From patchwork Tue Nov 27 16:25:35 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oscar Salvador X-Patchwork-Id: 10700795 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 417D113BB for ; Tue, 27 Nov 2018 16:26:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2EE6B2C012 for ; Tue, 27 Nov 2018 16:26:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 224422C0C2; Tue, 27 Nov 2018 16:26:09 +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=-1.1 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE,SUBJ_OBFU_PUNCT_FEW,SUBJ_OBFU_PUNCT_MANY autolearn=no version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 094ED2C012 for ; Tue, 27 Nov 2018 16:26:07 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 06F0C6B4900; Tue, 27 Nov 2018 11:26:07 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 01D4E6B4901; Tue, 27 Nov 2018 11:26:06 -0500 (EST) 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 E28296B4902; Tue, 27 Nov 2018 11:26:06 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by kanga.kvack.org (Postfix) with ESMTP id 8C81A6B4900 for ; Tue, 27 Nov 2018 11:26:06 -0500 (EST) Received: by mail-ed1-f71.google.com with SMTP id o21so7688213edq.4 for ; Tue, 27 Nov 2018 08:26:06 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:from:to:cc :subject:date:message-id; bh=F1Nr2zVB8EvcG8qb92zXU5I/lOCOVfhjZfaoDqEe3q8=; b=h5wMmI8QgvmAT5fgVsWSaIWguJs4JRottjdEo+/88OVPDJXeBkSrM4xqANBvjV23gG jRqoZBZ+oFLjYzJErUjpsbKCHGjXTIHrjqKjs5pwk93IoXBnBGLI6vk1lsCNIULiD1g+ 4TPUVcu0YIkaTsYShSgJMUE7C1xepid31+hDewDGIJSA3lbzeM35wF3r2JmD4lysMNhb g6hhlSWjlp1ZXnUVSiMWYVddJeaBvlcHRVWC/5oX6lY9VA8AfMfHeFvTMLLvV9UzXx7n fNhcs77FFNeGOkZZxWkOyJmHhQo4A6KKN5Np/f3YXVOPRzslPK9j8xLbrwIVx5DEQkHq uHaA== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of osalvador@suse.de designates 195.135.221.5 as permitted sender) smtp.mailfrom=osalvador@suse.de X-Gm-Message-State: AGRZ1gIPP0Z1UhEpCXsiNqPxAGlzc+jPkD8RhNL3HwEZkfcyZvh+Ghxa AT08PYfgcE4avmE9HAoYbQdEilQx4Ao2ODpIaXCH94xzpYGIk/Mso+CLQoxpP68wMWea56tfET8 XfOKyJzb02zI7sLNsSSLDRRz4jnBa11KKbMa7CZhpaNMRfBmb0MWV1Utq1CaOfuklyA== X-Received: by 2002:a17:906:6011:: with SMTP id o17-v6mr24235119ejj.237.1543335965959; Tue, 27 Nov 2018 08:26:05 -0800 (PST) X-Google-Smtp-Source: AJdET5egkTbZkoiWm976Lzh8hZ5ZGKQukFAoXqMCI02Rq0hl1ZFux70PdUBpvZiPkD+Iy2qQDUnC X-Received: by 2002:a17:906:6011:: with SMTP id o17-v6mr24235071ejj.237.1543335964707; Tue, 27 Nov 2018 08:26:04 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1543335964; cv=none; d=google.com; s=arc-20160816; b=nxyYiLHlaxdYvNN/Pgk95mQ/uUSYkqeGf6DgDIKwwZONqUuA1zOOFmWxafoqMFYr83 2hInOpUF64BkQpbm6QjIkCZhLj+Cga6RlSPtAzuCY1sCSu/Rz+ivJJjRnhOWBWudOVhs oAtITPqUNTJbV7ouuaRUMO6YPwvAmDAVZQBIzECux7D90G6Kpoi8OqZFtm73yTIqxqLa AN6aNRKNWyPJ8sIixUlAJ1v0kcrhq1ct0VZotRPh3wac+h4nGA3ZkHEYxiUyeOrXMNc9 hQOyJHfCSQfL5gcXWFZm5ljtpy+juY6iWiUInSoeHd/hvRmDlWpSR421sjhIHC0fW46t MXuw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=message-id:date:subject:cc:to:from; bh=F1Nr2zVB8EvcG8qb92zXU5I/lOCOVfhjZfaoDqEe3q8=; b=pqCG+nqJMUZqHjSoPe7BU6n7IbNlCsNDcYH/qC1/STOflYGkPovQqecO3+JaJIJVLM quFzurHcPdo60mOK0xI7leH4rLCKUwryevL+KlQNrO3xiETN+1v2vTB/YgA/cmo6NMDX 6X0hnTvVSBgYFwV1OP1IwL5wNpk8FDZeHYuGyQE9SAWEvc664p+St5S2B7yc1vCaGYGV Ws+yCxdj+4+01HX4hDS43myi8X2bsD2y31fa/nKqknnkV6T/hsJlt7BUsHsnaztk1KeU MoUVv35RoGIlxeVJ5EpPvdk8r4gvLDZOhc5K2oj8X7VZXu1MRytI2Agk4asyH121HlMn xuZA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of osalvador@suse.de designates 195.135.221.5 as permitted sender) smtp.mailfrom=osalvador@suse.de Received: from smtp.nue.novell.com (smtp.nue.novell.com. [195.135.221.5]) by mx.google.com with ESMTPS id k3-v6si27618ejr.219.2018.11.27.08.26.04 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 27 Nov 2018 08:26:04 -0800 (PST) Received-SPF: pass (google.com: domain of osalvador@suse.de designates 195.135.221.5 as permitted sender) client-ip=195.135.221.5; Authentication-Results: mx.google.com; spf=pass (google.com: domain of osalvador@suse.de designates 195.135.221.5 as permitted sender) smtp.mailfrom=osalvador@suse.de Received: from emea4-mta.ukb.novell.com ([10.120.13.87]) by smtp.nue.novell.com with ESMTP (TLS encrypted); Tue, 27 Nov 2018 17:26:03 +0100 Received: from d104.suse.de (nwb-a10-snat.microfocus.com [10.120.13.201]) by emea4-mta.ukb.novell.com with ESMTP (NOT encrypted); Tue, 27 Nov 2018 16:25:42 +0000 From: Oscar Salvador To: akpm@linux-foundation.org Cc: mhocko@suse.com, dan.j.williams@intel.com, pavel.tatashin@microsoft.com, jglisse@redhat.com, Jonathan.Cameron@huawei.com, rafael@kernel.org, david@redhat.com, linux-mm@kvack.org, Oscar Salvador , Oscar Salvador Subject: [PATCH v2 4/5] mm, memory-hotplug: Rework unregister_mem_sect_under_nodes Date: Tue, 27 Nov 2018 17:25:35 +0100 Message-Id: <20181127162535.15910-1-osalvador@suse.de> X-Mailer: git-send-email 2.13.6 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: X-Virus-Scanned: ClamAV using ClamSMTP From: Oscar Salvador This tries to address another issue about accessing unitiliazed pages. Jonathan reported a problem [1] where we can access steal pages in case we hot-remove memory without onlining it first. This time is in unregister_mem_sect_under_nodes. This function tries to get the nid from the pfn and then tries to remove the symlink between mem_blk <-> nid and vice versa. Since we already know the nid in remove_memory(), we can pass it down the chain to unregister_mem_sect_under_nodes. There we can just remove the symlinks without the need to look into the pages. This also allows us to cleanup unregister_mem_sect_under_nodes. [1] https://www.spinics.net/lists/linux-mm/msg161316.html Signed-off-by: Oscar Salvador Tested-by: Jonathan Cameron --- drivers/base/memory.c | 9 ++++----- drivers/base/node.c | 39 ++++++--------------------------------- include/linux/memory.h | 2 +- include/linux/node.h | 9 ++++----- mm/memory_hotplug.c | 2 +- 5 files changed, 16 insertions(+), 45 deletions(-) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 0e5985682642..3d8c65d84bea 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -744,8 +744,7 @@ unregister_memory(struct memory_block *memory) device_unregister(&memory->dev); } -static int remove_memory_section(unsigned long node_id, - struct mem_section *section, int phys_device) +static int remove_memory_section(unsigned long nid, struct mem_section *section) { struct memory_block *mem; @@ -759,7 +758,7 @@ static int remove_memory_section(unsigned long node_id, if (!mem) goto out_unlock; - unregister_mem_sect_under_nodes(mem, __section_nr(section)); + unregister_mem_sect_under_nodes(nid, mem); mem->section_count--; if (mem->section_count == 0) @@ -772,12 +771,12 @@ static int remove_memory_section(unsigned long node_id, return 0; } -int unregister_memory_section(struct mem_section *section) +int unregister_memory_section(int nid, struct mem_section *section) { if (!present_section(section)) return -EINVAL; - return remove_memory_section(0, section, 0); + return remove_memory_section(nid, section); } #endif /* CONFIG_MEMORY_HOTREMOVE */ diff --git a/drivers/base/node.c b/drivers/base/node.c index 86d6cd92ce3d..0858f7f3c7cd 