{"id":811774,"url":"http://patchwork.ozlabs.org/api/1.2/patches/811774/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/1504894024-2750-2-git-send-email-ldufour@linux.vnet.ibm.com/","project":{"id":2,"url":"http://patchwork.ozlabs.org/api/1.2/projects/2/?format=json","name":"Linux PPC development","link_name":"linuxppc-dev","list_id":"linuxppc-dev.lists.ozlabs.org","list_email":"linuxppc-dev@lists.ozlabs.org","web_url":"https://github.com/linuxppc/wiki/wiki","scm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git","webscm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/","list_archive_url":"https://lore.kernel.org/linuxppc-dev/","list_archive_url_format":"https://lore.kernel.org/linuxppc-dev/{}/","commit_url_format":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?id={}"},"msgid":"<1504894024-2750-2-git-send-email-ldufour@linux.vnet.ibm.com>","list_archive_url":"https://lore.kernel.org/linuxppc-dev/1504894024-2750-2-git-send-email-ldufour@linux.vnet.ibm.com/","date":"2017-09-08T18:06:45","name":"[v3,01/20] mm: Dont assume page-table invariance during faults","commit_ref":null,"pull_url":null,"state":"not-applicable","archived":false,"hash":"eb65d4396c0e5116177125787cbcb65cb19321e7","submitter":{"id":40248,"url":"http://patchwork.ozlabs.org/api/1.2/people/40248/?format=json","name":"Laurent Dufour","email":"ldufour@linux.vnet.ibm.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/1504894024-2750-2-git-send-email-ldufour@linux.vnet.ibm.com/mbox/","series":[{"id":2269,"url":"http://patchwork.ozlabs.org/api/1.2/series/2269/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=2269","date":"2017-09-08T18:06:44","name":"Speculative page faults","version":3,"mbox":"http://patchwork.ozlabs.org/series/2269/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/811774/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/811774/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":["patchwork-incoming@ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Delivered-To":["patchwork-incoming@ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Received":["from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3])\n\t(using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xplmf1Q8lz9ryk\n\tfor ;\n\tSat, 9 Sep 2017 04:13:06 +1000 (AEST)","from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3])\n\tby lists.ozlabs.org (Postfix) with ESMTP id 3xplmf0SXRzDqY8\n\tfor ;\n\tSat, 9 Sep 2017 04:13:06 +1000 (AEST)","from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com\n\t[148.163.156.1])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256\n\tbits)) (No client certificate requested)\n\tby lists.ozlabs.org (Postfix) with ESMTPS id 3xplf04WGqzDrVj\n\tfor ;\n\tSat, 9 Sep 2017 04:07:20 +1000 (AEST)","from pps.filterd (m0098410.ppops.net [127.0.0.1])\n\tby mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id\n\tv88I6hxs050482\n\tfor ; Fri, 8 Sep 2017 14:07:18 -0400","from e06smtp13.uk.ibm.com (e06smtp13.uk.ibm.com [195.75.94.109])\n\tby mx0a-001b2d01.pphosted.com with ESMTP id 2cux35p8fs-1\n\t(version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT)\n\tfor ; Fri, 08 Sep 2017 14:07:18 -0400","from localhost\n\tby e06smtp13.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use\n\tOnly! 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Violators will be prosecuted; \n\tFri, 8 Sep 2017 19:07:10 +0100","from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com\n\t[9.149.105.60])\n\tby b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with\n\tESMTP id v88I7Asb26476672; Fri, 8 Sep 2017 18:07:10 GMT","from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 446ED4203F;\n\tFri, 8 Sep 2017 19:03:37 +0100 (BST)","from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 7C0DA42042;\n\tFri, 8 Sep 2017 19:03:35 +0100 (BST)","from nimbus.lab.toulouse-stg.fr.ibm.com (unknown [9.145.31.125])\n\tby d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP;\n\tFri, 