linux-yocto/scripts/decodecode

#!/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

PC=hex - the PC (program counter) the oops points to

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 ;;
3. type=4byte ;; esac

if [ -z "$ARCH" ]; then case uname -m in aarch64*) ARCH=arm64 ;; arm*) ARCH=arm ;; esac fi

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 [ $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

}

marker=expr index "$code" "\<" if [ $marker -eq 0 ]; then marker=expr index "$code" "\(" fi

touch $T.oo if [ $marker -ne 0 ]; then # 2 opcode bytes and a single space pc_sub=$(( $marker / 3 )) 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 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 $code | sed -e 's/\r//;s/ [<(]/ /;s/[>)] / /;s/ /,0x/g; s/[>)]$//' echo -n " .$type 0x" > $T.s echo $code >> $T.s disas $T 0 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