On 12/1/21 15:30, Liam Howlett wrote:
> From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
>
> The VMA iterator is faster than the linked list and removing the linked
> list will shrink the vm_area_struct.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
> ---
> kernel/fork.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/fork.c b/kernel/fork.c
> index 3493117c8d35..6de302e93519 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -1228,13 +1228,16 @@ int replace_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file)
> /* Forbid mm->exe_file change if old file still mapped. */
> old_exe_file = get_mm_exe_file(mm);
> if (old_exe_file) {
> + VMA_ITERATOR(vmi, mm, 0);
> mmap_read_lock(mm);
> - for (vma = mm->mmap; vma && !ret; vma = vma->vm_next) {
> + for_each_vma(vmi, vma) {
> if (!vma->vm_file)
> continue;
> if (path_equal(&vma->vm_file->f_path,
> - &old_exe_file->f_path))
> + &old_exe_file->f_path)) {
> ret = -EBUSY;
> + break;
> + }
> }
> mmap_read_unlock(mm);
> fput(old_exe_file);
