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  • #!/bin/sh
    # 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
    
    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
    	exit
    fi
    
    echo $code
    code=`echo $code | sed -e 's/.*Code: //'`
    
    width=`expr index "$code" ' '`
    width=$((($width-1)/2))
    case $width in
    1) type=byte ;;
    2) type=2byte ;;
    4) type=4byte ;;
    esac
    
    disas() {
    	${CROSS_COMPILE}as $AFLAGS -o $1.o $1.s > /dev/null 2>&1
    
    	if [ "$ARCH" = "arm" ]; then
    		if [ $width -eq 2 ]; then
    			OBJDUMPFLAGS="-M force-thumb"
    		fi
    
    		${CROSS_COMPILE}strip $1.o
    	fi
    
    	if [ "$ARCH" = "arm64" ]; then
    		if [ $width -eq 4 ]; then
    			type=inst
    		fi
    
    		${CROSS_COMPILE}strip $1.o
    	fi
    
    	${CROSS_COMPILE}objdump $OBJDUMPFLAGS -S $1.o | \
    		grep -v "/tmp\|Disassembly\|\.text\|^$" > $1.dis 2>&1
    }
    
    marker=`expr index "$code" "\<"`
    if [ $marker -eq 0 ]; then
    	marker=`expr index "$code" "\("`
    fi
    
    touch $T.oo
    if [ $marker -ne 0 ]; then
    	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
    	cat $T.dis >> $T.oo
    	rm -f $T.o $T.s $T.dis
    
    # and fix code at-and-after marker
    	code=`echo "$code" | cut -c$((${marker} + 1))-`
    fi
    echo Code starting with the faulting instruction  > $T.aa
    echo =========================================== >> $T.aa
    code=`echo $code | sed -e 's/ [<(]/ /;s/[>)] / /;s/ /,0x/g; s/[>)]$//'`
    echo -n "	.$type 0x" > $T.s
    echo $code >> $T.s
    disas $T
    cat $T.dis >> $T.aa
    
    # (lines of whole $T.oo) - (lines of $T.aa, i.e. "Code starting") + 3,
    # i.e. the title + the "===..=" line (sed is counting from 1, 0 address is
    # special)
    faultlinenum=$(( $(wc -l $T.oo  | cut -d" " -f1) - \
    		 $(wc -l $T.aa  | cut -d" " -f1) + 3))
    
    faultline=`cat $T.dis | head -1 | cut -d":" -f2-`
    faultline=`echo "$faultline" | sed -e 's/\[/\\\[/g; s/\]/\\\]/g'`
    
    cat $T.oo | sed -e "${faultlinenum}s/^\(.*:\)\(.*\)/\1\*\2\t\t<-- trapping instruction/"
    echo
    cat $T.aa
    cleanup