From patchwork Thu Jul 25 22:01:40 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jane Chu X-Patchwork-Id: 11059711 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 804921580 for ; Thu, 25 Jul 2019 22:01:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6FCE028A34 for ; Thu, 25 Jul 2019 22:01:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 63FBC28A74; Thu, 25 Jul 2019 22:01:54 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id EB14428A34 for ; Thu, 25 Jul 2019 22:01:53 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 22C5D2194EB76; Thu, 25 Jul 2019 15:04:20 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=156.151.31.86; helo=userp2130.oracle.com; envelope-from=jane.chu@oracle.com; receiver=linux-nvdimm@lists.01.org Received: from userp2130.oracle.com (userp2130.oracle.com [156.151.31.86]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id C9199212E13A2 for ; Thu, 25 Jul 2019 15:04:17 -0700 (PDT) Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x6PLnjVN047526; Thu, 25 Jul 2019 22:01:47 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2018-07-02; bh=Wehduxv3rRQK2E7/irEvOjIfxwzfa7zL656bjo3lVcY=; b=GhtfdZvuNUNRbc8Vg+Twnr3rIF2aJVHyoy9A1Nkp5MOGKkueLofl0az5WE7GrW2OW6k7 nqD6hyY3lWV1dtvvkIG/Nyj94uSjW18m7qYuiFXwuF2/C2YIZro4VLo1AEIsuUpXs0ZG SaFGRAjp2/Qc24wBHqHbFX5Zm519HSKRzXOjpBg+d4Jbr3GegG8rZi75vG0F64us7A+d ftKYlo0nYjKzHySQ5oo/qU1x9OcJteprFl7AJEl1xmfqMo0tibm/eKyLlUfPLRhPHT/T c2Wla83gmr+2lPRukmodPR9FXb0/KOGHah41gvewrIsrvFZPVd6Rfh3FP1jAlN7/6lTL EQ== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2130.oracle.com with ESMTP id 2tx61c6r9f-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 25 Jul 2019 22:01:47 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x6PLqMsG020509; Thu, 25 Jul 2019 22:01:46 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserp3020.oracle.com with ESMTP id 2tyd3nw50n-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 25 Jul 2019 22:01:46 +0000 Received: from abhmp0010.oracle.com (abhmp0010.oracle.com [141.146.116.16]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x6PM1jwF028641; Thu, 25 Jul 2019 22:01:45 GMT Received: from brm-x32-03.us.oracle.com (/10.80.150.35) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 25 Jul 2019 15:01:45 -0700 From: Jane Chu To: n-horiguchi@ah.jp.nec.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 1/2] mm/memory-failure.c clean up around tk pre-allocation Date: Thu, 25 Jul 2019 16:01:40 -0600 Message-Id: <1564092101-3865-2-git-send-email-jane.chu@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1564092101-3865-1-git-send-email-jane.chu@oracle.com> References: <1564092101-3865-1-git-send-email-jane.chu@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9329 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=930 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1907250263 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9329 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=983 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1907250263 X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-nvdimm@lists.01.org MIME-Version: 1.0 Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP add_to_kill() expects the first 'tk' to be pre-allocated, it makes subsequent allocations on need basis, this makes the code a bit difficult to read. Move all the allocation internal to add_to_kill() and drop the **tk argument. Signed-off-by: Jane Chu Acked-by: Naoya Horiguchi --- mm/memory-failure.c | 40 +++++++++++++--------------------------- 1 file changed, 13 insertions(+), 27 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index d9cc660..51d5b20 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -304,25 +304,19 @@ static unsigned long dev_pagemap_mapping_shift(struct page *page, /* * Schedule a process for later kill. * Uses GFP_ATOMIC allocations to avoid potential recursions in the VM. - * TBD would GFP_NOIO be enough? */ static void add_to_kill(struct task_struct *tsk, struct page *p, struct vm_area_struct *vma, - struct list_head *to_kill, - struct to_kill **tkc) + struct list_head *to_kill) { struct to_kill *tk; - if (*tkc) { - tk = *tkc; - *tkc = NULL; - } else { - tk = kmalloc(sizeof(struct to_kill), GFP_ATOMIC); - if (!tk) { - pr_err("Memory failure: Out of memory while machine check handling\n"); - return; - } + tk = kmalloc(sizeof(struct to_kill), GFP_ATOMIC); + if (!tk) { + pr_err("Memory failure: Out of memory while machine check handling\n"); + return; } + tk->addr = page_address_in_vma(p, vma); tk->addr_valid = 1; if (is_zone_device_page(p)) @@ -341,6 +335,7 @@ static void add_to_kill(struct task_struct *tsk, struct page *p, page_to_pfn(p), tsk->comm); tk->addr_valid = 0; } + get_task_struct(tsk); tk->tsk = tsk; list_add_tail(&tk->nd, to_kill); @@ -432,7 +427,7 @@ static struct task_struct *task_early_kill(struct task_struct *tsk, * Collect processes when the error hit an anonymous page. */ static void collect_procs_anon(struct page *page, struct list_head *to_kill, - struct to_kill **tkc, int force_early) + int force_early) { struct vm_area_struct *vma; struct task_struct *tsk; @@ -457,7 +452,7 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill, if (!page_mapped_in_vma(page, vma)) continue; if (vma->vm_mm == t->mm) - add_to_kill(t, page, vma, to_kill, tkc); + add_to_kill(t, page, vma, to_kill); } } read_unlock(&tasklist_lock); @@ -468,7 +463,7 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill, * Collect processes when the error hit a file mapped page. */ static void collect_procs_file(struct page *page, struct list_head *to_kill, - struct to_kill **tkc, int force_early) + int force_early) { struct vm_area_struct *vma; struct task_struct *tsk; @@ -492,7 +487,7 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill, * to be informed of all such data corruptions. */ if (vma->vm_mm == t->mm) - add_to_kill(t, page, vma, to_kill, tkc); + add_to_kill(t, page, vma, to_kill); } } read_unlock(&tasklist_lock); @@ -501,26 +496,17 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill, /* * Collect the processes who have the corrupted page mapped to kill. - * This is done in two steps for locking reasons. - * First preallocate one tokill structure outside the spin locks, - * so that we can kill at least one process reasonably reliable. */ static void collect_procs(struct page *page, struct list_head *tokill, int force_early) { - struct to_kill *tk; - if (!page->mapping) return; - tk = kmalloc(sizeof(struct to_kill), GFP_NOIO); - if (!tk) - return; if (PageAnon(page)) - collect_procs_anon(page, tokill, &tk, force_early); + collect_procs_anon(page, tokill, force_early); else - collect_procs_file(page, tokill, &tk, force_early); - kfree(tk); + collect_procs_file(page, tokill, force_early); } static const char *action_name[] = { From patchwork Thu Jul 25 22:01:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jane Chu X-Patchwork-Id: 11059713 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 754061580 for ; Thu, 25 Jul 2019 22:01:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6397C28A34 for ; Thu, 25 Jul 2019 22:01:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 57BCD28A35; Thu, 25 Jul 2019 22:01:55 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id F395B28A37 for ; 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Thu, 25 Jul 2019 22:01:47 +0000 Received: from abhmp0010.oracle.com (abhmp0010.oracle.com [141.146.116.16]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x6PM1k4u021541; Thu, 25 Jul 2019 22:01:46 GMT Received: from brm-x32-03.us.oracle.com (/10.80.150.35) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 25 Jul 2019 15:01:46 -0700 From: Jane Chu To: n-horiguchi@ah.jp.nec.