#!/bin/bash# SPDX-License-Identifier: GPL-2.0# Disassemble the Code: line in Linux oopses# usage: decodecode < oops.file## options: set env. variable AFLAGS=options to pass options to "as";# e.g., to decode an i386 oops on an x86_64 system, use:# AFLAGS=--32 decodecode < 386.oops# PC=hex - the PC (program counter) the oops points to faultlinenum=1 cleanup() {	rm -f $T $T.s $T.o $T.oo $T.aa $T.dis	exit 1} die() {	echo "$@"	exit 1} trap cleanup EXIT T=`mktemp` || die "cannot create temp file"code=cont= while read i ; do case "$i" in*Code:*)	code=$i	cont=yes	;;*)	[ -n "$cont" ] && {		xdump="$(echo $i | grep '^[[:xdigit:]<>[:space:]]\+$')"		if [ -n "$xdump" ]; then			code="$code $xdump"		else			cont=		fi	}	;;esac done if [ -z "$code" ]; then	rm $T	exitfi echo $codecode=`echo $code | sed -e 's/.*Code: //'` width=`expr index "$code" ' '`width=$((($width-1)/2))case $width in1) type=byte ;;2) type=2byte ;;4) type=4byte ;;esac if [ -z "$ARCH" ]; then    case `uname -m` in	aarch64*) ARCH=arm64 ;;	arm*) ARCH=arm ;;	loongarch*) ARCH=loongarch ;;    esacfi # Params: (tmp_file, pc_sub)disas() {	t=$1	pc_sub=$2 	${CROSS_COMPILE}as $AFLAGS -o $t.o $t.s > /dev/null 2>&1 	if [ "$ARCH" = "arm" ]; then		if [ $width -eq 2 ]; then			OBJDUMPFLAGS="-M force-thumb"		fi 		${CROSS_COMPILE}strip $t.o	fi 	if [ "$ARCH" = "arm64" ]; then		if [ $width -eq 4 ]; then			type=inst		fi 		${CROSS_COMPILE}strip $t.o	fi 	if [ "$ARCH" = "riscv" ]; then		OBJDUMPFLAGS="-M no-aliases --section=.text -D"		${CROSS_COMPILE}strip $t.o	fi 	if [ "$ARCH" = "loongarch" ]; then		${CROSS_COMPILE}strip $t.o	fi 	if [ $pc_sub -ne 0 ]; then		if [ $PC ]; then			adj_vma=$(( $PC - $pc_sub ))			OBJDUMPFLAGS="$OBJDUMPFLAGS --adjust-vma=$adj_vma"		fi	fi 	${CROSS_COMPILE}objdump $OBJDUMPFLAGS -S $t.o | \		grep -v "/tmp\|Disassembly\|\.text\|^$" > $t.dis 2>&1} # Match the maximum number of opcode bytes from @op_bytes contained within# @opline## Params:# @op_bytes: The string of bytes from the Code: line# @opline: The disassembled line coming from objdump## Returns:# The max number of opcode bytes from the beginning of @op_bytes which match# the opcode bytes in the objdump line.get_substr_opcode_bytes_num(){	local op_bytes=$1	local opline=$2 	local retval=0	substr="" 	for opc in $op_bytes;	do		substr+="$opc" 		opcode="$substr"		if [ "$ARCH" = "riscv" ]; then			opcode=$(echo $opcode | tr ' ' '\n' | tac | tr -d '\n')		fi 		# return if opcode bytes do not match @opline anymore		if ! echo $opline | grep -q "$opcode";		then			break		fi 		# add trailing space		substr+=" "		retval=$((retval+1))	done 	return $retval} # Return the line number in objdump output to where the IP marker in the Code:# line points to## Params:# @all_code: code in bytes without the marker# @dis_file: disassembled file# @ip_byte: The byte to which the IP points toget_faultlinenum(){	local all_code="$1"	local dis_file="$2" 	# num bytes including IP byte	local num_bytes_ip=$(( $3 + 1 * $width )) 	# Add the two header lines (we're counting from 1).	local retval=3 	# remove marker	all_code=$(echo $all_code | sed -e 's/[<>()]//g') 	while read line	do		get_substr_opcode_bytes_num "$all_code" "$line"		ate_opcodes=$? 		if ! (( $ate_opcodes )); then			continue		fi 		num_bytes_ip=$((num_bytes_ip - ($ate_opcodes * $width) ))		if (( $num_bytes_ip <= 0 )); then			break		fi 		# Delete matched opcode bytes from all_code. For that, compute		# how many chars those opcodes are represented by and include		# trailing space.		#		# a byte is 2 chars, ate_opcodes is also the number of trailing		# spaces		del_chars=$(( ($ate_opcodes * $width * 2) + $ate_opcodes )) 		all_code=$(echo $all_code | sed -e "s!^.\{$del_chars\}!!") 		let "retval+=1" 	done < $dis_file 	return $retval} marker=`expr index "$code" "\<"`if [ $marker -eq 0 ]; then	marker=`expr index "$code" "\("`fi touch $T.ooif [ $marker -ne 0 ]; then	# How many bytes to subtract from the program counter	# in order to get to the beginning virtual address of the	# Code:	pc_sub=$(( (($marker - 1) / (2 * $width + 1)) * $width ))	echo All code >> $T.oo	echo ======== >> $T.oo	beforemark=`echo "$code"`	echo -n "	.$type 0x" > $T.s 	echo $beforemark | sed -e 's/ /,0x/g; s/[<>()]//g' >> $T.s 	disas $T $pc_sub 	cat $T.dis >> $T.oo 	get_faultlinenum "$code" "$T.dis" $pc_sub	faultlinenum=$? 	# and fix code at-and-after marker	code=`echo "$code" | cut -c$((${marker} + 1))-` 	rm -f $T.o $T.s $T.disfi echo Code starting with the faulting instruction  > $T.aaecho =========================================== >> $T.aacode=`echo $code | sed -e 's/\r//;s/ [<(]/ /;s/[>)] / /;s/ /,0x/g; s/[>)]$//'`echo -n "	.$type 0x" > $T.secho $code >> $T.sdisas $T 0cat $T.dis >> $T.aa cat $T.oo | sed -e "${faultlinenum}s/^\([^:]*:\)\(.*\)/\1\*\2\t\t<-- trapping instruction/"echocat $T.aacleanup