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -453,40 +453,13 @@ int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg) return 0; } -/* unregister memory section under all nodes that it spans */ -int unregister_mem_sect_under_nodes(struct memory_block *mem_blk, - unsigned long phys_index) +/* Remove symlink between node <-> mem_blk */ +void unregister_mem_sect_under_nodes(int nid, struct memory_block *mem_blk) { - NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL); - unsigned long pfn, sect_start_pfn, sect_end_pfn; - - if (!mem_blk) { - NODEMASK_FREE(unlinked_nodes); - return -EFAULT; - } - if (!unlinked_nodes) - return -ENOMEM; - nodes_clear(*unlinked_nodes); - - sect_start_pfn = section_nr_to_pfn(phys_index); - sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1; - for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) { - int nid; - - nid = get_nid_for_pfn(pfn); - if (nid < 0) - continue; - if (!node_online(nid)) - continue; - if (node_test_and_set(nid, *unlinked_nodes)) - continue; - sysfs_remove_link(&node_devices[nid]->dev.kobj, - kobject_name(&mem_blk->dev.kobj)); - sysfs_remove_link(&mem_blk->dev.kobj, - kobject_name(&node_devices[nid]->dev.kobj)); - } - NODEMASK_FREE(unlinked_nodes); - return 0; + sysfs_remove_link(&node_devices[nid]->dev.kobj, + kobject_name(&mem_blk->dev.kobj)); + sysfs_remove_link(&mem_blk->dev.kobj, + kobject_name(&node_devices[nid]->dev.kobj)); } int link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_pfn) diff --git a/include/linux/memory.h b/include/linux/memory.h index a6ddefc60517..d75ec88ca09d 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -113,7 +113,7 @@ extern int register_memory_isolate_notifier(struct notifier_block *nb); extern void unregister_memory_isolate_notifier(struct notifier_block *nb); int hotplug_memory_register(int nid, struct mem_section *section); #ifdef CONFIG_MEMORY_HOTREMOVE -extern int unregister_memory_section(struct mem_section *); +extern int unregister_memory_section(int nid, struct mem_section *); #endif extern int memory_dev_init(void); extern int memory_notify(unsigned long val, void *v); diff --git a/include/linux/node.h b/include/linux/node.h index 257bb3d6d014..488c1333bb06 100644 --- a/include/linux/node.h +++ b/include/linux/node.h @@ -72,8 +72,8 @@ extern int register_cpu_under_node(unsigned int cpu, unsigned int nid); extern int unregister_cpu_under_node(unsigned int cpu, unsigned int nid); extern int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg); -extern int unregister_mem_sect_under_nodes(struct memory_block *mem_blk, - unsigned long phys_index); +extern void unregister_mem_sect_under_nodes(int nid, + struct memory_block *mem_blk); #ifdef CONFIG_HUGETLBFS extern void register_hugetlbfs_with_node(node_registration_func_t doregister, @@ -105,10 +105,9 @@ static inline int register_mem_sect_under_node(struct memory_block *mem_blk, { return 0; } -static inline int unregister_mem_sect_under_nodes(struct memory_block *mem_blk, - unsigned long phys_index) +static inline void unregister_mem_sect_under_nodes(int nid, + struct memory_block *mem_blk) { - return 0; } static inline void register_hugetlbfs_with_node(node_registration_func_t reg, diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 4fe42ccb0be4..49b91907e19e 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -544,7 +544,7 @@ static int __remove_section(int nid, struct mem_section *ms, if (!valid_section(ms)) return ret; - ret = unregister_memory_section(ms); + ret = unregister_memory_section(nid, ms); if (ret) return ret;