From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f72.google.com (mail-pg0-f72.google.com [74.125.83.72]) by kanga.kvack.org (Postfix) with ESMTP id 603786B025E for ; Tue, 21 Nov 2017 14:16:09 -0500 (EST) Received: by mail-pg0-f72.google.com with SMTP id z184so13704182pgd.0 for ; Tue, 21 Nov 2017 11:16:09 -0800 (PST) Received: from mga07.intel.com (mga07.intel.com. [134.134.136.100]) by mx.google.com with ESMTPS id f3si1614315plb.92.2017.11.21.11.16.08 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 21 Nov 2017 11:16:08 -0800 (PST) Subject: [PATCH v3 3/5] mm: replace pud_write with pud_access_permitted in fault + gup paths From: Dan Williams Date: Tue, 21 Nov 2017 11:07:52 -0800 Message-ID: <151129127237.37405.16073414520854722485.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <151129125625.37405.15953656230804875212.stgit@dwillia2-desk3.amr.corp.intel.com> References: <151129125625.37405.15953656230804875212.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: linux-nvdimm@lists.01.org, Heiko Carstens , linux-mm@kvack.org, Dave Hansen , Martin Schwidefsky , "David S. Miller" , "Kirill A. Shutemov" 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. Cc: Dave Hansen Cc: "David S. Miller" Cc: Kirill A. Shutemov Cc: Martin Schwidefsky Cc: Heiko Carstens Signed-off-by: Dan Williams --- 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 86fe697e8bfb..9583f035ccb0 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1022,7 +1022,7 @@ 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 85e7a87da79f..24fbd60eb2b0 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; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org