projects/linux·blob v7.1-rc6 · refs

251 lines · 4.9 KiB

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 $T.dis
15}
16
17die() {
18 echo "$@"
19 exit 1
20}
21
22trap cleanup EXIT
23
24T=`mktemp` || die "cannot create temp file"
25code=
26cont=
27
28while read i ; do
29
30case "$i" in
31*Code:*)
32 code=$i
33 cont=yes
34 ;;
35*)
36 [ -n "$cont" ] && {
37 xdump="$(echo $i | grep '^[[:xdigit:]<>[:space:]]\+$')"
38 if [ -n "$xdump" ]; then
39 code="$code $xdump"
40 else
41 cont=
42 fi
43 }
44 ;;
45esac
46
47done
48
49if [ -z "$code" ]; then
50 rm $T
51 die "Code line not found"
52fi
53
54echo $code
55code=`echo $code | sed -e 's/.*Code: //'`
56
57width=`expr index "$code" ' '`
58width=$((($width-1)/2))
59case $width in
601) type=byte ;;
612) type=2byte ;;
624) type=4byte ;;
63esac
64
65if [ -z "$ARCH" ]; then
66 case `uname -m` in
67 aarch64*) ARCH=arm64 ;;
68 arm*) ARCH=arm ;;
69 loongarch*) ARCH=loongarch ;;
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 $t.o
94 fi
95
96 if [ "$ARCH" = "riscv" ]; then
97 OBJDUMPFLAGS="-M no-aliases --section=.text -D"
98 ${CROSS_COMPILE}strip $t.o
99 fi
100
101 if [ "$ARCH" = "loongarch" ]; then
102 ${CROSS_COMPILE}strip $t.o
103 fi
104
105 if [ $pc_sub -ne 0 ]; then
106 if [ $PC ]; then
107 adj_vma=$(( $PC - $pc_sub ))
108 OBJDUMPFLAGS="$OBJDUMPFLAGS --adjust-vma=$adj_vma"
109 fi
110 fi
111
112 ${CROSS_COMPILE}objdump $OBJDUMPFLAGS -S $t.o | \
113 grep -v "/tmp\|Disassembly\|\.text\|^$" > $t.dis 2>&1
114}
115
116# Match the maximum number of opcode bytes from @op_bytes contained within
117# @opline
118#
119# Params:
120# @op_bytes: The string of bytes from the Code: line
121# @opline: The disassembled line coming from objdump
122#
123# Returns:
124# The max number of opcode bytes from the beginning of @op_bytes which match
125# the opcode bytes in the objdump line.
126get_substr_opcode_bytes_num()
127{
128 local op_bytes=$1
129 local opline=$2
130
131 local retval=0
132 substr=""
133
134 for opc in $op_bytes;
135 do
136 substr+="$opc"
137
138 opcode="$substr"
139 if [ "$ARCH" = "riscv" ]; then
140 opcode=$(echo $opcode | tr ' ' '\n' | tac | tr -d '\n')
141 fi
142
143 # return if opcode bytes do not match @opline anymore
144 if ! echo $opline | grep -q "$opcode";
145 then
146 break
147 fi
148
149 # add trailing space
150 substr+=" "
151 retval=$((retval+1))
152 done
153
154 return $retval
155}
156
157# Return the line number in objdump output to where the IP marker in the Code:
158# line points to
159#
160# Params:
161# @all_code: code in bytes without the marker
162# @dis_file: disassembled file
163# @ip_byte: The byte to which the IP points to
164get_faultlinenum()
165{
166 local all_code="$1"
167 local dis_file="$2"
168
169 # num bytes including IP byte
170 local num_bytes_ip=$(( $3 + 1 * $width ))
171
172 # Add the two header lines (we're counting from 1).
173 local retval=3
174
175 # remove marker
176 all_code=$(echo $all_code | sed -e 's/[<>()]//g')
177
178 while read line
179 do
180 get_substr_opcode_bytes_num "$all_code" "$line"
181 ate_opcodes=$?
182
183 if ! (( $ate_opcodes )); then
184 continue
185 fi
186
187 num_bytes_ip=$((num_bytes_ip - ($ate_opcodes * $width) ))
188 if (( $num_bytes_ip <= 0 )); then
189 break
190 fi
191
192 # Delete matched opcode bytes from all_code. For that, compute
193 # how many chars those opcodes are represented by and include
194 # trailing space.
195 #
196 # a byte is 2 chars, ate_opcodes is also the number of trailing
197 # spaces
198 del_chars=$(( ($ate_opcodes * $width * 2) + $ate_opcodes ))
199
200 all_code=$(echo $all_code | sed -e "s!^.\{$del_chars\}!!")
201
202 let "retval+=1"
203
204 done < $dis_file
205
206 return $retval
207}
208
209marker=`expr index "$code" "\<"`
210if [ $marker -eq 0 ]; then
211 marker=`expr index "$code" "\("`
212fi
213
214touch $T.oo
215if [ $marker -ne 0 ]; then
216 # How many bytes to subtract from the program counter
217 # in order to get to the beginning virtual address of the
218 # Code:
219 pc_sub=$(( (($marker - 1) / (2 * $width + 1)) * $width ))
220 echo All code >> $T.oo
221 echo ======== >> $T.oo
222 beforemark=`echo "$code"`
223 echo -n " .$type 0x" > $T.s
224
225 echo $beforemark | sed -e 's/ /,0x/g; s/[<>()]//g' >> $T.s
226
227 disas $T $pc_sub
228
229 cat $T.dis >> $T.oo
230
231 get_faultlinenum "$code" "$T.dis" $pc_sub
232 faultlinenum=$?
233
234 # and fix code at-and-after marker
235 code=`echo "$code" | cut -c$((${marker} + 1))-`
236
237 rm -f $T.o $T.s $T.dis
238fi
239
240echo Code starting with the faulting instruction > $T.aa
241echo =========================================== >> $T.aa
242code=`echo $code | sed -e 's/\r//;s/ [<(]/ /;s/[>)] / /;s/ /,0x/g; s/[>)]$//'`
243echo -n " .$type 0x" > $T.s
244echo $code >> $T.s
245disas $T 0
246cat $T.dis >> $T.aa
247
248cat $T.oo | sed -e "${faultlinenum}s/^\([^:]*:\)\(.*\)/\1\*\2\t\t<-- trapping instruction/"
249echo
250cat $T.aa
251cleanup