From patchwork Thu Mar 26 18:07:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 11460725 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 CF59A6CA for ; Thu, 26 Mar 2020 18:08:37 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A68BE20722 for ; Thu, 26 Mar 2020 18:08:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A68BE20722 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C3C796B0037; Thu, 26 Mar 2020 14:08:36 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id BF4E46B006C; Thu, 26 Mar 2020 14:08:36 -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 B037A6B006E; Thu, 26 Mar 2020 14:08:36 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0033.hostedemail.com [216.40.44.33]) by kanga.kvack.org (Postfix) with ESMTP id 9996B6B0037 for ; Thu, 26 Mar 2020 14:08:36 -0400 (EDT) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id CD55F8248D7C for ; Thu, 26 Mar 2020 18:08:36 +0000 (UTC) X-FDA: 76638298632.27.song19_10f408fc08f00 X-Spam-Summary: 2,0,0,b6b048dcbda4c814,d41d8cd98f00b204,james.morse@arm.com,,RULES_HIT:41:355:379:541:800:960:973:988:989:1260:1261:1311:1314:1345:1359:1437:1515:1534:1541:1711:1730:1747:1777:1792:2198:2199:2393:2559:2562:3138:3139:3140:3141:3142:3352:3865:3866:3867:3870:3871:3874:4250:4321:5007:6261:7903:8634:10004:11026:11232:11473:11657:11658:11914:12043:12296:12297:12438:12517:12519:12555:12895:12986:13069:13161:13229:13311:13357:13894:14096:14181:14384:14394:14721:21080:21451:21627:21795:30025:30029:30054:30070,0,RBL:217.140.110.172:@arm.com:.lbl8.mailshell.net-62.2.0.100 64.100.201.201,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:1,LUA_SUMMARY:none X-HE-Tag: song19_10f408fc08f00 X-Filterd-Recvd-Size: 2788 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf02.hostedemail.com (Postfix) with ESMTP for ; Thu, 26 Mar 2020 18:08:36 +0000 (UTC) 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 142A71063; Thu, 26 Mar 2020 11:08:35 -0700 (PDT) Received: from melchizedek.cambridge.arm.com (melchizedek.cambridge.arm.com [10.1.196.50]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B2A023F71E; Thu, 26 Mar 2020 11:08:33 -0700 (PDT) From: James Morse To: kexec@lists.infradead.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org Cc: Eric Biederman , Andrew Morton , Catalin Marinas , Will Deacon , Anshuman Khandual , Bhupesh Sharma , James Morse Subject: [PATCH 3/3] arm64: memory: Give hotplug memory a different resource name Date: Thu, 26 Mar 2020 18:07:30 +0000 Message-Id: <20200326180730.4754-4-james.morse@arm.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20200326180730.4754-1-james.morse@arm.com> References: <20200326180730.4754-1-james.morse@arm.com> MIME-Version: 1.0 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: If kexec chooses to place the kernel in a memory region that was added after boot, we fail to boot as the kernel is running from a location that is not described as memory by the UEFI memory map or the original DT. To prevent unaware user-space kexec from doing this accidentally, give these regions a different name. Signed-off-by: James Morse --- This is a change in behaviour as seen by user-space, because memory hot-add has already been merged. arch/arm64/include/asm/memory.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 2be67b232499..ef1686518469 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -166,6 +166,17 @@ #define IOREMAP_MAX_ORDER (PMD_SHIFT) #endif +/* + * Memory hotplug allows new regions of 'System RAM' to be added to the system. + * These aren't described as memory by the UEFI memory map, or DT memory node. + * If we kexec from one of these regions, the new kernel boots from a location + * that isn't described as RAM. + * + * Give these resources a different name, so unaware kexec doesn't do this by + * accident. + */ +#define MEMORY_HOTPLUG_RES_NAME "System RAM (hotplug)" + #ifndef __ASSEMBLY__ extern u64 vabits_actual; #define PAGE_END (_PAGE_END(vabits_actual))