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 2/2] mm/memory-failure: Poison read receives SIGKILL instead of SIGBUS if mmaped more than once Date: Thu, 25 Jul 2019 16:01:41 -0600 Message-Id: <1564092101-3865-3-git-send-email-jane.chu@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1564092101-3865-1-git-send-email-jane.chu@oracle.com> References: <1564092101-3865-1-git-send-email-jane.chu@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9329 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1907250263 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9329 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1907250263 X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-nvdimm@lists.01.org MIME-Version: 1.0 Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP Mmap /dev/dax more than once, then read the poison location using address from one of the mappings. The other mappings due to not having the page mapped in will cause SIGKILLs delivered to the process. SIGKILL succeeds over SIGBUS, so user process looses the opportunity to handle the UE. Although one may add MAP_POPULATE to mmap(2) to work around the issue, MAP_POPULATE makes mapping 128GB of pmem several magnitudes slower, so isn't always an option. Details - ndctl inject-error --block=10 --count=1 namespace6.0 ./read_poison -x dax6.0 -o 5120 -m 2 mmaped address 0x7f5bb6600000 mmaped address 0x7f3cf3600000 doing local read at address 0x7f3cf3601400 Killed Console messages in instrumented kernel - mce: Uncorrected hardware memory error in user-access at edbe201400 Memory failure: tk->addr = 7f5bb6601000 Memory failure: address edbe201: call dev_pagemap_mapping_shift dev_pagemap_mapping_shift: page edbe201: no PUD Memory failure: tk->size_shift == 0 Memory failure: Unable to find user space address edbe201 in read_poison Memory failure: tk->addr = 7f3cf3601000 Memory failure: address edbe201: call dev_pagemap_mapping_shift Memory failure: tk->size_shift = 21 Memory failure: 0xedbe201: forcibly killing read_poison:22434 because of failure to unmap corrupted page => to deliver SIGKILL Memory failure: 0xedbe201: Killing read_poison:22434 due to hardware memory corruption => to deliver SIGBUS Signed-off-by: Jane Chu Suggested-by: Naoya Horiguchi Acked-by: Naoya Horiguchi Acked-by: Naoya Horiguchi --- mm/memory-failure.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 51d5b20..f668c88 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -199,7 +199,6 @@ struct to_kill { struct task_struct *tsk; unsigned long addr; short size_shift; - char addr_valid; }; /* @@ -318,22 +317,27 @@ static void add_to_kill(struct task_struct *tsk, struct page *p, } tk->addr = page_address_in_vma(p, vma); - tk->addr_valid = 1; if (is_zone_device_page(p)) tk->size_shift = dev_pagemap_mapping_shift(p, vma); else tk->size_shift = compound_order(compound_head(p)) + PAGE_SHIFT; /* - * In theory we don't have to kill when the page was - * munmaped. But it could be also a mremap. Since that's - * likely very rare kill anyways just out of paranoia, but use - * a SIGKILL because the error is not contained anymore. + * Send SIGKILL if "tk->addr == -EFAULT". Also, as + * "tk->size_shift" is always non-zero for !is_zone_device_page(), + * so "tk->size_shift == 0" effectively checks no mapping on + * ZONE_DEVICE. Indeed, when a devdax page is mmapped N times + * to a process' address space, it's possible not all N VMAs + * contain mappings for the page, but at least one VMA does. + * Only deliver SIGBUS with payload derived from the VMA that + * has a mapping for the page. */ - if (tk->addr == -EFAULT || tk->size_shift == 0) { + if (tk->addr == -EFAULT) { pr_info("Memory failure: Unable to find user space address %lx in %s\n", page_to_pfn(p), tsk->comm); - tk->addr_valid = 0; + } else if (tk->size_shift == 0) { + kfree(tk); + return; } get_task_struct(tsk); @@ -361,7 +365,7 @@ static void kill_procs(struct list_head *to_kill, int forcekill, bool fail, * make sure the process doesn't catch the * signal and then access the memory. Just kill it. */ - if (fail || tk->addr_valid == 0) { + if (fail || tk->addr == -EFAULT) { pr_err("Memory failure: %#lx: forcibly killing %s:%d because of failure to unmap corrupted page\n", pfn, tk->tsk->comm, tk->tsk->pid); do_send_sig_info(SIGKILL, SEND_SIG_PRIV,