diff options
| author | Suren Baghdasaryan <surenb@google.com> | 2023-02-27 09:36:18 -0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-04-05 20:02:59 -0700 |
| commit | 98e51a2239d9d419d819cd61a2e720ebf19a8b0a (patch) | |
| tree | 5db03b809222a234cbf9ff9d0cf69ec277c9697c | |
| parent | 73046fd00b069ffd198eda099dae966e152fae39 (diff) | |
mm: conditionally write-lock VMA in free_pgtables
Normally free_pgtables needs to lock affected VMAs except for the case
when VMAs were isolated under VMA write-lock. munmap() does just that,
isolating while holding appropriate locks and then downgrading mmap_lock
and dropping per-VMA locks before freeing page tables. Add a parameter to
free_pgtables for such scenario.
Link: https://lkml.kernel.org/r/20230227173632.3292573-20-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | mm/internal.h | 2 | ||||
| -rw-r--r-- | mm/memory.c | 6 | ||||
| -rw-r--r-- | mm/mmap.c | 5 |
3 files changed, 9 insertions, 4 deletions
diff --git a/mm/internal.h b/mm/internal.h index 82ba61d0ed6a2..73b167b59cc53 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -105,7 +105,7 @@ void folio_activate(struct folio *folio); void free_pgtables(struct mmu_gather *tlb, struct maple_tree *mt, struct vm_area_struct *start_vma, unsigned long floor, - unsigned long ceiling); + unsigned long ceiling, bool mm_wr_locked); void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte); struct zap_details; diff --git a/mm/memory.c b/mm/memory.c index ec7e89cc05323..8ca78ae8bba77 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -362,7 +362,7 @@ void free_pgd_range(struct mmu_gather *tlb, void free_pgtables(struct mmu_gather *tlb, struct maple_tree *mt, struct vm_area_struct *vma, unsigned long floor, - unsigned long ceiling) + unsigned long ceiling, bool mm_wr_locked) { MA_STATE(mas, mt, vma->vm_end, vma->vm_end); @@ -380,6 +380,8 @@ void free_pgtables(struct mmu_gather *tlb, struct maple_tree *mt, * Hide vma from rmap and truncate_pagecache before freeing * pgtables */ + if (mm_wr_locked) + vma_start_write(vma); unlink_anon_vmas(vma); unlink_file_vma(vma); @@ -394,6 +396,8 @@ void free_pgtables(struct mmu_gather *tlb, struct maple_tree *mt, && !is_vm_hugetlb_page(next)) { vma = next; next = mas_find(&mas, ceiling - 1); + if (mm_wr_locked) + vma_start_write(vma); unlink_anon_vmas(vma); unlink_file_vma(vma); } diff --git a/mm/mmap.c b/mm/mmap.c index 83adf86fd62b1..58704ca5acd2c 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2167,7 +2167,8 @@ static void unmap_region(struct mm_struct *mm, struct maple_tree *mt, update_hiwater_rss(mm); unmap_vmas(&tlb, mt, vma, start, end, mm_wr_locked); free_pgtables(&tlb, mt, vma, prev ? prev->vm_end : FIRST_USER_ADDRESS, - next ? next->vm_start : USER_PGTABLES_CEILING); + next ? next->vm_start : USER_PGTABLES_CEILING, + mm_wr_locked); tlb_finish_mmu(&tlb); } @@ -3064,7 +3065,7 @@ void exit_mmap(struct mm_struct *mm) set_bit(MMF_OOM_SKIP, &mm->flags); mmap_write_lock(mm); free_pgtables(&tlb, &mm->mm_mt, vma, FIRST_USER_ADDRESS, - USER_PGTABLES_CEILING); + USER_PGTABLES_CEILING, true); tlb_finish_mmu(&tlb); /* |