From e7fe7b5cae90cf85bb6fed5ec5d4c5cf311a4fe9 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 29 Nov 2017 16:10:14 -0800 Subject: [PATCH] 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 --- arch/s390/include/asm/pgtable.h | 6 ++++++ arch/sparc/mm/gup.c | 2 +- mm/huge_memory.c | 2 +- mm/memory.c | 2 +- 4 files changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 0a6b0286c32e..57d7bc92e0b8 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -1264,6 +1264,12 @@ static inline pud_t pud_mkwrite(pud_t pud) return pud; } +#define pud_write pud_write +static inline int pud_write(pud_t pud) +{ + return (pud_val(pud) & _REGION3_ENTRY_WRITE) != 0; +} + static inline pud_t pud_mkclean(pud_t pud) { if (pud_large(pud)) { diff --git a/arch/sparc/mm/gup.c b/arch/sparc/mm/gup.c index 5335ba3c850e..5ae2d0a01a70 100644 --- a/arch/sparc/mm/gup.c +++ b/arch/sparc/mm/gup.c @@ -114,7 +114,7 @@ static int gup_huge_pud(pud_t *pudp, pud_t pud, unsigned long addr, if (!(pud_val(pud) & _PAGE_VALID)) return 0; - if (write && !pud_write(pud)) + if (!pud_access_permitted(pud, write)) return 0; refs = 0; 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)) diff --git a/mm/memory.c b/mm/memory.c index b10c1d26f675..25d283d46ea3 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4013,7 +4013,7 @@ static int __handle_mm_fault(struct vm_area_struct *vma, unsigned long address, /* NUMA case for anonymous PUDs would go here */ - if (dirty && !pud_write(orig_pud)) { + if (dirty && !pud_access_permitted(orig_pud, WRITE)) { ret = wp_huge_pud(&vmf, orig_pud); if (!(ret & VM_FAULT_FALLBACK)) return ret; -- 2.45.2