From 5c9d2d5c269c498aa9a546e8d2158a3e4142a1a2 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 29 Nov 2017 16:10:21 -0800 Subject: mm: replace pte_write with pte_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 pte_write is must be referencing user-memory. Link: http://lkml.kernel.org/r/151043111604.2842.8051684481794973100.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/gup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/gup.c') diff --git a/mm/gup.c b/mm/gup.c index dfcde13f289a..85cc822fd403 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -66,7 +66,7 @@ static int follow_pfn_pte(struct vm_area_struct *vma, unsigned long address, */ static inline bool can_follow_write_pte(pte_t pte, unsigned int flags) { - return pte_write(pte) || + return pte_access_permitted(pte, WRITE) || ((flags & FOLL_FORCE) && (flags & FOLL_COW) && pte_dirty(pte)); } -- cgit v1.2.3