59511cfd08
As the kernel and user space page tables are strictly mutually exclusive when it comes to executable permissions, we can set the UXN table attribute on all table entries that are created while creating kernel mappings in the swapper page tables, and the PXN table attribute on all table entries that are created while creating user space mappings in user space page tables. While at it, get rid of a redundant comment. Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20210310104942.174584-4-ardb@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
92 lines
2.2 KiB
C
92 lines
2.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Based on arch/arm/include/asm/pgalloc.h
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*
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* Copyright (C) 2000-2001 Russell King
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* Copyright (C) 2012 ARM Ltd.
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*/
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#ifndef __ASM_PGALLOC_H
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#define __ASM_PGALLOC_H
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#include <asm/pgtable-hwdef.h>
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#include <asm/processor.h>
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#include <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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#define __HAVE_ARCH_PGD_FREE
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#include <asm-generic/pgalloc.h>
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#define PGD_SIZE (PTRS_PER_PGD * sizeof(pgd_t))
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#if CONFIG_PGTABLE_LEVELS > 2
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static inline void __pud_populate(pud_t *pudp, phys_addr_t pmdp, pudval_t prot)
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{
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set_pud(pudp, __pud(__phys_to_pud_val(pmdp) | prot));
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}
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static inline void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmdp)
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{
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pudval_t pudval = PUD_TYPE_TABLE;
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pudval |= (mm == &init_mm) ? PUD_TABLE_UXN : PUD_TABLE_PXN;
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__pud_populate(pudp, __pa(pmdp), pudval);
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}
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#else
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static inline void __pud_populate(pud_t *pudp, phys_addr_t pmdp, pudval_t prot)
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{
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BUILD_BUG();
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}
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#endif /* CONFIG_PGTABLE_LEVELS > 2 */
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#if CONFIG_PGTABLE_LEVELS > 3
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static inline void __p4d_populate(p4d_t *p4dp, phys_addr_t pudp, p4dval_t prot)
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{
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set_p4d(p4dp, __p4d(__phys_to_p4d_val(pudp) | prot));
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}
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static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4dp, pud_t *pudp)
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{
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p4dval_t p4dval = P4D_TYPE_TABLE;
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p4dval |= (mm == &init_mm) ? P4D_TABLE_UXN : P4D_TABLE_PXN;
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__p4d_populate(p4dp, __pa(pudp), p4dval);
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}
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#else
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static inline void __p4d_populate(p4d_t *p4dp, phys_addr_t pudp, p4dval_t prot)
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{
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BUILD_BUG();
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}
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#endif /* CONFIG_PGTABLE_LEVELS > 3 */
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extern pgd_t *pgd_alloc(struct mm_struct *mm);
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extern void pgd_free(struct mm_struct *mm, pgd_t *pgdp);
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static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t ptep,
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pmdval_t prot)
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{
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set_pmd(pmdp, __pmd(__phys_to_pmd_val(ptep) | prot));
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}
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/*
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* Populate the pmdp entry with a pointer to the pte. This pmd is part
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* of the mm address space.
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*/
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static inline void
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pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
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{
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VM_BUG_ON(mm != &init_mm);
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__pmd_populate(pmdp, __pa(ptep), PMD_TYPE_TABLE | PMD_TABLE_UXN);
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}
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static inline void
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pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
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{
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VM_BUG_ON(mm == &init_mm);
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__pmd_populate(pmdp, page_to_phys(ptep), PMD_TYPE_TABLE | PMD_TABLE_PXN);
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}
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#define pmd_pgtable(pmd) pmd_page(pmd)
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#endif
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