Hi Punit,
On 22/08/17 11:42, Punit Agrawal wrote:
huge_pte_offset() was updated to correctly handle swap entries for
hugepages. With the addition of the size parameter, it is now possible
to disambiguate whether the request is for a regular hugepage or a
contiguous hugepage.
Fix huge_pte_offset() for contiguous hugepages by using the size to find
the correct page table entry.
Signed-off-by: Punit Agrawal <punit.agrawal@xxxxxxx>
Cc: David Woods <dwoods@xxxxxxxxxxxx>
---
arch/arm64/mm/hugetlbpage.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index 594232598cac..b95e24dc3477 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -214,6 +214,7 @@ pte_t *huge_pte_offset(struct mm_struct *mm,
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
+ pte_t *pte;
pgd = pgd_offset(mm, addr);
pr_debug("%s: addr:0x%lx pgd:%p\n", __func__, addr, pgd);
@@ -221,19 +222,29 @@ pte_t *huge_pte_offset(struct mm_struct *mm,
return NULL;
pud = pud_offset(pgd, addr);
- if (pud_none(*pud))
+ if (sz != PUD_SIZE && pud_none(*pud))
return NULL;
- /* swap or huge page */
- if (!pud_present(*pud) || pud_huge(*pud))
+ /* hugepage or swap? */
+ if (pud_huge(*pud) || !pud_present(*pud))
return (pte_t *)pud;
/* table; check the next level */
+ if (sz == CONT_PMD_SIZE)
+ addr &= CONT_PMD_MASK;
+
pmd = pmd_offset(pud, addr);
- if (pmd_none(*pmd))
+ if (!(sz == PMD_SIZE || sz == CONT_PMD_SIZE) &&
+ pmd_none(*pmd))
return NULL;
- if (!pmd_present(*pmd) || pmd_huge(*pmd))
+ if (pmd_huge(*pmd) || !pmd_present(*pmd))
return (pte_t *)pmd;
+ if (sz == CONT_PTE_SIZE) {
+ pte = pte_offset_kernel(
+ pmd, (addr & CONT_PTE_MASK));
+ return pte;
Nit: Looks like this is the only place the new variable pte is used.
Since we don't need to test its value, why not just write:
return pte_offset_kernel(pmd, (addr & CONT_PTE_MASK));
and get rid of the pte variable?
Cheers,
--
Julien Thierry
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