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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 4D893CA9EB9 for ; Wed, 23 Oct 2019 05:49:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 24AA021872 for ; Wed, 23 Oct 2019 05:49:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571809763; bh=snDD2TGm/p3To1d+GTgma+dC7mp1sEZRotHc0mSrxgk=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=Wpq06od6ZIrtzgJ43Qdtb+mZcEkFbYK8uFHZM6LBermKZGVG7UZ9z4WX/trom4LYu JuyC3773rFXfQydnOkRh080PiumWc55Z8IvQLTSLkmH1MaK8I6/MssqblTaIQ7hjcY c7xz4W0Xnw9XG/WkFWhgnvRPg98bIBKErsVXyF4g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732691AbfJWFtV (ORCPT ); Wed, 23 Oct 2019 01:49:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:44044 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731847AbfJWFtV (ORCPT ); Wed, 23 Oct 2019 01:49:21 -0400 Received: from devnote2 (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EC981214B2; Wed, 23 Oct 2019 05:49:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571809760; bh=snDD2TGm/p3To1d+GTgma+dC7mp1sEZRotHc0mSrxgk=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=jXp1j7nLsX2w5XE8QjSsMsPsl6XNtnpXMoeAsWx7LgtVt9dh19xs8SCMDNPbgwxPw 6VN5Z0HebFWqLdi6aej3/2KW2YqTHTNy4xg/jI9KXWPKB8I7d7f0qw7Zlc1qKC0QQ9 a4iUCnJ0h0ATuVIBaLQ15t9K3Wj/afO/hHwllWRU= Date: Wed, 23 Oct 2019 14:49:16 +0900 From: Masami Hiramatsu To: Randy Dunlap Cc: Stephen Rothwell , Linux Next Mailing List , Linux Kernel Mailing List , Josh Poimboeuf , Masami Hiramatsu Subject: Re: linux-next: Tree for Oct 14 (insn_decoder_test) Message-Id: <20191023144916.2cbd0ea16363b4cd4574f5ad@kernel.org> In-Reply-To: <2d83682b-6206-4992-63cc-342d61641c0a@infradead.org> References: <20191014174707.469f596f@canb.auug.org.au> <2d83682b-6206-4992-63cc-342d61641c0a@infradead.org> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Mon, 14 Oct 2019 08:30:02 -0700 Randy Dunlap wrote: > On 10/13/19 11:47 PM, Stephen Rothwell wrote: > > Hi all, > > > > Changes since 20191011: > > > > on x86_64: > > HOSTCC arch/x86/tools/insn_decoder_test > HOSTCC arch/x86/tools/insn_sanity > TEST posttest > arch/x86/tools/insn_decoder_test: warning: Found an x86 instruction decoder bug, please report this. > arch/x86/tools/insn_decoder_test: warning: ffffffff81000bf1: f7 0b 00 01 08 00 testl $0x80100,(%rbx) > arch/x86/tools/insn_decoder_test: warning: objdump says 6 bytes, but insn_get_length() says 2 > arch/x86/tools/insn_decoder_test: warning: Decoded and checked 11913894 instructions with 1 failures > TEST posttest > arch/x86/tools/insn_sanity: Success: decoded and checked 1000000 random instructions with 0 errors (seed:0x871ce29c) Hmm, curious. x86-opcode-map.txt said, f7: Grp3_2 Ev (1A) and "0x0b" is 00001011b, Group encoding bits are 5,4,3 (reg field), so group index is 001. GrpTable: Grp3_2 0: TEST Ev,Iz 1: Hmm, "f7 0b" is not assigned to any instruction... (testl should be f7 03) I've checked Intel SDM May 2019 version(*), but the Opcode Map (Table A-6. Opecode Extensions for One- and Two-byte Opecodes by Group Number) showed the group index 001 is still blank. I've also checked that Table B-13 (General Purpose Instruction Formats and Encodings for Non-64-Bit Modes (Note that this has no REX prefix)) but I couldn't find "f7 0b". At last, I found that on AMD64 Architecture Programmer's Manual Volume 3, Appendix A.2 Table A-6. ModRM.reg Extensions for the Primary Opcode Map(**), which shows that both f7 + reg=000 and f7 + reg=001 are same. So only on AMD64, it is officially available instruction. (*) https://software.intel.com/sites/default/files/managed/a4/60/325383-sdm-vol-2abcd.pdf (**) https://www.amd.com/system/files/TechDocs/24594.pdf OK, so this should be fixed with below patch. ------ >From b3f45b86df25be59fcf417730ab4c69c6310eaad Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 23 Oct 2019 14:45:35 +0900 Subject: [PATCH] x86/decoder: Add TEST opcode to Group3-2 Add TEST opcode to Group3-2 reg=001b as same as Group3-1 does. Commit 12a78d43de76 ("x86/decoder: Add new TEST instruction pattern") added a TEST opcode assignment to f6 XX/001/XXX (Group 3-1), but not added f7 XX/001/XXX (Group 3-2). Actually these TEST opcode is not described in Intel SDM Vol2, but described in AMD64 Architecture Programmer's Manual Vol.3, Appendix A.2 Table A-6. ModRM.reg Extensions for the Primary Opcode Map. Without this fix, Randy found a warning by insn_decoder_test related to this issue as below. HOSTCC arch/x86/tools/insn_decoder_test HOSTCC arch/x86/tools/insn_sanity TEST posttest arch/x86/tools/insn_decoder_test: warning: Found an x86 instruction decoder bug, please report this. arch/x86/tools/insn_decoder_test: warning: ffffffff81000bf1: f7 0b 00 01 08 00 testl $0x80100,(%rbx) arch/x86/tools/insn_decoder_test: warning: objdump says 6 bytes, but insn_get_length() says 2 arch/x86/tools/insn_decoder_test: warning: Decoded and checked 11913894 instructions with 1 failures TEST posttest arch/x86/tools/insn_sanity: Success: decoded and checked 1000000 random instructions with 0 errors (seed:0x871ce29c) To fix this error, add TEST opcode according to AMD64 APM Vol.3. Reported-by: Randy Dunlap Signed-off-by: Masami Hiramatsu --- arch/x86/lib/x86-opcode-map.txt | 2 +- tools/arch/x86/lib/x86-opcode-map.txt | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/lib/x86-opcode-map.txt b/arch/x86/lib/x86-opcode-map.txt index e0b85930dd77..4635ce298d1d 100644 --- a/arch/x86/lib/x86-opcode-map.txt +++ b/arch/x86/lib/x86-opcode-map.txt @@ -907,7 +907,7 @@ EndTable GrpTable: Grp3_2 0: TEST Ev,Iz -1: +1: TEST Ev,Iz 2: NOT Ev 3: NEG Ev 4: MUL rAX,Ev diff --git a/tools/arch/x86/lib/x86-opcode-map.txt b/tools/arch/x86/lib/x86-opcode-map.txt index e0b85930dd77..4635ce298d1d 100644 --- a/tools/arch/x86/lib/x86-opcode-map.txt +++ b/tools/arch/x86/lib/x86-opcode-map.txt @@ -907,7 +907,7 @@ EndTable GrpTable: Grp3_2 0: TEST Ev,Iz -1: +1: TEST Ev,Iz 2: NOT Ev 3: NEG Ev 4: MUL rAX,Ev -- 2.20.1 -- Masami Hiramatsu