diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index d105f29bb6bb..7d0b681a132b 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 1b68659c41b4..5fe16bfd15ac 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 000000000000..3dd626b99dc8 --- /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 $(objtree)/arch/x86/lib/inat-tables.c + diff --git a/arch/x86/tools/distill.awk b/arch/x86/tools/distill.awk new file mode 100644 index 000000000000..d433619bb866 --- /dev/null +++ b/arch/x86/tools/distill.awk @@ -0,0 +1,42 @@ +#!/bin/awk -f +# Usage: objdump -d a.out | awk -f distill.awk | ./test_get_len +# Distills the disassembly as follows: +# - Removes all lines except the disassembled instructions. +# - For instructions that exceed 1 line (7 bytes), crams all the hex bytes +# into a single line. +# - Remove bad(or prefix only) instructions + +BEGIN { + prev_addr = "" + prev_hex = "" + prev_mnemonic = "" + bad_expr = "(\\(bad\\)|^rex|^.byte|^rep(z|nz)$|^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 000000000000..1e81adb2d8a9 --- /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; +}