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1#!/bin/bash
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# PC=hex - the PC (program counter) the oops points to
10
11faultlinenum=1
12
13cleanup() {
14 rm -f $T $T.s $T.o $T.oo $T.aa $T.dis
15 exit 1
16}
17
18die() {
19 echo "$@"
20 exit 1
21}
22
23trap cleanup EXIT
24
25T=`mktemp` || die "cannot create temp file"
26code=
27cont=
28
29while read i ; do
30
31case "$i" in
32*Code:*)
33 code=$i
34 cont=yes
35 ;;
36*)
37 [ -n "$cont" ] && {
38 xdump="$(echo $i | grep '^[[:xdigit:]<>[:space:]]\+$')"
39 if [ -n "$xdump" ]; then
40 code="$code $xdump"
41 else
42 cont=
43 fi
44 }
45 ;;
46esac
47
48done
49
50if [ -z "$code" ]; then
51 rm $T
52 exit
53fi
54
55echo $code
56code=`echo $code | sed -e 's/.*Code: //'`
57
58width=`expr index "$code" ' '`
59width=$((($width-1)/2))
60case $width in
611) type=byte ;;
622) type=2byte ;;
634) type=4byte ;;
64esac
65
66if [ -z "$ARCH" ]; then
67 case `uname -m` in
68 aarch64*) ARCH=arm64 ;;
69 arm*) ARCH=arm ;;
70 esac
71fi
72
73# Params: (tmp_file, pc_sub)
74disas() {
75 t=$1
76 pc_sub=$2
77
78 ${CROSS_COMPILE}as $AFLAGS -o $t.o $t.s > /dev/null 2>&1
79
80 if [ "$ARCH" = "arm" ]; then
81 if [ $width -eq 2 ]; then
82 OBJDUMPFLAGS="-M force-thumb"
83 fi
84
85 ${CROSS_COMPILE}strip $t.o
86 fi
87
88 if [ "$ARCH" = "arm64" ]; then
89 if [ $width -eq 4 ]; then
90 type=inst
91 fi
92
93 ${CROSS_COMPILE}strip $t.o
94 fi
95
96 if [ $pc_sub -ne 0 ]; then
97 if [ $PC ]; then
98 adj_vma=$(( $PC - $pc_sub ))
99 OBJDUMPFLAGS="$OBJDUMPFLAGS --adjust-vma=$adj_vma"
100 fi
101 fi
102
103 ${CROSS_COMPILE}objdump $OBJDUMPFLAGS -S $t.o | \
104 grep -v "/tmp\|Disassembly\|\.text\|^$" > $t.dis 2>&1
105}
106
107# Match the maximum number of opcode bytes from @op_bytes contained within
108# @opline
109#
110# Params:
111# @op_bytes: The string of bytes from the Code: line
112# @opline: The disassembled line coming from objdump
113#
114# Returns:
115# The max number of opcode bytes from the beginning of @op_bytes which match
116# the opcode bytes in the objdump line.
117get_substr_opcode_bytes_num()
118{
119 local op_bytes=$1
120 local opline=$2
121
122 local retval=0
123 substr=""
124
125 for opc in $op_bytes;
126 do
127 substr+="$opc"
128
129 # return if opcode bytes do not match @opline anymore
130 if ! echo $opline | grep -q "$substr";
131 then
132 break
133 fi
134
135 # add trailing space
136 substr+=" "
137 retval=$((retval+1))
138 done
139
140 return $retval
141}
142
143# Return the line number in objdump output to where the IP marker in the Code:
144# line points to
145#
146# Params:
147# @all_code: code in bytes without the marker
148# @dis_file: disassembled file
149# @ip_byte: The byte to which the IP points to
150get_faultlinenum()
151{
152 local all_code="$1"
153 local dis_file="$2"
154
155 # num bytes including IP byte
156 local num_bytes_ip=$(( $3 + 1 * $width ))
157
158 # Add the two header lines (we're counting from 1).
159 local retval=3
160
161 # remove marker
162 all_code=$(echo $all_code | sed -e 's/[<>()]//g')
163
164 while read line
165 do
166 get_substr_opcode_bytes_num "$all_code" "$line"
167 ate_opcodes=$?
168
169 if ! (( $ate_opcodes )); then
170 continue
171 fi
172
173 num_bytes_ip=$((num_bytes_ip - ($ate_opcodes * $width) ))
174 if (( $num_bytes_ip <= 0 )); then
175 break
176 fi
177
178 # Delete matched opcode bytes from all_code. For that, compute
179 # how many chars those opcodes are represented by and include
180 # trailing space.
181 #
182 # a byte is 2 chars, ate_opcodes is also the number of trailing
183 # spaces
184 del_chars=$(( ($ate_opcodes * $width * 2) + $ate_opcodes ))
185
186 all_code=$(echo $all_code | sed -e "s!^.\{$del_chars\}!!")
