Re: [PATCH v4 08/13] mm: copy_pte_range() use pte_offset_map_rw_nolock()
From: Muchun Song
Date: Tue Sep 24 2024 - 03:36:28 EST
> On Sep 24, 2024, at 14:10, Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx>
Reviewed-by: Muchun Song <muchun.song@xxxxxxxxx>