm/stacktrace.h>
#include <asm/unwind.h>

--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -951,8 +951,9 @@ void __init trap_init(void)
* "sidt" instruction will not leak the location of the kernel, and
* to defend the IDT against arbitrary memory write vulnerabilities.
* It will be reloaded in cpu_init() */
- __set_fixmap(FIX_RO_IDT, __pa_symbol(idt_table), PAGE_KERNEL_RO);
- idt_descr.address = fix_to_virt(FIX_RO_IDT);
+ cea_set_pte(CPU_ENTRY_AREA_RO_IDT_VADDR, __pa_symbol(idt_table),
+ PAGE_KERNEL_RO);
+ idt_descr.address = CPU_ENTRY_AREA_RO_IDT;

/*
* Should be a barrier for any external CPU state:
--- a/arch/x86/mm/cpu_entry_area.c
+++ b/arch/x86/mm/cpu_entry_area.c
@@ -13,11 +13,18 @@ static DEFINE_PER_CPU_PAGE_ALIGNED(char,
[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]);
#endif

+void cea_set_pte(void *cea_vaddr, phys_addr_t pa, pgprot_t flags)
+{
+ unsigned long va = (unsigned long) cea_vaddr;
+
+ set_pte_vaddr(va, pfn_pte(pa >> PAGE_SHIFT, flags));
+}
+
static void __init
-set_percpu_fixmap_pages(int idx, void *ptr, int pages, pgprot_t prot)
+cea_map_percpu_pages(void *cea_vaddr, void *ptr, int pages, pgprot_t prot)
{
- for ( ; pages; pages--, idx--, ptr += PAGE_SIZE)
- __set_fixmap(idx, per_cpu_ptr_to_phys(ptr), prot);
+ for ( ; pages; pages--, cea_vaddr+= PAGE_SIZE, ptr += PAGE_SIZE)
+ cea_set_pte(cea_vaddr, per_cpu_ptr_to_phys(ptr), prot);
}

/* Setup the fixmap mappings only once per-processor */
@@ -45,10 +52,12 @@ static void __init setup_cpu_entry_area(
pgprot_t tss_prot = PAGE_KERNEL;
#endif

- __set_fixmap(get_cpu_entry_area_index(cpu, gdt), get_cpu_gdt_paddr(cpu), gdt_prot);
- set_percpu_fixmap_pages(get_cpu_entry_area_index(cpu, entry_stack_page),
- per_cpu_ptr(&entry_stack_storage, cpu), 1,
- PAGE_KERNEL);
+ cea_set_pte(&get_cpu_entry_area(cpu)->gdt, get_cpu_gdt_paddr(cpu),
+ gdt_prot);
+
+ cea_map_percpu_pages(&get_cpu_entry_area(cpu)->entry_stack_page,
+ per_cpu_ptr(&entry_stack_storage, cpu), 1,
+ PAGE_KERNEL);

/*
* The Intel SDM says (Volume 3, 7.2.1):
@@ -70,10 +79,9 @@ static void __init setup_cpu_entry_area(
BUILD_BUG_ON((offsetof(struct tss_struct, x86_tss) ^
offsetofend(struct tss_struct, x86_tss)) & PAGE_MASK);
BUILD_BUG_ON(sizeof(struct tss_struct) % PAGE_SIZE != 0);
- set_percpu_fixmap_pages(get_cpu_entry_area_index(cpu, tss),
- &per_cpu(cpu_tss_rw, cpu),
- sizeof(struct tss_struct) / PAGE_SIZE,
- tss_prot);
+ cea_map_percpu_pages(&get_cpu_entry_area(cpu)->tss,
+ &per_cpu(cpu_tss_rw, cpu),
+ sizeof(struct tss_struct) / PAGE_SIZE, tss_prot);

