From patchwork Thu Aug 13 20:34:21 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Masami Hiramatsu X-Patchwork-Id: 41261 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n7DKXppf003600 for ; Thu, 13 Aug 2009 20:33:54 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932390AbZHMUcO (ORCPT ); Thu, 13 Aug 2009 16:32:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756080AbZHMUcO (ORCPT ); Thu, 13 Aug 2009 16:32:14 -0400 Received: from mx2.redhat.com ([66.187.237.31]:58554 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755836AbZHMUcM (ORCPT ); Thu, 13 Aug 2009 16:32:12 -0400 Received: from int-mx2.corp.redhat.com (int-mx2.corp.redhat.com [172.16.27.26]) by mx2.redhat.com (8.13.8/8.13.8) with ESMTP id n7DKVIiJ023823; Thu, 13 Aug 2009 16:31:18 -0400 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx2.corp.redhat.com (8.13.1/8.13.1) with ESMTP id n7DKVHQu027773; Thu, 13 Aug 2009 16:31:17 -0400 Received: from localhost.localdomain (dhcp-100-3-156.bos.redhat.com [10.16.3.156]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id n7DKVEq3024994; Thu, 13 Aug 2009 16:31:14 -0400 From: Masami Hiramatsu Subject: [PATCH -tip v14 02/12] x86: x86 instruction decoder build-time selftest To: Ingo Molnar , Steven Rostedt , lkml Cc: systemtap , kvm , DLE , Masami Hiramatsu , Jim Keniston , Ananth N Mavinakayanahalli , Avi Kivity , Andi Kleen , Christoph Hellwig , "Frank Ch. Eigler" , Frederic Weisbecker , "H. Peter Anvin" , Ingo Molnar , Jason Baron , "K.Prasad" , Lai Jiangshan , Li Zefan , =?utf-8?q?Przemys=C5=82aw?= =?utf-8?q?Pawe=C5=82czyk?= , Roland McGrath , Sam Ravnborg , Srikar Dronamraju , Steven Rostedt , Tom Zanussi , Vegard Nossum Date: Thu, 13 Aug 2009 16:34:21 -0400 Message-ID: <20090813203421.31965.29006.stgit@localhost.localdomain> In-Reply-To: <20090813203403.31965.20973.stgit@localhost.localdomain> References: <20090813203403.31965.20973.stgit@localhost.localdomain> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.58 on 172.16.27.26 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Add a user-space selftest of x86 instruction decoder at kernel build time. When CONFIG_X86_DECODER_SELFTEST=y, Kbuild builds a test harness of x86 instruction decoder and performs it after building vmlinux. The test compares the results of objdump and x86 instruction decoder code and check there are no differences. Signed-off-by: Masami Hiramatsu Signed-off-by: Jim Keniston Cc: Ananth N Mavinakayanahalli Cc: Avi Kivity Cc: Andi Kleen Cc: Christoph Hellwig Cc: Frank Ch. Eigler Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Jason Baron Cc: K.Prasad Cc: Lai Jiangshan Cc: Li Zefan Cc: Przemysław Pawełczyk Cc: Roland McGrath Cc: Sam Ravnborg Cc: Srikar Dronamraju Cc: Steven Rostedt Cc: Tom Zanussi Cc: Vegard Nossum --- arch/x86/Kconfig.debug | 9 +++ arch/x86/Makefile | 3 + arch/x86/tools/Makefile | 15 +++++ arch/x86/tools/distill.awk | 42 +++++++++++++++ arch/x86/tools/test_get_len.c | 113 +++++++++++++++++++++++++++++++++++++++++ 5 files changed, 182 insertions(+), 0 deletions(-) create mode 100644 arch/x86/tools/Makefile create mode 100644 arch/x86/tools/distill.awk create mode 100644 arch/x86/tools/test_get_len.c diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index d105f29..7d0b681 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -186,6 +186,15 @@ config X86_DS_SELFTEST config HAVE_MMIOTRACE_SUPPORT def_bool y +config X86_DECODER_SELFTEST + bool "x86 instruction decoder selftest" + depends on DEBUG_KERNEL + ---help--- + Perform x86 instruction decoder selftests at build time. + This option is useful for checking the sanity of x86 instruction + decoder code. + If unsure, say "N". + # # IO delay types: # diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 1f3851a..f79580c 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -154,6 +154,9 @@ all: bzImage KBUILD_IMAGE := $(boot)/bzImage bzImage: vmlinux +ifeq ($(CONFIG_X86_DECODER_SELFTEST),y) + $(Q)$(MAKE) $(build)=arch/x86/tools posttest +endif $(Q)$(MAKE) $(build)=$(boot) $(KBUILD_IMAGE) $(Q)mkdir -p $(objtree)/arch/$(UTS_MACHINE)/boot $(Q)ln -fsn ../../x86/boot/bzImage $(objtree)/arch/$(UTS_MACHINE)/boot/$@ diff --git a/arch/x86/tools/Makefile b/arch/x86/tools/Makefile new file mode 100644 index 0000000..3dd626b --- /dev/null +++ b/arch/x86/tools/Makefile @@ -0,0 +1,15 @@ +PHONY += posttest +quiet_cmd_posttest = TEST $@ + cmd_posttest = $(OBJDUMP) -d $(objtree)/vmlinux | awk -f $(srctree)/arch/x86/tools/distill.awk | $(obj)/test_get_len + +posttest: $(obj)/test_get_len vmlinux + $(call cmd,posttest) + +hostprogs-y := test_get_len + +# -I needed for generated C source and C source which in the kernel tree. +HOSTCFLAGS_test_get_len.o := -Wall -I$(objtree)/arch/x86/lib/ -I$(srctree)/arch/x86/include/ -I$(srctree)/arch/x86/lib/ + +# Dependancies are also needed. +$(obj)/test_get_len.o: $(srctree)/arch/x86/lib/insn.c $(srctree)/arch/x86/lib/inat.c $(srctree)/arch/x86/include/asm/inat_types.h $(srctree)/arch/x86/include/asm/inat.h $(srctree)/arch/x86/include/asm/insn.h $(objtree)/arch/x86/lib/inat-tables.c + diff --git a/arch/x86/tools/distill.awk b/arch/x86/tools/distill.awk new file mode 100644 index 0000000..d433619 --- /dev/null +++ b/arch/x86/tools/distill.awk @@ -0,0 +1,42 @@ +#!/bin/awk -f +# Usage: objdump -d a.out | awk -f distill.awk | ./test_get_len +# Distills the disassembly as follows: +# - Removes all lines except the disassembled instructions. +# - For instructions that exceed 1 line (7 bytes), crams all the hex bytes +# into a single line. +# - Remove bad(or prefix only) instructions + +BEGIN { + prev_addr = "" + prev_hex = "" + prev_mnemonic = "" + bad_expr = "(\\(bad\\)|^rex|^.byte|^rep(z|nz)$|^lock$|^es$|^cs$|^ss$|^ds$|^fs$|^gs$|^data(16|32)$|^addr(16|32|64))" + fwait_expr = "^9b " + fwait_str="9b\tfwait" +} + +/^ *[0-9a-f]+:/ { + if (split($0, field, "\t") < 3) { + # This is a continuation of the same insn. + prev_hex = prev_hex field[2] + } else { + # Skip bad instructions + if (match(prev_mnemonic, bad_expr)) + prev_addr = "" + # Split fwait from other f* instructions + if (match(prev_hex, fwait_expr) && prev_mnemonic != "fwait") { + printf "%s\t%s\n", prev_addr, fwait_str + sub(fwait_expr, "", prev_hex) + } + if (prev_addr != "") + printf "%s\t%s\t%s\n", prev_addr, prev_hex, prev_mnemonic + prev_addr = field[1] + prev_hex = field[2] + prev_mnemonic = field[3] + } +} + +END { + if (prev_addr != "") + printf "%s\t%s\t%s\n", prev_addr, prev_hex, prev_mnemonic +} diff --git a/arch/x86/tools/test_get_len.c b/arch/x86/tools/test_get_len.c new file mode 100644 index 0000000..1e81adb --- /dev/null +++ b/arch/x86/tools/test_get_len.c @@ -0,0 +1,113 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * Copyright (C) IBM Corporation, 2009 + */ + +#include +#include +#include +#include + +#ifdef __x86_64__ +#define CONFIG_X86_64 +#else +#define CONFIG_X86_32 +#endif +#define unlikely(cond) (cond) + +#include +#include +#include + +/* + * Test of instruction analysis in general and insn_get_length() in + * particular. See if insn_get_length() and the disassembler agree + * on the length of each instruction in an elf disassembly. + * + * Usage: objdump -d a.out | awk -f distill.awk | ./test_get_len + */ + +const char *prog; + +static void usage(void) +{ + fprintf(stderr, "Usage: objdump -d a.out | awk -f distill.awk |" + " ./test_get_len\n"); + exit(1); +} + +static void malformed_line(const char *line, int line_nr) +{ + fprintf(stderr, "%s: malformed line %d:\n%s", prog, line_nr, line); + exit(3); +} + +#define BUFSIZE 256 + +int main(int argc, char **argv) +{ + char line[BUFSIZE]; + unsigned char insn_buf[16]; + struct insn insn; + int insns = 0; + + prog = argv[0]; + if (argc > 1) + usage(); + + while (fgets(line, BUFSIZE, stdin)) { + char copy[BUFSIZE], *s, *tab1, *tab2; + int nb = 0; + unsigned int b; + + insns++; + memset(insn_buf, 0, 16); + strcpy(copy, line); + tab1 = strchr(copy, '\t'); + if (!tab1) + malformed_line(line, insns); + s = tab1 + 1; + s += strspn(s, " "); + tab2 = strchr(s, '\t'); + if (!tab2) + malformed_line(line, insns); + *tab2 = '\0'; /* Characters beyond tab2 aren't examined */ + while (s < tab2) { + if (sscanf(s, "%x", &b) == 1) { + insn_buf[nb++] = (unsigned char) b; + s += 3; + } else + break; + } + /* Decode an instruction */ +#ifdef __x86_64__ + insn_init(&insn, insn_buf, 1); +#else + insn_init(&insn, insn_buf, 0); +#endif + insn_get_length(&insn); + if (insn.length != nb) { + fprintf(stderr, "Error: %s", line); + fprintf(stderr, "Error: objdump says %d bytes, but " + "insn_get_length() says %d (attr:%x)\n", nb, + insn.length, insn.attr); + exit(2); + } + } + fprintf(stderr, "Succeed: decoded and checked %d instructions\n", + insns); + return 0; +}