From patchwork Thu Feb 9 21:42:52 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 93782 Delivered-To: patch@linaro.org Received: by 10.140.20.99 with SMTP id 90csp221002qgi; Thu, 9 Feb 2017 14:07:41 -0800 (PST) X-Received: by 10.99.143.90 with SMTP id r26mr6627705pgn.128.1486678061314; Thu, 09 Feb 2017 14:07:41 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id m63si11262745pfc.123.2017.02.09.14.07.41; Thu, 09 Feb 2017 14:07:41 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-efi-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=neutral (body hash did not verify) header.i=@linaro.org; spf=pass (google.com: best guess record for domain of linux-efi-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-efi-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752296AbdBIWHk (ORCPT + 2 others); Thu, 9 Feb 2017 17:07:40 -0500 Received: from mail-wr0-f182.google.com ([209.85.128.182]:36308 "EHLO mail-wr0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751111AbdBIWHj (ORCPT ); Thu, 9 Feb 2017 17:07:39 -0500 Received: by mail-wr0-f182.google.com with SMTP id k90so93751937wrc.3 for ; Thu, 09 Feb 2017 14:07:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id; bh=32mQw3cfpTtQclsa5t4DZRTai4+P01Tx4MzRtHOtWAQ=; b=Dpb3/o/7glQjsEPxuT6+a/dbHWRx1/APHkrjVrERfn8w3FAOBL5DpQk6ek3l8/KKbv MVdjEu9qSVn2a8CBh0IgoiTniWwUBLJBiIK0KrsccA5mqGtNItIxlF0B8jbPRlHFpdmn qoF9h98VZk1/xvvIl+MeZtrs/EHbg4c4cmpdc= 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; bh=32mQw3cfpTtQclsa5t4DZRTai4+P01Tx4MzRtHOtWAQ=; b=Jr1Pwjl78nC4zXmPY3AvPyy+H+UEkDAljxqYAj9Uc5UKOVsM0UgT9Fnjs2eelyOgV6 Md5Ro0OsRuXwkTyLJ6qtTWCwmtSCicZ1eXEeCyPbih0vS5Gi2rXnbhplIFr8+DyAaIew vIaJnX69jqSo6X9p4rMy4tDECJ5FCAtU5OpIsgrHk0DQMt4QWs2trsDpIqUi1t/TeUty aD7p15mjQx80aOyKP2iftfUU1RQsBBo3XVFcdQeBqmDLlKAOhW/z3lTbOKis6zF2tLc+ BdCT+d3D7VwMVamCN/4HpOfif6dhuRsHfsgp4uZ8UCe9EDrbNr3OrN7IY+Pf8pd6z8z2 S49g== X-Gm-Message-State: AMke39k/QST8UsjNH836y3I1LkNNpVgdGsx+QIurS6Ul7U8AcnWmfiQfmtjOhiTIzo0Pq4Xs X-Received: by 10.223.133.226 with SMTP id 31mr4477147wru.137.1486676590855; Thu, 09 Feb 2017 13:43:10 -0800 (PST) Received: from localhost.localdomain ([160.169.163.122]) by smtp.gmail.com with ESMTPSA id x25sm20493047wrx.27.2017.02.09.13.43.07 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 09 Feb 2017 13:43:10 -0800 (PST) From: Ard Biesheuvel To: linux-efi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, matt@codeblueprint.co.uk, mark.rutland@arm.com Cc: timur@codeaurora.org, jhugo@codeaurora.org, leif.lindholm@linaro.org, catalin.marinas@arm.com, Ard Biesheuvel Subject: [PATCH v2 1/2] efi: arm-stub: Correct FDT and initrd allocation rules for arm64 Date: Thu, 9 Feb 2017 21:42:52 +0000 Message-Id: <1486676573-19237-1-git-send-email-ard.biesheuvel@linaro.org> X-Mailer: git-send-email 2.7.4 Sender: linux-efi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org On arm64, we have made some changes over the past year to the way the kernel itself is allocated and to how it deals with the initrd and FDT. This patch brings the allocation logic in the EFI stub in line with that, which is necessary because the introduction of KASLR has created the possibility for the initrd to be allocated in a place where the kernel may not be able to map it. (This is mostly a theoretical scenario, since it only affects systems where the physical memory footprint exceeds the size of the linear mapping.) Since we know the kernel itself will be covered by the