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=-2.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 80D55ECDFB8 for ; Mon, 23 Jul 2018 01:59:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 37D2A20854 for ; Mon, 23 Jul 2018 01:59:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linaro.org header.i=@linaro.org header.b="gnuUno+O" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 37D2A20854 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731287AbeGWC57 (ORCPT ); Sun, 22 Jul 2018 22:57:59 -0400 Received: from mail-pl0-f68.google.com ([209.85.160.68]:34512 "EHLO mail-pl0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731059AbeGWC57 (ORCPT ); Sun, 22 Jul 2018 22:57:59 -0400 Received: by mail-pl0-f68.google.com with SMTP id f6-v6so7543500plo.1 for ; Sun, 22 Jul 2018 18:59:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=VxevqCZhbKQ45BiJjQYFdciJrVc/rEp2DL/VeorXBAY=; b=gnuUno+OgQw9cCj7YXXmKBGdCpWCmY1R3+e52F2/cMxWD/ODZpv21K+jL+KbwNYIJ2 9s1Y8HIOctFjO17sUm3QXi7ZPLl/P3LKxeZErMVV6PRZyKRVEiPwzCk1lPUz0WejJJEU EFbWwLLpoLysdhjMvkClHiWG7B/9WtNjk6YTU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=VxevqCZhbKQ45BiJjQYFdciJrVc/rEp2DL/VeorXBAY=; b=BP5nasXwCo8//ER3ELcDqCD6HQfwCExrQ4oV0M2s3rrgvFFPzQHEKwIiY6/hnTopUF EWvu0XEpNe7WFLciDIKyZ3prZTAHYLa7zQ9xG11gsgFw5nkclWEdrMRA3EZF1cGlkbrG 8OYsb4FchFIvOJUMKLhR807Ygdressg6mXmJbQzv/l8sf2yX1uUlwzVRBgaGAFV83Q4A OcJVuh3/BXhw7j6rGHxuXbJ6QAAg1UG9mwzPl34/mT5zOZef556DRWSZ8rOYHzZ7Vekj 63jndd7BO7LjfC9PVMQiqnIrVdp2zJ9EgjvA/90w/1IK+LAEQ2qn/Zbr7b7DuqGCScgK dgZA== X-Gm-Message-State: AOUpUlH+ahHFAh8hrk7RTXnqKwEZRv8ptl39nG1Gvwi0ERpJ689QBe6K vN+MYtY9etr10CEzPT+nAoHR7A== X-Google-Smtp-Source: AAOMgpcuwqefyGHc5fFVOmJlZjG5COrX0ofFxjg9KekhfT9Q0Xzkev7CVic4pZjlaKNBaKPwDPNY4A== X-Received: by 2002:a17:902:8645:: with SMTP id y5-v6mr10978442plt.334.1532311152593; Sun, 22 Jul 2018 18:59:12 -0700 (PDT) Received: from linaro.org ([121.95.100.191]) by smtp.googlemail.com with ESMTPSA id 85-v6sm20185621pgd.81.2018.07.22.18.59.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 22 Jul 2018 18:59:12 -0700 (PDT) From: AKASHI Takahiro To: catalin.marinas@arm.com, will.deacon@arm.com, rjw@rjwysocki.net, lenb@kernel.org, ard.biesheuvel@linaro.org Cc: tbaicar@codeaurora.org, bhsharma@redhat.com, dyoung@redhat.com, james.morse@arm.com, mark.rutland@arm.com, al.stone@linaro.org, graeme.gregory@linaro.org, hanjun.guo@linaro.org, lorenzo.pieralisi@arm.com, sudeep.holla@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org Subject: [PATCH v4 1/5] arm64: export memblock_reserve()d regions via /proc/iomem Date: Mon, 23 Jul 2018 10:57:28 +0900 Message-Id: <20180723015732.24252-2-takahiro.akashi@linaro.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180723015732.24252-1-takahiro.akashi@linaro.org> References: <20180723015732.24252-1-takahiro.akashi@linaro.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: James Morse There has been some confusion around what is necessary to prevent kexec overwriting important memory regions. memblock: reserve, or nomap? Only memblock nomap regions are reported via /proc/iomem, kexec's user-space doesn't know about memblock_reserve()d regions. Until commit f56ab9a5b73ca ("efi/arm: Don't mark ACPI reclaim memory as MEMBLOCK_NOMAP") the ACPI tables were nomap, now they are reserved and thus possible for kexec to overwrite with the new kernel or initrd. But this was always broken, as the UEFI memory map is also reserved and not marked as nomap. Exporting both nomap and reserved memblock types is a nuisance as they live in different memblock structures which we can't walk at the same time. Take a second walk over memblock.reserved and add new 'reserved' subnodes for the memblock_reserved() regions that aren't already described by the existing code. (e.g. Kernel Code) We use reserve_region_with_split() to find the gaps in existing named regions. This handles the gap between 'kernel code' and 'kernel data' which is memblock_reserve()d, but already partially described by request_standard_resources(). e.g.: | 80000000-dfffffff : System RAM | 80080000-80ffffff : Kernel code | 81000000-8158ffff : reserved | 81590000-8237efff : Kernel data | a0000000-dfffffff : Crash kernel | e00f0000-f949ffff : System RAM reserve_region_with_split needs kzalloc() which isn't available when request_standard_resources() is called, use an initcall. Reported-by: Bhupesh Sharma Reported-by: Tyler Baicar Suggested-by: Akashi Takahiro Signed-off-by: James Morse Fixes: d28f6df1305a ("arm64/kexec: Add core kexec support") Reviewed-by: Ard Biesheuvel CC: Mark Rutland --- arch/arm64/kernel/setup.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 30ad2f085d1f..5b4fac434c84 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -241,6 +241,44 @@ static void __init request_standard_resources(void) } } +static int __init reserve_memblock_reserved_regions(void) +{ + phys_addr_t start, end, roundup_end = 0; + struct resource *mem, *res; + u64 i; + + for_each_reserved_mem_region(i, &start, &end) { + if (end <= roundup_end) + continue; /* done already */ + + start = __pfn_to_phys(PFN_DOWN(start)); + end = __pfn_to_phys(PFN_UP(end)) - 1; + roundup_end = end; + + res = kzalloc(sizeof(*res), GFP_ATOMIC); + if (WARN_ON(!res)) + return -ENOMEM; + res->start = start; + res->end = end; + res->name = "reserved"; + res->flags = IORESOURCE_MEM; + + mem = request_resource_conflict(&iomem_resource, res); + /* + * We expected memblock_reserve() regions to conflict with + * memory created by request_standard_resources(). + */ + if (WARN_ON_ONCE(!mem)) + continue; + kfree(res); + + reserve_region_with_split(mem, start, end, "reserved"); + } + + return 0; +} +arch_initcall(reserve_memblock_reserved_regions); + u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID }; void __init setup_arch(char **cmdline_p) -- 2.18.0