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

Browse Source 
Pull x86 mm updates from Ingo Molnar:
 "The main changes in this cycle were:

   - Continued work to add support for 5-level paging provided by future
     Intel CPUs. In particular we switch the x86 GUP code to the generic
     implementation. (Kirill A. Shutemov)

   - Continued work to add PCID CPU support to native kernels as well.
     In this round most of the focus is on reworking/refreshing the TLB
     flush infrastructure for the upcoming PCID changes. (Andy
     Lutomirski)"

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits)
  x86/mm: Delete a big outdated comment about TLB flushing
  x86/mm: Don't reenter flush_tlb_func_common()
  x86/KASLR: Fix detection 32/64 bit bootloaders for 5-level paging
  x86/ftrace: Exclude functions in head64.c from function-tracing
  x86/mmap, ASLR: Do not treat unlimited-stack tasks as legacy mmap
  x86/mm: Remove reset_lazy_tlbstate()
  x86/ldt: Simplify the LDT switching logic
  x86/boot/64: Put __startup_64() into .head.text
  x86/mm: Add support for 5-level paging for KASLR
  x86/mm: Make kernel_physical_mapping_init() support 5-level paging
  x86/mm: Add sync_global_pgds() for configuration with 5-level paging
  x86/boot/64: Add support of additional page table level during early boot
  x86/boot/64: Rename init_level4_pgt and early_level4_pgt
  x86/boot/64: Rewrite startup_64() in C
  x86/boot/compressed: Enable 5-level paging during decompression stage
  x86/boot/efi: Define __KERNEL32_CS GDT on 64-bit configurations
  x86/boot/efi: Fix __KERNEL_CS definition of GDT entry on 64-bit configurations
  x86/boot/efi: Cleanup initialization of GDT entries
  x86/asm: Fix comment in return_from_SYSCALL_64()
  x86/mm/gup: Switch GUP to the generic get_user_page_fast() implementation
  ...
This commit is contained in:
Linus Torvalds 2017-07-03 14:45:09 -07:00
commit 7a69f9c60b
62 changed files with 1093 additions and 1230 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/arm/Kconfig
View File

@ -1638,7 +1638,7 @@ config ARCH_SELECT_MEMORY_MODEL
config HAVE_ARCH_PFN_VALID
def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
config HAVE_GENERIC_RCU_GUP
config HAVE_GENERIC_GUP
def_bool y
depends on ARM_LPAE

2
arch/arm64/Kconfig
View File

@ -205,7 +205,7 @@ config GENERIC_CALIBRATE_DELAY
config ZONE_DMA
def_bool y
config HAVE_GENERIC_RCU_GUP
config HAVE_GENERIC_GUP
def_bool y
config ARCH_DMA_ADDR_T_64BIT

2
arch/powerpc/Kconfig
View File

@ -184,7 +184,7 @@ config PPC
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER
select HAVE_GCC_PLUGINS
select HAVE_GENERIC_RCU_GUP
select HAVE_GENERIC_GUP
select HAVE_HW_BREAKPOINT if PERF_EVENTS && (PPC_BOOK3S || PPC_8xx)
select HAVE_IDE
select HAVE_IOREMAP_PROT

5
arch/x86/Kconfig
View File

@ -69,7 +69,7 @@ config X86
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_QUEUED_RWLOCKS
select ARCH_USE_QUEUED_SPINLOCKS
select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
select ARCH_WANT_FRAME_POINTERS
select ARCH_WANTS_DYNAMIC_TASK_STRUCT
select BUILDTIME_EXTABLE_SORT
@ -2793,6 +2793,9 @@ config X86_DMA_REMAP
bool
depends on STA2X11
config HAVE_GENERIC_GUP
def_bool y
source "net/Kconfig"
source "drivers/Kconfig"

73
arch/x86/boot/compressed/eboot.c
View File

@ -1046,9 +1046,31 @@ struct boot_params *efi_main(struct efi_config *c,
memset((char *)gdt->address, 0x0, gdt->size);
desc = (struct desc_struct *)gdt->address;
/* The first GDT is a dummy and the second is unused. */
desc += 2;
/* The first GDT is a dummy. */
desc++;
if (IS_ENABLED(CONFIG_X86_64)) {
/* __KERNEL32_CS */
desc->limit0 = 0xffff;
desc->base0 = 0x0000;
desc->base1 = 0x0000;
desc->type = SEG_TYPE_CODE | SEG_TYPE_EXEC_READ;
desc->s = DESC_TYPE_CODE_DATA;
desc->dpl = 0;
desc->p = 1;
desc->limit = 0xf;
desc->avl = 0;
desc->l = 0;
desc->d = SEG_OP_SIZE_32BIT;
desc->g = SEG_GRANULARITY_4KB;
desc->base2 = 0x00;
desc++;
} else {
/* Second entry is unused on 32-bit */
desc++;
}
/* __KERNEL_CS */
desc->limit0 = 0xffff;
desc->base0 = 0x0000;
desc->base1 = 0x0000;
@ -1058,12 +1080,18 @@ struct boot_params *efi_main(struct efi_config *c,
desc->p = 1;
desc->limit = 0xf;
desc->avl = 0;
desc->l = 0;
desc->d = SEG_OP_SIZE_32BIT;
if (IS_ENABLED(CONFIG_X86_64)) {
desc->l = 1;
desc->d = 0;
} else {
desc->l = 0;
desc->d = SEG_OP_SIZE_32BIT;
}
desc->g = SEG_GRANULARITY_4KB;
desc->base2 = 0x00;
desc++;
/* __KERNEL_DS */
desc->limit0 = 0xffff;
desc->base0 = 0x0000;
desc->base1 = 0x0000;
@ -1077,24 +1105,25 @@ struct boot_params *efi_main(struct efi_config *c,
desc->d = SEG_OP_SIZE_32BIT;
desc->g = SEG_GRANULARITY_4KB;
desc->base2 = 0x00;
#ifdef CONFIG_X86_64
/* Task segment value */
desc++;
desc->limit0 = 0x0000;
desc->base0 = 0x0000;
desc->base1 = 0x0000;
desc->type = SEG_TYPE_TSS;
desc->s = 0;
desc->dpl = 0;
desc->p = 1;
desc->limit = 0x0;
desc->avl = 0;
desc->l = 0;
desc->d = 0;
desc->g = SEG_GRANULARITY_4KB;
desc->base2 = 0x00;
#endif /* CONFIG_X86_64 */
if (IS_ENABLED(CONFIG_X86_64)) {
/* Task segment value */
desc->limit0 = 0x0000;
desc->base0 = 0x0000;
desc->base1 = 0x0000;
desc->type = SEG_TYPE_TSS;
desc->s = 0;
desc->dpl = 0;
desc->p = 1;
desc->limit = 0x0;
desc->avl = 0;
desc->l = 0;
desc->d = 0;
desc->g = SEG_GRANULARITY_4KB;
desc->base2 = 0x00;
desc++;
}
asm volatile("cli");
asm volatile ("lgdt %0" : : "m" (*gdt));

86
arch/x86/boot/compressed/head_64.S
View File

@ -346,6 +346,48 @@ preferred_addr:
/* Set up the stack */
leaq boot_stack_end(%rbx), %rsp
#ifdef CONFIG_X86_5LEVEL
/* Check if 5-level paging has already enabled */
movq %cr4, %rax
testl $X86_CR4_LA57, %eax
jnz lvl5
/*
* At this point we are in long mode with 4-level paging enabled,
* but we want to enable 5-level paging.
*
* The problem is that we cannot do it directly. Setting LA57 in
* long mode would trigger #GP. So we need to switch off long mode
* first.
*
* NOTE: This is not going to work if bootloader put us above 4G
* limit.
*
* The first step is go into compatibility mode.
*/
/* Clear additional page table */
leaq lvl5_pgtable(%rbx), %rdi
xorq %rax, %rax
movq $(PAGE_SIZE/8), %rcx
rep stosq
/*
* Setup current CR3 as the first and only entry in a new top level
* page table.
*/
movq %cr3, %rdi
leaq 0x7 (%rdi), %rax
movq %rax, lvl5_pgtable(%rbx)
/* Switch to compatibility mode (CS.L = 0 CS.D = 1) via far return */
pushq $__KERNEL32_CS
leaq compatible_mode(%rip), %rax
pushq %rax
lretq
lvl5:
#endif
/* Zero EFLAGS */
pushq $0
popfq
@ -429,6 +471,44 @@ relocated:
jmp *%rax
.code32
#ifdef CONFIG_X86_5LEVEL
compatible_mode:
/* Setup data and stack segments */
movl $__KERNEL_DS, %eax
movl %eax, %ds
movl %eax, %ss
/* Disable paging */
movl %cr0, %eax
btrl $X86_CR0_PG_BIT, %eax
movl %eax, %cr0
/* Point CR3 to 5-level paging */
leal lvl5_pgtable(%ebx), %eax
movl %eax, %cr3
/* Enable PAE and LA57 mode */
movl %cr4, %eax
orl $(X86_CR4_PAE | X86_CR4_LA57), %eax
movl %eax, %cr4
/* Calculate address we are running at */
call 1f
1: popl %edi
subl $1b, %edi
/* Prepare stack for far return to Long Mode */
pushl $__KERNEL_CS
leal lvl5(%edi), %eax
push %eax
/* Enable paging back */
movl $(X86_CR0_PG | X86_CR0_PE), %eax
movl %eax, %cr0
lret
#endif
no_longmode:
/* This isn't an x86-64 CPU so hang */
1:
@ -442,7 +522,7 @@ gdt:
.word gdt_end - gdt
.long gdt
.word 0
.quad 0x0000000000000000 /* NULL descriptor */
.quad 0x00cf9a000000ffff /* __KERNEL32_CS */
.quad 0x00af9a000000ffff /* __KERNEL_CS */
.quad 0x00cf92000000ffff /* __KERNEL_DS */
.quad 0x0080890000000000 /* TS descriptor */
@ -486,3 +566,7 @@ boot_stack_end:
.balign 4096
pgtable:
.fill BOOT_PGT_SIZE, 1, 0
#ifdef CONFIG_X86_5LEVEL
lvl5_pgtable:
.fill PAGE_SIZE, 1, 0
#endif

18
arch/x86/boot/compressed/pagetable.c
View File

@ -63,7 +63,7 @@ static void *alloc_pgt_page(void *context)
static struct alloc_pgt_data pgt_data;
/* The top level page table entry pointer. */
static unsigned long level4p;
static unsigned long top_level_pgt;
/*
* Mapping information structure passed to kernel_ident_mapping_init().
@ -91,9 +91,15 @@ void initialize_identity_maps(void)
* If we came here via startup_32(), cr3 will be _pgtable already
* and we must append to the existing area instead of entirely
* overwriting it.
*
* With 5-level paging, we use '_pgtable' to allocate the p4d page table,
* the top-level page table is allocated separately.
*
* p4d_offset(top_level_pgt, 0) would cover both the 4- and 5-level
* cases. On 4-level paging it's equal to 'top_level_pgt'.
*/
level4p = read_cr3();
if (level4p == (unsigned long)_pgtable) {
top_level_pgt = read_cr3_pa();
if (p4d_offset((pgd_t *)top_level_pgt, 0) == (p4d_t *)_pgtable) {
debug_putstr("booted via startup_32()\n");
pgt_data.pgt_buf = _pgtable + BOOT_INIT_PGT_SIZE;
pgt_data.pgt_buf_size = BOOT_PGT_SIZE - BOOT_INIT_PGT_SIZE;
@ -103,7 +109,7 @@ void initialize_identity_maps(void)
pgt_data.pgt_buf = _pgtable;
pgt_data.pgt_buf_size = BOOT_PGT_SIZE;
memset(pgt_data.pgt_buf, 0, pgt_data.pgt_buf_size);
level4p = (unsigned long)alloc_pgt_page(&pgt_data);
top_level_pgt = (unsigned long)alloc_pgt_page(&pgt_data);
}
}
@ -123,7 +129,7 @@ void add_identity_map(unsigned long start, unsigned long size)
return;
/* Build the mapping. */
kernel_ident_mapping_init(&mapping_info, (pgd_t *)level4p,
kernel_ident_mapping_init(&mapping_info, (pgd_t *)top_level_pgt,
start, end);
}
@ -134,5 +140,5 @@ void add_identity_map(unsigned long start, unsigned long size)
*/
void finalize_identity_maps(void)
{
write_cr3(level4p);
write_cr3(top_level_pgt);
}

3
arch/x86/entry/entry_64.S
View File

@ -265,7 +265,8 @@ return_from_SYSCALL_64:
* If width of "canonical tail" ever becomes variable, this will need
* to be updated to remain correct on both old and new CPUs.
*
* Change top 16 bits to be the sign-extension of 47th bit
* Change top bits to match most significant bit (47th or 56th bit
* depending on paging mode) in the address.
*/
shl $(64 - (__VIRTUAL_MASK_SHIFT+1)), %rcx
sar $(64 - (__VIRTUAL_MASK_SHIFT+1)), %rcx

5
arch/x86/events/core.c
View File

@ -2111,8 +2111,7 @@ static int x86_pmu_event_init(struct perf_event *event)
static void refresh_pce(void *ignored)
{
if (current->active_mm)
load_mm_cr4(current->active_mm);
load_mm_cr4(this_cpu_read(cpu_tlbstate.loaded_mm));
}
static void x86_pmu_event_mapped(struct perf_event *event)
@ -2344,7 +2343,7 @@ static unsigned long get_segment_base(unsigned int segment)
/* IRQs are off, so this synchronizes with smp_store_release */
ldt = lockless_dereference(current->active_mm->context.ldt);
if (!ldt || idx > ldt->size)
if (!ldt || idx > ldt->nr_entries)
return 0;
desc = &ldt->entries[idx];

2
arch/x86/include/asm/efi.h
View File

@ -74,7 +74,7 @@ struct efi_scratch {
__kernel_fpu_begin(); \
\
if (efi_scratch.use_pgd) { \
efi_scratch.prev_cr3 = read_cr3(); \
efi_scratch.prev_cr3 = __read_cr3(); \
write_cr3((unsigned long)efi_scratch.efi_pgt); \
__flush_tlb_all(); \
} \

2
arch/x86/include/asm/hardirq.h
View File

@ -22,8 +22,8 @@ typedef struct {
#ifdef CONFIG_SMP
unsigned int irq_resched_count;
unsigned int irq_call_count;
unsigned int irq_tlb_count;
#endif
unsigned int irq_tlb_count;
#ifdef CONFIG_X86_THERMAL_VECTOR
unsigned int irq_thermal_count;
#endif

6
arch/x86/include/asm/mmu.h
View File

@ -37,12 +37,6 @@ typedef struct {
#endif
} mm_context_t;
#ifdef CONFIG_SMP
void leave_mm(int cpu);
#else
static inline void leave_mm(int cpu)
{
}
#endif
#endif /* _ASM_X86_MMU_H */

