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=-13.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 BAE05C5519F for ; Tue, 17 Nov 2020 12:48:44 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 292CC2222A for ; Tue, 17 Nov 2020 12:48:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ZbZ50Cz9"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="TGjkZ7iL" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 292CC2222A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=PVckYTYGR7V9OYstJDa1NgztyD+yIzbqMIRvKtk7czI=; b=ZbZ50Cz9yVeFkFsbWShRfSLuJ uunrOF4snpqrn7stwPaJEMB8Sstt3yOIwcZRsfWkrL3vCWJ9eP11Dofgp+vvsecoybVYF+7smbt8s GVFwv+TNaPvFdzbZmtlWRzvrpYRbxG3IL+k94tKzYHgGgjq26QWW6jiGoYwwG+eA3zA2BfOcyqN5c FqQJJ5jf8WQIJizQT2DJHittB/3WDhiHbvgMtNtnOcs7qyuJMisWghWS4k8Sl8y3u21KlWeqg/7/t Xyd7wVwLi/MwXJp3QwPRFXG5uI6537fWx9/0fbhBRkRNp7ZgB3Khr+MWVJvphMd5qZ1iVzUK5lUnQ OC8uA+kdw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kf0PA-0007Gq-QU; Tue, 17 Nov 2020 12:48:16 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kf0P2-0007F3-QB for linux-arm-kernel@lists.infradead.org; Tue, 17 Nov 2020 12:48:10 +0000 Received: from localhost.localdomain (82-64-249-211.subs.proxad.net [82.64.249.211]) (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 7CE362222B; Tue, 17 Nov 2020 12:48:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605617288; bh=l/hr6XzwpnTONiWmZ0kRqAr+dSgdjLlQrNW/085q3PU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TGjkZ7iLr5X1jPwyUkVTK6QypbuUla+3S/1nuifYtO7XseHb8iZSMURfRJ5vTUVN+ aVHwYpwd0eDlN3WzMFj/97p5jh/63EkiE3qP6GbUkjq/jSh4Gg9vTVhFwGBId3t2Ci foY0CCWHggpfJHHZj3YA+L1Iqqj6MoeEdCFo2Dic= From: Ard Biesheuvel To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 3/3] arm64: head: tidy up the Image header definition Date: Tue, 17 Nov 2020 13:47:29 +0100 Message-Id: <20201117124729.12642-4-ardb@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20201117124729.12642-1-ardb@kernel.org> References: <20201117124729.12642-1-ardb@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201117_074809_044349_D41D9365 X-CRM114-Status: GOOD ( 19.05 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, will@kernel.org, catalin.marinas@arm.com, james.morse@arm.com, robin.murphy@arm.com, Ard Biesheuvel Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Even though support for EFI boot remains entirely optional for arm64, it is unlikely that we will ever be able to repurpose the image header fields that the EFI loader relies on, i.e., the magic NOP at offset 0x0 and the PE header address at offset 0x3c. So let's factor out the differences into a 'efi_signature_nop' macro and a local symbol representing the PE header address, and move the conditional definitions into efi-header.S, taking into account whether CONFIG_EFI is enabled or not. While at it, switch to a signature NOP that behaves more like a NOP, i.e., one that only clobbers the flags. Signed-off-by: Ard Biesheuvel Acked-by: Will Deacon --- arch/arm64/kernel/efi-header.S | 43 +++++++++++++++----- arch/arm64/kernel/head.S | 19 +-------- 2 files changed, 35 insertions(+), 27 deletions(-) diff --git a/arch/arm64/kernel/efi-header.S b/arch/arm64/kernel/efi-header.S index ddaf57d825b5..28d8a5dca5f1 100644 --- a/arch/arm64/kernel/efi-header.S +++ b/arch/arm64/kernel/efi-header.S @@ -7,7 +7,27 @@ #include #include + .macro efi_signature_nop +#ifdef CONFIG_EFI +.L_head: + /* + * This ccmp instruction has no meaningful effect except that + * its opcode forms the magic "MZ" signature required by UEFI. + */ + ccmp x18, #0, #0xd, pl +#else + /* + * Bootloaders may inspect the opcode at the start of the kernel + * image to decide if the kernel is capable of booting via UEFI. + * So put an ordinary NOP here, not