From e7fe7b5cae90cf85bb6fed5ec5d4c5cf311a4fe9 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 29 Nov 2017 16:10:14 -0800 Subject: mm: replace pud_write with pud_access_permitted in fault + gup paths 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 pud_write is must be referencing user-memory. [dan.j.williams@intel.com: fix powerpc compile error] Link: http://lkml.kernel.org/r/151129127237.37405.16073414520854722485.stgit@dwillia2-desk3.amr.corp.intel.com Link: http://lkml.kernel.org/r/151043110453.2842.2166049702068628177.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Cc: Dave Hansen Cc: "David S. Miller" Cc: Kirill A. Shutemov Cc: Martin Schwidefsky Cc: Heiko Carstens Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/huge_memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/huge_memory.c') diff --git a/mm/huge_memory.c b/mm/huge_memory.c index f22401fd83b5..4fe2491056a0 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1019,7 +1019,7 @@ struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr, assert_spin_locked(pud_lockptr(mm, pud)); - if (flags & FOLL_WRITE && !pud_write(*pud)) + if (!pud_access_permitted(*pud, flags & FOLL_WRITE)) return NULL; if (pud_present(*pud) && pud_devmap(*pud)) -- cgit v1.2.3 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/huge_memory.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'mm/huge_memory.c') diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 4fe2491056a0..05b729f45e8a 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -877,7 +877,7 @@ struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr, */ WARN_ONCE(flags & FOLL_COW, "mm: In follow_devmap_pmd with FOLL_COW set"); - if (flags & FOLL_WRITE && !pmd_write(*pmd)) + if (!pmd_access_permitted(*pmd, flags & FOLL_WRITE)) return NULL; if (pmd_present(*pmd) && pmd_devmap(*pmd)) @@ -1393,7 +1393,7 @@ out_unlock: */ static inline bool can_follow_write_pmd(pmd_t pmd, unsigned int flags) { - return pmd_write(pmd) || + return pmd_access_permitted(pmd, WRITE) || ((flags & FOLL_FORCE) && (flags & FOLL_COW) && pmd_dirty(pmd)); } -- cgit v1.2.3