63
arch/x86/include/asm/mmu_context.h
View File

@ -47,7 +47,7 @@ struct ldt_struct {
* allocations, but it's not worth trying to optimize.
*/
struct desc_struct *entries;
unsigned int size;
unsigned int nr_entries;
};
/*
@ -87,22 +87,46 @@ static inline void load_mm_ldt(struct mm_struct *mm)
*/
if (unlikely(ldt))
set_ldt(ldt->entries, ldt->size);
set_ldt(ldt->entries, ldt->nr_entries);
else
clear_LDT();
#else
clear_LDT();
#endif
}
static inline void switch_ldt(struct mm_struct *prev, struct mm_struct *next)
{
#ifdef CONFIG_MODIFY_LDT_SYSCALL
/*
* Load the LDT if either the old or new mm had an LDT.
*
* An mm will never go from having an LDT to not having an LDT. Two
* mms never share an LDT, so we don't gain anything by checking to
* see whether the LDT changed. There's also no guarantee that
* prev->context.ldt actually matches LDTR, but, if LDTR is non-NULL,
* then prev->context.ldt will also be non-NULL.
*
* If we really cared, we could optimize the case where prev == next
* and we're exiting lazy mode. Most of the time, if this happens,
* we don't actually need to reload LDTR, but modify_ldt() is mostly
* used by legacy code and emulators where we don't need this level of
* performance.
*
* This uses | instead of || because it generates better code.
*/
if (unlikely((unsigned long)prev->context.ldt |
(unsigned long)next->context.ldt))
load_mm_ldt(next);
#endif
DEBUG_LOCKS_WARN_ON(preemptible());
}
static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
#ifdef CONFIG_SMP
if (this_cpu_read(cpu_tlbstate.state) == TLBSTATE_OK)
this_cpu_write(cpu_tlbstate.state, TLBSTATE_LAZY);
#endif
}
static inline int init_new_context(struct task_struct *tsk,
@ -220,18 +244,6 @@ static inline int vma_pkey(struct vm_area_struct *vma)
}
#endif
static inline bool __pkru_allows_pkey(u16 pkey, bool write)
{
u32 pkru = read_pkru();
if (!__pkru_allows_read(pkru, pkey))
return false;
if (write && !__pkru_allows_write(pkru, pkey))
return false;
return true;
}
/*
* We only want to enforce protection keys on the current process
* because we effectively have no access to PKRU for other
@ -268,4 +280,23 @@ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
return __pkru_allows_pkey(vma_pkey(vma), write);
}
/*
* This can be used from process context to figure out what the value of
* CR3 is without needing to do a (slow) __read_cr3().
*
* It's intended to be used for code like KVM that sneakily changes CR3
* and needs to restore it. It needs to be used very carefully.
*/
static inline unsigned long __get_current_cr3_fast(void)
{
unsigned long cr3 = __pa(this_cpu_read(cpu_tlbstate.loaded_mm)->pgd);
/* For now, be very restrictive about when this can be called. */
VM_WARN_ON(in_nmi() || !in_atomic());
VM_BUG_ON(cr3 != __read_cr3());
return cr3;
}
#endif /* _ASM_X86_MMU_CONTEXT_H */

8
arch/x86/include/asm/paravirt.h
View File

@ -61,7 +61,7 @@ static inline void write_cr2(unsigned long x)
PVOP_VCALL1(pv_mmu_ops.write_cr2, x);
}
static inline unsigned long read_cr3(void)
static inline unsigned long __read_cr3(void)
{
return PVOP_CALL0(unsigned long, pv_mmu_ops.read_cr3);
}
@ -312,11 +312,9 @@ static inline void __flush_tlb_single(unsigned long addr)
}
static inline void flush_tlb_others(const struct cpumask *cpumask,
struct mm_struct *mm,
unsigned long start,
unsigned long end)
const struct flush_tlb_info *info)
{
PVOP_VCALL4(pv_mmu_ops.flush_tlb_others, cpumask, mm, start, end);
PVOP_VCALL2(pv_mmu_ops.flush_tlb_others, cpumask, info);
}
static inline int paravirt_pgd_alloc(struct mm_struct *mm)

5
arch/x86/include/asm/paravirt_types.h
View File

@ -51,6 +51,7 @@ struct mm_struct;
struct desc_struct;
struct task_struct;
struct cpumask;
struct flush_tlb_info;
/*
* Wrapper type for pointers to code which uses the non-standard
@ -223,9 +224,7 @@ struct pv_mmu_ops {
void (*flush_tlb_kernel)(void);
void (*flush_tlb_single)(unsigned long addr);
void (*flush_tlb_others)(const struct cpumask *cpus,
struct mm_struct *mm,
unsigned long start,
unsigned long end);
const struct flush_tlb_info *info);
/* Hooks for allocating and freeing a pagetable top-level */
int (*pgd_alloc)(struct mm_struct *mm);

47
arch/x86/include/asm/pgtable-3level.h
View File

@ -212,4 +212,51 @@ static inline pud_t native_pudp_get_and_clear(pud_t *pudp)
#define __pte_to_swp_entry(pte) ((swp_entry_t){ (pte).pte_high })
#define __swp_entry_to_pte(x) ((pte_t){ { .pte_high = (x).val } })
#define gup_get_pte gup_get_pte
/*
* WARNING: only to be used in the get_user_pages_fast() implementation.
*
* With get_user_pages_fast(), we walk down the pagetables without taking
* any locks. For this we would like to load the pointers atomically,
* but that is not possible (without expensive cmpxchg8b) on PAE. What
* we do have is the guarantee that a PTE will only either go from not
* present to present, or present to not present or both -- it will not
* switch to a completely different present page without a TLB flush in
* between; something that we are blocking by holding interrupts off.
*
* Setting ptes from not present to present goes:
*
* ptep->pte_high = h;
* smp_wmb();
* ptep->pte_low = l;
*
* And present to not present goes:
*
* ptep->pte_low = 0;
* smp_wmb();
* ptep->pte_high = 0;
*
* We must ensure here that the load of pte_low sees 'l' iff pte_high
* sees 'h'. We load pte_high *after* loading pte_low, which ensures we
* don't see an older value of pte_high. *Then* we recheck pte_low,
* which ensures that we haven't picked up a changed pte high. We might
* have gotten rubbish values from pte_low and pte_high, but we are
* guaranteed that pte_low will not have the present bit set *unless*
* it is 'l'. Because get_user_pages_fast() only operates on present ptes
* we're safe.
*/
static inline pte_t gup_get_pte(pte_t *ptep)
{
pte_t pte;
do {
pte.pte_low = ptep->pte_low;
smp_rmb();
pte.pte_high = ptep->pte_high;
smp_rmb();
} while (unlikely(pte.pte_low != ptep->pte_low));
return pte;
}
#endif /* _ASM_X86_PGTABLE_3LEVEL_H */

55
arch/x86/include/asm/pgtable.h
View File

@ -244,6 +244,11 @@ static inline int pud_devmap(pud_t pud)
return 0;
}
#endif
static inline int pgd_devmap(pgd_t pgd)
{
return 0;
}
#endif
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
@ -917,7 +922,7 @@ extern pgd_t trampoline_pgd_entry;
static inline void __meminit init_trampoline_default(void)
{
/* Default trampoline pgd value */
trampoline_pgd_entry = init_level4_pgt[pgd_index(__PAGE_OFFSET)];
trampoline_pgd_entry = init_top_pgt[pgd_index(__PAGE_OFFSET)];
}
# ifdef CONFIG_RANDOMIZE_MEMORY
void __meminit init_trampoline(void);
@ -1185,6 +1190,54 @@ static inline u16 pte_flags_pkey(unsigned long pte_flags)
#endif
}
static inline bool __pkru_allows_pkey(u16 pkey, bool write)
{
u32 pkru = read_pkru();
if (!__pkru_allows_read(pkru, pkey))
return false;
if (write && !__pkru_allows_write(pkru, pkey))
return false;
return true;
}
/*
* 'pteval' can come from a PTE, PMD or PUD. We only check
* _PAGE_PRESENT, _PAGE_USER, and _PAGE_RW in here which are the
* same value on all 3 types.
*/
static inline bool __pte_access_permitted(unsigned long pteval, bool write)
{
unsigned long need_pte_bits = _PAGE_PRESENT|_PAGE_USER;
if (write)
need_pte_bits |= _PAGE_RW;
if ((pteval & need_pte_bits) != need_pte_bits)
return 0;
return __pkru_allows_pkey(pte_flags_pkey(pteval), write);
}
#define pte_access_permitted pte_access_permitted
static inline bool pte_access_permitted(pte_t pte, bool write)
{
return __pte_access_permitted(pte_val(pte), write);
}
#define pmd_access_permitted pmd_access_permitted
static inline bool pmd_access_permitted(pmd_t pmd, bool write)
{
return __pte_access_permitted(pmd_val(pmd), write);
}
#define pud_access_permitted pud_access_permitted
static inline bool pud_access_permitted(pud_t pud, bool write)
{
return __pte_access_permitted(pud_val(pud), write);
}
#include <asm-generic/pgtable.h>
#endif /* __ASSEMBLY__ */

22
arch/x86/include/asm/pgtable_64.h
View File

@ -14,15 +14,17 @@
#include <linux/bitops.h>
#include <linux/threads.h>
extern p4d_t level4_kernel_pgt[512];
extern p4d_t level4_ident_pgt[512];
extern pud_t level3_kernel_pgt[512];
extern pud_t level3_ident_pgt[512];
extern pmd_t level2_kernel_pgt[512];
extern pmd_t level2_fixmap_pgt[512];
extern pmd_t level2_ident_pgt[512];
extern pte_t level1_fixmap_pgt[512];
extern pgd_t init_level4_pgt[];
extern pgd_t init_top_pgt[];
#define swapper_pg_dir init_level4_pgt
#define swapper_pg_dir init_top_pgt
extern void paging_init(void);
@ -227,6 +229,20 @@ extern void cleanup_highmap(void);
extern void init_extra_mapping_uc(unsigned long phys, unsigned long size);
extern void init_extra_mapping_wb(unsigned long phys, unsigned long size);
#endif /* !__ASSEMBLY__ */
#define gup_fast_permitted gup_fast_permitted
static inline bool gup_fast_permitted(unsigned long start, int nr_pages,
int write)
{
unsigned long len, end;
len = (unsigned long)nr_pages << PAGE_SHIFT;
end = start + len;
if (end < start)
return false;
if (end >> __VIRTUAL_MASK_SHIFT)
return false;
return true;
}
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_X86_PGTABLE_64_H */

36
arch/x86/include/asm/processor-flags.h
View File

@ -8,4 +8,40 @@
#else
#define X86_VM_MASK 0 /* No VM86 support */
#endif
/*
* CR3's layout varies depending on several things.
*
* If CR4.PCIDE is set (64-bit only), then CR3[11:0] is the address space ID.
* If PAE is enabled, then CR3[11:5] is part of the PDPT address
* (i.e. it's 32-byte aligned, not page-aligned) and CR3[4:0] is ignored.
* Otherwise (non-PAE, non-PCID), CR3[3] is PWT, CR3[4] is PCD, and
* CR3[2:0] and CR3[11:5] are ignored.
*
* In all cases, Linux puts zeros in the low ignored bits and in PWT and PCD.
*
* CR3[63] is always read as zero. If CR4.PCIDE is set, then CR3[63] may be
* written as 1 to prevent the write to CR3 from flushing the TLB.
*
* On systems with SME, one bit (in a variable position!) is stolen to indicate
* that the top-level paging structure is encrypted.
*
* All of the remaining bits indicate the physical address of the top-level
* paging structure.
*
* CR3_ADDR_MASK is the mask used by read_cr3_pa().
*/
#ifdef CONFIG_X86_64
/* Mask off the address space ID bits. */
#define CR3_ADDR_MASK 0x7FFFFFFFFFFFF000ull
#define CR3_PCID_MASK 0xFFFull
#else
/*
* CR3_ADDR_MASK needs at least bits 31:5 set on PAE systems, and we save
* a tiny bit of code size by setting all the bits.
*/
#define CR3_ADDR_MASK 0xFFFFFFFFull
#define CR3_PCID_MASK 0ull
#endif
#endif /* _ASM_X86_PROCESSOR_FLAGS_H */

8
arch/x86/include/asm/processor.h
View File

@ -231,6 +231,14 @@ native_cpuid_reg(ebx)
native_cpuid_reg(ecx)
native_cpuid_reg(edx)
/*
* Friendlier CR3 helpers.
*/
static inline unsigned long read_cr3_pa(void)
{
return __read_cr3() & CR3_ADDR_MASK;
}
static inline void load_cr3(pgd_t *pgdir)
{
write_cr3(__pa(pgdir));

10
arch/x86/include/asm/special_insns.h
View File

@ -39,7 +39,7 @@ static inline void native_write_cr2(unsigned long val)
asm volatile("mov %0,%%cr2": : "r" (val), "m" (__force_order));
}
static inline unsigned long native_read_cr3(void)
static inline unsigned long __native_read_cr3(void)
{
unsigned long val;
asm volatile("mov %%cr3,%0\n\t" : "=r" (val), "=m" (__force_order));
@ -159,9 +159,13 @@ static inline void write_cr2(unsigned long x)
native_write_cr2(x);
}
static inline unsigned long read_cr3(void)
/*
* Careful! CR3 contains more than just an address. You probably want
* read_cr3_pa() instead.
*/
static inline unsigned long __read_cr3(void)
{
return native_read_cr3();
return __native_read_cr3();
}
static inline void write_cr3(unsigned long x)

14
arch/x86/include/asm/tlbbatch.h Normal file
View File

@ -0,0 +1,14 @@
#ifndef _ARCH_X86_TLBBATCH_H
#define _ARCH_X86_TLBBATCH_H
#include <linux/cpumask.h>
struct arch_tlbflush_unmap_batch {
/*
* Each bit set is a CPU that potentially has a TLB entry for one of
* the PFNs being flushed..
*/
struct cpumask cpumask;
};
#endif /* _ARCH_X86_TLBBATCH_H */

114
arch/x86/include/asm/tlbflush.h
View File

@ -7,6 +7,7 @@
#include <asm/processor.h>
#include <asm/cpufeature.h>
#include <asm/special_insns.h>
#include <asm/smp.h>
static inline void __invpcid(unsigned long pcid, unsigned long addr,
unsigned long type)
@ -65,10 +66,14 @@ static inline void invpcid_flush_all_nonglobals(void)
#endif
struct tlb_state {
#ifdef CONFIG_SMP
struct mm_struct *active_mm;
/*
* cpu_tlbstate.loaded_mm should match CR3 whenever interrupts
* are on. This means that it may not match current->active_mm,
* which will contain the previous user mm when we're in lazy TLB
* mode even if we've already switched back to swapper_pg_dir.
*/
struct mm_struct *loaded_mm;
int state;
#endif
/*
* Access to this CR4 shadow and to H/W CR4 is protected by
@ -151,7 +156,7 @@ static inline void __native_flush_tlb(void)
* back:
*/
preempt_disable();
native_write_cr3(native_read_cr3());
native_write_cr3(__native_read_cr3());
preempt_enable();
}
@ -220,84 +225,16 @@ static inline void __flush_tlb_one(unsigned long addr)
* - flush_tlb_page(vma, vmaddr) flushes one page
* - flush_tlb_range(vma, start, end) flushes a range of pages
* - flush_tlb_kernel_range(start, end) flushes a range of kernel pages
* - flush_tlb_others(cpumask, mm, start, end) flushes TLBs on other cpus
* - flush_tlb_others(cpumask, info) flushes TLBs on other cpus
*
* ..but the i386 has somewhat limited tlb flushing capabilities,
* and page-granular flushes are available only on i486 and up.
*/
#ifndef CONFIG_SMP
/* "_up" is for UniProcessor.
*
* This is a helper for other header functions. *Not* intended to be called
* directly. All global TLB flushes need to either call this, or to bump the
* vm statistics themselves.
*/
static inline void __flush_tlb_up(void)
{
count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
__flush_tlb();
}
static inline void flush_tlb_all(void)
{
count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
__flush_tlb_all();
}
static inline void local_flush_tlb(void)
{
__flush_tlb_up();
}
static inline void flush_tlb_mm(struct mm_struct *mm)
{
if (mm == current->active_mm)
__flush_tlb_up();
}
static inline void flush_tlb_page(struct vm_area_struct *vma,
unsigned long addr)
{
if (vma->vm_mm == current->active_mm)
__flush_tlb_one(addr);
}
static inline void flush_tlb_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
if (vma->vm_mm == current->active_mm)
__flush_tlb_up();
}
static inline void flush_tlb_mm_range(struct mm_struct *mm,
unsigned long start, unsigned long end, unsigned long vmflag)
{
if (mm == current->active_mm)
__flush_tlb_up();
}
static inline void native_flush_tlb_others(const struct cpumask *cpumask,
struct mm_struct *mm,
unsigned long start,
unsigned long end)
{
}
static inline void reset_lazy_tlbstate(void)
{
}
static inline void flush_tlb_kernel_range(unsigned long start,
unsigned long end)
{
flush_tlb_all();
}
#else /* SMP */
#include <asm/smp.h>
struct flush_tlb_info {
struct mm_struct *mm;
unsigned long start;
unsigned long end;
};
#define local_flush_tlb() __flush_tlb()
@ -307,29 +244,32 @@ static inline void flush_tlb_kernel_range(unsigned long start,
flush_tlb_mm_range(vma->vm_mm, start, end, vma->vm_flags)
extern void flush_tlb_all(void);
extern void flush_tlb_page(struct vm_area_struct *, unsigned long);
extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
unsigned long end, unsigned long vmflag);
extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);
static inline void flush_tlb_page(struct vm_area_struct *vma, unsigned long a)
{
flush_tlb_mm_range(vma->vm_mm, a, a + PAGE_SIZE, VM_NONE);
}
void native_flush_tlb_others(const struct cpumask *cpumask,
struct mm_struct *mm,
unsigned long start, unsigned long end);
const struct flush_tlb_info *info);
#define TLBSTATE_OK 1
#define TLBSTATE_LAZY 2
static inline void reset_lazy_tlbstate(void)
static inline void arch_tlbbatch_add_mm(struct arch_tlbflush_unmap_batch *batch,
struct mm_struct *mm)
{
this_cpu_write(cpu_tlbstate.state, 0);
this_cpu_write(cpu_tlbstate.active_mm, &init_mm);
cpumask_or(&batch->cpumask, &batch->cpumask, mm_cpumask(mm));
}
#endif /* SMP */
extern void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch);
#ifndef CONFIG_PARAVIRT
#define flush_tlb_others(mask, mm, start, end) \
native_flush_tlb_others(mask, mm, start, end)
#define flush_tlb_others(mask, info) \
native_flush_tlb_others(mask, info)
#endif
#endif /* _ASM_X86_TLBFLUSH_H */

