mm/mincore: hold PTL in mincore_hugetlb

Hold PTL in mincore_hugetlb() to avoid operating on stale page, as
mincore_pte_range() have done.

Link: https://lkml.kernel.org/r/20250724090958.455887-4-tujinjiang@huawei.com
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>

diff --git a/mm/mincore.c b/mm/mincore.c
index 42d6c9c8da86725b9c63a7841869f809c0f535c4..10dabefc3accb56f86e47e971ca95d8034c5c8ff 100644 (file)
--- a/mm/mincore.c
+++ b/mm/mincore.c
@@ -29,7 +29,9 @@ static int mincore_hugetlb(pte_t *pte, unsigned long hmask, unsigned long addr,
 #ifdef CONFIG_HUGETLB_PAGE
        unsigned char present;
        unsigned char *vec = walk->private;
+       spinlock_t *ptl;
 
+       ptl = huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte);
        /*
         * Hugepages under user process are always in RAM and never
         * swapped out, but theoretically it needs to be checked.
@@ -38,6 +40,7 @@ static int mincore_hugetlb(pte_t *pte, unsigned long hmask, unsigned long addr,
        for (; addr != end; vec++, addr += PAGE_SIZE)
                *vec = present;
        walk->private = vec;
+       spin_unlock(ptl);
 #else
        BUG();
 #endif