stable inclusion from stable-v5.10.228 commit 417d5838ca73c6331ae2fe692fab6c25c00d9a0b category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IAXWWM

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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commit 7528c4fb1237512ee18049f852f014eba80bbe8d upstream.

I got a bad pud error and lost a 1GB HugeTLB when calling swapoff. The problem can be reproduced by the following steps:

1. Allocate an anonymous 1GB HugeTLB and some other anonymous memory. 2. Swapout the above anonymous memory. 3. run swapoff and we will get a bad pud error in kernel message:

mm/pgtable-generic.c:42: bad pud 00000000743d215d(84000001400000e7)

We can tell that pud_clear_bad is called by pud_none_or_clear_bad in unuse_pud_range() by ftrace. And therefore the HugeTLB pages will never be freed because we lost it from page table. We can skip HugeTLB pages for unuse_vma to fix it.

Link: https://lkml.kernel.org/r/20241015014521.570237-1-liushixin2@huawei.com Fixes: 0fe6e20b9c4c ("hugetlb, rmap: add reverse mapping for hugepage") Signed-off-by: Liu Shixin liushixin2@huawei.com Acked-by: Muchun Song muchun.song@linux.dev Cc: Naoya Horiguchi nao.horiguchi@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Liu Shixin liushixin2@huawei.com --- mm/swapfile.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/swapfile.c b/mm/swapfile.c index e46a2ca1c679a..edcf6335aba4d 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2144,7 +2144,7 @@ static int unuse_mm(struct mm_struct *mm, unsigned int type,

mmap_read_lock(mm); for (vma = mm->mmap; vma; vma = vma->vm_next) { - if (vma->anon_vma) { + if (vma->anon_vma && !is_vm_hugetlb_page(vma)) { ret = unuse_vma(vma, type, frontswap, fs_pages_to_unuse); if (ret)