mainline inclusion from mainline-v6.17-rc2 commit 45d19b4b6c2d422771c29b83462d84afcbb33f01 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/ICRU7W Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- smaps_hugetlb_range() handles the pte without holdling ptl, and may be concurrenct with migration, leaing to BUG_ON in pfn_swap_entry_to_page(). The race is as follows. smaps_hugetlb_range migrate_pages huge_ptep_get remove_migration_ptes folio_unlock pfn_swap_entry_folio BUG_ON To fix it, hold ptl lock in smaps_hugetlb_range(). Link: https://lkml.kernel.org/r/20250724090958.455887-1-tujinjiang@huawei.com Link: https://lkml.kernel.org/r/20250724090958.455887-2-tujinjiang@huawei.com Fixes: 25ee01a2fca0 ("mm: hugetlb: proc: add hugetlb-related fields to /proc/PID/smaps") Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> Acked-by: David 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: Andrew Morton <akpm@linux-foundation.org> Conflicts: fs/proc/task_mmu.c [Context conflicts.] Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> --- fs/proc/task_mmu.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 9330da26e74a..a9b3d691a2db 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -709,7 +709,9 @@ static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask, struct mem_size_stats *mss = walk->private; struct vm_area_struct *vma = walk->vma; struct page *page = NULL; + spinlock_t *ptl; + ptl = huge_pte_lock(hstate_vma(vma), walk->mm, pte); if (pte_present(*pte)) { page = vm_normal_page(vma, addr, *pte); } else if (is_swap_pte(*pte)) { @@ -726,6 +728,7 @@ static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask, else mss->private_hugetlb += huge_page_size(hstate_vma(vma)); } + spin_unlock(ptl); return 0; } #endif /* HUGETLB_PAGE */ -- 2.43.0