Unverified Commit 041ba628 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!12988 mm/mremap: fix move_normal_pmd/retract_page_tables race 

Merge Pull Request from: @ci-robot 
 
PR sync from: Kaixiong Yu <yukaixiong@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/GHREIRQELQKPQRFOQYXNIHC2UXOTFKFB/ 
 
https://gitee.com/src-openeuler/kernel/issues/IAZ7TE 
 
Link:https://gitee.com/openeuler/kernel/pulls/12988

 

Reviewed-by: default avatarZhang Peng <zhangpeng362@huawei.com>
Signed-off-by: default avatarZhang Peng <zhangpeng362@huawei.com>
parents 518cee10 aea07f4e

mm/mremap.c

+9 −2
Original line number Diff line number Diff line
@@ -240,6 +240,7 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr, 
{

	spinlock_t *old_ptl, *new_ptl;

	struct mm_struct *mm = vma->vm_mm;

	bool res = false;

	pmd_t pmd;



	if (!arch_supports_page_table_move())
@@ -279,19 +280,25 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr, 
	if (new_ptl != old_ptl)

		spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING);



	/* Clear the pmd */

	pmd = *old_pmd;



	/* Racing with collapse? */

	if (unlikely(!pmd_present(pmd) || pmd_leaf(pmd)))

		goto out_unlock;

	/* Clear the pmd */

	pmd_clear(old_pmd);

	res = true;



	VM_BUG_ON(!pmd_none(*new_pmd));



	pmd_populate(mm, new_pmd, pmd_pgtable(pmd));

	flush_tlb_range(vma, old_addr, old_addr + PMD_SIZE);

out_unlock:

	if (new_ptl != old_ptl)

		spin_unlock(new_ptl);

	spin_unlock(old_ptl);



	return true;

	return res;

}

#else

static inline bool move_normal_pmd(struct vm_area_struct *vma,