11
arch/x86/include/asm/uv/uv.h
View File

@ -1,6 +1,8 @@
#ifndef _ASM_X86_UV_UV_H
#define _ASM_X86_UV_UV_H
#include <asm/tlbflush.h>
enum uv_system_type {UV_NONE, UV_LEGACY_APIC, UV_X2APIC, UV_NON_UNIQUE_APIC};
struct cpumask;
@ -15,10 +17,7 @@ extern void uv_cpu_init(void);
extern void uv_nmi_init(void);
extern void uv_system_init(void);
extern const struct cpumask *uv_flush_tlb_others(const struct cpumask *cpumask,
struct mm_struct *mm,
unsigned long start,
unsigned long end,
unsigned int cpu);
const struct flush_tlb_info *info);
#else /* X86_UV */
@ -28,8 +27,8 @@ static inline int is_uv_hubless(void) { return 0; }
static inline void uv_cpu_init(void) { }
static inline void uv_system_init(void) { }
static inline const struct cpumask *
uv_flush_tlb_others(const struct cpumask *cpumask, struct mm_struct *mm,
unsigned long start, unsigned long end, unsigned int cpu)
uv_flush_tlb_others(const struct cpumask *cpumask,
const struct flush_tlb_info *info)
{ return cpumask; }
#endif /* X86_UV */

2
arch/x86/include/uapi/asm/processor-flags.h
View File

@ -104,6 +104,8 @@
#define X86_CR4_OSFXSR _BITUL(X86_CR4_OSFXSR_BIT)
#define X86_CR4_OSXMMEXCPT_BIT 10 /* enable unmasked SSE exceptions */
#define X86_CR4_OSXMMEXCPT _BITUL(X86_CR4_OSXMMEXCPT_BIT)
#define X86_CR4_LA57_BIT 12 /* enable 5-level page tables */
#define X86_CR4_LA57 _BITUL(X86_CR4_LA57_BIT)
#define X86_CR4_VMXE_BIT 13 /* enable VMX virtualization */
#define X86_CR4_VMXE _BITUL(X86_CR4_VMXE_BIT)
#define X86_CR4_SMXE_BIT 14 /* enable safer mode (TXT) */

1
arch/x86/kernel/Makefile
View File

@ -18,6 +18,7 @@ CFLAGS_REMOVE_pvclock.o = -pg
CFLAGS_REMOVE_kvmclock.o = -pg
CFLAGS_REMOVE_ftrace.o = -pg
CFLAGS_REMOVE_early_printk.o = -pg
CFLAGS_REMOVE_head64.o = -pg
endif
KASAN_SANITIZE_head$(BITS).o := n

2
arch/x86/kernel/espfix_64.c
View File

@ -125,7 +125,7 @@ void __init init_espfix_bsp(void)
p4d_t *p4d;
/* Install the espfix pud into the kernel page directory */
pgd = &init_level4_pgt[pgd_index(ESPFIX_BASE_ADDR)];
pgd = &init_top_pgt[pgd_index(ESPFIX_BASE_ADDR)];
p4d = p4d_alloc(&init_mm, pgd, ESPFIX_BASE_ADDR);
p4d_populate(&init_mm, p4d, espfix_pud_page);

145
arch/x86/kernel/head64.c
View File

@ -33,17 +33,120 @@
/*
* Manage page tables very early on.
*/
extern pgd_t early_level4_pgt[PTRS_PER_PGD];
extern pgd_t early_top_pgt[PTRS_PER_PGD];
extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD];
static unsigned int __initdata next_early_pgt = 2;
static unsigned int __initdata next_early_pgt;
pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX);
#define __head __section(.head.text)
static void __head *fixup_pointer(void *ptr, unsigned long physaddr)
{
return ptr - (void *)_text + (void *)physaddr;
}
void __head __startup_64(unsigned long physaddr)
{
unsigned long load_delta, *p;
pgdval_t *pgd;
p4dval_t *p4d;
pudval_t *pud;
pmdval_t *pmd, pmd_entry;
int i;
/* Is the address too large? */
if (physaddr >> MAX_PHYSMEM_BITS)
for (;;);
/*
* Compute the delta between the address I am compiled to run at
* and the address I am actually running at.
*/
load_delta = physaddr - (unsigned long)(_text - __START_KERNEL_map);
/* Is the address not 2M aligned? */
if (load_delta & ~PMD_PAGE_MASK)
for (;;);
/* Fixup the physical addresses in the page table */
pgd = fixup_pointer(&early_top_pgt, physaddr);
pgd[pgd_index(__START_KERNEL_map)] += load_delta;
if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
p4d = fixup_pointer(&level4_kernel_pgt, physaddr);
p4d[511] += load_delta;
}
pud = fixup_pointer(&level3_kernel_pgt, physaddr);
pud[510] += load_delta;
pud[511] += load_delta;
pmd = fixup_pointer(level2_fixmap_pgt, physaddr);
pmd[506] += load_delta;
/*
* Set up the identity mapping for the switchover. These
* entries should *NOT* have the global bit set! This also
* creates a bunch of nonsense entries but that is fine --
* it avoids problems around wraparound.
*/
pud = fixup_pointer(early_dynamic_pgts[next_early_pgt++], physaddr);
pmd = fixup_pointer(early_dynamic_pgts[next_early_pgt++], physaddr);
if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
p4d = fixup_pointer(early_dynamic_pgts[next_early_pgt++], physaddr);
i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
pgd[i + 0] = (pgdval_t)p4d + _KERNPG_TABLE;
pgd[i + 1] = (pgdval_t)p4d + _KERNPG_TABLE;
i = (physaddr >> P4D_SHIFT) % PTRS_PER_P4D;
p4d[i + 0] = (pgdval_t)pud + _KERNPG_TABLE;
p4d[i + 1] = (pgdval_t)pud + _KERNPG_TABLE;
} else {
i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
pgd[i + 0] = (pgdval_t)pud + _KERNPG_TABLE;
pgd[i + 1] = (pgdval_t)pud + _KERNPG_TABLE;
}
i = (physaddr >> PUD_SHIFT) % PTRS_PER_PUD;
pud[i + 0] = (pudval_t)pmd + _KERNPG_TABLE;
pud[i + 1] = (pudval_t)pmd + _KERNPG_TABLE;
pmd_entry = __PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL;
pmd_entry += physaddr;
for (i = 0; i < DIV_ROUND_UP(_end - _text, PMD_SIZE); i++) {
int idx = i + (physaddr >> PMD_SHIFT) % PTRS_PER_PMD;
pmd[idx] = pmd_entry + i * PMD_SIZE;
}
/*
* Fixup the kernel text+data virtual addresses. Note that
* we might write invalid pmds, when the kernel is relocated
* cleanup_highmap() fixes this up along with the mappings
* beyond _end.
*/
pmd = fixup_pointer(level2_kernel_pgt, physaddr);
for (i = 0; i < PTRS_PER_PMD; i++) {
if (pmd[i] & _PAGE_PRESENT)
pmd[i] += load_delta;
}
/* Fixup phys_base */
p = fixup_pointer(&phys_base, physaddr);
*p += load_delta;
}
/* Wipe all early page tables except for the kernel symbol map */
static void __init reset_early_page_tables(void)
{
memset(early_level4_pgt, 0, sizeof(pgd_t)*(PTRS_PER_PGD-1));
memset(early_top_pgt, 0, sizeof(pgd_t)*(PTRS_PER_PGD-1));
next_early_pgt = 0;
write_cr3(__pa_nodebug(early_level4_pgt));
write_cr3(__pa_nodebug(early_top_pgt));
}
/* Create a new PMD entry */
@ -51,15 +154,16 @@ int __init early_make_pgtable(unsigned long address)
{
unsigned long physaddr = address - __PAGE_OFFSET;
pgdval_t pgd, *pgd_p;
p4dval_t p4d, *p4d_p;
pudval_t pud, *pud_p;
pmdval_t pmd, *pmd_p;
/* Invalid address or early pgt is done ? */
if (physaddr >= MAXMEM || read_cr3() != __pa_nodebug(early_level4_pgt))
if (physaddr >= MAXMEM || read_cr3_pa() != __pa_nodebug(early_top_pgt))
return -1;
again:
pgd_p = &early_level4_pgt[pgd_index(address)].pgd;
pgd_p = &early_top_pgt[pgd_index(address)].pgd;
pgd = *pgd_p;
/*
@ -67,8 +171,25 @@ again:
* critical -- __PAGE_OFFSET would point us back into the dynamic
* range and we might end up looping forever...
*/
if (pgd)
pud_p = (pudval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
if (!IS_ENABLED(CONFIG_X86_5LEVEL))
p4d_p = pgd_p;
else if (pgd)
p4d_p = (p4dval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
else {
if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
reset_early_page_tables();
goto again;
}
p4d_p = (p4dval_t *)early_dynamic_pgts[next_early_pgt++];
memset(p4d_p, 0, sizeof(*p4d_p) * PTRS_PER_P4D);
*pgd_p = (pgdval_t)p4d_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
}
p4d_p += p4d_index(address);
p4d = *p4d_p;
if (p4d)
pud_p = (pudval_t *)((p4d & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
else {
if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
reset_early_page_tables();
@ -77,7 +198,7 @@ again:
pud_p = (pudval_t *)early_dynamic_pgts[next_early_pgt++];
memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
*pgd_p = (pgdval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
*p4d_p = (p4dval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
}
pud_p += pud_index(address);
pud = *pud_p;
@ -156,7 +277,7 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
clear_bss();
clear_page(init_level4_pgt);
clear_page(init_top_pgt);
kasan_early_init();
@ -171,8 +292,8 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
*/
load_ucode_bsp();
/* set init_level4_pgt kernel high mapping*/
init_level4_pgt[511] = early_level4_pgt[511];
/* set init_top_pgt kernel high mapping*/
init_top_pgt[511] = early_top_pgt[511];
x86_64_start_reservations(real_mode_data);
}

131
arch/x86/kernel/head_64.S
View File

@ -37,10 +37,11 @@
*
*/
#define p4d_index(x) (((x) >> P4D_SHIFT) & (PTRS_PER_P4D-1))
#define pud_index(x) (((x) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
L4_PAGE_OFFSET = pgd_index(__PAGE_OFFSET_BASE)
L4_START_KERNEL = pgd_index(__START_KERNEL_map)
PGD_PAGE_OFFSET = pgd_index(__PAGE_OFFSET_BASE)
PGD_START_KERNEL = pgd_index(__START_KERNEL_map)
L3_START_KERNEL = pud_index(__START_KERNEL_map)
.text
@ -72,101 +73,12 @@ startup_64:
/* Sanitize CPU configuration */
call verify_cpu
/*
* Compute the delta between the address I am compiled to run at and the
* address I am actually running at.
*/
leaq _text(%rip), %rbp
subq $_text - __START_KERNEL_map, %rbp
/* Is the address not 2M aligned? */
testl $~PMD_PAGE_MASK, %ebp
jnz bad_address
/*
* Is the address too large?
*/
leaq _text(%rip), %rax
shrq $MAX_PHYSMEM_BITS, %rax
jnz bad_address
/*
* Fixup the physical addresses in the page table
*/
addq %rbp, early_level4_pgt + (L4_START_KERNEL*8)(%rip)
addq %rbp, level3_kernel_pgt + (510*8)(%rip)
addq %rbp, level3_kernel_pgt + (511*8)(%rip)
addq %rbp, level2_fixmap_pgt + (506*8)(%rip)
/*
* Set up the identity mapping for the switchover. These
* entries should *NOT* have the global bit set! This also
* creates a bunch of nonsense entries but that is fine --
* it avoids problems around wraparound.
*/
leaq _text(%rip), %rdi
leaq early_level4_pgt(%rip), %rbx
pushq %rsi
call __startup_64
popq %rsi
movq %rdi, %rax
shrq $PGDIR_SHIFT, %rax
leaq (PAGE_SIZE + _KERNPG_TABLE)(%rbx), %rdx
movq %rdx, 0(%rbx,%rax,8)
movq %rdx, 8(%rbx,%rax,8)
addq $PAGE_SIZE, %rdx
movq %rdi, %rax
shrq $PUD_SHIFT, %rax
andl $(PTRS_PER_PUD-1), %eax
movq %rdx, PAGE_SIZE(%rbx,%rax,8)
incl %eax
andl $(PTRS_PER_PUD-1), %eax
movq %rdx, PAGE_SIZE(%rbx,%rax,8)
addq $PAGE_SIZE * 2, %rbx
movq %rdi, %rax
shrq $PMD_SHIFT, %rdi
addq $(__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL), %rax
leaq (_end - 1)(%rip), %rcx
shrq $PMD_SHIFT, %rcx
subq %rdi, %rcx
incl %ecx
1:
andq $(PTRS_PER_PMD - 1), %rdi
movq %rax, (%rbx,%rdi,8)
incq %rdi
addq $PMD_SIZE, %rax
decl %ecx
jnz 1b
test %rbp, %rbp
jz .Lskip_fixup
/*
* Fixup the kernel text+data virtual addresses. Note that
* we might write invalid pmds, when the kernel is relocated
* cleanup_highmap() fixes this up along with the mappings
* beyond _end.
*/
leaq level2_kernel_pgt(%rip), %rdi
leaq PAGE_SIZE(%rdi), %r8
/* See if it is a valid page table entry */
1: testb $_PAGE_PRESENT, 0(%rdi)
jz 2f
addq %rbp, 0(%rdi)
/* Go to the next page */
2: addq $8, %rdi
cmp %r8, %rdi
jne 1b
/* Fixup phys_base */
addq %rbp, phys_base(%rip)
.Lskip_fixup:
movq $(early_level4_pgt - __START_KERNEL_map), %rax
movq $(early_top_pgt - __START_KERNEL_map), %rax
jmp 1f
ENTRY(secondary_startup_64)
/*
@ -186,14 +98,17 @@ ENTRY(secondary_startup_64)
/* Sanitize CPU configuration */
call verify_cpu
movq $(init_level4_pgt - __START_KERNEL_map), %rax
movq $(init_top_pgt - __START_KERNEL_map), %rax
1:
/* Enable PAE mode and PGE */
/* Enable PAE mode, PGE and LA57 */
movl $(X86_CR4_PAE | X86_CR4_PGE), %ecx
#ifdef CONFIG_X86_5LEVEL
orl $X86_CR4_LA57, %ecx
#endif
movq %rcx, %cr4
/* Setup early boot stage 4 level pagetables. */
/* Setup early boot stage 4-/5-level pagetables. */
addq phys_base(%rip), %rax
movq %rax, %cr3
@ -417,9 +332,13 @@ GLOBAL(name)
.endr
__INITDATA
NEXT_PAGE(early_level4_pgt)
NEXT_PAGE(early_top_pgt)
.fill 511,8,0
#ifdef CONFIG_X86_5LEVEL
.quad level4_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE
#else
.quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE
#endif
NEXT_PAGE(early_dynamic_pgts)
.fill 512*EARLY_DYNAMIC_PAGE_TABLES,8,0
@ -427,14 +346,14 @@ NEXT_PAGE(early_dynamic_pgts)
.data
#ifndef CONFIG_XEN
NEXT_PAGE(init_level4_pgt)
NEXT_PAGE(init_top_pgt)
.fill 512,8,0
#else
NEXT_PAGE(init_level4_pgt)
NEXT_PAGE(init_top_pgt)
.quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE
.org init_level4_pgt + L4_PAGE_OFFSET*8, 0
.org init_top_pgt + PGD_PAGE_OFFSET*8, 0
.quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE
.org init_level4_pgt + L4_START_KERNEL*8, 0
.org init_top_pgt + PGD_START_KERNEL*8, 0
/* (2^48-(2*1024*1024*1024))/(2^39) = 511 */
.quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE
@ -448,6 +367,12 @@ NEXT_PAGE(level2_ident_pgt)
PMDS(0, __PAGE_KERNEL_IDENT_LARGE_EXEC, PTRS_PER_PMD)
#endif
#ifdef CONFIG_X86_5LEVEL
NEXT_PAGE(level4_kernel_pgt)
.fill 511,8,0
.quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE
#endif
NEXT_PAGE(level3_kernel_pgt)
.fill L3_START_KERNEL,8,0
/* (2^48-(2*1024*1024*1024)-((2^39)*511))/(2^30) = 510 */