187
188 let "retval+=1"
189
190 done < $dis_file
191
192 return $retval
193}
194
195marker=`expr index "$code" "\<"`
196if [ $marker -eq 0 ]; then
197 marker=`expr index "$code" "\("`
198fi
199
200touch $T.oo
201if [ $marker -ne 0 ]; then
202 # How many bytes to subtract from the program counter
203 # in order to get to the beginning virtual address of the
204 # Code:
205 pc_sub=$(( (($marker - 1) / (2 * $width + 1)) * $width ))
206 echo All code >> $T.oo
207 echo ======== >> $T.oo
208 beforemark=`echo "$code"`
209 echo -n " .$type 0x" > $T.s
210
211 echo $beforemark | sed -e 's/ /,0x/g; s/[<>()]//g' >> $T.s
212
213 disas $T $pc_sub
214
215 cat $T.dis >> $T.oo
216
217 get_faultlinenum "$code" "$T.dis" $pc_sub
218 faultlinenum=$?
219
220 # and fix code at-and-after marker
221 code=`echo "$code" | cut -c$((${marker} + 1))-`
222
223 rm -f $T.o $T.s $T.dis
224fi
225
226echo Code starting with the faulting instruction > $T.aa
227echo =========================================== >> $T.aa
228code=`echo $code | sed -e 's/\r//;s/ [<(]/ /;s/[>)] / /;s/ /,0x/g; s/[>)]$//'`
229echo -n " .$type 0x" > $T.s
230echo $code >> $T.s
231disas $T 0
232cat $T.dis >> $T.aa
233
234cat $T.oo | sed -e "${faultlinenum}s/^\([^:]*:\)\(.*\)/\1\*\2\t\t<-- trapping instruction/"
235echo
236cat $T.aa
237cleanup
1#!/bin/sh
2# Disassemble the Code: line in Linux oopses
3# usage: decodecode < oops.file
4#
5# options: set env. variable AFLAGS=options to pass options to "as";
6# e.g., to decode an i386 oops on an x86_64 system, use:
7# AFLAGS=--32 decodecode < 386.oops
8
9cleanup() {
10 rm -f $T $T.s $T.o $T.oo $T.aa $T.dis
11 exit 1
12}
13
14die() {
15 echo "$@"
16 exit 1
17}
18
19trap cleanup EXIT
20
21T=`mktemp` || die "cannot create temp file"
22code=
23
24while read i ; do
25
26case "$i" in
27*Code:*)
28 code=$i
29 ;;
30esac
31
32done
33
34if [ -z "$code" ]; then
35 rm $T
36 exit
37fi
38
39echo $code
40code=`echo $code | sed -e 's/.*Code: //'`
41
42width=`expr index "$code" ' '`
43width=$((($width-1)/2))
44case $width in
451) type=byte ;;
462) type=2byte ;;
474) type=4byte ;;
48esac
49
50disas() {
51 ${CROSS_COMPILE}as $AFLAGS -o $1.o $1.s > /dev/null 2>&1
52
53 if [ "$ARCH" = "arm" ]; then
54 if [ $width -eq 2 ]; then
55 OBJDUMPFLAGS="-M force-thumb"
56 fi
57
58 ${CROSS_COMPILE}strip $1.o
59 fi
60
61 ${CROSS_COMPILE}objdump $OBJDUMPFLAGS -S $1.o | \
62 grep -v "/tmp\|Disassembly\|\.text\|^$" > $1.dis 2>&1
63}
64
65marker=`expr index "$code" "\<"`
66if [ $marker -eq 0 ]; then
67 marker=`expr index "$code" "\("`
68fi
69
70touch $T.oo
71if [ $marker -ne 0 ]; then
72 echo All code >> $T.oo
73 echo ======== >> $T.oo
74 beforemark=`echo "$code"`
75 echo -n " .$type 0x" > $T.s
76 echo $beforemark | sed -e 's/ /,0x/g; s/[<>()]//g' >> $T.s
77 disas $T
78 cat $T.dis >> $T.oo
79 rm -f $T.o $T.s $T.dis
80
81# and fix code at-and-after marker
82 code=`echo "$code" | cut -c$((${marker} + 1))-`
83fi
84echo Code starting with the faulting instruction > $T.aa
85echo =========================================== >> $T.aa
86code=`echo $code | sed -e 's/ [<(]/ /;s/[>)] / /;s/ /,0x/g; s/[>)]$//'`
87echo -n " .$type 0x" > $T.s
88echo $code >> $T.s
89disas $T
90cat $T.dis >> $T.aa
91
92faultline=`cat $T.dis | head -1 | cut -d":" -f2`
93faultline=`echo "$faultline" | sed -e 's/\[/\\\[/g; s/\]/\\\]/g'`
94
95cat $T.oo | sed -e "s/\($faultline\)/\*\1 <-- trapping instruction/g"
96echo
97cat $T.aa
98cleanup