diff options
Diffstat (limited to 'arch/x86/mm/gup.c')
| -rw-r--r-- | arch/x86/mm/gup.c | 37 |
1 files changed, 21 insertions, 16 deletions
diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c index 99c7805a9693..1f3b6ef105cd 100644 --- a/arch/x86/mm/gup.c +++ b/arch/x86/mm/gup.c @@ -106,32 +106,35 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end, int write, struct page **pages, int *nr) { struct dev_pagemap *pgmap = NULL; - int nr_start = *nr; - pte_t *ptep; + int nr_start = *nr, ret = 0; + pte_t *ptep, *ptem; - ptep = pte_offset_map(&pmd, addr); + /* + * Keep the original mapped PTE value (ptem) around since we + * might increment ptep off the end of the page when finishing + * our loop iteration. + */ + ptem = ptep = pte_offset_map(&pmd, addr); do { pte_t pte = gup_get_pte(ptep); struct page *page; /* Similar to the PMD case, NUMA hinting must take slow path */ - if (pte_protnone(pte)) { - pte_unmap(ptep); - return 0; - } + if (pte_protnone(pte)) + break; + + if (!pte_allows_gup(pte_val(pte), write)) + break; if (pte_devmap(pte)) { pgmap = get_dev_pagemap(pte_pfn(pte), pgmap); if (unlikely(!pgmap)) { undo_dev_pagemap(nr, nr_start, pages); - pte_unmap(ptep); - return 0; + break; } - } else if (!pte_allows_gup(pte_val(pte), write) || - pte_special(pte)) { - pte_unmap(ptep); - return 0; - } + } else if (pte_special(pte)) + break; + VM_BUG_ON(!pfn_valid(pte_pfn(pte))); page = pte_page(pte); get_page(page); @@ -141,9 +144,11 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr, (*nr)++; } while (ptep++, addr += PAGE_SIZE, addr != end); - pte_unmap(ptep - 1); + if (addr == end) + ret = 1; + pte_unmap(ptem); - return 1; + return ret; } static inline void get_head_page_multiple(struct page *page, int nr) |