[PATCH v4 08/13] mm: copy_pte_range() use pte_offset_map_rw_nolock()

[Muchun Song]

> On Sep 24, 2024, at 14:10, Qi Zheng <zhengqi.arch at bytedance.com> wrote:
> 
> In copy_pte_range(), we may modify the src_pte entry after holding the
> src_ptl, so convert it to using pte_offset_map_rw_nolock(). Since we
> already hold the exclusive mmap_lock, and the copy_pte_range() and
> retract_page_tables() are using vma->anon_vma to be exclusive, so the PTE
> page is stable, there is no need to get pmdval and do pmd_same() check.
> 
> Signed-off-by: Qi Zheng <zhengqi.arch at bytedance.com>

Reviewed-by: Muchun Song <muchun.song at linux.dev>