56
arch/x86/kernel/ldt.c
View File

@ -22,24 +22,25 @@
#include <asm/syscalls.h>
/* context.lock is held for us, so we don't need any locking. */
static void flush_ldt(void *current_mm)
static void flush_ldt(void *__mm)
{
struct mm_struct *mm = __mm;
mm_context_t *pc;
if (current->active_mm != current_mm)
if (this_cpu_read(cpu_tlbstate.loaded_mm) != mm)
return;
pc = &current->active_mm->context;
set_ldt(pc->ldt->entries, pc->ldt->size);
pc = &mm->context;
set_ldt(pc->ldt->entries, pc->ldt->nr_entries);
}
/* The caller must call finalize_ldt_struct on the result. LDT starts zeroed. */
static struct ldt_struct *alloc_ldt_struct(unsigned int size)
static struct ldt_struct *alloc_ldt_struct(unsigned int num_entries)
{
struct ldt_struct *new_ldt;
unsigned int alloc_size;
if (size > LDT_ENTRIES)
if (num_entries > LDT_ENTRIES)
return NULL;
new_ldt = kmalloc(sizeof(struct ldt_struct), GFP_KERNEL);
@ -47,7 +48,7 @@ static struct ldt_struct *alloc_ldt_struct(unsigned int size)
return NULL;
BUILD_BUG_ON(LDT_ENTRY_SIZE != sizeof(struct desc_struct));
alloc_size = size * LDT_ENTRY_SIZE;
alloc_size = num_entries * LDT_ENTRY_SIZE;
/*
* Xen is very picky: it requires a page-aligned LDT that has no
@ -65,14 +66,14 @@ static struct ldt_struct *alloc_ldt_struct(unsigned int size)
return NULL;
}
new_ldt->size = size;
new_ldt->nr_entries = num_entries;
return new_ldt;
}
/* After calling this, the LDT is immutable. */
static void finalize_ldt_struct(struct ldt_struct *ldt)
{
paravirt_alloc_ldt(ldt->entries, ldt->size);
paravirt_alloc_ldt(ldt->entries, ldt->nr_entries);
}
/* context.lock is held */
@ -91,8 +92,8 @@ static void free_ldt_struct(struct ldt_struct *ldt)
if (likely(!ldt))
return;
paravirt_free_ldt(ldt->entries, ldt->size);
if (ldt->size * LDT_ENTRY_SIZE > PAGE_SIZE)
paravirt_free_ldt(ldt->entries, ldt->nr_entries);
if (ldt->nr_entries * LDT_ENTRY_SIZE > PAGE_SIZE)
vfree_atomic(ldt->entries);
else
free_page((unsigned long)ldt->entries);
@ -122,14 +123,14 @@ int init_new_context_ldt(struct task_struct *tsk, struct mm_struct *mm)
goto out_unlock;
}
new_ldt = alloc_ldt_struct(old_mm->context.ldt->size);
new_ldt = alloc_ldt_struct(old_mm->context.ldt->nr_entries);
if (!new_ldt) {
retval = -ENOMEM;
goto out_unlock;
}
memcpy(new_ldt->entries, old_mm->context.ldt->entries,
new_ldt->size * LDT_ENTRY_SIZE);
new_ldt->nr_entries * LDT_ENTRY_SIZE);
finalize_ldt_struct(new_ldt);
mm->context.ldt = new_ldt;
@ -152,9 +153,9 @@ void destroy_context_ldt(struct mm_struct *mm)
static int read_ldt(void __user *ptr, unsigned long bytecount)
{
int retval;
unsigned long size;
struct mm_struct *mm = current->mm;
unsigned long entries_size;
int retval;
mutex_lock(&mm->context.lock);
@ -166,18 +167,18 @@ static int read_ldt(void __user *ptr, unsigned long bytecount)
if (bytecount > LDT_ENTRY_SIZE * LDT_ENTRIES)
bytecount = LDT_ENTRY_SIZE * LDT_ENTRIES;
size = mm->context.ldt->size * LDT_ENTRY_SIZE;
if (size > bytecount)
size = bytecount;
entries_size = mm->context.ldt->nr_entries * LDT_ENTRY_SIZE;
if (entries_size > bytecount)
entries_size = bytecount;
if (copy_to_user(ptr, mm->context.ldt->entries, size)) {
if (copy_to_user(ptr, mm->context.ldt->entries, entries_size)) {
retval = -EFAULT;
goto out_unlock;
}
if (size != bytecount) {
if (entries_size != bytecount) {
/* Zero-fill the rest and pretend we read bytecount bytes. */
if (clear_user(ptr + size, bytecount - size)) {
if (clear_user(ptr + entries_size, bytecount - entries_size)) {
retval = -EFAULT;
goto out_unlock;
}
@ -208,7 +209,7 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode)
{
struct mm_struct *mm = current->mm;
struct ldt_struct *new_ldt, *old_ldt;
unsigned int oldsize, newsize;
unsigned int old_nr_entries, new_nr_entries;
struct user_desc ldt_info;
struct desc_struct ldt;
int error;
@ -247,17 +248,18 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode)
mutex_lock(&mm->context.lock);
old_ldt = mm->context.ldt;
oldsize = old_ldt ? old_ldt->size : 0;
newsize = max(ldt_info.entry_number + 1, oldsize);
old_ldt = mm->context.ldt;
old_nr_entries = old_ldt ? old_ldt->nr_entries : 0;
new_nr_entries = max(ldt_info.entry_number + 1, old_nr_entries);
error = -ENOMEM;
new_ldt = alloc_ldt_struct(newsize);
new_ldt = alloc_ldt_struct(new_nr_entries);
if (!new_ldt)
goto out_unlock;
if (old_ldt)
memcpy(new_ldt->entries, old_ldt->entries, oldsize * LDT_ENTRY_SIZE);
memcpy(new_ldt->entries, old_ldt->entries, old_nr_entries * LDT_ENTRY_SIZE);
new_ldt->entries[ldt_info.entry_number] = ldt;
finalize_ldt_struct(new_ldt);

2
arch/x86/kernel/machine_kexec_64.c
View File

@ -347,7 +347,7 @@ void machine_kexec(struct kimage *image)
void arch_crash_save_vmcoreinfo(void)
{
VMCOREINFO_NUMBER(phys_base);
VMCOREINFO_SYMBOL(init_level4_pgt);
VMCOREINFO_SYMBOL(init_top_pgt);
#ifdef CONFIG_NUMA
VMCOREINFO_SYMBOL(node_data);

2
arch/x86/kernel/paravirt.c
View File

@ -391,7 +391,7 @@ struct pv_mmu_ops pv_mmu_ops __ro_after_init = {
.read_cr2 = native_read_cr2,
.write_cr2 = native_write_cr2,
.read_cr3 = native_read_cr3,
.read_cr3 = __native_read_cr3,
.write_cr3 = native_write_cr3,
.flush_tlb_user = native_flush_tlb,

2
arch/x86/kernel/process_32.c
View File

@ -92,7 +92,7 @@ void __show_regs(struct pt_regs *regs, int all)
cr0 = read_cr0();
cr2 = read_cr2();
cr3 = read_cr3();
cr3 = __read_cr3();
cr4 = __read_cr4();
printk(KERN_DEFAULT "CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n",
cr0, cr2, cr3, cr4);

4
arch/x86/kernel/process_64.c
View File

@ -104,7 +104,7 @@ void __show_regs(struct pt_regs *regs, int all)
cr0 = read_cr0();
cr2 = read_cr2();
cr3 = read_cr3();
cr3 = __read_cr3();
cr4 = __read_cr4();
printk(KERN_DEFAULT "FS: %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n",
@ -142,7 +142,7 @@ void release_thread(struct task_struct *dead_task)
pr_warn("WARNING: dead process %s still has LDT? <%p/%d>\n",
dead_task->comm,
dead_task->mm->context.ldt->entries,
dead_task->mm->context.ldt->size);
dead_task->mm->context.ldt->nr_entries);
BUG();
}
#endif

1
arch/x86/kernel/smpboot.c
View File

@ -1589,7 +1589,6 @@ void native_cpu_die(unsigned int cpu)
void play_dead_common(void)
{
idle_task_exit();
reset_lazy_tlbstate();
/* Ack it */
(void)cpu_report_death();

2
arch/x86/kernel/step.c
View File

@ -34,7 +34,7 @@ unsigned long convert_ip_to_linear(struct task_struct *child, struct pt_regs *re
mutex_lock(&child->mm->context.lock);
if (unlikely(!child->mm->context.ldt ||
seg >= child->mm->context.ldt->size))
seg >= child->mm->context.ldt->nr_entries))
addr = -1L; /* bogus selector, access would fault */
else {
desc = &child->mm->context.ldt->entries[seg];

21
arch/x86/kvm/vmx.c
View File

@ -49,6 +49,7 @@
#include <asm/kexec.h>
#include <asm/apic.h>
#include <asm/irq_remapping.h>
#include <asm/mmu_context.h>
#include "trace.h"
#include "pmu.h"
@ -597,6 +598,7 @@ struct vcpu_vmx {
int gs_ldt_reload_needed;
int fs_reload_needed;
u64 msr_host_bndcfgs;
unsigned long vmcs_host_cr3; /* May not match real cr3 */
unsigned long vmcs_host_cr4; /* May not match real cr4 */
} host_state;
struct {
@ -5013,12 +5015,19 @@ static void vmx_set_constant_host_state(struct vcpu_vmx *vmx)
u32 low32, high32;
unsigned long tmpl;
struct desc_ptr dt;
unsigned long cr0, cr4;
unsigned long cr0, cr3, cr4;
cr0 = read_cr0();
WARN_ON(cr0 & X86_CR0_TS);
vmcs_writel(HOST_CR0, cr0); /* 22.2.3 */
vmcs_writel(HOST_CR3, read_cr3()); /* 22.2.3 FIXME: shadow tables */
/*
* Save the most likely value for this task's CR3 in the VMCS.
* We can't use __get_current_cr3_fast() because we're not atomic.
*/
cr3 = __read_cr3();
vmcs_writel(HOST_CR3, cr3); /* 22.2.3 FIXME: shadow tables */
vmx->host_state.vmcs_host_cr3 = cr3;
/* Save the most likely value for this task's CR4 in the VMCS. */
cr4 = cr4_read_shadow();
@ -8822,7 +8831,7 @@ static void vmx_arm_hv_timer(struct kvm_vcpu *vcpu)
static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
unsigned long debugctlmsr, cr4;
unsigned long debugctlmsr, cr3, cr4;
/* Don't enter VMX if guest state is invalid, let the exit handler
start emulation until we arrive back to a valid state */
@ -8844,6 +8853,12 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
if (test_bit(VCPU_REGS_RIP, (unsigned long *)&vcpu->arch.regs_dirty))
vmcs_writel(GUEST_RIP, vcpu->arch.regs[VCPU_REGS_RIP]);
cr3 = __get_current_cr3_fast();
if (unlikely(cr3 != vmx->host_state.vmcs_host_cr3)) {
vmcs_writel(HOST_CR3, cr3);
vmx->host_state.vmcs_host_cr3 = cr3;
}
cr4 = cr4_read_shadow();
if (unlikely(cr4 != vmx->host_state.vmcs_host_cr4)) {
vmcs_writel(HOST_CR4, cr4);

2
arch/x86/math-emu/fpu_system.h
View File

@ -27,7 +27,7 @@ static inline struct desc_struct FPU_get_ldt_descriptor(unsigned seg)
#ifdef CONFIG_MODIFY_LDT_SYSCALL
seg >>= 3;
mutex_lock(&current->mm->context.lock);
if (current->mm->context.ldt && seg < current->mm->context.ldt->size)
if (current->mm->context.ldt && seg < current->mm->context.ldt->nr_entries)
ret = current->mm->context.ldt->entries[seg];
mutex_unlock(&current->mm->context.lock);
#endif

2
arch/x86/mm/Makefile
View File

@ -2,7 +2,7 @@
KCOV_INSTRUMENT_tlb.o := n
obj-y := init.o init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \
pat.o pgtable.o physaddr.o gup.o setup_nx.o tlb.o
pat.o pgtable.o physaddr.o setup_nx.o tlb.o
# Make sure __phys_addr has no stackprotector
nostackp := $(call cc-option, -fno-stack-protector)

2
arch/x86/mm/dump_pagetables.c
View File

@ -431,7 +431,7 @@ static void ptdump_walk_pgd_level_core(struct seq_file *m, pgd_t *pgd,
bool checkwx)
{
#ifdef CONFIG_X86_64
pgd_t *start = (pgd_t *) &init_level4_pgt;
pgd_t *start = (pgd_t *) &init_top_pgt;
#else
pgd_t *start = swapper_pg_dir;
#endif

10
arch/x86/mm/fault.c
View File

@ -346,7 +346,7 @@ static noinline int vmalloc_fault(unsigned long address)
* Do _not_ use "current" here. We might be inside
* an interrupt in the middle of a task switch..
*/
pgd_paddr = read_cr3();
pgd_paddr = read_cr3_pa();
pmd_k = vmalloc_sync_one(__va(pgd_paddr), address);
if (!pmd_k)
return -1;
@ -388,7 +388,7 @@ static bool low_pfn(unsigned long pfn)
static void dump_pagetable(unsigned long address)
{
pgd_t *base = __va(read_cr3());
pgd_t *base = __va(read_cr3_pa());
pgd_t *pgd = &base[pgd_index(address)];
p4d_t *p4d;
pud_t *pud;
@ -451,7 +451,7 @@ static noinline int vmalloc_fault(unsigned long address)
* happen within a race in page table update. In the later
* case just flush:
*/
pgd = (pgd_t *)__va(read_cr3()) + pgd_index(address);
pgd = (pgd_t *)__va(read_cr3_pa()) + pgd_index(address);
pgd_ref = pgd_offset_k(address);
if (pgd_none(*pgd_ref))
return -1;
@ -555,7 +555,7 @@ static int bad_address(void *p)
static void dump_pagetable(unsigned long address)
{
pgd_t *base = __va(read_cr3() & PHYSICAL_PAGE_MASK);
pgd_t *base = __va(read_cr3_pa());
pgd_t *pgd = base + pgd_index(address);
p4d_t *p4d;
pud_t *pud;
@ -700,7 +700,7 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code,
pgd_t *pgd;
pte_t *pte;
pgd = __va(read_cr3() & PHYSICAL_PAGE_MASK);
pgd = __va(read_cr3_pa());
pgd += pgd_index(address);
pte = lookup_address_in_pgd(pgd, address, &level);

