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d3eb70ead6
trans_pgd_create_copy() can hit "VM_BUG_ON(mm != &init_mm)" in the function pmd_populate_kernel(). This is the combined consequence of commit5de59884ac("arm64: trans_pgd: pass NULL instead of init_mm to *_populate functions"), which replaced &init_mm with NULL and commit59511cfd08("arm64: mm: use XN table mapping attributes for user/kernel mappings"), which introduced the VM_BUG_ON. Since the former sounds reasonable, it is better to work on the later. From the perspective of trans_pgd, two groups of functions are considered in the later one: pmd_populate_kernel() mm == NULL should be fixed, else it hits VM_BUG_ON() p?d_populate() mm == NULL means PXN, that is OK, since trans_pgd only copies a linear map, no execution will happen on the map. So it is good enough to just relax VM_BUG_ON() to disregard mm == NULL Fixes:59511cfd08("arm64: mm: use XN table mapping attributes for user/kernel mappings") Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Cc: <stable@vger.kernel.org> # 5.13.x Cc: Ard Biesheuvel <ardb@kernel.org> Cc: James Morse <james.morse@arm.com> Cc: Matthias Brugger <mbrugger@suse.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Link: https://lore.kernel.org/r/20211112052214.9086-1-kernelfans@gmail.com Signed-off-by: Will Deacon <will@kernel.org>
91 lines
2.2 KiB
C
91 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 && 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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#endif
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