From: Punit Agrawal <punit.agrawal@arm.com>
To: catalin.marinas@arm.com, will.deacon@arm.com,
akpm@linux-foundation.org, mark.rutland@arm.com
Cc: Punit Agrawal <punit.agrawal@arm.com>,
linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, tbaicar@codeaurora.org,
kirill.shutemov@linux.intel.com, mike.kravetz@oracle.com,
hillf.zj@alibaba-inc.com, steve.capper@arm.com,
David Woods <dwoods@mellanox.com>
Subject: [PATCH v2 2/9] arm64: hugetlbpages: Support handling swap entries in huge_pte_offset()
Date: Wed, 5 Apr 2017 14:37:15 +0100 [thread overview]
Message-ID: <20170405133722.6406-3-punit.agrawal@arm.com> (raw)
In-Reply-To: <20170405133722.6406-1-punit.agrawal@arm.com>
huge_pte_offset() does not correctly handle poisoned or migration page
table entries. It returns NULL instead of the offset when it encounters
a swap entry. This leads to errors such as
[ 344.165544] mm/pgtable-generic.c:33: bad pmd 000000083af00074.
in the kernel log when unmapping memory on process exit.
huge_pte_offset() is now provided with the size of the hugepage being
accessed. Use the size to find the correct page table entry to return.
Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Cc: David Woods <dwoods@mellanox.com>
---
arch/arm64/mm/hugetlbpage.c | 30 +++++++++++++++---------------
1 file changed, 15 insertions(+), 15 deletions(-)
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index 1bc08ae49e6a..009648c4500f 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -194,36 +194,36 @@ pte_t *huge_pte_offset(struct mm_struct *mm,
{
pgd_t *pgd;
pud_t *pud;
- pmd_t *pmd = NULL;
- pte_t *pte = NULL;
+ pmd_t *pmd;
+ pte_t *pte;
pgd = pgd_offset(mm, addr);
pr_debug("%s: addr:0x%lx pgd:%p\n", __func__, addr, pgd);
if (!pgd_present(*pgd))
return NULL;
+
pud = pud_offset(pgd, addr);
- if (!pud_present(*pud))
+ if (pud_none(*pud) && sz != PUD_SIZE)
return NULL;
-
- if (pud_huge(*pud))
+ else if (!pud_table(*pud))
return (pte_t *)pud;
+
+ if (sz == CONT_PMD_SIZE)
+ addr &= CONT_PMD_MASK;
+
pmd = pmd_offset(pud, addr);
- if (!pmd_present(*pmd))
+ if (pmd_none(*pmd) &&
+ !(sz == PMD_SIZE || sz == CONT_PMD_SIZE))
return NULL;
-
- if (pte_cont(pmd_pte(*pmd))) {
- pmd = pmd_offset(
- pud, (addr & CONT_PMD_MASK));
- return (pte_t *)pmd;
- }
- if (pmd_huge(*pmd))
+ else if (!pmd_table(*pmd))
return (pte_t *)pmd;
- pte = pte_offset_kernel(pmd, addr);
- if (pte_present(*pte) && pte_cont(*pte)) {
+
+ if (sz == CONT_PTE_SIZE) {
pte = pte_offset_kernel(
pmd, (addr & CONT_PTE_MASK));
return pte;
}
+
return NULL;
}
--
2.11.0
--
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next prev parent reply other threads:[~2017-04-05 13:38 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-05 13:37 [PATCH v2 0/9] Support swap entries for contiguous pte hugepages Punit Agrawal
2017-04-05 13:37 ` [PATCH v2 1/9] mm/hugetlb: add size parameter to huge_pte_offset() Punit Agrawal
2017-04-05 13:37 ` Punit Agrawal [this message]
2017-04-05 13:37 ` [PATCH v2 3/9] mm/hugetlb: Allow architectures to override huge_pte_clear() Punit Agrawal
2017-04-05 13:37 ` [PATCH v2 4/9] arm64: hugetlb: Override huge_pte_clear() to support contiguous hugepages Punit Agrawal
2017-04-06 5:37 ` kbuild test robot
2017-04-05 13:37 ` [PATCH v2 5/9] mm/hugetlb: Introduce set_huge_swap_pte_at() helper Punit Agrawal
2017-04-05 13:37 ` [PATCH v2 6/9] mm: rmap: Use correct helper when poisoning hugepages Punit Agrawal
2017-04-06 1:25 ` kbuild test robot
2017-04-05 13:37 ` [PATCH v2 7/9] arm64: hugetlb: Override set_huge_swap_pte_at() to support contiguous hugepages Punit Agrawal
2017-04-05 13:37 ` [PATCH v2 8/9] arm64: hwpoison: add VM_FAULT_HWPOISON[_LARGE] handling Punit Agrawal
2017-04-05 13:37 ` [PATCH v2 9/9] arm64: kconfig: allow support for memory failure handling Punit Agrawal
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