496
arch/x86/mm/gup.c
View File

@ -1,496 +0,0 @@
/*
* Lockless get_user_pages_fast for x86
*
* Copyright (C) 2008 Nick Piggin
* Copyright (C) 2008 Novell Inc.
*/
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/vmstat.h>
#include <linux/highmem.h>
#include <linux/swap.h>
#include <linux/memremap.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
static inline pte_t gup_get_pte(pte_t *ptep)
{
#ifndef CONFIG_X86_PAE
return READ_ONCE(*ptep);
#else
/*
* With get_user_pages_fast, we walk down the pagetables without taking
* any locks. For this we would like to load the pointers atomically,
* but that is not possible (without expensive cmpxchg8b) on PAE. What
* we do have is the guarantee that a pte will only either go from not
* present to present, or present to not present or both -- it will not
* switch to a completely different present page without a TLB flush in
* between; something that we are blocking by holding interrupts off.
*
* Setting ptes from not present to present goes:
* ptep->pte_high = h;
* smp_wmb();
* ptep->pte_low = l;
*
* And present to not present goes:
* ptep->pte_low = 0;
* smp_wmb();
* ptep->pte_high = 0;
*
* We must ensure here that the load of pte_low sees l iff pte_high
* sees h. We load pte_high *after* loading pte_low, which ensures we
* don't see an older value of pte_high. *Then* we recheck pte_low,
* which ensures that we haven't picked up a changed pte high. We might
* have got rubbish values from pte_low and pte_high, but we are
* guaranteed that pte_low will not have the present bit set *unless*
* it is 'l'. And get_user_pages_fast only operates on present ptes, so
* we're safe.
*
* gup_get_pte should not be used or copied outside gup.c without being
* very careful -- it does not atomically load the pte or anything that
* is likely to be useful for you.
*/
pte_t pte;
retry:
pte.pte_low = ptep->pte_low;
smp_rmb();
pte.pte_high = ptep->pte_high;
smp_rmb();
if (unlikely(pte.pte_low != ptep->pte_low))
goto retry;
return pte;
#endif
}
static void undo_dev_pagemap(int *nr, int nr_start, struct page **pages)
{
while ((*nr) - nr_start) {
struct page *page = pages[--(*nr)];
ClearPageReferenced(page);
put_page(page);
}
}
/*
* 'pteval' can come from a pte, pmd, pud or p4d. We only check
* _PAGE_PRESENT, _PAGE_USER, and _PAGE_RW in here which are the
* same value on all 4 types.
*/
static inline int pte_allows_gup(unsigned long pteval, int write)
{
unsigned long need_pte_bits = _PAGE_PRESENT|_PAGE_USER;
if (write)
need_pte_bits |= _PAGE_RW;
if ((pteval & need_pte_bits) != need_pte_bits)
return 0;
/* Check memory protection keys permissions. */
if (!__pkru_allows_pkey(pte_flags_pkey(pteval), write))
return 0;
return 1;
}
/*
* The performance critical leaf functions are made noinline otherwise gcc
* inlines everything into a single function which results in too much
* register pressure.
*/
static noinline int gup_pte_range(pmd_t pmd, unsigned long addr,
unsigned long end, int write, struct page **pages, int *nr)
{
struct dev_pagemap *pgmap = NULL;
int nr_start = *nr, ret = 0;
pte_t *ptep, *ptem;
/*
* Keep the original mapped PTE value (ptem) around since we
* might increment ptep off the end of the page when finishing
* our loop iteration.
*/
ptem = ptep = pte_offset_map(&pmd, addr);
do {
pte_t pte = gup_get_pte(ptep);
struct page *page;
/* Similar to the PMD case, NUMA hinting must take slow path */
if (pte_protnone(pte))
break;
if (!pte_allows_gup(pte_val(pte), write))
break;
if (pte_devmap(pte)) {
pgmap = get_dev_pagemap(pte_pfn(pte), pgmap);
if (unlikely(!pgmap)) {
undo_dev_pagemap(nr, nr_start, pages);
break;
}
} else if (pte_special(pte))
break;
VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
page = pte_page(pte);
get_page(page);
put_dev_pagemap(pgmap);
SetPageReferenced(page);
pages[*nr] = page;
(*nr)++;
} while (ptep++, addr += PAGE_SIZE, addr != end);
if (addr == end)
ret = 1;
pte_unmap(ptem);
return ret;
}
static inline void get_head_page_multiple(struct page *page, int nr)
{
VM_BUG_ON_PAGE(page != compound_head(page), page);
VM_BUG_ON_PAGE(page_count(page) == 0, page);
page_ref_add(page, nr);
SetPageReferenced(page);
}
static int __gup_device_huge(unsigned long pfn, unsigned long addr,
unsigned long end, struct page **pages, int *nr)
{
int nr_start = *nr;
struct dev_pagemap *pgmap = NULL;
do {
struct page *page = pfn_to_page(pfn);
pgmap = get_dev_pagemap(pfn, pgmap);
if (unlikely(!pgmap)) {
undo_dev_pagemap(nr, nr_start, pages);
return 0;
}
SetPageReferenced(page);
pages[*nr] = page;
get_page(page);
put_dev_pagemap(pgmap);
(*nr)++;
pfn++;
} while (addr += PAGE_SIZE, addr != end);
return 1;
}
static int __gup_device_huge_pmd(pmd_t pmd, unsigned long addr,
unsigned long end, struct page **pages, int *nr)
{
unsigned long fault_pfn;
fault_pfn = pmd_pfn(pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
return __gup_device_huge(fault_pfn, addr, end, pages, nr);
}
static int __gup_device_huge_pud(pud_t pud, unsigned long addr,
unsigned long end, struct page **pages, int *nr)
{
unsigned long fault_pfn;
fault_pfn = pud_pfn(pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
return __gup_device_huge(fault_pfn, addr, end, pages, nr);
}
static noinline int gup_huge_pmd(pmd_t pmd, unsigned long addr,
unsigned long end, int write, struct page **pages, int *nr)
{
struct page *head, *page;
int refs;
if (!pte_allows_gup(pmd_val(pmd), write))
return 0;
VM_BUG_ON(!pfn_valid(pmd_pfn(pmd)));
if (pmd_devmap(pmd))
return __gup_device_huge_pmd(pmd, addr, end, pages, nr);
/* hugepages are never "special" */
VM_BUG_ON(pmd_flags(pmd) & _PAGE_SPECIAL);
refs = 0;
head = pmd_page(pmd);
page = head + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
do {
VM_BUG_ON_PAGE(compound_head(page) != head, page);
pages[*nr] = page;
(*nr)++;
page++;
refs++;
} while (addr += PAGE_SIZE, addr != end);
get_head_page_multiple(head, refs);
return 1;
}
static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
int write, struct page **pages, int *nr)
{
unsigned long next;
pmd_t *pmdp;
pmdp = pmd_offset(&pud, addr);
do {
pmd_t pmd = *pmdp;
next = pmd_addr_end(addr, end);
if (pmd_none(pmd))
return 0;
if (unlikely(pmd_large(pmd) || !pmd_present(pmd))) {
/*
* NUMA hinting faults need to be handled in the GUP
* slowpath for accounting purposes and so that they
* can be serialised against THP migration.
*/
if (pmd_protnone(pmd))
return 0;
if (!gup_huge_pmd(pmd, addr, next, write, pages, nr))
return 0;
} else {
if (!gup_pte_range(pmd, addr, next, write, pages, nr))
return 0;
}
} while (pmdp++, addr = next, addr != end);
return 1;
}
static noinline int gup_huge_pud(pud_t pud, unsigned long addr,
unsigned long end, int write, struct page **pages, int *nr)
{
struct page *head, *page;
int refs;
if (!pte_allows_gup(pud_val(pud), write))
return 0;
VM_BUG_ON(!pfn_valid(pud_pfn(pud)));
if (pud_devmap(pud))
return __gup_device_huge_pud(pud, addr, end, pages, nr);
/* hugepages are never "special" */
VM_BUG_ON(pud_flags(pud) & _PAGE_SPECIAL);
refs = 0;
head = pud_page(pud);
page = head + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
do {
VM_BUG_ON_PAGE(compound_head(page) != head, page);
pages[*nr] = page;
(*nr)++;
page++;
refs++;
} while (addr += PAGE_SIZE, addr != end);
get_head_page_multiple(head, refs);
return 1;
}
static int gup_pud_range(p4d_t p4d, unsigned long addr, unsigned long end,
int write, struct page **pages, int *nr)
{
unsigned long next;
pud_t *pudp;
pudp = pud_offset(&p4d, addr);
do {
pud_t pud = *pudp;
next = pud_addr_end(addr, end);
if (pud_none(pud))
return 0;
if (unlikely(pud_large(pud))) {
if (!gup_huge_pud(pud, addr, next, write, pages, nr))
return 0;
} else {
if (!gup_pmd_range(pud, addr, next, write, pages, nr))
return 0;
}
} while (pudp++, addr = next, addr != end);
return 1;
}
static int gup_p4d_range(pgd_t pgd, unsigned long addr, unsigned long end,
int write, struct page **pages, int *nr)
{
unsigned long next;
p4d_t *p4dp;
p4dp = p4d_offset(&pgd, addr);
do {
p4d_t p4d = *p4dp;
next = p4d_addr_end(addr, end);
if (p4d_none(p4d))
return 0;
BUILD_BUG_ON(p4d_large(p4d));
if (!gup_pud_range(p4d, addr, next, write, pages, nr))
return 0;
} while (p4dp++, addr = next, addr != end);
return 1;
}
/*
* Like get_user_pages_fast() except its IRQ-safe in that it won't fall
* back to the regular GUP.
*/
int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
struct page **pages)
{
struct mm_struct *mm = current->mm;
unsigned long addr, len, end;
unsigned long next;
unsigned long flags;
pgd_t *pgdp;
int nr = 0;
start &= PAGE_MASK;
addr = start;
len = (unsigned long) nr_pages << PAGE_SHIFT;
end = start + len;
if (unlikely(!access_ok(write ? VERIFY_WRITE : VERIFY_READ,
(void __user *)start, len)))
return 0;
/*
* XXX: batch / limit 'nr', to avoid large irq off latency
* needs some instrumenting to determine the common sizes used by
* important workloads (eg. DB2), and whether limiting the batch size
* will decrease performance.
*
* It seems like we're in the clear for the moment. Direct-IO is
* the main guy that batches up lots of get_user_pages, and even
* they are limited to 64-at-a-time which is not so many.
*/
/*
* This doesn't prevent pagetable teardown, but does prevent
* the pagetables and pages from being freed on x86.
*
* So long as we atomically load page table pointers versus teardown
* (which we do on x86, with the above PAE exception), we can follow the
* address down to the the page and take a ref on it.
*/
local_irq_save(flags);
pgdp = pgd_offset(mm, addr);
do {
pgd_t pgd = *pgdp;
next = pgd_addr_end(addr, end);
if (pgd_none(pgd))
break;
if (!gup_p4d_range(pgd, addr, next, write, pages, &nr))
break;
} while (pgdp++, addr = next, addr != end);
local_irq_restore(flags);
return nr;
}
/**
* get_user_pages_fast() - pin user pages in memory
* @start: starting user address
* @nr_pages: number of pages from start to pin
* @write: whether pages will be written to
* @pages: array that receives pointers to the pages pinned.
* Should be at least nr_pages long.
*
* Attempt to pin user pages in memory without taking mm->mmap_sem.
* If not successful, it will fall back to taking the lock and
* calling get_user_pages().
*
* Returns number of pages pinned. This may be fewer than the number
* requested. If nr_pages is 0 or negative, returns 0. If no pages
* were pinned, returns -errno.
*/
int get_user_pages_fast(unsigned long start, int nr_pages, int write,
struct page **pages)
{
struct mm_struct *mm = current->mm;
unsigned long addr, len, end;
unsigned long next;
pgd_t *pgdp;
int nr = 0;
start &= PAGE_MASK;
addr = start;
len = (unsigned long) nr_pages << PAGE_SHIFT;
end = start + len;
if (end < start)
goto slow_irqon;
#ifdef CONFIG_X86_64
if (end >> __VIRTUAL_MASK_SHIFT)
goto slow_irqon;
#endif
/*
* XXX: batch / limit 'nr', to avoid large irq off latency
* needs some instrumenting to determine the common sizes used by
* important workloads (eg. DB2), and whether limiting the batch size
* will decrease performance.
*
* It seems like we're in the clear for the moment. Direct-IO is
* the main guy that batches up lots of get_user_pages, and even
* they are limited to 64-at-a-time which is not so many.
*/
/*
* This doesn't prevent pagetable teardown, but does prevent
* the pagetables and pages from being freed on x86.
*
* So long as we atomically load page table pointers versus teardown
* (which we do on x86, with the above PAE exception), we can follow the
* address down to the the page and take a ref on it.
*/
local_irq_disable();
pgdp = pgd_offset(mm, addr);
do {
pgd_t pgd = *pgdp;
next = pgd_addr_end(addr, end);
if (pgd_none(pgd))
goto slow;
if (!gup_p4d_range(pgd, addr, next, write, pages, &nr))
goto slow;
} while (pgdp++, addr = next, addr != end);
local_irq_enable();
VM_BUG_ON(nr != (end - start) >> PAGE_SHIFT);
return nr;
{
int ret;
slow:
local_irq_enable();
slow_irqon:
/* Try to get the remaining pages with get_user_pages */
start += nr << PAGE_SHIFT;
pages += nr;
ret = get_user_pages_unlocked(start,
(end - start) >> PAGE_SHIFT,
pages, write ? FOLL_WRITE : 0);
/* Have to be a bit careful with return values */
if (nr > 0) {
if (ret < 0)
ret = nr;
else
ret += nr;
}
return ret;
}
}

4
arch/x86/mm/init.c
View File

@ -811,10 +811,8 @@ void __init zone_sizes_init(void)
}
DEFINE_PER_CPU_SHARED_ALIGNED(struct tlb_state, cpu_tlbstate) = {
#ifdef CONFIG_SMP
.active_mm = &init_mm,
.loaded_mm = &init_mm,
.state = 0,
#endif
.cr4 = ~0UL, /* fail hard if we screw up cr4 shadow initialization */
};
EXPORT_SYMBOL_GPL(cpu_tlbstate);

