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    Subject[PATCH v2 29/61] arch/x86: Use maple tree iterators for vdso/vma
    Date
    From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>

    Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
    ---
    arch/x86/entry/vdso/vma.c | 12 ++++++++++--
    1 file changed, 10 insertions(+), 2 deletions(-)

    diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
    index 235a5794296a..c0b160a9585d 100644
    --- a/arch/x86/entry/vdso/vma.c
    +++ b/arch/x86/entry/vdso/vma.c
    @@ -128,15 +128,19 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
    struct mm_struct *mm = task->mm;
    struct vm_area_struct *vma;

    + MA_STATE(mas, &mm->mm_mt, 0, 0);
    +
    mmap_read_lock(mm);
    + rcu_read_lock();

    - for (vma = mm->mmap; vma; vma = vma->vm_next) {
    + mas_for_each(&mas, vma, ULONG_MAX) {
    unsigned long size = vma->vm_end - vma->vm_start;

    if (vma_is_special_mapping(vma, &vvar_mapping))
    zap_page_range(vma, vma->vm_start, size);
    }

    + rcu_read_unlock();
    mmap_read_unlock(mm);
    return 0;
    }
    @@ -354,6 +358,7 @@ int map_vdso_once(const struct vdso_image *image, unsigned long addr)
    {
    struct mm_struct *mm = current->mm;
    struct vm_area_struct *vma;
    + MA_STATE(mas, &mm->mm_mt, 0, 0);

    mmap_write_lock(mm);
    /*
    @@ -363,13 +368,16 @@ int map_vdso_once(const struct vdso_image *image, unsigned long addr)
    * We could search vma near context.vdso, but it's a slowpath,
    * so let's explicitly check all VMAs to be completely sure.
    */
    - for (vma = mm->mmap; vma; vma = vma->vm_next) {
    + mas_lock(&mas);
    + mas_for_each(&mas, vma, ULONG_MAX) {
    if (vma_is_special_mapping(vma, &vdso_mapping) ||
    vma_is_special_mapping(vma, &vvar_mapping)) {
    + mas_unlock(&mas);
    mmap_write_unlock(mm);
    return -EEXIST;
    }
    }
    + mas_unlock(&mas);
    mmap_write_unlock(mm);

    return map_vdso(image, addr);
    --
    2.30.2
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