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211 lines
4.5 KiB
211 lines
4.5 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* linux/arch/arm/mm/pgd.c |
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* |
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* Copyright (C) 1998-2005 Russell King |
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*/ |
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#include <linux/mm.h> |
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#include <linux/gfp.h> |
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#include <linux/highmem.h> |
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#include <linux/slab.h> |
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#include <asm/cp15.h> |
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#include <asm/pgalloc.h> |
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#include <asm/page.h> |
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#include <asm/tlbflush.h> |
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#include "mm.h" |
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#ifdef CONFIG_ARM_LPAE |
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#define __pgd_alloc() kmalloc_array(PTRS_PER_PGD, sizeof(pgd_t), GFP_KERNEL) |
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#define __pgd_free(pgd) kfree(pgd) |
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#else |
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#define __pgd_alloc() (pgd_t *)__get_free_pages(GFP_KERNEL, 2) |
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#define __pgd_free(pgd) free_pages((unsigned long)pgd, 2) |
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#endif |
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/* |
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* need to get a 16k page for level 1 |
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*/ |
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pgd_t *pgd_alloc(struct mm_struct *mm) |
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{ |
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pgd_t *new_pgd, *init_pgd; |
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p4d_t *new_p4d, *init_p4d; |
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pud_t *new_pud, *init_pud; |
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pmd_t *new_pmd, *init_pmd; |
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pte_t *new_pte, *init_pte; |
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new_pgd = __pgd_alloc(); |
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if (!new_pgd) |
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goto no_pgd; |
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memset(new_pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t)); |
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/* |
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* Copy over the kernel and IO PGD entries |
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*/ |
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init_pgd = pgd_offset_k(0); |
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memcpy(new_pgd + USER_PTRS_PER_PGD, init_pgd + USER_PTRS_PER_PGD, |
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(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t)); |
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clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t)); |
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#ifdef CONFIG_ARM_LPAE |
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/* |
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* Allocate PMD table for modules and pkmap mappings. |
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*/ |
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new_p4d = p4d_alloc(mm, new_pgd + pgd_index(MODULES_VADDR), |
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MODULES_VADDR); |
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if (!new_p4d) |
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goto no_p4d; |
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new_pud = pud_alloc(mm, new_p4d, MODULES_VADDR); |
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if (!new_pud) |
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goto no_pud; |
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new_pmd = pmd_alloc(mm, new_pud, 0); |
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if (!new_pmd) |
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goto no_pmd; |
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#ifdef CONFIG_KASAN |
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/* |
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* Copy PMD table for KASAN shadow mappings. |
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*/ |
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init_pgd = pgd_offset_k(TASK_SIZE); |
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init_p4d = p4d_offset(init_pgd, TASK_SIZE); |
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init_pud = pud_offset(init_p4d, TASK_SIZE); |
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init_pmd = pmd_offset(init_pud, TASK_SIZE); |
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new_pmd = pmd_offset(new_pud, TASK_SIZE); |
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memcpy(new_pmd, init_pmd, |
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(pmd_index(MODULES_VADDR) - pmd_index(TASK_SIZE)) |
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* sizeof(pmd_t)); |
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clean_dcache_area(new_pmd, PTRS_PER_PMD * sizeof(pmd_t)); |
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#endif /* CONFIG_KASAN */ |
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#endif /* CONFIG_LPAE */ |
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if (!vectors_high()) { |
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/* |
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* On ARM, first page must always be allocated since it |
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* contains the machine vectors. The vectors are always high |
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* with LPAE. |
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*/ |
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new_p4d = p4d_alloc(mm, new_pgd, 0); |
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if (!new_p4d) |
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goto no_p4d; |
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new_pud = pud_alloc(mm, new_p4d, 0); |
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if (!new_pud) |
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goto no_pud; |
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new_pmd = pmd_alloc(mm, new_pud, 0); |
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if (!new_pmd) |
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goto no_pmd; |
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new_pte = pte_alloc_map(mm, new_pmd, 0); |
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if (!new_pte) |
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goto no_pte; |
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#ifndef CONFIG_ARM_LPAE |
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/* |
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* Modify the PTE pointer to have the correct domain. This |
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* needs to be the vectors domain to avoid the low vectors |
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* being unmapped. |
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*/ |
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pmd_val(*new_pmd) &= ~PMD_DOMAIN_MASK; |
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pmd_val(*new_pmd) |= PMD_DOMAIN(DOMAIN_VECTORS); |
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#endif |
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init_p4d = p4d_offset(init_pgd, 0); |
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init_pud = pud_offset(init_p4d, 0); |
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init_pmd = pmd_offset(init_pud, 0); |
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init_pte = pte_offset_map(init_pmd, 0); |
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set_pte_ext(new_pte + 0, init_pte[0], 0); |
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set_pte_ext(new_pte + 1, init_pte[1], 0); |
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pte_unmap(init_pte); |
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pte_unmap(new_pte); |
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} |
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return new_pgd; |
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no_pte: |
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pmd_free(mm, new_pmd); |
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mm_dec_nr_pmds(mm); |
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no_pmd: |
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pud_free(mm, new_pud); |
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no_pud: |
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p4d_free(mm, new_p4d); |
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no_p4d: |
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__pgd_free(new_pgd); |
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no_pgd: |
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return NULL; |
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} |
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void pgd_free(struct mm_struct *mm, 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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pgtable_t pte; |
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if (!pgd_base) |
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return; |
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pgd = pgd_base + pgd_index(0); |
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if (pgd_none_or_clear_bad(pgd)) |
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goto no_pgd; |
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p4d = p4d_offset(pgd, 0); |
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if (p4d_none_or_clear_bad(p4d)) |
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goto no_p4d; |
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pud = pud_offset(p4d, 0); |
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if (pud_none_or_clear_bad(pud)) |
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goto no_pud; |
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pmd = pmd_offset(pud, 0); |
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if (pmd_none_or_clear_bad(pmd)) |
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goto no_pmd; |
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pte = pmd_pgtable(*pmd); |
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pmd_clear(pmd); |
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pte_free(mm, pte); |
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mm_dec_nr_ptes(mm); |
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no_pmd: |
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pud_clear(pud); |
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pmd_free(mm, pmd); |
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mm_dec_nr_pmds(mm); |
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no_pud: |
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p4d_clear(p4d); |
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pud_free(mm, pud); |
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no_p4d: |
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pgd_clear(pgd); |
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p4d_free(mm, p4d); |
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no_pgd: |
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#ifdef CONFIG_ARM_LPAE |
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/* |
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* Free modules/pkmap or identity pmd tables. |
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*/ |
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for (pgd = pgd_base; pgd < pgd_base + PTRS_PER_PGD; pgd++) { |
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if (pgd_none_or_clear_bad(pgd)) |
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continue; |
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if (pgd_val(*pgd) & L_PGD_SWAPPER) |
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continue; |
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p4d = p4d_offset(pgd, 0); |
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if (p4d_none_or_clear_bad(p4d)) |
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continue; |
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pud = pud_offset(p4d, 0); |
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if (pud_none_or_clear_bad(pud)) |
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continue; |
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pmd = pmd_offset(pud, 0); |
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pud_clear(pud); |
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pmd_free(mm, pmd); |
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mm_dec_nr_pmds(mm); |
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p4d_clear(p4d); |
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pud_free(mm, pud); |
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mm_dec_nr_puds(mm); |
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pgd_clear(pgd); |
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p4d_free(mm, p4d); |
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} |
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#endif |
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__pgd_free(pgd_base); |
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}
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