8 Sep 2017 19:03:35 +0100 (BST)"],"Authentication-Results":"ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=linux.vnet.ibm.com\n\t(client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com;\n\tenvelope-from=ldufour@linux.vnet.ibm.com; receiver=)","From":"Laurent Dufour ","To":"paulmck@linux.vnet.ibm.com, peterz@infradead.org,\n\takpm@linux-foundation.org, kirill@shutemov.name, ak@linux.intel.com, \n\tmhocko@kernel.org, dave@stgolabs.net, jack@suse.cz,\n\tMatthew Wilcox , benh@kernel.crashing.org,\n\tmpe@ellerman.id.au, paulus@samba.org,\n\tThomas Gleixner , Ingo Molnar , \n\thpa@zytor.com, Will Deacon ,\n\tSergey Senozhatsky ","Subject":"[PATCH v3 01/20] mm: Dont assume page-table invariance during faults","Date":"Fri, 8 Sep 2017 20:06:45 +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":"17090818-0012-0000-0000-00000577A9A2","X-IBM-AV-DETECTION":"SAVI=unused REMOTE=unused XFE=unused","x-cbparentid":"17090818-0013-0000-0000-000018F0B11D","Message-Id":"<1504894024-2750-2-git-send-email-ldufour@linux.vnet.ibm.com>","X-Proofpoint-Virus-Version":"vendor=fsecure engine=2.50.10432:, ,\n\tdefinitions=2017-09-08_12:, , signatures=0","X-Proofpoint-Spam-Details":"rule=outbound_notspam policy=outbound score=0\n\tspamscore=0 suspectscore=2\n\tmalwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam\n\tadjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000\n\tdefinitions=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\n\t","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Cc":"linuxppc-dev@lists.ozlabs.org, x86@kernel.org,\n\tlinux-kernel@vger.kernel.org, npiggin@gmail.com, linux-mm@kvack.org,\n\tTim Chen , \n\tharen@linux.vnet.ibm.com, khandual@linux.vnet.ibm.com","Errors-To":"linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org","Sender":"\"Linuxppc-dev\"\n\t"},"content":"From: Peter Zijlstra \n\nOne of the side effects of speculating on faults (without holding\nmmap_sem) is that we can race with free_pgtables() and therefore we\ncannot assume the page-tables will stick around.\n\nRemove the reliance on the pte pointer.\n\nSigned-off-by: Peter Zijlstra (Intel) \n---\n mm/memory.c | 29 -----------------------------\n 1 file changed, 29 deletions(-)","diff":"diff --git a/mm/memory.c b/mm/memory.c\nindex ec4e15494901..30bccfa00630 100644\n--- a/mm/memory.c\n+++ b/mm/memory.c\n@@ -2270,30 +2270,6 @@ int apply_to_page_range(struct mm_struct *mm, unsigned long addr,\n }\n EXPORT_SYMBOL_GPL(apply_to_page_range);\n \n-/*\n- * handle_pte_fault chooses page fault handler according to an entry which was\n- * read non-atomically. Before making any commitment, on those architectures\n- * or configurations (e.g. i386 with PAE) which might give a mix of unmatched\n- * parts, do_swap_page must check under lock before unmapping the pte and\n- * proceeding (but do_wp_page is only called after already making such a check;\n- * and do_anonymous_page can safely check later on).\n- */\n-static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd,\n-\t\t\t\tpte_t *page_table, pte_t orig_pte)\n-{\n-\tint same = 1;\n-#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)\n-\tif (sizeof(pte_t) > sizeof(unsigned long)) {\n-\t\tspinlock_t *ptl = pte_lockptr(mm, pmd);\n-\t\tspin_lock(ptl);\n-\t\tsame = pte_same(*page_table, orig_pte);\n-\t\tspin_unlock(ptl);\n-\t}\n-#endif\n-\tpte_unmap(page_table);\n-\treturn same;\n-}\n-\n static inline void cow_user_page(struct page *dst, struct page *src, unsigned long va, struct vm_area_struct *vma)\n {\n \tdebug_dma_assert_idle(src);\n@@ -2854,11 +2830,6 @@ int do_swap_page(struct vm_fault *vmf)\n \n \tif (vma_readahead)\n \t\tpage = swap_readahead_detect(vmf, &swap_ra);\n-\tif (!pte_unmap_same(vma->vm_mm, vmf->pmd, vmf->pte, vmf->orig_pte)) {\n-\t\tif (page)\n-\t\t\tput_page(page);\n-\t\tgoto out;\n-\t}\n \n \tentry = pte_to_swp_entry(vmf->orig_pte);\n \tif (unlikely(non_swap_entry(entry))) {\n","prefixes":["v3","01/20"]}