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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>
55 lines
1.2 KiB
C
55 lines
1.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
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* Copyright 2003 PathScale, Inc.
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* Derived from include/asm-i386/pgalloc.h and include/asm-i386/pgtable.h
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*/
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#ifndef __UM_PGALLOC_H
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#define __UM_PGALLOC_H
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#include <linux/mm.h>
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#include <asm-generic/pgalloc.h>
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#define pmd_populate_kernel(mm, pmd, pte) \
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set_pmd(pmd, __pmd(_PAGE_TABLE + (unsigned long) __pa(pte)))
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#define pmd_populate(mm, pmd, pte) \
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set_pmd(pmd, __pmd(_PAGE_TABLE + \
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((unsigned long long)page_to_pfn(pte) << \
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(unsigned long long) PAGE_SHIFT)))
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/*
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* Allocate and free page tables.
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*/
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extern pgd_t *pgd_alloc(struct mm_struct *);
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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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#if CONFIG_PGTABLE_LEVELS > 2
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#define __pmd_free_tlb(tlb, pmd, address) \
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do { \
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pagetable_dtor(virt_to_ptdesc(pmd)); \
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tlb_remove_page_ptdesc((tlb), virt_to_ptdesc(pmd)); \
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} while (0)
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#if CONFIG_PGTABLE_LEVELS > 3
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#define __pud_free_tlb(tlb, pud, address) \
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do { \
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pagetable_dtor(virt_to_ptdesc(pud)); \
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tlb_remove_page_ptdesc((tlb), virt_to_ptdesc(pud)); \
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} while (0)
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#endif
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#endif
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#endif
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