108
arch/x86/mm/init_64.c
View File

@ -92,6 +92,44 @@ __setup("noexec32=", nonx32_setup);
* When memory was added make sure all the processes MM have
* suitable PGD entries in the local PGD level page.
*/
#ifdef CONFIG_X86_5LEVEL
void sync_global_pgds(unsigned long start, unsigned long end)
{
unsigned long addr;
for (addr = start; addr <= end; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
const pgd_t *pgd_ref = pgd_offset_k(addr);
struct page *page;
/* Check for overflow */
if (addr < start)
break;
if (pgd_none(*pgd_ref))
continue;
spin_lock(&pgd_lock);
list_for_each_entry(page, &pgd_list, lru) {
pgd_t *pgd;
spinlock_t *pgt_lock;
pgd = (pgd_t *)page_address(page) + pgd_index(addr);
/* the pgt_lock only for Xen */
pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
spin_lock(pgt_lock);
if (!pgd_none(*pgd_ref) && !pgd_none(*pgd))
BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
if (pgd_none(*pgd))
set_pgd(pgd, *pgd_ref);
spin_unlock(pgt_lock);
}
spin_unlock(&pgd_lock);
}
}
#else
void sync_global_pgds(unsigned long start, unsigned long end)
{
unsigned long addr;
@ -135,6 +173,7 @@ void sync_global_pgds(unsigned long start, unsigned long end)
spin_unlock(&pgd_lock);
}
}
#endif
/*
* NOTE: This function is marked __ref because it calls __init function
@ -585,6 +624,57 @@ phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
return paddr_last;
}
static unsigned long __meminit
phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end,
unsigned long page_size_mask)
{
unsigned long paddr_next, paddr_last = paddr_end;
unsigned long vaddr = (unsigned long)__va(paddr);
int i = p4d_index(vaddr);
if (!IS_ENABLED(CONFIG_X86_5LEVEL))
return phys_pud_init((pud_t *) p4d_page, paddr, paddr_end, page_size_mask);
for (; i < PTRS_PER_P4D; i++, paddr = paddr_next) {
p4d_t *p4d;
pud_t *pud;
vaddr = (unsigned long)__va(paddr);
p4d = p4d_page + p4d_index(vaddr);
paddr_next = (paddr & P4D_MASK) + P4D_SIZE;
if (paddr >= paddr_end) {
if (!after_bootmem &&
!e820__mapped_any(paddr & P4D_MASK, paddr_next,
E820_TYPE_RAM) &&
!e820__mapped_any(paddr & P4D_MASK, paddr_next,
E820_TYPE_RESERVED_KERN))
set_p4d(p4d, __p4d(0));
continue;
}
if (!p4d_none(*p4d)) {
pud = pud_offset(p4d, 0);
paddr_last = phys_pud_init(pud, paddr,
paddr_end,
page_size_mask);
__flush_tlb_all();
continue;
}
pud = alloc_low_page();
paddr_last = phys_pud_init(pud, paddr, paddr_end,
page_size_mask);
spin_lock(&init_mm.page_table_lock);
p4d_populate(&init_mm, p4d, pud);
spin_unlock(&init_mm.page_table_lock);
}
__flush_tlb_all();
return paddr_last;
}
/*
* Create page table mapping for the physical memory for specific physical
* addresses. The virtual and physical addresses have to be aligned on PMD level
@ -606,26 +696,26 @@ kernel_physical_mapping_init(unsigned long paddr_start,
for (; vaddr < vaddr_end; vaddr = vaddr_next) {
pgd_t *pgd = pgd_offset_k(vaddr);
p4d_t *p4d;
pud_t *pud;
vaddr_next = (vaddr & PGDIR_MASK) + PGDIR_SIZE;
BUILD_BUG_ON(pgd_none(*pgd));
p4d = p4d_offset(pgd, vaddr);
if (p4d_val(*p4d)) {
pud = (pud_t *)p4d_page_vaddr(*p4d);
paddr_last = phys_pud_init(pud, __pa(vaddr),
if (pgd_val(*pgd)) {
p4d = (p4d_t *)pgd_page_vaddr(*pgd);
paddr_last = phys_p4d_init(p4d, __pa(vaddr),
__pa(vaddr_end),
page_size_mask);
continue;
}
pud = alloc_low_page();
paddr_last = phys_pud_init(pud, __pa(vaddr), __pa(vaddr_end),
p4d = alloc_low_page();
paddr_last = phys_p4d_init(p4d, __pa(vaddr), __pa(vaddr_end),
page_size_mask);
spin_lock(&init_mm.page_table_lock);
p4d_populate(&init_mm, p4d, pud);
if (IS_ENABLED(CONFIG_X86_5LEVEL))
pgd_populate(&init_mm, pgd, p4d);
else
p4d_populate(&init_mm, p4d_offset(pgd, vaddr), (pud_t *) p4d);
spin_unlock(&init_mm.page_table_lock);
pgd_changed = true;
}

2
arch/x86/mm/ioremap.c
View File

@ -424,7 +424,7 @@ static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss;
static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
{
/* Don't assume we're using swapper_pg_dir at this point */
pgd_t *base = __va(read_cr3());
pgd_t *base = __va(read_cr3_pa());
pgd_t *pgd = &base[pgd_index(addr)];
p4d_t *p4d = p4d_offset(pgd, addr);
pud_t *pud = pud_offset(p4d, addr);

12
arch/x86/mm/kasan_init_64.c
View File

@ -12,7 +12,7 @@
#include <asm/tlbflush.h>
#include <asm/sections.h>
extern pgd_t early_level4_pgt[PTRS_PER_PGD];
extern pgd_t early_top_pgt[PTRS_PER_PGD];
extern struct range pfn_mapped[E820_MAX_ENTRIES];
static int __init map_range(struct range *range)
@ -109,8 +109,8 @@ void __init kasan_early_init(void)
for (i = 0; CONFIG_PGTABLE_LEVELS >= 5 && i < PTRS_PER_P4D; i++)
kasan_zero_p4d[i] = __p4d(p4d_val);
kasan_map_early_shadow(early_level4_pgt);
kasan_map_early_shadow(init_level4_pgt);
kasan_map_early_shadow(early_top_pgt);
kasan_map_early_shadow(init_top_pgt);
}
void __init kasan_init(void)
@ -121,8 +121,8 @@ void __init kasan_init(void)
register_die_notifier(&kasan_die_notifier);
#endif
memcpy(early_level4_pgt, init_level4_pgt, sizeof(early_level4_pgt));
load_cr3(early_level4_pgt);
memcpy(early_top_pgt, init_top_pgt, sizeof(early_top_pgt));
load_cr3(early_top_pgt);
__flush_tlb_all();
clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END);
@ -148,7 +148,7 @@ void __init kasan_init(void)
kasan_populate_zero_shadow(kasan_mem_to_shadow((void *)MODULES_END),
(void *)KASAN_SHADOW_END);
load_cr3(init_level4_pgt);
load_cr3(init_top_pgt);
__flush_tlb_all();
/*

81
arch/x86/mm/kaslr.c
View File

@ -6,12 +6,12 @@
*
* Entropy is generated using the KASLR early boot functions now shared in
* the lib directory (originally written by Kees Cook). Randomization is
* done on PGD & PUD page table levels to increase possible addresses. The
* physical memory mapping code was adapted to support PUD level virtual
* addresses. This implementation on the best configuration provides 30,000
* possible virtual addresses in average for each memory region. An additional
* low memory page is used to ensure each CPU can start with a PGD aligned
* virtual address (for realmode).
* done on PGD & P4D/PUD page table levels to increase possible addresses.
* The physical memory mapping code was adapted to support P4D/PUD level
* virtual addresses. This implementation on the best configuration provides
* 30,000 possible virtual addresses in average for each memory region.
* An additional low memory page is used to ensure each CPU can start with
* a PGD aligned virtual address (for realmode).
*
* The order of each memory region is not changed. The feature looks at
* the available space for the regions based on different configuration
@ -70,7 +70,7 @@ static __initdata struct kaslr_memory_region {
unsigned long *base;
unsigned long size_tb;
} kaslr_regions[] = {
{ &page_offset_base, 64/* Maximum */ },
{ &page_offset_base, 1 << (__PHYSICAL_MASK_SHIFT - TB_SHIFT) /* Maximum */ },
{ &vmalloc_base, VMALLOC_SIZE_TB },
{ &vmemmap_base, 1 },
};
@ -142,7 +142,10 @@ void __init kernel_randomize_memory(void)
*/
entropy = remain_entropy / (ARRAY_SIZE(kaslr_regions) - i);
prandom_bytes_state(&rand_state, &rand, sizeof(rand));
entropy = (rand % (entropy + 1)) & PUD_MASK;
if (IS_ENABLED(CONFIG_X86_5LEVEL))
entropy = (rand % (entropy + 1)) & P4D_MASK;
else
entropy = (rand % (entropy + 1)) & PUD_MASK;
vaddr += entropy;
*kaslr_regions[i].base = vaddr;
@ -151,27 +154,21 @@ void __init kernel_randomize_memory(void)
* randomization alignment.
*/
vaddr += get_padding(&kaslr_regions[i]);
vaddr = round_up(vaddr + 1, PUD_SIZE);
if (IS_ENABLED(CONFIG_X86_5LEVEL))
vaddr = round_up(vaddr + 1, P4D_SIZE);
else
vaddr = round_up(vaddr + 1, PUD_SIZE);
remain_entropy -= entropy;
}
}
/*
* Create PGD aligned trampoline table to allow real mode initialization
* of additional CPUs. Consume only 1 low memory page.
*/
void __meminit init_trampoline(void)
static void __meminit init_trampoline_pud(void)
{
unsigned long paddr, paddr_next;
pgd_t *pgd;
pud_t *pud_page, *pud_page_tramp;
int i;
if (!kaslr_memory_enabled()) {
init_trampoline_default();
return;
}
pud_page_tramp = alloc_low_page();
paddr = 0;
@ -192,3 +189,49 @@ void __meminit init_trampoline(void)
set_pgd(&trampoline_pgd_entry,
__pgd(_KERNPG_TABLE | __pa(pud_page_tramp)));
}
static void __meminit init_trampoline_p4d(void)
{
unsigned long paddr, paddr_next;
pgd_t *pgd;
p4d_t *p4d_page, *p4d_page_tramp;
int i;
p4d_page_tramp = alloc_low_page();
paddr = 0;
pgd = pgd_offset_k((unsigned long)__va(paddr));
p4d_page = (p4d_t *) pgd_page_vaddr(*pgd);
for (i = p4d_index(paddr); i < PTRS_PER_P4D; i++, paddr = paddr_next) {
p4d_t *p4d, *p4d_tramp;
unsigned long vaddr = (unsigned long)__va(paddr);
p4d_tramp = p4d_page_tramp + p4d_index(paddr);
p4d = p4d_page + p4d_index(vaddr);
paddr_next = (paddr & P4D_MASK) + P4D_SIZE;
*p4d_tramp = *p4d;
}
set_pgd(&trampoline_pgd_entry,
__pgd(_KERNPG_TABLE | __pa(p4d_page_tramp)));
}
/*
* Create PGD aligned trampoline table to allow real mode initialization
* of additional CPUs. Consume only 1 low memory page.
*/
void __meminit init_trampoline(void)
{
if (!kaslr_memory_enabled()) {
init_trampoline_default();
return;
}
if (IS_ENABLED(CONFIG_X86_5LEVEL))
init_trampoline_p4d();
else
init_trampoline_pud();
}

3
arch/x86/mm/mmap.c
View File

@ -74,9 +74,6 @@ static int mmap_is_legacy(void)
if (current->personality & ADDR_COMPAT_LAYOUT)
return 1;
if (rlimit(RLIMIT_STACK) == RLIM_INFINITY)
return 1;
return sysctl_legacy_va_layout;
}

