From patchwork Fri Jul 17 17:59:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 11671037 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 848DB60D for ; Fri, 17 Jul 2020 18:02:19 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5CAE1206F4 for ; Fri, 17 Jul 2020 18:02:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5CAE1206F4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 966566B0006; Fri, 17 Jul 2020 14:02:18 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 8F0B26B0027; Fri, 17 Jul 2020 14:02:18 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7DDDD6B007B; Fri, 17 Jul 2020 14:02:18 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0241.hostedemail.com [216.40.44.241]) by kanga.kvack.org (Postfix) with ESMTP id 63E9C6B0006 for ; Fri, 17 Jul 2020 14:02:18 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 21637DE05 for ; Fri, 17 Jul 2020 18:02:18 +0000 (UTC) X-FDA: 77048337156.16.toes18_47151ba26f0c Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin16.hostedemail.com (Postfix) with ESMTP id CE35B100E4AF0 for ; Fri, 17 Jul 2020 18:02:17 +0000 (UTC) X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,jonathan.cameron@huawei.com,,RULES_HIT:30054:30070:30080:30090,0,RBL:185.176.76.210:@huawei.com:.lbl8.mailshell.net-62.18.15.100 64.95.201.95;04yroacae4gkgwpja9qssfro15p9eoc3mrhtdgcx59s74puspjhs8hsish4tqi1.i64doj8j78a3xxtf7fyamcfjfswn4ux1mz7ncopuus7epz4f9cptmcaqhpxdmyz.w-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:24,LUA_SUMMARY:none X-HE-Tag: toes18_47151ba26f0c X-Filterd-Recvd-Size: 4016 Received: from huawei.com (lhrrgout.huawei.com [185.176.76.210]) by imf48.hostedemail.com (Postfix) with ESMTP for ; Fri, 17 Jul 2020 18:02:17 +0000 (UTC) Received: from lhreml710-chm.china.huawei.com (unknown [172.18.7.106]) by Forcepoint Email with ESMTP id 102AE61B9167C6AA9A63; Fri, 17 Jul 2020 19:02:16 +0100 (IST) Received: from lhrphicprd00229.huawei.com (10.123.41.22) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.1913.5; Fri, 17 Jul 2020 19:02:15 +0100 From: Jonathan Cameron To: , , , CC: Lorenzo Pieralisi , Bjorn Helgaas , , , Ingo Molnar , , Tony Luck , Fenghua Yu , Thomas Gleixner , , Dan Williams , Song Bao Hua , Jonathan Cameron Subject: [PATCH v2 3/6] ACPI: Remove side effect of partly creating a node in acpi_map_pxm_to_online_node Date: Sat, 18 Jul 2020 01:59:56 +0800 Message-ID: <20200717175959.899775-4-Jonathan.Cameron@huawei.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20200717175959.899775-1-Jonathan.Cameron@huawei.com> References: <20200717175959.899775-1-Jonathan.Cameron@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.123.41.22] X-ClientProxiedBy: lhreml706-chm.china.huawei.com (10.201.108.55) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected X-Rspamd-Queue-Id: CE35B100E4AF0 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Whilst this function will only return an online node, it can have the side effect of partially creating a new node. The existing comments suggest this is intentional, but the usecases of this function are related to NFIT and HMAT parsing, neither of which should be able to define new nodes. One route by which the existing behaviour would cause a crash is to have a _PXM entry in ACPI DSDT attempt to place a device within this partly created proximity domain. A subsequent call to devm_kzalloc or similar would result in an attempt to allocate memory on a node for which zone lists have not been set up and a null pointer dereference. We prevent such cases by switching to pxm_to_node() within acpi_map_pxm_to_online_node which cannot cause a new node to be partly created. If one would previously have been created we now return NO_NUMA_NODE. Documentation updated to reflect this change. We may want to think about renaming acpi_map_pxm_to_online_node to pxm_to_online_node to reflect this change. Signed-off-by: Jonathan Cameron --- include/linux/acpi.h | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/include/linux/acpi.h b/include/linux/acpi.h index d661cd0ee64d..b541a0b444fd 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -430,13 +430,12 @@ int acpi_get_node(acpi_handle handle); * ACPI device drivers, which are called after the NUMA initialization has * completed in the kernel, can call this interface to obtain their device * NUMA topology from ACPI tables. Such drivers do not have to deal with - * offline nodes. A node may be offline when a device proximity ID is - * unique, SRAT memory entry does not exist, or NUMA is disabled, ex. - * "numa=off" on x86. + * offline nodes. A node may be offline when SRAT memory entry does not exist, + * or NUMA is disabled, ex. "numa=off" on x86. */ static inline int acpi_map_pxm_to_online_node(int pxm) { - int node = acpi_map_pxm_to_node(pxm); + int node = pxm_to_node(pxm); return numa_map_to_online_node(node); }