#ifdef CONFIG_X86_32
per_cpu(cpu_entry_area, cpu) = get_cpu_entry_area(cpu);
@@ -83,20 +91,37 @@ static void __init setup_cpu_entry_area(
BUILD_BUG_ON(sizeof(exception_stacks) % PAGE_SIZE != 0);
BUILD_BUG_ON(sizeof(exception_stacks) !=
sizeof(((struct cpu_entry_area *)0)->exception_stacks));
- set_percpu_fixmap_pages(get_cpu_entry_area_index(cpu, exception_stacks),
- &per_cpu(exception_stacks, cpu),
- sizeof(exception_stacks) / PAGE_SIZE,
- PAGE_KERNEL);
+ cea_map_percpu_pages(&get_cpu_entry_area(cpu)->exception_stacks,
+ &per_cpu(exception_stacks, cpu),
+ sizeof(exception_stacks) / PAGE_SIZE, PAGE_KERNEL);

- __set_fixmap(get_cpu_entry_area_index(cpu, entry_trampoline),
+ cea_set_pte(&get_cpu_entry_area(cpu)->entry_trampoline,
__pa_symbol(_entry_trampoline), PAGE_KERNEL_RX);
#endif
}

+static __init void setup_cpu_entry_area_ptes(void)
+{
+#ifdef CONFIG_X86_32
+ unsigned long start, end;
+
+ BUILD_BUG_ON(CPU_ENTRY_AREA_PAGES * PAGE_SIZE < CPU_ENTRY_AREA_MAP_SIZE);
+ BUG_ON(CPU_ENTRY_AREA_BASE & ~PMD_MASK);
+
+ start = CPU_ENTRY_AREA_BASE;
+ end = start + CPU_ENTRY_AREA_MAP_SIZE;
+
+ for (; start < end; start += PMD_SIZE)
+ populate_extra_pte(start);
+#endif
+}
+
void __init setup_cpu_entry_areas(void)
{
unsigned int cpu;

+ setup_cpu_entry_area_ptes();
+
for_each_possible_cpu(cpu)
setup_cpu_entry_area(cpu);
}
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -58,6 +58,7 @@ enum address_markers_idx {
KASAN_SHADOW_START_NR,
KASAN_SHADOW_END_NR,
#endif
+ CPU_ENTRY_AREA_NR,
#ifdef CONFIG_X86_ESPFIX64
ESPFIX_START_NR,
#endif
@@ -81,6 +82,7 @@ static struct addr_marker address_marker
[KASAN_SHADOW_START_NR] = { KASAN_SHADOW_START, "KASAN shadow" },
[KASAN_SHADOW_END_NR] = { KASAN_SHADOW_END, "KASAN shadow end" },
#endif
+ [CPU_ENTRY_AREA_NR] = { CPU_ENTRY_AREA_BASE,"CPU entry Area" },
#ifdef CONFIG_X86_ESPFIX64
[ESPFIX_START_NR] = { ESPFIX_BASE_ADDR, "ESPfix Area", 16 },
#endif
@@ -104,6 +106,7 @@ enum address_markers_idx {
#ifdef CONFIG_HIGHMEM
PKMAP_BASE_NR,
#endif
+ CPU_ENTRY_AREA_NR,
FIXADDR_START_NR,
END_OF_SPACE_NR,
};
@@ -116,6 +119,7 @@ static struct addr_marker address_marker
#ifdef CONFIG_HIGHMEM
[PKMAP_BASE_NR] = { 0UL, "Persistent kmap() Area" },
#endif
+ [CPU_ENTRY_AREA_NR] = { 0UL, "CPU entry area" },
[FIXADDR_START_NR] = { 0UL, "Fixmap area" },
[END_OF_SPACE_NR] = { -1, NULL }
};
@@ -541,8 +545,8 @@ static int __init pt_dump_init(void)
address_markers[PKMAP_BASE_NR].start_address = PKMAP_BASE;
# endif
address_markers[FIXADDR_START_NR].start_address = FIXADDR_START;
+ address_markers[CPU_ENTRY_AREA_NR].start_address = CPU_ENTRY_AREA_BASE;
#endif
-
return 0;
}
__initcall(pt_dump_init);
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -50,6 +50,7 @@
#include <asm/setup.h>
#include <asm/set_memory.h>
#include <asm/page_types.h>
+#include <asm/cpu_entry_area.h>
#include <asm/init.h>

