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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>
70 lines
1.5 KiB
C
70 lines
1.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* arch/arm/include/asm/tlb.h
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*
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* Copyright (C) 2002 Russell King
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*
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* Experimentation shows that on a StrongARM, it appears to be faster
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* to use the "invalidate whole tlb" rather than "invalidate single
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* tlb" for this.
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*
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* This appears true for both the process fork+exit case, as well as
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* the munmap-large-area case.
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*/
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#ifndef __ASMARM_TLB_H
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#define __ASMARM_TLB_H
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#include <asm/cacheflush.h>
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#ifndef CONFIG_MMU
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#include <linux/pagemap.h>
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#define tlb_flush(tlb) ((void) tlb)
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#include <asm-generic/tlb.h>
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#else /* !CONFIG_MMU */
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#include <linux/swap.h>
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#include <asm/tlbflush.h>
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static inline void __tlb_remove_table(void *_table)
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{
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free_page_and_swap_cache((struct page *)_table);
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}
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#include <asm-generic/tlb.h>
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static inline void
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__pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, unsigned long addr)
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{
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struct ptdesc *ptdesc = page_ptdesc(pte);
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pagetable_dtor(ptdesc);
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#ifndef CONFIG_ARM_LPAE
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/*
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* With the classic ARM MMU, a pte page has two corresponding pmd
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* entries, each covering 1MB.
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*/
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addr = (addr & PMD_MASK) + SZ_1M;
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__tlb_adjust_range(tlb, addr - PAGE_SIZE, 2 * PAGE_SIZE);
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#endif
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tlb_remove_ptdesc(tlb, ptdesc);
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}
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static inline void
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__pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp, unsigned long addr)
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{
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#ifdef CONFIG_ARM_LPAE
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struct ptdesc *ptdesc = virt_to_ptdesc(pmdp);
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pagetable_dtor(ptdesc);
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tlb_remove_ptdesc(tlb, ptdesc);
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#endif
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}
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#endif /* CONFIG_MMU */
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#endif
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