From patchwork Mon Jan 25 02:58:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anshuman Khandual X-Patchwork-Id: 12042865 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=-17.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 E3FC9C433E6 for ; Mon, 25 Jan 2021 03:00:56 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9BC0722472 for ; Mon, 25 Jan 2021 03:00:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9BC0722472 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:MIME-Version:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:References:In-Reply-To:Message-Id:Date:Subject:To: From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=EInlofRxaFgjj0QOP51Q3IRe5Ps+rTBX7YRTiNy3AcY=; b=A/LAVv6uU6ZSoXeTbMzNgvkRof rddxaoYmqFmbBcY1/qJRSlLVwnXWhr4YGONwfdhhHB4rAIWeFWZCSKoyVwKW5CmvS60mL4xXgbmdw Ns50rhIKTgrhKQnwSTeBe4Kn/GSAUdaLOPGdFIPVku1JN7g1tfd25NV3LgAWeUeZwBKkmjd9CLwuZ QYoUJY7g1TIpOX8FI6UcSJItA+8G5TxAayi+cDlxqDvIz3z1W/4ZyA6yK0VL9ajGWwmGki/TodFBW UrHhrB+5IxrMNqlpWPl5WpOP8TBwQmxVH2Kz9KdUefGobiiuHE5luxvWY0LNmMPImZRdKuYdTWhwk XTQWHoYA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l3s5i-0004oO-05; Mon, 25 Jan 2021 02:58:58 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l3s5c-0004nP-6O for linux-arm-kernel@lists.infradead.org; Mon, 25 Jan 2021 02:58:53 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 30D5C139F; Sun, 24 Jan 2021 18:58:50 -0800 (PST) Received: from p8cg001049571a15.arm.com (unknown [10.163.91.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 8CBEA3F66E; Sun, 24 Jan 2021 18:58:45 -0800 (PST) From: Anshuman Khandual To: linux-mm@kvack.org, akpm@linux-foundation.org, hca@linux.ibm.com, catalin.marinas@arm.com Subject: [PATCH V4 1/4] mm/memory_hotplug: Prevalidate the address range being added with platform Date: Mon, 25 Jan 2021 08:28:49 +0530 Message-Id: <1611543532-18698-2-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1611543532-18698-1-git-send-email-anshuman.khandual@arm.com> References: <1611543532-18698-1-git-send-email-anshuman.khandual@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210124_215852_378912_FEE061C9 X-CRM114-Status: GOOD ( 24.33 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , linux-s390@vger.kernel.org, Vasily Gorbik , Anshuman Khandual , David Hildenbrand , linux-kernel@vger.kernel.org, Will Deacon , Ard Biesheuvel , linux-arm-kernel@lists.infradead.org, Oscar Salvador MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org This introduces mhp_range_allowed() which can be called in various memory hotplug paths to prevalidate the address range which is being added, with the platform. Then mhp_range_allowed() calls mhp_get_pluggable_range() which provides applicable address range depending on whether linear mapping is required or not. For ranges that require linear mapping, it calls a new arch callback arch_get_mappable_range() which the platform can override. So the new callback, in turn provides the platform an opportunity to configure acceptable memory hotplug address ranges in case there are constraints. This mechanism will help prevent platform specific errors deep down during hotplug calls. This drops now redundant check_hotplug_memory_addressable() check in __add_pages() but instead adds a VM_BUG_ON() check which would ensure that the range has been validated with mhp_range_allowed() earlier in the call chain. Besides mhp_get_pluggable_range() also can be used by potential memory hotplug callers to avail the allowed physical range which would go through on a given platform. This does not really add any new range check in generic memory hotplug but instead compensates for lost checks in arch_add_memory() where applicable and check_hotplug_memory_addressable(), with unified mhp_range_allowed(). Cc: David Hildenbrand Cc: Andrew Morton Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Oscar Salvador Suggested-by: David Hildenbrand Signed-off-by: Anshuman Khandual Reviewed-by: David Hildenbrand --- include/linux/memory_hotplug.h | 10 +++++ mm/memory_hotplug.c | 78 +++++++++++++++++++++++++--------- mm/memremap.c | 6 ++- 3 files changed, 74 insertions(+), 20 deletions(-) diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 15acce5ab106..e4c80561e519 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -70,6 +70,9 @@ typedef int __bitwise mhp_t; */ #define MEMHP_MERGE_RESOURCE ((__force mhp_t)BIT(0)) +bool mhp_range_allowed(u64 start, u64 size, bool need_mapping); +struct range mhp_get_pluggable_range(bool need_mapping); + /* * Extended parameters for memory hotplug: * altmap: alternative allocator for memmap array (optional) @@ -281,6 +284,13 @@ static inline bool movable_node_is_enabled(void) } #endif /* ! CONFIG_MEMORY_HOTPLUG */ +/* + * Keep this declaration outside CONFIG_MEMORY_HOTPLUG as some + * platforms might override and use arch_get_mappable_range() + * for internal non memory hotplug purposes. + */ +struct range arch_get_mappable_range(void); + #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT) /* * pgdat resizing functions diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index f9d57b9be8c7..fb734a865807 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -107,6 +107,9 @@ static struct resource *register_memory_resource(u64 start, u64 size, if (strcmp(resource_name, "System RAM")) flags |= IORESOURCE_SYSRAM_DRIVER_MANAGED; + if (!mhp_range_allowed(start, size, true)) + return ERR_PTR(-E2BIG); + /* * Make sure value parsed from 'mem=' only restricts memory adding * while booting, so that memory hotplug won't be impacted. Please @@ -284,22 +287,6 @@ static int check_pfn_span(unsigned long pfn, unsigned long nr_pages, return 0; } -static int check_hotplug_memory_addressable(unsigned long pfn, - unsigned long nr_pages) -{ - const u64 max_addr = PFN_PHYS(pfn + nr_pages) - 1; - - if (max_addr >> MAX_PHYSMEM_BITS) { - const u64 max_allowed = (1ull << (MAX_PHYSMEM_BITS + 1)) - 1; - WARN(1, - "Hotplugged memory exceeds maximum addressable address, range=%#llx-%#llx, maximum=%#llx\n", - (u64)PFN_PHYS(pfn), max_addr, max_allowed); - return -E2BIG; - } - - return 0; -} - /* * Reasonably generic function for adding memory. It is * expected that archs that support memory hotplug will @@ -317,9 +304,7 @@ int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages, if (WARN_ON_ONCE(!params->pgprot.pgprot)) return -EINVAL; - err = check_hotplug_memory_addressable(pfn, nr_pages); - if (err) - return err; + VM_BUG_ON(!mhp_range_allowed(PFN_PHYS(pfn), nr_pages * PAGE_SIZE, false)); if (altmap) { /* @@ -1180,6 +1165,61 @@ int add_memory_driver_managed(int nid, u64 start, u64 size, } EXPORT_SYMBOL_GPL(add_memory_driver_managed); +/* + * Platforms should define arch_get_mappable_range() that provides + * maximum possible addressable physical memory range for which the + * linear mapping could be created. The platform returned address + * range must adhere to these following semantics. + * + * - range.start <= range.end + * - Range includes both end points [range.start..range.end] + * + * There is also a fallback definition provided here, allowing the + * entire possible physical address range in case any platform does + * not define arch_get_mappable_range(). + */ +struct range __weak arch_get_mappable_range(void) +{ + struct range mhp_range = { + .start = 0UL, + .end = -1ULL, + }; + return mhp_range; +} + +struct range mhp_get_pluggable_range(bool need_mapping) +{ + const u64 max_phys = (1ULL << MAX_PHYSMEM_BITS) - 1; + struct range mhp_range; + + if (need_mapping) { + mhp_range = arch_get_mappable_range(); + if (mhp_range.start > max_phys) { + mhp_range.start = 0; + mhp_range.end = 0; + } + mhp_range.end = min_t(u64, mhp_range.end, max_phys); + } else { + mhp_range.start = 0; + mhp_range.end = max_phys; + } + return mhp_range; +} +EXPORT_SYMBOL_GPL(mhp_get_pluggable_range); + +bool mhp_range_allowed(u64 start, u64 size, bool need_mapping) +{ + struct range mhp_range = mhp_get_pluggable_range(need_mapping); + u64 end = start + size; + + if (start < end && start >= mhp_range.start && (end - 1) <= mhp_range.end) + return true; + + pr_warn("Hotplug memory [%#llx-%#llx] exceeds maximum addressable range [%#llx-%#llx]\n", + start, end, mhp_range.start, mhp_range.end); + return false; +} + #ifdef CONFIG_MEMORY_HOTREMOVE /* * Confirm all pages in a range [start, end) belong to the same zone (skipping diff --git a/mm/memremap.c b/mm/memremap.c index 16b2fb482da1..fcc5679e3fab 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -185,6 +185,7 @@ static void dev_pagemap_percpu_release(struct percpu_ref *ref) static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params, int range_id, int nid) { + const bool is_private = pgmap->type == MEMORY_DEVICE_PRIVATE; struct range *range = &pgmap->ranges[range_id]; struct dev_pagemap *conflict_pgmap; int error, is_ram; @@ -230,6 +231,9 @@ static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params, if (error) goto err_pfn_remap; + if (!mhp_range_allowed(range->start, range_len(range), !is_private)) + goto err_pfn_remap; + mem_hotplug_begin(); /* @@ -243,7 +247,7 @@ static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params, * the CPU, we do want the linear mapping and thus use * arch_add_memory(). */ - if (pgmap->type == MEMORY_DEVICE_PRIVATE) { + if (is_private) { error = add_pages(nid, PHYS_PFN(range->start), PHYS_PFN(range_len(range)), params); } else {