From c7da82b894e9eef60a04a15f065a8502341bf13b Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 29 Nov 2017 16:10:18 -0800 Subject: mm: replace pmd_write with pmd_access_permitted in fault + gup paths MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The 'access_permitted' helper is used in the gup-fast path and goes beyond the simple _PAGE_RW check to also: - validate that the mapping is writable from a protection keys standpoint - validate that the pte has _PAGE_USER set since all fault paths where pmd_write is must be referencing user-memory. Link: http://lkml.kernel.org/r/151043111049.2842.15241454964150083466.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Cc: Dave Hansen Cc: Kirill A. Shutemov Cc: "Jérôme Glisse" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/hmm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'mm/hmm.c') diff --git a/mm/hmm.c b/mm/hmm.c index ea19742a5d60..93718a391611 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -391,11 +391,11 @@ again: if (pmd_protnone(pmd)) return hmm_vma_walk_clear(start, end, walk); - if (write_fault && !pmd_write(pmd)) + if (!pmd_access_permitted(pmd, write_fault)) return hmm_vma_walk_clear(start, end, walk); pfn = pmd_pfn(pmd) + pte_index(addr); - flag |= pmd_write(pmd) ? HMM_PFN_WRITE : 0; + flag |= pmd_access_permitted(pmd, WRITE) ? HMM_PFN_WRITE : 0; for (; addr < end; addr += PAGE_SIZE, i++, pfn++) pfns[i] = hmm_pfn_t_from_pfn(pfn) | flag; return 0; -- cgit