On Sep 24, 2024, at 14:10, Qi Zheng [off-list ref] 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 <redacted>

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