1#!/bin/sh
2# SPDX-License-Identifier: GPL-2.0
3# Disassemble the Code: line in Linux oopses
4# usage: decodecode < oops.file
5#
6# options: set env. variable AFLAGS=options to pass options to "as";
7# e.g., to decode an i386 oops on an x86_64 system, use:
8# AFLAGS=--32 decodecode < 386.oops
9
10cleanup() {
11	rm -f $T $T.s $T.o $T.oo $T.aa $T.dis
12	exit 1
13}
14
15die() {
16	echo "$@"
17	exit 1
18}
19
20trap cleanup EXIT
21
22T=`mktemp` || die "cannot create temp file"
23code=
24cont=
25
26while read i ; do
27
28case "$i" in
29*Code:*)
30	code=$i
31	cont=yes
32	;;
33*)
34	[ -n "$cont" ] && {
35		xdump="$(echo $i | grep '^[[:xdigit:]<>[:space:]]\+$')"
36		if [ -n "$xdump" ]; then
37			code="$code $xdump"
38		else
39			cont=
40		fi
41	}
42	;;
43esac
44
45done
46
47if [ -z "$code" ]; then
48	rm $T
49	exit
50fi
51
52echo $code
53code=`echo $code | sed -e 's/.*Code: //'`
54
55width=`expr index "$code" ' '`
56width=$((($width-1)/2))
57case $width in
581) type=byte ;;
592) type=2byte ;;
604) type=4byte ;;
61esac
62
63disas() {
64	${CROSS_COMPILE}as $AFLAGS -o $1.o $1.s > /dev/null 2>&1
65
66	if [ "$ARCH" = "arm" ]; then
67		if [ $width -eq 2 ]; then
68			OBJDUMPFLAGS="-M force-thumb"
69		fi
70
71		${CROSS_COMPILE}strip $1.o
72	fi
73
74	if [ "$ARCH" = "arm64" ]; then
75		if [ $width -eq 4 ]; then
76			type=inst
77		fi
78
79		${CROSS_COMPILE}strip $1.o
80	fi
81
82	${CROSS_COMPILE}objdump $OBJDUMPFLAGS -S $1.o | \
83		grep -v "/tmp\|Disassembly\|\.text\|^$" > $1.dis 2>&1
84}
85
86marker=`expr index "$code" "\<"`
87if [ $marker -eq 0 ]; then
88	marker=`expr index "$code" "\("`
89fi
90
91touch $T.oo
92if [ $marker -ne 0 ]; then
93	echo All code >> $T.oo
94	echo ======== >> $T.oo
95	beforemark=`echo "$code"`
96	echo -n "	.$type 0x" > $T.s
97	echo $beforemark | sed -e 's/ /,0x/g; s/[<>()]//g' >> $T.s
98	disas $T
99	cat $T.dis >> $T.oo
100	rm -f $T.o $T.s $T.dis
101
102# and fix code at-and-after marker
103	code=`echo "$code" | cut -c$((${marker} + 1))-`
104fi
105echo Code starting with the faulting instruction  > $T.aa
106echo =========================================== >> $T.aa
107code=`echo $code | sed -e 's/ [<(]/ /;s/[>)] / /;s/ /,0x/g; s/[>)]$//'`
108echo -n "	.$type 0x" > $T.s
109echo $code >> $T.s
110disas $T
111cat $T.dis >> $T.aa
112
113# (lines of whole $T.oo) - (lines of $T.aa, i.e. "Code starting") + 3,
114# i.e. the title + the "===..=" line (sed is counting from 1, 0 address is
115# special)
116faultlinenum=$(( $(wc -l $T.oo  | cut -d" " -f1) - \
117		 $(wc -l $T.aa  | cut -d" " -f1) + 3))
118
119faultline=`cat $T.dis | head -1 | cut -d":" -f2-`
120faultline=`echo "$faultline" | sed -e 's/\[/\\\[/g; s/\]/\\\]/g'`
121
122cat $T.oo | sed -e "${faultlinenum}s/^\(.*:\)\(.*\)/\1\*\2\t\t<-- trapping instruction/"
123echo
124cat $T.aa
125cleanup
126