diff options
Diffstat (limited to 'arch/x86/mm/gup.c')
| -rw-r--r-- | arch/x86/mm/gup.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c index 7d2542ad346a..6612d532e42e 100644 --- a/arch/x86/mm/gup.c +++ b/arch/x86/mm/gup.c @@ -95,7 +95,10 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr, } VM_BUG_ON(!pfn_valid(pte_pfn(pte))); page = pte_page(pte); - get_page(page); + if (unlikely(!try_get_page(page))) { + pte_unmap(ptep); + return 0; + } SetPageReferenced(page); pages[*nr] = page; (*nr)++; @@ -132,6 +135,8 @@ static noinline int gup_huge_pmd(pmd_t pmd, unsigned long addr, refs = 0; head = pmd_page(pmd); + if (WARN_ON_ONCE(page_ref_count(head) <= 0)) + return 0; page = head + ((addr & ~PMD_MASK) >> PAGE_SHIFT); do { VM_BUG_ON_PAGE(compound_head(page) != head, page); @@ -208,6 +213,8 @@ static noinline int gup_huge_pud(pud_t pud, unsigned long addr, refs = 0; head = pud_page(pud); + if (WARN_ON_ONCE(page_ref_count(head) <= 0)) + return 0; page = head + ((addr & ~PUD_MASK) >> PAGE_SHIFT); do { VM_BUG_ON_PAGE(compound_head(page) != head, page); |