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db6b435d73
The pagetable_p*_dtor() are exactly the same except for the handling of ptlock. If we make ptlock_free() handle the case where ptdesc->ptl is NULL and remove VM_BUG_ON_PAGE() from pmd_ptlock_free(), we can unify pagetable_p*_dtor() into one function. Let's introduce pagetable_dtor() to do this. Later, pagetable_dtor() will be moved to tlb_remove_ptdesc(), so that ptlock and page table pages can be freed together (regardless of whether RCU is used). This prevents the use-after-free problem where the ptlock is freed immediately but the page table pages is freed later via RCU. Link: https://lkml.kernel.org/r/47f44fff9dc68d9d9e9a0d6c036df275f820598a.1736317725.git.zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Originally-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> [s390] Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
111 lines
2.3 KiB
C
111 lines
2.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
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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 <linux/mm.h>
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#include <linux/sched.h>
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#define __HAVE_ARCH_PMD_ALLOC_ONE
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#define __HAVE_ARCH_PUD_ALLOC_ONE
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#define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
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#include <asm-generic/pgalloc.h>
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static inline void pmd_populate_kernel(struct mm_struct *mm,
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pmd_t *pmd, pte_t *pte)
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{
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set_pmd(pmd, __pmd((unsigned long)pte));
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}
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static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, pgtable_t pte)
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{
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set_pmd(pmd, __pmd((unsigned long)page_address(pte)));
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}
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#ifndef __PAGETABLE_PMD_FOLDED
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static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
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{
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set_pud(pud, __pud((unsigned long)pmd));
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}
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#endif
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#ifndef __PAGETABLE_PUD_FOLDED
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static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
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{
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set_p4d(p4d, __p4d((unsigned long)pud));
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}
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#endif /* __PAGETABLE_PUD_FOLDED */
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extern void pagetable_init(void);
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extern pgd_t *pgd_alloc(struct mm_struct *mm);
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static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
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{
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pte_t *pte = __pte_alloc_one_kernel(mm);
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if (pte)
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kernel_pte_init(pte);
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return pte;
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}
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#define __pte_free_tlb(tlb, pte, address) \
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do { \
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pagetable_dtor(page_ptdesc(pte)); \
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tlb_remove_page_ptdesc((tlb), page_ptdesc(pte)); \
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} while (0)
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#ifndef __PAGETABLE_PMD_FOLDED
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static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
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{
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pmd_t *pmd;
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struct ptdesc *ptdesc;
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ptdesc = pagetable_alloc(GFP_KERNEL_ACCOUNT, 0);
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if (!ptdesc)
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return NULL;
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if (!pagetable_pmd_ctor(ptdesc)) {
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pagetable_free(ptdesc);
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return NULL;
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}
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pmd = ptdesc_address(ptdesc);
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pmd_init(pmd);
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return pmd;
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}
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#define __pmd_free_tlb(tlb, x, addr) pmd_free((tlb)->mm, x)
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#endif
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#ifndef __PAGETABLE_PUD_FOLDED
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static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
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{
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pud_t *pud;
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struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0);
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if (!ptdesc)
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return NULL;
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pagetable_pud_ctor(ptdesc);
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pud = ptdesc_address(ptdesc);
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pud_init(pud);
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return pud;
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}
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#define __pud_free_tlb(tlb, x, addr) pud_free((tlb)->mm, x)
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#endif /* __PAGETABLE_PUD_FOLDED */
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extern pte_t * __init populate_kernel_pte(unsigned long addr);
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#endif /* _ASM_PGALLOC_H */
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