478
arch/x86/mm/tlb.c
View File

@ -15,7 +15,7 @@
#include <linux/debugfs.h>
/*
* Smarter SMP flushing macros.
* TLB flushing, formerly SMP-only
* c/o Linus Torvalds.
*
* These mean you can really definitely utterly forget about
@ -28,39 +28,28 @@
* Implement flush IPI by CALL_FUNCTION_VECTOR, Alex Shi
*/
#ifdef CONFIG_SMP
struct flush_tlb_info {
struct mm_struct *flush_mm;
unsigned long flush_start;
unsigned long flush_end;
};
/*
* We cannot call mmdrop() because we are in interrupt context,
* instead update mm->cpu_vm_mask.
*/
void leave_mm(int cpu)
{
struct mm_struct *active_mm = this_cpu_read(cpu_tlbstate.active_mm);
struct mm_struct *loaded_mm = this_cpu_read(cpu_tlbstate.loaded_mm);
/*
* It's plausible that we're in lazy TLB mode while our mm is init_mm.
* If so, our callers still expect us to flush the TLB, but there
* aren't any user TLB entries in init_mm to worry about.
*
* This needs to happen before any other sanity checks due to
* intel_idle's shenanigans.
*/
if (loaded_mm == &init_mm)
return;
if (this_cpu_read(cpu_tlbstate.state) == TLBSTATE_OK)
BUG();
if (cpumask_test_cpu(cpu, mm_cpumask(active_mm))) {
cpumask_clear_cpu(cpu, mm_cpumask(active_mm));
load_cr3(swapper_pg_dir);
/*
* This gets called in the idle path where RCU
* functions differently. Tracing normally
* uses RCU, so we have to call the tracepoint
* specially here.
*/
trace_tlb_flush_rcuidle(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL);
}
switch_mm(NULL, &init_mm, NULL);
}
EXPORT_SYMBOL_GPL(leave_mm);
#endif /* CONFIG_SMP */
void switch_mm(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk)
{
@ -75,216 +64,167 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk)
{
unsigned cpu = smp_processor_id();
struct mm_struct *real_prev = this_cpu_read(cpu_tlbstate.loaded_mm);
if (likely(prev != next)) {
if (IS_ENABLED(CONFIG_VMAP_STACK)) {
/*
* If our current stack is in vmalloc space and isn't
* mapped in the new pgd, we'll double-fault. Forcibly
* map it.
*/
unsigned int stack_pgd_index = pgd_index(current_stack_pointer());
/*
* NB: The scheduler will call us with prev == next when
* switching from lazy TLB mode to normal mode if active_mm
* isn't changing. When this happens, there is no guarantee
* that CR3 (and hence cpu_tlbstate.loaded_mm) matches next.
*
* NB: leave_mm() calls us with prev == NULL and tsk == NULL.
*/
pgd_t *pgd = next->pgd + stack_pgd_index;
if (unlikely(pgd_none(*pgd)))
set_pgd(pgd, init_mm.pgd[stack_pgd_index]);
}
#ifdef CONFIG_SMP
this_cpu_write(cpu_tlbstate.state, TLBSTATE_OK);
this_cpu_write(cpu_tlbstate.active_mm, next);
#endif
cpumask_set_cpu(cpu, mm_cpumask(next));
this_cpu_write(cpu_tlbstate.state, TLBSTATE_OK);
if (real_prev == next) {
/*
* Re-load page tables.
*
* This logic has an ordering constraint:
*
* CPU 0: Write to a PTE for 'next'
* CPU 0: load bit 1 in mm_cpumask. if nonzero, send IPI.
* CPU 1: set bit 1 in next's mm_cpumask
* CPU 1: load from the PTE that CPU 0 writes (implicit)
*
* We need to prevent an outcome in which CPU 1 observes
* the new PTE value and CPU 0 observes bit 1 clear in
* mm_cpumask. (If that occurs, then the IPI will never
* be sent, and CPU 0's TLB will contain a stale entry.)
*
* The bad outcome can occur if either CPU's load is
* reordered before that CPU's store, so both CPUs must
* execute full barriers to prevent this from happening.
*
* Thus, switch_mm needs a full barrier between the
* store to mm_cpumask and any operation that could load
* from next->pgd. TLB fills are special and can happen
* due to instruction fetches or for no reason at all,
* and neither LOCK nor MFENCE orders them.
* Fortunately, load_cr3() is serializing and gives the
* ordering guarantee we need.
*
* There's nothing to do: we always keep the per-mm control
* regs in sync with cpu_tlbstate.loaded_mm. Just
* sanity-check mm_cpumask.
*/
load_cr3(next->pgd);
trace_tlb_flush(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL);
/* Stop flush ipis for the previous mm */
cpumask_clear_cpu(cpu, mm_cpumask(prev));
/* Load per-mm CR4 state */
load_mm_cr4(next);
#ifdef CONFIG_MODIFY_LDT_SYSCALL
/*
* Load the LDT, if the LDT is different.
*
* It's possible that prev->context.ldt doesn't match
* the LDT register. This can happen if leave_mm(prev)
* was called and then modify_ldt changed
* prev->context.ldt but suppressed an IPI to this CPU.
* In this case, prev->context.ldt != NULL, because we
* never set context.ldt to NULL while the mm still
* exists. That means that next->context.ldt !=
* prev->context.ldt, because mms never share an LDT.
*/
if (unlikely(prev->context.ldt != next->context.ldt))
load_mm_ldt(next);
#endif
}
#ifdef CONFIG_SMP
else {
this_cpu_write(cpu_tlbstate.state, TLBSTATE_OK);
BUG_ON(this_cpu_read(cpu_tlbstate.active_mm) != next);
if (!cpumask_test_cpu(cpu, mm_cpumask(next))) {
/*
* On established mms, the mm_cpumask is only changed
* from irq context, from ptep_clear_flush() while in
* lazy tlb mode, and here. Irqs are blocked during
* schedule, protecting us from simultaneous changes.
*/
if (WARN_ON_ONCE(!cpumask_test_cpu(cpu, mm_cpumask(next))))
cpumask_set_cpu(cpu, mm_cpumask(next));
/*
* We were in lazy tlb mode and leave_mm disabled
* tlb flush IPI delivery. We must reload CR3
* to make sure to use no freed page tables.
*
* As above, load_cr3() is serializing and orders TLB
* fills with respect to the mm_cpumask write.
*/
load_cr3(next->pgd);
trace_tlb_flush(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL);
load_mm_cr4(next);
load_mm_ldt(next);
}
return;
}
#endif
if (IS_ENABLED(CONFIG_VMAP_STACK)) {
/*
* If our current stack is in vmalloc space and isn't
* mapped in the new pgd, we'll double-fault. Forcibly
* map it.
*/
unsigned int stack_pgd_index = pgd_index(current_stack_pointer());
pgd_t *pgd = next->pgd + stack_pgd_index;
if (unlikely(pgd_none(*pgd)))
set_pgd(pgd, init_mm.pgd[stack_pgd_index]);
}
this_cpu_write(cpu_tlbstate.loaded_mm, next);
WARN_ON_ONCE(cpumask_test_cpu(cpu, mm_cpumask(next)));
cpumask_set_cpu(cpu, mm_cpumask(next));
/*
* Re-load page tables.
*
* This logic has an ordering constraint:
*
* CPU 0: Write to a PTE for 'next'
* CPU 0: load bit 1 in mm_cpumask. if nonzero, send IPI.
* CPU 1: set bit 1 in next's mm_cpumask
* CPU 1: load from the PTE that CPU 0 writes (implicit)
*
* We need to prevent an outcome in which CPU 1 observes
* the new PTE value and CPU 0 observes bit 1 clear in
* mm_cpumask. (If that occurs, then the IPI will never
* be sent, and CPU 0's TLB will contain a stale entry.)
*
* The bad outcome can occur if either CPU's load is
* reordered before that CPU's store, so both CPUs must
* execute full barriers to prevent this from happening.
*
* Thus, switch_mm needs a full barrier between the
* store to mm_cpumask and any operation that could load
* from next->pgd. TLB fills are special and can happen
* due to instruction fetches or for no reason at all,
* and neither LOCK nor MFENCE orders them.
* Fortunately, load_cr3() is serializing and gives the
* ordering guarantee we need.
*/
load_cr3(next->pgd);
/*
* This gets called via leave_mm() in the idle path where RCU
* functions differently. Tracing normally uses RCU, so we have to
* call the tracepoint specially here.
*/
trace_tlb_flush_rcuidle(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL);
/* Stop flush ipis for the previous mm */
WARN_ON_ONCE(!cpumask_test_cpu(cpu, mm_cpumask(real_prev)) &&
real_prev != &init_mm);
cpumask_clear_cpu(cpu, mm_cpumask(real_prev));
/* Load per-mm CR4 and LDTR state */
load_mm_cr4(next);
switch_ldt(real_prev, next);
}
#ifdef CONFIG_SMP
/*
* The flush IPI assumes that a thread switch happens in this order:
* [cpu0: the cpu that switches]
* 1) switch_mm() either 1a) or 1b)
* 1a) thread switch to a different mm
* 1a1) set cpu_tlbstate to TLBSTATE_OK
* Now the tlb flush NMI handler flush_tlb_func won't call leave_mm
* if cpu0 was in lazy tlb mode.
* 1a2) update cpu active_mm
* Now cpu0 accepts tlb flushes for the new mm.
* 1a3) cpu_set(cpu, new_mm->cpu_vm_mask);
* Now the other cpus will send tlb flush ipis.
* 1a4) change cr3.
* 1a5) cpu_clear(cpu, old_mm->cpu_vm_mask);
* Stop ipi delivery for the old mm. This is not synchronized with
* the other cpus, but flush_tlb_func ignore flush ipis for the wrong
* mm, and in the worst case we perform a superfluous tlb flush.
* 1b) thread switch without mm change
* cpu active_mm is correct, cpu0 already handles flush ipis.
* 1b1) set cpu_tlbstate to TLBSTATE_OK
* 1b2) test_and_set the cpu bit in cpu_vm_mask.
* Atomically set the bit [other cpus will start sending flush ipis],
* and test the bit.
* 1b3) if the bit was 0: leave_mm was called, flush the tlb.
* 2) switch %%esp, ie current
*
* The interrupt must handle 2 special cases:
* - cr3 is changed before %%esp, ie. it cannot use current->{active_,}mm.
* - the cpu performs speculative tlb reads, i.e. even if the cpu only
* runs in kernel space, the cpu could load tlb entries for user space
* pages.
*
* The good news is that cpu_tlbstate is local to each cpu, no
* write/read ordering problems.
*/
/*
* TLB flush funcation:
* 1) Flush the tlb entries if the cpu uses the mm that's being flushed.
* 2) Leave the mm if we are in the lazy tlb mode.
*/
static void flush_tlb_func(void *info)
static void flush_tlb_func_common(const struct flush_tlb_info *f,
bool local, enum tlb_flush_reason reason)
{
struct flush_tlb_info *f = info;
/* This code cannot presently handle being reentered. */
VM_WARN_ON(!irqs_disabled());
if (this_cpu_read(cpu_tlbstate.state) != TLBSTATE_OK) {
leave_mm(smp_processor_id());
return;
}
if (f->end == TLB_FLUSH_ALL) {
local_flush_tlb();
if (local)
count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
trace_tlb_flush(reason, TLB_FLUSH_ALL);
} else {
unsigned long addr;
unsigned long nr_pages = (f->end - f->start) >> PAGE_SHIFT;
addr = f->start;
while (addr < f->end) {
__flush_tlb_single(addr);
addr += PAGE_SIZE;
}
if (local)
count_vm_tlb_events(NR_TLB_LOCAL_FLUSH_ONE, nr_pages);
trace_tlb_flush(reason, nr_pages);
}
}
static void flush_tlb_func_local(void *info, enum tlb_flush_reason reason)
{
const struct flush_tlb_info *f = info;
flush_tlb_func_common(f, true, reason);
}
static void flush_tlb_func_remote(void *info)
{
const struct flush_tlb_info *f = info;
inc_irq_stat(irq_tlb_count);
if (f->flush_mm && f->flush_mm != this_cpu_read(cpu_tlbstate.active_mm))
if (f->mm && f->mm != this_cpu_read(cpu_tlbstate.loaded_mm))
return;
count_vm_tlb_event(NR_TLB_REMOTE_FLUSH_RECEIVED);
if (this_cpu_read(cpu_tlbstate.state) == TLBSTATE_OK) {
if (f->flush_end == TLB_FLUSH_ALL) {
local_flush_tlb();
trace_tlb_flush(TLB_REMOTE_SHOOTDOWN, TLB_FLUSH_ALL);
} else {
unsigned long addr;
unsigned long nr_pages =
(f->flush_end - f->flush_start) / PAGE_SIZE;
addr = f->flush_start;
while (addr < f->flush_end) {
__flush_tlb_single(addr);
addr += PAGE_SIZE;
}
trace_tlb_flush(TLB_REMOTE_SHOOTDOWN, nr_pages);
}
} else
leave_mm(smp_processor_id());
flush_tlb_func_common(f, false, TLB_REMOTE_SHOOTDOWN);
}
void native_flush_tlb_others(const struct cpumask *cpumask,
struct mm_struct *mm, unsigned long start,
unsigned long end)
const struct flush_tlb_info *info)
{
struct flush_tlb_info info;
info.flush_mm = mm;
info.flush_start = start;
info.flush_end = end;
count_vm_tlb_event(NR_TLB_REMOTE_FLUSH);
if (end == TLB_FLUSH_ALL)
if (info->end == TLB_FLUSH_ALL)
trace_tlb_flush(TLB_REMOTE_SEND_IPI, TLB_FLUSH_ALL);
else
trace_tlb_flush(TLB_REMOTE_SEND_IPI,
(end - start) >> PAGE_SHIFT);
(info->end - info->start) >> PAGE_SHIFT);
if (is_uv_system()) {
unsigned int cpu;
cpu = smp_processor_id();
cpumask = uv_flush_tlb_others(cpumask, mm, start, end, cpu);
cpumask = uv_flush_tlb_others(cpumask, info);
if (cpumask)
smp_call_function_many(cpumask, flush_tlb_func,
&info, 1);
smp_call_function_many(cpumask, flush_tlb_func_remote,
(void *)info, 1);
return;
}
smp_call_function_many(cpumask, flush_tlb_func, &info, 1);
smp_call_function_many(cpumask, flush_tlb_func_remote,
(void *)info, 1);
}
/*
@ -302,84 +242,40 @@ static unsigned long tlb_single_page_flush_ceiling __read_mostly = 33;
void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
unsigned long end, unsigned long vmflag)
{
unsigned long addr;
/* do a global flush by default */
unsigned long base_pages_to_flush = TLB_FLUSH_ALL;
int cpu;
preempt_disable();
struct flush_tlb_info info = {
.mm = mm,
};
if ((end != TLB_FLUSH_ALL) && !(vmflag & VM_HUGETLB))
base_pages_to_flush = (end - start) >> PAGE_SHIFT;
if (base_pages_to_flush > tlb_single_page_flush_ceiling)
base_pages_to_flush = TLB_FLUSH_ALL;
cpu = get_cpu();
if (current->active_mm != mm) {
/* Synchronize with switch_mm. */
smp_mb();
/* Synchronize with switch_mm. */
smp_mb();
goto out;
}
if (!current->mm) {
leave_mm(smp_processor_id());
/* Synchronize with switch_mm. */
smp_mb();
goto out;
}
/*
* Both branches below are implicit full barriers (MOV to CR or
* INVLPG) that synchronize with switch_mm.
*/
if (base_pages_to_flush == TLB_FLUSH_ALL) {
count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
local_flush_tlb();
/* Should we flush just the requested range? */
if ((end != TLB_FLUSH_ALL) &&
!(vmflag & VM_HUGETLB) &&
((end - start) >> PAGE_SHIFT) <= tlb_single_page_flush_ceiling) {
info.start = start;
info.end = end;
} else {
/* flush range by one by one 'invlpg' */
for (addr = start; addr < end; addr += PAGE_SIZE) {
count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ONE);
__flush_tlb_single(addr);
}
info.start = 0UL;
info.end = TLB_FLUSH_ALL;
}
trace_tlb_flush(TLB_LOCAL_MM_SHOOTDOWN, base_pages_to_flush);
out:
if (base_pages_to_flush == TLB_FLUSH_ALL) {
start = 0UL;
end = TLB_FLUSH_ALL;
if (mm == this_cpu_read(cpu_tlbstate.loaded_mm)) {
VM_WARN_ON(irqs_disabled());
local_irq_disable();
flush_tlb_func_local(&info, TLB_LOCAL_MM_SHOOTDOWN);
local_irq_enable();
}
if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids)
flush_tlb_others(mm_cpumask(mm), mm, start, end);
preempt_enable();
if (cpumask_any_but(mm_cpumask(mm), cpu) < nr_cpu_ids)
flush_tlb_others(mm_cpumask(mm), &info);
put_cpu();
}
void flush_tlb_page(struct vm_area_struct *vma, unsigned long start)
{
struct mm_struct *mm = vma->vm_mm;
preempt_disable();
if (current->active_mm == mm) {
if (current->mm) {
/*
* Implicit full barrier (INVLPG) that synchronizes
* with switch_mm.
*/
__flush_tlb_one(start);
} else {
leave_mm(smp_processor_id());
/* Synchronize with switch_mm. */
smp_mb();
}
}
if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids)
flush_tlb_others(mm_cpumask(mm), mm, start, start + PAGE_SIZE);
preempt_enable();
}
static void do_flush_tlb_all(void *info)
{
@ -401,7 +297,7 @@ static void do_kernel_range_flush(void *info)
unsigned long addr;
/* flush range by one by one 'invlpg' */
for (addr = f->flush_start; addr < f->flush_end; addr += PAGE_SIZE)
for (addr = f->start; addr < f->end; addr += PAGE_SIZE)
__flush_tlb_single(addr);
}
@ -410,16 +306,40 @@ void flush_tlb_kernel_range(unsigned long start, unsigned long end)
/* Balance as user space task's flush, a bit conservative */
if (end == TLB_FLUSH_ALL ||
(end - start) > tlb_single_page_flush_ceiling * PAGE_SIZE) {
(end - start) > tlb_single_page_flush_ceiling << PAGE_SHIFT) {
on_each_cpu(do_flush_tlb_all, NULL, 1);
} else {
struct flush_tlb_info info;
info.flush_start = start;
info.flush_end = end;
info.start = start;
info.end = end;
on_each_cpu(do_kernel_range_flush, &info, 1);
}
}
void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch)
{
struct flush_tlb_info info = {
.mm = NULL,
.start = 0UL,
.end = TLB_FLUSH_ALL,
};
int cpu = get_cpu();
if (cpumask_test_cpu(cpu, &batch->cpumask)) {
VM_WARN_ON(irqs_disabled());
local_irq_disable();
flush_tlb_func_local(&info, TLB_LOCAL_SHOOTDOWN);
local_irq_enable();
}
if (cpumask_any_but(&batch->cpumask, cpu) < nr_cpu_ids)
flush_tlb_others(&batch->cpumask, &info);
cpumask_clear(&batch->cpumask);
put_cpu();
}
static ssize_t tlbflush_read_file(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
@ -465,5 +385,3 @@ static int __init create_tlb_single_page_flush_ceiling(void)
return 0;
}
late_initcall(create_tlb_single_page_flush_ceiling);
#endif /* CONFIG_SMP */

4
arch/x86/platform/efi/efi_64.c
View File

@ -80,7 +80,7 @@ pgd_t * __init efi_call_phys_prolog(void)
int n_pgds, i, j;
if (!efi_enabled(EFI_OLD_MEMMAP)) {
save_pgd = (pgd_t *)read_cr3();
save_pgd = (pgd_t *)__read_cr3();
write_cr3((unsigned long)efi_scratch.efi_pgt);
goto out;
}
@ -649,7 +649,7 @@ efi_status_t efi_thunk_set_virtual_address_map(
efi_sync_low_kernel_mappings();
local_irq_save(flags);
efi_scratch.prev_cr3 = read_cr3();
efi_scratch.prev_cr3 = __read_cr3();
write_cr3((unsigned long)efi_scratch.efi_pgt);
__flush_tlb_all();

2
arch/x86/platform/olpc/olpc-xo1-pm.c
View File

@ -77,7 +77,7 @@ static int xo1_power_state_enter(suspend_state_t pm_state)
asmlinkage __visible int xo1_do_sleep(u8 sleep_state)
{
void *pgd_addr = __va(read_cr3());
void *pgd_addr = __va(read_cr3_pa());
/* Program wakeup mask (using dword access to CS5536_PM1_EN) */
outl(wakeup_mask << 16, acpi_base + CS5536_PM1_STS);

10
arch/x86/platform/uv/tlb_uv.c
View File

@ -1123,11 +1123,9 @@ static int set_distrib_bits(struct cpumask *flush_mask, struct bau_control *bcp,
* done. The returned pointer is valid till preemption is re-enabled.
*/
const struct cpumask *uv_flush_tlb_others(const struct cpumask *cpumask,
struct mm_struct *mm,
unsigned long start,
unsigned long end,
unsigned int cpu)
const struct flush_tlb_info *info)
{
unsigned int cpu = smp_processor_id();
int locals = 0, remotes = 0, hubs = 0;
struct bau_desc *bau_desc;
struct cpumask *flush_mask;
@ -1181,8 +1179,8 @@ const struct cpumask *uv_flush_tlb_others(const struct cpumask *cpumask,
record_send_statistics(stat, locals, hubs, remotes, bau_desc);
if (!end || (end - start) <= PAGE_SIZE)
address = start;
if (!info->end || (info->end - info->start) <= PAGE_SIZE)
address = info->start;
else
address = TLB_FLUSH_ALL;

