From patchwork Mon Aug 7 18:35:59 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 9885977 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 901FE603B4 for ; Mon, 7 Aug 2017 18:39:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 858D224151 for ; Mon, 7 Aug 2017 18:39:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7A34E283AE; Mon, 7 Aug 2017 18:39:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 6D16224151 for ; Mon, 7 Aug 2017 18:39:12 +0000 (UTC) Received: (qmail 10179 invoked by uid 550); 7 Aug 2017 18:38:42 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 10011 invoked from network); 7 Aug 2017 18:38:40 -0000 From: Mark Rutland To: linux-arm-kernel@lists.infradead.org Cc: ard.biesheuvel@linaro.org, catalin.marinas@arm.com, james.morse@arm.com, labbott@redhat.com, linux-kernel@vger.kernel.org, luto@amacapital.net, mark.rutland@arm.com, matt@codeblueprint.co.uk, will.deacon@arm.com, kernel-hardening@lists.openwall.com, keescook@chromium.org Date: Mon, 7 Aug 2017 19:35:59 +0100 Message-Id: <1502130965-18710-9-git-send-email-mark.rutland@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1502130965-18710-1-git-send-email-mark.rutland@arm.com> References: <1502130965-18710-1-git-send-email-mark.rutland@arm.com> Subject: [kernel-hardening] [PATCH 08/14] efi/arm64: add EFI_KIMG_ALIGN X-Virus-Scanned: ClamAV using ClamSMTP The EFI stub is intimately coupled with the kernel, and takes advantage of this by relocating the kernel at a weaker alignment than the documented boot protocol mandates. However, it does so by assuming it can align the kernel to the segment alignment, and assumes that this is 64K. In subsequent patches, we'll have to consider other details to determine this de-facto alignment constraint. This patch adds a new EFI_KIMG_ALIGN definition that will track the kernel's de-facto alignment requirements. Subsequent patches will modify this as required. Signed-off-by: Mark Rutland Cc: Ard Biesheuvel Cc: Catalin Marinas Cc: James Morse Cc: Laura Abbott Cc: Matt Fleming Cc: Will Deacon --- arch/arm64/include/asm/efi.h | 3 +++ drivers/firmware/efi/libstub/arm64-stub.c | 6 ++++-- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h index 8f3043a..0e8cc3b 100644 --- a/arch/arm64/include/asm/efi.h +++ b/arch/arm64/include/asm/efi.h @@ -4,6 +4,7 @@ #include #include #include +#include #include #include #include @@ -48,6 +49,8 @@ */ #define EFI_FDT_ALIGN SZ_2M /* used by allocate_new_fdt_and_exit_boot() */ +#define EFI_KIMG_ALIGN SEGMENT_ALIGN + /* on arm64, the FDT may be located anywhere in system RAM */ static inline unsigned long efi_get_max_fdt_addr(unsigned long dram_base) { diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c index b4c2589..af6ae95 100644 --- a/drivers/firmware/efi/libstub/arm64-stub.c +++ b/drivers/firmware/efi/libstub/arm64-stub.c @@ -11,6 +11,7 @@ */ #include #include +#include #include #include @@ -81,9 +82,10 @@ efi_status_t handle_kernel_image(efi_system_table_t *sys_table_arg, /* * If CONFIG_DEBUG_ALIGN_RODATA is not set, produce a * displacement in the interval [0, MIN_KIMG_ALIGN) that - * is a multiple of the minimal segment alignment (SZ_64K) + * doesn't violate this kernel's de-facto alignment + * constraints. */ - u32 mask = (MIN_KIMG_ALIGN - 1) & ~(SZ_64K - 1); + u32 mask = (MIN_KIMG_ALIGN - 1) & ~(EFI_KIMG_ALIGN - 1); u32 offset = !IS_ENABLED(CONFIG_DEBUG_ALIGN_RODATA) ? (phys_seed >> 32) & mask : TEXT_OFFSET;