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=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 DBFB7C07E96 for ; Tue, 13 Jul 2021 18:43:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B9C4E61369 for ; Tue, 13 Jul 2021 18:43:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234061AbhGMSqk (ORCPT ); Tue, 13 Jul 2021 14:46:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:36514 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229478AbhGMSqj (ORCPT ); Tue, 13 Jul 2021 14:46:39 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 453ED6127C; Tue, 13 Jul 2021 18:43:49 +0000 (UTC) Received: from sofa.misterjones.org ([185.219.108.64] helo=hot-poop.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1m3NNj-00D8yA-2s; Tue, 13 Jul 2021 19:43:47 +0100 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: wnliu@google.com, Moritz Fischer , stable@vger.kernel.org, Ard Biesheuvel , James Morse , Catalin Marinas , Will Deacon Subject: [PATCH v2] firmware/efi: Tell memblock about EFI iomem reservations Date: Tue, 13 Jul 2021 19:43:26 +0100 Message-Id: <20210713184326.570923-1-maz@kernel.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, wnliu@google.com, mdf@kernel.org, stable@vger.kernel.org, ardb@kernel.org, james.morse@arm.com, catalin.marinas@arm.com, will@kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org kexec_load_file() relies on the memblock infrastructure to avoid stamping over regions of memory that are essential to the survival of the system. However, nobody seems to agree how to flag these regions as reserved, and (for example) EFI only publishes its reservations in /proc/iomem for the benefit of the traditional, userspace based kexec tool. On arm64 platforms with GICv3, this can result in the payload being placed at the location of the LPI tables. Shock, horror! Let's augment the EFI reservation code with a memblock_reserve() call, protecting our dear tables from the secondary kernel invasion. Reported-by: Moritz Fischer Tested-by: Moritz Fischer Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org Cc: Ard Biesheuvel Cc: James Morse Cc: Catalin Marinas Cc: Will Deacon --- drivers/firmware/efi/efi.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 4b7ee3fa9224..847f33ffc4ae 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -896,6 +896,7 @@ static int __init efi_memreserve_map_root(void) static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size) { struct resource *res, *parent; + int ret; res = kzalloc(sizeof(struct resource), GFP_ATOMIC); if (!res) @@ -908,7 +909,17 @@ static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size) /* we expect a conflict with a 'System RAM' region */ parent = request_resource_conflict(&iomem_resource, res); - return parent ? request_resource(parent, res) : 0; + ret = parent ? request_resource(parent, res) : 0; + + /* + * Given that efi_mem_reserve_iomem() can be called at any + * time, only call memblock_reserve() if the architecture + * keeps the infrastructure around. + */ + if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK) && !ret) + memblock_reserve(addr, size); + + return ret; } int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size) -- 2.30.2