2
arch/x86/power/cpu.c
View File

@ -129,7 +129,7 @@ static void __save_processor_state(struct saved_context *ctxt)
*/
ctxt->cr0 = read_cr0();
ctxt->cr2 = read_cr2();
ctxt->cr3 = read_cr3();
ctxt->cr3 = __read_cr3();
ctxt->cr4 = __read_cr4();
#ifdef CONFIG_X86_64
ctxt->cr8 = read_cr8();

3
arch/x86/power/hibernate_64.c
View File

@ -150,7 +150,8 @@ static int relocate_restore_code(void)
memcpy((void *)relocated_restore_code, &core_restore_code, PAGE_SIZE);
/* Make the page containing the relocated code executable */
pgd = (pgd_t *)__va(read_cr3()) + pgd_index(relocated_restore_code);
pgd = (pgd_t *)__va(read_cr3_pa()) +
pgd_index(relocated_restore_code);
p4d = p4d_offset(pgd, relocated_restore_code);
if (p4d_large(*p4d)) {
set_p4d(p4d, __p4d(p4d_val(*p4d) & ~_PAGE_NX));

2
arch/x86/realmode/init.c
View File

@ -102,7 +102,7 @@ static void __init setup_real_mode(void)
trampoline_pgd = (u64 *) __va(real_mode_header->trampoline_pgd);
trampoline_pgd[0] = trampoline_pgd_entry.pgd;
trampoline_pgd[511] = init_level4_pgt[511].pgd;
trampoline_pgd[511] = init_top_pgt[511].pgd;
#endif
}

83
arch/x86/xen/mmu_pv.c
View File

@ -975,37 +975,32 @@ static void xen_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
spin_unlock(&mm->page_table_lock);
}
#ifdef CONFIG_SMP
/* Another cpu may still have their %cr3 pointing at the pagetable, so
we need to repoint it somewhere else before we can unpin it. */
static void drop_other_mm_ref(void *info)
static void drop_mm_ref_this_cpu(void *info)
{
struct mm_struct *mm = info;
struct mm_struct *active_mm;
active_mm = this_cpu_read(cpu_tlbstate.active_mm);
if (active_mm == mm && this_cpu_read(cpu_tlbstate.state) != TLBSTATE_OK)
if (this_cpu_read(cpu_tlbstate.loaded_mm) == mm)
leave_mm(smp_processor_id());
/* If this cpu still has a stale cr3 reference, then make sure
it has been flushed. */
/*
* If this cpu still has a stale cr3 reference, then make sure
* it has been flushed.
*/
if (this_cpu_read(xen_current_cr3) == __pa(mm->pgd))
load_cr3(swapper_pg_dir);
xen_mc_flush();
}
#ifdef CONFIG_SMP
/*
* Another cpu may still have their %cr3 pointing at the pagetable, so
* we need to repoint it somewhere else before we can unpin it.
*/
static void xen_drop_mm_ref(struct mm_struct *mm)
{
cpumask_var_t mask;
unsigned cpu;
if (current->active_mm == mm) {
if (current->mm == mm)
load_cr3(swapper_pg_dir);
else
leave_mm(smp_processor_id());
}
drop_mm_ref_this_cpu(mm);
/* Get the "official" set of cpus referring to our pagetable. */
if (!alloc_cpumask_var(&mask, GFP_ATOMIC)) {
@ -1013,31 +1008,31 @@ static void xen_drop_mm_ref(struct mm_struct *mm)
if (!cpumask_test_cpu(cpu, mm_cpumask(mm))
&& per_cpu(xen_current_cr3, cpu) != __pa(mm->pgd))
continue;
smp_call_function_single(cpu, drop_other_mm_ref, mm, 1);
smp_call_function_single(cpu, drop_mm_ref_this_cpu, mm, 1);
}
return;
}
cpumask_copy(mask, mm_cpumask(mm));
/* It's possible that a vcpu may have a stale reference to our
cr3, because its in lazy mode, and it hasn't yet flushed
its set of pending hypercalls yet. In this case, we can
look at its actual current cr3 value, and force it to flush
if needed. */
/*
* It's possible that a vcpu may have a stale reference to our
* cr3, because its in lazy mode, and it hasn't yet flushed
* its set of pending hypercalls yet. In this case, we can
* look at its actual current cr3 value, and force it to flush
* if needed.
*/
for_each_online_cpu(cpu) {
if (per_cpu(xen_current_cr3, cpu) == __pa(mm->pgd))
cpumask_set_cpu(cpu, mask);
}
if (!cpumask_empty(mask))
smp_call_function_many(mask, drop_other_mm_ref, mm, 1);
smp_call_function_many(mask, drop_mm_ref_this_cpu, mm, 1);
free_cpumask_var(mask);
}
#else
static void xen_drop_mm_ref(struct mm_struct *mm)
{
if (current->active_mm == mm)
load_cr3(swapper_pg_dir);
drop_mm_ref_this_cpu(mm);
}
#endif
@ -1366,8 +1361,7 @@ static void xen_flush_tlb_single(unsigned long addr)
}
static void xen_flush_tlb_others(const struct cpumask *cpus,
struct mm_struct *mm, unsigned long start,
unsigned long end)
const struct flush_tlb_info *info)
{
struct {
struct mmuext_op op;
@ -1379,7 +1373,7 @@ static void xen_flush_tlb_others(const struct cpumask *cpus,
} *args;
struct multicall_space mcs;
trace_xen_mmu_flush_tlb_others(cpus, mm, start, end);
trace_xen_mmu_flush_tlb_others(cpus, info->mm, info->start, info->end);
if (cpumask_empty(cpus))
return; /* nothing to do */
@ -1393,9 +1387,10 @@ static void xen_flush_tlb_others(const struct cpumask *cpus,
cpumask_clear_cpu(smp_processor_id(), to_cpumask(args->mask));
args->op.cmd = MMUEXT_TLB_FLUSH_MULTI;
if (end != TLB_FLUSH_ALL && (end - start) <= PAGE_SIZE) {
if (info->end != TLB_FLUSH_ALL &&
(info->end - info->start) <= PAGE_SIZE) {
args->op.cmd = MMUEXT_INVLPG_MULTI;
args->op.arg1.linear_addr = start;
args->op.arg1.linear_addr = info->start;
}
MULTI_mmuext_op(mcs.mc, &args->op, 1, NULL, DOMID_SELF);
@ -1470,8 +1465,8 @@ static void xen_write_cr3(unsigned long cr3)
* At the start of the day - when Xen launches a guest, it has already
* built pagetables for the guest. We diligently look over them
* in xen_setup_kernel_pagetable and graft as appropriate them in the
* init_level4_pgt and its friends. Then when we are happy we load
* the new init_level4_pgt - and continue on.
* init_top_pgt and its friends. Then when we are happy we load
* the new init_top_pgt - and continue on.
*
* The generic code starts (start_kernel) and 'init_mem_mapping' sets
* up the rest of the pagetables. When it has completed it loads the cr3.
@ -1914,12 +1909,12 @@ void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
pt_end = pt_base + xen_start_info->nr_pt_frames;
/* Zap identity mapping */
init_level4_pgt[0] = __pgd(0);
init_top_pgt[0] = __pgd(0);
/* Pre-constructed entries are in pfn, so convert to mfn */
/* L4[272] -> level3_ident_pgt */
/* L4[511] -> level3_kernel_pgt */
convert_pfn_mfn(init_level4_pgt);
convert_pfn_mfn(init_top_pgt);
/* L3_i[0] -> level2_ident_pgt */
convert_pfn_mfn(level3_ident_pgt);
@ -1950,10 +1945,10 @@ void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
/* Copy the initial P->M table mappings if necessary. */
i = pgd_index(xen_start_info->mfn_list);
if (i && i < pgd_index(__START_KERNEL_map))
init_level4_pgt[i] = ((pgd_t *)xen_start_info->pt_base)[i];
init_top_pgt[i] = ((pgd_t *)xen_start_info->pt_base)[i];
/* Make pagetable pieces RO */
set_page_prot(init_level4_pgt, PAGE_KERNEL_RO);
set_page_prot(init_top_pgt, PAGE_KERNEL_RO);
set_page_prot(level3_ident_pgt, PAGE_KERNEL_RO);
set_page_prot(level3_kernel_pgt, PAGE_KERNEL_RO);
set_page_prot(level3_user_vsyscall, PAGE_KERNEL_RO);
@ -1964,7 +1959,7 @@ void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
/* Pin down new L4 */
pin_pagetable_pfn(MMUEXT_PIN_L4_TABLE,
PFN_DOWN(__pa_symbol(init_level4_pgt)));
PFN_DOWN(__pa_symbol(init_top_pgt)));
/* Unpin Xen-provided one */
pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
@ -1974,7 +1969,7 @@ void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
* attach it to, so make sure we just set kernel pgd.
*/
xen_mc_batch();
__xen_write_cr3(true, __pa(init_level4_pgt));
__xen_write_cr3(true, __pa(init_top_pgt));
xen_mc_issue(PARAVIRT_LAZY_CPU);
/* We can't that easily rip out L3 and L2, as the Xen pagetables are
@ -2022,7 +2017,7 @@ static phys_addr_t __init xen_early_virt_to_phys(unsigned long vaddr)
pmd_t pmd;
pte_t pte;
pa = read_cr3();
pa = read_cr3_pa();
pgd = native_make_pgd(xen_read_phys_ulong(pa + pgd_index(vaddr) *
sizeof(pgd)));
if (!pgd_present(pgd))
@ -2102,7 +2097,7 @@ void __init xen_relocate_p2m(void)
pt_phys = pmd_phys + PFN_PHYS(n_pmd);
p2m_pfn = PFN_DOWN(pt_phys) + n_pt;
pgd = __va(read_cr3());
pgd = __va(read_cr3_pa());
new_p2m = (unsigned long *)(2 * PGDIR_SIZE);
idx_p4d = 0;
save_pud = n_pud;
@ -2209,7 +2204,7 @@ static void __init xen_write_cr3_init(unsigned long cr3)
{
unsigned long pfn = PFN_DOWN(__pa(swapper_pg_dir));
BUG_ON(read_cr3() != __pa(initial_page_table));
BUG_ON(read_cr3_pa() != __pa(initial_page_table));
BUG_ON(cr3 != __pa(swapper_pg_dir));
/*

2
arch/x86/xen/xen-pvh.S
View File

@ -87,7 +87,7 @@ ENTRY(pvh_start_xen)
wrmsr
/* Enable pre-constructed page tables. */
mov $_pa(init_level4_pgt), %eax
mov $_pa(init_top_pgt), %eax
mov %eax, %cr3
mov $(X86_CR0_PG | X86_CR0_PE), %eax
mov %eax, %cr0

15
include/linux/mm_types_task.h
View File

@ -14,6 +14,10 @@
#include <asm/page.h>
#ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
#include <asm/tlbbatch.h>
#endif
#define USE_SPLIT_PTE_PTLOCKS (NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS)
#define USE_SPLIT_PMD_PTLOCKS (USE_SPLIT_PTE_PTLOCKS && \
IS_ENABLED(CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK))
@ -67,12 +71,15 @@ struct page_frag {
struct tlbflush_unmap_batch {
#ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
/*
* Each bit set is a CPU that potentially has a TLB entry for one of
* the PFNs being flushed. See set_tlb_ubc_flush_pending().
* The arch code makes the following promise: generic code can modify a
* PTE, then call arch_tlbbatch_add_mm() (which internally provides all
* needed barriers), then call arch_tlbbatch_flush(), and the entries
* will be flushed on all CPUs by the time that arch_tlbbatch_flush()
* returns.
*/
struct cpumask cpumask;
struct arch_tlbflush_unmap_batch arch;
/* True if any bit in cpumask is set */
/* True if a flush is needed. */
bool flush_required;
/*

2
include/linux/vm_event_item.h
View File

@ -93,10 +93,8 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
#endif
#endif
#ifdef CONFIG_DEBUG_TLBFLUSH
#ifdef CONFIG_SMP
NR_TLB_REMOTE_FLUSH, /* cpu tried to flush others' tlbs */
NR_TLB_REMOTE_FLUSH_RECEIVED,/* cpu received ipi for flush */
#endif /* CONFIG_SMP */
NR_TLB_LOCAL_FLUSH_ALL,
NR_TLB_LOCAL_FLUSH_ONE,
#endif /* CONFIG_DEBUG_TLBFLUSH */

2
mm/Kconfig
View File

@ -137,7 +137,7 @@ config HAVE_MEMBLOCK_NODE_MAP
config HAVE_MEMBLOCK_PHYS_MAP
bool
config HAVE_GENERIC_RCU_GUP
config HAVE_GENERIC_GUP
bool
config ARCH_DISCARD_MEMBLOCK

10
mm/gup.c
View File

@ -1146,7 +1146,7 @@ struct page *get_dump_page(unsigned long addr)
#endif /* CONFIG_ELF_CORE */
/*
* Generic RCU Fast GUP
* Generic Fast GUP
*
* get_user_pages_fast attempts to pin user pages by walking the page
* tables directly and avoids taking locks. Thus the walker needs to be
@ -1167,8 +1167,8 @@ struct page *get_dump_page(unsigned long addr)
* Before activating this code, please be aware that the following assumptions
* are currently made:
*
* *) HAVE_RCU_TABLE_FREE is enabled, and tlb_remove_table is used to free
* pages containing page tables.
* *) Either HAVE_RCU_TABLE_FREE is enabled, and tlb_remove_table() is used to
* free pages containing page tables or TLB flushing requires IPI broadcast.
*
* *) ptes can be read atomically by the architecture.
*
@ -1178,7 +1178,7 @@ struct page *get_dump_page(unsigned long addr)
*
* This code is based heavily on the PowerPC implementation by Nick Piggin.
*/
#ifdef CONFIG_HAVE_GENERIC_RCU_GUP
#ifdef CONFIG_HAVE_GENERIC_GUP
#ifndef gup_get_pte
/*
@ -1668,4 +1668,4 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write,
return ret;
}
#endif /* CONFIG_HAVE_GENERIC_RCU_GUP */
#endif /* CONFIG_HAVE_GENERIC_GUP */

16
mm/rmap.c
View File

@ -579,25 +579,13 @@ void page_unlock_anon_vma_read(struct anon_vma *anon_vma)
void try_to_unmap_flush(void)
{
struct tlbflush_unmap_batch *tlb_ubc = &current->tlb_ubc;
int cpu;
if (!tlb_ubc->flush_required)
return;
cpu = get_cpu();
if (cpumask_test_cpu(cpu, &tlb_ubc->cpumask)) {
count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
local_flush_tlb();
trace_tlb_flush(TLB_LOCAL_SHOOTDOWN, TLB_FLUSH_ALL);
}
if (cpumask_any_but(&tlb_ubc->cpumask, cpu) < nr_cpu_ids)
flush_tlb_others(&tlb_ubc->cpumask, NULL, 0, TLB_FLUSH_ALL);
cpumask_clear(&tlb_ubc->cpumask);
arch_tlbbatch_flush(&tlb_ubc->arch);
tlb_ubc->flush_required = false;
tlb_ubc->writable = false;
put_cpu();
}
/* Flush iff there are potentially writable TLB entries that can race with IO */
@ -613,7 +601,7 @@ static void set_tlb_ubc_flush_pending(struct mm_struct *mm, bool writable)
{
struct tlbflush_unmap_batch *tlb_ubc = &current->tlb_ubc;
cpumask_or(&tlb_ubc->cpumask, &tlb_ubc->cpumask, mm_cpumask(mm));
arch_tlbbatch_add_mm(&tlb_ubc->arch, mm);
tlb_ubc->flush_required = true;
/*