From 1623717b057f904d558eb0489fbd592a18750c1e Mon Sep 17 00:00:00 2001
From: Jinjiang Tu <tujinjiang@huawei.com>
Date: Thu, 24 Jul 2025 17:09:58 +0800
Subject: [PATCH] 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>
---
 mm/mincore.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mm/mincore.c b/mm/mincore.c
index 42d6c9c8da86..10dabefc3acc 100644
--- 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
-- 
2.47.2