From patchwork Wed Feb 8 11:55:44 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 93617 Delivered-To: patch@linaro.org Received: by 10.140.20.99 with SMTP id 90csp2648892qgi; Wed, 8 Feb 2017 04:05:19 -0800 (PST) X-Received: by 10.98.223.66 with SMTP id u63mr25715072pfg.39.1486555519045; Wed, 08 Feb 2017 04:05:19 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id 72si6933694pfj.150.2017.02.08.04.05.18; Wed, 08 Feb 2017 04:05:19 -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 S932099AbdBHMFG (ORCPT + 2 others); Wed, 8 Feb 2017 07:05:06 -0500 Received: from mail-wm0-f52.google.com ([74.125.82.52]:36405 "EHLO mail-wm0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932096AbdBHMEw (ORCPT ); Wed, 8 Feb 2017 07:04:52 -0500 Received: by mail-wm0-f52.google.com with SMTP id c85so194513255wmi.1 for ; Wed, 08 Feb 2017 04:04:51 -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:in-reply-to:references; bh=B9AA5JhlhklbDBxypnaXasxNRovST2QF7QshWwi2npA=; b=R1Ax7ARTHMu2XeV0BQJW75IGdZ3Kpi2HG/g7VVJBix+AqAKZWSlHf2arwyriw6TtdV soDwba/3+SCcenE0OLFMYt/xveLO1i/HytFnj+LiFUJIokzdylQtC/17H2v2rndj2rXl nzukSg+Dl3uLzDFrp+HlcWMga9F16nMghkp+A= 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:in-reply-to :references; bh=B9AA5JhlhklbDBxypnaXasxNRovST2QF7QshWwi2npA=; b=EUoC+LUeVb0jUBCCclEtu2Ghcc/g9iHcqLX/sg7f9ucO/y/LEe7hECX0L00md+J0v0 HmNLAOhMfrAQE6k+MonpLBzUfQRjGt/oLTE2uefseWtb2O1pJCDWwrHifvcLAWwiSV1w oQqzSH2e09GqplbjSlIqat8SFsx0piHRisSobtz0lbP4YkEicsE/rEUCUzndHA1z5S9s 8DBSsn81XGQjG4wgFNKBwqGiohr/8UCxt6BVoggqyGKooBJKw0VcqQEbOsbF0PERqPo5 tJVeOCTNRGW+k8Pk8hRZc+FjuHS3Z5uGEidLD4QJ1H2bX0k+OpbGO7A345B98KXJskrS Cm8Q== X-Gm-Message-State: AMke39nuC8OTEu2Q/Jpg6jsyM3igvUTK1yRLB4pvdE5159zoiNwUUAxUF8k5S+PSNwWejxOP X-Received: by 10.28.207.70 with SMTP id f67mr16564500wmg.72.1486554991195; Wed, 08 Feb 2017 03:56:31 -0800 (PST) Received: from localhost.localdomain ([160.169.163.122]) by smtp.gmail.com with ESMTPSA id 123sm2974815wml.6.2017.02.08.03.56.28 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 08 Feb 2017 03:56:30 -0800 (PST) From: Ard Biesheuvel To: linux-efi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, mark.rutland@arm.com, leif.lindholm@linaro.org Cc: catalin.marinas@arm.com, linux@armlinux.org.uk, kernel-hardening@lists.openwall.com, labbott@fedoraproject.org, Ard Biesheuvel Subject: [PATCH v2 11/14] arm: efi: remove pointless dummy .reloc section Date: Wed, 8 Feb 2017 11:55:44 +0000 Message-Id: <1486554947-3964-12-git-send-email-ard.biesheuvel@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1486554947-3964-1-git-send-email-ard.biesheuvel@linaro.org> References: <1486554947-3964-1-git-send-email-ard.biesheuvel@linaro.org> Sender: linux-efi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org The kernel's EFI PE/COFF header contains a dummy .reloc section, and an explanatory comment that claims that this is required for the EFI application loader to accept the Image as a relocatable image (i.e., one that can be loaded at any offset and fixed up in place) This was inherited from the x86 implementation, which has elaborate host tooling to mangle the PE/COFF header post-link time, and which populates the .reloc section with a single dummy base relocation. On ARM, no such tooling exists, and the .reloc section remains empty, and is never even exposed via the BaseRelocationTable directory entry, which is where the PE/COFF loader looks for it. The PE/COFF spec is unclear about relocatable images that do not require any fixups, but the EDK2 implementation, which is the de facto reference for PE/COFF in the UEFI space, clearly does not care, and explicitly mentions (in a comment) that relocatable images with no base relocations are perfectly fine, as long as they don't have the RELOCS_STRIPPED attribute set (which is not the case for our PE/COFF image) So simply remove the .reloc section altogether. Signed-off-by: Ard Biesheuvel --- arch/arm/boot/compressed/efi-header.S | 18 +----------------- 1 file changed, 1 insertion(+), 17 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 diff --git a/arch/arm/boot/compressed/efi-header.S b/arch/arm/boot/compressed/efi-header.S index 50eff3bbc57c..5873fc2b5f9a 100644 --- a/arch/arm/boot/compressed/efi-header.S +++ b/arch/arm/boot/compressed/efi-header.S @@ -40,7 +40,7 @@ pe_header: coff_header: .short 0x01c2 @ ARM or Thumb - .short 2 @ nr_sections + .short 1 @ nr_sections .long 0 @ TimeDateStamp .long 0 @ PointerToSymbolTable .long 0 @ NumberOfSymbols @@ -95,22 +95,6 @@ extra_header_fields: .quad 0 @ BaseRelocationTable section_table: - @ - @ The EFI application loader requires a relocation section - @ because EFI applications must be relocatable. This is a - @ dummy section as far as we are concerned. - @ - .ascii ".reloc\0\0" - .long 0 @ VirtualSize - .long 0 @ VirtualAddress - .long 0 @ SizeOfRawData - .long 0 @ PointerToRawData - .long 0 @ PointerToRelocations - .long 0 @ PointerToLineNumbers - .short 0 @ NumberOfRelocations - .short 0 @ NumberOfLineNumbers - .long 0x42000040 @ Characteristics - .ascii ".text\0\0\0" .long _end - __efi_start @ VirtualSize .long __efi_start @ VirtualAddress