the "MZ.." pseudo-nop above. + */ + nop +#endif + .endm + .macro __EFI_PE_HEADER +#ifdef CONFIG_EFI + .set .Lpe_header_offset, . - .L_head .long PE_MAGIC .short IMAGE_FILE_MACHINE_ARM64 // Machine .short .Lsection_count // NumberOfSections @@ -26,8 +46,8 @@ .long __initdata_begin - .Lefi_header_end // SizeOfCode .long __pecoff_data_size // SizeOfInitializedData .long 0 // SizeOfUninitializedData - .long __efistub_efi_pe_entry - _head // AddressOfEntryPoint - .long .Lefi_header_end - _head // BaseOfCode + .long __efistub_efi_pe_entry - .L_head // AddressOfEntryPoint + .long .Lefi_header_end - .L_head // BaseOfCode .quad 0 // ImageBase .long SEGMENT_ALIGN // SectionAlignment @@ -40,10 +60,10 @@ .short 0 // MinorSubsystemVersion .long 0 // Win32VersionValue - .long _end - _head // SizeOfImage + .long _end - .L_head // SizeOfImage // Everything before the kernel image is considered part of the header - .long .Lefi_header_end - _head // SizeOfHeaders + .long .Lefi_header_end - .L_head // SizeOfHeaders .long 0 // CheckSum .short IMAGE_SUBSYSTEM_EFI_APPLICATION // Subsystem .short 0 // DllCharacteristics @@ -62,7 +82,7 @@ .quad 0 // BaseRelocationTable #ifdef CONFIG_DEBUG_EFI - .long .Lefi_debug_table - _head // DebugTable + .long .Lefi_debug_table - .L_head // DebugTable .long .Lefi_debug_table_size #endif @@ -70,9 +90,9 @@ .Lsection_table: .ascii ".text\0\0\0" .long __initdata_begin - .Lefi_header_end // VirtualSize - .long .Lefi_header_end - _head // VirtualAddress + .long .Lefi_header_end - .L_head // VirtualAddress .long __initdata_begin - .Lefi_header_end // SizeOfRawData - .long .Lefi_header_end - _head // PointerToRawData + .long .Lefi_header_end - .L_head // PointerToRawData .long 0 // PointerToRelocations .long 0 // PointerToLineNumbers @@ -84,9 +104,9 @@ .ascii ".data\0\0\0" .long __pecoff_data_size // VirtualSize - .long __initdata_begin - _head // VirtualAddress + .long __initdata_begin - .L_head // VirtualAddress .long __pecoff_data_rawsize // SizeOfRawData - .long __initdata_begin - _head // PointerToRawData + .long __initdata_begin - .L_head // PointerToRawData .long 0 // PointerToRelocations .long 0 // PointerToLineNumbers @@ -121,7 +141,7 @@ .long IMAGE_DEBUG_TYPE_CODEVIEW // Type .long .Lefi_debug_entry_size // SizeOfData .long 0 // RVA - .long .Lefi_debug_entry - _head // FileOffset + .long .Lefi_debug_entry - .L_head // FileOffset .set .Lefi_debug_table_size, . - .Lefi_debug_table .previous @@ -140,4 +160,7 @@ .balign SEGMENT_ALIGN .Lefi_header_end: +#else + .set .Lpe_header_offset, 0x0 +#endif .endm diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index d8d9caf02834..c1f8f2c5be47 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -58,21 +58,11 @@ * in the entry routines. */ __HEAD -_head: /* * DO NOT MODIFY. Image header expected by Linux boot-loaders. */ -#ifdef CONFIG_EFI - /* - * This add instruction has no meaningful effect except that - * its opcode forms the magic "MZ" signature required by UEFI. - */ - add x13, x18, #0x16 - b primary_entry -#else + efi_signature_nop // special NOP to identity as PE/COFF executable b primary_entry // branch to kernel start, magic - .long 0 // reserved -#endif .quad 0 // Image load offset from start of RAM, little-endian le64sym _kernel_size_le // Effective size of kernel image, little-endian le64sym _kernel_flags_le // Informative flags, little-endian @@ -80,14 +70,9 @@ _head: .quad 0 // reserved .quad 0 // reserved .ascii ARM64_IMAGE_MAGIC // Magic number -#ifdef CONFIG_EFI - .long pe_header - _head // Offset to the PE header. + .long .Lpe_header_offset // Offset to the PE header. -pe_header: __EFI_PE_HEADER -#else - .long 0 // reserved -#endif __INIT -- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel