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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 D8AA9C43603 for ; Wed, 4 Dec 2019 14:52:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AB5DF206DF for ; Wed, 4 Dec 2019 14:52:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575471152; bh=2Hhr1DoiPHOZk7B+fdoNv2WRhAw5ziTKXzdrxtsKJbw=; h=From:To:Cc:Subject:Date:List-ID:From; b=2AWY6FOObIu4fFy6dWibB8SE29dAM9KdVLcmLd7/Yy4dWohr9OtETKBk0QdmtQ7qY a9Ge9iU74vWZzGvfN79a8uR6E7bHR5J0JlMBGyhBFVr3FPmltOggpPZhzo1lWr/RrV Sw7SKhMh31BuEDtekrT21FtAe7+tkRKTlWOCWGR0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727958AbfLDOwc (ORCPT ); Wed, 4 Dec 2019 09:52:32 -0500 Received: from mail.kernel.org ([198.145.29.99]:37948 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727912AbfLDOwc (ORCPT ); Wed, 4 Dec 2019 09:52:32 -0500 Received: from e123331-lin.cambridge.arm.com (fw-tnat-cam5.arm.com [217.140.106.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B6E012081B; Wed, 4 Dec 2019 14:52:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575471151; bh=2Hhr1DoiPHOZk7B+fdoNv2WRhAw5ziTKXzdrxtsKJbw=; h=From:To:Cc:Subject:Date:From; b=2QKVkLOgtMI2leXLzHm7e90HDOewfx4mqxF9KVzm0dvshjmuh+bQ+rv3IlMhRvl++ pJlfpZtjdipdpNdXZ2+kmQd8Z9Qsrvirh7qicNQCwczJSrrExP5TVi9qCnYui0vO7W HLntdNiPdw/K9HRng3gTvN3qjloPA4/z3q+Lu3q8= From: Ard Biesheuvel To: linux-efi@vger.kernel.org Cc: mark.rutland@arm.com, james.morse@arm.com, Ard Biesheuvel , Masayoshi Mizuma , d.hatayama@fujitsu.com, kexec@lists.infradead.org Subject: [PATCH] efi/memreserve: register reservations as 'reserved' in /proc/iomem Date: Wed, 4 Dec 2019 14:52:33 +0000 Message-Id: <20191204145233.11962-1-ardb@kernel.org> X-Mailer: git-send-email 2.17.1 Sender: linux-efi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org Memory regions that are reserved using efi_mem_reserve_persistent() are recorded in a special EFI config table which survives kexec, allowing the incoming kernel to honour them as well. However, such reservations are not visible in /proc/iomem, and so the kexec tools that load the incoming kernel and its initrd into memory may overwrite these reserved regions before the incoming kernel has a chance to reserve them from further use. So add these reservations to /proc/iomem as they are created. Note that reservations that are inherited from a previous kernel are memblock_reserve()'d early on, so they are already visible in /proc/iomem. Cc: Masayoshi Mizuma Cc: d.hatayama@fujitsu.com Cc: kexec@lists.infradead.org Signed-off-by: Ard Biesheuvel --- drivers/firmware/efi/efi.c | 29 ++++++++++++++++++-- 1 file changed, 26 insertions(+), 3 deletions(-) diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index d101f072c8f8..fcd82dde23c8 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -979,6 +979,24 @@ static int __init efi_memreserve_map_root(void) return 0; } +static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size) +{ + struct resource *res, *parent; + + res = kzalloc(sizeof(struct resource), GFP_ATOMIC); + if (!res) + return -ENOMEM; + + res->name = "reserved"; + res->flags = IORESOURCE_MEM; + res->start = addr; + res->end = addr + size - 1; + + /* we expect a conflict with a 'System RAM' region */ + parent = request_resource_conflict(&iomem_resource, res); + return parent ? request_resource(parent, res) : 0; +} + int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size) { struct linux_efi_memreserve *rsv; @@ -1001,9 +1019,8 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size) if (index < rsv->size) { rsv->entry[index].base = addr; rsv->entry[index].size = size; - memunmap(rsv); - return 0; + return efi_mem_reserve_iomem(addr, size); } memunmap(rsv); } @@ -1013,6 +1030,12 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size) if (!rsv) return -ENOMEM; + rc = efi_mem_reserve_iomem(__pa(rsv), SZ_4K); + if (rc) { + free_page(rsv); + return rc; + } + /* * The memremap() call above assumes that a linux_efi_memreserve entry * never crosses a page boundary, so let's ensure that this remains true @@ -1029,7 +1052,7 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size) efi_memreserve_root->next = __pa(rsv); spin_unlock(&efi_mem_reserve_persistent_lock); - return 0; + return efi_mem_reserve_iomem(addr, size); } static int __init efi_memreserve_root_init(void) -- 2.17.1