linear mapping, choose a suitably sized window (i.e., based on the size of the linear region) covering the kernel when allocating memory for the initrd. The FDT may be anywhere in memory on arm64 now that we map it via the fixmap, so we can lift the address restriction there completely. Signed-off-by: Ard Biesheuvel --- arch/arm/include/asm/efi.h | 14 +++++++++++++- arch/arm64/include/asm/efi.h | 18 +++++++++++++++++- drivers/firmware/efi/libstub/arm-stub.c | 7 ++++--- 3 files changed, 34 insertions(+), 5 deletions(-) -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Reviewed-By: Jeffrey Hugo diff --git a/arch/arm/include/asm/efi.h b/arch/arm/include/asm/efi.h index 0b06f5341b45..2de0195dfd1e 100644 --- a/arch/arm/include/asm/efi.h +++ b/arch/arm/include/asm/efi.h @@ -84,6 +84,18 @@ static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt) */ #define ZIMAGE_OFFSET_LIMIT SZ_128M #define MIN_ZIMAGE_OFFSET MAX_UNCOMP_KERNEL_SIZE -#define MAX_FDT_OFFSET ZIMAGE_OFFSET_LIMIT + +/* on ARM, the FDT should be located in the first 128 MB of RAM */ +static inline unsigned long efi_get_max_fdt_addr(unsigned long dram_base) +{ + return dram_base + ZIMAGE_OFFSET_LIMIT; +} + +/* on ARM, the initrd should be loaded in a lowmem region */ +static inline unsigned long efi_get_max_initrd_addr(unsigned long dram_base, + unsigned long image_addr) +{ + return dram_base + SZ_512M; +} #endif /* _ASM_ARM_EFI_H */ diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h index 0b6b1633017f..342e90d6d204 100644 --- a/arch/arm64/include/asm/efi.h +++ b/arch/arm64/include/asm/efi.h @@ -46,7 +46,23 @@ int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md); * 2MiB so we know it won't cross a 2MiB boundary. */ #define EFI_FDT_ALIGN SZ_2M /* used by allocate_new_fdt_and_exit_boot() */ -#define MAX_FDT_OFFSET SZ_512M + +/* on arm64, the FDT may be located anywhere in system RAM */ +static inline unsigned long efi_get_max_fdt_addr(unsigned long dram_base) +{ + return ULONG_MAX; +} + +/* + * On arm64, we have to ensure that the initrd ends up in the linear region, + * which is a 1 GB aligned region of size '1UL << (VA_BITS - 1)' that is + * guaranteed to cover the kernel Image. + */ +static inline unsigned long efi_get_max_initrd_addr(unsigned long dram_base, + unsigned long image_addr) +{ + return (image_addr & ~(SZ_1G - 1UL)) + (1UL << (VA_BITS - 1)); +} #define efi_call_early(f, ...) sys_table_arg->boottime->f(__VA_ARGS__) #define __efi_call_early(f, ...) f(__VA_ARGS__) diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c index b4f7d78f9e8b..557281fe375f 100644 --- a/drivers/firmware/efi/libstub/arm-stub.c +++ b/drivers/firmware/efi/libstub/arm-stub.c @@ -333,8 +333,9 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table, if (!fdt_addr) pr_efi(sys_table, "Generating empty DTB\n"); - status = handle_cmdline_files(sys_table, image, cmdline_ptr, - "initrd=", dram_base + SZ_512M, + status = handle_cmdline_files(sys_table, image, cmdline_ptr, "initrd=", + efi_get_max_initrd_addr(dram_base, + *image_addr), (unsigned long *)&initrd_addr, (unsigned long *)&initrd_size); if (status != EFI_SUCCESS) @@ -344,7 +345,7 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table, new_fdt_addr = fdt_addr; status = allocate_new_fdt_and_exit_boot(sys_table, handle, - &new_fdt_addr, dram_base + MAX_FDT_OFFSET, + &new_fdt_addr, efi_get_max_fdt_addr(dram_base), initrd_addr, initrd_size, cmdline_ptr, fdt_addr, fdt_size);