From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id 67F332802A5 for ; Fri, 10 Nov 2017 19:53:03 -0500 (EST) Received: by mail-pf0-f197.google.com with SMTP id v78so8974953pfk.8 for ; Fri, 10 Nov 2017 16:53:03 -0800 (PST) Received: from mga14.intel.com (mga14.intel.com. [192.55.52.115]) by mx.google.com with ESMTPS id c193si10704464pfc.25.2017.11.10.16.53.02 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 10 Nov 2017 16:53:02 -0800 (PST) Subject: [PATCH 4/4] mm: replace pte_write with pte_access_permitted in fault + gup paths From: Dan Williams Date: Fri, 10 Nov 2017 16:44:47 -0800 Message-ID: <151036108744.32713.17165900700881849202.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <151036106541.32713.16875776773735515483.stgit@dwillia2-desk3.amr.corp.intel.com> References: <151036106541.32713.16875776773735515483.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Dave Hansen , =?utf-8?b?SsOpcsO0bWU=?= Glisse , "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 pte_write is must be referencing user-memory. Cc: Dave Hansen Cc: Kirill A. Shutemov Cc: "JA(C)rA'me Glisse" Signed-off-by: Dan Williams --- mm/gup.c | 2 +- mm/hmm.c | 4 ++-- mm/memory.c | 4 ++-- 3 files changed, 5 insertions(+), 5 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index b2b4d4263768..bb6542c47b08 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)); } diff --git a/mm/hmm.c b/mm/hmm.c index cbdd47bf6a48..3d2e49fd851a 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -456,11 +456,11 @@ static int hmm_vma_walk_pmd(pmd_t *pmdp, continue; } - if (write_fault && !pte_write(pte)) + if (!pte_access_permitted(pte, write_fault)) goto fault; pfns[i] = hmm_pfn_t_from_pfn(pte_pfn(pte)) | flag; - pfns[i] |= pte_write(pte) ? HMM_PFN_WRITE : 0; + pfns[i] |= pte_access_permitted(pte, WRITE) ? HMM_PFN_WRITE : 0; continue; fault: diff --git a/mm/memory.c b/mm/memory.c index 157fd4320bb3..a8cbc2c3e3c9 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3922,7 +3922,7 @@ static int handle_pte_fault(struct vm_fault *vmf) if (unlikely(!pte_same(*vmf->pte, entry))) goto unlock; if (vmf->flags & FAULT_FLAG_WRITE) { - if (!pte_write(entry)) + if (!pte_access_permitted(entry, WRITE)) return do_wp_page(vmf); entry = pte_mkdirty(entry); } @@ -4308,7 +4308,7 @@ int follow_phys(struct vm_area_struct *vma, goto out; pte = *ptep; - if ((flags & FOLL_WRITE) && !pte_write(pte)) + if (!pte_access_permitted(pte, flags & FOLL_WRITE)) goto unlock; *prot = pgprot_val(pte_pgprot(pte)); -- 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