mirror of https://gitee.com/openkylin/linux.git
232 lines
5.4 KiB
C
232 lines
5.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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*/
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#include <linux/stddef.h>
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#include <linux/module.h>
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#include <linux/memblock.h>
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#include <linux/highmem.h>
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#include <linux/mm.h>
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#include <linux/swap.h>
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#include <linux/slab.h>
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#include <asm/fixmap.h>
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#include <asm/page.h>
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#include <as-layout.h>
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#include <init.h>
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#include <kern.h>
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#include <kern_util.h>
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#include <mem_user.h>
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#include <os.h>
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/* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
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unsigned long *empty_zero_page = NULL;
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EXPORT_SYMBOL(empty_zero_page);
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/*
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* Initialized during boot, and readonly for initializing page tables
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* afterwards
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*/
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pgd_t swapper_pg_dir[PTRS_PER_PGD];
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/* Initialized at boot time, and readonly after that */
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unsigned long long highmem;
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EXPORT_SYMBOL(highmem);
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int kmalloc_ok = 0;
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/* Used during early boot */
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static unsigned long brk_end;
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void __init mem_init(void)
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{
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/* clear the zero-page */
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memset(empty_zero_page, 0, PAGE_SIZE);
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/* Map in the area just after the brk now that kmalloc is about
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* to be turned on.
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*/
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brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
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map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
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memblock_free(__pa(brk_end), uml_reserved - brk_end);
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uml_reserved = brk_end;
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/* this will put all low memory onto the freelists */
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memblock_free_all();
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max_low_pfn = totalram_pages();
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max_pfn = max_low_pfn;
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mem_init_print_info(NULL);
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kmalloc_ok = 1;
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}
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/*
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* Create a page table and place a pointer to it in a middle page
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* directory entry.
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*/
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static void __init one_page_table_init(pmd_t *pmd)
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{
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if (pmd_none(*pmd)) {
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pte_t *pte = (pte_t *) memblock_alloc_low(PAGE_SIZE,
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PAGE_SIZE);
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if (!pte)
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panic("%s: Failed to allocate %lu bytes align=%lx\n",
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__func__, PAGE_SIZE, PAGE_SIZE);
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set_pmd(pmd, __pmd(_KERNPG_TABLE +
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(unsigned long) __pa(pte)));
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if (pte != pte_offset_kernel(pmd, 0))
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BUG();
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}
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}
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static void __init one_md_table_init(pud_t *pud)
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{
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#ifdef CONFIG_3_LEVEL_PGTABLES
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pmd_t *pmd_table = (pmd_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
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if (!pmd_table)
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panic("%s: Failed to allocate %lu bytes align=%lx\n",
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__func__, PAGE_SIZE, PAGE_SIZE);
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set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
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if (pmd_table != pmd_offset(pud, 0))
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BUG();
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#endif
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}
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static void __init fixrange_init(unsigned long start, unsigned long end,
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pgd_t *pgd_base)
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{
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pgd_t *pgd;
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p4d_t *p4d;
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pud_t *pud;
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pmd_t *pmd;
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int i, j;
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unsigned long vaddr;
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vaddr = start;
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i = pgd_index(vaddr);
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j = pmd_index(vaddr);
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pgd = pgd_base + i;
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for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
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p4d = p4d_offset(pgd, vaddr);
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pud = pud_offset(p4d, vaddr);
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if (pud_none(*pud))
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one_md_table_init(pud);
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pmd = pmd_offset(pud, vaddr);
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for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) {
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one_page_table_init(pmd);
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vaddr += PMD_SIZE;
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}
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j = 0;
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}
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}
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static void __init fixaddr_user_init( void)
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{
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#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
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long size = FIXADDR_USER_END - FIXADDR_USER_START;
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pgd_t *pgd;
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p4d_t *p4d;
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pud_t *pud;
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pmd_t *pmd;
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pte_t *pte;
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phys_t p;
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unsigned long v, vaddr = FIXADDR_USER_START;
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if (!size)
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return;
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fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
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v = (unsigned long) memblock_alloc_low(size, PAGE_SIZE);
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if (!v)
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panic("%s: Failed to allocate %lu bytes align=%lx\n",
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__func__, size, PAGE_SIZE);
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memcpy((void *) v , (void *) FIXADDR_USER_START, size);
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p = __pa(v);
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for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
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p += PAGE_SIZE) {
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pgd = swapper_pg_dir + pgd_index(vaddr);
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p4d = p4d_offset(pgd, vaddr);
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pud = pud_offset(p4d, vaddr);
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pmd = pmd_offset(pud, vaddr);
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pte = pte_offset_kernel(pmd, vaddr);
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pte_set_val(*pte, p, PAGE_READONLY);
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}
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#endif
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}
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void __init paging_init(void)
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{
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unsigned long zones_size[MAX_NR_ZONES], vaddr;
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int i;
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empty_zero_page = (unsigned long *) memblock_alloc_low(PAGE_SIZE,
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PAGE_SIZE);
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if (!empty_zero_page)
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panic("%s: Failed to allocate %lu bytes align=%lx\n",
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__func__, PAGE_SIZE, PAGE_SIZE);
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for (i = 0; i < ARRAY_SIZE(zones_size); i++)
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zones_size[i] = 0;
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zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) -
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(uml_physmem >> PAGE_SHIFT);
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free_area_init(zones_size);
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/*
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* Fixed mappings, only the page table structure has to be
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* created - mappings will be set by set_fixmap():
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*/
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vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
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fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);
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fixaddr_user_init();
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}
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/*
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* This can't do anything because nothing in the kernel image can be freed
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* since it's not in kernel physical memory.
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*/
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void free_initmem(void)
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{
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}
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/* Allocate and free page tables. */
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pgd_t *pgd_alloc(struct mm_struct *mm)
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{
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pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
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if (pgd) {
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memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
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memcpy(pgd + USER_PTRS_PER_PGD,
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swapper_pg_dir + USER_PTRS_PER_PGD,
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(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
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}
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return pgd;
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}
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void pgd_free(struct mm_struct *mm, pgd_t *pgd)
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{
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free_page((unsigned long) pgd);
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}
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#ifdef CONFIG_3_LEVEL_PGTABLES
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pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
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{
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pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL);
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if (pmd)
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memset(pmd, 0, PAGE_SIZE);
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return pmd;
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}
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#endif
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void *uml_kmalloc(int size, int flags)
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{
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return kmalloc(size, flags);
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}
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