When memory failure is enabled, a poisoned hugepage pte is marked as a swap entry. huge_pte_offset() does not return the poisoned page table entries when it encounters PUD/PMD hugepages.
This behaviour of huge_pte_offset() leads to error such as below when munmap is called on poisoned hugepages. [ 344.165544] mm/pgtable-generic.c:33: bad pmd 000000083af00074. Fix huge_pte_offset() to return the poisoned pte which is then appropriately handled by the generic layer code. Signed-off-by: Punit Agrawal <[email protected]> Acked-by: Steve Capper <[email protected]> Reviewed-by: Catalin Marinas <[email protected]> Cc: David Woods <[email protected]> Tested-by: Manoj Iyer <[email protected]> --- arch/arm64/include/asm/pgtable.h | 2 +- arch/arm64/mm/hugetlbpage.c | 29 ++++++++++------------------- 2 files changed, 11 insertions(+), 20 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index c213fdbd056c..6eae342ced6b 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -441,7 +441,7 @@ static inline phys_addr_t pmd_page_paddr(pmd_t pmd) #define pud_none(pud) (!pud_val(pud)) #define pud_bad(pud) (!(pud_val(pud) & PUD_TABLE_BIT)) -#define pud_present(pud) (pud_val(pud)) +#define pud_present(pud) pte_present(pud_pte(pud)) static inline void set_pud(pud_t *pudp, pud_t pud) { diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index 7514a000e361..69b8200b1cfd 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -136,36 +136,27 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) { pgd_t *pgd; pud_t *pud; - pmd_t *pmd = NULL; - pte_t *pte = NULL; + pmd_t *pmd; 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)) return NULL; - - if (pud_huge(*pud)) + /* swap or huge page */ + if (!pud_present(*pud) || pud_huge(*pud)) return (pte_t *)pud; + /* table; check the next level */ + pmd = pmd_offset(pud, addr); - if (!pmd_present(*pmd)) + if (pmd_none(*pmd)) return NULL; - - if (pte_cont(pmd_pte(*pmd))) { - pmd = pmd_offset( - pud, (addr & CONT_PMD_MASK)); - return (pte_t *)pmd; - } - if (pmd_huge(*pmd)) + if (!pmd_present(*pmd) || pmd_huge(*pmd)) return (pte_t *)pmd; - pte = pte_offset_kernel(pmd, addr); - if (pte_present(*pte) && pte_cont(*pte)) { - pte = pte_offset_kernel( - pmd, (addr & CONT_PTE_MASK)); - return pte; - } + return NULL; } -- 2.11.0
