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Message-Id: <20220815180510.133372771@linuxfoundation.org>
Date: Mon, 15 Aug 2022 20:02:02 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Miaohe Lin <linmiaohe@...wei.com>,
David Hildenbrand <david@...hat.com>,
Alistair Popple <apopple@...dia.com>,
Christoph Hellwig <hch@....de>,
Christoph Lameter <cl@...ux.com>,
David Howells <dhowells@...hat.com>,
Huang Ying <ying.huang@...el.com>,
kernel test robot <lkp@...el.com>,
Mike Kravetz <mike.kravetz@...cle.com>,
Muchun Song <songmuchun@...edance.com>,
Oscar Salvador <osalvador@...e.de>,
Peter Xu <peterx@...hat.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.19 0766/1157] mm/migration: fix potential pte_unmap on an not mapped pte
From: Miaohe Lin <linmiaohe@...wei.com>
[ Upstream commit ad1ac596e8a8c4b06715dfbd89853eb73c9886b2 ]
__migration_entry_wait and migration_entry_wait_on_locked assume pte is
always mapped from caller. But this is not the case when it's called from
migration_entry_wait_huge and follow_huge_pmd. Add a hugetlbfs variant
that calls hugetlb_migration_entry_wait(ptep == NULL) to fix this issue.
Link: https://lkml.kernel.org/r/20220530113016.16663-5-linmiaohe@huawei.com
Fixes: 30dad30922cc ("mm: migration: add migrate_entry_wait_huge()")
Signed-off-by: Miaohe Lin <linmiaohe@...wei.com>
Suggested-by: David Hildenbrand <david@...hat.com>
Reviewed-by: David Hildenbrand <david@...hat.com>
Cc: Alistair Popple <apopple@...dia.com>
Cc: Christoph Hellwig <hch@....de>
Cc: Christoph Lameter <cl@...ux.com>
Cc: David Howells <dhowells@...hat.com>
Cc: Huang Ying <ying.huang@...el.com>
Cc: kernel test robot <lkp@...el.com>
Cc: Mike Kravetz <mike.kravetz@...cle.com>
Cc: Muchun Song <songmuchun@...edance.com>
Cc: Oscar Salvador <osalvador@...e.de>
Cc: Peter Xu <peterx@...hat.com>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
include/linux/swapops.h | 12 ++++++++----
mm/hugetlb.c | 4 ++--
mm/migrate.c | 23 +++++++++++++++++++----
3 files changed, 29 insertions(+), 10 deletions(-)
diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index f24775b41880..bb7afd03a324 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -244,8 +244,10 @@ extern void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
spinlock_t *ptl);
extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
unsigned long address);
-extern void migration_entry_wait_huge(struct vm_area_struct *vma,
- struct mm_struct *mm, pte_t *pte);
+#ifdef CONFIG_HUGETLB_PAGE
+extern void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl);
+extern void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *pte);
+#endif
#else
static inline swp_entry_t make_readable_migration_entry(pgoff_t offset)
{
@@ -271,8 +273,10 @@ static inline void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
spinlock_t *ptl) { }
static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
unsigned long address) { }
-static inline void migration_entry_wait_huge(struct vm_area_struct *vma,
- struct mm_struct *mm, pte_t *pte) { }
+#ifdef CONFIG_HUGETLB_PAGE
+static inline void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl) { }
+static inline void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *pte) { }
+#endif
static inline int is_writable_migration_entry(swp_entry_t entry)
{
return 0;
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index b7f007399be2..474bfbe9929e 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5707,7 +5707,7 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
*/
entry = huge_ptep_get(ptep);
if (unlikely(is_hugetlb_entry_migration(entry))) {
- migration_entry_wait_huge(vma, mm, ptep);
+ migration_entry_wait_huge(vma, ptep);
return 0;
} else if (unlikely(is_hugetlb_entry_hwpoisoned(entry)))
return VM_FAULT_HWPOISON_LARGE |
@@ -6933,7 +6933,7 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address,
} else {
if (is_hugetlb_entry_migration(pte)) {
spin_unlock(ptl);
- __migration_entry_wait(mm, (pte_t *)pmd, ptl);
+ __migration_entry_wait_huge((pte_t *)pmd, ptl);
goto retry;
}
/*
diff --git a/mm/migrate.c b/mm/migrate.c
index 29b9faed4136..a480f54016b3 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -315,13 +315,28 @@ void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
__migration_entry_wait(mm, ptep, ptl);
}
-void migration_entry_wait_huge(struct vm_area_struct *vma,
- struct mm_struct *mm, pte_t *pte)
+#ifdef CONFIG_HUGETLB_PAGE
+void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl)
{
- spinlock_t *ptl = huge_pte_lockptr(hstate_vma(vma), mm, pte);
- __migration_entry_wait(mm, pte, ptl);
+ pte_t pte;
+
+ spin_lock(ptl);
+ pte = huge_ptep_get(ptep);
+
+ if (unlikely(!is_hugetlb_entry_migration(pte)))
+ spin_unlock(ptl);
+ else
+ migration_entry_wait_on_locked(pte_to_swp_entry(pte), NULL, ptl);
}
+void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *pte)
+{
+ spinlock_t *ptl = huge_pte_lockptr(hstate_vma(vma), vma->vm_mm, pte);
+
+ __migration_entry_wait_huge(pte, ptl);
+}
+#endif
+
#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd)
{
--
2.35.1
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