| Message ID | 20230801220733.1987762-4-surenb@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | make vma locking more obvious | expand |
* Suren Baghdasaryan <surenb@google.com> [230801 18:07]: > Vma write lock assertion always includes mmap write lock assertion and > additional vma lock checks when per-VMA locks are enabled. Replace > weaker mmap_assert_write_locked() assertions with stronger > vma_assert_write_locked() ones when we are operating on a vma which > is expected to be locked. > > Suggested-by: Jann Horn <jannh@google.com> > Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> > --- > mm/hugetlb.c | 2 +- > mm/khugepaged.c | 5 +++-- > mm/memory.c | 2 +- > 3 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 64a3239b6407..1d871a1167d8 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -5028,7 +5028,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, > src_vma->vm_start, > src_vma->vm_end); > mmu_notifier_invalidate_range_start(&range); > - mmap_assert_write_locked(src); > + vma_assert_write_locked(src_vma); > raw_write_seqcount_begin(&src->write_protect_seq); > } else { > /* > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index 78c8d5d8b628..1e43a56fba31 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -1495,7 +1495,7 @@ static int set_huge_pmd(struct vm_area_struct *vma, unsigned long addr, > }; > > VM_BUG_ON(!PageTransHuge(hpage)); > - mmap_assert_write_locked(vma->vm_mm); > + vma_assert_write_locked(vma); > > if (do_set_pmd(&vmf, hpage)) > return SCAN_FAIL; > @@ -1525,7 +1525,7 @@ static void collapse_and_free_pmd(struct mm_struct *mm, struct vm_area_struct *v > pmd_t pmd; > struct mmu_notifier_range range; > > - mmap_assert_write_locked(mm); > + vma_assert_write_locked(vma); > if (vma->vm_file) > lockdep_assert_held_write(&vma->vm_file->f_mapping->i_mmap_rwsem); > /* > @@ -1570,6 +1570,7 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, > int count = 0, result = SCAN_FAIL; > int i; > > + /* Ensure vma can't change, it will be locked below after checks */ > mmap_assert_write_locked(mm); > > /* Fast check before locking page if already PMD-mapped */ > diff --git a/mm/memory.c b/mm/memory.c > index 603b2f419948..652d99b9858a 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -1312,7 +1312,7 @@ copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma) > * Use the raw variant of the seqcount_t write API to avoid > * lockdep complaining about preemptibility. > */ > - mmap_assert_write_locked(src_mm); > + vma_assert_write_locked(src_vma); > raw_write_seqcount_begin(&src_mm->write_protect_seq); > } > > -- > 2.41.0.585.gd2178a4bd4-goog >
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 64a3239b6407..1d871a1167d8 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5028,7 +5028,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, src_vma->vm_start, src_vma->vm_end); mmu_notifier_invalidate_range_start(&range); - mmap_assert_write_locked(src); + vma_assert_write_locked(src_vma); raw_write_seqcount_begin(&src->write_protect_seq); } else { /* diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 78c8d5d8b628..1e43a56fba31 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1495,7 +1495,7 @@ static int set_huge_pmd(struct vm_area_struct *vma, unsigned long addr, }; VM_BUG_ON(!PageTransHuge(hpage)); - mmap_assert_write_locked(vma->vm_mm); + vma_assert_write_locked(vma); if (do_set_pmd(&vmf, hpage)) return SCAN_FAIL; @@ -1525,7 +1525,7 @@ static void collapse_and_free_pmd(struct mm_struct *mm, struct vm_area_struct *v pmd_t pmd; struct mmu_notifier_range range; - mmap_assert_write_locked(mm); + vma_assert_write_locked(vma); if (vma->vm_file) lockdep_assert_held_write(&vma->vm_file->f_mapping->i_mmap_rwsem); /* @@ -1570,6 +1570,7 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, int count = 0, result = SCAN_FAIL; int i; + /* Ensure vma can't change, it will be locked below after checks */ mmap_assert_write_locked(mm); /* Fast check before locking page if already PMD-mapped */ diff --git a/mm/memory.c b/mm/memory.c index 603b2f419948..652d99b9858a 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1312,7 +1312,7 @@ copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma) * Use the raw variant of the seqcount_t write API to avoid * lockdep complaining about preemptibility. */ - mmap_assert_write_locked(src_mm); + vma_assert_write_locked(src_vma); raw_write_seqcount_begin(&src_mm->write_protect_seq); }
Vma write lock assertion always includes mmap write lock assertion and additional vma lock checks when per-VMA locks are enabled. Replace weaker mmap_assert_write_locked() assertions with stronger vma_assert_write_locked() ones when we are operating on a vma which is expected to be locked. Suggested-by: Jann Horn <jannh@google.com> Signed-off-by: Suren Baghdasaryan <surenb@google.com> --- mm/hugetlb.c | 2 +- mm/khugepaged.c | 5 +++-- mm/memory.c | 2 +- 3 files changed, 5 insertions(+), 4 deletions(-)