From 25591b07033663e09f5e60355fc5ec4d4aa53e63 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Wed, 10 Nov 2010 10:05:51 +0100 Subject: [PATCH] [S390] fix get_user_pages_fast The check for the _PAGE_RO bit in get_user_pages_fast for write==1 is the wrong way around. It must not be set for the fast path. Signed-off-by: Martin Schwidefsky --- arch/s390/mm/gup.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/arch/s390/mm/gup.c b/arch/s390/mm/gup.c index 38e641cdd977..45b405ca2567 100644 --- a/arch/s390/mm/gup.c +++ b/arch/s390/mm/gup.c @@ -20,18 +20,17 @@ static inline int gup_pte_range(pmd_t *pmdp, pmd_t pmd, unsigned long addr, unsigned long end, int write, struct page **pages, int *nr) { - unsigned long mask, result; + unsigned long mask; pte_t *ptep, pte; struct page *page; - result = write ? 0 : _PAGE_RO; - mask = result | _PAGE_INVALID | _PAGE_SPECIAL; + mask = (write ? _PAGE_RO : 0) | _PAGE_INVALID | _PAGE_SPECIAL; ptep = ((pte_t *) pmd_deref(pmd)) + pte_index(addr); do { pte = *ptep; barrier(); - if ((pte_val(pte) & mask) != result) + if ((pte_val(pte) & mask) != 0) return 0; VM_BUG_ON(!pfn_valid(pte_pfn(pte))); page = pte_page(pte); -- 2.20.1