#include "mm_internal.h"
@@ -766,6 +767,7 @@ void __init mem_init(void)
mem_init_print_info(NULL);
printk(KERN_INFO "virtual kernel memory layout:\n"
" fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
+ " cpu_entry : 0x%08lx - 0x%08lx (%4ld kB)\n"
#ifdef CONFIG_HIGHMEM
" pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
#endif
@@ -777,6 +779,10 @@ void __init mem_init(void)
FIXADDR_START, FIXADDR_TOP,
(FIXADDR_TOP - FIXADDR_START) >> 10,

+ CPU_ENTRY_AREA_BASE,
+ CPU_ENTRY_AREA_BASE + CPU_ENTRY_AREA_MAP_SIZE,
+ CPU_ENTRY_AREA_MAP_SIZE >> 10,
+
#ifdef CONFIG_HIGHMEM
PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
(LAST_PKMAP*PAGE_SIZE) >> 10,
--- a/arch/x86/mm/kasan_init_64.c
+++ b/arch/x86/mm/kasan_init_64.c
@@ -15,6 +15,7 @@
#include <asm/tlbflush.h>
#include <asm/sections.h>
#include <asm/pgtable.h>
+#include <asm/cpu_entry_area.h>

extern struct range pfn_mapped[E820_MAX_ENTRIES];

@@ -330,12 +331,13 @@ void __init kasan_init(void)
(unsigned long)kasan_mem_to_shadow(_end),
early_pfn_to_nid(__pa(_stext)));

- shadow_cpu_entry_begin = (void *)__fix_to_virt(FIX_CPU_ENTRY_AREA_BOTTOM);
+ shadow_cpu_entry_begin = (void *)CPU_ENTRY_AREA_BASE;
shadow_cpu_entry_begin = kasan_mem_to_shadow(shadow_cpu_entry_begin);
shadow_cpu_entry_begin = (void *)round_down((unsigned long)shadow_cpu_entry_begin,
PAGE_SIZE);

- shadow_cpu_entry_end = (void *)(__fix_to_virt(FIX_CPU_ENTRY_AREA_TOP) + PAGE_SIZE);
+ shadow_cpu_entry_end = (void *)(CPU_ENTRY_AREA_BASE +
+ CPU_ENTRY_AREA_TOT_SIZE);
shadow_cpu_entry_end = kasan_mem_to_shadow(shadow_cpu_entry_end);
shadow_cpu_entry_end = (void *)round_up((unsigned long)shadow_cpu_entry_end,
PAGE_SIZE);
--- a/arch/x86/mm/pgtable_32.c
+++ b/arch/x86/mm/pgtable_32.c
@@ -10,6 +10,7 @@
#include <linux/pagemap.h>
#include <linux/spinlock.h>

+#include <asm/cpu_entry_area.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/fixmap.h>
--- a/arch/x86/xen/mmu_pv.c
+++ b/arch/x86/xen/mmu_pv.c
@@ -2261,7 +2261,6 @@ static void xen_set_fixmap(unsigned idx,

switch (idx) {
case FIX_BTMAP_END ... FIX_BTMAP_BEGIN:
- case FIX_RO_IDT:
#ifdef CONFIG_X86_32
case FIX_WP_TEST:
# ifdef CONFIG_HIGHMEM
@@ -2272,7 +2271,6 @@ static void xen_set_fixmap(unsigned idx,
#endif
case FIX_TEXT_POKE0:
case FIX_TEXT_POKE1:
- case FIX_CPU_ENTRY_AREA_TOP ... FIX_CPU_ENTRY_AREA_BOTTOM:
/* All local page mappings */
pte = pfn_pte(phys, prot);
break;