Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751920AbdFIOYk (ORCPT ); Fri, 9 Jun 2017 10:24:40 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:45405 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751624AbdFIOVt (ORCPT ); Fri, 9 Jun 2017 10:21:49 -0400 From: Laurent Dufour To: paulmck@linux.vnet.ibm.com, peterz@infradead.org, akpm@linux-foundation.org, kirill@shutemov.name, ak@linux.intel.com, mhocko@kernel.org, dave@stgolabs.net, jack@suse.cz, Matthew Wilcox Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, haren@linux.vnet.ibm.com, khandual@linux.vnet.ibm.com, npiggin@gmail.com, bsingharora@gmail.com Subject: [RFC v4 11/20] mm/spf: Protect changes to vm_flags Date: Fri, 9 Jun 2017 16:21:00 +0200 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1497018069-17790-1-git-send-email-ldufour@linux.vnet.ibm.com> References: <1497018069-17790-1-git-send-email-ldufour@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17060914-0016-0000-0000-000004B95415 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17060914-0017-0000-0000-000027E980E0 Message-Id: <1497018069-17790-12-git-send-email-ldufour@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-06-09_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1706090251 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3686 Lines: 113 Protect VMA's flags change against the speculative page fault handler. Signed-off-by: Laurent Dufour --- fs/proc/task_mmu.c | 2 ++ mm/mempolicy.c | 2 ++ mm/mlock.c | 9 ++++++--- mm/mmap.c | 2 ++ mm/mprotect.c | 2 ++ 5 files changed, 14 insertions(+), 3 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index f0c8b33d99b1..9bc40620ba39 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1069,8 +1069,10 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, goto out_mm; } for (vma = mm->mmap; vma; vma = vma->vm_next) { + write_seqcount_begin(&vma->vm_sequence); vma->vm_flags &= ~VM_SOFTDIRTY; vma_set_page_prot(vma); + write_seqcount_end(&vma->vm_sequence); } downgrade_write(&mm->mmap_sem); break; diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 37d0b334bfe9..13d32c25226c 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -606,9 +606,11 @@ unsigned long change_prot_numa(struct vm_area_struct *vma, { int nr_updated; + write_seqcount_begin(&vma->vm_sequence); nr_updated = change_protection(vma, addr, end, PAGE_NONE, 0, 1); if (nr_updated) count_vm_numa_events(NUMA_PTE_UPDATES, nr_updated); + write_seqcount_end(&vma->vm_sequence); return nr_updated; } diff --git a/mm/mlock.c b/mm/mlock.c index b562b5523a65..30d9bfc61929 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -438,7 +438,9 @@ static unsigned long __munlock_pagevec_fill(struct pagevec *pvec, void munlock_vma_pages_range(struct vm_area_struct *vma, unsigned long start, unsigned long end) { + write_seqcount_begin(&vma->vm_sequence); vma->vm_flags &= VM_LOCKED_CLEAR_MASK; + write_seqcount_end(&vma->vm_sequence); while (start < end) { struct page *page; @@ -563,10 +565,11 @@ static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev, * It's okay if try_to_unmap_one unmaps a page just after we * set VM_LOCKED, populate_vma_page_range will bring it back. */ - - if (lock) + if (lock) { + write_seqcount_begin(&vma->vm_sequence); vma->vm_flags = newflags; - else + write_seqcount_end(&vma->vm_sequence); + } else munlock_vma_pages_range(vma, start, end); out: diff --git a/mm/mmap.c b/mm/mmap.c index 0cad4d9b71d8..c4a1e1aecef3 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1746,6 +1746,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr, out: perf_event_mmap(vma); + write_seqcount_begin(&vma->vm_sequence); vm_stat_account(mm, vm_flags, len >> PAGE_SHIFT); if (vm_flags & VM_LOCKED) { if (!((vm_flags & VM_SPECIAL) || is_vm_hugetlb_page(vma) || @@ -1768,6 +1769,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr, vma->vm_flags |= VM_SOFTDIRTY; vma_set_page_prot(vma); + write_seqcount_end(&vma->vm_sequence); return addr; diff --git a/mm/mprotect.c b/mm/mprotect.c index 8edd0d576254..1db5b0bf6952 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -345,6 +345,7 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, * vm_flags and vm_page_prot are protected by the mmap_sem * held in write mode. */ + write_seqcount_begin(&vma->vm_sequence); vma->vm_flags = newflags; dirty_accountable = vma_wants_writenotify(vma, vma->vm_page_prot); vma_set_page_prot(vma); @@ -360,6 +361,7 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, (newflags & VM_WRITE)) { populate_vma_page_range(vma, start, end, NULL); } + write_seqcount_end(&vma->vm_sequence); vm_stat_account(mm, oldflags, -nrpages); vm_stat_account(mm, newflags, nrpages); -- 2.7.4