From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,HK_RANDOM_FROM,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F7D3C433E0 for ; Wed, 10 Mar 2021 06:11:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2E7BE64FF6 for ; Wed, 10 Mar 2021 06:11:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229712AbhCJGLT convert rfc822-to-8bit (ORCPT ); Wed, 10 Mar 2021 01:11:19 -0500 Received: from mail.kingsoft.com ([114.255.44.145]:14202 "EHLO mail.kingsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229543AbhCJGKr (ORCPT ); Wed, 10 Mar 2021 01:10:47 -0500 X-AuditID: 0a580155-1f5ff7000005482e-70-60485b66f134 Received: from mail.kingsoft.com (localhost [10.88.1.32]) (using TLS with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) by mail.kingsoft.com (SMG-2-NODE-85) with SMTP id 8A.93.18478.66B58406; Wed, 10 Mar 2021 13:38:46 +0800 (HKT) Received: from alex-virtual-machine (172.16.253.254) by KSBJMAIL2.kingsoft.cn (10.88.1.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 10 Mar 2021 14:10:43 +0800 Date: Wed, 10 Mar 2021 14:10:42 +0800 From: Aili Yao To: "Luck, Tony" CC: "HORIGUCHI =?UTF-8?B?TkFPWUE=?=(=?UTF-8?B?5aCA5Y+j44CA55u05Lmf?=)" , Oscar Salvador , "david@redhat.com" , "akpm@linux-foundation.org" , "bp@alien8.de" , "tglx@linutronix.de" , "mingo@redhat.com" , "hpa@zytor.com" , "x86@kernel.org" , "linux-edac@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "yangfeng1@kingsoft.com" , Subject: Re: [PATCH] mm,hwpoison: return -EBUSY when page already poisoned Message-ID: <20210310141042.4db9ea29@alex-virtual-machine> In-Reply-To: References: <20210225181542.GA178925@agluck-desk2.amr.corp.intel.com> <20210226021907.GA27861@hori.linux.bs1.fc.nec.co.jp> <20210226105915.6cf7d2b8@alex-virtual-machine> <20210303033953.GA205389@agluck-desk2.amr.corp.intel.com> <20210303115710.2e9f8e23@alex-virtual-machine> <20210303163912.3d508e0f@alex-virtual-machine> <1a78e9abdc134e35a5efcbf6b2fd2263@intel.com> <20210304101653.546a9da1@alex-virtual-machine> <20210304121941.667047c3@alex-virtual-machine> <20210304144524.795872d7@alex-virtual-machine> <20210304235720.GA215567@agluck-desk2.amr.corp.intel.com> <20210305093016.40c87375@alex-virtual-machine> Organization: kingsoft X-Mailer: Claws Mail 3.17.5 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 8BIT X-Originating-IP: [172.16.253.254] X-ClientProxiedBy: KSBJMAIL1.kingsoft.cn (10.88.1.31) To KSBJMAIL2.kingsoft.cn (10.88.1.32) X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprNIsWRmVeSWpSXmKPExsXCFcGooJsW7ZFgcOGGpMWc9WvYLD5v+Mdm 8XX9L2aLaRvFLS6camCyuLxrDpvFvTX/WS0uHVjAZHGx8QCjxZlpRRabN01ltnhz4R6LxY8N j1kdeD2+t/axeCze85LJY9OqTjaPTZ8msXu8O3eO3ePEjN8sHi+ubmTxeL/vKpvH5tPVHp83 yXmcaPnCGsAdxWWTkpqTWZZapG+XwJXx7fgK5oIb6hXbT7UwNjB+luti5OSQEDCRmHR3CmsX IxeHkMB0JonFf+8zQjivGCWu7/jJ0sXIwcEioCqx6XMySAMbkLnr3ixWEFtEQE3i0uIHzCD1 zAKzWSVOTT7LDJIQFvCS+HJ/LSOIzStgJfHlygSwBk4BS4lPPavA4kICK1klPs/1ArH5BcQk eq/8Z4K4yF6ibcsiqF5BiZMzn7CA2MwCOhInVh1jhrC1JZYtfM0MMUdR4vCSX+wQvUoSR7pn sEHYsRLL5r1incAoPAvJqFlIRs1CMmoBI/MqRpbi3HSjTYyQ+AvdwTij6aPeIUYmDsZDjBIc zEoivH7H3RKEeFMSK6tSi/Lji0pzUosPMUpzsCiJ8+495pogJJCeWJKanZpakFoEk2Xi4JRq YGo4krt5a/A7Rqbm48f4pC6VfHqaL1U7922z1yHtPa2Tdtl0W3a4VxT9MG1euvHkneWqgal9 z6UiOq+4/n4+r8Glc1Wt9M2EzIsZE27rVEwW5Qo8oKRmZH/D6MOxdx4i7c7Bm9U/RdTFCDn6 iWsv+lnutKL254Oobe1bH39TmF1vOOWuwf91TZtWHIw3bLHeVfEvxUGV4+mLlbc2C7pabdid UnKW+XWd/3Unn8f27TbBt7gu71/a++DQyeBPbfk1l1mf897/ducI63e+H+uyi9e1mV8MeBNT O8XoyrptjQfadCy4BJxaGc/bnPjhrbek1PHRm2K3dcemVQi0CZ5WSdgl4aTYG8Mom/0xZvpF HSWW4oxEQy3mouJEAEtHZ50uAwAA Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 5 Mar 2021 15:55:25 +0000 "Luck, Tony" wrote: > > From the walk, it seems we have got the virtual address, can we just send a SIGBUS with it? > > If the walk wins the race and the pte for the poisoned page is still valid, then yes. > > But we could have: > > CPU1 CPU2 > memory_failure sets poison > bit for struct page > > > rmap finds page in task > on CPU2 and sets PTE > to not-valid-poison > > memory_failure returns > early because struct page > already marked as poison > > walk page tables looking > for mapping - don't find it > > -Tony While I don't think there is a race condition, and if you really think the pfn with SIGBUS is not proper, I think following patch maybe one way. I copy your abandon code, and make a little modification, and just now it pass my simple test. And also this is a RFC version, only valid if you think the pfn with SIGBUS is not right. Thanks! >From a522ab8856e3a332a2318d57bb19f3c59594d462 Mon Sep 17 00:00:00 2001 From: Aili Yao Date: Wed, 10 Mar 2021 13:59:18 +0800 Subject: [PATCH] x86/mce: fix invalid SIGBUS address walk the current process pte and compare with the pfn; 1. only test for normal page and 2M hugetlb page; 2. 1G hugetlb and transparentHuge is not support currently; 3. May other fails is not recognized, This is a RFC version. --- arch/x86/kernel/cpu/mce/core.c | 83 ++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 80 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index db4afc5..65d7ef7 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -28,8 +28,12 @@ #include #include #include +#include +#include +#include #include #include +#include #include #include #include @@ -1235,6 +1239,81 @@ static void __mc_scan_banks(struct mce *m, struct pt_regs *regs, struct mce *fin /* mce_clear_state will clear *final, save locally for use later */ *m = *final; } +static int mc_pte_entry(pte_t *pte, unsigned long addr, unsigned long next, struct mm_walk *walk) +{ + u64 *buff = (u64 *)walk->private; + u64 pfn = buff[0]; + + if (!pte_present(*pte) && is_hwpoison_entry(pte_to_swp_entry(*pte))) + goto find; + else if (pte_pfn(*pte) == pfn) + goto find; + + return 0; +find: + buff[0] = addr; + buff[1] = PAGE_SHIFT; + return true; +} + +extern bool is_hugetlb_entry_hwpoisoned(pte_t pte); + +static int mc_hugetlb_range(pte_t *ptep, unsigned long hmask, + unsigned long addr, unsigned long end, + struct mm_walk *walk) +{ + u64 *buff = (u64 *)walk->private; + u64 pfn = buff[0]; + int shift = PMD_SHIFT; + pte_t pte = huge_ptep_get(ptep); + + if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) + goto find; + + if (pte_pfn(*ptep) == pfn) + goto find; + + return 0; +find: + buff[0] = addr; + buff[1] = shift; + return true; +} + +static struct mm_walk_ops walk = { + .pte_entry = mc_pte_entry, + .hugetlb_entry = mc_hugetlb_range +}; + +void mc_memory_failure_error(struct task_struct *p, unsigned long pfn) +{ + u64 buff[2] = {pfn, 0}; + struct page *page; + int ret = -1; + + page = pfn_to_page(pfn); + if (!page) + goto force_sigbus; + + if (is_zone_device_page(page)) + goto force_sigbus; + + mmap_read_lock(p->mm); + ret = walk_page_range(p->mm, 0, TASK_SIZE_MAX, &walk, (void *)buff); + mmap_read_unlock(p->mm); + + if (ret && buff[0]) { + pr_err("Memory error may not recovered: %#llx: Sending SIGBUS to %s:%d due to hardware memory corruption\n", + buff[0], p->comm, p->pid); + force_sig_mceerr(BUS_MCEERR_AR, (void __user *)buff[0], buff[1]); + } else { +force_sigbus: + pr_err("Memory error may not recovered, pfn: %#lx: Sending SIGBUS to %s:%d due to hardware memory corruption\n", + pfn, p->comm, p->pid); + force_sig_mceerr(BUS_MCEERR_AR, (void __user *)pfn, PAGE_SHIFT); + } + +} static void kill_me_now(struct callback_head *ch) { @@ -1259,9 +1338,7 @@ static void kill_me_maybe(struct callback_head *cb) } if (p->mce_vaddr != (void __user *)-1l) { - pr_err("Memory error may not recovered: %#lx: Sending SIGBUS to %s:%d due to hardware memory corruption\n", - p->mce_addr >> PAGE_SHIFT, p->comm, p->pid); - force_sig_mceerr(BUS_MCEERR_AR, p->mce_vaddr, PAGE_SHIFT); + mc_memory_failure_error(current, p->mce_addr >> PAGE_SHIFT); } else { pr_err("Memory error not recovered"); kill_me_now(cb); -- 1.8.3.1 -- Thanks! Aili Yao