From patchwork Fri Sep 8 18:06:51 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Dufour X-Patchwork-Id: 811789 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3xpm810Npkz9s7C for ; Sat, 9 Sep 2017 04:29:53 +1000 (AEST) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3xpm804ZVDzDqY8 for ; Sat, 9 Sep 2017 04:29:52 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=linux.vnet.ibm.com (client-ip=148.163.158.5; helo=mx0a-001b2d01.pphosted.com; envelope-from=ldufour@linux.vnet.ibm.com; receiver=) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3xplfN21yQzDrWS for ; Sat, 9 Sep 2017 04:07:39 +1000 (AEST) Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v88I4Xpb056552 for ; Fri, 8 Sep 2017 14:07:37 -0400 Received: from e06smtp12.uk.ibm.com (e06smtp12.uk.ibm.com [195.75.94.108]) by mx0b-001b2d01.pphosted.com with ESMTP id 2cuw4n1aed-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 08 Sep 2017 14:07:36 -0400 Received: from localhost by e06smtp12.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Fri, 8 Sep 2017 19:07:29 +0100 Received: from d06av24.portsmouth.uk.ibm.com (mk.ibm.com [9.149.105.60]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v88I7TVa29032614; Fri, 8 Sep 2017 18:07:29 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 673AE42041; Fri, 8 Sep 2017 19:03:56 +0100 (BST) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C72A44203F; Fri, 8 Sep 2017 19:03:53 +0100 (BST) Received: from nimbus.lab.toulouse-stg.fr.ibm.com (unknown [9.145.31.125]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Fri, 8 Sep 2017 19:03:53 +0100 (BST) 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 , benh@kernel.crashing.org, mpe@ellerman.id.au, paulus@samba.org, Thomas Gleixner , Ingo Molnar , hpa@zytor.com, Will Deacon , Sergey Senozhatsky Subject: [PATCH v3 07/20] mm: Cache some VMA fields in the vm_fault structure Date: Fri, 8 Sep 2017 20:06:51 +0200 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1504894024-2750-1-git-send-email-ldufour@linux.vnet.ibm.com> References: <1504894024-2750-1-git-send-email-ldufour@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17090818-0008-0000-0000-000004959E5E X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17090818-0009-0000-0000-00001E26A5EF Message-Id: <1504894024-2750-8-git-send-email-ldufour@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-09-08_12:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=2 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1709080270 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org, npiggin@gmail.com, linux-mm@kvack.org, Tim Chen , haren@linux.vnet.ibm.com, khandual@linux.vnet.ibm.com Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" When handling speculative page fault, the vma->vm_flags and vma->vm_page_prot fields are read once the page table lock is released. So there is no more guarantee that these fields would not change in our back. They will be saved in the vm_fault structure before the VMA is checked for changes. This patch also set the fields in hugetlb_no_page() and __collapse_huge_page_swapin even if it is not need for the callee. Signed-off-by: Laurent Dufour --- include/linux/mm.h | 6 ++++++ mm/hugetlb.c | 2 ++ mm/khugepaged.c | 2 ++ mm/memory.c | 38 ++++++++++++++++++++------------------ 4 files changed, 30 insertions(+), 18 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 46e769a5a7ab..5fd90ac31317 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -350,6 +350,12 @@ struct