Commit aa5a10b0 authored by Jinjiang Tu's avatar Jinjiang Tu Committed by Andrew Morton
Browse files

fs/proc/task_mmu: hold PTL in pagemap_hugetlb_range and gather_hugetlb_stats 

Hold PTL in pagemap_hugetlb_range() and gather_hugetlb_stats() to avoid
operating on stale page, as pagemap_pmd_range() and gather_pte_stats()
have done.

Link: https://lkml.kernel.org/r/20250724090958.455887-3-tujinjiang@huawei.com


Signed-off-by: default avatarJinjiang Tu <tujinjiang@huawei.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Brahmajit Das <brahmajit.xyz@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David Rientjes <rientjes@google.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joern Engel <joern@logfs.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 45d19b4b

fs/proc/task_mmu.c

+11 −3
Original line number Diff line number Diff line
@@ -2021,12 +2021,14 @@ static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask, 
	struct pagemapread *pm = walk->private;

	struct vm_area_struct *vma = walk->vma;

	u64 flags = 0, frame = 0;

	spinlock_t *ptl;

	int err = 0;

	pte_t pte;



	if (vma->vm_flags & VM_SOFTDIRTY)

		flags |= PM_SOFT_DIRTY;



	ptl = huge_pte_lock(hstate_vma(vma), walk->mm, ptep);

	pte = huge_ptep_get(walk->mm, addr, ptep);

	if (pte_present(pte)) {

		struct folio *folio = page_folio(pte_page(pte));
@@ -2054,11 +2056,12 @@ static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask, 


		err = add_to_pagemap(&pme, pm);

		if (err)

			return err;

			break;

		if (pm->show_pfn && (flags & PM_PRESENT))

			frame++;

	}



	spin_unlock(ptl);

	cond_resched();



	return err;
@@ -3132,17 +3135,22 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr, 
static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,

		unsigned long addr, unsigned long end, struct mm_walk *walk)

{

	pte_t huge_pte = huge_ptep_get(walk->mm, addr, pte);

	pte_t huge_pte;

	struct numa_maps *md;

	struct page *page;

	spinlock_t *ptl;



	ptl = huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte);

	huge_pte = huge_ptep_get(walk->mm, addr, pte);

	if (!pte_present(huge_pte))

		return 0;

		goto out;



	page = pte_page(huge_pte);



	md = walk->private;

	gather_stats(page, md, pte_dirty(huge_pte), 1);

out:

	spin_unlock(ptl);

	return 0;

}