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,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 6797FCA9EAE for ; Tue, 29 Oct 2019 17:39:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3DA2A208E3 for ; Tue, 29 Oct 2019 17:39:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572370755; bh=5JAEhpTmrGeng4o8SZlsF0+eWo/frFdlcFrUqJ8GBk8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tgEU2hpnTSjPljLz5hdhmes+T/FqNjK45nDTlTnCwv6HjZ70lfwur09qxUixbZz2u Yj2SfQtCcY255Nh47MqsNg3qFavmsc03VQ9y81rHtlADV9kpYyJix23Df/ZevySq7a Ze2By6AjjPZ+brNc52LeJRV1A7Dn7XDA68mDUWHg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729139AbfJ2RjO (ORCPT ); Tue, 29 Oct 2019 13:39:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:53168 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728917AbfJ2RjL (ORCPT ); Tue, 29 Oct 2019 13:39:11 -0400 Received: from e123331-lin.home (lfbn-mar-1-643-104.w90-118.abo.wanadoo.fr [90.118.215.104]) (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 CECF421721; Tue, 29 Oct 2019 17:39:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572370750; bh=5JAEhpTmrGeng4o8SZlsF0+eWo/frFdlcFrUqJ8GBk8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vv0PYDMraLkh4sDr3+6X1vwPIopcRMaMBnkph91GAN+rMrEgqREA5hPDq/t/fv360 MZNSQVT1uHv+5LbQNbe/3ejZgIPtM+fm3gWHW6lCR5dmYEFrdWtcixAdrnmnKd+RSb bGmOXLWSU4/h0fmfwGd1F9sTC05aj4LAcsiZnGaA= From: Ard Biesheuvel To: linux-efi@vger.kernel.org, Ingo Molnar , Thomas Gleixner Cc: Ard Biesheuvel , linux-kernel@vger.kernel.org Subject: [PATCH v2 4/6] efi: libstub/arm: account for firmware reserved memory at the base of RAM Date: Tue, 29 Oct 2019 18:37:53 +0100 Message-Id: <20191029173755.27149-5-ardb@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191029173755.27149-1-ardb@kernel.org> References: <20191029173755.27149-1-ardb@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ard Biesheuvel The EFI stubloader for ARM starts out by allocating a 32 MB window at the base of RAM, in order to ensure that the decompressor (which blindly copies the uncompressed kernel into that window) does not overwrite other allocations that are made while running in the context of the EFI firmware. In some cases, (e.g., U-Boot running on the Raspberry Pi 2), this is causing boot failures because this initial allocation conflicts with a page of reserved memory at the base of RAM that contains the SMP spin tables and other pieces of firmware data and which was put there by the bootloader under the assumption that the TEXT_OFFSET window right below the kernel is only used partially during early boot, and will be left alone once the memory reservations are processed and taken into account. So let's permit reserved memory regions to exist in the region starting at the base of RAM, and ending at TEXT_OFFSET - 5 * PAGE_SIZE, which is the window below the kernel that is not touched by the early boot code. Acked-by: Chester Lin Tested-by: Guillaume Gardet Signed-off-by: Ard Biesheuvel --- drivers/firmware/efi/libstub/Makefile | 1 + drivers/firmware/efi/libstub/arm32-stub.c | 16 +++++++++++++--- 2 files changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 0460c7581220..ee0661ddb25b 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -52,6 +52,7 @@ lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o string.o random.o \ lib-$(CONFIG_ARM) += arm32-stub.o lib-$(CONFIG_ARM64) += arm64-stub.o +CFLAGS_arm32-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) # diff --git a/drivers/firmware/efi/libstub/arm32-stub.c b/drivers/firmware/efi/libstub/arm32-stub.c index e8f7aefb6813..ffa242ad0a82 100644 --- a/drivers/firmware/efi/libstub/arm32-stub.c +++ b/drivers/firmware/efi/libstub/arm32-stub.c @@ -195,6 +195,7 @@ efi_status_t handle_kernel_image(efi_system_table_t *sys_table, unsigned long dram_base, efi_loaded_image_t *image) { + unsigned long kernel_base; efi_status_t status; /* @@ -204,9 +205,18 @@ efi_status_t handle_kernel_image(efi_system_table_t *sys_table, * loaded. These assumptions are made by the decompressor, * before any memory map is available. */ - dram_base = round_up(dram_base, SZ_128M); + kernel_base = round_up(dram_base, SZ_128M); - status = reserve_kernel_base(sys_table, dram_base, reserve_addr, + /* + * Note that some platforms (notably, the Raspberry Pi 2) put + * spin-tables and other pieces of firmware at the base of RAM, + * abusing the fact that the window of TEXT_OFFSET bytes at the + * base of the kernel image is only partially used at the moment. + * (Up to 5 pages are used for the swapper page tables) + */ + kernel_base += TEXT_OFFSET - 5 * PAGE_SIZE; + + status = reserve_kernel_base(sys_table, kernel_base, reserve_addr, reserve_size); if (status != EFI_SUCCESS) { pr_efi_err(sys_table, "Unable to allocate memory for uncompressed kernel.\n"); @@ -220,7 +230,7 @@ efi_status_t handle_kernel_image(efi_system_table_t *sys_table, *image_size = image->image_size; status = efi_relocate_kernel(sys_table, image_addr, *image_size, *image_size, - dram_base + MAX_UNCOMP_KERNEL_SIZE, 0); + kernel_base + MAX_UNCOMP_KERNEL_SIZE, 0); if (status != EFI_SUCCESS) { pr_efi_err(sys_table, "Failed to relocate kernel.\n"); efi_free(sys_table, *reserve_size, *reserve_addr); -- 2.17.1