vm_fault { * page table to avoid allocation from * atomic context. */ + /* + * These entries are required when handling speculative page fault. + * This way the page handling is done using consistent field values. + */ + unsigned long vma_flags; + pgprot_t vma_page_prot; }; /* page entry size for vm->huge_fault() */ diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 424b0ef08a60..da82a86a4761 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3683,6 +3683,8 @@ static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, .vma = vma, .address = address, .flags = flags, + .vma_flags = vma->vm_flags, + .vma_page_prot = vma->vm_page_prot, /* * Hard to debug if it ends up being * used by a callee that assumes diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 56dd994c05d0..0525a0e74535 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -881,6 +881,8 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm, .flags = FAULT_FLAG_ALLOW_RETRY, .pmd = pmd, .pgoff = linear_page_index(vma, address), + .vma_flags = vma->vm_flags, + .vma_page_prot = vma->vm_page_prot, }; /* we only decide to swapin, if there is enough young ptes */ diff --git a/mm/memory.c b/mm/memory.c index f250e7c92948..f008042ab24e 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2556,7 +2556,7 @@ static int wp_page_copy(struct vm_fault *vmf) * Don't let another task, with possibly unlocked vma, * keep the mlocked page. */ - if (page_copied && (vma->vm_flags & VM_LOCKED)) { + if (page_copied && (vmf->vma_flags & VM_LOCKED)) { lock_page(old_page); /* LRU manipulation */ if (PageMlocked(old_page)) munlock_vma_page(old_page); @@ -2590,7 +2590,7 @@ static int wp_page_copy(struct vm_fault *vmf) */ int finish_mkwrite_fault(struct vm_fault *vmf) { - WARN_ON_ONCE(!(vmf->vma->vm_flags & VM_SHARED)); + WARN_ON_ONCE(!(vmf->vma_flags & VM_SHARED)); if (!pte_map_lock(vmf)) return VM_FAULT_RETRY; /* @@ -2692,7 +2692,7 @@ static int do_wp_page(struct vm_fault *vmf) * We should not cow pages in a shared writeable mapping. * Just mark the pages writable and/or call ops->pfn_mkwrite. */ - if ((vma->vm_flags & (VM_WRITE|VM_SHARED)) == + if ((vmf->vma_flags & (VM_WRITE|VM_SHARED)) == (VM_WRITE|VM_SHARED)) return wp_pfn_shared(vmf); @@ -2739,7 +2739,7 @@ static int do_wp_page(struct vm_fault *vmf) return VM_FAULT_WRITE; } unlock_page(vmf->page); - } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) == + } else if (unlikely((vmf->vma_flags & (VM_WRITE|VM_SHARED)) == (VM_WRITE|VM_SHARED))) { return wp_page_shared(vmf); } @@ -2975,7 +2975,7 @@ int do_swap_page(struct vm_fault *vmf) inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES); dec_mm_counter_fast(vma->vm_mm, MM_SWAPENTS); - pte = mk_pte(page, vma->vm_page_prot); + pte = mk_pte(page, vmf->vma_page_prot); if ((vmf->flags & FAULT_FLAG_WRITE) && reuse_swap_page(page, NULL)) { pte = maybe_mkwrite(pte_mkdirty(pte), vma); vmf->flags &= ~FAULT_FLAG_WRITE; @@ -2999,7 +2999,7 @@ int do_swap_page(struct vm_fault *vmf) swap_free(entry); if (mem_cgroup_swap_full(page) || - (vma->vm_flags & VM_LOCKED) || PageMlocked(page)) + (vmf->vma_flags & VM_LOCKED) || PageMlocked(page)) try_to_free_swap(page); unlock_page(page); if (page != swapcache) { @@ -3056,7 +3056,7 @@ static int do_anonymous_page(struct vm_fault *vmf) pte_t entry; /* File mapping without ->vm_ops ? */ - if (vma->vm_flags & VM_SHARED) + if (vmf->vma_flags & VM_SHARED) return VM_FAULT_SIGBUS; /* @@ -3080,7 +3080,7 @@ static int do_anonymous_page(struct vm_fault *vmf) if (!