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=-11.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 A7A2FC2BA83 for ; Wed, 12 Feb 2020 12:04:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 81B082082F for ; Wed, 12 Feb 2020 12:04:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727535AbgBLMEx (ORCPT ); Wed, 12 Feb 2020 07:04:53 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:48419 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728452AbgBLMEn (ORCPT ); Wed, 12 Feb 2020 07:04:43 -0500 Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1j1qkw-0003Zu-UF; Wed, 12 Feb 2020 13:04:39 +0100 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 8B67D1C2005; Wed, 12 Feb 2020 13:04:37 +0100 (CET) Date: Wed, 12 Feb 2020 12:04:37 -0000 From: "tip-bot2 for Arvind Sankar" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/boot] x86/boot/compressed/64: Use 32-bit (zero-extended) MOV for z_output_len Cc: Arvind Sankar , Borislav Petkov , x86 , LKML In-Reply-To: <20200211173333.1722739-1-nivedita@alum.mit.edu> References: <20200211173333.1722739-1-nivedita@alum.mit.edu> MIME-Version: 1.0 Message-ID: <158150907715.411.11504187337643136234.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/boot branch of tip: Commit-ID: a86255fe5258714e1f7c1bdfe95f08e4d098d450 Gitweb: https://git.kernel.org/tip/a86255fe5258714e1f7c1bdfe95f08e4d098d450 Author: Arvind Sankar AuthorDate: Tue, 11 Feb 2020 12:33:33 -05:00 Committer: Borislav Petkov CommitterDate: Wed, 12 Feb 2020 11:15:31 +01:00 x86/boot/compressed/64: Use 32-bit (zero-extended) MOV for z_output_len z_output_len is the size of the decompressed payload (i.e. vmlinux + vmlinux.relocs) and is generated as an unsigned 32-bit quantity by mkpiggy.c. The current movq $z_output_len, %r9 instruction generates a sign-extended move to %r9. Using movl $z_output_len, %r9d will instead zero-extend into %r9, which is appropriate for an unsigned 32-bit quantity. This is also what is already done for z_input_len, the size of the compressed payload. [ bp: Also, z_output_len cannot be a 64-bit quantity because it participates in: init_size: .long INIT_SIZE # kernel initialization size through INIT_SIZE which is a 32-bit quantity determined by the .long directive (vs .quad for 64-bit). Furthermore, if it really must be a 64-bit quantity, then the insn must be MOVABS which can accommodate a 64-bit immediate and which the toolchain does not generate automatically. ] Signed-off-by: Arvind Sankar Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20200211173333.1722739-1-nivedita@alum.mit.edu --- arch/x86/boot/compressed/head_64.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index d1220de..68f31c4 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -482,7 +482,7 @@ SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated) leaq input_data(%rip), %rdx /* input_data */ movl $z_input_len, %ecx /* input_len */ movq %rbp, %r8 /* output target address */ - movq $z_output_len, %r9 /* decompressed length, end of relocs */ + movl $z_output_len, %r9d /* decompressed length, end of relocs */ call extract_kernel /* returns kernel location in %rax */ popq %rsi