(vmf->flags & FAULT_FLAG_WRITE) && !mm_forbids_zeropage(vma->vm_mm)) { entry = pte_mkspecial(pfn_pte(my_zero_pfn(vmf->address), - vma->vm_page_prot)); + vmf->vma_page_prot)); if (!pte_map_lock(vmf)) return VM_FAULT_RETRY; if (!pte_none(*vmf->pte)) @@ -3113,8 +3113,8 @@ static int do_anonymous_page(struct vm_fault *vmf) */ __SetPageUptodate(page); - entry = mk_pte(page, vma->vm_page_prot); - if (vma->vm_flags & VM_WRITE) + entry = mk_pte(page, vmf->vma_page_prot); + if (vmf->vma_flags & VM_WRITE) entry = pte_mkwrite(pte_mkdirty(entry)); if (!pte_map_lock(vmf)) { @@ -3310,7 +3310,7 @@ static int do_set_pmd(struct vm_fault *vmf, struct page *page) for (i = 0; i < HPAGE_PMD_NR; i++) flush_icache_page(vma, page + i); - entry = mk_huge_pmd(page, vma->vm_page_prot); + entry = mk_huge_pmd(page, vmf->vma_page_prot); if (write) entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); @@ -3384,11 +3384,11 @@ int alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg, return VM_FAULT_NOPAGE; flush_icache_page(vma, page); - entry = mk_pte(page, vma->vm_page_prot); + entry = mk_pte(page, vmf->vma_page_prot); if (write) entry = maybe_mkwrite(pte_mkdirty(entry), vma); /* copy-on-write page */ - if (write && !(vma->vm_flags & VM_SHARED)) { + if (write && !(vmf->vma_flags & VM_SHARED)) { inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES); page_add_new_anon_rmap(page, vma, vmf->address, false); mem_cgroup_commit_charge(page, memcg, false, false); @@ -3427,7 +3427,7 @@ int finish_fault(struct vm_fault *vmf) /* Did we COW the page? */ if ((vmf->flags & FAULT_FLAG_WRITE) && - !(vmf->vma->vm_flags & VM_SHARED)) + !(vmf->vma_flags & VM_SHARED)) page = vmf->cow_page; else page = vmf->page; @@ -3681,7 +3681,7 @@ static int do_fault(struct vm_fault *vmf) ret = VM_FAULT_SIGBUS; else if (!(vmf->flags & FAULT_FLAG_WRITE)) ret = do_read_fault(vmf); - else if (!(vma->vm_flags & VM_SHARED)) + else if (!(vmf->vma_flags & VM_SHARED)) ret = do_cow_fault(vmf); else ret = do_shared_fault(vmf); @@ -3738,7 +3738,7 @@ static int do_numa_page(struct vm_fault *vmf) * accessible ptes, some can allow access by kernel mode. */ pte = ptep_modify_prot_start(vma->vm_mm, vmf->address, vmf->pte); - pte = pte_modify(pte, vma->vm_page_prot); + pte = pte_modify(pte, vmf->vma_page_prot); pte = pte_mkyoung(pte); if (was_writable) pte = pte_mkwrite(pte); @@ -3772,7 +3772,7 @@ static int do_numa_page(struct vm_fault *vmf) * Flag if the page is shared between multiple address spaces. This * is later used when determining whether to group tasks together */ - if (page_mapcount(page) > 1 && (vma->vm_flags & VM_SHARED)) + if (page_mapcount(page) > 1 && (vmf->vma_flags & VM_SHARED)) flags |= TNF_SHARED; last_cpupid = page_cpupid_last(page); @@ -3816,7 +3816,7 @@ static int wp_huge_pmd(struct vm_fault *vmf, pmd_t orig_pmd) return vmf->vma->vm_ops->huge_fault(vmf, PE_SIZE_PMD); /* COW handled on pte level: split pmd */ - VM_BUG_ON_VMA(vmf->vma->vm_flags & VM_SHARED, vmf->vma); + VM_BUG_ON_VMA(vmf->vma_flags & VM_SHARED, vmf->vma); __split_huge_pmd(vmf->vma, vmf->pmd, vmf->address, false, NULL); return VM_FAULT_FALLBACK; @@ -3963,6 +3963,8 @@ static int __handle_mm_fault(struct vm_area_struct *vma, unsigned long address, .flags = flags, .pgoff = linear_page_index(vma, address), .gfp_mask = __get_fault_gfp_mask(vma), + .vma_flags = vma->vm_flags, + .vma_page_prot = vma->vm_page_prot, }; unsigned int dirty = flags & FAULT_FLAG_WRITE; struct mm_struct *mm = vma->vm_mm;